Point‐of‐care magnetic resonance technology to measure liver fat: Phantom and first‐in‐human pilot study

Abstract

Purpose To assess feasibility and accuracy of point‐of‐care (POC) NMR‐proton density fat fraction (PDFF) in phantoms and in a human pilot study in a POC setting. Methods POC NMR (LiverScope, Livivos, San Diego CA) PDFF measurements were obtained of certified phantoms with known PDFF values (0%‐40%). In an institutional review board‐approved, Health Insurance Portability and Accountability Act‐compliant prospective human study, a convenience sample of participants from an obesity clinic was enrolled (November 2020 to June 2021). The inclusion criteria required body mass index (BMI) = 27‐40 kg/m2 and willingness to undergo POC NMR and MRI‐PDFF measurements. Liver PDFF was measured by POC NMR and, within 35 days after, by a confounder corrected CSE MRI PDFF acquisition and reconstruction method. The adverse events were documented and linear regression analyses were performed. Results POC NMR‐PDFF measurements agreed with known phantom PDFF values (R2 = 0.99). Fourteen participants were enrolled in the pilot human study. MRI‐PDFF could not be obtained in 4 participants (claustrophobia reaction, n = 3, exceeded size of MR scanner bore, n = 1). POC NMR was unevaluable in 2 participants (insufficient signal penetration depth, n = 1, failure to comply with instructions, n = 1). Technical success was 11 of 13 (85%) for POC NMR PDFF. In 7 participants (4 female; 31‐74 years old; median BMI 35 kg/m2), MRI‐PDFF (range, 2.8%‐18.1%), and POC NMR‐PDFF (range, 3%‐25.2%), agreed with R2 = 0.94. POC NMR had no adverse events. Conclusion POC NMR measures PDFF accurately in phantoms and, in a first‐in‐human pilot study, is feasible and accurate in adults with obesity. Further testing to determine precision and accuracy across larger and more diverse cohorts is needed.

Strategies and Techniques for Liver Magnetic Resonance Imaging: New and Pending Applications for Routine Clinical Practice

“…These techniques are expected to play an important role in the context of abbreviated MRI in combination with PDFF measurements for the evaluation of diffuse liver diseases, including NAFLD and NASH [ 26 52 ]. Finally, improving the cost-effectiveness of these applications by adopting low-field point-of-care MRI [ 53 ] will help to further popularize the implementation of MRI for the evaluation of diffuse liver disease.…”

Risk stratification and early detection biomarkers for precision HCC screening

“…[63] Point-of-care biochemical tests and imaging devices have been actively explored as potential options to substantially improve receipt of the regular screening examination, particularly in developing regions with limited access to medical care. [64][65][66][67] These new technologies could be combined with software as a medical device (SaMD), incorporating artificial intelligence (AI) and machine learning/deep learning (ML/DL) for widespread application. [68] Several promising examples are overviewed in the following sections.…”

“…A functional in vivo genetic screening suggested that there may be a new class of HCC risk‐associated DNA variants (somatic DNA mutations in PKD1 [encoding polycystin 1, transient receptor potential channel interacting], KMT2D [encoding lysine methyltransferase 2D], and ARID1A [encoding AT‐rich interaction domain 1A] genes) in cirrhotic liver that confers a protective effect against carcinogenesis 63. Point‐of‐care biochemical tests and imaging devices have been actively explored as potential options to substantially improve receipt of the regular screening examination, particularly in developing regions with limited access to medical care 64–67. These new technologies could be combined with software as a medical device (SaMD), incorporating artificial intelligence (AI) and machine learning/deep learning (ML/DL) for widespread application 68.…”

New clinical opportunities of low-field MRI: heart, lung, body, and musculoskeletal

“…We do not cover interventional applications, as they are described by several other recent review papers [ 11 , 21 , 22 ]. We do not cover point-of-care body MRI systems [ 23 ], such as the prostate [ 24 ], or liver [ 25 , 26 ] scanners, because these systems operate at a much lower field strength (< 0.1 T) and are designed for a single or a few applications, and are, therefore, not suitable for general-purpose body imaging. The results discussed in this paper come primarily from whole-body systems such as the 0.35 T (Viewray) [ 14 ], 0.55 T (“ramped down” Siemens Aera [ 11 ] and Siemens Free.Max [ 12 ]), and 0.75 T (“ramped down” Philips Achieva) [ 13 ], with specifications listed in Table 2 .…”