AB-Abdomen Exam Preparation Material | Abdomen Sonography Examination

Explanation:
In elderly men, dysuria and nocturia often suggest lower urinary tract symptoms such as benign prostatic hyperplasia (BPH). A pelvis limited ultrasound is most appropriate to evaluate the bladder and prostate for enlargement, residual urine volume, or other causes of obstructive symptoms.
According to AIUM Practice Guidelines:
“Pelvic ultrasound can evaluate bladder volume, post-void residual, and prostate size in men with lower urinary tract symptoms.”
Reference: AIUM Practice Parameter for the Performance of Ultrasound of the Prostate, 2020.
Rumack CM, Diagnostic Ultrasound, 5th ed. Elsevier, 2017.

Explanation:
The ultrasound image demonstrates a well-defined, ovoid, hypoechoic to isoechoic mass within the subcutaneous tissue of the abdominal wall. The lesion appears compressible and shows linear striations parallel to the skin surface ― a classic appearance of a lipoma.
Lipomas are the most common benign soft tissue tumors and frequently arise in the subcutaneous tissue. They are composed of mature adipose tissue and are typically asymptomatic unless large or compressing adjacent structures.
Sonographic features of a lipoma:
Isoechoic to mildly hyperechoic or hypoechoic relative to subcutaneous fat
Oval or elliptical in shape with well-defined margins
Internal linear striations or “feathered” echotexture
Compressible and non-vascular on Doppler imaging
Located in subcutaneous fat plane parallel to the skin surface
Differentiation from other options:
B. Fibroma: Typically appears as a homogeneous, hypoechoic mass but is far less common in the abdominal wall.
C. Desmoid: Appears as an ill-defined or infiltrative mass within deeper soft tissues; more heterogeneous and may distort surrounding tissue planes.
D. Metastasis: Often more irregular, heterogeneous, and may show increased vascularity or invasion into adjacent structures.
References:
Rumack CM, Wilson SR, Charboneau JW, Levine
D. Diagnostic Ultrasound. 5th Edition. Elsevier, 2018.
Chapter: Musculoskeletal and Soft Tissue Ultrasound, pp. 1448C1450.
American Institute of Ultrasound in Medicine (AIUM) Practice Parameter for the Performance of a Diagnostic Ultrasound Examination of Soft Tissue Structures, 2020.
Radiopaedia.org. Lipoma (ultrasound): https://radiopaedia.org/articles/lipoma-ultrasound

Explanation:
Hepatic adenomas are benign liver tumors strongly associated with long-term use of oral contraceptives and are most frequently found in women under 40. Hepatoblastoma is seen in children; hepatoma (HCC) is a malignant tumor typically found in cirrhotic livers. Cavernous hemangioma is unrelated to oral contraceptives.
According to Rumack’s Diagnostic Ultrasound:
“Hepatic adenomas occur predominantly in young women with a history of oral contraceptive use.”
Reference: Rumack CM, Wilson SR, Charboneau JW, Levine
D. Diagnostic Ultrasound. 5th ed. Elsevier, 2017.
WHO Classification of Tumours of the Digestive System, 5th ed., IARC, 2019.

Explanation:
The Doppler spectral waveform shown in this image of the right testis demonstrates low-resistance, forward-flowing arterial waveforms with continuous diastolic flow ― this is characteristic of normal testicular perfusion. The presence of both color Doppler flow and a resistive index (RI) of 0.66 further supports normal testicular arterial circulation.
Key Doppler features of a normal testicular waveform:
Low-resistance waveform (RI typically 0.5C0.75)
Continuous diastolic flow
No reversal of flow or spectral broadening
Color Doppler confirms uniform intratesticular vascularity
Clinical context:
Normal testicular flow on Doppler imaging excludes testicular torsion, infarction, or significant inflammation.
Testicular torsion would show either absent or very high-resistance (reduced or absent diastolic flow) waveform.
Epididymo-orchitis may show hyperemia with low resistance but often presents with other gray-scale findings like heterogeneous echotexture or scrotal wall thickening.
Differentiation from other options:
B. Increased resistance: RI >0.75 and reduced or reversed diastolic flow; may indicate impending torsion or ischemia.
C. Tardus parvus: A slow systolic upstroke and diminished amplitude; indicates proximal arterial stenosis.
D. Triphasic: Normal waveform in peripheral arteries, such as extremities, not seen in testicular circulation.
References:
Rumack CM, Wilson SR, Charboneau JW, Levine
D. Diagnostic Ultrasound. 5th Edition. Elsevier, 2018.
Chapter: Male Pelvis C Testis and Scrotum, pp. 793C800.
AIUM Practice Parameter for the Performance of Scrotal Ultrasound Examinations, 2020.
Radiopaedia.org. Testicular Doppler assessment: https://radiopaedia.org/articles/testicular-doppler-assessment

Explanation:
The image shows a transverse view of the left lobe of the liver with the portal triads clearly visible. The "parallel channel" or "double barrel" sign is observed―where dilated intrahepatic bile ducts run alongside the portal veins, creating a characteristic sonographic pattern of paired anechoic (black) tubular structures.
This sonographic feature is diagnostic for dilated intrahepatic bile ducts and is typically seen in obstructive jaundice or biliary obstruction from conditions such as:
Choledocholithiasis (stone in the common bile duct)
Stricture or mass compressing the bile ducts
Cholangiocarcinoma
The intrahepatic bile ducts normally are too small to visualize clearly unless dilated. Their dilation gives the liver a "too many tubes" appearance, where bile ducts become as prominent as the portal veins.
Comparison of answer choices:
A. Normal intrahepatic ducts are not usually seen this clearly or prominently on ultrasound.
B. Dilated intrahepatic ― Correct. The parallel channel sign supports this diagnosis.
C. Dilated common bile duct would be visualized extrahepatically, typically anterior to the portal vein near the head of the pancreas.
D. Dilated common hepatic duct is also extrahepatic and seen in the porta hepatis, not within the liver parenchyma.
References:
Rumack CM, Wilson SR, Charboneau JW, Levine
D. Diagnostic Ultrasound, 5th ed. Elsevier; 2017.
Hagen-Ansert SL. Textbook of Diagnostic Sonography, 8th ed. Elsevier; 2017.
Taylor KJW, Burns PN, Wells PNT. Clinical Applications of Doppler Ultrasound. Raven Press; 1990.