A 72-year-old woman with a history of hypertension and diabetes mellitus presents with acute onset of left-sided weakness and slurred speech. Non-contrast CT brain performed 2 hours after symptom onset shows a hyperdense lesion in the right putamen with extension into the internal capsule. There is no evidence of subarachnoid hemorrhage. Which imaging modality is most appropriate to assess the extent of the hematoma and detect any underlying structural lesion (such as an arteriovenous malformation or tumor)?

Explanation

## Clinical Scenario Analysis The patient presents with **acute intracerebral hemorrhage (ICH)** in the putamen — a classic hypertensive hemorrhage location. The clinical question is whether this is **primary hypertensive ICH** or **secondary ICH** due to an underlying lesion (arteriovenous malformation, cavernoma, tumor, or vasculitis). ## Role of Imaging in ICH Evaluation | Modality | Acute Phase (0–6 hrs) | Subacute Phase (6–48 hrs) | Chronic Phase (>48 hrs) | Lesion Detection | |---|---|---|---|---| | **Non-contrast CT** | First-line; detects blood | Hematoma evolution | Limited sensitivity | Poor for underlying lesions | | **MRI + SWI + contrast** | Not first-line (slower) | **Optimal for lesion detection** | Excellent; detects cavernomas, AVMs, tumors | **Excellent (95%+)** | | **CT perfusion** | Assesses ischemic penumbra | Not indicated for ICH | N/A | No role in lesion detection | | **Transcranial Doppler** | Bedside monitoring | Vasospasm screening | N/A | No diagnostic role | ## Why MRI with SWI and Contrast is Correct **Key Point:** MRI brain with **susceptibility-weighted imaging (SWI)** and **gadolinium-enhanced sequences** is the gold standard for: 1. **Detecting underlying structural lesions** in secondary ICH (AVM, cavernoma, tumor, aneurysm) 2. **Assessing hematoma extent** with superior soft-tissue contrast 3. **Identifying microhemorrhages** (SWI is exquisitely sensitive) 4. **Evaluating for vasculitis or amyloid angiopathy** (gradient echo shows microhemorrhages) **Clinical Pearl:** In **lobar ICH** (cortical/subcortical) in elderly patients, **cerebral amyloid angiopathy** is a common cause. In **deep/basal ganglia ICH** in hypertensive patients, primary hypertensive ICH is most likely, but **underlying lesions must be excluded**. MRI is superior to CT for this purpose. **High-Yield:** ICH imaging algorithm: - **Acute phase (0–6 hrs)**: Non-contrast CT (rule out SAH, mass effect, hydrocephalus) - **Subacute phase (6–48 hrs)**: **MRI + SWI + contrast** (detect underlying lesion, assess for vasculitis, amyloid angiopathy) - **Follow-up**: Repeat imaging if clinical deterioration or if initial MRI inconclusive **Mnemonic: CAVEAT** — Causes of secondary ICH: - **C**erebral amyloid angiopathy (lobar, elderly) - **A**rteriovenous malformation - **V**asculitis - **E**ndovascular lesion (aneurysm) - **A**nticoagulation (warfarin, DOACs) - **T**umor