Greess H, Wolf H, Baum U, Kalender W A, Bautz W
Institut für Diagnostische Radiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg.
Rofo. 1999 Mar;170(3):246-50. doi: 10.1055/s-2007-1011035.
To examine the feasibility of reducing exposition in CT examinations by applying a prototype device for tube current modulation with the image quality remaining unchanged.
The prototype device for tube current modulation was integrated into a Somatom Plus 4 CT scanner (Siemens). The method is based on anatomy-oriented modulation of the tube current. The attenuation of the X-ray beam by the patient's body was determined online, the tube current was adapted to changing anatomy after a delay of 180 degrees. In ten patients undergoing radiotherapy, four identical scans of the shoulder region were carried out with and without tube current modulation. For determining dose reduction, mAs product of both scans were compared. The evaluation of noise artifacts, low contrast detectability and overall image quality was performed by four radiologists in a blinded fashion.
Patient doses could be reduced by 38% on an average. Scans with tube current modulation were superior to scans without it as to noise (75%), low contrast detectability (51%), artifacts (69%), and overall image quality (71%).
A significant reduction in exposition during CT can be achieved by anatomy-oriented tube current modulation without image degradation.
通过应用一种用于管电流调制的原型设备，在保持图像质量不变的情况下，研究减少CT检查中辐射剂量的可行性。
将管电流调制原型设备集成到一台Somatom Plus 4 CT扫描仪（西门子）中。该方法基于以解剖结构为导向的管电流调制。在线确定患者身体对X射线束的衰减，管电流在经过180度延迟后根据解剖结构的变化进行调整。对10名接受放射治疗的患者，在有和没有管电流调制的情况下对肩部区域进行了4次相同的扫描。为确定剂量减少情况，比较了两次扫描的毫安秒乘积。由4名放射科医生以盲法对噪声伪影、低对比度可探测性和整体图像质量进行评估。
患者剂量平均可降低38%。在噪声（75%）、低对比度可探测性（51%）、伪影（69%）和整体图像质量（71%）方面，有管电流调制的扫描优于无管电流调制的扫描。
通过以解剖结构为导向的管电流调制可显著降低CT检查期间的辐射剂量，且不会导致图像质量下降。
