Pace Ivana, Zarb Francis
Radiol Technol. 2015 Mar-Apr;86(4):373-8.
To evaluate and compare image quality and radiation dose of sequential computed tomography (CT) examinations of the brain and spiral CT examinations of the brain imaged on a GE HiSpeed NX/I Dual Slice 2CT scanner.
A random sample of 40 patients referred for CT examination of the brain was selected and divided into 2 groups. Half of the patients were scanned using the sequential technique; the other half were scanned using the spiral technique. Radiation dose data—both the computed tomography dose index (CTDI) and the dose length product (DLP)—were recorded on a checklist at the end of each examination. Using the European Guidelines on Quality Criteria for Computed Tomography, 4 radiologists conducted a visual grading analysis and rated the level of visibility of 6 anatomical structures considered necessary to produce images of high quality.
The mean CTDI(vol) and DLP values were statistically significantly higher (P <.05) with the sequential scans (CTDI(vol): 22.06 mGy; DLP: 304.60 mGy • cm) than with the spiral scans (CTDI(vol): 14.94 mGy; DLP: 229.10 mGy • cm). The mean image quality rating scores for all criteria of the sequential scanning technique were statistically significantly higher (P <.05) in the visual grading analysis than those of the spiral scanning technique.
In this local study, the sequential technique was preferred over the spiral technique for both overall image quality and differentiation between gray and white matter in brain CT scans. Other similar studies counter this finding.
The radiation dose seen with the sequential CT scanning technique was significantly higher than that seen with the spiral CT scanning technique. However, image quality with the sequential technique was statistically significantly superior (P <.05).
在GE HiSpeed NX/I双排螺旋CT扫描仪上，评估并比较脑部序列计算机断层扫描（CT）检查与脑部螺旋CT检查的图像质量和辐射剂量。
随机选取40例因脑部CT检查而就诊的患者，分为两组。一半患者采用序列扫描技术进行扫描；另一半采用螺旋扫描技术进行扫描。每次检查结束时，在检查表上记录辐射剂量数据，即计算机断层扫描剂量指数（CTDI）和剂量长度乘积（DLP）。4名放射科医生依据欧洲计算机断层扫描质量标准指南，进行视觉分级分析，并对生成高质量图像所需的6个解剖结构的可见度水平进行评分。
序列扫描的平均CTDI(vol)和DLP值（CTDI(vol)：22.06 mGy；DLP：304.60 mGy•cm）在统计学上显著高于螺旋扫描（CTDI(vol)：14.94 mGy；DLP：229.10 mGy•cm）（P<.05）。在视觉分级分析中，序列扫描技术所有标准的平均图像质量评分在统计学上显著高于螺旋扫描技术（P<.05）。
在本局部研究中，对于脑部CT扫描的整体图像质量以及灰质和白质的区分，序列扫描技术优于螺旋扫描技术。其他类似研究则与这一结果相反。
序列CT扫描技术的辐射剂量显著高于螺旋CT扫描技术。然而，序列扫描技术的图像质量在统计学上显著更优（P<.05）。
