[RADIO 250] LEC 09 Basic Ultrasound (1).pdf
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Shah Regina Isa Gee UPCM 2016 1: XVI, Walang Kapantay! 1 of 9
RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
Paayos ng page numbers saka last page
I. PRINCIPLES OF ULTRASOUND
A. What is Ultrasonography • Use of sound waves beyond the audible frequency (>20,000 Hz)
for diagnostic purposes • Can be used for therapeutic purposes by using larger and
continuous dosages as in: o Generation of heat – treatment of low back pain and muscle
strains, promotion of tissue generation o Pulverization of kidney stones
B. Basic Physics
TRANSDUCER
• Probe holding a piezoelectric crystal that changes electrical current into sound waves and vice versa
• Generates the sound wave
SOUND WAVES • Are generated, reflected off tissues and “echo”
back • Then they are picked up by the transducer and
converted to electrical activity
• Image generated depends on the time it takes the sound waves to return to the transducer and the amplitude of the sound wave o Fat or bone is a reflective surface o Air or water does not reflect sound very well o Shorter the time, the nearer the body part is to the transducer. o Stronger amplitude, the better reflector is the body part such as
bone, fat, and calcification.
II. ULTRASOUND METHODS A. Pulse Echo
A MODE – Amplitude Modulation • Echoes are displayed in graphic form, such as in echocardiogram • Not used anymore
Figure 1. A-‐mode trace. The A-‐mode is a trace indicating echo
intensity tissue with depth. In this example, there is a fluid space (6–10 cm) from which no echoes arise. Tissues superficial and deep to this produce echoes of varying intensities and there is a particularly strong echo from the skin (0–5 cm). The time gain compensation
(TGC) curve is also shown.
B MODE – Brigthness Modulation • Echoes are displayed as different intensities of brightness, giving a
2D cross sectional image (“picture”) • Can be static or dynamic (“real time”) o Static – med tech does the procedure then results are
interpreted by doctor
o Dynamic – doctor does the procedure and results are interpreted right there
M MODE – Motion Mode • First ultrasound modality to record display moving echoes from
the heart. Good to get heart tone o Thus the motion could be interpreted in terms of myocardial
and valvular function • Combination of A and B modes • Determines velocity of a specific organ
Figure 2. M-‐mode trace. The echo intensity is displayed as
brightness and the trace is swept across the screen so that the x-‐axis represents time. This is an M-‐mode echocardiogram showing the rapid movement of the mitral valve apparatus within the left ventricle (LV), with thicker proximal and distal moving bands
representing the myocardium. RV = right ventricle.
B. Doppler Method • For vascular ultrasound • Sound waves bounced off of different objects have different
frequencies à use of these frequencies to check flow through arteries and vein
• With Doppler ultrasound, these different frequencies are transformed into audible sounds, of different frequency.
• The different frequencies can also be mapped to give a visual representation as well as an audible one
• Can assess patency of arterial grafts, obstruction to flow by thrombi or atherosclerosis
• Arterial flow can often be heard in cases where it cannot be palpated
• For moving objects, the velocity of the sound waves will depend on the velocity of the moving object
• Renal artery stenosis is diagnosed when velocity is more than 300 m/s.
• Carotid artery stenosis if more than 100 m/s
III. Image Interpretation Sagittal View • Entering beam is along the long axis of the patient
OUTLINE I. Ultrasound Principles II. Ultrasound Methods III. Image Interpretation IV. Advantages and Disadvantages V. Applications
A. Abdomen
B. Obstetrics and Gynecology C. Thyroid D. Scrotum E. Breast and Musculoskeletal F. Doppler Imaging G. Interventional Procedures
Shah Regina Isa Gee UPCM 2016 1: XVI, Walang Kapantay! 2 of 9
RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
Figure 3. Ultrasound, sagittal view
Axial View • Beam is along the transverse (short) axis
Figure 4. Ultrasound, axial view
B. Information Provided
• Evaluate the size, shape and parenchyma of solid organs • Categorize lesions into solid (usually malignant), cystic (usually
benign) or complex (mixed) • Determine vascular supply of organs or masses • Localize site for biopsy, aspiration or interventional procedures
IV. ADVANTAGES AND DISADVANTAGES
Advantages • Non-‐invasive, simple and inexpensive • No ionizing radiation • Diagnosis is made during the procedure, unlike in x-‐ray • Infinite number of sections, not limited to sagittal and axial views • Portable machine, handheld even
Disadvantages
• Operator dependent • Gives only a morphologic diagnosis, the size and shape, but not the function, e.g., kidney may appear normal but may have high creatinine already; same goes for liver
• Cannot penetrate air or bone so do only chest ultrasound if you’re suspecting pleural effusion and joint effusion, bursitis, etc. Bone tumors, marrow pathologies, don’t use ultrasound
• Requires good contact of transducer with skin: this is a problem for burn patients especially if with bandage and infection
V. APPLICATIONS
• Abdominal • Obstretics and Gynecology • Small organs:breast, thyroid, scrotal, musculoskeletal • Neurosonology for pediatric patients, if fontanels are still open;
for adults can also look at Circle of Willis; not used to visualize brain parenchyma
• Vascular • Interventional procedures
A. Abdomen Liver • Describe the parenchyma Normal Appear homogenously grey Blood vessels are dark
Fatty liver (Steatosis) Appear bright (hyperechoic)
Liver Cirrhosis Small liver Heterogenous
Cystitic Lesion Hypo-‐ or anechoic (dark) with thin walls Posterior acoustic enhancement (PAE): since sound waves passes through fluid only, they are not as attenuated as passing through a normal liver parenchyma Abscess looks similar
Masses/ Modules Picture:liver metastasis of a colon carcinoma Also hypoechoic BUT NO PAE
Calcifications Picture: arrows point to a liver calcification secondary to a CMV infection Hyperechoic followed by hypoechoic portion
Pancreas
Shah Regina Isa Gee UPCM 2016 1: XVI, Walang Kapantay! 3 of 9
RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
Figure 5. Pancreas
• Usually taken in axial view • Tadpole-‐shaped, with the spleen on the left • Hypoechoic relative to others • Organ is anterior to the splenic artery and portal vein (markers) • Any structure anterior to your splenic vein is the pancreas.
Spleen
Also homogenously gray May be compared with liver, but smaller Figure 5 (left). Normal spleen ultrasound.
Gallbladder and Biliary Tree • Normally, gallbladder is thinwalled. • If painful, gallbladder is edematous.
Calcification (Stones) • Picture: cholelithiasis with mobile gallstones
• Hyperechoic with shadow • Settle on the dependent portion
• Presence of stones but px is asymptomatic, gall bladder would have thin walls
• (+) stones & (+) symptoms (pain, etc), gall bladder would be thick walled
Crystals (e.g Cholesterolosis) • Picture: cholesterol crystals in the intrahepatic bile ducts in a patient after cholecystectomy
• Hyperechoic with comet-‐tail artifact
• Not seen on CT or MRI, only in UTZ
Polyps • Nodular structure, not
dependent on gravity • Wall-‐adherent,
hyperechoic with no shadow
Ascariasis • Calcified if dead
Cholecystitis • Wall thickening (gray)
Doppler • Uncolored tubular
structure above colored tubular structure (portal vein) is the common bile duct.
• To look for the common bile duct, look for the portal vein first. The portal vein is parallel to the common bile duct. It would be helpful to trace the bileduct to the pancreas since most pathologies are found in that location.
Gastrointestinal Tract • Ultrasound is usually not used for the gastrointestinal tract
because it is mostly air-‐filled structures
Figure 6. GI tract
1st figure: sagittal view; 2nd figure: axial view; 3rd figure: thickening of wall
Appendix
Shah Regina Isa Gee UPCM 2016 1: XVI, Walang Kapantay! 4 of 9
RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
• A blind-‐ending non-‐compressible structure that does not exceed 6 mm in length
• If structure is very firm, more than 6 mm, and hypervascular/hyperemic (in doppler) à consider appendicitis
• Negative ultrasound result does not rule out appendicitis. • If appendix is retrocecal in location, it cannot be visualized in UTZ
Figure 7. Appendix
TOP: Normal (left) versus inflamed (right) appendix. BOTTOM: thickened appendix (you know because it is a dead end).
Only find it if it is inflamed
Kidney
NORM
AL KIDNEY
• Homogenous parenchyma with uniform contour
• Central echocomplex (corresponds to pelvocalices; only seen when dilated)
• Hypoechoic focus in the middle (medulla with collecting tubules) with grey in the periphery (cortex with glomeruli)
STAG
HORN
CAL
CULI
• Large calculi that takes the shape of the medulla
HYD
RONEP
HRO
SIS
• Distension and dilation of the renal pelvis and calyces
MED
ULLAR
Y NEP
HRO
CALCINOSIS
• Calcified renal medulla
• Seen in distal renal tubular acidosis, renal tuberculosis and medullary sponge kidney disease
RENAL
CYSTS
• Picture: multiple renal cysts in right kidney
END-‐STA
GE KIDNEY
• Hyperechoic parenchyma (significantly more echogenic than adjacent liver parenchyma)
• Differentiation of cortex from medulla, and even from the renal sinus, is lost
• Irregular kidney borders + small kidney size • Etiology: Infection, hypertensive nephropathy, diabetes
• There are normal variants of the kidney. Such are the Dromedory humps and hypertrophied column of Bertin
Ureter • Normally should not be distended • it can’t be seen in the UTZ if there are no pathologies • Calculi (stones) of the ureters are usually detected through UTZ
Figure 8. Ureteral Stones.
Image at Left is a stone in the ureterovesical junction Urinary Bladder • Normally should not be distended • If there is cystitis, the urinary bladder can have thick walls. • Hemorrhage in the urinary bladder will appear hyperechoic
Shah Regina Isa Gee UPCM 2016 1: XVI, Walang Kapantay! 5 of 9
RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
NORM
AL BLA
DDER
• Appears hypoechoic with well-‐defined borders
BLAD
DER
TUMORS
• Picture: large bladder carcinoma with bladder wall invasion
STONES
• Picture: mobile bladder stones
• Hyperechoic with posterior shadowing
CYSTITIS
• Cystitis: irregular thickening of wall, balloon of foley catheter is seen at the right.
FOLEY CA
THETER
BAL
LOON
• Picture: balloon catheter placed in the vagina and not in the bladder
Prostate • Two views: transrectal (good view since few structures are in the
way) and transabdominal (bladder must be full) • Central (slightly hypoechoic) and peripheral (hyperechoic) gland
can be seen • Normal volume: 20 cc
NORM
AL PRO
STAT
E
• Picture: arrows point to each lobe of the prostate
BENIGN PRO
STAT
IC
ENLA
RGEM
ENT
• Usually located on the central zone
PROSTAT
IC CAR
CINOMA
• Picture: note hypoechoic nodule (arrow) located on the peripheral zone
CALCIFICAT
IONS
• Appear as hyperechoic foci usually from 4-‐7 mm in the inner gland of the prostate and also along the prostatic urethra
B. Obstetrics and Gynecology
Transabdominal vs. Transvaginal Ultrasound
Table 1. Comparison between transabdominal and transvaginal UTZ.
TRANSABDOMINAL TRANSVAGINAL • Distended urinary bladder • Low frequency transducer (up to 5)
• For visualizing the global picture
• Poor resolution
• Empty urinary bladder • High frequency transducer (up to 7.5)
• Limited range (8 to 10 cm away from probe only)
• Excellent resolution • Long axis and short axis orientation
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RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
Figure 9. Transabdomial VS Transvaginal
Figure 10. Transabdominal orientation
Figure 11. Transvaginal orientation
The Fetus • UTZ is useful for visualizing fetal organs (feet, genitals, face,
cranium, hands, etc.) • Fetal assessment for sex:
o Not easily detectable, can take up to 30 minutes o Turtle sign is for male, hamburger sign is for female
Figure 12. Early Intrauterine
Figure 13.
TOP: 19-‐week baby boy showing turtle sign on ultrasound. BOTTOM: 20-‐week baby girl showing hamburger sign on ultrasound.
C. Thyroid
• Very radiosensitive organ, hence best examined through UTZ
NORM
AL THYR
OID
• Picture: right lobe of thyroid relative to other organs
• Homogenously gray
• Hyperechoic when compared to muscle
• Normal size threshold: 5 cm
GRA
VES' DISEA
SE
• Picture: hyper-‐vascularized thyroid gland (thyroid inferno) on color Doppler
• Enlarged and relatively hypoechoic
• heterogenous parenchyma, >5cm, isthmus and AP diameter are measured
Shah Regina Isa Gee UPCM 2016 1: XVI, Walang Kapantay! 7 of 9
RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
HAS
HIM
OTO
'S THYR
OIDITIS
• Enlarged and non-‐homogenous; hypervascular in its acute stage
• Hypoechoic compared to normal thyroid with lobulations inisde
BENIGN THYR
OID M
ASS
• Picture: hyperplastic adenomatous nodule with a slightly hyperechoic vascularized mass
THYR
OID CAR
CINOMA
• Picture: nonhomogeneous hypervascularized solid and partly cystic thyroid mass that proved to be extensive papillary carcinoma
COLLOID NODU
LE
• Picture: cystic changes in an adenomatous nodule (colloid nodule) in the right thyroid lobe
• Looks like sponge (multiple small internal cystic structures) • Does not warrant a biopsy
Thyroid Lesions: Benign vs. Malignant
PARAMETER BENIGN MALIGNANT
Height vs. width Wider than tall (usually ovoid) Taller than wide
Capsule Usually present Usually absent
Edge of mass Smooth, well-‐defined Poorly defined
Intra-‐lesional peripheral vascularity Absent Present
Calcifications Positioned peripherally (“egg-‐shell” configuration)
Located inside the mass
• Hyperechoic à benign • Hyperechoic + crystals à benign
• Cyst most likely benign • Thin rim calcification ath the PERIPHERY à benign
Figure 14. ????
• Colloid nodule: with internal reticulations, no calcifications • Ultrasound guided FNAB slide: Anything you can ultrasound, you
can biopsy
D. SCROTUM
NORM
AL TESTIS
• Ovoid, homogenously gray
• No calcifications or masses within
VARICO
COELE
• Picture: varicocoele with dilatated venous plexus and reflux during straining
• Looks like “bag of worms”
• Hypervascular with dilated vessels
• Can cause infertility
ORC
HITIS
• Picture: orchitis with a focal hypoechoic area with increased flow
• Whole testis enlarged, hypervascular, not homogenous
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RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
EPIDIDYM
ITIS W
ITH ABS
CESS
• Picture: arrow points to abscess below an inflamed epididymis
• Hyperemic wall
Spermatocoele vs. Epididymal Cysts • Cannot be distinguished via ultrasound
Figure 15. Epididymal cyst or spermatocele in the epididymal head. Testicular Tumors
PROBABILITY OF MALIGNANCY HIGH INTERMEDIATE LOW VERY LOW
Solid palpable Solid non-‐palpable
Simple cystic palpable
Simple cystic non-‐palpable
Complex cystic palpable
Complex cystic non-‐palpable
*Complex: presence of both solid and cystic parts
Microlithiasis and Seminoma • Microlithiasis: post-‐infection, hypoechoic with microcalcifications
à must follow-‐up for possible seminoma • Seminoma: hyperechoic, highly vascularized • Torsion: hypovascular • Infarct: avascular
Figure 16. Testicular
microlithiasis and a
seminoma with a vascularized hypoechoic
mass.
E. BREAST AND MUSCULOSKELETAL
Breast • UTZ usually for fibroadenomas o Flat ovoid masses with smooth well-‐defined borders o Solid nodule with PAE (an exception! Recall that solid masses in the GI tract do not have PAE)
o No need for biopsy, may regress normally
Figure 17. Fibroadenoma
with a hypoechoic slightly lobulated oval lesion with sharp margins.
Musculoskeletal
TENOSYNOVITIS
• Picture: tenosynovitis of the flexor digitorum tendons
• Abnormal fluid collection within synovium around covering of tendon
NEO
NAT
AL UTZ
• Picture: hemangioma with a hypechoic compressible highly vascularized lesion
• UTZ probe made to pass through fontanelles
F. CRANIAL • Assessed in neonates through the fontanelles. • Used just to rule out pathologies especially in preterms • UTZ can rule out intracranial hemorrhages.
Figure 18. Cranial UTZ
LEFT: Subarachnoid Hemorrhage: RIGHT: Hydrocephalus
G. DOPPLER IMAGING Standard Doppler Imaging • Flow direction and velocity must be shown on the color Doppler image by shifting and changing shade method
• Different colors are used to represent different frequencies and color gets lighter as the frequency increases o Color used can be changed by the technician
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RADIO 250: ICC in Radiology and Nuclear Medicine LEC 09: Basic Ultrasound
Exam 1 | Dr. Pauig| October 23, 2013
o Usual color spectrum: § Blood coming TOWARDS the probe appears blue § Blood going AWAY FROM the probe appears red § NOT red = artery, blue = vein!
• Shows direction of blood BUT is not sensitive to slow movements
Figure 19. Standard Doppler Imaging
Power Doppler Flow Imaging • Frame rate is too slow and cannot provide flow direction and velocity
• Sensitive to even slow movements • Does not assign direction • Any flowing blood is yellow.
Figure 20. Power Doppler Flow Imaging
Resistive index, acceleration index. Insert slide-‐ no pic L
H. INTERVENTIONAL PROCEDURES
Treatment Modalities Utilizing Ultrasound • Biopsy • Aspiration • Thoracentesis / Paracentesis • Percutaneous biliary drainage • Nephrostomy / Cystostomy • IV insertion / central venous lines
Ultrasound-‐Guided Procedures: Examples • Liver abscess aspiration: Abscess appears hypoechoic. Vascularity is only in the periphery. You see a collapsed wall after aspiration.
Figure 21. Liver abscess aspiration
• Prostate biopsy
Figure 22. Prostate Biopsy
• Paracentesis: evacuation of fluid within the cavity, avoid puncturing bowels
• Thoracentesis: evacuation of fluid within the pleural cavity; avoid puncturing diaphgram
END
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