Figure 1. Axial CT scan obtained in a 57-year-old man with a history of hypertension who presented with left hemiplegia and obtundation. A typical location for hypertensive SICH is demonstrated in the right basal ganglia.

Figure 2. Imaging studies obtained in a 26-year-old woman who presented with severe headache, vomiting, rapid progression to unconsciousness, and a blown left pupil. Left: Axial CT scan revealing a large left temporoparietooccipital SICH with midline shift. At craniotomy for emergency clot evacuation, an AVM was observed, but no attempt at resection was made. Right: Left vertebral artery angiogram obtained after clot evacuation confirmed a left posterior temporal AVM with a 2-cm nidus. Feeding arteries from the posterior cerebral artery and drainage into the transverse sinus are shown. The patient was allowed to recover from the initial hemorrhage and then underwent resection of the AVM 1 month later.

Figure 3. Neuroimaging studies acquired in a 4-year-old girl who presented with acute headache, vomiting, and seizures. Upper Left: Axial CT scan revealing a large right frontal SICH with subdural extension. Both MR imaging and angiography were negative for underlying tumor or vascular anomaly. The patient underwent craniotomy for clot evacuation, but no definitive diagnosis was established. Upper Center: Follow-up CT scan obtained 5 months after initial presentation is unremarkable except for demonstration of a small residual right frontal hypodensity. Upper Right: The patient returned 1 month later with progressive left hemiparesis and headache. An axial CT scan demonstrated a recurrent mixedattenuation right frontal hemorrhagic lesion. Lower Left: Further evaluation with coronal T₁-weighted MR imaging demonstrated a mixed–signal intensity right frontal hemorrhagic mass. Lower Center: Coronal enhanced T₁-weighted MR image revealing enhancement of the mass, suspicious for a hemorrhagic tumor. Lower Right: The patient underwent craniotomy for resection of the lesion. Examination of an intraoperative tissue specimen suggested a supratentorial primitive neuroectodermal tumor. A postoperative coronal enhanced T₁-weighted MR image demonstrated no obvious residual tumor.

Figure 4. Axial CT scans obtained in a 72-year-old woman who developed right hemiparesis after being hospitalized and undergoing heparin-based anticoagulation therapy for acute myocardial infarction. Left: The scan demonstrates a small left posterior frontal SICH. The heparin therapy was stopped and reversed with protamine. Right: A scan was obtained several hours later when the patient deteriorated neurologically. Significant hematoma enlargement is demonstrated. The patient subsequently died.

Figure 5. Axial CT scans acquired in a 78-year-old man receiving Coumadin for atrial fibrillation who presented with a right temporoparietal SICH. Initial coagulation parameters were a prothrombin time of 28, international normalized ratio of 2.8, and an activated partial thromboplastin time of 36; after a 90-µg/kg dose of recombinant activated factor VII, the values immediately corrected to, respectively, 9.6, 0.9, and 32. The patient then underwent an uncomplicated craniotomy for clot evacuation. Left: Noncontrast scan obtained at presentation. Center: Scan obtained on postoperative Day 1. Right: Follow-up scan obtained 6 weeks postoperatively.

Figure 6. Imaging studies obtained in a 19-year-old man with sudden- onset headache and rapidly progressive loss of consciousness. Left: Axial CT scan demonstrating a large left cerebellar hematoma with near-complete effacement of the fourth ventricle and an enlarged right temporal horn. The patient underwent emergency ventriculostomy and craniectomy for clot evacuation. A presumed AVM was identified at surgery. Right: Anteroposterior left vertebral artery angiogram confirming an AVM in the far-lateral aspect of the cerebellum. Following clot evacuation, the patient suffered multiple lower cranial nerve deficits and bilateral sixth nerve palsies, which improved markedly over time. Cognitive status normalized and he underwent resection of the AVM 6 weeks after initial presentation.

Figure 7. Imaging studies obtained in a 39-year-old woman who presented with sudden-onset severe headache, somnolence, and left hemiparesis. Left: Axial CT scan revealing a large right temporal SICH. Basal cistern SAH was not prominent, but the clot extended inferiorly to the temporal floor and sylvian fissure. These features, combined with the presence of intraventricular hemorrhage, should raise the suspicion of aneurysmal hemorrhage. Right: Three-dimensional CT angiogram confirming the presence of a right middle cerebral artery bifurcation aneurysm.

Figure 8. Axial CT scan acquired in an 82-year-old man with a history of hypertension who presented with headache, vomiting, and progressive deterioration in consciousness. A small left cerebellar SICH extending into the fourth ventricle is demonstrated. Obstructive hydrocephalus was successfully treated by ventriculostomy. The patient did not require evacuation of the hematoma and made a good recovery.