ARDMS AB-Abdomen - Abdomen Sonography Examination

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.”

The image demonstrates a gallbladder with a possible echogenic focus (likely a gallstone) and posterior acoustic shadowing. This is suggestive of cholelithiasis. To differentiate uncomplicated gallstones from acute cholecystitis, the most effective technique is to assess for a positive sonographic Murphy sign.

A positive sonographic Murphy sign refers to the presence of focal tenderness over the gallbladder when it is directly palpated with the ultrasound transducer. It is a strong indicator of acute cholecystitis when combined with other features such as gallbladder wall thickening, pericholecystic fluid, and gallstones.

Sonographic Murphy sign — key points:

Assessed during real-time scanning

Localized tenderness when pressure is applied over the gallbladder

Highly sensitive for acute cholecystitis (especially in the presence of stones)

Differentiation from other options:

A. Use compound imaging: Improves image quality by reducing artifacts but does not verify tenderness or confirm acute inflammation.

B. Change the patient’s position: Helpful to confirm mobility of gallstones, but not diagnostic of inflammation.

C. Ask patient to perform Valsalva: Used primarily in vascular studies (e.g., assessing for varicocele or venous reflux), not relevant here.

After successful TIPS placement, the intrahepatic portal venous branches continue to exhibit hepatopetal (toward the liver) flow, while the stent itself shows continuous, relatively high-velocity monophasic flow. Hepatofugal flow in intrahepatic branches may indicate shunt dysfunction.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Normal post-TIPS Doppler shows hepatopetal flow in the intrahepatic portal veins and continuous high-velocity flow within the stent.”

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.

Pancreatic ductal adenocarcinoma is by far the most common pancreatic malignancy, accounting for approximately 85–90% of pancreatic cancers. It typically arises from the exocrine portion of the pancreas, most frequently in the pancreatic head. Islet cell (neuroendocrine) tumors and cystic neoplasms (e.g., mucinous cystadenocarcinoma) are far less common.

According to Rumack’s Diagnostic Ultrasound:

“Adenocarcinoma is the most common malignant neoplasm of the pancreas, representing the vast majority of pancreatic cancers.”

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 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.

Portal veins course horizontally within the liver and have echogenic walls due to their fibrous sheath. In contrast, hepatic veins course vertically toward the IVC and lack echogenic walls. Hepatic veins also demonstrate a triphasic waveform.

According to Rumack’s Diagnostic Ultrasound:

“Portal veins course horizontally within the liver and are easily recognized by their echogenic walls.”

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 renal arteries originate from the abdominal aorta just inferior to the superior mesenteric artery (SMA). The SMA arises anteriorly from the abdominal aorta at the level of L1, and just below it, the renal arteries branch laterally. The splenic vein, portal vein, and hepatic artery are located more superiorly in relation to the renal arteries.

According to Moore's Clinically Oriented Anatomy:

"The superior mesenteric artery arises from the anterior surface of the abdominal aorta just above the renal arteries." (Moore KL et al., Clinically Oriented Anatomy, 8th ed.)