The Sono Consultant

14 The Sono Consultant

The tables in this chapter serve as a “sono consultant”—a systematic framework for helping the examiner to evaluate specific ultrasound findings and make a differential diagnosis.

The chapter consists of two parts, which represent the situations that beginners will most often encounter in ultrasound examinations:

Part I: The examiner sees an abnormality at ultrasound and wants to analyze it in a systematic way.

Part II: The examiner is consulted for the ultrasound evaluation of a specific clinical situation.

Part I, Ultrasound Findings, provides a comprehensive, step-by-step approach for systematically analyzing an abnormality that is noted during an ultrasound examination.

Part II, Clinical Presentation, offers guidelines for interpreting findings and extracting the maximum amount of information that ultrasonography can supply in a given clinical situation.

Both parts deal with the most common sonographic findings and clinical situations that arise in diagnostic ultrasonography. Of course, the exact sequence of steps for interpreting ultrasound findings will vary considerably from one examiner to the next. The goal of this chapter is to provide the beginner with a logical, structured routine that will train and reinforce a complete, systematic ultrasound examination.

I Ultrasound Findings

1. Aorta: Widening

Finding	Interpretation
Verify, measure in two dimensions
< 25mm	Normal
25–30mm	Ectasia
> 30mm	Aneurysm
> 50mm	High risk of rupture
Full-length visualization of the aorta
Longitudinal shape Straight Curved	Kinked?
Wall Circumscribed plaques, diffuse thickening	Aortic sclerosis?
Lumen Echo-free Echogenic Floating membrane	Thrombus? Dissecting aneurysm
Location Start and end of the dilatation Relationship to vessels – Suprarenal – Infrarenal?
Aortic branches Vessel origins Iliac vessels

2. Vena cava: Dilatation

Finding	Interpretation
Verify, measure
< 20mm in late inspiration and end expiration	Normal
> 20mm	Suspicious for abnormal dilatation Stasis?
Pulsation, respiration, lumen
Double-beat pattern synchronous with the pulse Present Not present	Physiologic dilation? Young, thin patient? Stasis?
Luminal change with respirations Present Not present	Physiologic dilation? Stasis?
Lumen Echo-free Echogenic	Stasis? Thrombus?
Other signs of congestive failure
Visualization of all vena cava tributaries Hepatic veins Renal veins Iliac vessels
Liver Echo pattern Borders Size
Ascites?

3. Liver: Large

Finding	Interpretation
Verify enlargement, measure
Measure in medioclavicular line (MCL), left lobe Caudate lobe	Liver enlarged? Thoracic emphysema? Riedel lobe?
Shape of liver, borders
Rounded inferior border	Fatty liver?
Increased inferior angle	Liver fibrosis? Hepatic cirrhosis?
Echo pattern
Hyperechoic	Fatty liver? Fibrosis? Alcoholic cirrhosis? Chronic hepatitis?
Hypoechoic	Acute hepatitis? Congested liver?
Inhomogeneous	Disseminated metastasis?
Hepatic veins
Narrowed	Fatty liver? Fibrosis? Alcoholic cirrhosis?
Dilated	Congested liver?
Associated findings
Ascites
Pleural effusion	Congested liver?
Splenomegaly
Prominent vena cava

4. Liver: Small

Finding	Interpretation
Verify, measure
Liver 15–16 cm in MCL, normal size	Elevation of the diaphragm?
Liver small	Cirrhosis?
Shape of liver
Posterior surface wavy, nodulated	Posthepatic cirrhosis?
Rounded inferior border	Alcoholic cirrhosis?
Echogenicity
Hyperechoic	Alcoholic cirrhosis?
Coarsely granular, speckled	Hepatitis?
Vessels
Portal vein: pruning Hepatic veins: narrowed or irregular	Hepatic cirrhosis?
Circumscribed changes
Masses	Hepatocellular carcinoma (HCC)?
Additional or associated findings
Ascites? Widening or portal vein or splenic vein? Large spleen? Recanalized umbilical vein? Thickening of gallbladder wall? Pleural effusion?

5. Liver: Increased echogenicity

Finding	Interpretation
Verify
Hyperechoic to kidney	Increased density
Posterior acoustic shadowing	Increased density
Size of liver
Large or normal	Fatty liver? Fibrosis? Cirrhosis? Congested liver? Disseminated metastasis? Disseminated HCC? Lymphoma?
Small	Cirrhosis? Disseminated HCC?
5.1 Liver: Increased echogenicity, liver large
Finding	Interpretation
Echo pattern
Homogeneous	Fatty liver? (alcohol, diabetes mellitus, hypertriglyceridemia, obesity, drugs, pregnancy) Fibrosis? Cirrhosis?
Inhomogeneous	Disseminated metastasis? Disseminated HCC? Lymphoma? Fatty infiltration or sparing? Congested liver?
Shape
Inferior angle rounded, blunted, irregular, nodular	Alcoholic cirrhosis? Disseminated metastasis?
Hepatic veins
Narrow	Fibrosis? Cirrhosis?
Broad	Congested liver?
5.2 Increased echogenicity, liver small
Finding	Interpretation
Echo pattern
Homogeneous	Cirrhosis?
Inhomogeneous	Disseminated metastasis?
Hepatic veins
Narrow	Cirrhosis?

6. Liver: Hepatic veins dilated

Finding	Interpretation
Verify
< 5 mm before termination at vena cava	Normal?
> 5 mm before termination at vena cava	Dilated?
Position-dependent lumen changes
Present	Physiologically large hepatic veins (young patients)
Not present	Congestion?
Liver size
Large	Acute congestion?
Normal size	Chronic congestion?
Small	Chronic congestion? Cardiac cirrhosis?
Echo pattern
Slightly echogenic	Acute congestion?
Moderately echogenic	Chronic congestion?
Very echogenic	Chronic congestion?
Other findings
Ascites, pleural effusion, splenomegaly	Congestive failure?

7. Liver: Circumscribed mass

Finding	Interpretation
Echogenicity
Echo-free	See below
Hypoechoic	See p. 255
Isoechoic	See p. 256
Hyperechoic	See p. 257
Hyperechoic with acoustic shadow	See p. 257

8. Liver: Echo-free mass

Finding	Interpretation
Verify, check cystic criteria
No internal echoes, posterior enhancement, edge shadows	Fluid-filled mass, cyst
Shape
Rounded	Simple cyst?
Scalloped	Hydatid cyst?
Irregular	Abscess? Necrotic tumor?
Margins
Sharp, thin	Simple cyst
Sharp, echogenic, calcifications	Hydatid cyst?
Indistinct, blurry	Abscess?
Irregular	Hematoma?
Internal echoes
Septa	Hydatid cyst?
Inhomogeneous areas	Abscess?
Echo-free	Simple cyst?
Location
Intrahepatic	Hepatic cyst?
Inferior hepatic border	Gallbladder? Choledochal cyst? Cavernous transformation?
Other findings: number, size

9. Liver: Hypoechoic mass

Finding	Interpretation
Shape
Rounded	Lymphoma?
	Adenoma?
	Focal nodular hyperplasia (FNH)?
	Metastasis?
	HCC?
Scalloped	Metastasis?
	HCC?
	FNH?
Irregular	Abscess?
	Hematoma?
	Infarction?
	Focal fatty sparing?
Echo pattern
Homogeneous	Hemangioma? Lymphoma?
Inhomogeneous	Metastasis? HCC? Lymphoma?
Hypoechoic rim	Metastasis? HCC?
Margins, outline
Smooth, sharp	Adenoma? FNH? HCC?
	Lymphoma? Metastasis?
	Focal fatty sparing?
Indistinct	Infarction? Hematoma? Abscess?
Number
Solitary	Infarction? Abscess? Adenoma? FNH? HCC?
	Hematoma?
Multiple	Metastases?
Numerous	Metastases? Lymphomas?
Other findings
Signs of cirrhosis, search for primary tumor (pancreas, kidney, gallbladder, bowel, gynecologic tumor, ascites)

10. Liver: Isoechoic or hyperechoic mass

Finding	Interpretation
Shape
Rounded	FNH? HCC? Metastasis? Hemangioma?
Irregular, polygonal	HCC? Zonal fatty infiltration? Round ligament?
Echo pattern
Homogeneous	Hemangioma?
Inhomogeneous	Hemangioma? Metastasis? HCC?
Margins
Smooth, sharp	Hemangioma? Adenoma? HCC? Lymphoma? Metastasis? Zonal fatty infiltration?
Number
Solitary	HCC? Adenoma? FNH?
Multiple	Metastases?

11. Liver: Hyperechoic mass with an acoustic shadow

Finding	Interpretation
Shape
Rounded	Metastasis? Hemangioma? Calcification?
Irregular, polygonal	Metastasis? Round ligament?
Echo pattern
Homogeneous	Round ligament? Hemangioma? Calcification?
Inhomogeneous	Metastasis?
Number
Solitary	Hemangioma? Round ligament?
Multiple	Metastases? Calcifications? Hemangiomas?

12. Ascites

Finding	Interpretation
Verify
Floating bowel loops	Ascites?
Absence of floating bowel loops	Ovarian cyst? Cystic ovarian tumor?
Check sites of predilection
Morrison’s pouch Perihepatic Perisplenic Retrovesical	Ascites?
Sites of predilection are clear	Ovarian cysts? Cystic ovarian tumor?
Investigate cause
Signs of cirrhosis Portal vein dilated Splenic vein dilated Splenomegaly	Hepatic cirrhosis?
Hepatic veins dilated	Congestive failure? Budd–Chiari syndrome?
Signs of pancreatitis	Pancreatitis?
Signs of peritonitis	Bowel obstruction? Peritonitis?
Mass in Liver Gallbladder Pancreas Bowel Lymph nodes	Malignant tumor?

13. Gallbladder: Stone

Finding	Interpretation
Verify
Hard echo	Stone? Air in duodenum?
Acoustic shadow: no	Cholesterol polyp?
Acoustic shadow: yes	Cystic edge shadow? Artifact in gallbladder neck? Kinked gallbladder?
Mobility	Gravel? Stone?
Stone characterization Size, number, location, ultrasound appearance
Hard, crescent-shaped echo	Heavy calcification
Hard entry echo, moderate internal echoes	Moderately heavy calcification
Soft entry echo, marked internal echoes	Slight calcification Cholesterol stone?
Inhomogeneous with some hard internal echoes, irregular outline	Pigment stone?
Gallbladder size
Small	Shrunken gallbladder? Contraction?
Normal	Uncomplicated stone?
Enlarged (see p. 262)	Hydrops? Empyema?
Gallbladder wall
Normal	Uncomplicated stone
Thickened (see p. 261)	Cholecystitis? Neoplasm?
Compressibility
Compressible, painless	Uncomplicated stone
Poorly compressible, painful	Hydrops? Empyema?
Biliary tract
Stone in the gallbladder neck	Stone with check-valve mechanism?
Stone in common duct, dilated commonduct	Choledocholithiasis?
Gallbladder function
Fluid-filled lumen	Uncomplicated stone?
No detectable residual lumen	Contraction? Shrunken gallbladder? Completely filled with stones?
Contracts in response to stimulus	Functional gallbladder?
No contractions	Nonfunctioning gallbladder
Other findings
Signs of pancreatitis?	Chologenic pancreatitis?

14. Gallbladder: Circumscribed wall changes

Finding	Interpretation
Visualize in two planes
Patchy	Crease due to fold? Septum? Heister valve?
Spherical structure	True mural lesion?
Mobility
Yes	Stone? (see p. 259) Polypoid sludge?
No	Mural lesion
Size
<5mm
>5mm
>10mm	Cholesterol polyp? Adenoma? Adenoma? Carcinoma?
Contact with wall
Pedunculated	Cholesterol polyp?
Sessile	Adenoma? Carcinoma?
Echogenicity
Hyperechoic	Cholesterol polyp? Incrusted stone?
Hypoechoic	Adenoma? Carcinoma?
Number
Multiple	Cholesterol polyp?
Solitary	Adenoma? Carcinoma?
Shape
Irregular	Cholesterol polyp? Carcinoma?
Rounded	Adenoma? Carcinoma?
Other causes
Adenomyomatosis (rare) Metastasis (rare)

15. Gallbladder: Thickened wall

Finding	Interpretation
Verify
>4mm in fasted state	Thickening?
Echo pattern
Homogeneous, hyperechoic	Chronic cholecystitis? Echogenic fat on gallbladder wall?
Homogeneous, hypoechoic	Wall thickening due to ascites? Acute hepatitis? Congestive failure?
Inhomogeneous, hyperechoic	Chronic cholecystitis?
Inhomogeneous, hypoechoic	Acute cholecystitis? Tumor?
Gallbladder contents
Stone	Stony gallbladder?
Echogenic material	Acute cholecystitis?
Obliterated lumen	Shrunken gallbladder? Tumor?
Gallbladder surroundings
Edema	Acute cholecystitis?
Pain on compression	Acute cholecystitis?
Signs of cirrhosis, ascites	Wall thickening due to cirrhosis?
Signs of congestive failure	Wall thickening due to congestive failure?
Rare causes
Dysproteinemia Lymphoma Adenomyomatosis