低剂量CT扫描在鼻窦检查中的应用价值

Applied Value of Low-dose CT Scanning in Nasal Sinus Examination

目的评价低剂量CT扫描在鼻窦检查中的临床应用价值。方法 100例患者分成少年组(5～15岁)和成年组(16～71岁),各50例,征得其同意在鼻窦常规剂量(150mAs)CT扫描后再行选定层面低剂量单层对照冠状位CT扫描,少年组mAs设为40mAs、25mAs,成年组设为50mAs、30mAs,其他扫描参数不变。由3位CT主治医师采用盲法评价CT图像,分为正常图像、图像有少许伪影、图像有严重伪影等三级对每帧图像进行质量评价。结果少年组和成年组低剂量CT扫描的单次扫描加权CT剂量指数(CTDIw)明显低于常规剂量扫描(P<0.01),少年组40mAs和成年组50mAs剂量扫描所得图像与常规剂量图像质量比较无明显下降,而少年组25mAs和成年组30mAs扫描图像与常规剂量图像质量比较差异有统计学意义。结论分别利用40mAs和50mAs低剂量对青少年和成年人进行鼻窦CT扫描,图像不影响诊断,可以有效降低患者的受辐射剂量。

Objective To assess the value of low dose CT scanning applied in nasal sinus examination. Methods 100 cases were divided into two groups, including youth group and adult group,with 50 cases for each group. After scanned by standard dose（150mAs） , all the patients were scanned with low dose. Those in youth group were scanned with 40mAs and 25mAs, and the others in adult group were scanned with 50mAs and 30mAs. CT images were evaluated by three doctors using blind method. The image quality was evaluated according to 3 grades：normal image,image with mild artifact,and image with serious artifact and the results were analyzed statistically. Results The CTDIw of low - dose CT scanning was obviously lower than that of standard dose （ P 〈 0.01 ）. Compared with the images abtained from standard dose CT scanning,there was no significant difference in the quality of the images abtained from the dose of 40mAs for youth group and 50mAs for adult group,which obvious difference could be found in the images abtained from the dose of 25mAs for youth group and 30mAs for adult group. Conclusion CT scanning with the dose of 40mAs for adolescent and 50mAs for adults in nasal sinus examination Could significantly reduce the patient＇s radiation dose. The images could meet the needs of diagnosis.