Deep Learning-Accelerated Non-Contrast Abbreviated Liver MRI for Detecting Malignant Focal Hepatic Lesions: Dual-Center Validation

Objective: To compare a deep learning (DL)-accelerated non-enhanced abbreviated MRI (AMRI_DL) protocol with standard AMRI (AMRI_STD) of the liver in terms of image quality and malignant focal lesion detection. Materials and Methods: This retrospective study included 155 consecutive patients (110 male; mean age 62.4 ± 11 years) from two sites who underwent standard liver MRI and additional AMRI_DL sequences, specifically DL-accelerated single-shot fast-spin echo (SSFSE_DL) and DL-accelerated diffusion-weighted imaging (DWI_DL). Additional MRI phantom experiments assessed signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) values. Three reviewers evaluated AMRI_DL and AMRI_STD protocols for image quality using a five-point Likert scale and identified malignant hepatic lesions. Image quality scores and per-lesion sensitivities were compared between AMRI_DL and AMRI_STD using the Wilcoxon signed-rank test and logistic regression with generalized estimating equations, respectively. Results: Phantom experiments demonstrated comparable SNR and higher CNR for SSFSE_DL compared to SSFSE_STD, with similar ADC values for DWI_DL and DWI_STD. Among the 155 patients, 130 (83.9%) had chronic liver disease or a history of intra-or extrahepatic malignancy. Of 104 malignant focal lesions in 64 patients, 58 (55.8%) were hepatocellular carcinomas (HCCs), 38 (36.5%) were metastases, four (3.8%) were cholangiocarcinomas, and four (3.8%) were lymphomas. The pooled per-lesion sensitivity across three readers was 97.6% for AMRI_DL, comparable to 97.6% for AMRI_STD. Compared with AMRI_STD, AMRI_DL demonstrated superior image quality regarding structural sharpness, artifacts, and noise (all P < 0.001) and reduced the average scan time by approximately 50% (2 min 29 sec vs. 4 min 11 sec). In patients with chronic liver disease, AMRI_DL achieved a 96.6% per-lesion sensitivity for HCC detection, similar to 96.5% for AMRI_STD (P > 0.05). Conclusion: The AMRI_DL protocol offers comparable sensitivity for detecting malignant focal lesions, including HCC while significantly enhancing image quality and reducing scan time by approximately 50% compared to AMRI_STD.