头颅CT不同扫描方式的图像质量分析

Image Quality Assessment of Brain CT with Different Scanning Modes

目的分析256排宽体探测器轴扫描、常规探测器轴扫描和螺旋扫描头颅CT的图像质量,为患者提供更加有效的头颅CT检查方法。资料与方法将90例行常规头颅CT检查的患者随机分为3组进行前瞻性研究,采用GE Revolution CT分别进行探测器宽度160 mm轴扫描、40 mm轴扫描和40 mm螺旋扫描。调整扫描条件使辐射剂量保持一致的情况下进行图像质量分析。比较3种扫描模式所得图像的脑灰、白质CT值及灰白质对比噪声比(CNR)和图像噪声,并对3种扫描方式进行图像质量的主观评分。结果侧脑室体部层面3种扫描方式的脑灰、白质CT值及CNR差异无统计学意义(P>0.05)。在半卵圆中心层面,160 mm轴扫描的脑灰、白质CT值分别为(31.71±1.82)HU和(22.97±1.50)HU,灰白质CNR为2.05±0.42,与其他2种扫描方式差异有统计学意义(F=26.74、47.16、3.85,P<0.05)。在半卵圆中心层面,160 mm轴扫描的图像噪声低于其他2种扫描方式,差异有统计学意义(F=6.31,P<0.05);在基底节层面和后颅窝层面3种扫描方式的图像噪声差异无统计学意义(P>0.05)。3种扫描方式主观评分均符合诊断标准,差异无统计学意义(P>0.05)。160 mm宽体探测器轴扫描有效剂量、扫描时间均低于其他2种扫描方式,射线利用率高。结论 160 mm宽体探测器头颅CT轴扫描更加适合常规头颅CT检查,并可作为急诊及不合作患者的首选扫描方式。

Purpose To analyze the image quality of brain CT with 256-slice wide detector axial scanning mode, routine axial scanning mode and spiral scanning mode, and to provide a more effective brain CT examination method for patients. Materials and Methods The prospective study was conducted on 90 patients accepting routine brain CT examination, and they were randomly divided into three groups. CT examination with 160 mm axial scanning mode, 40 mm axial scanning mode and 40 mm spiral scanning mode were respectively conducted using GE Revolution CT. The scanning condition was adjusted to remain constant radiation dose, and then the image quality was analyzed. CT attenuation of gray and white matter, contrast-to-noise ratio（CNR） of white-gray matter and image noise of the three scanning modes were compared. Subjective scoring on image quality of the three scanning modes was also performed. Results On body lateral cerebral ventricle level, there were no signifi cant difference in CT attenuation of gray and white matter and CNR（P〈0.05）. On centrum semiovale level, the CT attenuation of gray matter [（31.71±1.82） HU], white matter [（22.97±1.50） HU] and CNR 2.05±0.42 of 160 mm axial scanning mode was significantly different from the other two scanning modes（F=26.74, 47.16 and 3.85, P〈0.05）. On centrum semiovale level, image noise of 160 mm axial scanning mode was lower than the other two kinds of scanning methods（F=6.31, P〈0.05）, in the basal ganglia and posterior fossa there were no statistically significant differences in the image noise between the three scanning modes（P〈0.05）. The subjective score of the three scanning modes all met the diagnostic requirements, and there was no significant difference（P〈0.05）. The effective dose and scanning time of 160 mm axial scanning mode was lower than those of the other two scanning modes, and the X-ray utilization was higher. Conclusion 160 mm wide detector axial scanning mode is more suitable for brain CT scan, and it can be used as the preferred scanning mode in the emergency and among non-cooperative patients.