High-resolution magnetic resonance imaging tracks changes in organ and tissue mass in obese and aging rats

H Tang, JR Vasselli, EX Wu… - American Journal of …, 2002 - journals.physiology.org
H Tang, JR Vasselli, EX Wu, CN Boozer, D Gallagher
American Journal of Physiology-Regulatory, Integrative and …, 2002journals.physiology.org
Magnetic resonance imaging (MRI) has the ability to discriminate between various soft
tissues in vivo. Whole body, specific organ, total adipose tissue (TAT), intra-abdominal
adipose tissue (IAAT), and skeletal muscle (SM) weights determined by MRI were compared
with weights determined by dissection and chemical analysis in two studies with male
Sprague-Dawley rats. A 4.2-T MRI machine acquired high-resolution, in vivo, longitudinal
whole body images of rats as they developed obesity or aged. Weights of the whole body …
Magnetic resonance imaging (MRI) has the ability to discriminate between various soft tissues in vivo. Whole body, specific organ, total adipose tissue (TAT), intra-abdominal adipose tissue (IAAT), and skeletal muscle (SM) weights determined by MRI were compared with weights determined by dissection and chemical analysis in two studies with male Sprague-Dawley rats. A 4.2-T MRI machine acquired high-resolution, in vivo, longitudinal whole body images of rats as they developed obesity or aged. Weights of the whole body and specific tissues were determined using computer image analysis software, including semiautomatic segmentation algorithms for volume calculations. High correlations were found for body weight (r = 0.98), TAT (r = 0.99), and IAAT (r = 0.98) between MRI and dissection and chemical analyses. MRI estimated the weight of the brain, kidneys, and spleen with high accuracy (r > 0.9), but overestimated IAAT, SM, and liver volumes. No differences were detected in organ weights using MRI and dissection measurements. Longitudinal MRI measurements made during the development of obesity and aging accurately represented changes in organ and tissue mass.
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