Detection of Intraparenchymal Hemorrhage After Endovascular Therapy in Patients with Acute Ischemic Stroke Using Immediate Postprocedural Flat-Panel Computed Tomography Scan

PURPOSE: To assess the diagnostic value of parenchymal hyperdense lesions visualized on the flat-panel CT scan in detecting/excluding intraparenchymal hemorrhage (IPH) after the endovascular treatment of acute stroke patients. METHODS: Two separate cohorts of acute ischemic stroke patients who underwent endovascular treatment were evaluated. In the first group, patients were evaluated for hyperdense parenchymal lesions immediately after the treatment with flat-panel CT scan; whereas, in the second group, patients underwent multidetector CT scan post procedure. IPH was defined as hyperdensity that persisted for >24 hours on follow up CT scan. RESULTS: A total of 30 patients were evaluated with flat panel, and 135 with multidetector CT scan immediately after the endovascular treatment. Hyperdense lesions were visualized on 7/30 (23%) of those evaluated with flat-panel CT versus 74/135 (55%) of those evaluated with multidetector CT scan. Based on 24-hour follow up imaging, hyperdense parenchymal lesions on immediate postprocedural flat-panel or multidetector CT studies had 100% sensitivity and negative predictive value for IPH; whereas, the specificity, and positive predictive value of such lesions were 88% and, 57% on the flat panel; and 53% and, 27% on the multidetector CT study, respectively. CONCLUSION: The absence of hyperdense lesions on immediate postprocedural flat-panel CT scan of ischemic stroke patients can exclude IPH with a high sensitivity and negative predictive value. The hyperdense parenchymal lesions visualized on flat-panel versus multidetector CT studies may have comparable sensitivity and negative predictive value for the detection of IPH.