Vascular Access Ultrasound — MCQs
What is the next best step for a 22-year-old with a hepatic hemangioma on ultrasound?
Precise FNAC can be obtained by using:
MC late complication of central venous line is:
What is the primary instrument used for creating endodontic access cavity during endodontic procedures?
IVC filter is used in the following situations except -
Most common complication of cardiac catheterization is:
CECT is least useful as a diagnostic tool for:
A 40-year-old female was sent to the Radiology department for thyroid USG scan. Which probe will you use for thyroid scan?
The best material for below-inguinal arterial graft is:
In which of the following locations should the incision be made for the saphenous cutdown procedure in an obese patient with no visible or palpable superficial veins, requiring intravenous fluids in shock?
Vascular Access Ultrasound Indian Medical PG Practice Questions and MCQs
Question 1: What is the next best step for a 22-year-old with a hepatic hemangioma on ultrasound?
- A. Angiography
- B. CT
- C. Biopsy
- D. MRI (Correct Answer)
Explanation: ***MRI*** - **Magnetic Resonance Imaging (MRI)** is the most sensitive and specific imaging modality for confirming the diagnosis of a **hepatic hemangioma** due to its characteristic enhancement patterns. - An MRI with contrast (e.g., gadolinium) can definitively distinguish a hemangioma from other **benign or malignant liver lesions**, especially when the ultrasound findings are equivocal. *Angiography* - **Angiography** is an invasive procedure and is typically reserved for cases where **embolization** or surgical resection of a very large or symptomatic hemangioma is being considered. - It is not the initial diagnostic choice for confirming a suspected hemangioma identified on **ultrasound**. *CT* - A **CT scan** with contrast can also characterize a hemangioma, showing peripheral nodular enhancement followed by progressive centripetal fill-in. - However, **MRI** generally offers superior soft tissue contrast and provides more definitive diagnostic features for hemangiomas, particularly in younger patients where radiation exposure from CT is a concern. *Biopsy* - **Biopsy** of a suspected hepatic hemangioma is generally contraindicated due to the risk of **hemorrhage** and is rarely necessary for diagnosis. - Imaging characteristics (especially on MRI) are usually sufficient to confirm the diagnosis without the need for an invasive procedure.
Question 2: Precise FNAC can be obtained by using:
- A. CT
- B. MRI
- C. Endoscopic USG
- D. USG (Correct Answer)
Explanation: ***USG*** - **Ultrasound (USG)** guidance is the **most commonly used** modality for **fine needle aspiration cytology (FNAC)** due to its real-time imaging capabilities, allowing the operator to visualize the needle tip entering the lesion. - It is particularly useful for superficial lesions or those with a clear acoustic window, offering good **spatial resolution**, wide availability, no radiation exposure, and accessibility for most body regions. - USG provides excellent precision for routine FNAC procedures across various clinical settings. *CT* - **Computed tomography (CT)** provides excellent anatomical detail and is useful for guiding FNAC in deeper or more complex lesions within the body cavity (e.g., lungs, retroperitoneum). - However, it involves **ionizing radiation** and, unlike USG, does not offer real-time visualization of the needle path, requiring intermittent scanning. *MRI* - **Magnetic resonance imaging (MRI)** offers superior soft tissue contrast and is excellent for visualizing certain lesions, but it is less commonly used for routine FNAC guidance. - The high cost, long scan times, and challenges with MRI-compatible needles make it less practical for real-time guidance compared to USG or CT. *Endoscopic USG* - **Endoscopic ultrasound (EUS)** is highly effective for precise FNAC of lesions adjacent to the gastrointestinal tract (e.g., pancreas, mediastinum, submucosal lymph nodes) as it provides high-resolution imaging from within. - While very precise for its specific indications, it is an invasive procedure requiring endoscopy and is not suitable for all body regions like routine superficial or transthoracic biopsies where the question is generally referring to.
Question 3: MC late complication of central venous line is:
- A. Sepsis (Correct Answer)
- B. Thromboembolism
- C. Cardiac arrhythmias
- D. Air embolism
Explanation: **Sepsis** - **Catheter-related bloodstream infections (CRBSIs)** are the most common late complication of central venous lines, leading to sepsis [1]. - The risk of sepsis increases with the **duration** of catheter placement, frequency of line access, and inadequate aseptic technique [1]. *Air embolism* - An **air embolism** is typically an immediate or early complication during insertion or removal of the central line, or connection/disconnection of administration sets. - It is not considered a late complication as it occurs due to a sudden entry of air into the venous system. *Thromboembolism* - While **thrombosis** can complicate central venous lines, leading to potential thromboembolism, it is less common than sepsis as a late complication [2]. - The formation of a thrombus is often localized to the catheter tip or vessel wall and may or may not lead to a symptomatic embolism [2]. *Cardiac arrhythmias* - **Cardiac arrhythmias** can occur during central venous line insertion if the guidewire or catheter tip irritates the myocardium, making it an immediate or early complication. - This is usually a transient event and not a long-term or late complication associated with the mere presence of the catheter.
Question 4: What is the primary instrument used for creating endodontic access cavity during endodontic procedures?
- A. K-File
- B. K-reamer
- C. Gates glidden drill
- D. Round bur (Correct Answer)
Explanation: ***Round bur*** - A **round bur** is the primary choice for creating the initial opening of the access cavity due to its ability to create a smooth, rounded entry point and remove caries effectively. - Its design allows for controlled penetration into the tooth and the removal of the **pulp chamber roof**, which is crucial for endodontic access. *Gates Glidden drill* - **Gates Glidden drills** are primarily used for widening the coronal portion of the root canal, not for creating the initial access cavity. - They are designed to be used in a **crown-down technique** to remove restrictive dentin in the canal's orifice. *K-File* - **K-files** are hand instruments used for initial negotiation, enlargement, and cleaning of the root canal system, not for creating the access cavity. - They are characterized by their **tightly twisted square or triangular cross-sectional blades**, which facilitate cutting and debris removal inside the canal. *K-reamer* - **K-reamers** are primarily used for shaping and enlarging the root canals through a reaming, or rotational, motion. - Similar to files, they are designed to work within the canal space and are not suitable for the initial opening of the **access cavity**.
Question 5: IVC filter is used in the following situations except -
- A. To reduce symptoms
- B. As primary treatment for acute DVT (Correct Answer)
- C. Negligible size of emboli
- D. To prevent progress of native blood vessel disease
Explanation: ***As primary treatment for acute DVT*** - The **primary treatment** for **acute deep vein thrombosis (DVT)** is **anticoagulation therapy** (heparin, warfarin, or DOACs) to prevent clot propagation and embolization. - An **IVC filter** is **NOT primary therapy**—it is reserved for specific situations and does not treat the underlying thrombosis. - **Indications for IVC filter include:** - Absolute **contraindication to anticoagulation** (active bleeding, recent hemorrhagic stroke) - **Recurrent PE despite adequate anticoagulation** - Complications from anticoagulation therapy - Therefore, using IVC filter as primary treatment for acute DVT is **incorrect and not indicated**. *Negligible size of emboli* - While IVC filters trap **large emboli**, the concept of "negligible size emboli" is not a standard clinical consideration for filter placement. - IVC filters are indicated based on **risk of PE** and **contraindications to anticoagulation**, not based on emboli size assessment. *To reduce symptoms* - **IVC filters** do not reduce symptoms of DVT such as pain, swelling, or discomfort. - They function as a **mechanical barrier** to prevent emboli from reaching pulmonary circulation. - Symptom management requires anticoagulation, compression therapy, and leg elevation. *To prevent progress of native blood vessel disease* - IVC filters do not influence progression of underlying **vascular disease** such as atherosclerosis or chronic venous insufficiency. - Their sole function is **mechanical prevention of PE**, not disease modification.
Question 6: Most common complication of cardiac catheterization is:
- A. Vascular Access Site Bleeding (Correct Answer)
- B. Arrhythmia
- C. Contrast reaction
- D. Perforation of heart chamber
Explanation: ***Vascular Access Site Bleeding*** - This is the **most common complication** of cardiac catheterization, occurring in 2-6% of procedures due to the invasive nature of puncturing an artery or vein for catheter insertion. - Complications can range from a **small hematoma or bruising** to more serious issues like pseudoaneurysm formation or arteriovenous fistula. - Risk factors include larger sheath size, anticoagulation, and femoral access (compared to radial access). *Arrhythmia* - While rhythm disturbances can occur during catheterization, especially when the catheter irritates the myocardium, they are **less frequent** than access site complications. - Most arrhythmias are **transient** and resolve spontaneously without intervention. - Common types include PVCs, NSVT, and rarely sustained ventricular arrhythmias. *Contrast reaction* - Reactions to contrast media can occur, ranging from mild (e.g., rash, itching) to severe (e.g., anaphylaxis). - However, with modern non-ionic, low-osmolar contrast agents and careful patient screening, these are **not the most common complications**. - Incidence of severe reactions is less than 0.1% with modern agents. *Perforation of heart chamber* - This is a **rare but serious complication** (incidence <0.1%) that can lead to cardiac tamponade. - It is typically associated with complex procedures, stiff guidewires, or difficult anatomical features. - Its incidence is significantly lower than access site bleeding.
Question 7: CECT is least useful as a diagnostic tool for:
- A. Glomus jugulare
- B. Carotid body tumor
- C. Juvenile angiofibroma
- D. Subclavian steal syndrome (Correct Answer)
Explanation: ***Correct: Subclavian steal syndrome*** - **Doppler ultrasound** is the primary and most effective diagnostic method for real-time assessment of blood flow velocity and direction in the vertebral and subclavian arteries, directly demonstrating the **"steal" phenomenon** - While **Computed tomography angiography (CTA)** with contrast can visualize the subclavian artery anatomy, it is **not optimal** for evaluating the hemodynamic flow dynamics that define this condition - The diagnosis relies on demonstrating **reversed vertebral artery flow**, which is best assessed with duplex Doppler ultrasound *Incorrect: Glomus jugulare* - **CECT is highly useful** for identifying the characteristic **vascular nature** and **bone erosion** associated with glomus jugulare tumors in the temporal bone - CECT allows for detailed visualization of tumor extent, particularly its relationship to surrounding structures and bony labyrinth - Shows intense enhancement due to the highly vascular nature of this paraganglioma *Incorrect: Carotid body tumor* - **CECT is highly effective** in diagnosing carotid body tumors, which are paragangliomas with **hypervascularity** leading to intense contrast enhancement - Provides excellent anatomical detail, showing the characteristic **splaying of the carotid bifurcation** (Lyre sign) - Clearly demonstrates tumor vascularity and relationship to great vessels *Incorrect: Juvenile angiofibroma* - **CECT is crucial** for diagnosing and staging juvenile angiofibromas, which are **highly vascular tumors** of the nasopharynx that show avid contrast enhancement - Helps delineate the tumor's extent, including involvement of the pterygopalatine fossa, sphenoid sinus, and potential intracranial extension - Essential for pre-operative planning due to the tumor's vascularity
Question 8: A 40-year-old female was sent to the Radiology department for thyroid USG scan. Which probe will you use for thyroid scan?
- A. Linear (Correct Answer)
- B. Curvilinear
- C. Endocavitary
- D. Phase array
Explanation: ***Linear*** - A **linear probe** is ideal for scanning superficial structures like the thyroid gland due to its high-frequency transducers, which provide excellent **spatial resolution** for structures close to the skin surface. - This probe type yields a **rectangular field of view**, allowing for detailed imaging of the thyroid's fine anatomy and any subtle nodules or abnormalities. *Curvilinear* - A **curvilinear probe** uses a lower frequency, which offers better **penetration depth** but at the cost of spatial resolution, making it suitable for deeper abdominal or pelvic organs. - Its **curved footprint** produces a wider, sector-shaped field of view, which is less optimal for the detailed assessment of a superficial organ like the thyroid. *Endocavitary* - An **endocavitary probe** is specifically designed for intracavitary examinations, such as transvaginal or transrectal ultrasound, providing high-resolution images of internal structures not accessible externally. - Its specialized shape and frequency are entirely unsuitable for surface scanning of the thyroid gland. *Phase array* - A **phase array probe** is characterized by a small footprint and the ability to electronically steer the ultrasound beam, making it ideal for cardiac imaging or transcranial doppler studies where a small acoustic window is present. - While it can achieve good depth penetration, its primary application and image quality profile are not optimized for superficial, high-resolution imaging of organs like the thyroid.
Question 9: The best material for below-inguinal arterial graft is:
- A. Saphenous vein graft (upside-down) (Correct Answer)
- B. Cryopreserved vein
- C. Dacron
- D. PTFE
Explanation: ***Saphenous vein graft (upside-down)*** - The **autologous saphenous vein** is the material of choice for below-inguinal arterial bypasses due to its superior patency rates compared to synthetic grafts. - It is often harvested and implanted **'upside-down' (reversed)** to ensure the valves do not obstruct blood flow, or can be used *in situ* after rendering the valves incompetent. - Five-year patency rates for autologous vein grafts exceed 70-80% for femoropopliteal bypasses. *Cryopreserved vein* - **Cryopreserved saphenous vein allografts** are an alternative when autologous vein is unavailable or inadequate. - However, they have **significantly lower patency rates** compared to autologous vein grafts due to immunological responses and structural degradation. - They are generally reserved for salvage situations or as a bridge in limb-threatening ischemia. *Dacron* - **Dacron (polyethylene terephthalate)** grafts are primarily used for large-diameter arterial replacements, such as in **aortic bypasses**, and are less suitable for smaller, high-resistance vessels below the inguinal ligament. - They tend to have higher rates of **thrombosis** and infection when used in infra-inguinal positions compared to vein grafts. *PTFE* - **Polytetrafluoroethylene (PTFE)** grafts have lower patency rates than autologous vein grafts, particularly in smaller diameter vessels and below-knee positions, due to issues like **intimal hyperplasia** at the anastomoses. - While suitable when autologous vein is unavailable, it is generally considered inferior for below-inguinal peripheral arterial disease, with 3-year patency rates around 50-60% for above-knee and 30-40% for below-knee positions.
Question 10: In which of the following locations should the incision be made for the saphenous cutdown procedure in an obese patient with no visible or palpable superficial veins, requiring intravenous fluids in shock?
- A. Anterior to the medial malleolus (Correct Answer)
- B. Posterior to the lateral malleolus
- C. Anterior to the lateral malleolus
- D. On the dorsum of the foot
Explanation: ***Anterior to the medial malleolus*** - The **greater saphenous vein** consistently runs anterior, one finger breadth to the medial malleolus, making this a reliable site for incision even when veins are not visible or palpable, particularly in **obese patients** or those in shock. - This location allows for direct access to a relatively large vein, crucial for rapid **intravenous fluid administration** in an emergency. *Posterior to the lateral malleolus* - This location is typically associated with the **small saphenous vein**, which is generally smaller and more variable in its superficial course, making it less dependable for cutdown in an emergent situation. - Incision here carries a higher risk of damaging the **sural nerve**, leading to sensory deficits. *Anterior to the lateral malleolus* - The veins in this region are usually smaller and less surgically significant for a **saphenous cutdown** required for rapid fluid infusion. - Accessing a suitable vein here is often more challenging and time-consuming, especially in an obese patient. *On the dorsum of the foot* - While veins on the **dorsum of the foot** are commonly used for routine IV access, they are smaller and more prone to collapse during shock, making them inadequate for rapid, high-volume fluid resuscitation. - The superficial location also makes them more susceptible to accidental dislodgement during patient movement.
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