Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
AJR Am J Roentgenol. 2013 Aug;201(2):W297-306. doi: 10.2214/AJR.12.9610.
The purpose of this study is to assess the ability of a novel automatic tube potential selection tool to reduce radiation dose while maintaining diagnostic quality in CT angiography (CTA) and contrast-enhanced abdominopelvic CT.
One hundred one CTA examinations and 90 contrastenhanced abdominopelvic examinations were performed using an automatic tube potential selection tool on a 128-MDCT scanner. Two vascular radiologists and two abdominal radiologists evaluated the image quality for sharpness, noise, artifact, and diagnostic confidence. In a subset of patients who had undergone prior studies (CTA, 28 patients; abdominopelvic CT, 25 patients), a side-by-side comparison was performed by a separate radiologist. Dose reduction and iodine contrast-to-noise ratio resulting from use of the tool were calculated.
For CTA, 80 or 100 kV was selected for 73% of the scans, with a mean dose reduction of 36% relative to the reference 120-kV protocol. For abdominopelvic CT examinations, 80 or 100 kV was used for 55% of the scans, with a mean dose reduction of 25%. Overall dose reduction relative to the reference 120-kV protocol was 25% and 13% for CTA and abdominopelvic CT scans, respectively. Over 98% of scans had acceptable sharpness, noise texture, artifact, and diagnostic confidence for both readers and diagnostic tasks; 94-100% of scans had acceptable noise. Iodine contrast-to-noise ratio was significantly higher than (p < 0.001) or similar to (p = 0.11) that of prior scans, and equivalent quality was achieved despite the dose reduction.
Automatic tube potential selection provides an efficient and quantitativeway to guide the selection of the optimal tube potential for CTA and abdominopelvic CT examinations.
本研究旨在评估一种新型自动管电压选择工具在 CT 血管造影（CTA）和增强腹部盆腔 CT 中降低辐射剂量同时保持诊断质量的能力。
在一台 128 层 MDCT 扫描仪上，使用自动管电压选择工具对 101 例 CTA 检查和 90 例增强腹部盆腔 CT 检查进行了检查。两位血管放射科医生和两位腹部放射科医生评估了图像质量的清晰度、噪声、伪影和诊断信心。在一组曾进行过先前研究（CTA，28 例；腹部盆腔 CT，25 例）的患者中，由另一位放射科医生进行了并排比较。计算了使用该工具所导致的剂量降低和碘对比噪声比。
对于 CTA，73%的扫描选择了 80 或 100 kV，与参考 120-kV 方案相比，平均剂量降低了 36%。对于腹部盆腔 CT 检查，55%的扫描使用了 80 或 100 kV，平均剂量降低了 25%。相对于参考 120-kV 方案，CTA 和腹部盆腔 CT 扫描的总剂量降低分别为 25%和 13%。两位读者和诊断任务都有超过 98%的扫描具有可接受的清晰度、噪声纹理、伪影和诊断信心；94-100%的扫描具有可接受的噪声。碘对比噪声比显著高于（p<0.001）或与（p=0.11）先前扫描相似，并且尽管降低了剂量仍达到了等效质量。
自动管电压选择为 CTA 和增强腹部盆腔 CT 检查提供了一种有效和定量的指导最佳管电压选择的方法。
