Interventional Radiology

Interventional Radiology Indian Medical PG Question 1: Among the following arteries, which is dissected most frequently during angiography performed via the femoral route?

• A. Celiac trunk (Correct Answer)
• B. Inferior mesenteric artery
• C. Gastroduodenal artery
• D. Superior mesenteric artery

Interventional Radiology Explanation: ***Celiac trunk*** - The **celiac trunk** is the **most frequently dissected artery** during femoral route angiography due to its **challenging anatomical characteristics**. - It arises at a **steep downward angle** (typically 45-90°) from the anterior aorta, requiring significant **catheter manipulation and torque** to engage the orifice. - The acute angulation increases the risk of **subintimal catheter passage** during selective cannulation attempts, leading to iatrogenic dissection. - The need for **repeated attempts** and catheter repositioning when engaging the celiac trunk further elevates dissection risk. *Superior mesenteric artery* - While the **SMA** is frequently cannulated during abdominal angiography, it has a **more favorable anatomy** for catheter engagement. - Its **less acute angle** of origin (typically 30-45° caudally) and more anterior takeoff make it **easier to cannulate** with less manipulation. - Easier cannulation translates to **lower dissection risk** compared to the celiac trunk, despite being commonly studied. *Inferior mesenteric artery* - The **IMA** is a smaller vessel with lower flow, originating from the lower abdominal aorta. - It is **less frequently cannulated** in routine angiography due to its small caliber and distal location. - Lower frequency of selective cannulation means fewer opportunities for dissection. *Gastroduodenal artery* - The **GDA** is a **secondary branch** arising from the hepatic artery (itself a celiac trunk branch). - Due to its **distal location** and smaller size, selective GDA catheterization is uncommon in routine angiography. - Its infrequent selective cannulation makes dissection during femoral angiography extremely rare.

Interventional Radiology Indian Medical PG Question 2: Radiation exposure can lead to which type of thyroid carcinoma?

• A. Lymphoma
• B. Papillary carcinoma (Correct Answer)
• C. Medullary carcinoma
• D. Follicular carcinoma

Interventional Radiology Explanation: ***Papillary carcinoma*** - Papillary thyroid carcinoma is strongly associated with **radiation exposure**, particularly during childhood [1]. - It is the most prevalent type of thyroid cancer and typically has a **good prognosis** [1]. *Lymphoma* - Thyroid lymphoma is rare and generally not linked to **radiation exposure**; it often presents as a **rapidly enlarging goiter**. - It is more commonly associated with **autoimmune thyroiditis**, not primary radiation effects. *Follicular carcinoma* - Follicular carcinoma shows a correlation with **iodine deficiency** rather than radiation exposure [1]. - Its presentation is more subtle, compared to the classical association of **radiation with papillary carcinoma**. *Medullary carcinoma* - Medullary thyroid carcinoma is primarily linked to **familial syndromes** like MEN 2 and not radiation exposure. - It arises from **parafollicular C cells**, making it clinically distinct from radiation-related types. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1098-1099.

Interventional Radiology Indian Medical PG Question 3: Which one of the following imaging techniques gives the maximum radiation exposure to the patient?

• A. Chest X-ray
• B. MRI
• C. CT scan (Correct Answer)
• D. Bone scan

Interventional Radiology Explanation: ***CT scan*** - **CT scans** involve multiple X-ray projections and computer processing, resulting in a significantly higher radiation dose compared to conventional X-rays. - The effective dose from a single chest or abdominal CT scan can be equivalent to hundreds of standard chest X-rays, making it the highest radiation contributor among the options listed. *Chest X-ray* - A **chest X-ray** uses a very small amount of ionizing radiation, typically one of the lowest doses among diagnostic imaging techniques that involve radiation. - While it uses radiation, its contribution to overall exposure is minimal, especially compared to CT scans. *MRI* - **MRI (Magnetic Resonance Imaging)** uses strong magnetic fields and radio waves to create detailed images of organs and soft tissues, not ionizing radiation. - Therefore, it involves **no radiation exposure** to the patient. *Bone scan* - A **bone scan** uses a small amount of **radioactive tracer** (radionuclide) injected into the bloodstream, which is then detected by a special camera. - While it involves radiation, the dose is generally lower than that of a CT scan and is comparable to or slightly higher than a series of X-rays.

Interventional Radiology Indian Medical PG Question 4: What is the primary purpose of interventional studies in clinical research?

• A. Confirming Hypotheses
• B. Testing Hypotheses (Correct Answer)
• C. Manipulating Hypotheses
• D. Formulating Hypotheses

Interventional Radiology Explanation: ***Testing Hypotheses*** - Interventional studies, such as **randomized controlled trials**, are specifically designed to **test cause-and-effect relationships** by actively intervening. - They aim to determine if a specific intervention (e.g., a drug, a therapy) produces a hypothesized outcome. *Confirming Hypotheses* - While interventional studies can confirm hypotheses, their primary role is not just confirmation but the initial **rigorous testing** of a hypothesis under controlled conditions. - Confirmation often implies that previous evidence already strongly supports the hypothesis. *Manipulating Hypotheses* - Hypotheses themselves are not "manipulated"; rather, the **variables** within the study design (e.g., treatment groups, dosages) are manipulated to test the hypothesis. - This option incorrectly applies the concept of manipulation to the hypothesis. *Formulating Hypotheses* - Hypothesis formulation usually occurs during the **observational research phase** or through literature review, *before* interventional studies are designed. - Observational studies or descriptive research are more typically used for generating new hypotheses.

Interventional Radiology Indian Medical PG Question 5: Transjugular intrahepatic portosystemic shunt (TIPS) is contraindicated in which of the following conditions?

• A. Post-shunt encephalopathy
• B. Cirrhosis
• C. Portal vein thrombosis (Correct Answer)
• D. Variceal bleeding

Interventional Radiology Explanation: **Explanation:** **Transjugular Intrahepatic Portosystemic Shunt (TIPS)** is an interventional procedure where a shunt is created between the hepatic vein and the portal vein to reduce portal hypertension. **Why Portal Vein Thrombosis (PVT) is the correct answer:** The success of a TIPS procedure depends on the ability to access and pass a wire through the portal vein to establish the shunt. In cases of **extensive or cavernous portal vein thrombosis**, the target vessel is either occluded or replaced by small collateral vessels, making the procedure technically impossible or highly hazardous. While partial PVT is sometimes managed by experienced interventionists, complete PVT remains a classic **absolute contraindication** in standard practice. **Analysis of Incorrect Options:** * **Post-shunt encephalopathy (A):** This is a common **complication** of TIPS, not a contraindication for the initial procedure. However, pre-existing severe hepatic encephalopathy is a relative contraindication. * **Cirrhosis (B):** Cirrhosis with portal hypertension is the **primary indication** for TIPS (specifically for refractory ascites or variceal bleeding). * **Variceal bleeding (D):** This is a **major indication** for TIPS, especially when bleeding is refractory to endoscopic management (Rescue TIPS). **High-Yield Clinical Pearls for NEET-PG:** * **Absolute Contraindications:** Severe congestive heart failure (R-sided), severe pulmonary hypertension, and multiple hepatic cysts/polycystic liver disease. * **Relative Contraindications:** Active systemic infection, severe coagulopathy, and rapidly progressing hepatoma. * **MELD Score:** A MELD score >18 is associated with higher mortality post-TIPS. * **Mechanism:** TIPS bypasses the liver parenchyma, effectively converting sinusoidal portal hypertension into a side-to-side portocaval shunt.

Interventional Radiology Flashcard 1 of 5

Question: What is the investigation of choice for a cirisoid aneurysm?_____

Answer: Angiography

Interventional Radiology Flashcard 2 of 5

Question: The Father of interventional radiology is _____

Answer: Charles Dotter

Interventional Radiology Flashcard 3 of 5

Question: Tumor blush is characteristic of _____

Answer: Angiofibroma (AVM)

Interventional Radiology Flashcard 4 of 5

Question: The image shows a _____ catheter, which is routinely used for percutaneous drainage.

Answer: pigtail

Interventional Radiology Flashcard 5 of 5

Question: Portosystemic shunts may be treated with _____ between the portal and hepatic veins

Answer: TIPS