Editorial for “The Use of Non‐Contrast Abbreviated MRI for the Detection of Recurrent Hepatocellular Carcinoma in Postoperative Surveillance”

In this issue of the Journal of Magnetic Resonance Imaging, a study is presented by Chen and co-workers, evaluating the role of non-contrast abbreviated MRI (AMRI) for the detection of recurrent hepatocellular carcinoma in postoperative surveillance [1]. With the advances in management strategy, long-term survival in hepatocellular carcinoma (HCC) remains unsatisfactory, with a 5-year recurrence rate ranging from 50% to 70%. The rationale for surveillance is to detect patients with asymptomatic HCC at an early stage to assist the progress of curative therapy. In regard to improving patients' prognosis, by increasing early diagnosis and applicability of therapeutic managements, international guidelines recommend periodic surveillance in patients at risk of developing HCC [2-5]. HCC recurrence is commonly classified into early and late recurrence using a 2-year cutoff point. Early recurrence accounting for more than 70% of all tumor recurrences, and is associated with significantly poorer overall survival compared to late recurrence [6]. Early detection of recurrent disease provides a pivotal therapeutic window for potentially curative or life-prolonging second-line therapeutic procedures, including repeat hepatectomy, radiofrequency ablation, transarterial chemoembolization, transarterial radioembolization, and liver transplantation, as in the management strategy for initially diagnosed HCCs. Magnetic resonance imaging (MRI) is the most sensitive imaging technique for the detection of both initial and recurrent HCCs [7]. However, its routine application in surveillance programs remains limited due to high costs and prolonged acquisition times. AMRI is not a novel concept and has been used in other clinical settings, including breast cancer screening, hepatic steatosis and fibrosis assessment, and surveillance of pancreatic cysts, adrenal lesions, renal masses, and gynecologic pathologies. In the context of HCC, several AMRI protocols have been proposed, including nonenhanced, dynamic contrast-enhanced, and hepatobiliary phase–based approaches. There is a critical need for a reliable imaging technique for both HCC surveillance in at-risk populations and post-treatment recurrence assessment. The study by Chen et al. published in this issue of the Journal of Magnetic Resonance Imaging enrolled 190 patients with established HCC who experienced hepatic resection as an initial treatment, of whom 88 cases presented with recurrent HCCs [1]. All patients underwent a 1.5 Tesla or 3 Tesla MRI examination using their standard abdominal MRI protocol. The NC-AMRI protocol, comprising axial fat-suppressed T2WI and DWI, was extracted from routine full MRI protocol. NC-AMRI results were deemed positive in the presence of a lesion revealing diffusion restriction and/or exhibiting mild-to-moderate hyperintensity on T2-weighted sequences. Intrahepatic recurrent HCC was confirmed upon identification of new hepatic lesions on the index examination that were either histopathologically proven or met established imaging and clinical diagnostic criteria for HCC. Recurrent lesions were not stratified into early and late recurrence groups. Particularly, the ratio of patients with adequately extended follow-up to enable the assessment of late recurrence was markedly limited relative to the overall cohort. Optimal AFP and PIVKA-II cut-off values were determined by maximizing the Youden index. Pairwise comparisons were conducted among three strategies: combined NC-AMRI, AFP, and PIVKA-II; NC-AMRI alone; and complete MRI. Diagnostic performance among the three strategies was compared using marginal logistic regression with generalized estimating equations and McNemar's test. The authors reported comparable diagnostic performance between NC-AMRI and complete MRI for intrahepatic recurrent HCC detection, including small lesions. This study is retrospective in design, inherently introducing potential selection bias. Additional selection bias may also arise from the related inclusion and exclusion criteria. Furthermore, the absence of per-lesion analysis should be acknowledged as a potential source of bias, as lesion-based assessments in multifocal disease may overestimate diagnostic sensitivity. The use of different MRI systems without assessing inter-system reliability introduces variability that was not properly evaluated. The diagnostic role of medical imaging is rapidly evolving beyond conventional diagnosis to involve an essential role in personalized precision medicine. MRI-based decision-support systems for precision diagnosis and treatment could be a promising tool in modern medicine. With the emergence of brief AMRI techniques, the development of novel sensitive and specific imaging strategies to monitor early HCCs and recurrent HCCs is in the scope of researchers and clinicians. Identifying a suitable short MRI protocol capable of detecting HCC at its earliest stage is not far away from insight. However, further comprehensive prospective studies are still required to establish standardized AMRI protocols and evaluate their clinical utility across key endpoints, including diagnosis, prognosis, and treatment response in patients with HCCs. Ultimately, future prospective studies integrated into routine imaging practice are essential to provide a more reliable picture of the incremental value of AMRI in the detection and monitoring of early and recurrent HCCs.