Zhang X, Huang H, Huang Y, Sun Y, Chen Z, Chen M, Xu J
Department of Radiology, Southern University of Science and Technology Hospital, Shenzhen, Guangdong, China.
Department of Radiology, Southern University of Science and Technology Hospital, Shenzhen, Guangdong, China.
Clin Radiol. 2025 Jul;86:106944. doi: 10.1016/j.crad.2025.106944. Epub 2025 Apr 30.
To evaluate the image quality and diagnostic value of a body mass index (BMI)-based dual-energy computed tomography (CT) protocol in computed tomography pulmonary angiography (CTPA) for reduction of radiation dose and contrast medium (CM) volume.
Patients suspected of having pulmonary embolism were prospectively included and randomly assigned to one of three protocols: Protocol A (a standard protocol, 100 kV/140 mAs/50 mL iodinated CM), B (a conventional dual-energy protocol, 80-140 kV switching/automatic tube current/weight-dependent CM volume) and C (a BMI-based dual-energy protocol, 80-140 kV switching/BMI-based tube current/weight-dependent CM volume, BMI-based CM injection rate). Subjective and objective image analysis were performed by two radiologists independently. Diagnostic accuracy of pulmonary embolism were evaluated. Inter-group comparison was performed.
Ninety patients (mean age 54.1 ± 13.3 years, 57 men) were included, with 30 patients in each group. The CT values, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the pulmonary arteries in group C were significantly higher than those in group B (358.2 ± 50.5 vs 324.9 ± 57.2, p=0.047, 17.8 ± 3.2 vs 15.3 ± 2.9, p=0.010, 19.2 ± 4.1 vs 15.7 ± 3.8, p=0.014). The dose length product (DLP) and CM volume were significantly reduced in groups B and C (A vs B vs C, DLP, 287.9 ± 34.0 vs 177.2 ± 39.2 vs 183.8 ± 23.1 mGy·cm), p<0.001, CM, 50.0 ± 0.0 vs 22.1 ± 3.0 vs 23.2 ± 4.0 ml, p<0.001). There were no significant differences in diagnostic accuracy or subjective image quality among the three groups.
The BMI-based dual-energy CT protocol can reduce radiation exposure and iodine burden compared to routine CTPA without affecting the image quality and diagnostic accuracy in patients with a BMI under 30 kg/m.
评估基于体重指数（BMI）的双能量计算机断层扫描（CT）方案在计算机断层扫描肺动脉造影（CTPA）中对降低辐射剂量和对比剂（CM）用量的图像质量及诊断价值。
前瞻性纳入疑似肺栓塞患者并随机分为三个方案组：方案A（标准方案，100 kV/140 mAs/50 mL碘化CM）、B（传统双能量方案，80 - 140 kV切换/自动管电流/体重依赖CM用量）和C（基于BMI的双能量方案，80 - 140 kV切换/BMI依赖管电流/体重依赖CM用量、BMI依赖CM注射速率）。由两名放射科医生独立进行主观和客观图像分析。评估肺栓塞的诊断准确性。进行组间比较。
纳入90例患者（平均年龄54.1±13.3岁，57例男性），每组30例。C组肺动脉的CT值、信噪比（SNR）和对比噪声比（CNR）显著高于B组（358.2±50.5对324.9±57.2，p = 0.047；17.8±3.2对15.3±2.9，p = 0.010；19.2±4.1对15.7±3.8，p = 0.014）。B组和C组的剂量长度乘积（DLP）和CM用量显著降低（A组对B组对C组，DLP，287.9±34.0对177.2±39.2对183.8±23.1 mGy·cm），p<0.001；CM用量，50.0±0.0对22.1±3.0对23.2±4.0 ml，p<0.001）。三组间诊断准确性或主观图像质量无显著差异。
对于BMI低于30 kg/m²的患者，基于BMI的双能量CT方案与常规CTPA相比，可减少辐射暴露和碘负荷，且不影响图像质量和诊断准确性。
