64层螺旋CT低剂量扫描诊断外伤性肋骨骨折

目的：探讨64层螺旋CT低剂量扫描诊断外伤性肋骨骨折的价值。方法：随机选择临床疑诊外伤性骨折患者68例,知情同意后分别行胸部CT常规剂量和低剂量扫描,图像行0.625mm薄层重建与曲面重建,由两组医师采用双盲法对图像质量及骨折情况进行分析统计,评价低剂量扫描对于肋骨骨折的诊断价值;同时对两组的CT检查辐射剂量进行对照研究。结果：常规剂量与低剂量扫描方法分别诊断肋骨骨折286处和281处,其诊断符合率为98.25%。两组扫描模式对肋骨显示的图像质量差异无统计学意义（P〉0.05）。常规剂量扫描模式的加权容积CT剂量指数（CTDIvol）为（13.46±1.13）mGy,低剂量扫描模式CTDIvol为（5.42±0.76）mGy,低剂量扫描模式较常规剂量扫描模式的CTDIvol值下降了59.7%。结论：64层螺旋CT低剂量扫描模式可用于外伤性肋骨骨折的临床诊断,具有与常规剂量扫描同等的诊断价值。

Value of Low Dose Scan Mode with 64-slice CT in the Diagnosis of Traumatic Rib Fracture

Objective： To explore the value of low dose scan mode with 64 slice CT in the diagnosis of traumatic rib fracture. Methods：After their consent as being volunteers of the study, both conventional and low dose CT examinations were performed in 68 randomized patients who were diagnosed with possible traumatic rib fracture clinically. Multi-planar reformation （MPR） and curved-planar reformation （CPR） were done based on 0. 625mm thin-slice images. Image quality evaluation and fracture diagnosis were made by two groups of experienced radiologists double-blindly, radiation doses of the two scan modes were compared. Results： Among 68 patients, 286 and 281 traumatic rib fractures were diagnosed on conventional and low dose scan images separately, the diagnosis accordance rate was 98.25 %. There was no statistical difference between the two scan modes used for rib fracture diagnostic purpose （P〈0.05）. weighted volume computed tomography dose index （CTDIvol） of conventional modality was （13.46 ± 1. 13）mGy, and that of the low dose modality was （5.42 ± 0.76）mGy. Radiation dose reduction of low dose scan mode was 59.70%. Conclusion： Low dose scan mode of 64 slice CT is as valuable as conventional scan mode in the diagnosis of traumatic rib fracture and so can be practically applied clinically.