成人踝、腕关节低剂量螺旋CT扫描方法研究

发布时间：2018-04-22 12:18

本文选题：关节 + CT　；参考：《吉林大学》2013年硕士论文

【摘要】：目的：在256层螺旋CT上设置不同管电流、电压条件扫描，比较在不同剂量条件下所得的图像质量，以评价踝腕关节低剂量扫描对关节正常结构显示及其图像质量的影响，从而探讨256层螺旋CT踝腕关节低剂量扫描的可行性及其临床价值。方法：收集在2012年9月到2013年9月在某市三甲级某医院进行CT检查的成年人患者106人（130腕、踝）的相关材料，调查排除可能的骨质密度异常人员（长期酗酒、3个月内曾经大量应用激素、绝经后女性、糖尿病病史、70岁以上老年人等）。患者分为实验组、对照组。各组受检者年龄、性别无显著差异。采用PHILIPS256层iCT螺旋CT进行成像扫描。由于踝、腕关节骨结构及软组织结构的厚度及密度相似，故使用相同扫描参数：扫描野250mm，扫描长度150mm，层厚1.4mm，矩阵768×768，常规剂量条件120kV/240mAs（对照组，30例），低剂量条件组（实验组）100kV/100mA（s30例）、100kV/80mAs（30例）、100kV/60mAs（30例）、80kV/60mAs（10例）。扫描剂量由螺旋CT扫描窗中给出的CT剂量指数（CTDIvol）、剂量长度乘积（DLP）给出（经过机器自带水模测量并校正）。后处理工作站为IntelliSpace Portal V4.0.1。对所得原始数据进行重建处理后，以同层面感兴趣区测得CT值，计算标准差（SD）记为客观评分，由两位放射科专家以双盲的方式对各扫描剂量条件下所得图像进行主观评分，用统计软件对所得分数进行数据分析。结果：其中80kV/60mAs组，主观评分2.65±0.53，噪声为43.83±7.17，实验中图像满意度较差，采集10例样本后放弃。当扫描条件为120kV/240mAs、100kV/100mAs、100kV/80mAs、100kV/60mAs、80kV/60mAs时，DLP分别为235.74±17.34、43.94±6.33、40.88±4.17、26.48±3.41、18.19±1.72，主观评分为3.97±0.16，3.58±0.51，3.29±0.46，3.06±0.27，2.65±0.53，客观评分（噪声）分别为7.76±1.68、10.18±3.97、23.03±4.17、34.88±6.27、43.83±7.17。各实验组较各对照组、各实验组组间主客观评分有显著差异（P＜0.05）。100kV/100mAs、100kV/80mAs、100kV/60mAs较对照组图像，在骨质、软组织、伪影及噪声、三维重建方面等主观分略有下降，但是得分均值在3分以上，其中100kV/100mAs、100kV/60mAs各有一例三维重建图像内部细节显示欠清；客观评分SD值升高。结论：与常规扫描条件120kV/240mAs下的图像相比，当扫描条件降至80kV/60mAs，患者剂量降至18.19±1.72mGy·cm，图像质量主观评分2.65±0.53，已不足以满足诊断需要。当扫描条件降至100kV/60mAs，，患者剂量降至26.48±3.41mGy·cm，主观评分为3.06±0.27， CT三维图像质量大多处于良好级水平，优级图像比例降低，但低剂量下的横断及三维图像能够较好显示解剖关系，能准确显示踝、腕关节创伤空间信息，符合临床需要，并保护了患者。
[Abstract]:Objective: to compare the image quality of 256-slice spiral CT with different current and voltage conditions, and to evaluate the effect of low-dose scan on the normal structure and image quality of ankle and wrist joint. To explore the feasibility and clinical value of 256-slice spiral CT low-dose scan of ankle and wrist joint. Methods: the data of 130 wrists and ankles of 106 adult patients who underwent CT examination in a hospital of Grade A in a city from September 2012 to September 2013 were collected. The study ruled out possible bone density abnormalities (chronic alcoholism, heavy use of hormones within 3 months, postmenopausal women, diabetic history and older persons over 70 years of age). The patients were divided into experimental group and control group. There was no significant difference in age and sex among the three groups. PHILIPS256 slice iCT spiral CT was used to scan. Because of the similar thickness and density of ankle and wrist bone structure and soft tissue structure, Therefore, the same scanning parameters were used: scanning field 250 mm, scanning length 150 mm, slice thickness 1.4 mm, matrix 768 脳 768, routine dose condition 120 kV / 24 0 mAs( control group, 30 cases, control group, 100 kV / 100 mAgs, 30 cases, 100 kV / 80 mASC, 30 cases, 100 kV / 60 MV / 60 mAsC, n = 10, n = 10). The scanning dose is given by the CT dose index (CTDIvoll) given in the spiral CT scanning window, the dose length product (DLP) (measured and corrected by the water model of the machine). The post processing workstation is IntelliSpace Portal V4.0.1. After the original data were reconstructed, the CT values were measured in the same area of interest, and the standard deviation was calculated as an objective score. The images were scored subjectively by two radiologists in a double-blind manner. The data of the score were analyzed by statistical software. Results: in the 80kV/60mAs group, the subjective score was 2.65 卤0.53 and the noise was 43.83 卤7.17.The image satisfaction was poor in the experiment, and 10 samples were collected and abandoned. When the scanning condition was 120kV / 240mAsL / 100kV / 100mAsL / 100kV / 80mAsL / 80kV / 80kV / 60mAS-80kV / 60mAs, respectively, the DLP was 235.74 卤17.34nb 43.94 卤6.33ng 40.88 卤4.1736.48 卤3.4118.19 卤1.72, subjective score was 3.97 卤0.16h3.58 卤0.513.29 卤0.276kV 3.06 卤0.272.65 卤0.53, objective score (noise) was 7.76 卤1.6810.18 卤3.9710.18 卤3.974.88 卤6.2734.88 卤6.2734.88 卤7.173.83 卤7.17173.83 respectively. The subjective and objective scores of each experimental group were significantly different from those of the control group (P < 0.05) .100kV / 100mAs-100kV / / 80mAs-100kV / 60mAs were slightly lower than those of the control group in terms of bone, soft tissue, artifact, noise, 3D reconstruction, and so on, but the average score was more than 3 points. Among them, 100kV / 100kV / 100kV / 60mAs each had an incomplete internal detail of 3D reconstruction image, and the objective score of SD was increased. Conclusion: when the scanning condition is reduced to 80 kV / 60 mAs, the patient dose decreases to 18.19 卤1.72mGy cm and the subjective score of image quality is 2.65 卤0.53, which is not enough to meet the need of diagnosis. When the scanning condition was reduced to 100 kV / 60 mAs, the patient dose was reduced to 26.48 卤3.41mGy cm, and the subjective score was 3.06 卤0.27. The quality of 3D CT images was mostly at a good level, and the proportion of superior images decreased, but the cross-sectional and three-dimensional images at low dose could better display the anatomic relationship. Can accurately display ankle, wrist joint trauma space information, meet the clinical needs, and protect the patient.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R816.8

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