August 2002 Scanning Systems, Computed Tomography, Full-Body Purpose CT scanners produce thin cross-sectional images of the human body for a wide variety of diagnostic proce- dures. CT is a noninvasive radiographic technique that involves the reconstruction of a tomographic plane of the body (a slice) from a large number of collected x-ray absorption measurements taken during a scan around the body’s periphery. The result of a CT study is usually a set of transaxial slices, which can be mathe- matically manipulated to produce sagittal or coronal image slices. See Figure 1 for an illustration of body planes. CT is clinically useful in a wide variety of imaging exams, including spine and head, gastrointestinal, and vascular. Principles of operation Components of a CT system A CT system consists of an x-ray subsystem, a gantry, a patient table, and a controlling computer. A high-voltage x-ray generator supplies electric power to 174073 424-010 Scope of this Product Comparison This Product Comparison covers computed to- mography (CT) scanners used to obtain cross- sectional images without restriction to a particu- lar anatomic region. It also covers the CT compo- nents of combined positron emission tomography (PET)/computed tomography (CT) systems. For PET component information, see the report ti- tled SCANNING SYSTEMS, POSITRON EMISSION TOMOGRAPHY. UMDNS information This Product Comparison covers the following device terms and product codes as listed in ECRI’s Universal Medical Device Nomenclature System™ (UMDNS™): • Scanning Systems, Computed Tomography, Axial, Full-Body [15-956] • Scanning Systems, Computed Tomography, Electron Beam [16-899] • Scanning Systems, Computed Tomography, Spiral [18-443] • Scanning Systems, Computed Tomography/ Positron Emission Tomography [20-161] 5200 Butler Pike, Plymouth Meeting, PA 19462-1298, USA Telephone +1 (610) 825-6000 ● Fax +1 (610) 834-1275 ● E-mail [email protected]
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Transcript
August 2002
Scanning Systems, Computed Tomography,Full-Body
Purpose
CT scanners produce thin cross-sectional images ofthe human body for a wide variety of diagnostic proce-dures. CT is a noninvasive radiographic technique that
involves the reconstruction of a tomographic plane ofthe body (a slice) from a large number of collected x-rayabsorption measurements taken during a scan aroundthe body’s periphery. The result of a CT study isusually a set of transaxial slices, which can be mathe-matically manipulated to produce sagittal or coronalimage slices. See Figure 1 for an illustration of bodyplanes.
CT is clinically useful in a wide variety of imagingexams, including spine and head, gastrointestinal, andvascular.
Principles of operationComponents of a CT system
A CT system consists of an x-ray subsystem, agantry, a patient table, and a controlling computer. Ahigh-voltage x-ray generator supplies electric power to
174073424-010
Scope of this Product ComparisonThis Product Comparison covers computed to-mography (CT) scanners used to obtain cross-sectional images without restriction to a particu-lar anatomic region. It also covers the CT compo-nents of combined positron emission tomography(PET)/computed tomography (CT) systems. ForPET component information, see the report ti-tled SCANNING SYSTEMS, POSITRON EMISSIONTOMOGRAPHY.
UMDNS informationThis Product Comparison covers the followingdevice terms and product codes as listed inECRI’s Universal Medical Device NomenclatureSystem™ (UMDNS™):
the x-ray tube, which usually has a rotating anode andis capable of withstanding the high heat loads gener-ated during rapid multiple-slice acquisition.
The gantry houses the x-ray tube, detector system,collimators, and rotational circuitry; in some scanners,it also contains a compact, high-frequency x-ray gener-ator. Two types of detectors are used in CT scanners.Xenon-gas ionization chamber detectors produce a cur-rent (the output signal) when incoming radiation ion-izes xenon atoms; this signal is proportional to theintensity of the radiation. Solid-state detectors con-tain cesium-iodide or cadmium-tungstate crystals thatproduce light when exposed to ionizing radiation. Sili-con photodiodes convert this light into an electricalsignal.
The xenon gas in the ionization chambers is at highpressure (25 atm) to increase the detection efficiencyof these chambers. Each solid-state detector has ahigher detection efficiency than an individual xenon-gas ionization chamber, but ionization chambers canbe packed more densely than solid-state detectors. Thenet result is that the overall detection efficiencies for
solid-state and ionization chamber arrays are verysimilar.
Collimators located near the x-ray tube and at eachdetector are aligned so that scatter radiation is mini-mized and the x-ray beam is properly defined forscanning. The separation of the collimators definesthe thickness of the tomographic slice.
The patient table can be moved both vertically andhorizontally to accommodate various scanning posi-tions. During a CT scan, the table moves the patientinto the gantry, and the x-ray tube rotates around thepatient. As x-rays pass through the patient to thedetectors, the computer acquires and processes data toform an image. The computer also controls the x-rayproduction, gantry motions, table motions, and imagedisplay and storage.
Types of CT scanners
All currently marketed CT scanners use slip-ringtechnology introduced in 1989. Slip-ring CT scannersuse grooved copper bands or rings with a series ofelectrically conductive brushes that provide for con-tinuous one-way rotation of the gantry allowing rapidcontinuous scanning. Slip-ring scanners can performhelical (also called volumetric) CT scanning. In helicalscanning, the x-ray tube and detector rotate aroundthe patient’s body, continuously acquiring data whilethe patient moves through the gantry. The acquiredvolume of data can be reconstructed at any pointduring the scan. Because data is collected from avolume of tissue rather than section by section, slicesas thin as 1 mm can be reconstructed without increas-ing exam time. Advantages of helical CT include de-creased radiation dosage, fewer motion artifacts, andoptimization of contrast levels. Additionally, helicalCT improves lesion detection and decreases partialvolume artifacts. Helical CT techniques also shortenexam times (from 20 to 30 minutes for a conventionalexam to 5 to 10 minutes for a helical exam) to facilitateimaging of emergency cases and to somewhat increasepatient throughput. This faster scanning speed mini-mizes the effects of patient movement on image qualityand is, therefore, clinically advantageous for scanningtrauma victims and pediatric patients. Slower CTscanners also require the patient to maintain a longerbreathhold; however, helical CT’s faster scanningspeed also helps improve image quality for patientswho have trouble doing so.
Some manufacturers offer multislice scanners,which shorten scan time. A multislice CT scanner has —in addition to the gantry — a powerful computer proc-essor. Inside the gantry, an x-ray tube projects a fan-shaped x-ray beam through the patient to the detector
array. As the x-ray tube and detector rotate, x-rays aredetected at a number of angles through the patient.The computer mathematically reconstructs data fromeach full rotation to produce an image of one slice. Thesecond component is a detector design that incorpo-rates 1,000 elements along the length of the arc (x/yaxes) and between 8 and 34 elements across the width(z-axis) of the detector. In contrast, the detector in asingle-slice CT scanner is only divided into segmentsalong the length of the detector. When using a multis-lice CT scanner, the slice width is chosen by combiningdata from adjacent elements across the detector in thez-axis. This differs from single-slice CT scanning, inwhich the slice width is selected by controlling thewidth of the x-ray beam with collimators. The scannersuse multiple detectors to take multiple images (ormultiple slices) in each pass. Multislice CT technologyreduces the limitations caused by x-ray tube heatingand patient movement encountered in single-slice CTscanning.
Multislice CT scanners make more efficient use ofthe x-ray tube because the x-ray beam may be up to fourtimes wider than in a single-slice CT scanner. Howeverthe actual increase in tube life may not be as great asmight be expected because of other factors. In addition,multislice CT scanners can acquire the data needed forisometric voxel reconstruction faster than single-sliceCT scanners can. This means that larger volumes (e.g.,complete organs) can now be reconstructed with a use-ful spatial resolution in three dimensions. (Figure 2shows four CT images.) Helical and multislice CT arealso used for CT angiography (CTA), a technique forimaging the large blood vessels that is used to assessrenal artery stenosis, carotid bifurcation, and abdomi-nal aortic aneurysms. Multislice scanners can now ac-quire up to 16 slices simultaneously.
Developed in the mid-1980s, electron beam CT(EBCT) systems eliminate the mechanical movementof earlier designs by magnetically rotating an electronbeam that strikes a tungsten target ring, producing anx-ray fan beam from multiple angles around the 210°target. The detector array consists of two 210° rings,each with 420 cadmium-tungstate detectors, directlyopposite the target rings. Because only the electronbeam moves during data collection, the scan times canbe extremely short — on the order of 50 msec each. Scantimes of 10 msec are anticipated in the future. Theprincipal purpose of this design is to allow transaxialimaging of the beating heart without having to resortto electrocardiograph-gated data collection over severalcardiac cycles. Based on its very rapid (subsecond)image acquisition, clinical applications of ultrafast CTinclude quantification of coronary artery calcificationand pericardial disease, as well as geriatric, pediatric,
and trauma patient imaging (in which patient motioncould affect image acquisition).
Three-dimensional (3-D) CTA is used to assessaneurysms preoperatively and postoperatively, inplanning angiography and subsequent surgery, and tocomplement conventional angiography, ultrasound,and magnetic resonance angiography.
Additionally, studies suggest CT coronary scans(both helical and ultrafast) may detect coronary calci-fication as accurately as coronary angiography and/orintracoronary ultrasound (ICUS) most of the time.The significance of these studies is that CT coronaryscanning is the first noninvasive method for visualiz-ing, localizing, and quantifying coronary disease. Thisallows medical personnel to recognize potential coro-nary complications even if angiography and/or ICUSis not an option.
However, increased radiation exposure during thescan should be avoided. Imaging needs and patientsafety should dictate the scanning technique.
Some manufacturers also offer remote diagnostics,which allows for expedited handling of system prob-lems. With remote diagnostics, a supplier can down-load a software patch, order replacement parts, orimmediately alert a repair technician to problems.
Most systems offer archiving capabilities, whichallow personnel to recall the images at a later time forreview. For further information, see the Product Com-parison titled PICTURE ARCHIVING AND COMMUNICA-TIONS SYSTEMS (PACS), RADIOLOGY.
Figure 2. CT images: mid-brain (top left), chest (topright), spiral scan of abdomen (bottom left), spiralscan of pelvis (bottom right)
Many suppliers now offer specialized software forbone mineral analysis, dental CT, cerebral blood-flowanalysis, and pulmonary imaging. Additionally, theuse of ultrafast CT to detect coronary artery aneu-rysms that were undetectable by conventional angiog-raphy has been described (Kobayashi et al. 1997).
Image manipulation
The quantitative nature of the CT image allows thereviewer to perform a large number of image manipu-lations easily. Although the numerical range of pixelsin the image is rather large, the numerical rangespanned by most soft tissues is relatively narrow. Toadequately display the values for soft tissue and stillmaintain the ability to discriminate density differ-ences, CT scanners are designed to display user-selected CT numerical ranges (also called Hounsfieldunits) over the entire grayscale. The range to be dis-played (window width) and the central value (level) arealso user selectable.
Regions of interest in the image can be selected toobtain average CT values within the region or to cal-culate total lesion volume. CT-guided needle biopsiesare facilitated by the ability to measure distance andorientation between two operator-selected points inthe images.
The transaxial images obtained directly from thescanner can be reformatted into sagittal, coronal, andoblique images by software manipulation. Most cur-rent systems can also construct tomographic images atnonorthogonal orientations to provide a better displayof anatomic detail.
Most CT workstations are capable of 3-D imagereconstruction. Because anatomic relationships can bemore clearly visualized by a 3-D image display than bya planar image display, surgeons are using 3-D CTmore frequently for surgery simulations and for plan-ning reconstructive procedures. In addition, some soft-ware allows the 3-D image to be rotated to view avariety of perspectives. Clinical applications of 3-Dreconstruction include craniofacial surgical planning;postoperative evaluations; analysis of the pelvis, hip,and spine; CTA; and virtual colonoscopy.
Image quality and resolution
A number of factors combine to determine the qual-ity of the image produced by any CT scanner, includingradiation dose, number of attenuation measurementstaken, reconstruction algorithm, size of the digitalimage matrix, and presence or absence of artifacts. Therelationship between radiation dose, reconstructionfilter, and spatial resolution is such that, for high-contrast resolution (e.g., in the inner ear), the physical
design of the detector system determines the minimumdetectable lesion; beyond a certain point, nothing isgained by increasing the radiation exposure. As thelesion-to-background contrast ratio decreases, increas-ing the radiation dose and thereby decreasing thestatistical noise in the image produces an apparentincrease in spatial resolution. Low-contrast resolutioncan also be increased by using a reconstruction filter,which reduces the image noise. This relationship isimportant because it is used in soft-tissue imagingprocedures to increase the probability of detectinglow-contrast lesions, such as metastatic carcinoma inthe liver. Because of this interdependence, it is criticalthat all of the scan performance parameters (i.e., peakkilovoltage [kVp], milliamp-seconds [mAs], radiationdose, and reconstruction algorithm) be stated when-ever the spatial resolution of a scanner is quoted.
Contrast resolution in a CT scanner is directly re-lated to radiation dose and the efficiency with whichtransmitted x-rays are detected. Although the 0.3% to0.4% contrast resolution of current scanners could beincreased by longer scanning times or more intensex-ray beams, a clinically relevant improvement is un-likely without a significant increase in the radiationdose. More likely, improvements in contrast resolu-tion will result from changes in design and adjust-ments in the image reconstruction algorithms.
Spatial resolution in the final CT image can beimproved by several techniques, including limited fan-beam scanning and geometric magnification. Limitedfan-beam scanning increases resolution by collimatingthe x-ray beam so that it covers only the central 20 to25 cm of the gantry opening. Because the beam spansfewer detectors, the sampling rate is much quicker,and transmission measurements can be taken atsmaller angular increments during rotation; the finersampling, in turn, increases spatial resolution in thereconstructed image.
Radiation dose
CT uses some of the highest doses of any diagnosticimaging method, and the fact that multislice CT hasthe potential to increase these doses adds to the needfor some form of automatic dose control. CT manufac-turers are now implementing various strategies tocontrol dose. One such strategy is to use prepro-grammed technique factors which manufacturers arecurrently fine tuning to specific patient sizes, particu-larly for pediatrics. Because tube current directly af-fects the patient dose and the image quality,manufacturers are working on methods to control tubecurrent during the exposure. One method varies thetube current based on the scout view. At least one scout
view is normally collected before a scan begins and isacquired by fixing the x-ray tube while moving thepatient through the scanner. From the scout view, it ispossible to calculate the tube current needed for eachslice. The simplest dose-control system uses just onescout view, although some can make use of two views.
A more advanced dose-control method uses real-time information about the patient’s anatomy derivedfrom the beam signal received by the detectors as thescan is progressing. Obtaining such feedback informa-tion is possible because of the faster electronics ontoday’s CT scanners. The user sets the desired imagequality level, and the scanner adjusts the tube currentas needed. Studies with patients suggest that dosesavings up to 50% may be possible using these systems(Greess et al. 2000).
Reported problemsA recent study (Brenner et al. 2001) has reported
increased radiation-induced cancer risk because CT isincreasingly being used for examining pediatric pa-tients. Although the risk/benefit ratio is such that mostCT examinations of children are necessary, one study(Donnelly et al. 2001) found that radiation dose of theexam can be reduced by adjusting the CT protocolbased on patient weight. In particular, the mA andpitch settings were lowered for helical scanning. Somehelical CT units have software that automaticallychooses mA settings for the best image quality for adultimaging. The authors recommend overriding suchautomatic settings when imaging children. Recently,manufacturers have been fine-tuning preprogrammedtechnique factors to specific patient sizes, particularlyfor pediatrics. Dose-control mechanisms are now avail-able on many scanners, and manufacturers are experi-menting with various options to find which is the mostacceptable to users. ECRI will monitor developmentsin this area.
Despite the superior low-contrast resolution that CToffers, the spatial resolution of CT is relatively poorcompared to that of film radiographic techniques. Thislimit on spatial resolution is typically not a majorproblem for most CT applications, but it may presenta problem when attempting to scan thin structures, asin bone-thickness studies (Newman et al. 1998).
Artifacts can arise in CT images from defects in thedata-gathering process or as a result of the physicsinvolved in x-ray imaging. Motion artifacts are commonin images produced from projection data acquired whilethe patient was moving. The filtered back-projectionprocess requires that the structures being imaged re-main stationary during the entire scanning procedure;otherwise, the positive and negative components of the
various projections will not cancel appropriately, re-sulting in linear streaks through the reconstructedimage. The streaks generally originate at high-contrastinterfaces, such as the bony protuberances on the insideof the skull or the interface between bowel gas andcontrast material. Patient cooperation and shortenedscanning time can reduce this type of artifact.
The so-called metal artifact, in which bright streaksradiate from a central high-density metal clip or bulletfragment, is in fact a motion artifact. The extremelyhigh density and small relative size of the metal objectcause severe streaks even with very little motion.These artifacts often cannot be prevented because theycan arise from movement as fine as that caused byblood passing through an artery.
Failure to take enough transmission measurementsduring the scan often results in sampling artifacts thatappear as repetitive high-spatial-frequency patternsradiating from some high-density object. The apparentsource of the artifact may or may not be within theimage reconstruction circle.
Using polychromatic x-ray beams from a standardx-ray tube introduces a potentially serious artifactsource. The preferential absorption of lower-energyphotons (beam hardening) causes a large object toappear less absorptive than a smaller object with thesame attenuation characteristics. In images that areinadequately corrected for this phenomenon, beamhardening causes the CT values obtained for a particu-lar organ to be highly dependent on patient size. Forexample, the CT values for normal liver tissue in aninfant are significantly larger than those for a largeadult when both are imaged in the same system. Asecond effect of this phenomenon is that the thickerportions of a patient’s body appear to be less densethan the thinner portions. If severe enough, beamhardening can interfere with the radiologist’s abilityto make clinical diagnoses.
Beam-hardening artifacts can be partially correctedby proper scanner calibration or by a shaped filter (onewith a bow-tie-shaped cross section) through which thex-ray beam passes on its way to the patient. The x-rayspassing through the shorter absorption paths at theedge of the patient body pass through a thicker portionof the filter, while the beam passing through the thincentral part of the filter then passes through thethicker central part of the patient’s body. The finalresult is that the beam is uniformly hardened, inde-pendent of the shape of the patient’s body.
In helical CT, increased image noise, edge blur-ring, and artifacts can occur. Artifacts related tohelical CT include inhomogeneous patches and halos,
stair-stepping in 3-D images, artifacts resulting fromvolume averaging, and artifacts simulating ascendingaortic dissection. Varying the scan protocol, decreasingtable feed or slice thickness, and changing the timingof contrast medium injection can help reduce the oc-currence of artifacts during helical CT scanning.
Image quality and overall system performanceshould be monitored through a comprehensive qualitycontrol program that includes measurements of reso-lution, noise, patient radiation dose, and the accuracyof CT numbers. Patient couch positioning, image proc-essing, and hard-copy output should also be evaluated.
Contrast medium injection can cause several prob-lems. The most common complication is the formationof blood clots, which can lodge downstream and occludesmaller vessels. Care must be taken to avoid injectingcontrast medium directly into the vessel wall, whichcould cause dissection or occlusion of the vessel. Newcatheter designs have been introduced that reportedlyenable high flow while avoiding turbulence at thecatheter terminus. Several incidents of toxic or ana-phylactic reactions to contrast agents have been re-ported, including minor nausea and vomiting, skinrashes, cardiac arrest, bronchospasm, ventricular fib-rillation, and renal insufficiency. The American Col-lege of Radiology and the American College ofCardiology have recently recommended the use ofnewer nonionic or low-osmolality agents in certainpatients who are at a higher risk of suffering adversereactions. Hospitals should implement a policy govern-ing use of high-osmolality versus low-osmolality andnonionic contrast agents. In addition, thrombus forma-tion is possible when blood mixes with nonionic con-trast medium in an injection syringe or catheter.
Purchase considerationsECRI Recommendations
Included in the accompanying comparison chart areECRI’s recommendations for minimum performancerequirements for CT scanners; recommended specifi-cations have been categorized into three groups — low,mid, and high. The low-range category specifies asingle-slice scanner; the mid- and high-range recom-mendations are for multislice scanners. Other differ-entiating criteria include the types of exams that canbe performed and the patient throughput possible.
Most routine exams can be adequately performedusing a single-slice system; however, scan times mightbe somewhat longer since only one slice is acquired inone rotation of the x-ray tube. Multislice systems ac-quire more and thinner slices in one rotation, allowingfor more complex exams (e.g., cardiac) and more varied
patient populations (e.g., pediatric, trauma). However,as the number of slices that can be acquired increases,the incremental benefit actually decreases. For exam-ple, the smallest slice width on a 4-slice scanner is thesame as that on a 16-slice scanner. In addition, mostexams do not require the smallest slice width. Indeed,for slices wider than 5 mm, there is absolutely nodifference between 4-slice and 16-slice systems.
Another important, though more subtle, differenceis the speed of image reconstruction. Acquiring moreslices is of little benefit if patient throughput is held upby slow image reconstruction. Conversely, there islittle point purchasing a very high specification com-puter that will rarely be used to capacity. The same istrue for the x-ray generator and tube. Low volumefacilities will see little benefit from the more efficientuse of the x-ray tube on a 16-slice scanner to warrantits over $100,000 replacement cost. Therefore, beforebuying a CT system it is necessary to evaluate patientpopulation, clinical needs, and desired throughput.
Other considerations
A number of design features must be consideredbefore purchasing a CT scanner. Comparable scannersfrom various manufacturers differ little in their basicclinical applications. The principal differences be-tween top-of-the-line and less sophisticated modelsgenerally involve cycle time (scanning and reconstruc-tion time), spatial resolution, data storage features,and helical scanning protocols. Any CT scanner modelbeing considered for purchase must be examined whileit is operating (preferably in a clinical setting ratherthan in a manufacturer’s demonstration room).
Distributed processing in the construction of CTscanners has eliminated the need for specially air-conditioned computer rooms in some cases, but suchrooms are generally still required. Failure to provideadequate air-conditioning for the computer equipmentseverely compromises the reliability of the scannersystem and ultimately shortens its useful life. In mostcases, the existing hospital air-conditioning systemcannot be used because its operation is tied to outdoorweather conditions, and many times it is already oper-ating close to capacity. Conditioning the electricalpower supply is also required because the ability of thescanner to make artifact-free images often dependsstrongly on the electrical power energizing the instru-ment. Surge suppressors and means for automaticdisconnection in the event of power failure should alsobe installed.
The length of time required to install the scannervaries with the supplier but may range from one week
to two months. Installation times of two weeks arecommon.
The complexity of CT scanners makes adequatetraining an absolute necessity. However, technicianand physician training varies with the supplier. Theusual training consists of one or more visits to thefacility by an instructor provided by the supplier. Mostinitial training periods are three to four days, butlonger visits are often desirable, depending on thein-house expertise and experience. Follow-up visitsshould be arranged three to six months after the initialinstallation.
Cost containment
Before purchasing a CT scanner, buyers should con-sider the facility’s current patient volume and thenumber and types of procedures performed. For in-stance, if the facility expects to perform a large numberof CTA studies or expects to scan a large number ofpediatric, geriatric, and trauma patients, it shouldconsider purchasing a slip-ring CT scanner with multi-slice capabilities and an x-ray tube with a high heatstorage capacity (3,500,000 heat units [HU] orgreater).
Because CT scanners entail ongoing maintenanceand operational costs, the initial acquisition cost doesnot accurately reflect the total cost of ownership. Apurchase decision should be based on issues such aslife-cycle cost (LCC), local service support, discountrates and non-price-related benefits offered by thesupplier, and standardization with existing equipmentin the department or hospital (i.e., purchasing all ra-diographic equipment from one supplier).
An LCC analysis can be used to compare alterna-tives and/or to determine the positive or negative eco-nomic value of a single alternative. For example,hospitals can use LCC analysis techniques to examinethe cost-effectiveness of leasing or renting equipmentversus purchasing the equipment outright. Because itexamines the cash-flow impact of initial acquisitioncosts and operating costs over a period of time, LCCanalysis is most useful for comparing alternatives withdifferent cash flows and for revealing the total costs ofequipment ownership. One LCC technique — presentvalue (PV) analysis — is especially useful because itaccounts for inflation and for the time value of money(i.e., money received today is worth more than moneyreceived at a later date). Conducting a PV/LCC analy-sis often demonstrates that the cost of ownership in-cludes more than just the initial acquisition cost andthat a small increase in initial acquisition cost mayproduce significant savings in long-term operatingcosts. The PV is calculated using the annual cash
outflow, the dollar discount factor (the cost of capital),and the lifetime of the equipment (in years) in a mathe-matical equation.
The following represents a sample five-year PV/LCCanalysis for a CT scanner with helical capability.
Present Value/Life-Cycle Cost Analysis
Assumptions
• Operating costs are considered for years 1 through 5
• Dollar discount factor is 5.8%
• Inflation rate is 6% for a full-service contract and4% for disposables (e.g., contrast media, film)
• Operating and ownership costs are for one CT scan-ner operating two shifts per day Monday throughFriday and one shift Saturday, with 15 scans pershift
• Nonionic contrast medium is used for three scansper shift, at a cost of $125 per dose (ionic contrastmedium is less expensive)
• 75 films per shift, at a cost of $1.50 per sheet, aregenerated
• Costs for two full-time CT technologists includesalary, benefits, payroll expenses, and continuingeducation
Capital Costs
• 4-slice, slip-ring CT system with helical scanning =$1,200,000
Total Capital Costs = $1,200,000
Operating and Ownership Costs
• Service contract, including x-ray tube, years 2through 5 = $135,000/year
• Salary and expenses for two FTEs = $110,000/year
• Contrast media = $214,500/year
• Film = $64,400/year
Total Operating Costs = $388,900 for year 1;$523,900/year for years 2 through 5
PV = ($3,643,022)
Other costs not included in the above analysis thatshould be considered for budgetary planning includethose associated with the following:
• Networking or interfacing the CT system to otherdevices such as laser imagers or workstations
• Film processing costs such as for chemicals or filmhandlers
• Optional software packages such as for dentalCT, bone mineral analysis, and CT radiotherapysimulation
• Hardware and software upgrades not covered underthe warranty or service contract
• Utilities
• Disposables and accessories related to certainprocedures
• Contributions to overhead
As illustrated by the above sample PV/LCC analy-sis, the initial acquisition cost is only a fraction of thetotal cost of operation over five years. Therefore, beforemaking a purchase decision based solely on the acqui-sition cost of a CT scanner, buyers should consideroperating costs over the lifetime of the equipment.
For further information on PV/LCC analysis, cus-tomized analyses, and purchase decision support,readers should contact ECRI’s SELECT™ Group.
The above analysis considers film costs associatedwith printing hard copies on a laser imager. Film costsmay be reduced by purchasing radiologist worksta-tions that allow on-screen image review and diagnosis.
Hospitals can purchase service contracts or serviceon a time-and-materials basis from the supplier. Ser-vice may also be available from a third-party organiza-tion. The decision to purchase a service contract shouldbe carefully considered. Most suppliers provide routinesoftware updates, which enhance the scanner’s per-formance, at no charge to service contract customers.Furthermore, software updates are often cumulative;that is, previous software revisions may be required inorder to install and operate a new performance feature.Purchasing a service contract also ensures that pre-ventive maintenance will be performed at regular in-tervals, eliminating the possibility of unexpectedmaintenance costs. Also, many suppliers do not extendsystem performance and uptime guarantees beyondthe length of the warranty unless the system is coveredby a service contract. Although the solid-state electron-ics of modern medical instrumentation are very reli-able, the complexity of CT scanners makes itimperative that effective service capability be demon-strated by any CT supplier under consideration. Serv-ice must be available without significant delay toensure cost-effective use of the scanner.
ECRI recommends that, to maximize bargainingleverage, hospitals negotiate pricing for service con-tracts before the system is purchased. As a guideline,full-service contracts without tubes typically cost ap-proximately 7% to 12% of the scanner’s purchase price.Contracts with tubes are higher. Additional service
contract discounts may be negotiable for multiple-yearagreements or for service contracts that are bundledwith contracts on other equipment in the departmentor hospital.
With the current replacement-based CT market,hospitals may receive a significant discount from thelist price. The actual discount received will depend onthe hospital’s negotiating skills, the system configura-tion and model to be purchased, previous experiencewith the supplier, and the extent of concessionsgranted by the supplier, such as extended warranties,fixed prices for annual service contracts, and guaran-teed on-site service response. Buyers should make surethat applications training is included in the purchaseprice of the system. Some suppliers do offer moreextensive on-site or off-site training programs for anadditional cost.
Standardization of equipment can make staff train-ing easier, simplify servicing and parts acquisition,and provide greater bargaining leverage when negoti-ating the purchase of new equipment and/or servicecontract costs.
An alternative to the permanent installation of a CTscanner is the use of a mobile service in which thescanner facility is mounted in a specially modifiedtruck or bus that visits the hospital or clinic on aregularly scheduled basis. Many small hospitals arefinding this to be a workable alternative to the largefinancial commitment involved in a permanent instal-lation. Properly designed mobile systems are as reli-able as permanent systems and offer the advantage ofrelieving the hospital administration of the ongoingconcerns of scanner and facility maintenance. Further,mobile services are usually used on a fee-for-servicebasis, and instituting a CT clinical service on this basisis more easily justified to the local healthcare regula-tory organization. In addition, leasing for more expen-sive, high-performance systems is becoming morecommon. For additional information see the HealthDevices evaluation May 2002 citation listed below.
Stage of developmentAlthough CT is now considered to be a mature
technology (the first scanner for imaging the head wasintroduced in 1972), multislice technology introducedin 1998 is a significant development, shortening scan-ning times, improving image quality, expanding theapplications of helical CT (particularly for CTA), in-creasing x-ray tube efficiency, and enabling 3-D imagereconstructions. Several manufacturers offer 4-slicescanning systems, and some manufacturers offer 8-slice and 16-slice systems. Also, some manufacturersstate that their scanners — including single-slice
models — are being designed with future hardwareupgrades in mind. As more slices are added, the work-station and PACS will also need to be upgraded tohandle the increased data volume; therefore, it is notjust the detector that will need to be changed as thistechnology develops.
Some systems now offer cardiac gating as well. CTfluoroscopy, which allows for real-time image acquisi-tion and display during interventional procedures, isavailable with some systems. As CT scanners becomemore widely used for real-time imaging during inter-ventional procedures, CT fluoroscopy will likely be-come more widely available.
Manufacturers are also offering systems which per-form image overlay. The CT image is combined with amagnetic resonance image, a PET image, or an imageof another radiographic modality of the same area. Byusing software to combine these images in an overlay(image fusion), physiologic and anatomic conditions inthe area of interest may be enhanced. Details notrecognized by one modality may be registered by theother.
Combined PET/CT systems are currently availablethat acquire both images without moving the patient.Combined PET/CT systems attempt to minimize mis-alignment in the fusion of two images which may differsignificantly due to the patient having been scannedon separate PET and CT systems at different times.Combined PET/CT systems are primarily intended foroncologic imaging, in particular to enhance treatmentplanning for radiotherapy or surgery, because theyprovide both anatomic and functional information.This capability also makes combined PET/CT usefulfor cardiac imaging. During a PET/CT imaging proce-dure, the CT image is acquired first, then the PET scanis performed. The patient remains on the same imag-ing table throughout the procedure, which takes about30 minutes not including the radiopharmaceutical up-take time of approximately one hour (the radiophar-maceutical is injected before the CT scan is performed).For PET scanning system specifications, see theHealthcare Product Comparison System report titledSCANNING SYSTEMS, POSITRON EMISSION TO-MOGRAPHY.
Bibliography
Baumgart D, Schmermund A, Goerge G, et al. Com-parison of electron beam computed tomographywith intracoronary ultrasound and coronary angiog-raphy for detection of coronary atherosclerosis. JAm Coll Cardiol 1997 Jul;30(1):57-64.
Bluemke DA, Chambers TP. Spiral CT angiography: analternative to conventional angiography. Radiology1995 May;195(2):317-9.
Bonk RT. Helical CT: principles and current applica-tions. Appl Radiol 1997 Mar;(Suppl):59-62.
Brenner DJ, Elliston CD, Hall EJ, et al. Estimatedrisks of radiation-induced fatal cancer from pediat-ric CT. AJR Am J Roentgenol 2001 Feb;176(2):289-96.
Broderick LS, Shemesh J, Wilensky RL, et al. Mea-surement of coronary artery calcium with dual-slicehelical CT compared with coronary angiography:evaluation of CT scoring methods, interobservervariations, and reproducibility. AJR Am JRoentgenol 1996 Aug;167(2):439-44.
Bushberg JT, Seibert JA, Leidholdt EM Jr, et al. Theessential physics of medical imaging. Baltimore:Williams & Wilkins; 1994.
Casey B. Computed tomography [article online]. Diag-nostic Imaging Webcast [cited 1999 Apr 1]. Avail-able from Internet: http://www.dimag.com/webcast/wc_story3.htm.
Curry TS 3rd, Dowdey JE, Murry RC Jr. Christensen’sphysics of diagnostic radiology. 4th ed. Philadel-phia: Lea & Febiger; 1990.
Dellaria MF. Future contrast media for computed to-mography. Appl Radiol 1996 Mar;(Suppl):47-50.
Donnelly LF, Emery KH, Brody AS, et al. Minimizingradiation dose for pediatric body applications ofsingle-detector helical CT: strategies at a large chil-dren’s hospital [perspective]. AJR Am J Roentgenol2001 Feb;176(2):303-6.
Ernst RD, Kim HS, Kawashima A, et al. Near real-time CT fluoroscopy using computer automatedscan technology in nonvascular interventionalprocedures. AJR Am J Roentgenol 2000 Feb;174(2):319-21.
Gay SB, Matthews AB. Computed tomography: tenreasons why helical CT is worth a million bucks.Diagn Imaging 1998 Nov:111-4.
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Guerci AD, Spadaro LA, Popma JJ, et al. Relation ofcoronary calcium score by electron beam computedtomography to arteriographic findings in asympto-matic and symptomatic adults. Am J Cardiol 1997Jan 15;79(2):128-33.
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Kalender WA, Seissler W, Klotz E, et al. Helical volu-metric CT with single-breath-hold technique, con-tinuous transport, and continuous scanner rotation.Radiology 1990 Jul;176(1):181-3.
Klinke G. Helical CT: advantages and artifacts. ApplRadiol 1996 Mar;(Suppl):17-9.
Kobayashi Y, Nonogi H, Toyofuku M, et al. Coronaryartery aneurysms detected with ultrafast computedtomography. Cathet Cardiovasc Diagn 1997 Nov;42(3):302-4.
McCunn M, Mirvis S, Reynolds HN, et al. Physicianutilization of a portable computed tomography scan-ner in the intensive care unit. Crit Care Med 2000Dec;28(12):3808-13.
Miller RL. The challenges of pediatric helical CT. ApplRadiol 1997 Mar;(Suppl):55-8.
Morgan CL, Morgan PM. Basic principles of computedtomography. Baltimore: University Park Press;1983.
Newman DL, Dougherty G, al Obaid A, et al. Limita-tions of clinical CT in assessing cortical thicknessand density. Phys Med Biol 1998 Mar;43(3):619-26.
Ogilvy CS, Lustrin ES, Brown JH. Computerized to-mographic angiography (CTA) assists in the evalu-ation of patients with intracranial aneurysms[article online]. [cited 1999 April 1]. Available fromInternet: http://neurosurgery.mgh.harvard.edu/v-f-94-1.htm.
Orames C. The efficiency of technology: can real-timeCT scanners reduce interventional procedure times?Radiographer 2000 Aug;47(2):67-8.
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Zickler P. Computed tomography: the current spin onhelical. Med Imaging 1996 Mar;11(3):47-9.
Standards and guidelinesNote: Although every effort is made to ensure that thefollowing list is comprehensive, please note that otherapplicable standards may exist.
American Association of Physicists in Medicine. Speci-fication and acceptance testing of computed to-mography scanners [report]. Diagnostic X-RayCommittee Task Group #2. 1993.
American College of Cardiology/American Heart Asso-ciation. Expert consensus document on electron-beam computed tomography for the diagnosis andprognosis of coronary artery disease. J Am CollCardiol 2000 Jul;36(1):326-40.
American College of Radiology. Computed tomography[policy statement]. 1980 (reaffirmed 1990).
MR and CT reimbursement [policy statement]. 1986(revised 1996).
Standard for diagnostic medical physics perform-ance monitoring of computed tomography equip-ment. 1998.
American National Standards Institute/Associationfor the Advancement of Medical Instrumentation.Safe current limits for electromedical apparatus
American Society for Testing and Materials. Guide forcomputed radiography. BSR/ASTM E2007-99.1998.
American Society of Radiologic Technologists. Radi-ologic technologists in radiologic sciences perform-ing computed tomography technology [positionstatement]. 1994 (revised 1998).
Blue Cross and Blue Shield Association. Electronbeam computed tomography; clinical and cost- ef-fectiveness analyses. 1998.
Canadian Coordinating Office for Health TechnologyAssessment. Comparison of fixed and mobile CT andMRI scanners [technology assessment report]. 1995.
Committee for Evaluation and Diffusion of InnovativeTechnologies. Low-end CT scanners. 1997.
Environmental Health Directorate. Safety code 31:radiation protection in computed tomography in-stallations. H46-2/94-181E. 1994.
International Electrotechnical Commission. Evalu-ation and routine testing in medical imaging depart-ments — part 2-6: constancy tests — x-rayequipment for computed tomography [standard].IEC 61223-2-6 (1994-04). 1994.
Medical electrical equipment — part 1: general re-quirements for safety [standard]. IEC 60601-1(1988-12). 1988.
Medical electrical equipment — part 1: general re-quirements for safety. Amendment 1 [standard].IEC 60601-1-am1 (1991-11). 1991.
Medical electrical equipment — part 1: general re-quirements for safety. Amendment 2 [standard].IEC 60601-1-am2 (1995-03). 1995.
Medical electrical equipment — part 1: general re-quirements for safety. Section 1. Collateral stan-dard: safety requirements for medical electricalsystems. IEC 60601-1-1 (1992-06). 1992.
Medical electrical equipment — part 1: general re-quirements for safety. Section 1. Collateral stan-dard: safety requirements for medical electricalsystems. Amendment 1 [standard]. IEC 60601-1-1-am1 (1995-11). 1995.
Medical electrical equipment — part 1: general re-quirements for safety. Section 2. Collateral stan-dard: electromagnetic compatibility — requirementsand tests. IEC 60601-1-2 (2001-09). 2001.
Medical electrical equipment — part 2-44: particu-lar requirements for the safety of x-ray equipment
for computed tomography. IEC 60601-2-44 (2001-06). 2001.
Royal Australian and New Zealand College of Radiolo-gists. Guidelines for operation of CT scanners. 1998June.
Royal College of Radiologists. Use of computed to-mography in the initial investigation of commonmalignancies [report]. 1995.
U.S. Department of Health and Human Services. Foodand Drug Administration. Computed tomography(CT) equipment. 21 CFR Part 1020.33. 2001.
Performance standards for ionizing radiation emit-ting products. 21 CFR Part 1020. 2001.
Citations from other ECRI publicationsHealth Devices
In-house servicing of x-ray and CT equipment [guid-ance article]. 1992 Jun-Jul;21(6-7):231-47.
Artifacts and the need for proper head centering onPicker PQ 2000 computed tomography (CT) scan-ners [User Experience Network™]. 1996 Feb-Mar;25(2-3):109.
Quality control phantom for computed tomography(CT) scanners [Talk to the specialist]. 1997 Mar;26(3):124.
GE HiSpeed Advantage computed tomography scan-ner [evaluation]. 1997 Dec;26(12):457-70.
Unnecessary initiation of warm-up routine on GEProSpeed CT scanners [User Experience Net-work™]. 1998 Mar;27(3):118-9.
Inadequate warnings on a GE CT/i (Octane) CT scan-ner may delay diagnosis [hazard report]. 2001 Apr;30(4):149-50.
Longevity of x-ray tubes in multislice CT scanners[Talk to the specialist]. 2001 Jun;30(6):231.
Eye on medical errors: dose control in computed to-mography — automated systems are now available.2002 May;31(5):164.
Money matters: X-ray tube life in multislice CT scan-ners. 2002 May;31(5):166.
Multislice computed tomography systems [evalu-ation]. 2002 May;31(5):161-88.
Health Devices Alerts
This Product Comparison lists Health Devices Alerts(HDA) citations published since the last update of thisreport. Each HDA abstract is identified by an Accession
Number. Recalls and hazard reports include descrip-tions of the problem involved; abstracts of other pub-lished articles are referenced by bibliographicinformation. HPCS subscribers can call the Hotline foradditional information on any of these citations or torequest more extensive searches of the HDA database.
A4535 FDA issued a Public Health Notification warn-ing healthcare workers of the radiation overdose risksto pediatric and small adult patients during computedtomography (CT) procedures. FDA states that thebenefits of CT scanning far outweigh the risks associ-ated with the procedure but cautions that unnecessaryradiation exposure should be avoided. Unnecessarydoses of radiation can occur during CT scans of childrenor small adults when CT scanner parameters are notappropriately adjusted for patient size. FDA statesthat the odds that children will develop cancer fromx-ray radiation are significantly higher than those foradults because children have rapidly dividing cells anda longer life expectancy. FDA recommends severalmeasures to protect children and other small patientsfrom unnecessary radiation exposure during CT proce-dures and encourages reporting of CT equipment mal-functions to the device manufacturer and to FDA’svoluntary reporting program, MedWatch, online athttp://www.accessdata.fda.gov/scrips/medwatch, bytelephone at (800) FDA-1088, by fax at (800) FDA-0178,or by mail at MedWatch, Food and Drug Administra-tion, HF-2, 5600 Fishers Ln, Rockville, MD 20857. Formore information about CT scanners and radiationoverdose, contact Marian Kroen, FDA, by mail at theOffice of Surveillance and Biometrics (HFZ-510), 1350Piccard Dr, Rockville, MD 20850; by fax at (301) 594-2968; by e-mail at [email protected]; or by voice mailat (301) 594-0650. Source: U.S. Food and Drug Ad-ministration. FDA public health notification: reducingradiation risk from computed tomography for pediatricand small adult patients. 2001 Nov 2.
38874 Hirai T, Korogi Y, Ono K, et al. Preoperativeevaluation of intracranial aneurysms: usefulness ofintraarterial 3D CT angiography and conventionalangiography with a combined unit — initial experi-ence. Radiology 2001 Aug;220(2):499-505.
38944 Dougherty G. A comparison of the texture ofcomputed tomography and projection radiography im-ages of vertebral trabecular bone using fractal signa-ture and lacunarity. Med Eng Phys 2001 Aug;23(5):313-21.
39134 Raggi P. The use of electron-beam computedtomography as a tool for primary prevention. Am JCardiol 2001 Oct 11;88(7B):28J-32J.
Health Technology Trends
Virtual reality applied to colonoscopy and broncho-scopy. 1995 Jan;7(1):3.
Ultrafast CT gets cautious nod from heart association.1996 Oct;8(10):8-9.
New CT technique may reduce unnecessary appendec-tomies. 1997 Feb;9(2):8-9.
Healthcare Risk Control
Technology overview. 1996;4:Radiology:3.
Supplier information
GE Imatron
GE Imatron IncDiv GE Medical Systems [402588]389 Oyster Point BlvdSouth San Francisco CA 94080-1913Phone: (650) 583-9964, (800) 367-6545Fax: (650) 871-0418E-mail: [email protected]: http://www.geimatron.com
GE Medical Systems Europe [171319]283 rue de la Miniereboite postale 34F-78533 Buc CedexFrancePhone: 33 (1) 30704040Fax: 33 (1) 30709855E-mail: [email protected]: http://www.gemedicalsystems.com
GE Yokogawa Medical Systems Ltd [183063]4-7-127 AsahigaokaHino-shiTokyo 191JapanPhone: 81 (4) 2525853188E-mail: [email protected]: http://www.gemedical.co.jp
GE Medical
GE Medical Systems [102107]PO Box 414Milwaukee WI 53201-0414Phone: (262) 544-3011, (800) 643-6439Fax: (262) 544-3384Internet: http://www.gemedicalsystems.com
GE Medical Systems Europe [171319]283 rue de la Miniereboite postale 34F-78533 Buc CedexFrancePhone: 33 (1) 30704040Fax: 33 (1) 30709855E-mail: [email protected]: http://www.gemedicalsystems.com
GE South Africa Medical Systems [340559]Private Bag X124Halfway House 1685South AfricaPhone: 27 (11) 3156625
GE Yokogawa Medical Systems Ltd [183063]4-7-127 AsahigaokaHino-shiTokyo 191JapanPhone: 81 (4) 2525853188Internet: http://www.gemedical.co.jp
Philips Medical
Philips Medical Systems Asia [188101]16/Fl Hopewell Centre 17 Kennedy RoadPO Box 2108Hong KongHong Kong SARPeople’s Republic of ChinaPhone: 852 28215364Fax: 852 25276726E-mail: [email protected]: http://www.medical.philips.com
Philips Medical Systems International bv[152365]Global Information SystemsI.B.R.S./C.C.R.I. Numero 11088NL-5600 PB EindhovenThe NetherlandsPhone: 31 (40) 2782559Fax: 31 (40) 2764887E-mail: [email protected]: http://www.medical.philips.com
Philips Medical Systems North America [102120]22100 Bothell Everett HwyPO Box 3003Bothell WA 98041-3003Phone: (425) 487-7000, (800) 526-4963Fax: (425) 485-6080E-mail: [email protected]: http://www.medical.philips.com
Shimadzu
Shimadzu (Asia Pacific) PTE Ltd [172209]16 Science Park Dr #01-02 The PasteurSingapore Science ParkSingapore 118227Republic of SingaporePhone: 65 7786280Fax: 65 7792935E-mail: [email protected]: http://www.shimadzuasiapac.com.sg
Shimadzu Corp Medical SystemsInternational Marketing Div [153971]3 Kanda-Nishikicho 1-chomeChiyoda-kuTokyo 101-8448JapanPhone: 81 (3) 32195641E-mail: [email protected]: http://www.shimadzu.co.jp
Shimadzu Medical Systems [106973]20101 S Vermont AveTorrance CA 90502-3130Phone: (310) 217-8855, (800) 228-1429Fax: (310) 217-0661E-mail: [email protected]: http://www.shimadzumed.com
Siemens Medical Solutions USA Inc [399199]186 Wood Ave SIselin NJ 08830-2704Phone: (732) 321-4500Fax: (732) 321-4780E-mail: [email protected]: http://www.siemensmedical.com
Siemens SA de CV [339105]Poniente 116 No 59002300 Cd de MexicoDistrito FederalMexicoPhone: 52 (5) 3282000Fax: 52 (5) 3282017Internet: http://www.siemens.de
Toshiba
Toshiba America Medical Systems Inc [101894]2441 Michelle DrPO Box 2068Tustin CA 92680-7047Phone: (714) 730-5000, (800) 421-1968Fax: (714) 832-2570E-mail: [email protected]: http://www.medical.toshiba.com
Toshiba Medical Systems Co Ltd [139511]3-26-5 HongoBunkyo-kuTokyo 113-0033JapanPhone: 81 (3) 38182061Fax: 81 (3) 38157215Internet: http://www.medical.toshiba.com
Toshiba Medical Systems Europe bv [160817]Zilverstraat 1NL-2718 RP ZoetermeerThe NetherlandsPhone: 31 (79) 3689222Fax: 31 (79) 3689444Internet: http://www.medical.toshiba.com
Toshiba Medical Systems Singapore [307328]211 Henderson Rd #08-02Henderson Industrial ParkSingapore 159552Republic of SingaporePhone: 65 2729766Fax: 65 2726083
About the chart specificationsThe following terms are used in the chart:
Slice thickness, mm: The width (in millimeters) of thex-ray beam that passes through the patient. Imageresolution and patient dose are affected by slice
thickness. Smaller slices provide greater spatialresolution but require a larger radiation dose.
Gantry tilt, °: The gantry, which holds the x-ray tube,detectors, collimators, rotation motors, and posi-tioning aids, can be tilted from the vertical to facili-tate angulation of the slice without moving thepatient. With sufficient gantry tilt (about 20°), di-rect coronal scans of the head are possible.
Gantry aperture, cm: The gantry aperture is the open-ing in the scanner gantry in which the portion of thepatient anatomy to be scanned is placed.
X-ray tube anode, heat storage, HU: The capacity of thex-ray tube anode to store heat generated during itsoperation, expressed in heat units. In certain typesof studies in which high mA levels are used andmany thin slices are required (e.g., spine studies),the heat storage capacity of the anode can be alimiting factor in the time between scans.
X-ray tube anode, heat dissipation rate, HU/min: Therate at which the anode cools, measured in heatunits/minute. Higher rates of cooling are requiredto accommodate the high heat loads generated dur-ing rapid multiple-slice acquisition (e.g., volumetricscanning).
Pitch: The speed of table motion (in mm/sec) dividedby the x-ray beam collimation width; when the tablespeed and the collimation are equal for a one-secondscan time, the pitch is 1. A pitch greater than 1 isused to scan a larger area in one helical scan duringa single patient breathhold.
Range of movement, longitudinal, cm: Longitudinal ad-justment of the patient table should be sufficient toallow the positioning of any portion of the patient’sbody in the center of the gantry aperture.
Scannable range, cm: The maximum length that canbe scanned without having to move the patientduring the examination.
Scan FOVs, cm: Selecting a smaller scan field of view(FOV) for image reconstruction allows an increasein the spatial resolution of the scan. This entailsusing the minimum acceptable scan field diameterrequired by the anatomic section being scanned.
Reconstruction time, per slice, sec: The interval of timeduring which the computer and associated arrayprocessors transform the raw data into a recon-structed image. The reconstruction time for a singleslice is a small fraction of the throughput time, butwhen multiple slices (10 to 20) are required, the timecan significantly affect patient throughput.
Reconstruction time, for localization scan, sec: The timerequired to process new data taken during scanlocalization radiographs.
Matrixes, pixels: The matrix refers to the number ofpixels (picture elements) in the display. Each pixelhas a fixed density level in the resultant image. Thelarger the matrix, the more pixels and the greaterthe possible resolution, depending on the scan fieldof view.
Range of CT numbers: Density coefficients reflect theactual tissue density of the area of anatomy repre-sented by each pixel. By convention, water is as-signed a CT number of zero. Higher CT numbersreflect greater tissue density.
Hard disk, GB: Online image storage is a function of diskdrive capacity (given in megabytes). A large amountof online storage space eliminates the need to movepatient images to archival storage immediately.
Dynamic scan rate: The high quality and quantitativenature of CT images have led to the development ofdynamic scanning techniques. This application usesscanning times of about one second per image tomonitor the flow of contrast media through thevascular structure of the organ being examined. Toobtain even shorter imaging times, the completescan is divided into overlapping 240° segments. Theattenuation data from these angular segments isthen used to construct tomographic images.
High-contrast spatial resolution: A measure of the re-solving power of the system for objects with a con-trast difference greater than 10% (e.g., bone, softtissue). Resolution is related to the modulationtransfer function (MTF), a curve describing the sys-tem’s ability to reproduce an image. The measure-ment is expressed in line pairs per centimeter (lp/cm)or millimeters (mm) at 0% and 50% MTF to definethe MTF curve for a particular system. Higher num-bers indicate better resolution.
Low-contrast resolution, mm at % at ≤4 rads: A measureof the ability of the system to resolve objects with asmall difference in density. It is generally measuredfrom a contrast-detail curve, which plots the mini-mum contrast detectable at various diameters ofdetail.
DICOM 3.0 interface: American College of Radiol-ogy/National Electrical Manufacturers AssociationDigital Imaging and Communications in Medicinestandard; systems with this interface capabilitymay, under certain conditions, be networked withother devices meeting the standard, regardless ofthe brand or image format.
Abbreviations:
ARO — After receipt of order
CD-R — Recordable compact disc
CE mark — Conformite Europeene mark
CPU — Central processing unit
CSA — Canadian Standards Association
CT — Computed tomography
DEKRA — Institut fuer Sicherheit, Umweltschutzund Energie (Institute for Health, Environ-mental Protection, and Energy)
ECG — Electrocardiogram
EN — European Norm
ETL — ETL Testing Laboratories
FDA — U.S. Food and Drug Administration
FOV — Field of view
GB — Gigabyte
HU — Heat unit
IEC — International Electrotechnical Commission
ISO — International Organization for Standardi-zation
JIS — Japanese Industrial Standards
mA — Milliamps
MB — Megabyte
MDD — Medical Devices Directive
MIP — Maximum intensity projection
MOD — Magneto-optical disk
MPR — Multiplanar reconstruction; a user-interac-tive image manipulation function that reformatsaxial scan data to display coronal, sagittal, andother views of the patient
MR — Magnetic resonance
MTF — Modulation transfer function
RISC — Reduced instruction set computer
TUV — Technischer Ueberwachungs Verein
Note: The data in the charts derive from suppli-ers’ specifications and have not been verified throughindependent testing by ECRI or any other agency.Because test methods vary, different products’
specifications are not always comparable. Moreover,products and specifications are subject to frequentchanges. ECRI is not responsible for the quality orvalidity of the information presented or for any adverseconsequences of acting on such information.
When reading the charts, keep in mind that, unlessotherwise noted, the list price does not reflect supplierdiscounts. And although we try to indicate whichfeatures and characteristics are standard and whichare not, some may be optional, at additional cost.
For those models whose prices were supplied to usin currencies other than U.S. dollars, we have alsolisted the conversion to U.S. dollars to facilitate com-parison among models. However, keep in mind thatexchange rates change often.
Need to know more?For further information about the contents of this
Product Comparison, contact the HPCS Hotline at +1(610) 825-6000, ext. 5265; +1 (610) 834-1275 (fax); [email protected] (e-mail).
About ECRI . . .ECRI is a nonprofit health services research agency and a Collaborating Center of the World HealthOrganization, providing information and technical assistance to the healthcare community to supportsafe and cost-effective patient care for more than 25 years. The results of ECRI’s research andexperience are available through its publications, information systems, databases, technical assis-tance program, laboratory services, seminars, and fellowships.
Our full-time staff includes a wide range of specialists in healthcare technology, hospital admini-stration, financial analysis, risk management, and information and computer science, as well ashospital planners, attorneys, physicists; biomedical, electrical, electronic, chemical, mechanical, andregistered engineers; physicians; basic medical scientists; epidemiologists and biostatisticians; andwriters, editors, and communications specialists.
Underlying ECRI’s knowledge base in healthcare technology are its integrity and objectivity. ECRIaccepts no financial support from medical product manufacturers, and no employee may own stockin or consult for a medical equipment or pharmaceutical company.
The scope of ECRI’s resources extends far beyond technology. ECRI keeps healthcare professionals,manufacturers, legal professionals, information specialists, and others aware of the changing trendsin healthcare, healthcare standards and regulations, and the best ways to handle environmental andoccupational health and safety issues. ECRI also advises on management issues related to healthcarecost containment, accreditation, risk management, human resources, quality of care, and othercomplex topics.
ECRI has more than 35 publications, databases, software, and services to fulfill the growing needfor healthcare information and decision support. They focus on three primary areas: healthcaretechnology, healthcare risk and quality management, and healthcare environmental management.
Colons separate data on similar models of a device. This is the first of* These recommendations are the opinions of ECRI's technology experts. ECRI assumes no liability for decisions made based on three pages covering
this data. the above model(s).** 8 without couch motion. These specifications*** Luminescent crystals coupled to silicon photodiodes. continue onto the† Complete scan is 210°. next two pages.†† Table tilts 0-23° and swivels +23° to -23°.
DISPLAYMonitor size 20" 20" 20" 21"Matrixes, pixels 1024 x 1024 1024 x 1024 1024 x 1024 256 x 256, 512 x 512
Range of CT numbers -1,000 to +3,000 -1,000 to +3,000 -1,000 to +3,000 -1,000 to +3,095Image enlargement 10x 10x 10x Up to 10x
Max no. of slicesdisplayed at once 16 16 16 16
IMAGE STORAGEHard disk, GB 100 50 50 4
No. online images 75,000 40,000 40,000 15,000 (256 x 256),3,700 (512 x 512)
Archival storage MOD, CD, DVD MOD, CD, DVD MOD, CD, DVD 2.3 GB MOD
Colons separate data on similar models of a device. This is the second of* These recommendations are the opinions of ECRI's technology experts. ECRI assumes no liability for decisions made based on three pages covering
this data. the above model(s).** Takes data in a series of 210° sweeps. 2 sweeps considered 360° for pitch calculation. These specifications
std configuration $1,900,000System warranty 1 year 1 year 1 year 1 yearX-ray tube warranty 150,000 scan seconds 150,000 scan seconds 150,000 scan seconds Not specifiedDelivery time, ARO 8 weeksTraining w/purchase Yes Yes Yes 8 days on-site
Remote diagnostics Yes Yes Yes YesYear first sold 2001USA installations Not specifiedWorld installations Not specifiedFiscal year January to December
OTHER SPECIFICATIONS Movie and flow mode;cardiac, multi-level, andcontinuous volumescanning; ECGtriggering; cardiacfunction software;perfusion and wallmotion; optional3-D package withworkstation.ISO 9001certification.
Colons separate data on similar models of a device.* These recommendations are the opinions of ECRI's technology experts. ECRI assumes no liability for decisions made based on
Colons separate data on similar models of a device. This is the first ofthree pages coveringthe above model(s).These specificationscontinue onto thenext two pages.
No. online images 9,200 (512 x 512), 12,000 (512 x 512), 20,000 (512 x 512), 20,000 (512 x 512),500 raw data 3,000 raw data 3,000 raw data 3,000 raw data
Colons separate data on similar models of a device. This is the second ofthree pages coveringthe above model(s).These specificationscontinue onto thenext page.
at % at ≤4 rads 3 at 0.3% at 0.9 5 at 0.3% at 0.9 5 at 0.3% at 0.9 5 at 0.3% at 0.9rads; 20 cm CATPHAN rads; 20 cm CATPHAN rads; 8" CATPHAN rads; 8" CATPHAN
Noise,% at ≤2.5 rads 0.35 0.35 0.26 0.26 at 2.41 rads
CORONARY ARTERYCALCIFICATION
SCORING Not specified Not specified Not specified Not specified
DICOM 3.0 INTERFACE Yes Yes Yes Yes
RECOMMENDED ROOMSIZE, m2 13 13 18 18
POWER REQUIREMENTS 460/480 VAC nominal, 460/480 VAC nominal, 460/480 VAC nominal, 460/480 VAC nominal,50/60 Hz, 3-phase 50/60 Hz, 3-phase 50/60 Hz, 3-phase 50/60 Hz, 3-phasedelta or Wye delta or Wye delta or Wye delta or Wye
PLANNING & PURCHASEList price,
std configuration $375,000 Not specified $750,000 $895,000System warranty 1 year, parts/labor 1 year, parts/labor 1 year, parts/labor 1 year, parts/laborX-ray tube warranty 80,000 slices Not specified 1 year prorated 1 year proratedDelivery time, ARO 45 days Not specified 45 days 45 daysTraining w/purchase Not specified Not specified 4 days HQ class 4 days HQ class
Remote diagnostics Yes Yes Yes YesYear first sold 1999 Not specified 2000 2000USA installations >45 Not specified 20 40World installations >600 Not specified 50 90Fiscal year January to December January to December January to December January to December
mA range 10-350 10-250, optional 300 10-440 10-440
Colons separate data on similar models of a device. This is the first ofthree pages coveringthe above model(s).These specificationscontinue onto thenext two pages.
Reconstructionmatrixes 512 x 512 512 x 512 512 x 512 512 x 512
Reconstruction timePer slice, sec 1.5 2 2 0.5
For localizationscan, sec Real time Real time Real time Real time
DISPLAYMonitor size 20" (2) 21" 21" 20" (2)Matrixes, pixels 1280 x 1024 1280 x 1024 1280 x 1024 1280 x 1024
Range of CT numbers -1,024 to +3,071 -32,767 to +32,767 -32,767 to +32,767 -1,024 to +3,071Image enlargement Up to 8x Up to 8x Up to 8x Up to 8x
Max no. of slicesdisplayed at once 16 16 16 16
IMAGE STORAGEHard disk, GB 13.5 9 9 13.5
No. online images 20,000 (512 x 512), 10,000 (512 x 512), 10,000 (512 x 512), 20,000 (512 x 512),2,000 raw data 1,000 raw data 1,000 raw data 2,000 raw data
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POWER REQUIREMENTS 460/480 VAC nominal, 460/480 VAC nominal, 460/480 VAC nominal, 460/480 VAC nominal,50/60 Hz, 3-phase 50/60 Hz, 3-phase 50/60 Hz, 3-phase 50/60 Hz, 3-phasedelta or Wye delta or Wye delta or Wye delta or Wye
PLANNING & PURCHASEList price,
std configuration $1,145,000 $525,000 $765,000 $1,250,000System warranty 1 year, parts/labor 1 year, parts/labor 1 year, parts/labor 1 year, parts/laborX-ray tube warranty 1 year prorated 1 year prorated 1 year prorated 1 year proratedDelivery time, ARO 45 days 45 days 45 days 45 daysTraining w/purchase 4 days HQ class 4 days HQ class 4 days HQ class 4 days HQ class
Remote diagnostics Yes Yes Yes YesYear first sold 1998 1998 1998 2000USA installations >850 300 40 >300World installations >1,100 500 100 >400Fiscal year January to December January to December January to December January to December
mA range 10-440 10-440 10-440 28-500 in 1 mAincrements
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For localizationscan, sec Real time Real time Real time 1-4
DISPLAYMonitor size 20" (2) 20" (2) 20" (2) 21"Matrixes, pixels 1280 x 1024 1280 x 1024 1280 x 1024 1280 x 1024
Range of CT numbers -1,024 to +3,071 -1,024 to +3,071 -1,024 to +3,071 -1,024 to +3,072Image enlargement Up to 8x Up to 8x Up to 8x Up to 10x; real time
Max no. of slicesdisplayed at once 16 16 16 64
IMAGE STORAGEHard disk, GB 13.5 Not specified 13.5 36
No. online images 20,000 (512 x 512), Not specified 20,000 (512 x 512), 65,000 (512 x 512)2,000 raw data 2,000 raw data
POWER REQUIREMENTS 460/480 VAC nominal, 460/480 VAC nominal, 460/480 VAC nominal, 380-480 VAC, 90 kVA,50/60 Hz, 3-phase 50/60 Hz, 3-phase 50/60 Hz, 3-phase 3-phasedelta or Wye delta or Wye delta or Wye
PLANNING & PURCHASEList price,
std configuration $1,145,000 $1,145,000 $1,145,000 Not specifiedSystem warranty 1 year, parts/labor 1 year, parts/labor 1 year, parts/labor 1 yearX-ray tube warranty 1 year prorated 1 year prorated 1 year prorated 150,000 scan secondsDelivery time, ARO 45 days 45 days 45 days 90 daysTraining w/purchase 4 days HQ class 4 days HQ class 4 days HQ class Yes
Remote diagnostics Yes Yes Yes YesYear first sold 1998 1998 1998 2002USA installations >850 >850 >850 Not specifiedWorld installations >1,100 >1,100 >1,100 Not specifiedFiscal year January to December January to December January to December January to December
For localizationscan, sec 1-4 1-4 Real time Real time
DISPLAYMonitor size 21" 21" Dual 21" Dual 21"Matrixes, pixels 1280 x 1024 1280 x 1024 1024 x 1024 1024 x 1024
Range of CT numbers -1,024 to +3,072 -1,024 to +3,072 -2,000 to +4,000 -2,000 to +4,000Image enlargement Up to 10x; real time Up to 10x; real time Up to 9.9x Up to 9.9x
Max no. of slicesdisplayed at once 64 64 25 25
IMAGE STORAGEHard disk, GB 9 9 9.1 9.1 image
No. online images 11,000 (512 x 512) 11,000 (512 x 512) 14,500 (512 x 512) 14,500 (512 x 512)uncompressed
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std configuration Not specified Not specified Not specified Not specifiedSystem warranty 1 year 1 year 1 year 1 yearX-ray tube warranty 150,000 scan seconds 150,000 scan seconds 100,000 exposures * 100,000 slicesDelivery time, ARO 30 days 30 days 3 months 3 monthsTraining w/purchase Yes Yes Yes 56 hours on-site
Remote diagnostics Yes Yes Yes YesYear first sold 1998 2000 1999 1999USA installations Not specified Not specified Not specified Not specifiedWorld installations Not specified Not specified Not specified Not specifiedFiscal year January to December January to December January to December January to December
OTHER SPECIFICATIONS AutoScan; AutoVoice; AutoScan; AutoVoice; 3-D display; 3-D display;AutoFilm; AutoSend; AutoFilm; AutoSend; AutoFilm; AutoVoice; AutoVoice;AutoArchive; AutoArchive; dental formatting; AutoFilming;Bolus Pro Ultra; Bolus Pro Ultra; CT/MR matching; dental formatting;Spiral Auto Start; Spiral Auto Start; bone mineral CT/MR matching;Dynamic Focal Spot; Dynamic Focal Spot; analysis; bone mineralisotropic imaging; isotropic imaging; CT fluoroscopy; analysis;cardiac scoring; cardiac scoring; workstation. Meets workstation. Meetsfunctional CT; functional CT; requirements of CSA requirements of CSAcardiac imaging; cardiac imaging; and ETL. and ETL.ImagePro; Q-BMAP; ImagePro; Q-BMAP;Denta-CT; Master- Denta-CT; Master-Look; optional Pin- Look; optional Pin-Point (integrated Point (integratedstereotactic arm). stereotactic arm).
Colons separate data on similar models of a device.* Guaranteed.
mA range 30-400 in 10 mA 30-400 in 10 mA 50-250; optional 50-250; optionalincrements increments 300, 370 300, 370
Colons separate data on similar models of a device. This is the first ofthree pages coveringthe above model(s).These specificationscontinue onto thenext two pages.
Reconstructionmatrixes 512 x 512 512 x 512 512 x 512 512 x 512
Reconstruction timePer slice, sec 3 3 3-5 2-4
For localizationscan, sec 3-5 3-5 Real time Real time
DISPLAYMonitor size 21" 21" 17" color; opt 21" 21" colorMatrixes, pixels 1152 x 900 1132 x 900 1024 x 1024 1024 x 1024
Range of CT numbers -2,048 to +6,143 -2,048 to +6,143 HU -1,000 to +8,000 -1,000 to +8,000Image enlargement Up to 4x, real time Up to 4x, real time Up to 16x, real time Up to 16x, real time
Max no. of slicesdisplayed at once 4 4 16 16
IMAGE STORAGEHard disk, GB 26 26 12 12
No. online images 11,000 (512 x 512) 11,000 (512 x 512) 8,000 + 3,200 raw 8,000 + 2,200 rawdata data
Archival storage 8 mm cartridge tape; 8 mm cartridge tape, MOD drive MOD driveoptional optical optional opticaldisk disk
Colons separate data on similar models of a device. This is the second of* Scanner includes indexed ACQSIM therapy tabletop. three pages covering
the above model(s).These specificationscontinue onto thenext page.
POWER REQUIREMENTS 480 VAC nominal, 480 VAC nominal, 100/200-480 VAC, 100/200-480 VAC,75 kVA, 3-phase 75 kVA, 3-phase 50/60 Hz, 75 kVA 50/60 Hz, 75 kVA
PLANNING & PURCHASEList price,
std configuration Not specified Not specified $500,000 $675,000System warranty 1 year 1 year 1 year 1 yearX-ray tube warranty 100,000 exposures * 100,000 exposues * 100,000 slices 100,000 slicesDelivery time, ARO 30 days 30 days 60 days 60 daysTraining w/purchase Yes Yes 1 week 1 week
Remote diagnostics Yes Not specified Optional OptionalYear first sold 2001 1998 2001 2000USA installations Not specified Not specified Not specified Not specifiedWorld installations Not specified Not specified Not specified Not specifiedFiscal year January to December January to December January to December January to December
OTHER SPECIFICATIONS Dedicated oncology ImagePro filter; Optical touchpanel Optical touchpanelsystem designed for MSSI; shaded surface user interface; user interface;ease of positioning display; MIP; mouse-driven mouse-drivenfor breast, mantle, 4-D angio volume; Windows-like opera- Windows-like opera-and large patient cardiac scoring; tor environment; tor environment;cases; ImagePro; Polus Pro; PinPoint real-time MPR; user- real-time MPR; user-PinPoint (integrated (integrated recordable auto- recordable auto-stereotactic arm); stereotactic arm); voice; CT fluoro; voice; autolights;optional CT SIM Q-BMAP; continuous virtual endoscopy; laser imager digitalpackage with DRRs, CT (CCT). SMART Enhance; laser interface; softwareDCRs, multimodality imager digital for 3-D display;image fusion, interface; software arbitrary curve MPR;therapy tabletop; for 3-D display; ar- dental CT; optionaloptional 3-D bitrary curve MPR; real-time spiral re-radiation therapy real-time spiral construction and 3-Dtreatment planning. reconstruction and rendering. **
3-D rendering. **
Colons separate data on similar models of a device.* Guaranteed.** Meets requirements of DEKRA, EN 29001 and 46001, ETL, IEC 601-1, ISO 9001, JIS T-1001, JIS Z-9901, and TUV.
Colons separate data on similar models of a device. This is the first ofthree pages coveringthe above model(s).These specificationscontinue onto thenext two pages.
Reconstructionmatrixes 512 x 512 512 x 512 512 x 512 512 x 512
Reconstruction timePer slice, sec 2-4 2-4 6 2 or 1
For localizationscan, sec Real time Real time Real time Real time
DISPLAYMonitor size 21" color 21" color 19" CRT 18" LCD or 21" CRTMatrixes, pixels 1024 x 1024 1024 x 1024 1024 x 1024 max 1024 x 1024 max
Range of CT numbers -1,000 to +8,000 -1,000 to +8,000 -1,024 to +3,071 -1,024 to +3,071 *Image enlargement Up to 16x, real time Up to 16x, real time Yes Yes
Max no. of slicesdisplayed at once 16 16 30 64
IMAGE STORAGEHard disk, GB 12 12 18 18
No. online images 8,000 + 2,200 raw 8,000 + 2,200 raw 30,000 13,000 + 4,000 rawdata data data sets of 2 sec
scans **
Archival storage MOD drive MOD drive CD-R CD-R, MOD
Colons separate data on similar models of a device. This is the second of* Range of CT numbers is -10,240 to +30,710 with extended Hounsfield unit scale. three pages covering** 5,300 raw data sets of 1.5 sec scans. the above model(s).
at % at ≤4 rads 3 at 0.3% 3 at 0.3% 3 at 0.3 at 5 at 0.3 at2.8 rads at 120 mAs 1.99 rads at 90 mAs
Noise,% at ≤2.5 rads 0.33 0.33 Not specified 0.28
CORONARY ARTERYCALCIFICATION
SCORING Not specified Not specified NA NA
DICOM 3.0 INTERFACE Optional Optional Yes Yes
RECOMMENDED ROOMSIZE, m2 18 18 17 17
POWER REQUIREMENTS 100/200-480 VAC, 100/200-480 VAC, 480 VAC, 3-phase, 190-480 VAC,50/60 Hz, 75 kVA 50/60 Hz, 75 kVA ≤17 kVA 3-phase, ≤30 kVA
PLANNING & PURCHASEList price,
std configuration $750,000 $820,000 Not specified Not specifiedSystem warranty 1 year 1 year 1 year 1 yearX-ray tube warranty 100,000 slices 100,000 slices 130,000 scan sec 130,000 scan secDelivery time, ARO 60 days 60 days Not specified Not specifiedTraining w/purchase 1 week 1 week Yes Yes
Remote diagnostics Optional Optional Yes YesYear first sold 2000 2000 2001 2000USA installations Not specified Not specified Not specified Not specifiedWorld installations Not specified Not specified Not specified Not specifiedFiscal year January to December January to December October to September October to September
OTHER SPECIFICATIONS Optical touchpanel Optical touchpanel MPR package; do-it- syngo Osteo; syngouser interface; user interface; yourself service dental; syngo per-mouse-driven mouse-driven capability. fusion; syngo Pulmo;Windows-like opera- Windows-like opera- VRT (Volume Render-tor environment; tor environment; ing Technique); CAREreal-time MPR; user- real-time MPR; user- Dose; syngo Flyrecordable auto- recordable auto- Through; Turbovoice; autolights; voice; CT fluoro; Recon.laser imager digital virtual endoscopy;interface; software SMART Enhance;for 3-D display; laser imager digitalarbitrary curve MPR; interface; softwaredental CT; optional for 3-D display;real-time spiral re- arbitrary curve MPR;construction and 3-D real-time spiral re-rendering. * construction and 3-D
rendering. *
Colons separate data on similar models of a device.* Meets requirements of DEKRA, EN 29001 and 46001, ETL, IEC 601-1, ISO 9001, JIS T-1001, JIS Z-9901, and TUV.
Colons separate data on similar models of a device. This is the first ofthree pages coveringthe above model(s).These specificationscontinue onto thenext two pages.
MODEL SIEMENS MEDICAL SIEMENS MEDICAL SIEMENS MEDICAL SIEMENS MEDICAL
SOMATOM SOMATOM SOMATOM SOMATOMEsprit+ Balance Emotion Emotion Duo
HELICAL SCANNING Yes Yes Yes YesMax scan time, sec 60 80 100 100Max scan volume, cm 120 130 153 153
Spatial resolution,lp/cm 15.5 15.5 15.5 15.5
Pitch 1:1 to 2:1 1:1 to 2:1 1:1 to 2:1 1:1 to 4:1
Reconstruction timeper image, sec 2 or 1 2 or 1 2 or 1 1
PATIENT TABLERange of movement
Vertical, cm 45-83 45-83 45-83 45-83Longitudinal, cm 137 137 160 160
Scannable range, cm 130 130 153 153Max load capacity
with accuracy, kg 200 200 200 200
IMAGE PROCESSINGComputer CPU Multi Intel-based Multi Intel-based Multi Intel-based Multiple Intel-based
servers with Dual servers with Dual servers with Dual servers with DualPentium IV Pentium IV Pentium IV Pentium IV
Scan FOVs, cm 45 50 50 50
Reconstructionmatrixes 512 x 512 512 x 512 512 x 512 512 x 512
Reconstruction timePer slice, sec 2 or 1 2 or 1 2 or 1 1
For localizationscan, sec Real time Real time Real time Real time
DISPLAYMonitor size 18" LCD or 21" CRT 18" LCD or 21" CRT 18" LCD or 21" CRT 18" LCD or 21" CRTMatrixes, pixels 1024 x 1024 max 1024 x 1024 max 1024 x 1024 max 1024 x 1024 max
Range of CT numbers -1,024 to +3,071 * -1,024 to +3,071 * -1,024 to +3,071 * -1,024 to +3,071 *Image enlargement Yes Yes Yes Yes
Max no. of slicesdisplayed at once 64 64 64 64
IMAGE STORAGEHard disk, GB 18 18 18 45
No. online images 13,000 + 2,750 raw 13,000 + 2,750 raw 13,000 + 2,750 or 13,000 + 4,800 ordata sets of 2 sec data sets of 1 sec 3,350 raw data sets 6,000 raw data setsscans scans of 1.05 or 0.8 sec of 1 or 0.8 sec
scans scansArchival storage CD-R, MOD CD-R, MOD CD-R, MOD CD-R, MOD
Colons separate data on similar models of a device. This is the second of* Range of CT numbers is -10,240 to +30,710 with extended Hounsfield unit scale. three pages covering
the above model(s).These specificationscontinue onto thenext page.
at % at ≤4 rads 5 at 0.3 at 5 at 0.3 at 5 at 0.3 at 5 at 0.3 at1.58 rads at 90 mAs 1.58 rads at 90 mAs 1.58 rads at 90 mAs 1.58 rads at 90 mAs
Noise,% at ≤2.5 rads 0.19 0.19 0.19 0.19
CORONARY ARTERYCALCIFICATION
SCORING NA NA Yes Yes
DICOM 3.0 INTERFACE Yes Yes Yes Yes
RECOMMENDED ROOMSIZE, m2 18.5 18.5 18.5 18.5
POWER REQUIREMENTS 190-480 VAC, 190-480 VAC, 190-480 VAC, 190-480 VAC,3-phase, ≤48 kVA 3-phase, ≤48 kVA 3-phase, ≤48 kVA 3-phase, ≤48 kVA
PLANNING & PURCHASEList price,
std configuration Not specified Not specified Not specified Not specifiedSystem warranty 1 year 1 year 1 year 1 yearX-ray tube warranty 130,000 scan sec 130,000 scan sec 130,000 scan sec 130,000 scan secDelivery time, ARO Not specified Not specified Not specified Not specifiedTraining w/purchase Yes Yes Yes Yes
Remote diagnostics Yes Yes Yes YesYear first sold 2001 1999 1999 2001USA installations Not specified Not specified Not specified Not specifiedWorld installations Not specified Not specified Not specified Not specifiedFiscal year October to September October to September October to September October to September
Colons separate data on similar models of a device. This is the first of* 105 msec using HeartView. three pages covering** 16-slice mode. the above model(s).*** Optional 0.5 sec (229°). These specifications† Pinhole method: 0.9 x 0.9 (small), 1.5 x 1 (large); IEC standard: 1.1 x 1.1 (small), 1.7 x 1.7 (large). continue onto the
Vertical, cm 48-102 48-102 48-102 30-91Longitudinal, cm 200 200 200 182
Scannable range, cm 157 157 157 143Max load capacity
with accuracy, kg 200 200 200 205
IMAGE PROCESSINGComputer CPU Multiple Intel-based Multiple Intel-based Multiple Intel-based Not specified
servers with Dual servers with Dual servers with DualPentium IV Pentium IV Pentium IV
Scan FOVs, cm 50 50 50 18, 24, 32, 40, 48
Reconstructionmatrixes 512 x 512 512 x 512 512 x 512 512 x 512
Reconstruction timePer slice, sec 0.7 0.17 0.17 Not specified
For localizationscan, sec Real time Real time Real time Real time
DISPLAYMonitor size 18" LCD or 21" CRT 18" LCD or 21" CRT 18" LCD or 21" CRT 21"Matrixes, pixels 1024 x 1024 1024 x 1024 1024 x 1024 1024 x 1024
Range of CT numbers -1,024 to +3,071 ** -1,024 to +3,071 ** -1,024 to +3,071 ** -1,024 to +8,191Image enlargement Yes Yes Yes Up to 16x
Max no. of slicesdisplayed at once 64 64 64 32
IMAGE STORAGEHard disk, GB 108 223 223 12
No. online images 60,000 100,000 100,000 8,000
Archival storage CD-R, MOD CD-R, MOD CD-R, MOD 5.25" MOD drive
Colons separate data on similar models of a device. This is the second of* Couch-feed speed. three pages covering** Range of CT numbers is -10,240 to +30,710 with extended Hounsfield unit scale. the above model(s).
at % at ≤4 rads 5 at 0.3% at 1.7 5 at 0.3% at 1.7 5 at 0.3% at 1.7 2.5 at 0.25%rads rads rads
Noise,% at ≤2.5 rads 0.29 0.29 0.29 <0.35
CORONARY ARTERYCALCIFICATION
SCORING Yes Yes Yes Yes
DICOM 3.0 INTERFACE Yes Yes Yes Yes
RECOMMENDED ROOMSIZE, m2 24 24 24 20
POWER REQUIREMENTS 380-480 VAC, 380-480 VAC, 380-480 VAC, 200 VAC,3-phase, 66-83 kVA 3-phase, 66-83 kVA 3-phase, 66-83 kVA 50/60 ±0.5 Hz,
3-phase
PLANNING & PURCHASEList price,
std configuration Not specified Not specified Not specified $630,000System warranty 1 year 1 year 1 year 1 yearX-ray tube warranty 130,000 scan sec 130,000 scan sec 130,000 scan sec See footnote *Delivery time, ARO Not specified Not specified Not specified 90 daysTraining w/purchase Yes Yes Yes 1 week at Toshiba,
1 week on-siteRemote diagnostics Yes Yes Yes YesYear first sold 2002 2002 2002 1998USA installations Not specified Not specified Not specified 57World installations Not specified Not specified Not specified 355Fiscal year October to September October to September October to September April to March
OTHER SPECIFICATIONS SureView; CARE Dose; SureView; CARE Dose; CARE DOSE; SureView; Sure Start contrastHeartView CI; HeartView CI; HeartView CI w/Cal- tracking; continuoussyngo Perfusion; syngo Perfusion; cium Scoring; syngo imaging, volumeCARE Vision CT CARE Vision CT Perfusion; CARE rendered 3-D; flyfluorscopy; CARE fluorscopy; CARE Bolus; syngo Osteo; through; BMA;Bolus; syngo Osteo; Bolus; syngo Osteo; syngo Dental; CT fluoro;syngo Dental; syngo syngo Dental; syngo syngo Pulmo; syngo ECG gating; Kid CTPulmo; syngo Image Pulmo; syngo Image image fusion pediatrics package;fusion (CT/MRI/PET); fusion (CT/MRI/PET); (CT/MRI/PET); syngo full DICOM featuresyngo LungCare; syngo LungCare; InSpace; syngo 3D set; 32 recordablesyngo 3D VesselView; syngo 3D VesselView; VesselView; syngo voice commands;syngo Fly Through; syngo Fly Through; Argus; optional 378 programmablesyngo Argus. syngo Argus. Fly Through and protocols; Image-
mA range 10-500 in 10 mA 10-500 in 10 mA 10-500 in 10 mA 10-500 in 10 mAsteps steps steps steps
Colons separate data on similar models of a device. This is the first of* MS48: 1.7 x 1.6, 0.9 x 1.3 (IEC standard); 1.6 x 1.4, 0.9 x 0.8 (IEC standard). three pages covering
the above model(s).These specificationscontinue onto thenext two pages.
std configuration $670,000 $740,000 $950,000 $1,080,000System warranty 1 year 1 year 1 year 1 yearX-ray tube warranty See footnote * See footnote * See footnote * See footnote *Delivery time, ARO 90 days 90 days 90 days 90 daysTraining w/purchase 1 week at Toshiba, 1 week at Toshiba, 1 week at Toshiba, 1 week at Toshiba,
1 week on-site 1 week on-site 1 week on-site 1 week on-siteRemote diagnostics Yes Yes Yes YesYear first sold 1998 1998 1999 1999USA installations 20 1 52 2World installations 133 2 188 21Fiscal year April to March April to March April to March April to March
Gantry weight, kg 1,750Gantry aperture, cm 72Scan localizer Laser
X-RAY TUBEX-ray tube anode
Heat storage, HU 7,500,000
Heat dissipationrate, HU/min 1,386,000
Tube cooling Oil/air
Tube focal spot, mm 1.6 x 1.4, (0.9 x0.8 IEC standard)
Optional tubes Not specified
X-RAY GENERATORkW output 60kVp range 80, 100, 120, 135
mA range 10-500 in 10 mAsteps
Colons separate data on similar models of a device. This is the first ofthree pages coveringthe above model(s).These specificationscontinue onto thenext two pages.