Measurement of Cerebral Blood Volume using Angiographic C-Arm Systems

While perfusion imaging is a well established diagnostic imaging technique, until now, it could not be performed using angiographic equipment. The ability to assess information about tissue perfusion in the angiographic suite should help to optimize management of patients with neurovascular diseases. We present a technique to measure cerebral blood volume (CBV) for the entire brain using an angiographic C-arm system. Combining a rotational acquisition protocol similar to that used for standard three-dimensional rotational angiography (3D DSA) in conjunction with a modified injection protocol providing a steady state of tissue contrast during the acquisition the data necessary to calculate CBV is acquired. The three-dimensional (3D) CBV maps are generated using a special reconstruction scheme which includes the automated detection of an arterial input function and several correction steps. For evaluation we compared this technique with standard perfusion CT (PCT) measurements in five healthy canines. Qualitative comparison of the CBV maps as well as quantitative comparison using 12 ROIs for each map showed a good correlation between the new technique and traditional PCT. In addition we evaluated the technique in a stroke model in canines. The presented technique provides the first step toward providing information about tissue perfusion available during the treatment of neurovascular diseases in the angiographic suite.