Hohl Christian, Suess Christoph, Wildberger Joachim E, Honnef Dagmar, Das Marco, Mühlenbruch Georg, Schaller Andreas, Günther Rolf W, Mahnken Andreas H
Department of Diagnostic Radiology, University of Technology of Aachen, Pauwelsstrasse 30, D-52057 Aachen, Germany.
Radiology. 2008 Feb;246(2):519-25. doi: 10.1148/radiol.2462061968.
To prospectively evaluate, in a phantom, the dose reductions achievable by using angular beam modulation (ABM) during computed tomographic (CT) fluoroscopy-guided thoracic interventions.
To enable measurement of organ doses and effective patient dose, a female Alderson-Rando phantom was equipped with thermoluminescent dosimeters (TLDs) in 41 positions, with three TLDs in each position. Additionally, the local dose was assessed in 22 locations above the phantom to estimate the radiation exposure to the radiologist's hand and the patient's skin dose during thoracic interventions. Radiation exposure was performed with a 64-section multidetector CT scanner in the CT fluoroscopy mode, simulating a CT fluoroscopy-guided chest intervention. Effective dose, breast dose, and the dose to the radiologist's hand during the simulated chest intervention were measured with and without ABM. Image noise as an indicator for image quality was compared for both settings. Statistical significance of the measured dose reductions and the image noise was tested by using the paired-samples t test, with P < .05 indicating a significant difference.
ABM significantly reduced the effective patient dose by 35%, the skin dose by 75%, the breast dose by 47% (P < .001 for all), and the physician's hand dose by between 27% (scattered radiation, P = .007) and 72% (direct radiation, P < .001). No significant difference was found in a comparison of the image noise with and that without ABM.
ABM leads to significant dose reductions for both patients and personnel during CT fluoroscopy-guided thoracic interventions, without impairing image quality.
前瞻性地评估在计算机断层扫描（CT）透视引导下的胸部介入操作中，使用角度束调制（ABM）可实现的剂量降低情况。
为了能够测量器官剂量和有效患者剂量，在女性Alderson-Rando体模的41个位置配备了热释光剂量计（TLD），每个位置有三个TLD。此外，在体模上方的22个位置评估局部剂量，以估计胸部介入操作期间放射科医生手部的辐射暴露和患者的皮肤剂量。使用64排多层螺旋CT扫描仪在CT透视模式下进行辐射暴露，模拟CT透视引导下的胸部介入操作。在有和没有ABM的情况下，测量模拟胸部介入操作期间的有效剂量、乳腺剂量和放射科医生手部的剂量。比较两种设置下作为图像质量指标的图像噪声。使用配对样本t检验对测量的剂量降低和图像噪声的统计学显著性进行检验，P <.05表示有显著差异。
ABM显著降低了有效患者剂量35%，皮肤剂量75%，乳腺剂量47%（所有P <.001）以及医生手部剂量27%（散射辐射，P =.007）至72%（直接辐射，P <.001）。在有和没有ABM的情况下比较图像噪声，未发现显著差异。
在CT透视引导下的胸部介入操作中ABM可显著降低患者和工作人员的剂量，且不影响图像质量。
