Whole-brain CT perfusion: reliability and reproducibility of volumetric perfusion deficit assessment in patients with acute ischemic stroke

Abstract

Volumetric assessment in WB-CTP is reliable and reproducible. It might serve for a more accurate assessment of stroke outcome prognosis and definition of flow-volume mismatch. Time to drain showed the highest agreement and therefore might be an interesting parameter to define tissue at risk.

Perfusion Deficits and Mismatch in Patients with Acute Lacunar Infarcts Studied with Whole-Brain CT Perfusion

“…TTD is a recently introduced time-related perfusion parameter defined as the sum of the time from arterial enhancement to tissue enhancement and MTT. 25 Condensing both pathologic changes in contrast bolus delay time from arterial enhancement to tissue enhancement and tissue transit time, TTD describes the time of contrast medium washout and is very sensitive to all kinds of hemodynamic disturbances. 26 It has been argued that patients with true LIs should not have detectable perfusion deficits and/or that they should have no mismatch between infarcted tissue and hypoperfused tissue.…”

Crossed cerebellar diaschisis in patients with acute middle cerebral artery infarction: Occurrence and perfusion characteristics

“…The arterial input function was selected as described earlier. 19 Briefly, a vendor given algorithm was used to select a region of interest (ROI) within the earliest-appearing arteries at a representative slice at the level of the basal ganglia. The venous output region was selected from the superior sagittal sinus.…”

“…22,23 Final infarct volume was determined either on follow-up MR or on follow-up NECT using a volumetric approach as previously described. 19 Briefly, regions of interest around the infarct lesions were delineated on all relevant slices using OsiriX (OsiriX V.4.0 imaging software 2011) on a 27-in. iMac computer (Apple Inc., Cuperino, CA, USA).…”

Strategies of Collateral Blood Flow Assessment in Ischemic Stroke: Prediction of the Follow-Up Infarct Volume in Conventional and Dynamic CTA

“…OsiriX, Version 4.0, imaging software (http:// www.osirix-viewer.com) was used for 3D assessment of regions of hypoattenuation by using a method previously described for CT perfusion deficit assessment. 21 We manually segmented the region of hypoattenuation on every axial section of the temporal MIPs by using the OsiriX Closed Polygon Tool to create a region of interest; thus, the extent of the hypoattenuation could be evaluated by comparison with the contralateral hemisphere. Figure 2 shows representative examples.…”