Optimization of the number of selectable channels for spine phased array coils for transverse imaging

Purpose The aim of this study was to investigate whether the signal-to-noise ratio (SNR) in transverse images acquired from spine phased array coils is improved by deactivating coils distant from the imaging region and to identify the optimum coil settings. Materials and methods Ten healthy volunteers (five men, five women; average age 38 years) underwent transverse magnetic resonance imaging (MRI) of the cervical spine using four to one channels of a four-channel phased array coil for cervical imaging. The SNR of cerebrospinal fluid (CSF), spinal cord, muscle tissue, intervertebral disc, vertebral body, and prevertebral soft tissue was measured for each coil combination. Results In all measured regions, the SNR was the highest for images acquired using two coils; the SNR was significantly higher for two coils than for four coils in CSF, spinal cord, muscle tissue, intervertebral disc, vertebral body, and prevertebral soft tissue ( P < 0.001, P = 0.019, P < 0.0001, P = 0.014, P = 0.010, P < 0.001). Conclusion Deactivating two of the four coils used for sagittal sections, meaning that two coils are active, resulted in improved SNR for transverse images. Selecting the optimum number and combination of coils for each imaging cross section may enable acquisition of images with a better SNR.