Optimal Perfusion Computed Tomographic Thresholds for Ischemic Core and Penumbra Are Not Time Dependent in the Clinically Relevant Time Window

• Published in: Stroke (1970) Vol. 45; no. 5; pp. 1355 - 1362
• Main Authors: Qiao, Yujie, Zhu, Guangming, Patrie, James, Xin, Wenjun, Michel, Patrik, Eskandari, Ashraf, Jovin, Tudor, Wintermark, Max
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Heart Association, Inc 01.05.2014; Lippincott Williams & Wilkins
• Subjects: Aged; Biological and medical sciences; Brain Ischemia - classification; Brain Ischemia - pathology; Brain Ischemia - physiopathology; Cardiovascular system; Contrast Media - administration & dosage; Databases, Factual; Female; Follow-Up Studies; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Neurology; Perfusion Imaging - instrumentation; Perfusion Imaging - methods; Predictive Value of Tests; Retrospective Studies; Stroke - classification; Stroke - pathology; Stroke - physiopathology; Time Factors; Tomography, X-Ray Computed; Ultrasonic investigative techniques; Vascular diseases and vascular malformations of the nervous system; computed tomography; Stroke; Nervous system diseases; Radiodiagnosis; Cardiovascular disease; Cerebral disorder; Vascular disease; Perfusion imaging; Central nervous system disease; Medical imagery; Computerized axial tomography; Ischemic penumbra; Cerebrovascular disease; perfusion imaging; stroke
• ISSN: 0039-2499; 1524-4628
• DOI: 10.1161/STROKEAHA.113.003362

BACKGROUND AND PURPOSE—This study aims to determine whether perfusion computed tomographic (PCT) thresholds for delineating the ischemic core and penumbra are time dependent or time independent in patients presenting with symptoms of acute stroke. METHODS—Two hundred seventeen patients were evaluated in a retrospective, multicenter study. Patients were divided into those with either persistent occlusion or recanalization. All patients received admission PCT and follow-up imaging to determine the final ischemic core, which was then retrospectively matched to the PCT images to identify optimal thresholds for the different PCT parameters. These thresholds were assessed for significant variation over time since symptom onset. RESULTS—In the persistent occlusion group, optimal PCT parameters that did not significantly change with time included absolute mean transit time, relative mean transit time, relative cerebral blood flow, and relative cerebral blood volume when time was restricted to 15 hours after symptom onset. Conversely, the recanalization group showed no significant time variation for any PCT parameter at any time interval. In the persistent occlusion group, the optimal threshold to delineate the total ischemic area was the relative mean transit time at a threshold of 180%. In patients with recanalization, the optimal parameter to predict the ischemic core was relative cerebral blood volume at a threshold of 66%. CONCLUSIONS—Time does not influence the optimal PCT thresholds to delineate the ischemic core and penumbra in the first 15 hours after symptom onset for relative mean transit time and relative cerebral blood volume, the optimal parameters to delineate ischemic core and penumbra.