Evaluation of an equilibrium phase free-breathing dynamic contrast-enhanced MRI prototype sequence compared to traditional breath-held MRI acquisition in liver oncology patients

Introduction: Magnetic Resonance Imaging (MRI) is a commonly used for diagnosing metastatic liver disease. When patients are unable to achieve the necessary arrested respiration required during image acquisition, image artefacts occur that affect image quality and diagnostic value. The main contribution of this study is the evaluation of a novel prototype technique that allows a specific sub-group of patients to breathe freely throughout the acquisition of dynamic contrast enhanced equilibrium phase MRI of the liver.

Methods: The study compared a traditional single phase of arrested respiration T1-weighted (T1W) fat saturated (FatSat) volumetric interpolated breath-hold sequence (VIBE) with a novel free-breathing T1W 3D Radial VIBE prototype sequence. A cohort of patients (n=30) with known hepatic metastases who demonstrated difficulty in complying with the instructions for arrested inspiration were scanned. Both sets of data were compared for diagnostic quality using a Likert scale questionnaire by specialist Oncology Radiologists (n=2).

Results: Higher scores for all image quality criteria, including the presence of artefact (2.6 + 0.57; p <0.001), lesion conspicuity (2.9 + 0.35; p <0.001) and visibility of intra-hepatic vessels (2.8 + 0.37; p <0.001) were found using the free-breathing sequence (13.5 + 1.94; p <0.001 t=13.31; df 29; p <0.001) than the breath hold phase (8.1 + 2.06), confirmed with kappa (k-0.023; p-0.050).

Conclusions: The results demonstrated a 39.5% improvement in overall image quality using the T1W 3D Radial VIBE prototype sequence, and has the potential to improve patient experience and reduce image artefacts during MRI imaging of this sub-group of patients.