Chronic Cerebrovascular Infarct Diagnosis

Key Imaging Distinctions

Encephalomalacia appears as well-defined hypodense areas with tissue loss and ex-vacuo dilatation of adjacent ventricles on CT, indicating a chronic infarct, according to the American College of Radiology 1, 2
CT can demonstrate parenchymal brain calcifications within old ischemic lesions, which are characteristic of chronic rather than acute infarcts, as noted by Autoimmunity Reviews 3, 4
The presence of encephalomalacia indicates completed infarction with tissue resorption that has occurred over an extended timeframe, as stated by the American College of Radiology 2

MRI is far more sensitive than CT for detecting acute infarcts, with 77% vs 16% sensitivity in the hyperacute period, making CT an unreliable tool for acute stroke diagnosis, according to the American College of Radiology 5
CT abnormalities in acute stroke typically show only 30% sensitivity in the first hours, whereas malacic changes represent the chronic sequelae visible weeks to months later, as reported by Stroke 6

When evaluating suspected acute stroke, normal or malacic findings on CT do not exclude acute ischemia and should prompt MRI with diffusion-weighted imaging if acute stroke is suspected, as recommended by the American College of Radiology 1, 5
The presence of encephalomalacia on CT indicates prior completed infarction and should trigger investigation for vascular risk factors and secondary stroke prevention, according to the American College of Radiology 2