Last Attempt AB-Abdomen Questions

Annular pancreas is a congenital anomaly in which pancreatic tissue encircles the second part of the duodenum, potentially causing partial or complete duodenal obstruction (atresia). It is due to abnormal migration of the ventral pancreatic bud.

According to Rumack’s Diagnostic Ultrasound:

“Annular pancreas results from failure of the ventral pancreatic bud to rotate properly, leading to encirclement of the duodenum.”

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.”

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.”

Wooden foreign bodies are often difficult to detect on CT because of their low radiodensity, but they are highly echogenic with posterior shadowing or reverberation on ultrasound, making ultrasound superior for detecting retained wooden objects. Glass, metal, and stones are better visualized with CT due to their high radiodensity.

According to AIUM and musculoskeletal ultrasound literature:

“Wood is poorly visualized on CT but demonstrates high reflectivity and acoustic shadowing on ultrasound.”