RDMS AB-Abdomen ARDMS Study Notes

The hallmark feature of focal nodular hyperplasia (FNH) is a central stellate scar seen on imaging. This fibrous scar may not always be seen on ultrasound but is a classic distinguishing feature from hepatic adenomas, which usually lack a central scar.

According to Rumack’s Diagnostic Ultrasound:

“Focal nodular hyperplasia often demonstrates a central stellate scar, which may be echogenic or isoechoic.”

Scrotal inflammation, such as epididymitis or orchitis, typically presents with increased blood flow (hyperemia) on color Doppler sonography. This finding reflects the inflammatory process and vascular dilation. Abscesses, granulomas, or hydroceles may be present but are not as consistent or specific for inflammation.

According to AIUM Practice Parameters and Rumack’s Diagnostic Ultrasound:

“In acute inflammation, color Doppler ultrasound demonstrates prominent hyperemia of the epididymis or testis.”

Graded compression technique is the gold standard for ultrasound evaluation of the appendix. It displaces gas and compresses overlying bowel loops to visualize the noncompressible, blind-ending tubular appendix directly at the point of maximal tenderness.

According to Rumack’s Diagnostic Ultrasound:

“Graded compression using steady, increasing pressure displaces gas and bowel to optimize visualization of the appendix.”

A full bladder provides an acoustic window that displaces bowel gas and distends the bladder walls, allowing optimal visualization of any bladder masses or lesions. An empty bladder may collapse, obscuring masses.

According to Rumack’s Diagnostic Ultrasound:

“Bladder evaluation should be performed with the bladder optimally distended to visualize its walls and any intraluminal masses.”