Published online Oct 28, 2022. doi: 10.4329/wjr.v14.i10.352
Peer-review started: August 14, 2022
First decision: August 29, 2022
Revised: September 5, 2022
Accepted: October 5, 2022
Article in press: October 5, 2022
Published online: October 28, 2022
Processing time: 74 Days and 1.5 Hours
Although contrast-enhanced magnetic resonance imaging (MRI) using gadoxetic acid has been shown to have higher accuracy, sensitivity, and specificity for the detection and characterization of hepatic metastases compared with other modalities, the long examination time would limit the broad indication. Several abbreviated MRI protocols without dynamic phases (Ab-MRI) have been proposed to achieve equivalent diagnostic performance for the detection of colorectal liver metastases. However, an optimal protocol has not been established, and no studies have assessed the diagnostic performance of Ab-MRI combined with contrast-enhanced computed tomography (CE-CT), which is the preoperative imaging of colorectal cancer staging in clinical settings, to determine the best therapeutic strategy.
The long examination time and relatively high cost of the standard MRI protocol with gadoxetic acid limit its use for the routine surveillance of liver metastases in patients with colorectal cancer. In order to further expand use of the MRI examination with gadoxetic acid with maintaining the diagnostic performance of liver metastases in patients with colorectal cancer, the diagnostic performance of Ab-MRI combined with or without CE-CT, which is the preoperative imaging of colorectal cancer should be estimated.
To compare the diagnostic performance of two kinds of Ab-MRI protocol with the standard MRI protocol and a combination of the Ab-MRI protocol and CE-CT for the detection of colorectal liver metastases.
Study participants comprised 87 patients (51 males, 36 females; mean age, 67.2 ± 10.8 years) who had undergone gadoxetic acid-enhanced MRI and CE-CT during the initial work-up for colorectal cancer from 2010 to 2021. Each exam was independently reviewed by two readers in three reading sessions: (1) Only single-shot fast spin echo (FSE) T2-weighted or fat-suppressed-FSE-T2-weighted, diffusion-weighted, and hepatobiliary-phase images (Ab-MRI protocol 1 or 2); (2) all acquired MRI sequences (standard protocol); and (3) a combination of an Ab-MRI protocol (1 or 2) and CE-CT. Diagnostic performance was then statistically analyzed.
A total of 380 Lesions were analyzed, including 195 metastases (51.4%). Results from the two Ab-MRI protocols were similar. The sensitivity, specificity, and positive and negative predictive values from Ab-MRI were non-inferior to those from standard MRI (P > 0.05), while those from the combination of Ab-MRI protocol and CE-CT tended to be higher than those from Ab-MRI alone, although the difference was not significant (P > 0.05), and were quite similar to those from standard MRI (P > 0.05).
The diagnostic performances of two kinds of Ab-MRI protocol, including SSFSE or FSE T2-weighted images, were non-inferior to that of the standard protocol. The combination of Ab-MRI and CE-CT provided better diagnostic performance than Ab-MRI alone, nearly equivalent to that of the standard protocol.
The combination of Ab-MRI and CE-CT can provide a sufficient diagnostic performance for the detection of colorectal liver metastases, and enable a reduction in imaging acquisition time.