ABSTRACT
Objective To explore the diagnostic performance of 64-slice spiral CT combined with exercise treadmill test for coronary artery disease ( CAD). Methods Eighty-six patients suspected of CAD were divided into low risk group, intermediate risk group and high risk group according to estimated pretest probabilities of CAD. All patients underwent coronary angiography, 64-slice spiral CT and exercise treadmill test. With coronary artery stenosis rate >50% as positive findings, the sensitivity, specificity, positive predictive value ( PPV), negative predictive value ( NPV) and accuracy of 64-slice spiral CT and 64-slice spiral CT combined with exercise treadmill test in diagnosis of CAD were calculated. Results With coronary angiography as the "golden criteria", the sensitivity, specificity, PPV, NPV and accuracy of 64-slice spiral CT in diagnosis of CAD were 95.2% , 88.6% , 88.9% , 95.1% and 91.9% , respectively. The sensitivity of low risk group, intermediate risk group and high risk group was 100% , 100% and 92.6%, specificity was 94.4% , 94.1% and 66.7%, PPV was 80.0%, 91.7% and 89.3%, NPV was 100% , 100% and 75.0%, and accuracy was 95.5% , 96.4% and 86.1%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of 64-slice spiral CT combined with exercise treadmill test in diagnosis of CAD were 97.6%, 97.7%, 97.6%, 97.7% and 97.7%, respectively. Conclusion 64-slice spiral CT combined with exercise treadmill test works well in screening CAD, especially for those with a low or intermediate estimated pretest probability.
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.