AB-Abdomen ARDMS Abdomen Sonography Examination Free Practice Exam Questions (2025 Updated)

The spleen is suspended in the left upper quadrant by several peritoneal ligaments, including:

Lienorenal (splenorenal) ligament — attaches spleen to the left kidney.

Gastrosplenic ligament — attaches spleen to the stomach.

Phrenocolic ligament — supports the spleen inferiorly between diaphragm and colon.

These ligaments stabilize the spleen’s position while allowing some mobility.

According to Moore’s Clinically Oriented Anatomy:

“The spleen is connected to the stomach by the gastrosplenic ligament and to the posterior abdominal wall (near the left kidney) by the splenorenal (lienorenal) ligament. The phrenocolic ligament provides inferior support.”

The CT and ultrasound images show a lenticular-shaped, hypoechoic fluid collection compressing the renal parenchyma from the periphery. The location—between the renal capsule and the renal parenchyma—strongly suggests a subcapsular hematoma.

Subcapsular hematomas in transplant kidneys are uncommon but important postoperative complications, often resulting from trauma, biopsy, or surgical manipulation. They typically present as a crescent-shaped, low-attenuation collection beneath the renal capsule and may cause mass effect on the underlying renal parenchyma. This can impair renal perfusion and function—a phenomenon known as “Page kidney.”

Ultrasound findings:

Anechoic to hypoechoic, crescent-shaped collection surrounding or compressing the transplant kidney.

Deformation or flattening of the renal contour due to the compressive effect of the hematoma.

CT findings:

Hyperdense collection (if acute) or hypodense (if subacute/chronic) located subcapsularly.

May be seen distorting the renal capsule and compressing renal tissue.

Differentiation from other options:

A. Urinoma: Typically appears as a perinephric fluid collection and may result from urine leak. Not usually subcapsular.

B. Lymphocele: Develops in the post-transplant period due to lymphatic disruption. Appears as a well-defined perinephric fluid collection and tends to be medial to the kidney or between the bladder and the kidney.

C. Renal cell carcinoma: Would appear as a solid mass with variable enhancement and not a simple fluid collection. RCC is rare in transplant kidneys and usually detected much later post-transplant.

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.

The ultrasound image clearly demonstrates a thickened and elongated pyloric muscle with a visible channel, which is characteristic of hypertrophic pyloric stenosis (HPS). This condition is most commonly seen in male infants between 2 and 8 weeks of age who present with non-bilious projectile vomiting, dehydration, and a palpable “olive-like” mass in the right upper quadrant.

Ultrasound is the imaging modality of choice and is highly sensitive and specific for diagnosing pyloric stenosis.

Key sonographic criteria for HPS:

Muscle thickness >3 mm

Pyloric channel length >15–17 mm

“Target sign” or “doughnut sign” on transverse imaging (concentric rings)

“Cervix” or “railroad track sign” on longitudinal imaging (elongated canal with echogenic center)

Differentiation from other options:

A. Intussusception: Also shows a target sign, but it occurs in the right lower quadrant or periumbilical region, not in the gastric antrum.

C. Hydronephrosis: Refers to dilation of the renal pelvis and calyces — not gastrointestinal.

D. Gastritis: May show gastric wall thickening but lacks the distinct elongated, thickened pyloric muscle seen here.

The ultrasound images (sagittal and transverse views of the left kidney) demonstrate a large, well-defined, heterogeneous mass within the renal parenchyma. This is highly characteristic of renal cell carcinoma (RCC), the most common primary renal malignancy in adults.

Renal cell carcinoma accounts for approximately 85% of all malignant renal tumors in adults. RCC often appears as:

A solid, heterogeneous, hypoechoic to isoechoic mass within the kidney

May contain areas of necrosis or hemorrhage (seen as mixed echogenicity)

Distortion of the normal renal contour

May have internal vascularity on Doppler imaging

Clear cell carcinoma (choice B) is the most common histological subtype of RCC but is not a separate diagnosis from RCC in imaging terms. Therefore, the most accurate answer is choice C: Renal cell carcinoma.

Differentiation from other options:

A. Nephroblastoma (Wilms tumor): A pediatric renal tumor, typically seen in children under 5 years of age—not applicable in adults.

B. Clear cell carcinoma: Histological subtype of RCC, not a distinct radiologic diagnosis.

D. Transitional cell carcinoma: Arises from the renal pelvis or ureter, typically appears as a central or collecting system mass rather than a cortical/parenchymal one.

A normal renal artery waveform demonstrates rapid systolic upstroke (acceleration) with continuous forward flow in diastole due to the kidney's low-resistance vascular bed. Slow acceleration or blunted peaks may indicate significant renal artery stenosis.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Normal renal artery waveforms demonstrate a rapid systolic acceleration with a sharp systolic peak.”

The image provided is a right upper quadrant (RUQ) ultrasound—typically performed during a FAST (Focused Assessment with Sonography in Trauma) exam or for abdominal assessment. The arrow points to an anechoic (black) fluid collection seen above the diaphragm and posterior to the liver.

This fluid collection lies within the thoracic cavity, confirming the diagnosis of a pleural effusion. Pleural effusions are seen sonographically as an anechoic or hypoechoic area superior to the diaphragm in the thoracic cavity and often appear triangular or crescent-shaped. The diaphragm is visualized as a curvilinear echogenic structure separating the liver (or spleen) below from the lung space above.

Comparison of answer choices:

A. Retroperitoneal hemorrhage would be seen in the posterior abdomen, not above the diaphragm.

B. Pleural effusion is correct—anechoic fluid above the diaphragm is classic for this condition.

C. Mirror image artifact occurs when liver echoes are mirrored across the diaphragm and lung—this is not a mirror artifact.

D. Ascites collects inferior to the diaphragm and around the abdominal organs, not in the thoracic cavity.

The most serious long-term complication of undescended testis (cryptorchidism) is an increased risk of testicular malignancy, especially seminoma. Although torsion and hernia may also occur, seminoma is the most concerning complication due to its life-threatening potential.

According to Rumack’s Diagnostic Ultrasound:

“Cryptorchidism is associated with a significantly increased risk of seminoma, the most common malignancy in undescended testes.”

A varicocele is an abnormal dilatation of the pampiniform plexus veins, usually seen on the left side due to the perpendicular insertion of the left testicular vein into the left renal vein, making it more susceptible to elevated venous pressure. Sonographically, varicoceles appear as multiple serpiginous anechoic tubular structures that show venous flow on color Doppler, often accentuated with Valsalva maneuver.

Hydrocele (A) is a fluid collection surrounding the testis.

Hematocele (C) is blood within the tunica vaginalis.

Spermatocele (D) is a cystic lesion arising from the epididymis.

Reference Extracts:

Dogra VS, Bhatt S. "Sonographic evaluation of testicular varicoceles." Journal of Ultrasound in Medicine. 2004;23(6): 829-838.

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

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The clinical presentation—tender, swollen breast with erythema and fever—in a lactating female strongly suggests acute mastitis. The sonographic findings support this diagnosis. In the image, the breast parenchyma shows diffuse, hypoechoic, and heterogeneous echotexture with increased vascularity, which is consistent with inflammatory changes typical of mastitis.

Mastitis is a common complication during lactation, particularly in the first few weeks postpartum. It results from milk stasis and subsequent bacterial infection, commonly due to Staphylococcus aureus. Ultrasound features of mastitis include:

Ill-defined, hypoechoic, edematous areas in the breast parenchyma

Increased Doppler flow due to hyperemia

Skin thickening

Ductal dilatation may also be present

If left untreated, mastitis may progress to abscess formation, which would appear as a localized, complex fluid collection with peripheral hyperemia and internal debris. However, the image does not show a well-formed fluid collection consistent with abscess.

Option B (Ductal carcinoma): Inappropriate here due to the acute clinical scenario and patient age. Ductal carcinoma typically presents as a hypoechoic mass with irregular margins and posterior shadowing, not diffuse edema or inflammatory changes.

Option D (Galactocele): This benign milk-filled retention cyst typically appears anechoic or with fluid–fluid levels but lacks signs of inflammation and systemic symptoms such as fever.

Option A (Abscess): This could be a differential, but abscesses usually present with a well-defined anechoic or complex mass. The absence of a discrete collection and the diffuse appearance makes mastitis more likely.

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 normal gallbladder wall measures up to 3 mm. Thickening beyond 3 mm may suggest cholecystitis, heart failure, hepatitis, or hypoalbuminemia. Measurements should be taken with the patient fasting, using the anterior gallbladder wall.

According to Rumack’s Diagnostic Ultrasound:

“The gallbladder wall is considered thickened if it measures greater than 3 mm.”

The ultrasound image demonstrates a longitudinal view of the right kidney. Within the renal pyramids, there are multiple echogenic foci, some showing posterior acoustic shadowing—findings characteristic of medullary nephrocalcinosis. This sonographic appearance is strongly associated with medullary sponge kidney (MSK).

Medullary sponge kidney is a congenital disorder of the renal tubules that results in ectatic (dilated) collecting ducts in the renal medulla. The dilated ducts frequently become calcified, leading to the "paintbrush" or "bouquet of flowers" appearance seen in the renal pyramids on ultrasound. These calcifications are most often bilateral and symmetrical, further aiding the diagnosis.

Comparison of answer choices:

A. Fungal balls (mycetomas) typically appear as mobile, non-shadowing echogenic masses within the collecting system, often in immunocompromised patients.

B. Renal cell carcinoma usually presents as a solid mass with irregular borders and variable echogenicity—this image does not show a mass.

C. Acute pyelonephritis may show renal enlargement, decreased echogenicity, or loss of corticomedullary differentiation—but not calcification of the pyramids.

D. Medullary sponge kidney is correct due to the punctate echogenic foci within the medullary pyramids, consistent with nephrocalcinosis.

Splenosis refers to autotransplantation of splenic tissue following splenic trauma or splenectomy. After rupture, splenic fragments may implant throughout the peritoneal cavity and vascularize, forming multiple nodules of functional splenic tissue. Splenosis is typically asymptomatic and discovered incidentally on imaging.

Splenule (A) is a congenital accessory spleen, not related to trauma.

Hamartoma (C) is a benign primary splenic lesion.

Target lesion (D) generally refers to sonographic appearance seen in metastases or infections, not post-trauma.

Reference Extracts:

Mortelé KJ, et al. "Multimodality imaging of splenic lesions and the spleen." Radiographics. 2004;24(4):1137-1163.

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

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Courvoisier sign describes the clinical finding of painless jaundice combined with a palpable, distended gallbladder. This typically results from obstruction at the distal common bile duct, often due to pancreatic head carcinoma or cholangiocarcinoma, leading to bile accumulation and gallbladder distention. In contrast, Mirizzi syndrome involves compression of the common hepatic duct by an impacted stone in the cystic duct.

According to Rumack's Diagnostic Ultrasound and standard clinical references:

“Courvoisier sign refers to a palpable, enlarged gallbladder due to obstruction of the distal bile duct, often from malignancy.”

The ultrasound image shows a classic “target sign” or “donut sign,” characterized by concentric rings of alternating echogenicity. This sonographic finding is pathognomonic for intussusception, particularly when seen in the transverse plane.

Intussusception occurs when a segment of bowel telescopes into an adjacent segment, typically in children aged 6 months to 3 years. It commonly presents with intermittent abdominal pain, vomiting, and sometimes “red currant jelly” stools.

Key ultrasound features of intussusception:

Target sign in transverse view (concentric rings of bowel layers)

Pseudokidney or sandwich sign in longitudinal view

May show intraluminal mesenteric fat or vessels dragged in with the intussusceptum

Comparison of answer choices:

A. Bowel obstruction may show dilated loops of bowel with air-fluid levels and to-and-fro peristalsis but lacks the concentric ring sign.

B. Diverticulitis typically shows bowel wall thickening and pericolic fat stranding; not the concentric target appearance.

C. Appendicitis may appear as a blind-ending tubular structure (>6 mm), not with concentric ring pattern.

D. Intussusception — Correct. The image demonstrates the classic target sign seen with this condition.

The main renal vein should be assessed in addition to the renal arteries during renal Doppler exams. Venous thrombosis may coexist with arterial abnormalities and can impact renal perfusion. Evaluation of both arterial inflow and venous outflow ensures a comprehensive assessment of renal vascular patency.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Renal vein assessment should be performed during renal artery Doppler studies to exclude venous thrombosis or outflow obstruction.”

The ultrasound image reveals a well-defined, anechoic (black), thin-walled fluid collection located in the subcutaneous or parenchymal plane of the breast. This is most consistent with a seroma, particularly in the context of recent breast surgery.

A seroma is a common postsurgical finding, representing a sterile collection of serous fluid that accumulates in the surgical bed. It typically appears:

Anechoic (or hypoechoic if older)

Well circumscribed

Without internal septations or debris

Lacking hyperemia or surrounding inflammatory changes

This contrasts with:

A. Carcinoma — typically presents as an irregular, hypoechoic mass with angular margins, internal vascularity, and shadowing.

B. Blood clot (hematoma) — often appears heterogeneous, with internal echoes and variable echotexture depending on the age of the clot.

C. Abscess — appears as a complex fluid collection with thick walls, internal debris, septations, and surrounding hyperemia (often with clinical signs of infection).

D. Seroma — Correct. The described anechoic, clean-walled fluid collection is classic for a postoperative seroma.

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.