光子计数CT肝脏脂肪定量与临床MRI的直接比较——初步经验

Liver fat quantification in photon counting CT in head to head comparison with clinical MRI - First experience.

作者信息

Schwartz Fides Regina, Ashton Jeffrey, Wildman-Tobriner Benjamin, Molvin Lior, Ramirez-Giraldo Juan Carlos, Samei Ehsan, Bashir Mustafa Rifaat, Marin Daniele

机构信息

Duke University Health System, Department of Radiology, United States.

Siemens Healthineers, Malvern, PA, United States.

出版信息

Eur J Radiol. 2023 Apr;161:110734. doi: 10.1016/j.ejrad.2023.110734. Epub 2023 Feb 9.

DOI:10.1016/j.ejrad.2023.110734

PMID:36842273

Abstract

PURPOSE

To compare liver fat quantification between MRI and photon-counting CT (PCCT).

METHOD

A cylindrical phantom with inserts containing six concentrations of oil (0, 10, 20, 30, 50 and 100%) and oil-iodine mixtures (0, 10, 20, 30 and 50% fat +3 mg/mL iodine) was imaged with a PCCT (NAEOTOM Alpha) and a 1.5 T MRI system (MR 450w, IDEAL-IQ sequence), using clinical parameters. An IRB-approved prospective clinical evaluation included 12 obese adult patients with known fatty liver disease (seven women, mean age: 61.5 ± 13 years, mean BMI: 30.3 ± 4.7 kg/m). Patients underwent a same-day clinical MRI and PCCT of the abdomen. Liver fat fractions were calculated for four segments (I, II, IVa and VII) using in- and opposed-phase on MRI ((Mean - Mean)/2*Mean) and iodine-fat, tissue decomposition analysis in PCCT (Syngo.Via VB60A). CT and MRI Fat fractions were compared using two-sample t-tests with equal variance. Statistical analysis was performed using RStudio (Version1.4.1717).

RESULTS

Phantom results showed no significant differences between the known fat fractions (P = 0.32) or iodine (P = 0.6) in comparison to PCCT-measured concentrations, and no statistically significant difference between known and MRI-measured fat fractions (P = 0.363). In patients, the mean fat signal fraction measured on MRI and PCCT was 13.1 ± 9.9% and 12.0 ± 9.0%, respectively, with an average difference of 1.1 ± 1.9% between the modalities (P = 0.138).

CONCLUSION

First experience shows promising accuracy of liver fat fraction quantification for PCCT in obese patients. This method may improve opportunistic screening for CT in the future.

摘要

目的

比较磁共振成像（MRI）与光子计数CT（PCCT）对肝脏脂肪定量的效果。

方法

使用临床参数，对一个带有内含六种不同浓度油（0%、10%、20%、30%、50%和100%）以及油 - 碘混合物（0%、10%、20%、30%和50%脂肪 + 3mg/mL碘）的插入物的圆柱形体模，进行PCCT（NAEOTOM Alpha）和1.5T MRI系统（MR 450w，IDEAL - IQ序列）成像。一项经机构审查委员会批准的前瞻性临床评估纳入了12名已知患有脂肪性肝病的肥胖成年患者（7名女性，平均年龄：61.5 ± 13岁，平均体重指数：30.3 ± 4.7kg/m²）。患者在同一天接受腹部临床MRI和PCCT检查。使用MRI的同相位和反相位图像（(均值 - 均值)/2*均值）以及PCCT中的碘 - 脂肪组织分解分析（Syngo.Via VB60A），计算四个肝段（I、II、IVa和VII）的肝脏脂肪分数。使用等方差双样本t检验比较CT和MRI的脂肪分数。使用RStudio（版本1.4.1717）进行统计分析。

结果

体模结果显示，与PCCT测量的浓度相比，已知脂肪分数（P = 0.32）或碘（P = 0.6）之间无显著差异，已知脂肪分数与MRI测量的脂肪分数之间也无统计学显著差异（P = 0.363）。在患者中，MRI和PCCT测量得到的平均脂肪信号分数分别为13.1 ± 9.9%和12.0 ± 9.0%，两种检查方式之间的平均差异为1.1 ± 1.9%（P = 0.138）。