90kVp 下个体体重适应对比剂应用于肝脏计算机断层成像

Individually Body Weight-Adapted Contrast Media Application in Computed Tomography Imaging of the Liver at 90 kVp.

机构信息

From the Department of Radiology and Nuclear Medicine; and CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, the Netherlands.

出版信息

Invest Radiol. 2019 Mar;54(3):177-182. doi: 10.1097/RLI.0000000000000525.

DOI:10.1097/RLI.0000000000000525

PMID:30721159

Abstract

OBJECTIVES

The aim of the present study was to evaluate the attenuation and image quality (IQ) of a body weight-adapted contrast media (CM) protocol compared with a fixed injection protocol in computed tomography (CT) of the liver at 90 kV.

MATERIALS AND METHODS

One hundred ninety-nine consecutive patients referred for abdominal CT imaging in portal venous phase were included. Group 1 (n = 100) received a fixed CM dose with a total iodine load (TIL) of 33 g I at a flow rate of 3.5 mL/s, resulting in an iodine delivery rate (IDR) of 1.05 g I/s. Group 2 (n = 99) received a body weight-adapted CM protocol with a dosing factor of 0.4 g I/kg with a subsequent TIL adapted to the patients' weight. Injection time of 30 seconds was kept identical for all patients. Therefore, flow rate and IDR changed with different body weight. Patients were divided into 3 weight categories; 70 kg or less, 71 to 85 kg, and 86 kg or greater. Attenuation (HU) in 3 segments of the liver, signal-to-noise ratio, and contrast-to-noise ratio were used to evaluate objective IQ. Subjective IQ was assessed by a 5-point Likert scale. Differences between groups were statistically analyzed (P < 0.05 was considered statistically significant).

RESULTS

No significant differences in baseline characteristics were found between groups. The CM volume and TIL differed significantly between groups (P < 0.01), with mean values in group 1 of 110 mL and 33 g I, and in group 2 of 104.1 ± 21.2 mL and 31.2 ± 6.3 g I, respectively. Flow rate and IDR were not significantly different between groups (P > 0.05). Body weight-adapted protocoling led to more homogeneous enhancement of the liver parenchyma compared with a fixed protocol with a mean enhancement per weight category in group 2 of 126.5 ± 15.8, 128.2 ± 15.3, and 122.7 ± 21.2 HU compared with that in group 1 of 139.9 ± 21.4, 124.6 ± 24.8, and 116.2 ± 17.8 HU, respectively.

CONCLUSIONS

Body weight-adapted CM injection protocols result in more homogeneous enhancement of the liver parenchyma at 90 kV in comparison to a fixed CM volume with comparable objective and subjective IQ, whereas overall CM volume can be safely reduced in more than half of patients.

摘要

目的

本研究旨在评估体重适应性对比剂（CM）方案与 90kV 下肝脏门静脉期 CT 检查中固定注射方案相比的衰减和图像质量（IQ）。

材料与方法

共纳入 199 例连续行腹部 CT 成像的患者，其中 100 例（组 1）接受固定 CM 剂量，总碘负荷（TIL）为 33gI，流速为 3.5mL/s，碘输送率（IDR）为 1.05gI/s。99 例（组 2）接受体重适应性 CM 方案，剂量系数为 0.4gI/kg，随后根据患者体重调整 TIL。所有患者的注射时间均保持 30 秒不变。因此，不同体重下的流速和 IDR 会发生变化。患者被分为 3 个体重类别：70kg 或以下、71-85kg 和 86kg 或以上。使用肝脏 3 个节段的衰减（HU）、信噪比和对比噪声比来评估客观 IQ。主观 IQ 通过 5 分李克特量表进行评估。对组间差异进行统计学分析（P<0.05 被认为具有统计学意义）。

结果

两组间的基线特征无显著差异。CM 体积和 TIL 组间差异有统计学意义（P<0.01），组 1 的平均值分别为 110mL 和 33gI，组 2 的平均值分别为 104.1±21.2mL 和 31.2±6.3gI。组间流速和 IDR 无显著差异（P>0.05）。与固定方案相比，体重适应性方案可使肝实质增强更均匀，组 2 中每个体重类别的平均增强值分别为 126.5±15.8、128.2±15.3 和 122.7±21.2HU，而组 1 中的值分别为 139.9±21.4、124.6±24.8 和 116.2±17.8HU。