Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Tuebingen, Germany.
Invest Radiol. 2012 Feb;47(2):148-52. doi: 10.1097/RLI.0b013e3182311504.
To evaluate radiation exposure and image quality in thoracic computed tomography (CT) using a new dose-saving algorithm to protect radiosensitive organs.
For dose measurements, an Alderson RANDO phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to the International Commission on Radiologic Protection 103. Exposure was performed on a second-generation dual-source CT. The following parameters for thoracic CT were used: 160 effective mAs, 120 kV, scan range of 30 cm, collimation of 128 × 0.6 mm. For the acquisition, the tube current modulation type XCare was used, which reduces the tube current for anterior tube position to minimize direct exposure to anterior located organs. To compare differences, scans with and without XCare were performed. Objective signal-to-noise measurements were evaluated, and the subjective noise perception was rated in a 3-point scale (1: excellent, 3: affecting diagnostic accuracy) in 30 patients with a standard thoracic examination and a follow-up using XCare.
A substantial dose reduction in radiosensitive tissues was evident using the dose-saving algorithm XCare. Specifically, reductions of 35.2% for the female breast and 20.1% for the thyroid gland were measured, resulting in a decreasing effective whole-body dose of 8.0% and 14.3% for males and females, respectively. The objective and subjective evaluation of image quality showed no significant differences between both scan protocols (P > 0.05). Mean signal-to-noise ratio was 1.3 ± 0.2 and 1.2 ± 0.2 in scan protocols without and with XCare, respectively. The subjective scores at the level of the pulmonary trunk were 1.2 ± 0.4 and 1.4 ± 0.5 in standard chest scan and scans with the dose-saving algorithm XCare, respectively.
The XCare technique protects radiosensitive organs like the female breast and the thyroid gland without affecting image quality. Therefore, this dose-saving algorithm may be used in thoracic CT examinations in male and female patients.
评估使用新的剂量节省算法保护敏感器官的胸部计算机断层扫描（CT）的辐射暴露和图像质量。
为了进行剂量测量，使用配备有热释光剂量计的 Alderson RANDO 体模。根据国际辐射防护委员会 103 号报告计算有效剂量。在第二代双源 CT 上进行曝光。胸部 CT 的以下参数用于：160 有效毫安秒，120 kV，扫描范围 30 cm，准直 128×0.6 mm。对于采集，使用管电流调制型 XCare，该技术降低前管位置的管电流以最大程度减少对位于前部的器官的直接暴露。为了进行比较，进行了有和没有 XCare 的扫描。评估了客观的信噪比测量，并在 30 名接受标准胸部检查的患者中使用 XCare 进行后续检查，使用 3 分制（1：优秀，3：影响诊断准确性）对噪声感知进行主观评估。
使用剂量节省算法 XCare，明显降低了对敏感器官的剂量。具体而言，女性乳房的剂量降低了 35.2%，甲状腺的剂量降低了 20.1%，导致男性和女性的有效全身剂量分别降低了 8.0%和 14.3%。两种扫描方案的客观和主观图像质量评估均未显示出显著差异（P>0.05）。无 XCare 和有 XCare 的扫描方案的平均信噪比分别为 1.3±0.2 和 1.2±0.2。在标准胸部扫描和具有剂量节省算法 XCare 的扫描中，肺动脉水平的主观评分分别为 1.2±0.4 和 1.4±0.5。
XCare 技术可保护女性乳房和甲状腺等敏感器官，而不会影响图像质量。因此，该剂量节省算法可用于男性和女性患者的胸部 CT 检查。
