Quantification of Fat Concentration and Vascular Response in Brown and White Adipose Tissue of Rats by Spectral CT Imaging
Korean Journal of Radiology
;
: 248-256, 2020.
Article
in English
| WPRIM
| ID: wpr-782102
ABSTRACT
OBJECTIVE: The purpose of the study was to non-invasively characterize and discriminate brown adipose tissue (BAT) from white adipose tissue (WAT) in rats using spectral computed tomography (CT) with histological validation.MATERIALS AND METHODS:
A lipid-containing phantom (lipid fractions from 0% to 100%) was imaged with spectral CT. An in vivo, non-enhanced spectral CT scan was performed on 24 rats, and fat concentrations of BAT and WAT were measured. The rats were randomized to receive intraperitoneal treatment with norepinephrine (NE) (n = 12) or saline (n = 12). Non-enhanced and enhanced spectral CT scans were performed after treatment to measure the elevation of iodine in BAT and WAT. The BAT/aorta and WAT/aorta ratios were calculated and compared, after which isolated BAT and WAT samples were subjected to histological and uncoupling protein 1 (UCP1) analyses.RESULTS:
The ex-vivo phantom study showed excellent linear fit between measured fat concentration and the known gravimetric reference standard (r² = 0.996). In vivo, BAT had significantly lower fat concentration than WAT (p < 0.001). Compared to the saline group, the iodine concentration of BAT increased significantly (p < 0.001) after injection of NE, while the iodine concentration of WAT only changed slightly. The BAT/aorta ratio also increased significantly after exposure to NE compared to the saline group (p < 0.001). Histological and UCP1 expression analyses supported the spectral CT imaging results.CONCLUSION:
The study consolidates spectral CT as a new approach for non-invasive imaging of BAT and WAT. Quantitative analyses of BAT and WAT by spectral CT revealed different characteristics and pharmacologic activations in the two types of adipose tissue.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Adipose Tissue, Brown
/
Norepinephrine
/
Tomography, X-Ray Computed
/
Adipose Tissue
/
Adipose Tissue, White
/
Iodine
Limits:
Animals
Language:
English
Journal:
Korean Journal of Radiology
Year:
2020
Type:
Article
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