Does a patient with right arm weakness and numbness, and a CT head showing possible left MCA insular branch thrombosis, need to be evaluated by a neurointerventional radiologist (neuro IR)?

Acute Stroke with Suspected MCA Thrombosis: Urgent Neurointerventional Evaluation Required

Yes, this patient requires immediate evaluation by neurointerventional radiology (neuro IR) for potential endovascular thrombectomy, as the clinical presentation of acute focal neurologic deficit with suspected large vessel occlusion represents a time-critical emergency where outcomes depend entirely on rapid reperfusion.

Immediate Clinical Context

This patient presents with:

• Right arm weakness and numbness indicating left hemisphere involvement 1
• CT finding of left MCA insular branch hyperdensity suggesting acute thrombosis 2
• Acute focal neurologic deficit requiring emergent vascular imaging and intervention consideration 2

The hyperdense vessel sign on non-contrast CT is a critical finding that indicates acute thrombus within the vessel, even when described as "possible artifact" 2. This radiographic sign has high specificity for acute arterial occlusion and should never be dismissed without further vascular imaging 2.

Time-Critical Management Algorithm

Step 1: Immediate Vascular Imaging (Within Minutes)

• CT angiography (CTA) of the head and neck should be obtained immediately after the non-contrast CT to confirm vessel occlusion and assess collateral circulation 2
• CTA is rated as "usually appropriate" (rating 8/9) for new focal neurologic deficits and can be performed immediately following non-contrast CT 2
• MR angiography is an alternative if CTA is contraindicated, though CTA is faster in the emergency setting 2

Step 2: Determine Thrombectomy Eligibility

• If large vessel occlusion is confirmed on CTA, immediate neuro IR consultation is mandatory 3
• The patient presenting with acute symptoms and suspected MCA occlusion falls within the therapeutic window for mechanical thrombectomy 2
• Time to reperfusion is the single most critical determinant of outcome in acute large vessel occlusion 3

Step 3: Concurrent Medical Management

• Maintain systolic blood pressure ≥100 mmHg to preserve cerebral perfusion pressure 2
• Avoid hypotension (SBP <90 mmHg), which is associated with unfavorable neurological outcomes 2
• Do not delay vascular imaging or neuro IR consultation for additional medical optimization 3

Critical Pitfalls to Avoid

Never dismiss hyperdense vessel signs as "artifact" without confirmatory vascular imaging. The ACR Appropriateness Criteria explicitly state that parenchymal brain imaging must be accompanied by CT or MR vascular imaging of the head and neck in patients with new focal neurologic deficits 2. The hyperdense MCA sign has high specificity for acute thrombus, and failure to pursue this finding with CTA/CTA could result in a missed opportunity for life-saving intervention 2.

Do not wait for MRI if it delays treatment. While MRI with diffusion-weighted imaging is more sensitive than CT for acute infarct detection, non-contrast CT followed by CTA is the fastest pathway to identifying candidates for thrombectomy 2. CT is "usually appropriate" (rating 9/9) as the initial study for patients with new focal neurologic deficits presenting within 6 hours 2.

Recognize that "artifact vs. thrombosis" language in radiology reports requires immediate clarification. When a radiologist cannot exclude thrombosis, the clinical team must assume thrombosis is present until proven otherwise with vascular imaging 2. The stakes are too high to adopt a "wait and see" approach.

Why Neuro IR Consultation Cannot Wait

• Endovascular thrombectomy is the standard of care for large vessel occlusions when patients present within the therapeutic window 2
• Catheter angiography may be appropriate (rating 5/9) for definitive diagnosis and treatment in acute stroke with fixed or worsening deficits 2
• Outcome depends entirely on time to reperfusion - every minute of delay increases disability and mortality 3
• The patient's symptoms (unilateral arm weakness and numbness) combined with imaging findings of possible MCA occlusion create a high pretest probability for large vessel occlusion requiring mechanical intervention 2, 3

Recommended Immediate Actions

1. Activate stroke code and notify neuro IR team immediately 3
2. Obtain CTA head and neck within the next 15-30 minutes 2
3. Maintain blood pressure ≥100 mmHg systolic 2
4. Prepare for possible thrombectomy - ensure IV access, NPO status, and coagulation parameters are available 2
5. Do not administer antiplatelet agents until hemorrhage is excluded and thrombectomy candidacy is determined 3

The combination of acute focal neurologic deficit and radiographic evidence suggesting arterial occlusion mandates urgent neuro IR evaluation, as this represents one of the few true neurologic emergencies where minutes matter for functional outcome 2, 3.