Diagnostic imaging clinics

RADIOLOGY-medical specialty that uses imaging to diagnose & treat diseases seen within the body.

DIAGNOSTIC RADIOGRAPHYULTRASONOGRAPHYNUCLEAR MEDICINECOMPUTED TOMOGRAPHY MAGNETIC RESONANCE IMAGINGAnd other emerging modalities

Veterinary Diagnostic Imaging- use of imaging modalities to diagnose diseases in animals.

DIAGNOSTIC RADIOGRAPHYAlso known as X-rays or radiographsX-rays pass thru the animal and image is recorded on radiographic filmMost useful for bones, lungs and areas of varying contrast.

Advantage-1-accessible/inexpensive2-no need to anaesthetize/sedate3-shows detail where there is contrast

Disadvantage-1-exposure to ionizing radiation2-2D image of 3D structure so..

*Always take 2 views at right angles!!!!!*Currency-opacity

Courtesy: www.universalimaginginc.com

Contrast Radiography

Use of contrast agents to increase or decrease opacity of the part.Positive Contrast-eg barium sulphateNegative Contrast-eg air, oxygenDouble Contrast-both positive & negative agents to optimize mucosal viewing.

ULTRASONOGRAPHYAlso known as echo/sonogramPiezoelectric crystal generates sound and probe ‘listens’ for echo which is then used to create an imageAdvantage1-no need for anaesthesia / sedation

2-no ionizing radiationDisadvantage-1-equipment is relatively expensive

2-not useful for bone or gas filled organsCurrency-echogenicity

NUCLEAR MEDICINEAlso known as nuclear scintigraphyRadioactive chemicals (radiopharmaceuticals eg Technetium 99m-TC) are given to the animal and the amount of radiation is recorded by a scintillation detector (gamma camera)Differs from others in that it studies function and not anatomyAdvantage-1-organ specific

2-more sensitive but less specificDisadvantage-1-requires anaesthesia

2-radioactive so animals must be isolated for 48hours

3- images are small and lack detail 4-equipment is very expensive

Currency-activity or accumulation

COMPUTED TOMOGRAPHYAlso known as CT/CAT scanX-rays are passed thru the body and a computer measures its attenuation while the X-ray tube travels around the body so multiple slices of images are takenEven tho 2D, reconstruction into 3D takes placeAdvantage-1-can be used for any type of organ/tissueDisadvantage-1-anaesthesia is mandatory

2-equipment is very expensive 3-radiation exposure is massive

Currency-opacity

MAGNETIC RESONANCE IMAGINGAlso known as MRIPatient is placed in a large magnet and radiofrequency pulses are administered to align the hydrogen molecules which resonate when they realign and this is used to form imagesAdv-1-latest technology

2-gives best contrast of soft tissues and blood flowDisadv-1-prohibitively expensive

2-poor orthopaedic use except for ligaments and joint soft tissues

Currency-signal intensity