Fig. 2: Dynamic Cr-CEST MRI and [18F]FDG PET and CT detect the response to saline and the β3-adrenergic receptor agonist CL.
From: Non-invasive mapping of brown adipose tissue activity with magnetic resonance imaging
a–d, Dynamic Cr-CEST MRI (n = 6) and [18F]FDG PET and CT (n = 4) of interscapular fat depots after intraperitoneal injection with saline in rats: representative images (Cr-CEST % (a), FDG uptake SUV (c)) and signals (Cr-CEST % (b), FDG uptake SUVmean (d)). Representative image from n = 6 in Cr-CEST MRI and n = 4 in [18F]FDG PET and CT). e–h, Dynamic Cr-CEST MRI (n = 6) and [18F]FDG PET and CT (n = 3) of interscapular fat depots after intraperitoneal injection with CL (1.0 mg kg−1) in rats: representative images (Cr-CEST % (e), FDG uptake SUVmean (g)) and signals (Cr-CEST % (f), FDG uptake SUVmean (h)). Representative image from n = 6 in Cr-CEST MRI and n = 3 in [18F]FDG PET and CT). i, 1H-NMR analysis of BAT creatine concentration; the creatine concentration of BAT increased after the administration of CL (1.0 mg kg−1, n = 8, a separate cohort from f). j, Linear regression analysis of Cr-CEST MRI in relation to creatine concentration (cohorts in f,i). k–n, Real-time PCR analysis of thermogenesis-related gene expression due to CL (1.0 mg kg−1) in the BAT of rats; all experiments were repeated at least twice with similar results (n = 8). k, DIO2. l, PPARG1α. m, CKB. n, UCP1. o, Dynamic OCR of rats under saline (n = 6) or CL (n = 8) stimulation. Data are presented as the mean ± s.e.m. Statistical analysis was performed using two-tailed paired (f,o) and unpaired (i,k–n) Student’s t-tests; each time point (10–120 min) was compared to 0 min (f,i,k–n) and −10 min (o), respectively. In the T2-weighted and CT images, the arrowheads indicate the BAT and WAT regions, respectively.
