Brem Matthias H, Zamani Amir A, Riva Roberto, Zou Kelly H, Rumboldt Zoran, Hennig Friedrich F, Kikinis Ron, Norbash Alexander M, Schoepf U Joseph
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Radiology. 2007 Jun;243(3):847-52. doi: 10.1148/radiol.2433050207.
The aim of the study was to retrospectively determine the potential for radiation dose reduction at multidetector computed tomography (CT) of the paranasal sinus by using computer simulation of the effect of low-radiation dose acquisition on diagnostic image quality. This HIPAA compliant study was approved by the institutional human research committee. The need for informed patient consent was waived. Twenty patients underwent four-section CT at 120 kV, 170 mAs, and 4 x 1-mm collimation. Artificial image noise was added to the CT raw data by using a dedicated software platform. Acquisitions with effective tube currents of 134, 100, 67, and 33 mAs were simulated. Each raw data set was reconstructed with bone and soft-tissue algorithms, and two radiologists independently rated the images in blinded fashion. A two-sided paired Student t test was used for statistical analysis. The lowest radiation dose that still provided diagnostic quality was <or=67 effective mAs for osseous structures and <or=134 effective mAs for the optic nerve and the inferior rectus muscle. On the basis of the results, tube currents can be lowered and radiation dose reduced by 20%.
本研究的目的是通过对低辐射剂量采集对鼻窦计算机断层扫描（CT）诊断图像质量影响的计算机模拟，回顾性地确定降低辐射剂量的可能性。这项符合健康保险流通与责任法案（HIPAA）的研究获得了机构人类研究委员会的批准。患者无需签署知情同意书。20例患者接受了四排CT扫描，管电压120 kV，管电流170 mAs，准直4×1 mm。使用专用软件平台向CT原始数据中添加人工图像噪声。模拟了有效管电流分别为134、100、67和33 mAs时的扫描。每组原始数据集均采用骨算法和软组织算法进行重建，两名放射科医生采用盲法独立对图像进行评分。采用双侧配对t检验进行统计分析。对于骨结构，仍能提供诊断质量的最低辐射剂量≤67有效mAs；对于视神经和下直肌，最低辐射剂量≤134有效mAs。根据研究结果，管电流可降低，辐射剂量可减少20%。
