Pass the ARDMS RDMS AB-Abdomen Questions and answers with CertsForce

The ultrasound image demonstrates a transverse view of the abdominal vasculature, where the arrow is pointing to a circular vascular structure anterior to the aorta and posterior to the body of the pancreas — consistent with the superior mesenteric artery (SMA).

The SMA originates from the anterior aspect of the abdominal aorta just below the level of the celiac trunk and courses anterior to the left renal vein and uncinate process of the pancreas. On transverse ultrasound, it is often seen in cross-section as a round, pulsatile structure with echogenic walls, situated just anterior to the aorta. This appearance is known as the “target sign” or “bull's-eye” appearance.

Vessel Position Landmarks (transverse plane):

Aorta: Posterior and central

SMA: Just anterior to the aorta

Left renal vein: Passes between the aorta and SMA (nutcracker location)

Right renal artery: Courses posterior to the IVC toward the right kidney

Differentiation from other options:

A. Proper hepatic artery: Typically visualized within the liver hilum (portal triad), not in this anatomic location.

C. Left renal vein: Seen in transverse as a longer, oval structure crossing anterior to the aorta and posterior to the SMA.

D. Right renal artery: Arises laterally from the aorta and courses posterior to the IVC — not visualized in this axial midline location.

A complex pleural effusion often contains internal septations or fibrin strands, distinguishing it from simple anechoic effusion. These septations suggest exudative processes such as infection, malignancy, or hemothorax.

According to Rumack’s Diagnostic Ultrasound:

“Complex pleural effusions demonstrate internal septations or loculations, often related to infection or malignancy.”

The ultrasound image shows a classic longitudinal view of a markedly thickened pyloric muscle with an elongated pyloric channel. This finding is consistent with hypertrophic pyloric stenosis (HPS), a condition most commonly seen in male infants between 2 and 8 weeks of age.

The most characteristic clinical finding associated with HPS is an “olive-shaped” palpable mass in the right upper quadrant or epigastric region, which represents the hypertrophied pylorus.

Clinical presentation of HPS includes:

Non-bilious projectile vomiting (due to gastric outlet obstruction)

Dehydration and weight loss

A palpable “olive” mass on physical exam

Visible peristalsis may be noted on the abdominal wall

Sonographic diagnostic criteria for HPS:

Pyloric muscle thickness ≥ 3 mm

Pyloric channel length ≥ 15–17 mm

“Cervix sign” or “target sign” (transverse view)

Failure of gastric contents to pass through the pylorus on real-time imaging

Differentiation from other options:

B. Fever of unknown origin: Not characteristic of HPS.

C. Red currant jelly stools: Classic for intussusception.

D. Bilious vomiting: Seen in distal duodenal or jejunal obstruction, not in pyloric stenosis (vomiting is non-bilious in HPS).

The ultrasound image demonstrates diffuse increased echogenicity of the liver parenchyma with posterior beam attenuation (acoustic shadowing), findings that are consistent with hepatic steatosis (fatty liver disease). The liver appears brighter than normal, and the vascular markings, particularly of the portal veins, are obscured due to the increased parenchymal echogenicity.

Hepatic steatosis refers to the abnormal accumulation of fat within hepatocytes and is commonly associated with obesity, diabetes, alcohol use, and metabolic syndrome.

Classic sonographic features of hepatic steatosis include:

Diffuse hyperechogenicity (“bright liver”)

Poor visualization of intrahepatic vessels and diaphragm

Posterior acoustic attenuation

Increased hepatic echogenicity relative to the renal cortex

Differentiation from other options:

A. Acute hepatitis: Usually presents with normal or slightly decreased echogenicity, "starry sky" appearance due to prominent portal triads and periportal edema.

C. Medullary sponge kidney: A renal condition with echogenic medullary pyramids, not hepatic.

D. Acute medical renal disease: Affects the kidneys, often with bilateral renal enlargement and increased cortical echogenicity—again not related to liver imaging.

The ultrasound image labeled “SAG LT KIDNEY MID” demonstrates a left kidney with two separate, centrally located echogenic renal sinuses separated by intervening renal parenchyma. This appearance is classic for a duplicated collecting system.

A duplicated collecting system (also known as duplex kidney) is a congenital anomaly in which a single kidney contains two separate pelvicalyceal systems. It may be complete (with two ureters) or incomplete (partial duplication of ureters). This condition is one of the most common congenital anomalies of the urinary tract.

Sonographic Features of a Duplicated Collecting System:

Two separate central echogenic renal sinus regions seen within one kidney

Intervening parenchyma between the two sinuses

May show associated findings: hydroureteronephrosis (especially of upper pole moiety), ureterocele

Best visualized in sagittal plane

Differentiation from other options:

A. Horseshoe kidney: Shows fusion of the lower poles of the kidneys, typically located anterior to the aorta in the midline—not demonstrated here.

B. Crossed renal ectopia: One kidney is located on the opposite side of the body; this image shows a normally positioned kidney.

C. Prominent renal column (column of Bertin): May mimic a mass, but does not produce two separate sinuses as shown here.

The normal hepatic vein Doppler waveform is triphasic, reflecting cardiac cycle variations in central venous pressure transmitted from the right atrium through the IVC. Loss of triphasicity may suggest elevated right atrial pressures or hepatic venous obstruction.

According to Rumack’s Diagnostic Ultrasound:

“The normal hepatic vein waveform is triphasic due to transmitted right atrial pressure variations.”

The tunica albuginea is a dense fibrous capsule surrounding the testis. Discontinuity of the tunica albuginea on ultrasound is diagnostic of testicular rupture — a urologic emergency that requires immediate surgical repair to preserve testicular function and viability. Early surgical intervention within 72 hours has a high success rate for testicular salvage (up to 90%).

Intratesticular hematoma (A) may be managed conservatively if the tunica albuginea is intact.

Heterogeneity of the parenchyma (C) indicates injury but not necessarily rupture.

Increased vascularity (D) may be seen with inflammation or reperfusion but does not mandate surgery unless rupture is present.

Reference Extracts:

Dogra VS, Bhatt S. "Acute painful scrotum: ultrasound evaluation." Radiologic Clinics of North America. 2004; 42(2):349-363.

Middleton WD, Kurtz AB, Hertzberg BS.Ultrasound: The Requisites. 3rd ed. Elsevier, 2015.

—

Type I choledochal cyst, characterized by fusiform dilatation of the common bile duct, is the most common form, accounting for 80-90% of cases. Other types are much less frequent.

According to Rumack’s Diagnostic Ultrasound:

“Type I fusiform dilatation of the extrahepatic bile duct is the most common type of choledochal cyst.”

In biliary obstruction (such as at the ampulla of Vater), dilation begins proximally and progresses peripherally. The intrahepatic peripheral bile ducts are the last to dilate because backpressure takes time to propagate. Early dilation is typically seen in the common bile duct and common hepatic duct.

According to Rumack’s Diagnostic Ultrasound:

“The intrahepatic peripheral bile ducts dilate last in the setting of progressive biliary obstruction.”

The arrow in this Doppler ultrasound image of the kidney is pointing to vessels located at the corticomedullary junction, arching over the bases of the medullary pyramids. This vascular pattern is characteristic of the arcuate arteries.

Renal arterial anatomy follows a specific branching hierarchy:

Segmental arteries branch off the main renal artery.

Interlobar arteries travel between renal pyramids.

Arcuate arteries arch over the base of the pyramids at the corticomedullary junction.

Interlobular arteries extend into the cortex from the arcuate arteries.

Key characteristics of arcuate arteries on ultrasound:

Located at the corticomedullary junction (between the medullary pyramids and renal cortex).

Run perpendicular to the long axis of the kidney, often forming an arching or curving pattern.

Commonly targeted in Doppler studies to assess resistive index (RI) in renal perfusion studies.

Comparison of answer choices:

A. Interlobular arteries are smaller vessels that extend perpendicularly from the arcuate arteries into the cortex—not visible at this level.

B. Arcuate — Correct. The arrow is indicating these vessels arching over the medullary pyramids.

C. Segmental arteries are larger and deeper, branching off the renal artery near the hilum.

D. Interlobar arteries course between the pyramids but do not arch along their base.