Development of a Receiver Coil Array for 2D Accelerated Imaging of the Complete Neurovascular System

Introduction Two-dimensional accelerated imaging [1] with acceleration factors as high as R = 8 has been applied successfully in contrastenhanced MR angiography (CE-MRA) of the brain [2, 3] and calves [4]. A key element of this implementation has been the use of multielement receiver coils which are designed for the targeted anatomic region. Multi-element coils for brain MRI are available on commercial MRI systems and can be used for accelerated CE-MRA of the brain vasculature. For example, on the commercial MRI systems at our institution the eight-channel birdcage-like brain coil (8HRBRAIN, Invivo Corporation, Gainesville Fl) can be used for R ≤ 8 2D SENSE brain CE-MRA. However, rather than be limited to the brain, a complete neurovascular exam also includes evaluation of the cervical carotid and vertebral arteries, and the aortic arch and great vessel origins. Another clinically available coil, the neurovascular coil array (NVA), is comprised of eight elements (five in the head region and three about the neck and upper torso). Although this provides expanded coverage to the neck and thorax, the limited number of elements in those areas limits the level of acceleration allowed. Thus, neither the 8HRBRAIN nor the NVA coils nor, to our knowledge, any other coil array allows high 2D acceleration over this extended region. The purpose of this work was to develop a multi-element receiver coil array for neurovascular imaging that has high SNR and the capability for high (R = 4 to 8) 2D SENSE acceleration from the head through the upper torso. Specifically, we hypothesized that a composite array composed of the 8HRBRAIN and an additional modular (8-12 channel) neck/torso array would provide the targeted performance.