Department of Radiology, Duke University Medical Center, Erwin Rd, Durham, NC 27710, USA.
Radiology. 2010 Aug;256(2):450-9. doi: 10.1148/radiol.10091819.
To intraindividually compare a low-tube-voltage (80 kVp), high-tube-current (675 mA) computed tomographic (CT) technique with a high-tube-voltage (140 kVp) CT protocol for the detection of pancreatic tumors, image quality, and radiation dose during the pancreatic parenchymal phase.
This prospective, single-center, HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained. Twenty-seven patients (nine men, 18 women; mean age, 64 years) with 23 solitary pancreatic tumors underwent dual-energy CT. Two imaging protocols were used: 140 kVp and 385 mA (protocol A) and 80 kVp and 675 mA (protocol B). For both protocols, the following variables were compared during the pancreatic parenchymal phase: contrast enhancement for the aorta, the pancreas, and the portal vein; pancreas-to-tumor contrast-to-noise ratio (CNR); noise; and effective dose. Two blinded, independent readers qualitatively scored the two data sets for tumor detection and image quality. Random-effect analysis of variance tests were used to compare differences between the two protocols.
Compared with protocol A, protocol B yielded significantly higher contrast enhancement for the aorta (508.6 HU vs 221.5 HU, respectively), pancreas (151.2 HU vs 67.0 HU), and portal vein (189.7 HU vs 87.3 HU), along with a greater pancreas-to-tumor CNR (8.1 vs 5.9) (P < .001 for all comparisons). No statistically significant difference in tumor detection was observed between the two protocols. Although standard deviation of image noise increased with protocol B (11.5 HU vs 18.6 HU), this protocol significantly reduced the effective dose (from 18.5 to 5.1 mSv; P < .001).
A low-tube-voltage, high-tube-current CT technique has the potential to improve the enhancement of the pancreas and peripancreatic vasculature, improve tumor conspicuity, and reduce patient radiation dose during the pancreatic parenchymal phase.
在胰腺实质期，对低管电压（80kVp）、高管电流（675mA）的计算机断层扫描（CT）技术与高管电压（140kVp）CT 方案进行个体内比较，以检测胰腺肿瘤、图像质量和辐射剂量。
本前瞻性、单中心、符合 HIPAA 标准的研究经机构审查委员会批准，并获得了书面知情同意。27 例 23 个孤立性胰腺肿瘤患者（9 名男性，18 名女性；平均年龄 64 岁）行双能 CT 检查。采用两种成像方案：140kVp 与 385mA（方案 A）和 80kVp 与 675mA（方案 B）。在胰腺实质期，比较两种方案下的以下变量：主动脉、胰腺和门静脉的对比增强；胰腺与肿瘤的对比噪声比（CNR）；噪声；有效剂量。两位盲法、独立的读者对两种数据集进行肿瘤检测和图像质量的定性评分。采用随机效应方差分析检验比较两种方案之间的差异。
与方案 A 相比，方案 B 使主动脉（分别为 508.6HU 与 221.5HU）、胰腺（分别为 151.2HU 与 67.0HU）和门静脉（分别为 189.7HU 与 87.3HU）的对比增强显著提高，胰腺与肿瘤的 CNR 也更大（分别为 8.1 与 5.9）（所有比较 P＜0.001）。两种方案之间的肿瘤检出率无统计学差异。虽然方案 B 图像噪声的标准差增加（分别为 11.5HU 与 18.6HU），但该方案显著降低了有效剂量（从 18.5mSv 降至 5.1mSv；P＜0.001）。
低管电压、高管电流 CT 技术有可能提高胰腺和胰周血管的增强程度，提高肿瘤的显示程度，并降低胰腺实质期的患者辐射剂量。
