Early cerebral infarction: gadopentetate dimeglumine enhancement.

Gadopentetate dimeglumine was administered prospectively to 50 patients who presented for magnetic resonance (MR) imaging within 2 weeks after a cortical cerebral infarction. Twenty-two patients (44%) were imaged within 3 days after clinical ictus. Abnormalities detected with gadopentetate dimeglumine enhancement were observed in 46 (92%) of 50 patients. Classic parenchymal enhancement was a late finding, observed in all patients (17 of 17) imaged at 7-14 days after infarction. Before this time, three additional phases of contrast material-related abnormalities were observed. Enhancement of vessels supplying the infarct ("intravascular enhancement sign") was the earliest finding, seen in 17 (77%) of 22 infarcts aged 1-3 days. From day 2 to day 6, abnormal enhancement of meninges adjacent to the infarct was frequently noted ("meningeal enhancement sign"). Finally, a transition phase that combined intravascular or meningeal enhancement with early parenchymal enhancement was seen from day 3 to day 6. Gadopentetate dimeglumine-enhanced MR imaging in early stroke reveals evidence of vascular engorgement and sluggish flow, which precede the development of classic parenchymal enhancement.