Background

Although various modifications to the Liver Imaging Reporting and Data System (LI-RADS) at gadoxetic acid–enhanced MRI have been suggested, LI-RADS shows suboptimal sensitivity for hepatocellular carcinoma (HCC) and is perceived to be too complex.

Purpose

To evaluate clinical usefulness of a simplified LI-RADS for diagnosing HCCs of 30 mm or smaller at gadoxetic acid–enhanced MRI.

Materials and Methods

Patients who underwent gadoxetic acid–enhanced MRI examination and subsequent resection, transplantation, or biopsy for focal solid nodules of 30 mm or smaller between January 2019 and December 2020 at a single tertiary referral institution were retrospectively analyzed. Two strategies for simplified LI-RADS using one size criterion (≥10 mm) were evaluated (strategy A, using classifications for nodules of 10–19 mm for nodules both 10–19 mm and ≥20 mm; strategy B, using classifications for nodules ≥20 mm for nodules both 10–19 mm and ≥20 mm). Multivariable analysis was performed to determine significant ancillary features for HCC. Generalized estimating equations were used to compare diagnostic performance for LR-5 (definite HCC) between LI-RADS version 2018 and simplified LI-RADS. The time required for LI-RADS category assignment was compared between the two systems with use of a paired t test.

Results

A total of 645 nodules from 510 patients (mean age ± SD, 60 years ± 10; 393 men) were evaluated. Compared with strategy A, strategy B had a higher sensitivity of 74% (347 of 470 nodules [95% CI: 70, 78]) vs 73% (342 of 470 nodules [95% CI: 69, 77]) (P = .02) with the same specificity of 96% (168 of 175 nodules [95% CI: 92, 98]) vs 96% (168 of 175 nodules [95% CI: 92, 98]) (P > .99). In strategy B, transitional phase hypointensity was an independent ancillary feature for HCC (P = .04) in LR-4 of at least 10 mm with arterial phase hyperenhancement and no other major features. In all 645 nodules, simplified LI-RADS with use of both strategy B and transitional phase hypointensity had a higher sensitivity of 82% (387 of 470 nodules [95% CI: 79, 86]) vs 73% (343 of 470 nodules [95% CI: 69, 77]) (P < .001) than LI-RADS version 2018, without lower specificity (94%, 165 of 175 nodules [95% CI: 90, 97] vs 96%, 168 of 175 nodules [95% CI: 92, 98], P = .08). Compared with LI-RADS version 2018, simplified LI-RADS reduced the time for LI-RADS category assignment (44 seconds ± 23 vs 74 seconds ± 22, P < .001).

Conclusion

A simplified Liver Imaging Reporting and Data System was found to be clinically useful for diagnosing hepatocellular carcinomas of 30 mm or smaller at gadoxetic acid–enhanced MRI.

© RSNA, 2022

Online supplemental material is available for this article.

中文翻译：

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用于肝细胞癌诊断的简化 LI-RADS 加多西酸增强 MRI

背景

尽管已建议对钆塞酸增强 MRI 的肝脏影像报告和数据系统 (LI-RADS) 进行各种修改，但 LI-RADS 对肝细胞癌 (HCC) 的敏感性欠佳，并且被认为过于复杂。

目的

评估简化的 LI-RADS 在钆塞酸增强 MRI 上诊断 30 毫米或更小的 HCC 的临床实用性。

材料和方法

回顾性分析了 2019 年 1 月至 2020 年 12 月期间在一家三级转诊机构接受钆塞酸增强 MRI 检查并随后切除、移植或活检 30 毫米或更小局灶性实性结节的患者。评估了使用一种尺寸标准（≥10 mm）的简化 LI-RADS 的两种策略（策略 A，对 10-19 mm 的结节使用 10-19 mm 和 ≥20 mm 的结节分类；策略 B，对结节使用分类对于 10-19 毫米和 ≥20 毫米的结节，≥20 毫米）。进行多变量分析以确定 HCC 的重要辅助特征。广义估计方程用于比较 LI-RADS 2018 版和简化版 LI-RADS 对 LR-5（明确 HCC）的诊断性能。测试。

结果

对来自 510 名患者（平均年龄 ± SD，60 岁 ± 10；393 名男性）的总共 645 个结节进行了评估。与策略 A 相比，策略 B 的敏感性更高，分别为 74%（470 个结节中的 347 个 [95% CI：70、78]）和 73%（470 个结节中的 342 个 [95% CI：69、77]）（P = .02) 具有相同的特异性，分别为 96%（175 个结节中的 168 个 [95% CI：92、98]）与 96%（175 个结节中的 168 个 [95% CI：92、98]）（P > .99）。在策略 B 中，过渡期低信号是 HCC 的独立辅助特征（P= .04) 在 LR-4 中至少 10 毫米，伴有动脉期强化且无其他主要特征。在所有 645 个结节中，同时使用策略 B 和过渡期低信号的简化 LI-RADS 具有更高的灵敏度，分别为 82%（470 个结节中的 387 个 [95% CI：79、86]）和 73%（470 个结节中的 343 个 [ 95% CI: 69, 77]) ( P < .001) 比 LI-RADS 版本 2018，没有较低的特异性（94%，175 个结节中的 165 个 [95% CI: 90, 97] 对比 96%，175 个结节中的 168 个[95% 置信区间：92、98]，P = .08）。与 LI-RADS 2018 版相比，简化的 LI-RADS 减少了 LI-RADS 类别分配的时间（44 秒±23 vs 74 秒±22，P <.001）。

结论

发现简化的肝脏成像报告和数据系统在临床上可用于在钆塞酸增强 MRI 上诊断 30 毫米或更小的肝细胞癌。

©北美放射学会，2022

本文提供了在线补充材料。