AB-Abdomen Abdomen Sonography Examination Questions and Answers

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.”

Hepatitis A is primarily transmitted via the fecal-oral route, often through contaminated food or water. Hepatitis B, C, and D are transmitted through blood and body fluids.

According to CDC and WHO guidelines:

“Hepatitis A virus (HAV) is transmitted primarily by the fecal-oral route via ingestion of contaminated food or water.”

The ultrasound image shows a hypoechoic, round structure with internal microcalcifications — hallmarks of recurrent papillary thyroid carcinoma (PTC) metastasis in a lymph node.

Key sonographic features supporting recurrent papillary thyroid cancer:

Hypoechoic round lymph node (loss of normal oval shape and hilum)

Microcalcifications (punctate echogenic foci) – highly suggestive of metastatic PTC

Abnormal morphology (loss of fatty hilum, rounded shape, increased vascularity if Doppler used)

Seen in the thyroid bed or lateral neck post-thyroidectomy

Why the other options are incorrect:

B. Normal postsurgical lymph node – Would be oval with echogenic hilum and no microcalcifications

C. Residual glandular tissue – Would have a more homogeneous echotexture similar to thyroid tissue and be located at the thyroid bed, not necessarily nodal

D. Reactive lymph node – May be enlarged but retain a normal hilum and vascular pattern, and lack microcalcifications

Littoral cell angioma is a rare, benign vascular tumor of the spleen, arising from the littoral cells lining the splenic sinusoids. In contrast, lymphoma, metastasis, and angiosarcoma are malignant splenic neoplasms.

According to WHO Classification and Rumack’s Diagnostic Ultrasound:

“Littoral cell angioma is a rare benign vascular neoplasm of the spleen with characteristic imaging findings.”

The ultrasound image demonstrates a complex, heterogeneous hypoechoic collection within the abdominal wall, with mixed echogenicity and ill-defined margins. The lesion appears to contain internal debris but lacks definitive signs of vascularity or air (which would be seen in an abscess). There is no peristalsis, herniated bowel, or fat to suggest hernia.

Given the history of atrial fibrillation — a condition commonly treated with anticoagulation therapy (e.g., warfarin, apixaban) — this clinical background raises high suspicion for a rectus sheath or abdominal wall hematoma.

Key ultrasound features of hematomas:

Early (acute): hyperechoic or heterogeneous

Chronic/resolving: complex or cystic with fluid-debris levels

No internal vascularity on Doppler

May be confined to muscle or fascial planes

This is consistent with a hematoma, particularly in patients on anticoagulation therapy.

Comparison of answer choices:

A. Hernia — typically shows bowel or fat with movement/peristalsis passing through a fascial defect.

B. Lipoma — usually homogeneous and echogenic, not complex or fluid-filled.

C. Abscess — often presents as a complex fluid collection with peripheral hyperemia and possibly air, plus systemic signs of infection.

D. Hematoma — Correct. The image and clinical history (anticoagulation due to atrial fibrillation) strongly support this diagnosis.

The transverse ultrasound image of the liver shows a solid, hypoechoic mass located in the posterior aspect of the right lobe of the liver. In this view:

The anterior aspect of the liver is at the top of the image (near the transducer).

The posterior aspect is at the bottom (deeper).

The right lobe occupies the majority of the screen on transverse imaging when the probe is placed in the epigastrium or right upper quadrant.

Anatomically, the right lobe of the liver is divided into anterior and posterior segments by the right hepatic vein in the coronal plane. In transverse imaging:

The right anterior segment lies closer to the anterior abdominal wall.

The right posterior segment lies deeper (posteriorly).

Given that the mass is seen deep within the liver on the right side of the image, it is best localized to the right posterior segment (Segment VI or VII depending on the exact craniocaudal level).

Comparison of answer choices:

A. Left lateral is located far to the left of the image and typically appears higher and more anterior on transverse scans.

B. Left medial lies near the midline and would appear adjacent to the ligamentum teres or falciform ligament.

C. Right anterior lies closer to the transducer (top of the image), not posteriorly.

D. Right posterior — Correct. This is the segment shown deep in the right lobe of the liver.

The ultrasound image shows a measured common bile duct (CBD) diameter of 7.9 mm in a postcholecystectomy patient. In patients who have undergone cholecystectomy, mild dilation of the CBD is considered normal and is a well-recognized post-surgical change.

Normal upper limits for CBD diameter:

In patients with a gallbladder: ≤6 mm is generally considered normal.

In postcholecystectomy patients: up to 10 mm is considered within normal limits, as the CBD compensates for the absence of the gallbladder and slightly enlarges over time.

With aging, the CBD may enlarge by approximately 1 mm per decade after age 60.

Therefore, a CBD diameter of 7.9 mm in a patient without a gallbladder is considered normal.

Differentiation from other options:

B. Dilated: This would typically refer to a CBD diameter >10 mm in postcholecystectomy patients, or >6 mm in patients with an intact gallbladder.

C. Inflamed: Inflammation refers to wall thickening or hyperemia, which is not evaluated simply by measuring diameter.

D. Atretic: Describes a congenitally absent or severely narrowed duct — not applicable here.

The ultrasound image demonstrates a heterogeneous and echogenic spleen with evidence of atrophy and multiple areas of calcification—consistent with autosplenectomy. This appearance is classically associated with chronic sickle cell anemia.

In sickle cell disease, repeated vaso-occlusive episodes result in infarctions, fibrosis, and progressive calcification of the spleen. Over time, this leads to functional asplenia or complete autosplenectomy (involution and shrinkage of the spleen). The hallmark sonographic features include:

A small, echogenic spleen

Multiple coarse calcifications

Irregular contour or atrophic appearance

These findings are not typically seen in other conditions:

A. Trauma may cause subcapsular hematomas or lacerations, but not chronic atrophy with calcifications.

C. Immunocompromised patients may develop abscesses or infections but not the classic features of autosplenectomy.

D. Portal hypertension typically causes splenomegaly and varices, not atrophic and calcified spleens.

In mild acute pancreatitis, the pancreas often appears diffusely enlarged and slightly hypoechoic due to edema and inflammation. However, in very early or mild cases, the pancreas may still appear normal. Heterogeneous echotexture may develop in more severe or necrotizing pancreatitis.

According to Rumack’s Diagnostic Ultrasound:

“In mild pancreatitis, the pancreas is commonly enlarged and hypoechoic due to inflammatory edema.”

The ultrasound image demonstrates a well-defined, ovoid, hypoechoic to isoechoic mass within the subcutaneous tissue of the abdominal wall. The lesion appears compressible and shows linear striations parallel to the skin surface — a classic appearance of a lipoma.

Lipomas are the most common benign soft tissue tumors and frequently arise in the subcutaneous tissue. They are composed of mature adipose tissue and are typically asymptomatic unless large or compressing adjacent structures.

Sonographic features of a lipoma:

Isoechoic to mildly hyperechoic or hypoechoic relative to subcutaneous fat

Oval or elliptical in shape with well-defined margins

Internal linear striations or “feathered” echotexture

Compressible and non-vascular on Doppler imaging

Located in subcutaneous fat plane parallel to the skin surface

Differentiation from other options:

B. Fibroma: Typically appears as a homogeneous, hypoechoic mass but is far less common in the abdominal wall.

C. Desmoid: Appears as an ill-defined or infiltrative mass within deeper soft tissues; more heterogeneous and may distort surrounding tissue planes.

D. Metastasis: Often more irregular, heterogeneous, and may show increased vascularity or invasion into adjacent structures.

Tissue harmonic imaging significantly reduces reverberation and side-lobe artifacts by utilizing nonlinear propagation of ultrasound waves. This produces clearer images of fluid-filled structures like the gallbladder, improving visualization of wall thickness and intraluminal contents.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Harmonic imaging effectively reduces reverberation artifact, improving image quality in gallbladder and cystic structure evaluation.”

Budd-Chiari syndrome is caused by hepatic venous outflow obstruction, resulting in hepatomegaly, ascites, right upper quadrant pain, and liver dysfunction. It may be due to thrombosis or compression of the hepatic veins or IVC.

According to Rumack’s Diagnostic Ultrasound:

“Budd-Chiari syndrome results from hepatic venous outflow obstruction and presents with hepatomegaly, ascites, and right upper quadrant pain.”

The correct sequence of renal arterial branching is: renal artery → segmental arteries → interlobar arteries → arcuate arteries → interlobular arteries. This branching pattern is important for understanding renal perfusion and evaluating vascular disorders.

According to Moore’s Clinically Oriented Anatomy:

“Renal arteries divide into segmental branches, which give rise to interlobar arteries, then arcuate arteries, and finally interlobular arteries.”

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.

Alpha-fetoprotein (AFP) is commonly elevated in patients with hepatocellular carcinoma (hepatoma), particularly in those with underlying cirrhosis or chronic hepatitis B/C. AFP is not typically elevated in adenomas, cholangiocarcinoma, or FNH.

According to Rumack’s Diagnostic Ultrasound:

“Serum AFP levels are elevated in 50–70% of patients with hepatocellular carcinoma.”

A thyroglossal duct cyst is the most common congenital cystic anomaly in the anterior midline neck. It arises from persistent remnants of the thyroglossal duct, typically located inferior to the hyoid bone.

According to Rumack’s Diagnostic Ultrasound:

“Thyroglossal duct cysts are located in the midline anterior neck and are the most common congenital cystic neck lesions.”

Power Doppler measures the amplitude (strength) of Doppler signals rather than frequency shift, making it more sensitive to low-velocity and small-vessel blood flow. Its primary advantage is an improved signal-to-noise ratio, allowing for better visualization of slow or weak flow.

A: Power Doppler is more sensitive to motion artifacts, not less.

B: It is still angle dependent, though somewhat less so than color Doppler.

D: Power Doppler does not display flow direction (a limitation).

Reference Extracts:

Kremkau FW. Sonography Principles and Instruments. 9th ed. Elsevier, 2015.

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

Exudative ascites is characterized by high protein content and cellular debris, typically resulting from infections (e.g., peritonitis, tuberculosis), malignancy, or inflammatory conditions. Transudative ascites is more commonly seen in conditions such as liver failure, renal failure, and hypoproteinemia due to changes in hydrostatic or oncotic pressure.

According to Light's Criteria:

“Infection and malignancy are common causes of exudative ascites, distinguished by high protein content and elevated LDH.”

The normal epididymis typically appears as a homogeneous structure that is either isoechoic or slightly hypoechoic compared to the testis. The most accurate description is "homogeneous compared to the testis," meaning the texture is uniform. It is not anechoic, nor does it typically show irregular borders unless pathology is present.

According to Rumack’s Diagnostic Ultrasound:

"The normal epididymis appears homogeneous and is isoechoic or slightly hypoechoic relative to the testis." (Rumack CM et al., Diagnostic Ultrasound, 5th ed.)

The Duct of Santorini is the accessory pancreatic duct that drains the superior portion of the pancreatic head into the minor duodenal papilla. The main pancreatic duct (Duct of Wirsung) drains into the major papilla, often joining the common bile duct at the Ampulla of Vater.

According to Moore’s Clinically Oriented Anatomy:

“The accessory pancreatic duct (Duct of Santorini) may be present and drains into the minor duodenal papilla.”

The ultrasound image labeled “SAG RUQ KIDNEY” demonstrates a midline sagittal view showing a renal parenchymal structure that extends across the midline anterior to the aorta and vertebral bodies, suggesting the presence of a horseshoe kidney.

A horseshoe kidney is a congenital renal anomaly in which the lower poles of both kidneys are fused across the midline by a parenchymal or fibrous isthmus. This isthmus typically lies anterior to the aorta and inferior vena cava and can be seen as a hypoechoic band of tissue crossing the midline on ultrasound.

Ultrasound findings characteristic of a horseshoe kidney:

Abnormally low position of the kidneys in the abdomen

Renal tissue (isthmus) bridging the lower poles anterior to the great vessels

Renal axes may be more horizontal than usual

Kidneys may appear closer together or “kissing” the spine anteriorly

Differentiation from other options:

A. Duplicated collecting system: Manifests as two separate collecting systems within one kidney, often with a central renal sinus split into two — not typically midline bridging.

B. Crossed renal ectopia: Involves one kidney crossing midline and fusing with the other on the opposite side, but they do not form a midline isthmus.

D. Pelvic kidney: A single kidney located in the pelvis due to failed ascent — it does not appear as midline fusion of two kidneys.

Addison disease (primary adrenal insufficiency) results in insufficient production of cortisol and aldosterone. The hallmark laboratory findings include:

Hyponatremia (low sodium)

Hyperkalemia (high potassium)

Elevated liver enzymes (due to nonspecific hepatic involvement)

Fatigue, weight loss, and hypotension are common clinical features.

Conn syndrome (B) causes hyperaldosteronism, leading to hypokalemia (not hyperkalemia).

Acute pancreatitis (C) would typically show elevated amylase/lipase.

Hepatocellular carcinoma (D) may present with elevated liver enzymes but not the electrolyte pattern described.

Reference Extracts:

Nieman LK. "Diagnosis and Treatment of Primary Adrenal Insufficiency." J Clin Endocrinol Metab. 2011;96(7):1957-1966.

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

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The spleen is almost entirely covered by visceral peritoneum, except at the hilum where vessels, nerves, and lymphatics enter and exit. This area lacks peritoneal covering to allow vascular connection to the splenic artery and vein.

According to Moore’s Clinically Oriented Anatomy:

“The spleen is entirely covered by visceral peritoneum except at its hilum where the vascular structures enter.”

Angiomyolipomas are benign renal tumors composed of fat, smooth muscle, and blood vessels. They are strongly associated with tuberous sclerosis and may be multiple and bilateral in these patients. While RCC may occur, angiomyolipomas are much more characteristic.

According to Rumack’s Diagnostic Ultrasound:

“Angiomyolipomas are frequently multiple and bilateral in patients with tuberous sclerosis.”

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.

The ultrasound image demonstrates a tubular, anechoic structure coursing anterior to the left portal vein and heading toward the anterior abdominal wall. This is consistent with a recanalized umbilical vein, which is an important collateral pathway that reopens in cases of portal hypertension.

Normally, the umbilical vein becomes obliterated after birth and forms the ligamentum teres. However, in the setting of significant portal hypertension, the umbilical vein may recanalize and serve as a collateral route to decompress the portal system.

Sonographic features of a recanalized umbilical vein:

Anechoic, tubular structure in the ligamentum teres fissure

Seen anterior to the left portal vein

Color Doppler confirms hepatofugal venous flow

Associated with signs of portal hypertension (e.g., splenomegaly, varices)

Differentiation from other options:

A. Budd-Chiari syndrome: Involves hepatic vein outflow obstruction; ultrasound shows absent or narrowed hepatic veins and may have caudate lobe hypertrophy.

B. Splenic artery aneurysm: Typically visualized near the splenic hilum as a pulsatile cystic mass; Doppler shows arterial flow.

D. Median arcuate ligament syndrome: Involves compression of the celiac axis; best assessed with Doppler showing elevated velocities on expiration.

Changing the patient's position allows evaluation of lesion mobility. Blood clots and hematomas are often mobile, while true bladder wall masses remain fixed. This technique helps differentiate between solid masses and non-adherent debris.

According to Rumack’s Diagnostic Ultrasound:

“Changing patient position may distinguish between mobile blood clots and fixed bladder wall masses.”

Chronic rejection presents sonographically as cortical thinning, decreased renal size, and increased echogenicity of the renal sinus fat. Acute rejection typically causes an enlarged, edematous kidney with increased parenchymal echogenicity but preserved size early on.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“In chronic rejection, the allograft becomes smaller with cortical thinning, increased echogenicity, and prominence of the central sinus fat.”

Most thyroid cancer recurrences are found in the ipsilateral neck—particularly in the central (level VI) or lateral (levels II-V) compartments on the same side as the original malignancy.

According to AIUM Practice Parameters:

“Post-thyroidectomy recurrence most frequently occurs ipsilateral to the original tumor, commonly involving regional lymph nodes.”

The grayscale ultrasound image demonstrates a uniformly enlarged, hypoechoic (dark), and heterogeneous testis without signs of surrounding scrotal wall thickening or a discrete fluid collection. This pattern is highly suggestive of testicular torsion in the setting of acute scrotal pain.

Sonographic features of testicular torsion on grayscale imaging:

Enlarged testis

Diffusely hypoechoic parenchyma

Loss of normal homogeneity

Absence of internal vascular flow on Doppler imaging (not shown here but critical in confirming diagnosis)

Testicular torsion occurs due to twisting of the spermatic cord, leading to vascular compromise and eventual infarction if not promptly corrected. It is a surgical emergency and typically presents in adolescent males with sudden-onset, severe unilateral testicular pain.

Comparison of answer choices:

A. Scrotal abscess appears as a complex fluid collection with irregular margins and posterior enhancement.

B. Testicular rupture would show discontinuity of the tunica albuginea, heterogeneous texture, and often a hematocele.

C. Testicular torsion — Correct. The enlarged, hypoechoic, heterogeneous testis is characteristic, particularly in the acute phase.

D. Epididymitis typically shows an enlarged, hypervascular epididymis and may extend to the testis (epididymo-orchitis), but vascularity is usually increased rather than absent.

An intimal flap in the aorta is a hallmark ultrasound finding of aortic dissection, which can present with tearing chest/abdominal pain and differential blood pressures between arms. The flap represents separation of the intimal and medial layers of the aortic wall.

According to Rumack’s Diagnostic Ultrasound:

“An intimal flap visualized within the aorta is diagnostic of an aortic dissection.”

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.

The spectral Doppler image demonstrates excessive noise along the baseline, including a “fuzzy” or filled-in spectral window. This artifact is known as spectral broadening or “blossoming,” and it typically results from excessive Doppler gain.

When Doppler gain is set too high, it amplifies not only the true Doppler signal but also the background noise. This results in a falsely broadened waveform that can obscure diagnostic information such as peak velocities or flow turbulence. The best way to correct this artifact is to reduce the Doppler gain (Option A).

Key points regarding gain-related artifact:

Excessive gain exaggerates spectral display by amplifying weak signals and noise.

Reducing gain restores the clarity of the spectral window and accurate envelope definition.

The goal is to optimize gain just enough to see the real flow signals without cluttering the display.

Differentiation from other options:

B. Adjust baseline: Useful in avoiding aliasing but does not affect gain-related noise.

C. Increase wall filter: Removes low-frequency signals from vessel wall motion but not background spectral noise.

D. Increase pulse repetition frequency (PRF): Used to reduce aliasing in high-velocity flow, not to address gain-related spectral clutter.

The tunica albuginea is the dense fibrous capsule that directly surrounds the testicular parenchyma. The tunica vaginalis is a serous covering surrounding the testis externally, and the dartos fascia and pampiniform plexus are part of the scrotal wall and spermatic cord, respectively.

According to Rumack’s Diagnostic Ultrasound:

“The tunica albuginea is the fibrous capsule surrounding the testis and forming septa within the gland.”

The ultrasound image demonstrates an irregular, complex fluid collection in the subareolar region of the breast with internal echoes, septations, and poorly defined margins. These sonographic findings are classic for a breast abscess, particularly in a patient presenting with clinical signs of infection—fever, redness, and localized tenderness.

A breast abscess is typically seen as:

A hypoechoic or anechoic area with thick walls

Presence of internal debris, septations, or floating echoes

Posterior acoustic enhancement

Increased peripheral vascularity on Doppler (surrounding inflammation)

Surrounding hyperechoic fat due to cellulitis

This clinical and imaging profile strongly supports the diagnosis of a breast abscess, most commonly seen in lactating women (puerperal mastitis) or in non-lactating women with chronic infection.

Comparison of answer choices:

A. Ductal ectasia usually presents with dilated ducts and minimal inflammatory changes, often asymptomatic or causing nipple discharge.

B. Abscess — Correct. The irregular fluid collection with complex echoes and clinical signs of infection supports this.

C. Sebaceous cysts are typically superficial, round, and well-defined with a punctum.

D. Galactocele appears as a well-circumscribed, fat-fluid level–containing lesion in lactating women but lacks surrounding inflammation.

The ultrasound image shows a transverse section through the upper abdomen. The arrow is pointing to a vascular structure running posterior to the pancreas and anterior to the left kidney. This vessel is the splenic vein.

Anatomically:

The splenic vein runs along the posterior border of the pancreas.

It courses medially to join the superior mesenteric vein (SMV) and form the portal vein.

It receives tributaries from the spleen, short gastric veins (draining the stomach), and the inferior mesenteric vein.

In this case, the question asks which organ is primarily drained via the vessel marked by the arrow. The splenic vein's main tributary is from the spleen.

Comparison of answer choices:

A. Spleen — Correct. The splenic vein is the primary drainage vessel for the spleen.

B. Stomach — Some gastric veins drain into the splenic vein, but the primary drainage is via left and right gastric veins into the portal system.

C. Left kidney — Drains into the left renal vein, not the splenic vein.

D. Duodenum — Drains mainly into the superior mesenteric vein (SMV).

An ultrasound of a fetus AI-generated content may be incorrect.

The ultrasound image shows a transverse (axial) view of the fetal abdomen. Notably, there is abnormal continuity of renal parenchyma across the midline anterior to the aorta, forming a U- or horseshoe-shaped structure. This is characteristic of a congenital anomaly known as a horseshoe kidney.

Horseshoe kidney is the most common fusion anomaly of the kidneys, occurring in approximately 1 in 400–600 live births. It results from fusion of the lower poles of both kidneys during fetal development. On prenatal ultrasound, this anomaly can be suspected when the kidneys appear closer to the midline than usual and are connected by an isthmus of renal tissue or fibrous band that crosses anterior to the spine and great vessels.

Typical sonographic findings include:

Abnormally located kidneys, often lower than expected

Renal fusion across the midline (usually at the lower poles)

Possible associated hydronephrosis or malrotation

Comparison to other anomalies:

This is not consistent with polycystic kidney disease (which would show diffusely echogenic kidneys with poor corticomedullary differentiation).

Duplex kidney would show duplicated collecting systems but not fusion across the midline.

Renal agenesis would demonstrate absence of renal tissue.

Posterior urethral valves would show a distended bladder with bilateral hydronephrosis, not midline fusion.

The spleen lies in the left hypochondrium, superior and lateral to the fundus of the stomach, and directly contacts the diaphragm. It occupies the space between the stomach and diaphragm. The liver and kidneys are located more medially or inferiorly.

According to Gray’s Anatomy for Students:

“The spleen lies posterolateral to the fundus of the stomach, separated from the diaphragm by its fibrous capsule.”

A wandering spleen occurs when the spleen is not adequately anchored by its supporting ligaments, allowing it to move freely within the abdomen. This increases the risk of splenic torsion, which compromises vascular supply and may result in infarction if not corrected.

According to Rumack’s Diagnostic Ultrasound:

“The most serious complication of a wandering spleen is torsion, which may result in splenic infarction.”

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.”

Postsurgical breast scarring may appear hypoechoic and irregular but typically shows no internal vascularity on Doppler imaging. In contrast, recurrent tumors generally exhibit increased internal vascular flow due to neovascularization. Therefore, absent Doppler signal helps suggest scar tissue rather than malignancy.

According to Stavros’ Breast Ultrasound:

“The absence of internal Doppler flow favors scar tissue, whereas recurrent malignancy typically demonstrates internal vascularity.”

The ultrasound image of the thyroid clearly shows posterior shadowing originating from the lateral edges of a rounded structure, which is indicative of edge shadow artifact. Edge shadowing occurs when an ultrasound beam passes tangentially to a rounded or curved structure, such as a cyst or blood vessel. The difference in sound wave refraction and beam divergence at the edges leads to decreased echo signals deep to the edges, creating linear hypoechoic bands — which is exactly what the arrows are pointing to in the image.

Edge shadow artifact is purely a result of beam physics and not a real anatomic or pathologic finding.

Key characteristics of edge shadowing:

Appears as a narrow, linear hypoechoic (dark) shadow extending deep to the edge of a curved interface (e.g., cyst, vessel, thyroid nodule)

Caused by refraction and beam deflection, leading to reduced beam intensity distal to the edges

Most commonly seen adjacent to cysts or fluid-filled structures

Differentiation from other options:

A. Focal enhancement: Appears as increased echogenicity distal to a fluid-filled structure due to lower attenuation of the sound beam through fluid (opposite of shadowing).

C. Speed error: A less common artifact that results in displacement of structures due to variation in assumed sound speed.

D. Comet tail: A reverberation artifact that appears as a series of closely spaced bright echoes, often associated with metallic objects or cholesterol crystals in adenomyomatosis.

An abdominal aortic aneurysm (AAA) measuring ≥5.5 cm represents a significantly increased risk of rupture and often requires surgical evaluation. The sonographer must report this critical finding immediately to the interpreting physician. The sonographer should never disclose a diagnosis directly to the patient.

According to AIUM and SRU Guidelines:

“An aortic diameter of 5.5 cm or greater should be promptly reported to the interpreting physician due to the high risk of rupture.”

Pancreas divisum occurs when the dorsal and ventral pancreatic ducts fail to fuse during embryologic development. This results in most pancreatic secretions draining through the minor papilla via the dorsal duct (duct of Santorini).

According to Rumack’s Diagnostic Ultrasound:

“In pancreas divisum, the dorsal and ventral pancreatic ducts fail to fuse, resulting in separate drainage systems.”

Testicular metastases are rare and usually identified in older patients. The most frequent primary site of malignancies metastasizing to the testes is theprostate. Studies (Ulbright and Young, 2008; Mosharafa et al., 2003) indicate that prostatic adenocarcinoma accounts for the highest number of testicular metastases, with lung and gastrointestinal tract malignancies also contributing less frequently. These metastases can be unilateral or bilateral and are often discovered incidentally during surgical intervention for prostate cancer.

The metastatic route involves retrograde venous extension, arterial embolism, or lymphatic dissemination. Histologically, prostatic adenocarcinoma in the testis can be confirmed viaimmunohistochemical markers like prostate-specific antigen (PSA), supporting its prostatic origin.

Before performing a paracentesis, assessment of the patient's coagulation status is crucial to minimize bleeding risk. The International Normalized Ratio (INR) is the standard lab value used to assess coagulation. Elevated INR may increase the risk of bleeding complications during the procedure. ALT, AFP, and bilirubin levels evaluate liver function or cancer progression but are not directly relevant to bleeding risk for this procedure.

As per AASLD and SIR guidelines:

“An INR and platelet count should be evaluated before paracentesis to assess bleeding risk. Minor elevations in INR (<1.5) may not contraindicate the procedure.” (AASLD Practice Guidance, 2021; SIR Consensus Guidelines, 2019).