Abdom Radiol (NY). 2026 Feb 21. doi: 10.1007/s00261-026-05406-3. Online ahead of print.
ABSTRACT
OBJECTIVE: Traditional MRI often requires breath-holding, which is challenging for some patients. This study investigates the Liver Acceleration Volume Acquisition-Flexible (LAVA-Flex) sequence using Cartesian sampling. We aim to assess how various combinations of compressed sensing (CS) and number of excitations (NEX) parameters affect image quality and scanning time for liver MRI under free-breathing conditions. Our goal is to identify the optimal parameter combination and offer a liver imaging protocol that is easily applicable for patients who cannot hold their breath.
METHOD: In this preliminary study, six CS-NEX parameter combinations were tested on healthy volunteers using a 3.0 T MRI: Group A (CS1.2/NEX2), Group B (CS2/NEX5), Group C (CS2/NEX6), Group D (CS2/NEX7), Group E (CS2.5/NEX5), and Group F (CS2.5/NEX6). Objective evaluation indicators included the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective assessment employed a 5-point scoring system to evaluate liver margin sharpness, vascular clarity, respiratory motion artifacts, and overall diagnostic value. Statistical analysis was performed using one-way analysis of variance (ANOVA), the Kruskal-Wallis test, and the weighted kappa test, with P < 0.05 considered statistically significant.
RESULT: We included a total of 30 volunteers in the study. The scanning times varied significantly across the six groups. Objective assessment indicated that the SNR increased progressively with the optimization of the CS-NEX combination, whereas the CNR did not differ significantly between groups. Subjectively, Group A scored the lowest for image quality, while Groups D to F scored the highest. Group E, with the shortest scanning time, achieved the best balance of image quality and efficiency.
CONCLUSION: The combined effect of CS and NEX successfully addressed the challenge of liver imaging during free breathing using traditional MRI equipment. The optimal parameter combination, Group E, achieved the best balance between image quality and time efficiency in 98 s, offering a viable solution for breath-hold-impaired patients.
PMID:41721868 | DOI:10.1007/s00261-026-05406-3
