Lumbar Spinal Nerve Roots Imaging Using Balanced Sequence with Inversion Recovery (IR) Pulse

Abstract

We devised a method for visualizing the distal portion of lumbar spinal nerve roots in the direction of the long axis using a three-dimensional balanced sequence with inversion recovery pulse, and we established the imaging parameters. This pulse sequence was used with the following parameters: 260 mm field of view, 4.8 ms repetition time, 2.4 ms echo time, 90 degree flip angle, 1.5 mm slice thickness (0.75 mm overlap), and low-high radial k-space profile order. We assessed the signal intensity and contrast for the phantom and healthy volunteer images with different inversion times (TI). Moreover, we evaluated this method by using the optimal TI in clinical cases. The optimal TI obtained from the phantom and human studies was 600 ms. In clinical cases, this method with 600 ms of TI provided the best definition in images of abnormal pathway and compression of the lumbar spinal nerve roots. Our imaging method makes it possible to clearly and noninvasively visualize the lumbar spinal nerve roots.