A 72-year-old hypertensive woman from Mumbai is found unresponsive at home. CT head shows a large hyperdense lesion in the right putamen measuring 4 × 3 cm with extension into the internal capsule. There is midline shift of 8 mm and compression of the right lateral ventricle. No subarachnoid blood is seen. What is the most appropriate next imaging study to assess prognosis and guide management?