UPSC-CMS 2023 — Radiology

Q: The sonographic finding of a cyst containing clear fluid is described as

Anechoic. ***Anechoic*** - **Anechoic** refers to structures that do not produce echoes, appearing **black** on ultrasound. - A simple cyst with clear fluid allows sound waves to pass through without reflection, making it appear anechoic. *Isoechoic* - **Isoechoic** describes structures that have the same echogenicity as surrounding tissues. - This term is typically used for solid tissues rather than fluid-filled cysts. *Hypoechoic* - **Hypoechoic** structures produce fewer echoes than surrounding tissues, appearing darker but not completely black. - This is often seen in solid lesions or complex cysts with internal debris, not clear fluid. *Hyperechoic* - **Hyperechoic** structures produce many echoes, appearing brighter than surrounding tissues. - This can be indicative of calcifications, fat, or certain solid masses, not clear fluid. [Practice more Radiology PYQs on OnCourse]

Q: Among the following, which is the investigation of choice for evaluation of common bile duct (CBD)?

MRCP. ***Correct: MRCP*** - **Magnetic Resonance Cholangiopancreatography (MRCP)** is the investigation of choice for comprehensive CBD evaluation - **Non-invasive technique** with high sensitivity (95%) and specificity (97%) for biliary pathology - **Provides detailed anatomical visualization** of the entire biliary tree without radiation or contrast agents - **Superior for detecting** CBD stones, strictures, and obstructions *Incorrect: CECT Abdomen* - Can visualize the CBD but provides less detailed luminal information compared to MRCP - More useful for assessing surrounding structures, tumor staging, and vascular involvement - Not the primary investigation of choice for biliary tree evaluation *Incorrect: HIDA scan* - Hepatobiliary Iminodiacetic Acid scan is a functional study that assesses gallbladder function and cystic duct patency - Tracks radioactive tracer flow but does not provide detailed anatomical imaging - Cannot visualize the cause of obstruction, making it unsuitable for primary CBD evaluation *Incorrect: Ultrasonography* - Initial screening modality that is readily available and non-invasive - Can detect CBD dilation and some stones but has limited sensitivity - Limited by bowel gas interference and operator dependency - Provides less detail than MRCP, especially for distal CBD segments [Practice more Radiology PYQs on OnCourse]

Q: A "double bubble" sign on an antenatal ultrasound examination in a gravid woman is diagnostic of

Duodenal atresia. ***Duodenal atresia*** - The **"double bubble" sign** on antenatal ultrasound is highly characteristic of duodenal atresia, representing a dilated **stomach** and a dilated **proximal duodenum**. - This finding indicates an **obstruction distal to the pylorus**, preventing normal passage of fluid and gas. *Anencephaly* - Anencephaly is a severe birth defect where a baby is born without parts of the **brain** and **skull**, and it is characterized by the absence of the skull vault. - It is identified by the absence of the **cranial vault** and **cerebral hemispheres**, not by an abdominal "double bubble." *Meningomyelocele* - Meningomyelocele is a type of **spina bifida** where the spinal cord and meninges protrude through an opening in the back. - This condition is typically diagnosed by visualizing a **spinal defect** with a sac-like protrusion, not gastric or duodenal distension. *Hydronephrosis* - Hydronephrosis involves the **swelling of one or both kidneys** due to a buildup of urine, often caused by an obstruction in the urinary tract. - It is identified by **dilated renal pelves** and calyces on ultrasound, not the "double bubble" sign, which relates to the gastrointestinal tract. [Practice more Radiology PYQs on OnCourse]

Q: Foetal anaemia can be detected non-invasively by Doppler ultrasonography on the basis of an increase in the

Peak systolic velocity of the middle cerebral artery. ***Peak systolic velocity of the middle cerebral artery*** - **Foetal anaemia** causes increased **cardiac output** and redistribution of blood flow to vital organs, leading to an increase in **peak systolic velocity (PSV)** in the **middle cerebral artery (MCA)**. - This increased velocity indicates **cerebral vasodilation**, a compensatory mechanism to maintain oxygen delivery to the foetal brain in situations of hypoxia due to anaemia. *SD ratio in the anterior cerebral artery* - The **SD ratio (systolic/diastolic ratio)** is more commonly used in umbilical artery flow. A higher SD ratio in cerebral arteries typically suggests increased downstream resistance, which is not characteristic of foetal anaemia. - In foetal anaemia, the cerebral arteries would typically show **decreased resistance**, leading to a lower, not higher, SD ratio. *SD ratio in the umbilical artery* - An increased **SD ratio in the umbilical artery** often indicates **placental insufficiency** or **foetal growth restriction**, not necessarily **foetal anaemia**. - While placental insufficiency can lead to foetal anaemia, the direct Doppler marker for anaemia is the MCA PSV, reflecting the foetal response to hypoxia. *Peak systolic velocity of the anterior cerebral artery* - While both anterior and middle cerebral arteries are part of the cerebral circulation, the **middle cerebral artery (MCA)** is the most widely validated and sensitive vessel for detecting changes in **foetal blood flow** due to **anaemia**. - Changes in the anterior cerebral artery's PSV are not as reliably linked to the diagnosis of foetal anaemia as those in the MCA. [Practice more Radiology PYQs on OnCourse]

Q: "Mickey Mouse Sign" during B-mode duplex ultrasound imaging comprises :

Popliteal artery, Popliteal vein and Tibial nerve. ***Popliteal artery, Popliteal vein and Tibial nerve*** - The \"Mickey Mouse Sign\" in the **popliteal fossa** visualizes the **popliteal artery** as the \"head\" and the **popliteal vein** and **tibial nerve** as the \"ears.\" - This specific configuration is seen on **transverse B-mode ultrasound** of the popliteal fossa and is crucial for identifying neurovascular structures for **popliteal nerve blocks** and vascular assessments. - The tibial nerve is the largest branch of the sciatic nerve in the popliteal fossa and runs alongside these vessels. *Common femoral vein, Common femoral artery and Great Saphenous vein* - This is the **most commonly referenced \"Mickey Mouse Sign\"** in ultrasound, visualized in the **groin/femoral region**. - The **common femoral artery** forms the \"head\" and the **common femoral vein** and **great saphenous vein** (at its junction) form the \"ears.\" - This sign is important for **central venous access**, **femoral vessel assessment**, and **avoiding complications** during procedures. *Anterior tibial artery, Dorsalis pedis artery and Extensor hallucis tendon* - These structures are located in the **lower leg and foot**, not in a configuration that forms the Mickey Mouse sign. - They are important for assessing **peripheral vascular status** but do not constitute this specific ultrasound landmark. *Brachial artery, Basilic vein and Biceps tendon* - These are structures found in the **upper arm**. - While important for upper extremity vascular imaging, they do not form the \"Mickey Mouse Sign\" pattern on ultrasound. [Practice more Radiology PYQs on OnCourse]

6 Previous Year Questions with Answers & Explanations

Questions

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The sonographic finding of a cyst containing clear fluid is described as

Among the following, which is the investigation of choice for evaluation of common bile duct (CBD)?

A "double bubble" sign on an antenatal ultrasound examination in a gravid woman is diagnostic of

Foetal anaemia can be detected non-invasively by Doppler ultrasonography on the basis of an increase in the

"Mickey Mouse Sign" during B-mode duplex ultrasound imaging comprises :

Which one of the following statements is correct regarding eFAST in trauma? 1. It is a technique to assess free fluid in abdominal cavity, thoracic cavity, and pericardium. 2. It is a technique to assess free fluid in pelvic cavity. 3. It is a technique to assess free fluid in pleural cavity. Select the correct answer using the code given below:

UPSC-CMS 2023 - Radiology UPSC-CMS Practice Questions and MCQs

Question 1: The sonographic finding of a cyst containing clear fluid is described as

A. Isoechoic
B. Hypoechoic
C. Hyperechoic
D. Anechoic (Correct Answer)

Explanation: ***Anechoic*** - **Anechoic** refers to structures that do not produce echoes, appearing **black** on ultrasound. - A simple cyst with clear fluid allows sound waves to pass through without reflection, making it appear anechoic. *Isoechoic* - **Isoechoic** describes structures that have the same echogenicity as surrounding tissues. - This term is typically used for solid tissues rather than fluid-filled cysts. *Hypoechoic* - **Hypoechoic** structures produce fewer echoes than surrounding tissues, appearing darker but not completely black. - This is often seen in solid lesions or complex cysts with internal debris, not clear fluid. *Hyperechoic* - **Hyperechoic** structures produce many echoes, appearing brighter than surrounding tissues. - This can be indicative of calcifications, fat, or certain solid masses, not clear fluid.

Question 2: Among the following, which is the investigation of choice for evaluation of common bile duct (CBD)?

A. CECT Abdomen
B. MRCP (Correct Answer)
C. HIDA scan
D. Ultrasonography

Explanation: ***Correct: MRCP*** - **Magnetic Resonance Cholangiopancreatography (MRCP)** is the investigation of choice for comprehensive CBD evaluation - **Non-invasive technique** with high sensitivity (95%) and specificity (97%) for biliary pathology - **Provides detailed anatomical visualization** of the entire biliary tree without radiation or contrast agents - **Superior for detecting** CBD stones, strictures, and obstructions *Incorrect: CECT Abdomen* - Can visualize the CBD but provides less detailed luminal information compared to MRCP - More useful for assessing surrounding structures, tumor staging, and vascular involvement - Not the primary investigation of choice for biliary tree evaluation *Incorrect: HIDA scan* - Hepatobiliary Iminodiacetic Acid scan is a functional study that assesses gallbladder function and cystic duct patency - Tracks radioactive tracer flow but does not provide detailed anatomical imaging - Cannot visualize the cause of obstruction, making it unsuitable for primary CBD evaluation *Incorrect: Ultrasonography* - Initial screening modality that is readily available and non-invasive - Can detect CBD dilation and some stones but has limited sensitivity - Limited by bowel gas interference and operator dependency - Provides less detail than MRCP, especially for distal CBD segments

Question 3: A "double bubble" sign on an antenatal ultrasound examination in a gravid woman is diagnostic of

A. Duodenal atresia (Correct Answer)
B. Anencephaly
C. Meningomyelocele
D. Hydronephrosis

Explanation: ***Duodenal atresia*** - The **"double bubble" sign** on antenatal ultrasound is highly characteristic of duodenal atresia, representing a dilated **stomach** and a dilated **proximal duodenum**. - This finding indicates an **obstruction distal to the pylorus**, preventing normal passage of fluid and gas. *Anencephaly* - Anencephaly is a severe birth defect where a baby is born without parts of the **brain** and **skull**, and it is characterized by the absence of the skull vault. - It is identified by the absence of the **cranial vault** and **cerebral hemispheres**, not by an abdominal "double bubble." *Meningomyelocele* - Meningomyelocele is a type of **spina bifida** where the spinal cord and meninges protrude through an opening in the back. - This condition is typically diagnosed by visualizing a **spinal defect** with a sac-like protrusion, not gastric or duodenal distension. *Hydronephrosis* - Hydronephrosis involves the **swelling of one or both kidneys** due to a buildup of urine, often caused by an obstruction in the urinary tract. - It is identified by **dilated renal pelves** and calyces on ultrasound, not the "double bubble" sign, which relates to the gastrointestinal tract.

Question 4: Foetal anaemia can be detected non-invasively by Doppler ultrasonography on the basis of an increase in the

A. SD ratio in the anterior cerebral artery
B. Peak systolic velocity of the anterior cerebral artery
C. Peak systolic velocity of the middle cerebral artery (Correct Answer)
D. SD ratio in the umbilical artery

Explanation: ***Peak systolic velocity of the middle cerebral artery*** - **Foetal anaemia** causes increased **cardiac output** and redistribution of blood flow to vital organs, leading to an increase in **peak systolic velocity (PSV)** in the **middle cerebral artery (MCA)**. - This increased velocity indicates **cerebral vasodilation**, a compensatory mechanism to maintain oxygen delivery to the foetal brain in situations of hypoxia due to anaemia. *SD ratio in the anterior cerebral artery* - The **SD ratio (systolic/diastolic ratio)** is more commonly used in umbilical artery flow. A higher SD ratio in cerebral arteries typically suggests increased downstream resistance, which is not characteristic of foetal anaemia. - In foetal anaemia, the cerebral arteries would typically show **decreased resistance**, leading to a lower, not higher, SD ratio. *SD ratio in the umbilical artery* - An increased **SD ratio in the umbilical artery** often indicates **placental insufficiency** or **foetal growth restriction**, not necessarily **foetal anaemia**. - While placental insufficiency can lead to foetal anaemia, the direct Doppler marker for anaemia is the MCA PSV, reflecting the foetal response to hypoxia. *Peak systolic velocity of the anterior cerebral artery* - While both anterior and middle cerebral arteries are part of the cerebral circulation, the **middle cerebral artery (MCA)** is the most widely validated and sensitive vessel for detecting changes in **foetal blood flow** due to **anaemia**. - Changes in the anterior cerebral artery's PSV are not as reliably linked to the diagnosis of foetal anaemia as those in the MCA.

Question 5: "Mickey Mouse Sign" during B-mode duplex ultrasound imaging comprises :

A. Popliteal artery, Popliteal vein and Tibial nerve (Correct Answer)
B. Common femoral vein, Common femoral artery and Great Saphenous vein
C. Anterior tibial artery, Dorsalis pedis artery and Extensor hallucis tendon
D. Brachial artery, Basilic vein and Biceps tendon

Explanation: ***Popliteal artery, Popliteal vein and Tibial nerve*** - The \"Mickey Mouse Sign\" in the **popliteal fossa** visualizes the **popliteal artery** as the \"head\" and the **popliteal vein** and **tibial nerve** as the \"ears.\" - This specific configuration is seen on **transverse B-mode ultrasound** of the popliteal fossa and is crucial for identifying neurovascular structures for **popliteal nerve blocks** and vascular assessments. - The tibial nerve is the largest branch of the sciatic nerve in the popliteal fossa and runs alongside these vessels. *Common femoral vein, Common femoral artery and Great Saphenous vein* - This is the **most commonly referenced \"Mickey Mouse Sign\"** in ultrasound, visualized in the **groin/femoral region**. - The **common femoral artery** forms the \"head\" and the **common femoral vein** and **great saphenous vein** (at its junction) form the \"ears.\" - This sign is important for **central venous access**, **femoral vessel assessment**, and **avoiding complications** during procedures. *Anterior tibial artery, Dorsalis pedis artery and Extensor hallucis tendon* - These structures are located in the **lower leg and foot**, not in a configuration that forms the Mickey Mouse sign. - They are important for assessing **peripheral vascular status** but do not constitute this specific ultrasound landmark. *Brachial artery, Basilic vein and Biceps tendon* - These are structures found in the **upper arm**. - While important for upper extremity vascular imaging, they do not form the \"Mickey Mouse Sign\" pattern on ultrasound.

Question 6: Which one of the following statements is correct regarding eFAST in trauma? 1. It is a technique to assess free fluid in abdominal cavity, thoracic cavity, and pericardium. 2. It is a technique to assess free fluid in pelvic cavity. 3. It is a technique to assess free fluid in pleural cavity. Select the correct answer using the code given below:

A. 1, 2 and 3 (Correct Answer)
B. 1 and 2 only
C. 2 and 3 only
D. 1 and 3 only

Explanation: ***1, 2 and 3*** - The **eFAST exam (extended Focused Assessment with Sonography for Trauma)** evaluates multiple areas for **free fluid**, including the abdominal cavity, thoracic cavity (pleural effusions), and pericardium (pericardial effusions). - It also includes specific views for the **pelvic cavity** (pouch of Douglas) to detect free fluid, which is highly relevant in trauma settings. *1 and 2 only* - This option misses the crucial component of assessing the **pleural cavity** for free fluid (hemothorax), which is an integral part of the **eFAST protocol**. - While it correctly includes the abdominal and pelvic cavities, the exclusion of the thoracic cavity (pleural) makes it incomplete. *2 and 3 only* - This option incorrectly omits the assessment of the **abdominal cavity**, which is a primary and essential part of any FAST or eFAST exam to identify intra-abdominal hemorrhage. - The abdominal cavity includes views of the **hepatorenal space (Morison's pouch)**, **splenorenal space**, and **suprapubic window**. *1 and 3 only* - This option incorrectly excludes the specific assessment of the **pelvic cavity**, which is routinely included in the eFAST exam, particularly in trauma, to identify dependent pooling of free fluid. - While it correctly includes the abdominal and thoracic cavities, the absence of the pelvic cavity assessment makes it incomplete.