ARDMS AB-Abdomen - Abdomen Sonography Examination

Direct inguinal hernias protrude through Hesselbach's triangle, which lies medial to the inferior epigastric artery. In contrast, indirect inguinal hernias pass lateral to the inferior epigastric artery via the deep inguinal ring.

According to Moore’s Clinically Oriented Anatomy:

“Direct inguinal hernias occur medial to the inferior epigastric vessels, within Hesselbach's triangle.”

Testicular metastases are rare and usually identified in older patients. The most frequent primary site of malignancies metastasizing to the testes is theprostate. Studies (Ulbright and Young, 2008; Mosharafa et al., 2003) indicate that prostatic adenocarcinoma accounts for the highest number of testicular metastases, with lung and gastrointestinal tract malignancies also contributing less frequently. These metastases can be unilateral or bilateral and are often discovered incidentally during surgical intervention for prostate cancer.

The metastatic route involves retrograde venous extension, arterial embolism, or lymphatic dissemination. Histologically, prostatic adenocarcinoma in the testis can be confirmed viaimmunohistochemical markers like prostate-specific antigen (PSA), supporting its prostatic origin.

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.”

Thyroid adenomas typically present as well-defined nodules surrounded by a thin, hypoechoic peripheral halo representing compressed thyroid parenchyma or fibrous capsule. Irregular margins suggest malignancy.

According to Rumack’s Diagnostic Ultrasound:

“A thin hypoechoic halo is characteristic of benign thyroid adenomas.”

The ultrasound image labeled “SAG RUQ KIDNEY” demonstrates a midline sagittal view showing a renal parenchymal structure that extends across the midline anterior to the aorta and vertebral bodies, suggesting the presence of a horseshoe kidney.

A horseshoe kidney is a congenital renal anomaly in which the lower poles of both kidneys are fused across the midline by a parenchymal or fibrous isthmus. This isthmus typically lies anterior to the aorta and inferior vena cava and can be seen as a hypoechoic band of tissue crossing the midline on ultrasound.

Ultrasound findings characteristic of a horseshoe kidney:

Abnormally low position of the kidneys in the abdomen

Renal tissue (isthmus) bridging the lower poles anterior to the great vessels

Renal axes may be more horizontal than usual

Kidneys may appear closer together or “kissing” the spine anteriorly

Differentiation from other options:

A. Duplicated collecting system: Manifests as two separate collecting systems within one kidney, often with a central renal sinus split into two — not typically midline bridging.

B. Crossed renal ectopia: Involves one kidney crossing midline and fusing with the other on the opposite side, but they do not form a midline isthmus.

D. Pelvic kidney: A single kidney located in the pelvis due to failed ascent — it does not appear as midline fusion of two kidneys.

Urinomas are collections of urine in the retroperitoneum that result from trauma, surgery, or obstruction causing urine leakage. Trauma is a frequent cause of urinoma formation due to disruption of the urinary tract.

According to Rumack’s Diagnostic Ultrasound:

“Urinomas may develop as a complication of trauma, surgery, or obstructive uropathy with urinary extravasation into the retroperitoneum.”

Conn syndrome (primary hyperaldosteronism) results from excessive aldosterone secretion, often due to an adrenal adenoma, leading to hypertension, hypokalemia, and metabolic alkalosis. Cushing disease involves cortisol, Addison disease involves adrenal insufficiency, and Waterhouse-Friderichsen is associated with adrenal hemorrhage.

According to Rumack’s Diagnostic Ultrasound:

“Conn syndrome is due to excessive secretion of aldosterone, often secondary to adrenal cortical adenoma.”

Intrahepatic biliary dilatation with a normal common bile duct (CBD) is typically caused by obstruction located at or above the level of the hepatic duct confluence. A tumor at the porta hepatis, such as cholangiocarcinoma (Klatskin tumor), is a classic cause of this pattern. The porta hepatis is the site where the right and left hepatic ducts join to form the common hepatic duct. A mass at this location can obstruct the intrahepatic ducts while leaving the distal CBD unaffected and of normal caliber.

By contrast:

Portal vein thrombus (A) affects vascular flow but does not directly obstruct bile ducts.

Choledocholithiasis (C) obstructs the CBD, typically resulting in both intrahepatic and extrahepatic duct dilatation.

Acute pancreatitis (D) may cause distal CBD compression if there is associated inflammation or pseudocyst formation, but typically results in extrahepatic duct dilatation rather than isolated intrahepatic dilation.

Reference Extracts:

Rumack CM, Wilson SR, Charboneau JW, Levine D. Diagnostic Ultrasound, 5th ed. Elsevier, 2017. Chapter: Biliary Tract: “Klatskin tumors cause proximal (intrahepatic) biliary dilatation while the distal bile duct remains normal in caliber.”

Gore RM, Levine MS. Textbook of Gastrointestinal Radiology, 4th ed. Saunders, 2015.

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Power Doppler measures the amplitude (strength) of Doppler signals rather than frequency shift, making it more sensitive to low-velocity and small-vessel blood flow. Its primary advantage is an improved signal-to-noise ratio, allowing for better visualization of slow or weak flow.

A: Power Doppler is more sensitive to motion artifacts, not less.

B: It is still angle dependent, though somewhat less so than color Doppler.

D: Power Doppler does not display flow direction (a limitation).

Reference Extracts:

Kremkau FW. Sonography Principles and Instruments. 9th ed. Elsevier, 2015.

Rumack CM, Wilson SR, Charboneau JW, Levine D. Diagnostic Ultrasound. 5th ed. Elsevier, 2017.