Motivation: Renal oxygen utilization is a potentially valuable biomarker of kidney function. However, quantification of individual kidney oxygen consumption can be challenging. Bilateral renal metabolic rate of oxygen (rblMRO2) has been previously reported by our group, though, under breath-held conditions. Goal(s): Evaluate feasibility of rblMRO2 quantification during free-breathing. Approach: A one-minute MRI pulse sequence was implemented during free-breathing to simultaneously measure two parameters (venous oxygen saturation and blood flow rate) at two locations (inferior vena cava, above and below the renal vasculature), yielding four total parameters. Measurements were also made under breath-held conditions. Results: Free-breathing, dual-band, and breath-held measurements of rblMRO2 were plausible. Impact: MRI-methods to evaluate renal metabolism may be limited by difficulty with identifying individual kidney's vasculature and breath-holds. Here, a free-breathing approach is implemented to quantify metabolism of both kidneys by imaging the (larger) inferior-vena-cava. These aspects may facilitate clinical translation.
Deshpande et al. (Tue,) studied this question.