Feasibility study of perfusion imaging using flat detector CT with an intra-arterial injection protocol compared to conventional multi-slice perfusion CT with an intravenous injection protocol.

This study investigated the feasibility of using intra-arterial injection-based cerebral blood volume (CBV) imaging with flat detector computed tomography (CT, IAFD-CBV). It is proven that this new method could provide comparable physiologic information as standard intravenous injection-based multi-slice computed tomography CBV imaging (IVCT-CBV). Twelve patients were examined using both IAFD-CBV and IVCT-CBV. An experienced neuroradiologist read both sets of generated CBV maps. If a physiologic perfusion disorder was detected in standard IVCT-CBV, the focus was to check whether IAFD-CBV indicated the same disorder or not. Otherwise, if no disorder was detected, relative CBV (rCBV) values at different basal ganglia regions were measured for both CBV maps and then compared. For three patients with lesions, IAFD-CBV and IVCT-CBV showed similar perfusion disorders in the corresponding regions. For nine patients without lesions, both CBV maps showed good symmetry of contrast agent (CA) distribution for left/right hemisphere, the total average of rCBV was found to be 0.94 -/+0.18 and 1.01 -/+0.14 (1.0 for perfect symmetry) in IAFD-CBV and IVCT-CBV, respectively. However, compared to IVCT-CBV, IAFD-CBV imaging required 70% less contrast agent (CA). In general, a good correlation between IAFD-CBV and IVCT-CBV was found for all 12 patients. Minor deviations of IAFD-CBV were only detected at regions supplied by the middle cerebral artery. IAFD-CBV imaging, which can be directly performed in a catheterization laboratory, was proven to be technically feasible for real-time CBV assessment of the whole brain with good accuracy, and minimized CA usage.