A prospective, multicenter pilot study investigating the utility of flat detector derived parenchymal blood volume maps to estimate cerebral blood volume in stroke patients

Abstract

PurposeNewer flat panel angiographic detector (FD) systems have the capability to generate parenchymal blood volume (PBV) maps. The ability to generate these maps in the angiographic suite has the potential to markedly expedite the triage and treatment of patients with acute ischemic stroke. The present study compares FP-PBV maps with cerebral blood volume (CBV) maps derived using standard dynamic CT perfusion (CTP) in a population of patients with stroke.Methods56 patients with cerebrovascular ischemic disease at two participating institutions prospectively underwent both standard dynamic CTP imaging followed by FD-PBV imaging (syngo Neuro PBV IR; Siemens, Erlangen, Germany) under a protocol approved by both institutional review boards. The feasibility of the FD system to generate PBV maps was assessed. The radiation doses for both studies were compared. The sensitivity and specificity of the PBV technique to detect (1) any blood volume deficit and (2) a blood volume deficit greater than one-third of a vascular territory, were defined using standard dynamic CTP CBV maps as the gold standard.ResultsOf the 56 patients imaged, PBV maps were technically adequate in 42 (75%). The 14 inadequate studies were not interpretable secondary to patient motion/positioning (n=4), an injection issue (n=2), or another reason (n=8). The average dose for FD-PBV was 219 mGy (median 208) versus 204 mGy (median 201) for CT-CBV. On CT-CBV maps 26 of 42 had a CBV deficit (61.9%) and 15 (35.7%) had a deficit that accounted for greater than one-third of a vascular territory. FD-PBV maps were 100% sensitive and 81.3% specific to detect any CBV deficit and 100% sensitive and 62.9% specific to detect any CBV deficit of greater than one-third of a territory.ConclusionsPBV maps can be generated using FP systems. The average radiation dose is similar to a standard CTP examination. PBV maps have a high sensitivity for detecting CBV deficits defined by conventional CTP. PBV maps often overestimate the size of CBV deficits. We hypothesize that the FP protocol initiates PBV imaging prior to complete saturation of the blood volume in areas perfused via indirect pathways (ie, leptomeningeal collaterals), resulting in an overestimation of CBV deficits, particularly in the setting of large vessel occlusion.

Usefulness of Flat Detector CT Perfusion Images in the Diagnosis and Determination of the Therapeutic Strategy for Intracranial Vascular Occlusion as a Complication of Cerebral Angiography: Technical Note

“…1,4) FD-CTP imaging is not inferior in detection sensitivity for hypoperfused areas in actual patients with cerebral ischemia compared with the CBV determined using conventional multi-slice CT, 1) and the sizes of the hypoperfused areas judged by the two methods have been reported to be closely correlated. 4,6) Struffert et al reported that areas in which the CBV did not recover after acute phase revascularization eventually lapsed into cerebral infarction by a study of 16 patients with acute cerebral infarction using FD-CTP imaging.…”

“…[1][2][3][4] We could accurately evaluate the condition of a patient who developed embolism during cerebral angiography before surgery for brain tumor by performing flat detector CT perfusion (FD-CTP) study and prevent cerebral angiography by thrombectomy. This case is presented as it first demonstrated the usefulness of FD-CTP for troubleshooting during cerebral angiography.…”

Application of C-arm CBV Measurement for Evaluation before and Immediately after Neuroendovascular Treatment

“…Previous studies reported the clinical application of a C-arm CBV study for the initial diagnosis of acute ischemic stroke. Struffert et al 6) and Fiorella et al 8) compared C-arm CBV images with Computed tomography perfusion (CTP)-CBV images in patients with cerebral infarction. They evaluated the accuracy or specificity of C-arm-CBV-based ischemia detection as satisfactory for the initial diagnosis of ischemic cerebrovascular disorder.…”

“…They evaluated the accuracy or specificity of C-arm-CBV-based ischemia detection as satisfactory for the initial diagnosis of ischemic cerebrovascular disorder. 6,8) Simultaneously, Fiorella et al 8) indicated the importance of keeping a steady state of contrast medium in the brain parenchyma during the acquisition of the fill run. According to their report, when a delayed blood flow was detected in four of five of patients with the quantitative analysis.…”

“…Several studies have reported applications for the initial diagnosis of acute ischemic stroke or an assessment after carotid artery stenting (CAS). [6][7][8][9][10] The C-arm CBV study facilitates the acquisition of real-time information on circulation in the angiography suite. Therefore, utilizing this characteristic, the results of examination before and after thrombectomy or CAS can be compared.…”