Vascular Emergencies — MCQs
Which of the following is not a branch of the inferior mesenteric artery?
Best imaging modality for acute pulmonary embolism
Which finding is NOT associated with pulmonary embolism on CT angiography?
The CT thorax image shows:
A 50-year-old man suddenly developed right-sided weakness and aphasia within 2 hours. His BP recorded was 160/110mmHg and NCCT was clear. What is the next step in management?
Most specific finding of acute stroke on CT
What is the Investigation of Choice (IOC) for Acute Aortic Dissection?
Which is the best test to detect pulmonary embolism?
Which of the following is shown in the image below?
A 35-year-old male with history of 4 weeks of immobilization for fracture of femur develops sudden onset breathlessness and blood in sputum. CT angiography shows? (Recent NEET Pattem 2018-19)
Vascular Emergencies Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is not a branch of the inferior mesenteric artery?
- A. Left colic
- B. Middle rectal (Correct Answer)
- C. Superior rectal
- D. Sigmoidal artery
Explanation: ***Middle rectal artery*** - The **middle rectal artery** [2] is typically a branch of the **internal iliac artery** [2], supplying the middle part of the rectum. - It is not a direct branch of the inferior mesenteric artery. *Left colic artery* - The left colic artery is a direct branch of the **inferior mesenteric artery** [1], supplying the distal transverse colon and descending colon. - It forms an important anastomosis with the middle colic artery [1]. *Superior rectal artery* - The **superior rectal artery** is the terminal branch of the **inferior mesenteric artery**, supplying the upper rectum. - This artery provides the primary arterial supply to the proximal large intestine structures. *Sigmoidal artery* - The **sigmoidal arteries** are typically 2-4 branches arising from the **inferior mesenteric artery**, supplying the sigmoid colon. - These arteries anastomose with branches of the superior rectal and left colic arteries.
Question 2: Best imaging modality for acute pulmonary embolism
- A. V/Q scan
- B. CT pulmonary angiogram (Correct Answer)
- C. Chest X-ray
- D. MRI
Explanation: ***CT pulmonary angiogram*** - This is the **gold standard** imaging modality for diagnosing acute pulmonary embolism due to its high sensitivity and specificity in visualizing pulmonary arteries. - It rapidly provides detailed images of the pulmonary vasculature, allowing for direct visualization of **thrombi**. *V/Q scan* - A **V/Q scan** measures ventilation and perfusion of the lungs and is less definitive than CTPA, especially in patients with pre-existing lung disease. - It is often considered when **CTPA is contraindicated**, such as in cases of severe renal impairment or contrast allergy. *Chest X-ray* - A **chest X-ray** is generally used to rule out other causes of chest pain and shortness of breath, such as pneumonia or pneumothorax, rather than to diagnose PE directly. - It has **low sensitivity and specificity** for pulmonary embolism, as findings are often non-specific or normal even in the presence of PE. *MRI* - **Magnetic resonance angiography (MRA)** can be used, but it is typically reserved for patients who cannot undergo CTPA or V/Q scan due to contraindications like **pregnancy** or **renal failure**. - It often takes longer to perform and has lower spatial resolution compared to CTPA for pulmonary artery visualization.
Question 3: Which finding is NOT associated with pulmonary embolism on CT angiography?
- A. Filling defects
- B. Hampton's hump (Correct Answer)
- C. Enlarged pulmonary artery
- D. Oligemia
Explanation: ***Hampton's hump*** - **Hampton's hump** is a **peripheral wedge-shaped opacity** representing **pulmonary infarction**, classically described as a **chest X-ray finding**, not a primary CT angiography (CTA) finding. - While the parenchymal opacity from infarction can be visualized on CT, it is **not what CTA is designed to detect**—CTA primarily visualizes the **pulmonary vasculature and intraluminal thrombi**. - Hampton's hump reflects a **consequence** of PE (tissue infarction) rather than the embolus itself, making it **NOT directly associated with PE on CTA**. *Filling defects* - **Filling defects** represent **intraluminal thrombus** within contrast-filled pulmonary arteries. - This is the **hallmark and primary diagnostic sign** of pulmonary embolism on CT angiography. - CTA is specifically performed to visualize these vascular abnormalities. *Enlarged pulmonary artery* - An **enlarged main pulmonary artery** (>29 mm) is a **secondary finding** on CTA that suggests **pulmonary hypertension**. - This can result from acute massive PE or chronic thromboembolic disease. - It is readily visualized and measured on CTA as part of PE assessment. *Oligemia* - **Oligemia (Westermark sign)** refers to **regional decreased vascularity** distal to a significant pulmonary artery obstruction. - While classically a **chest X-ray finding**, decreased vessel caliber and perfusion changes **can be appreciated on CTA**. - Unlike Hampton's hump (a parenchymal consequence), oligemia reflects the **vascular effect** of the obstruction and is thus more directly related to CTA findings.
Question 4: The CT thorax image shows:
- A. Descending aortic dissection
- B. Aortic aneurysm
- C. Ascending aortic dissection (Correct Answer)
- D. Aortic coarctation
Explanation: ***Ascending aortic dissection*** - The CT image shows a **classic intimal flap** separating the true and false lumens in the ascending aorta, which is the hallmark feature of an aortic dissection. - This represents a **Stanford Type A dissection** involving the ascending aorta, which is a life-threatening emergency requiring **immediate surgical intervention** due to high risk of complications including rupture, cardiac tamponade, and acute aortic regurgitation. - The presence of the intimal flap creating two distinct channels (true and false lumens) is pathognomonic for dissection. *Descending aortic dissection* - While the intimal flap is characteristic of dissection, the image specifically shows involvement of the **ascending aorta** (proximal to the left subclavian artery), not the descending thoracic aorta. - Descending aortic dissections (Stanford Type B) are typically managed **medically** with blood pressure control, unlike ascending dissections which require surgery. *Aortic aneurysm* - An **aortic aneurysm** represents focal dilatation of the aortic wall (>50% increase in diameter) without separation of the intimal layers. - While aneurysms can be a risk factor for dissection, the key finding here is the **intimal flap dividing the lumen**, which defines dissection rather than simple aneurysmal dilatation. - The image does not show the uniform circumferential enlargement typical of aneurysms. *Aortic coarctation* - **Aortic coarctation** is a congenital narrowing of the aorta, typically located at the aortic isthmus (near the ligamentum arteriosum), distal to the left subclavian artery. - CT would show focal narrowing with pre-stenotic dilatation and collateral vessel formation, not an intimal flap. - This is a completely different pathology without the characteristic dissection flap seen in this image.
Question 5: A 50-year-old man suddenly developed right-sided weakness and aphasia within 2 hours. His BP recorded was 160/110mmHg and NCCT was clear. What is the next step in management?
- A. Tab labetalol 10 mg stat
- B. MRI brain with DWI
- C. Thrombolysis
- D. CT angiography to look for large vessel occlusion (Correct Answer)
Explanation: ***CT angiography to look for large vessel occlusion*** - The patient presents with **acute neurological deficits** (right-sided weakness and aphasia) occurring within 2 hours, making him a candidate for acute stroke intervention. A **clear NCCT** rules out hemorrhage but doesn't exclude an ischemic stroke [1]. - Given the acute onset and significant neurological deficits, it is crucial to determine if there is a **large vessel occlusion (LVO)** that could be treatable with endovascular thrombectomy, especially if the window for IV thrombolysis is closing or contraindicated [1]. *Tab labetalol 10 mg stat* - While the patient's **blood pressure is elevated (160/110 mmHg)**, aggressive lowering of blood pressure in acute ischemic stroke can worsen outcomes by reducing cerebral perfusion, especially before reperfusion strategies are initiated. - Blood pressure management guidelines for acute ischemic stroke without clear reperfusion options generally suggest allowing for higher blood pressure to maintain cerebral perfusion, unless it's excessively high (e.g., >220/120 mmHg or >185/110 mmHg if considering thrombolysis). *MRI brain with DWI* - **Diffusion-weighted imaging (DWI)** is highly sensitive for **acute ischemic changes** within minutes of onset and would confirm an ischemic stroke [2]. - However, in the hyperacute setting, especially with significant neurological deficits, the priority is to identify an LVO quickly for potential thrombectomy, which **CT angiography (CTA)** can provide more rapidly than MRI in many emergency settings [1]. *Thrombolysis* - **Intravenous thrombolysis** can be considered if the patient meets criteria, typically within **4.5 hours of symptom onset**. - While thrombolysis is a potential treatment, the **next most critical step** after ruling out hemorrhage in a potential LVO case is to identify the occlusion with CTA to determine eligibility for endovascular thrombectomy, which may be beneficial even beyond the IV thrombolysis window [1].
Question 6: Most specific finding of acute stroke on CT
- A. Sulcal effacement
- B. Hyperdense MCA sign (Correct Answer)
- C. Mass effect
- D. Loss of gray-white differentiation
Explanation: ***Hyperdense MCA sign*** - The **hyperdense middle cerebral artery (MCA) sign** is a direct visualization of a **thrombus** within the MCA, making it highly specific for an acute ischemic stroke caused by large vessel occlusion. - This sign indicates an acute arterial occlusion, which is key to early diagnosis and determining eligibility for **thrombolytic therapy**. *Sulcal effacement* - **Sulcal effacement** (loss of the normal grooves in the brain surface) may be an early sign of **brain edema** secondary to ischemia. - However, it is a non-specific finding and can be seen in other conditions causing brain swelling, such as trauma or infection. *Mass effect* - **Mass effect**, such as midline shift or effacement of ventricles, typically occurs later in the course of a large ischemic stroke due to significant edema. - In the acute phase, especially within the first few hours, mass effect is usually not evident, and its presence might suggest a different pathology or a more advanced stroke. *Loss of gray-white differentiation* - **Loss of gray-white differentiation** is an indirect sign of early cerebral ischemia, reflecting developing cytotoxic edema in the affected brain tissue. - While an important early indicator, it is less specific than the hyperdense MCA sign, as various acute brain injuries can cause similar changes.
Question 7: What is the Investigation of Choice (IOC) for Acute Aortic Dissection?
- A. USG
- B. Doppler
- C. CT-Angio (Correct Answer)
- D. MR-Angio
Explanation: ***CT-angio*** - **Computed tomography angiography (CTA)** is considered the **gold standard** imaging modality for diagnosing acute aortic dissection due to its rapid acquisition, wide availability, and excellent visualization of the aorta and its branches. - It precisely demonstrates the **intimal flap**, true and false lumens, and assesses the extent of the dissection and involvement of major branch vessels. *Usg* - **Ultrasound (USG)**, specifically **transesophageal echocardiography (TEE)**, is highly sensitive and specific for proximal aortic dissections. - However, its utility is operator-dependent and it has limitations in visualizing the entire aorta, especially the distal descending aorta. *Doppler* - **Doppler ultrasound** is used to assess blood flow velocity and patterns within vessels. - While it can detect flow disturbances, it is not the primary imaging modality for diagnosing the anatomical extent and characteristics of an aortic dissection flap. *Mr-Angio* - **Magnetic resonance angiography (MRA)** provides excellent soft tissue contrast, no radiation exposure, and detailed anatomical information for aortic dissection. - However, it is often less accessible, time-consuming, and contraindicated in patients with certain metallic implants or claustrophobia, making it less ideal for an acute emergency setting compared to CTA.
Question 8: Which is the best test to detect pulmonary embolism?
- A. D dimer assay
- B. MRI
- C. Ventilation Perfusion scan
- D. CT with IV contrast (Correct Answer)
Explanation: ***CT with IV contrast*** - **CT pulmonary angiography (CTPA)** is the **gold standard** for diagnosing pulmonary embolism due to its high sensitivity and specificity [1]. - It directly visualizes the **pulmonary arteries** and can detect emboli, making it the most definitive imaging test [1]. *D dimer assay* - A **negative D-dimer** can effectively **rule out PE** in low-to-intermediate probability patients, but a positive result is non-specific and requires further investigation. - It is a screening test with **poor specificity** in many clinical situations, such as surgery, trauma, cancer, or pregnancy, where D-dimer levels can be elevated for other reasons. *MRI* - **Magnetic resonance angiography (MRA)** can be used for PE diagnosis, particularly in patients unable to receive iodinated contrast or radiation. - However, it has **lower spatial resolution** and is generally less available and slower than CTPA, making it a second-line option. *Ventilation Perfusion scan* - A **V/Q scan** measures airflow (ventilation) and blood flow (perfusion) in the lungs to detect mismatches suggestive of PE [1]. - While useful, particularly in patients with **renal insufficiency** or **contrast allergy**, it often yields indeterminate results and is less sensitive than CTPA for definitive diagnosis [1].
Question 9: Which of the following is shown in the image below?
- A. Westermark sign (Correct Answer)
- B. Palla sign
- C. Hampton hump
- D. Round pneumonia
Explanation: ***Westermark sign*** - This image displays a **dilated pulmonary artery proximal to an area of oligemia**, specifically noted in the upper right lung field, as indicated by the arrow. This finding is characteristic of the **Westermark sign**, which is suggestive of a **pulmonary embolism**. - The Westermark sign represents **distal collapse of the pulmonary vasculature** due to a reduction in blood flow, making the lung parenchyma appear unusually lucent compared to adjacent normal lung fields. *Palla sign* - The Palla sign refers to a **dilated right descending pulmonary artery** (interlobar artery) on a chest X-ray. While it is also associated with pulmonary embolism, the image prominently shows oligemia, the defining feature of the Westermark sign, not solely an enlarged artery. - This sign indicates **increased pulmonary artery pressure** due to the embolus, but the key feature in the provided image is the reduced vascularity distally, not just the proximal vessel size. *Hampton hump* - A Hampton hump is a **wedge-shaped pleural-based opacity** with a rounded convex border facing the hilum. - It results from a **pulmonary infarction** due to a large pulmonary embolus and is not visible in this image. *Round pneumonia* - Round pneumonia is a **circular or oval-shaped consolidation** that is typically seen in children and appears as a mass-like lesion. - It is an infectious process with consolidation of lung tissue and does not involve vascular abnormalities like oligemia, which is clearly depicted in the image.
Question 10: A 35-year-old male with history of 4 weeks of immobilization for fracture of femur develops sudden onset breathlessness and blood in sputum. CT angiography shows? (Recent NEET Pattem 2018-19)
- A. Acute cor-pulmonale (Correct Answer)
- B. Pulmonary oedema
- C. Aortic dissection
- D. Fat embolism
Explanation: ***Acute cor-pulmonale*** - **4 weeks of immobilization** is a major risk factor for **deep vein thrombosis (DVT)** leading to **pulmonary embolism (PE)** - **CT pulmonary angiography** is the gold standard investigation for PE, showing filling defects in pulmonary arteries - Massive or submassive PE causes acute **right ventricular strain** = **acute cor-pulmonale** - Clinical presentation of **sudden breathlessness** and **hemoptysis** is classic for pulmonary thromboembolism - The timing (4 weeks post-immobilization) fits thromboembolism, not fat embolism *Fat embolism* - Occurs **acutely within 24-72 hours** after long bone fracture (especially femur/tibia) - The **4-week delay** makes fat embolism extremely unlikely - Presents with **respiratory distress, petechial rash, and neurological symptoms** (Gurd's criteria) - CT findings show diffuse ground-glass opacities, not typical filling defects seen on CT angiography *Pulmonary oedema* - Caused by **left heart failure** or **ARDS**, showing bilateral interstitial and alveolar fluid - Would show diffuse bilateral infiltrates on imaging, not filling defects in pulmonary vessels - **Hemoptysis** is uncommon in cardiogenic pulmonary edema - No clear cardiac history or precipitant in this patient *Aortic dissection* - Involves a tear in the aortic intima with blood dissecting through the aortic wall - Presents with **sudden severe chest/back pain**, not primarily with hemoptysis - CT angiography would show **aortic flap and false lumen**, not pulmonary vascular abnormalities - Unrelated to femur fracture or prolonged immobilization
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