Yes, the MRI findings fully explain her symptoms.
The small recent infarct in the left centrum semiovale identified on MRI directly accounts for this patient's acute left arm and leg weakness and numbness, confirming an acute ischemic stroke rather than TIA. The centrum semiovale is a critical white matter region containing descending motor fibers from the right motor cortex, and a lesion here characteristically produces contralateral (left-sided) hemiparesis affecting both arm and leg 1, 2.
Anatomic Correlation
The imaging findings demonstrate clear anatomic-clinical correlation:
- Left centrum semiovale infarct → explains contralateral (left) arm and leg symptoms through disruption of corticospinal tract fibers
- No hemorrhage → confirms ischemic rather than hemorrhagic etiology
- CTA findings show questionable stenosis in right MCA branch (contralateral to symptoms) and no large vessel occlusion, suggesting either small vessel disease or embolic mechanism with recanalization
Diagnostic Confirmation
This case illustrates why MRI with diffusion-weighted imaging is superior to CT for acute stroke diagnosis 1, 2. The initial CT was negative (as expected in hyperacute stroke), but MRI detected the acute infarct. Research demonstrates that MRI has 93% sensitivity for ischemic stroke when excluding TIA patients, with 96% specificity 3.
Critical timing consideration: The MRI was appropriately obtained early. Studies show that 30% of patients with negative scans at 90 days had clearly identifiable strokes on baseline MRI, and delayed imaging reduces diagnostic yield by one-third 4. This patient's early MRI captured the acute lesion that might have been missed with delayed imaging.
Clinical Implications
This is a completed stroke, not a TIA, because:
- Acute infarction is visible on MRI
- Symptoms persisted long enough for imaging
- DWI-positive lesions in patients with transient symptoms confirm vascular origin and predict high stroke recurrence risk 5, 6
The background chronic microangiopathic changes and lacunar infarcts indicate pre-existing small vessel disease, placing her at elevated long-term stroke risk (12.5% at 5 years, 19.8% at 10 years) 7.
Management Priorities
The appropriate imaging workup was completed per guidelines 1, 2:
- ✓ Noncontrast imaging to exclude hemorrhage
- ✓ Vascular imaging (CTA) to assess for large vessel occlusion or high-grade stenosis
- ✓ MRI to define infarct extent
The questionable right MCA branch stenosis on CTA warrants further evaluation with either repeat CTA, MRA, or conventional angiography to determine if this represents a symptomatic stenosis requiring intervention, though the small vessel location and pattern suggest small vessel/lacunar mechanism is more likely 6, 8.