Radiology - Aiims May 2011 - Just 7 Questions

Explanation
The distal duodenum showing a cap-like appearance is true regarding contrast radiography. This refers to the appearance of the duodenum when contrast material is used to visualize the gastrointestinal tract. The cap-like appearance is due to the shape of the duodenal bulb, which appears rounded and wider compared to the rest of the duodenum. This characteristic appearance helps in identifying the distal duodenum during contrast radiography.

Explanation
Samarium-135 is not a pure beta emitter because it undergoes both beta decay and gamma decay. Beta decay involves the emission of beta particles (electrons or positrons), while gamma decay involves the emission of gamma rays. In contrast, Yttrium-90, Phosphorus-32, and Strontium-89 are pure beta emitters as they only undergo beta decay without any accompanying gamma decay.

Explanation
Protein losing enteropathy is a condition characterized by the excessive loss of protein through the gastrointestinal tract. To diagnose this condition, various imaging tests can be used to assess the loss of proteins. Tc 99 Sotisumab is not a commonly used imaging test for diagnosing protein losing enteropathy. Therefore, it is not included in the list of options for diagnosing this condition.

Explanation
The central dot sign refers to the presence of a small central dot within a larger cystic lesion on imaging studies. This sign is typically seen in Caroli disease, a rare congenital disorder characterized by dilatation of the intrahepatic bile ducts. In this condition, the central dot represents a small portal vein branch that is surrounded by the dilated bile ducts. Polycystic liver disease, primary sclerosing cholangitis, and liver hamartoma do not typically exhibit the central dot sign.

Explanation
In left ventricular failure, there is an increase in pulmonary capillary wedge pressure, which can lead to fluid accumulation in the lungs. This fluid accumulation can be seen on imaging as Kerley B lines and increased vascularity in the upper lobes. However, oligaemic lung fields, which refer to decreased blood flow to the lungs, are not typically seen in left ventricular failure.

Explanation
PET (Positron Emission Tomography) is considered the gold standard investigation for recurrent gastrointestinal stromal tumors (GISTs). This imaging technique uses a radioactive tracer to detect metabolic activity in the body, allowing for the identification and localization of tumor cells. PET scans provide valuable information about the extent and location of recurrent GISTs, aiding in treatment planning and monitoring response to therapy. Other imaging modalities like MRI, MIBG, and USG may have their uses in certain situations, but PET is specifically preferred for recurrent GISTs due to its high sensitivity and ability to detect small lesions.

Explanation
The presence of diffuse wall thickening and a hyperechoic nodule with comet tail artifacts on a USG of the gall bladder is highly suggestive of adenomyomatosis. Adenomyomatosis is a benign condition characterized by hyperplasia of the mucosal and muscular layers of the gall bladder, resulting in the formation of intramural diverticula known as Rokitansky-Aschoff sinuses. These sinuses can appear as hyperechoic nodules with comet tail artifacts on imaging. Adenocarcinoma of the gall bladder typically presents as a focal mass rather than diffuse wall thickening, while xanthogranulomatous cholecystitis and porcelain gall bladder have distinct imaging features that are not described in the question.