Clinical application of multi-slice helical CT volumetric scanning in lumber spine / 中华放射学杂志

ABSTRACT

Objective To evaluate the clinical application value of multi-slice helical CT volumetric (VH) scanning in lumber spine. Methods One thousand of patients with back and leg pain who underwent CT examinations were selected as subjects. We simulated the traditional protocol of single-slice(SS) discrete scanning for L3/4, L4/5, and LS/S1 intervertebral discs. The VH scanning mode was performed with 120 kV, 210 mAs,pitch of 1.5 and coverage of 97. 5 mm. The simulated SS scanning mode was performed with 120 kV, 240 mAs and coverage of 45.0 mm. The diagnostic outcomes and the radiation doses were compared between the two scanning modes. Two groups doctors observed ten terms, including the osseous spinal stenosis,narrowed intervertebral space and so on in two scanning modes respectively. Then consistency analysis of the data was carried out. Results The VH scanning mode showed far more features than the SS mode. The detection rates of the VH mode in the osseous spinal stenosis, narrowed intervertebral space,herniated nucleus pulposus, narrowed lateral recess, vertebral lesion, hypertrophy of L5 transverse process,abnormal direction of facet, facet degeneration, lumbar spondyloschisis, and paraspinal soft tissue were 11.8% (n =118), 38. 5% (n =385), 9. 3% (n =93), 46. 8% (n =468), 31.4% (n =314), 5.7% (n =57), 25.4% (n = 254), 49. 7% (n = 497), 9.9% (n = 99), and 0. 6% (n = 6) respectively, while the detection rates of the SS mode in ten terms were 5.6% (n = 56), 0, 0. 6% (n = 6), 27. 9% (n = 279),22.4% (n =224), 1.2% (n = 12), 16.7% (n = 167), 37.2% (n =372), 0.5% (n =5), and 0.2%(n = 2) respectively. The difference between the two groups had statistically significance (average P <0.05), except the paraspinal soft tissue abnormal (P > 0.05). The detection rates of the VH mode were higher than the SS mode in the osseous spinal stenosis, narrowed intervertebral space, herniated nucleus pulposus, lumbar spondyloschisis, being 6.2% (n = 62) , 38. 5% (n = 385) , 8.7% (n = 87), and 9.4%(n =94), respectively. In addition, VH mode only partially showed the articular facets, narrowed lateral recess, hypertrophy of L.5 transverse process, and paraspinal soft tissue. We could not acquire the imaging slices paralleling to intervertebral discs in SS mode in 467 patients (46.7%) with lumbosacral angle greater than 35°. The radiation dose of VH mode (164.9 mGy/em) was slightly higher than SS mode (147.0 mGy/cm) Conclusion MSCT VH scanning mode can significantly improve the diagnostic rate of lumbar spine diseases compared with SS mode, and was not restricted by the lumbosacral angle with slightly increasing radiation dosage.