(MICA) Muscle Imaging for Clinical Applications

Malnutrition and subsequent muscle wasting in hospitalized patients are major problems that adversely impact quality of life, functional performance, health care costs, and survival. Structural changes describing muscle quality may present early in hospital admission and identify as a marker for timely nutritional intervention. Although the clinical characterization of muscle quality may provide insight for optimizing nutritional therapy and health outcomes, clinicians currently lack valid bedside tools of assessment and the comprehensive context needed to interpret such measures. This is a major obstacle to providing meaningful nutrition therapy. Our long-term goal is to improve health outcomes in all clinical populations suffering from malnutrition. In this proposal, we plan to validate our findings from a pilot study comparing muscle quality biomarkers, increase the number of muscle health assessment methods, incorporate diet, and expand our design from a cross-sectional analysis to a longitudinal design to identify health outcomes over time associated with poor muscle quality in disease and aging. The rationale is that validating objective biomarkers of disease and age-specific muscle quality will initiate a new approach that will lead to targeted nutrition intervention and help clarify the role of nutrition in mitigating the effects of disease, aging, and health outcomes.
In this longitudinal, observational study, we plan to quantify muscle quality using ultrasound-based shear wave elastography and B-mode ultrasound, and bioimpedance spectroscopy compared against accepted reference methods of magnetic resonance imaging (MRI) (i.e. chemical-shift encoded MRI to quantify proton density fat fraction and T2 mapping) and muscle biopsy among a healthy younger group, healthy group, and an older group affected by lung cancer. We are continuing this track of inquiry from an IRB-approved pilot study (IRB ID: 2018-0730). To further understand the clinical applicability of these muscle quality measures, we will assess muscle strength and function, diet, and follow participants for 5 years from the first study visit using their electronic medical records to determine the impact of muscle quality on health outcomes. This study aims to provide clinicians valuable data to initiate a methodology lending to the objective identification of muscling wasting, malnutrition, and targeted therapy necessary to improve muscle quality and overall, patient health outcomes. Together, the results from this investigation may profoundly impact the way age- and disease-related changes of muscle quality are clinically identified and show the impact of poor muscle quality on health outcomes leading to a physiological approach for improving therapeutic regimens.