Thick-Slice Magnetic Resonance Myelography in Spine Imaging: A Clinico-Radiological Study in Tertiary Care Center

Two-Dimensional Single Thick-Slice Magnetic Resonance Myelography

Abstract

Background: Single-slice or multisclice both the techniques can be used to obtain MRM. The key difference between the two techniques is  the time required; single-slice technique using thick-slab take less time, while multi-slice techniques require more time. The single-slice MRM technique, excellently suppresses the background signals (from fat or paravertebral veins) and it also significantly reduces the CSF flow artefacts. As a result, the aim of this study was to assess the effectiveness of routinely using single thick-slice 2-D MRM to provide further details in the spinal and extra-spinal regions. Subjects and Methods: TR (repetition time)/TE (echo time) used were infinite/1200-1400; ETL (echo-train length), 256; one signal averaged, and imaging period of 2.8 seconds were the imaging parameters for the cervico-thoracic spine. To completely eliminate the fat signal in the lumbar spine an inversion pulse was used. The parameters were TR/TE was infinite/1200-1600; inversion time was 150; ETL was 256; four signals averaged; and imaging period was 32 seconds. For the cervicothoracic the spatial resolution was 0.98x 0.98 mm (pixel size) and lumbar spines, it was 0.55x 0.55 mm. the slice thickness of 40-60 mm was used and for each patient three images were obtained in coronal and bilateral oblique coronal directions. Midsagittal T2-weighted MR images were used to view single-slice MR myelographic images, which allowed for better anatomic resolution. A 1.5-T unit was used for all MR imaging (Philips Achieva Medical Systems). While 180 patients underwent single thick slice two Dimensional MRM using T2 half Fourier acquisition SSTE (single shot turbo spin echo) method in addition to routine MR procedure for the spine. The evaluation of the images was done in the spinal and extra-spinal areas, for additional diagnostic details. The effectiveness of MRM in identifying spinal or extra spinal findings was graded using a three-point grading system. Grade 1 suggested that MRM made no contribution, whereas grade 3 indicated that it was valuable in positively identifying the findings. Results: MRMs spine utility was classified as grade 3 in 11% of cases (20/180), grade 2 in 21.7 percent of cases (39/180), and grade 1 in 67.3 percent of cases (121/180). As a result, the MRM in the spine was advantageous in 32.5 percent of cases (59/180). Additional spinal pathologies were found in 15.2 percent  of cases (27/180). Conclusion: Thus we conclude that, when used in combination with routine MR sequences, 2D single thick slice MRM can provide more benefits in spinal imaging.