Which abnormality is depicted in this image of a patient who presents with a fever following a liver biopsy?
Correct Answer: C
The sonographic image shows a complex fluid collection within the liver parenchyma, with internal echoes and possibly septations, consistent with an abscess. In the clinical context of post-procedural fever following a liver biopsy, a liver abscess is the most likely diagnosis. A liver abscess appears on ultrasound as a hypoechoic or complex fluid collection that may contain internal debris, septations, or gas (which may produce reverberation artifacts). These features distinguish it from other post-procedural complications. * A cyst (Option A) typically appears as an anechoic, well-defined lesion with posterior acoustic enhancement and no internal debris-this does not match the image or clinical setting. * A biloma (Option B) is a bile collection that can appear similar to a cyst or fluid collection but typically occurs due to bile leak; however, fever and internal complexity on ultrasound more strongly suggest abscess. * A hematoma (Option D) may also appear complex but usually presents with pain and not fever unless secondarily infected. Over time, hematomas evolve in appearance but lack septations and gas unless superinfected. Reference: Rumack, Carol M., et al. Diagnostic Ultrasound.5th ed., Elsevier, 2018. Chapter: Hepatobiliary System, pp. 107-111. American Institute of Ultrasound in Medicine (AIUM) Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.
Question 27
Which vessel is located directly proximal to the origination of the renal arteries?
Correct Answer: D
The renal arteries originate from the abdominal aorta just inferior to the superior mesenteric artery (SMA). The SMA arises anteriorly from the abdominal aorta at the level of L1, and just below it, the renal arteries branch laterally. The splenic vein, portal vein, and hepatic artery are located more superiorly in relation to the renal arteries. According to Moore's Clinically Oriented Anatomy: "The superior mesenteric artery arises from the anterior surface of the abdominal aorta just above the renal arteries." (Moore KL et al., Clinically Oriented Anatomy, 8th ed.) Reference: Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy. 8th ed. Wolters Kluwer, 2018. Gray's Anatomy for Students, 4th ed., Elsevier, 2019.
Question 28
What is the most common cause of nutcracker syndrome?
Correct Answer: B
Nutcracker syndrome results from compression of the left renal vein between the superior mesenteric artery (SMA) and the aorta. This can cause hematuria, flank pain, and pelvic congestion due to impaired venous drainage. According to Zwiebel's Introduction to Vascular Ultrasound: "In nutcracker syndrome, the left renal vein is compressed between the aorta and SMA, resulting in venous hypertension." Reference: Zwiebel WJ, Pellerito JS. Introduction to Vascular Ultrasound. 6th ed. Elsevier, 2019. AIUM Practice Parameter for Abdominal Vascular Ultrasound, 2020. -
Question 29
Which adjustment would most likely improve visualization of a small superficial tubular structure such as a peripheral artery?
Correct Answer: C
Reducing slice (section) width improves spatial resolution, particularly elevational resolution, which enhances visualization of small, superficial structures. Lower slice width reduces off-axis beam artifacts and blurring. Wavelength depends on transducer frequency, not adjustable directly during scanning. According to Zwiebel's Introduction to Vascular Ultrasound: "Reduction in slice thickness improves imaging of small superficial structures by minimizing volume averaging and improving elevational resolution." Reference: Zwiebel WJ, Pellerito JS. Introduction to Vascular Ultrasound. 6th ed. Elsevier, 2019. AIUM Practice Parameter for Vascular Ultrasound, 2021. -
Question 30
Which sonographic finding is most consistent with this image of the abdominal aorta?
Correct Answer: C
The ultrasound image provided shows a transverse view of the abdominal aorta, with a clearly measured aortic diameter of 5.71 cm. A normal adult abdominal aorta should measure less than 3.0 cm in anterior- posterior diameter. Any measurement exceeding this threshold is defined as an abdominal aortic aneurysm (AAA). In this case, the dilation is well beyond the 3.0 cm threshold, confirming the presence of an aneurysm. The rounded, anechoic/heterogeneous central lumen surrounded by echogenic arterial wall layers further supports this diagnosis. Comparison of answer choices: * A. Stenosis: Would show a narrowed lumen with turbulent, aliasing flow on Doppler, not a dilated aorta. * B. Dissection: Typically shows an echogenic intimal flap separating true and false lumens; no flap is visible here. * C. Aneurysm: Correct. The aorta's transverse diameter (5.71 cm) confirms the presence of an aneurysm. * D. Occlusion: Would appear as a lack of flow with thrombus or echogenic content filling the lumen, not dilation. References: Rumack CM, Wilson SR, Charboneau JW, Levine D. Diagnostic Ultrasound, 5th ed. Elsevier; 2017. Society for Vascular Surgery Guidelines: Management of Abdominal Aortic Aneurysms (Chaikof et al., J Vasc Surg, 2018). Hagen-Ansert SL. Textbook of Diagnostic Sonography, 8th ed. Elsevier; 2017.
