Parenchymal Hyperdensity on Computed Tomography After Intra-Arterial Reperfusion Therapy for Acute Middle Cerebral Artery Occlusion

Abstract

Background and Purpose-The purpose of the present study was to assess the incidence and clinical significance of the intraparenchymal hyperdense areas on the posttherapeutic CT scan just after intra-arterial reperfusion therapy. Methods-Seventy-seven patients with acute middle cerebral artery occlusion were studied prospectively with posttherapeutic CT. Hyperdense areas were classified into three groups: those in the lentiform nucleus, insular cortex and cerebral cortex. We investigated the incidence of hyperdense areas and hemorrhagic transformations and assessed whether location of hyperdense areas may play a role in the incidence of hemorrhagic transformations. We also evaluated correlation between early CT signs and hyperdense areas. Results-Forty-five hyperdense areas were seen in 37 of the 77 patients (48.1%): 19 of the 45 (42.2%) were confirmed to be hematomas themselves, 6 (13.4%) showed later conversion to petechial hemorrhages, and 20 (44.4%) showed rapid disappearance without hemorrhagic transformations. Eleven of the 37 patients (29.7%) had neurological worsening due to massive hematoma (symptomatic hemorrhage), whereas none of the 40 patients without hyperdense areas had symptomatic hemorrhage. The incidence of hemorrhage among hyperdense areas was significantly lower in the insular cortex than in the other 2 regions (PϽ0.01). On the other hand, hyperdense areas in the lentiform nucleus had a significantly higher incidence of neurological worsening (PϽ0.05). There was a significant correlation between early CT signs and hyperdense areas (PϽ0.0001). Conclusions-The presence of hyperdense areas was a significant risk factor for severe hemorrhagic transformations, although only 29.7% of patients with hyperdense areas had symptomatic hemorrhage. On the contrary, the absence of hyperdense areas was a reliable negative predictor for symptomatic hemorrhage.

Contrast Enhancement and Contrast Extravasation on Computed Tomography After Intra-Arterial Thrombolysis in Patients With Acute Ischemic Stroke

“…In contrast, all 7 patients with contrast extravasation, a hyperdense lesion with maximum HU Ͼ90 that persisted on follow-up CT scan, developed parenchymal hematoma with clinical deterioration. Nakano et al 7 reported that the rapid disappearance of hyperdense areas, which is analogous to contrast enhancement in this study, on early posttherapeutic CT scans was never associated with symptomatic hemorrhage.…”

“…6 Hemorrhagic transformation with deterioration of neurological symptoms is the major complication of intra-arterial thrombolytic therapy; a frequency between 10% and 15.4% has been observed. 2,4,5,7 After completion of angiography and thrombolytic therapy, a nonenhanced CT scan is usually performed to investigate the possibility of hemorrhagic lesion. In the literature, a hyperdense lesion seen on posttherapeutic, nonenhanced CT scans after intra-arterial thrombolysis has been described as either hemorrhage or extravasation of contrast medium given during angiographic procedures performed during thrombolysis.…”

“…CT findings and the clinical outcome of this hyperdense lesion have been described periodically. [7][8][9][10][11][12] However, the CT criteria of this lesion have not been established, and somewhat different clinical consequences have been reported in the literature.…”

Contrast Extravasation into an Acute Spontaneous Intracerebral Hematoma: Multidetector CT Angiographic Findings and Clinical Implications

“…Mericle et al (15) have suggested that extravasation of contrast medium could be defined as a hyperdense area with a maximal HU measurement over 90 and/or disappearance of the hyperdensity on a repeated CT obtained within 24 hours. Nakano et al (16) have described the rapidly clearing hyperdense areas as evidence of ex- travasation of the contrast medium. In the present study, contrast extravasation was measured between 90 and 100 HU in comparison with the surrounding blood clot where contrast extravasation measured 60 to 70 HU.…”

Neuroimaging in Patients with Abnormal Blood Glucose Levels

“…19 Patients receiving intraarterial reperfusion therapy for stroke can also show transient hyperattenuation of the lentiform and insular cortex secondary to interstitial contrast extravasation. 27 Finally, because the hyperdensities in diabetic patients with HC-HB may resolve slowly or persist for years, 28 these may reflect previous hyperglycemia-induced injury. MR imaging may also reveal abnormal putaminal signal with or without involvement of the caudate and globus pallidus.…”