van Straten M, Venema H W, Majoie C B L M, Freling N J M, Grimbergen C A, den Heeten G J
Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
AJNR Am J Neuroradiol. 2007 Mar;28(3):421-7.
Routine CT of the brain is traditionally performed with sequential CT. We assessed whether sequential CT can be replaced with thinly collimated multisection spiral CT without loss of image quality.
An observer study was conducted using data from 23 patients who were scanned with both a sequential (collimation, 4 x 5 mm) and a spiral technique (collimation, 4 x 1 mm; pitch, 0.875). Each sequential image was registered with 4 combined spiral CT images at 1.2 mm distance. Two neuroradiologists blindly scored 232 image pairs on 6 aspects: streak artifacts, visualization of brain tissue near skull, visualization of hypoattenuated lesions, gray/white matter differentiation, image noise, and overall image quality. A 5-point scale (range, -2 to 2) was used to score the preferences. The 23 pairs of complete scans were scored likewise. In this case, no registration was performed.
Virtually all mean scores were positive (ie, showed a preference for the spiral technique). For the comparison of image pairs, the preferences with respect to streak artifacts (mean score, 1.36), visualization of brain tissue near the skull (mean score, 0.69), and overall image quality (mean score, 0.95) were significant (P < .001). With respect to visualization of hypo-attenuated lesions, image noise, and gray/white matter differentiation (mean scores, 0.18, 0.27, and 0.13), the preferences for spiral CT were not significant. The preferences for the spiral technique were also present at the comparison of the complete scans.
Thinly collimated multisection spiral CT of the brain with image combining is superior to thickly collimated sequential CT.
传统上，脑部常规CT采用序列CT进行扫描。我们评估了在不损失图像质量的情况下，序列CT是否可被薄层准直多层螺旋CT所取代。
采用23例患者的数据进行观察者研究，这些患者同时接受了序列扫描（准直，4×5mm）和螺旋扫描技术（准直，4×1mm；螺距，0.875）。将每幅序列图像与距离为1.2mm的4幅组合螺旋CT图像进行配准。两名神经放射科医生对232对图像在6个方面进行盲法评分：条纹伪影、颅骨附近脑组织的显示、低密度病变的显示、灰质/白质区分、图像噪声和整体图像质量。采用5分制（范围，-2至2）对偏好程度进行评分。对23对完整扫描图像同样进行评分。在这种情况下，不进行配准。
几乎所有的平均评分均为正值（即显示出对螺旋扫描技术的偏好）。对于图像对的比较，在条纹伪影（平均评分，1.36）、颅骨附近脑组织的显示（平均评分，0.69）和整体图像质量（平均评分，0.95）方面的偏好具有统计学意义（P <.001）。在低密度病变的显示、图像噪声和灰质/白质区分（平均评分，0.18、0.27和0.13）方面，对螺旋CT的偏好无统计学意义。在完整扫描图像的比较中也存在对螺旋扫描技术的偏好。
采用图像合并技术的脑部薄层准直多层螺旋CT优于厚层准直序列CT。
