Free and Premium ARDMS AB-Abdomen Dumps Questions Answers

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.”

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.”

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.

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).

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 image shows a color Doppler ultrasound of the main portal vein (MPV), which appears irregular and replaced by multiple small, serpiginous vascular channels — a hallmark of cavernous transformation. Cavernous transformation of the portal vein is a late complication of chronic portal vein thrombosis, in which collateral vessels develop around the thrombosed portal vein to bypass the obstruction.

Key Doppler ultrasound features of cavernous transformation:

Absence of a normal portal vein

Multiple tortuous vessels in the porta hepatis

Color Doppler shows hepatopetal flow in these channels

Low velocity, continuous waveform flow in collateral vessels

Differentiation from other options:

B. Portal vein thrombosis: Would show an absence of color flow within the portal vein lumen and possibly echogenic material within the vessel. There would be no serpiginous collateral vessels yet if it's an acute process.

C. Portal hypertension: Often diagnosed with other sonographic findings (e.g., splenomegaly, reversed portal flow, varices) but not characterized by the replacement of the portal vein by collateral vessels.

D. Tumor extension: Typically appears as echogenic intraluminal material within the portal vein with arterial waveforms on Doppler due to neovascularity. Tumor thrombus can be seen in hepatocellular carcinoma or pancreatic cancer, not multiple small collateral vessels.

The ultrasound image shows the liver in a transverse view with the arrow pointing to the middle hepatic vein (MHV). The MHV is a key sonographic landmark that anatomically divides the right and left lobes of the liver.

According to Couinaud's segmental anatomy, which is the basis for surgical and radiological liver segmentation:

The middle hepatic vein runs within the main lobar fissure.

It separates the right lobe (segments V–VIII) from the left lobe (segments II–IV).

This division is crucial in liver surgery and interventional procedures.

Comparison of answer choices:

A. Right anterior and posterior segments are divided by the right hepatic vein, not the middle hepatic vein.

B. Right and left lobes — Correct. The middle hepatic vein, shown by the arrow, defines this boundary.

C. Left medial and lateral segments are divided by the left hepatic vein or falciform ligament.

D. Left superior and inferior is not a standard anatomic division in liver segmentation.

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 technique shown in the video is compression. In ultrasound imaging—especially of soft tissue masses, the bowel, or venous structures—compression is used to evaluate the compressibility of structures. The image demonstrates a classic grayscale ultrasound view of a lesion or structure being compressed with the probe.

Compression sonography is particularly important in:

Evaluating venous patency (e.g., for deep vein thrombosis)

Differentiating cystic from solid structures

Evaluating bowel wall abnormalities or intussusception

Assessing lymph nodes and soft tissue masses (as shown here)

When a structure compresses easily under probe pressure, it suggests that the lesion is fluid-filled or soft. In contrast, incompressibility may indicate a solid mass or thrombus.

Differentiation from other options:

B. Valsalva: Involves forced expiration against a closed airway, used primarily to assess venous reflux or inguinal hernias—not what is demonstrated here.

C. Exhalation: A respiratory maneuver that passively alters thoracoabdominal pressure, not actively performed by the operator or causing focal structural change.

D. Deep inspiration: Used to improve visualization of the liver, diaphragm, or gallbladder—not to evaluate the compressibility of soft tissue.

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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Salivary glands are superficial structures, and high-frequency transducers (10–15 MHz) are optimal to obtain high spatial resolution. Lower frequencies are inappropriate as they lack sufficient resolution for superficial structures. A 12 MHz transducer provides excellent detail necessary for detecting small lesions, duct abnormalities, and vascular structures.

According to Rumack et al., Diagnostic Ultrasound:

"High-frequency linear transducers (10–15 MHz) are recommended for evaluating superficial structures such as salivary glands." (Rumack CM et al., Diagnostic Ultrasound, 5th ed.).

Intrahepatic biliary dilatation with a normal common bile duct (CBD) is typically caused by obstruction located at or above the level of the hepatic duct confluence. A tumor at the porta hepatis, such as cholangiocarcinoma (Klatskin tumor), is a classic cause of this pattern. The porta hepatis is the site where the right and left hepatic ducts join to form the common hepatic duct. A mass at this location can obstruct the intrahepatic ducts while leaving the distal CBD unaffected and of normal caliber.

By contrast:

Portal vein thrombus (A) affects vascular flow but does not directly obstruct bile ducts.

Choledocholithiasis (C) obstructs the CBD, typically resulting in both intrahepatic and extrahepatic duct dilatation.

Acute pancreatitis (D) may cause distal CBD compression if there is associated inflammation or pseudocyst formation, but typically results in extrahepatic duct dilatation rather than isolated intrahepatic dilation.

Reference Extracts:

Rumack CM, Wilson SR, Charboneau JW, Levine D. Diagnostic Ultrasound, 5th ed. Elsevier, 2017. Chapter: Biliary Tract: “Klatskin tumors cause proximal (intrahepatic) biliary dilatation while the distal bile duct remains normal in caliber.”

Gore RM, Levine MS. Textbook of Gastrointestinal Radiology, 4th ed. Saunders, 2015.

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Von Hippel-Lindau (VHL) syndrome is a genetic disorder associated with multiple pancreatic cysts, pancreatic neuroendocrine tumors, and other systemic neoplasms. While cystic fibrosis can produce thickened pancreatic secretions, it rarely causes true pancreatic cysts.

According to Rumack’s Diagnostic Ultrasound:

“Multiple pancreatic cysts are strongly associated with Von Hippel Lindau syndrome.”

The image shows a small hepatic lesion located very close to the anterior liver capsule, as indicated by the arrow. When imaging very superficial or near-field structures like subcapsular hepatic lesions, using a standoff pad is the most effective technique for optimizing visualization.

A standoff pad (also known as an acoustic stand-off or gel pad) helps increase the distance between the transducer and the superficial target. This improves the focus and beam shape for near-field imaging and minimizes reverberation and ring-down artifacts. It allows better evaluation of superficial lesions by positioning them within the focal zone of the transducer, which is usually set a few millimeters below the probe surface.

Differentiation from other options:

A. Decrease depth: While reducing depth can help center deeper lesions in the field of view, it does not address issues with near-field resolution.

B. Scan in upright position: This may help in gallbladder or fluid positioning but is not optimal for improving visualization of superficial liver lesions.

C. Move the transducer focus: Adjusting focus deeper into the image won't enhance resolution of very superficial structures unless a standoff is used to bring the lesion into the focal zone.

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.”

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.”

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.

Acute tubular necrosis (ATN) is the most common cause of early graft dysfunction following renal transplantation. It results from ischemia-reperfusion injury during the transplantation process. Ultrasound findings may be nonspecific but Doppler may show elevated resistive indices.

Ureterocele (A) is a congenital anomaly.

Transplant artery stenosis (C) is a late complication.

Transitional cell carcinoma (D) is rare and not typically an early complication.

Reference Extracts:

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

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

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Caput medusae refers to dilated paraumbilical veins due to portal hypertension. When portal venous pressure rises, collateral channels may open along the ligamentum teres and recanalized paraumbilical vein, resulting in visible dilated veins radiating from the umbilicus.

Esophageal varices (B) are gastroesophageal collaterals.

Coronary vein varices (C) involve gastric veins.

Splenic vein varices (D) are typically localized to the splenic hilum.

Reference Extracts:

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

Gore RM, Levine MS. Textbook of Gastrointestinal Radiology. 4th ed. Saunders, 2015.

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The most common symptom of cholelithiasis (gallstones) is biliary colic, characterized by intermittent right upper quadrant or epigastric pain often triggered by fatty meals. Jaundice occurs in complications such as choledocholithiasis.

According to Rumack’s Diagnostic Ultrasound:

“Gallstones may cause biliary colic — episodic upper abdominal pain often related to food intake.”

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.”

Branchial cleft cysts are congenital epithelial cysts that typically occur laterally in the neck, often anterior to the sternocleidomastoid muscle, and lateral to the thyroid gland. The second branchial cleft cyst is the most common type and is found in the lateral neck region.

Medial (B) would be more consistent with thyroglossal duct cysts.

Anterior (C) or posterior (D) do not specifically describe branchial cyst location relative to the thyroid.

Reference Extracts:

Som PM, Curtin HD. Head and Neck Imaging. 5th ed. Elsevier, 2011.

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

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Ring-down artifact occurs when gas bubbles resonate or oscillate, creating continuous echoes distal to the structure that appear as a vertical, echogenic band extending posteriorly. This is distinct from reverberation, which produces multiple discrete reflections.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Ring-down artifact results from resonance of gas bubbles, producing a continuous, echogenic tail distal to the reflecting interface.”

In hepatic steatosis (fatty liver), increased echogenicity can obscure visualization of deeper structures like the common bile duct. Lowering the transducer frequency increases sound wave penetration, allowing better visualization of deep structures despite increased liver echogenicity. Decreasing gain or increasing dynamic range primarily adjusts image brightness and contrast but does not improve penetration.

According to Rumack’s Diagnostic Ultrasound:

“Lower frequency transducers are used to improve penetration and visualization of deeper structures in patients with fatty liver.”

Adrenal adenomas are the most common adrenal tumors in adults. They are often discovered incidentally (adrenal incidentalomas) and are usually nonfunctioning, though some may secrete cortisol or aldosterone. Neuroblastoma is common in children, pheochromocytomas are rarer catecholamine-producing tumors, and adrenal cortical carcinoma is malignant but much less common than adenomas.

According to Rumack’s Diagnostic Ultrasound:

“Adrenal adenomas are the most common adrenal masses in adults, frequently identified incidentally on imaging studies.”

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.”

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.

Downstream from a significant renal artery stenosis, the acceleration time is prolonged due to delayed systolic upstroke (“tardus-parvus waveform”). This is a sensitive Doppler parameter for detecting hemodynamically significant stenosis. Spectral broadening usually occurs at the stenotic site, not distal to it.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Prolonged acceleration time and reduced acceleration index characterize tardus-parvus waveforms distal to renal artery stenosis.”

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.

The image shows a transverse view of the left lobe of the liver with the portal triads clearly visible. The "parallel channel" or "double barrel" sign is observed—where dilated intrahepatic bile ducts run alongside the portal veins, creating a characteristic sonographic pattern of paired anechoic (black) tubular structures.

This sonographic feature is diagnostic for dilated intrahepatic bile ducts and is typically seen in obstructive jaundice or biliary obstruction from conditions such as:

Choledocholithiasis (stone in the common bile duct)

Stricture or mass compressing the bile ducts

Cholangiocarcinoma

The intrahepatic bile ducts normally are too small to visualize clearly unless dilated. Their dilation gives the liver a "too many tubes" appearance, where bile ducts become as prominent as the portal veins.

Comparison of answer choices:

A. Normal intrahepatic ducts are not usually seen this clearly or prominently on ultrasound.

B. Dilated intrahepatic — Correct. The parallel channel sign supports this diagnosis.

C. Dilated common bile duct would be visualized extrahepatically, typically anterior to the portal vein near the head of the pancreas.

D. Dilated common hepatic duct is also extrahepatic and seen in the porta hepatis, not within the liver parenchyma.

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.

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.)

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.”

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.”

Color Doppler imaging can detect ureteral jets, which represent urine entering the bladder from the ureters. The presence of bilateral ureteral jets confirms ureteral patency. Gray scale may show hydronephrosis but does not directly assess flow.

According to Rumack’s Diagnostic Ultrasound:

“Color Doppler demonstrates ureteral jets within the bladder, confirming ureteral patency.”

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.”

Annular pancreas is a congenital anomaly in which pancreatic tissue encircles the second part of the duodenum, potentially causing partial or complete duodenal obstruction (atresia). It is due to abnormal migration of the ventral pancreatic bud.

According to Rumack’s Diagnostic Ultrasound:

“Annular pancreas results from failure of the ventral pancreatic bud to rotate properly, leading to encirclement of the duodenum.”

Urinomas are collections of urine in the retroperitoneum that result from trauma, surgery, or obstruction causing urine leakage. Trauma is a frequent cause of urinoma formation due to disruption of the urinary tract.

According to Rumack’s Diagnostic Ultrasound:

“Urinomas may develop as a complication of trauma, surgery, or obstructive uropathy with urinary extravasation into the retroperitoneum.”

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.”

Wooden foreign bodies are often difficult to detect on CT because of their low radiodensity, but they are highly echogenic with posterior shadowing or reverberation on ultrasound, making ultrasound superior for detecting retained wooden objects. Glass, metal, and stones are better visualized with CT due to their high radiodensity.

According to AIUM and musculoskeletal ultrasound literature:

“Wood is poorly visualized on CT but demonstrates high reflectivity and acoustic shadowing on ultrasound.”

Patients with liver disease often have coagulopathy due to impaired synthesis of clotting factors. This places them at greater risk for bleeding or hematoma formation after biopsy. While hypertension may increase bleeding risk slightly, liver disease presents a significantly higher risk due to impaired coagulation.

According to the Society of Interventional Radiology (SIR) guidelines:

“Liver dysfunction is a significant risk factor for post-biopsy hemorrhage due to associated coagulopathy.”

The structure indicated by the arrow is the middle hepatic vein. This is confirmed by both its anatomical location within the liver and its Doppler waveform characteristics.

Key ultrasound and Doppler features:

The middle hepatic vein runs between the right and left hepatic lobes and drains into the inferior vena cava (IVC). On grayscale imaging, it appears as a tubular anechoic structure extending toward the IVC.

On spectral Doppler, hepatic veins (including the middle hepatic vein) demonstrate a characteristic triphasic waveform due to pressure changes in the right atrium. This triphasic pattern is clearly visible in the Doppler tracing below the image.

This differs significantly from the monophasic low-resistance flow of the hepatic artery or the continuous hepatopetal flow of the portal vein.

Differentiation from other options:

A. Left portal vein: Would show continuous, hepatopetal flow (toward the liver) and lies more anterior and medial within the liver.

C. Proper hepatic artery: Small-caliber vessel with low-resistance pulsatile waveform (not triphasic).

D. Inferior vena cava: Lies posterior to the liver and demonstrates phasic flow with respiration, but this vessel is more centrally located and not shown in this field of view.

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.

Transudative pleural effusions result from imbalances in hydrostatic and oncotic pressures, most commonly caused by congestive heart failure (CHF). In CHF, elevated hydrostatic pressure in the pulmonary capillaries leads to fluid leakage into the pleural space without significant protein or cellular content (hence, transudate). Exudative effusions (associated with infections, malignancy, and inflammation) are more often seen with pulmonary emboli, lymphoma, or empyema.

According to Light’s criteria (which differentiates transudates from exudates):

"Congestive heart failure remains the leading cause of transudative pleural effusions." (Light RW. Pleural Diseases, 6th ed.).

The ultrasound image demonstrates a dilated common bile duct (CBD), measuring approximately 7.7 mm in diameter. A normal CBD should generally measure less than 6 mm in a patient under 60 years old and may increase approximately 1 mm per decade thereafter or after cholecystectomy.

In the absence of gallstones within the CBD, one of the most concerning causes of CBD dilation is distal obstruction due to an extrinsic compressive lesion. The most common and clinically significant cause of distal CBD obstruction is a mass at the head of the pancreas.

A pancreatic head mass (e.g., adenocarcinoma) may compress the distal CBD and pancreatic duct simultaneously, resulting in the “double duct sign” — dilation of both the CBD and pancreatic duct. This is a classic finding in pancreatic cancer.

Comparison of answer choices:

A. Liver mass — unlikely to cause isolated CBD dilation unless invading the porta hepatis.

B. Cystic duct stone — may cause gallbladder hydrops but typically not CBD dilation unless Mirizzi syndrome is present.

C. Pancreatic head mass — Correct. This is the most likely cause of painless progressive CBD dilation without visible intraductal stones.

D. Gallbladder stones — These may be associated with biliary colic or cholecystitis but typically do not cause CBD dilation unless the stone has migrated and obstructed the distal duct.