Proton MR Spectroscopy Measurements of White and Brown Adipose Tissue in Healthy Humans: Relaxation Parameters and Unsaturated Fatty Acids

Autor: Kong Y. Chen, Ahmed Hamimi, Zahraa Abdul Sater, Jatin R. Matta, Janet F. Eary, Ahmed M. Gharib, Ronald Ouwerkerk, Khaled Z. Abd-Elmoniem, Aaron M. Cypess
Rok vydání: 2021
Předmět:
In vivo magnetic resonance spectroscopy
Adult
Male
Relaxometry
medicine.medical_specialty
Adipose Tissue
White
Proton Magnetic Resonance Spectroscopy
Adipose tissue
White adipose tissue
Sensitivity and Specificity
030218 nuclear medicine & medical imaging
03 medical and health sciences
0302 clinical medicine
Adipose Tissue
Brown
Fluorodeoxyglucose F18
Diabetes mellitus
Internal medicine
Positron Emission Tomography Computed Tomography
Brown adipose tissue
medicine
Lipolysis
Humans
Radiology
Nuclear Medicine and imaging
Prospective Studies
Aged
chemistry.chemical_classification
business.industry
Middle Aged
medicine.disease
Healthy Volunteers
medicine.anatomical_structure
Endocrinology
chemistry
030220 oncology & carcinogenesis
Fatty Acids
Unsaturated
Female
Radiopharmaceuticals
business
Polyunsaturated fatty acid
Zdroj: Radiology. 299(2)
ISSN: 1527-1315
0156-8671
Popis: Background Activation of brown adipose tissue (BAT) in rodents increases lipolysis in white adipose tissue (WAT) and improves glucose tolerance. Adult humans can have metabolically active BAT. Implications for diabetes and obesity in humans require a better characterization of BAT in humans. Purpose To study fat depots with localized proton MR spectroscopy relaxometry and to identify differences between WAT and fluorine 18 fluorodeoxyglucose (FDG) PET/CT proven cold-activated BAT in humans. Materials and Methods Participants were consecutively enrolled in this prospective study (ClinicalTrials.gov identifiers: NCT01568671 and NCT01399385) from August 2016 to May 2019. Supraclavicular potential BAT regions were localized with MRI. Proton densities, T1, and T2 were measured with localized MR spectroscopy in potential BAT and in subcutaneous WAT. FDG PET/CT after cold stimulation was used to retrospectively identify active supraclavicular BAT or supraclavicular quiescent adipose tissue (QAT) regions. MR spectroscopy results from BAT and WAT were compared with grouped and paired tests. Results Of 21 healthy participants (mean age, 36 years ± 16 [standard deviation]; 13 men) FDG PET/CT showed active BAT in 24 MR spectroscopy-targeted regions in 16 participants (eight men). Four men had QAT. The T2 for methylene protons was shorter in BAT (mean, 69 msec ± 6, 24 regions) than in WAT (mean, 83 msec ± 3, 18 regions, P < .01) and QAT (mean, 78 msec ± 2, five regions, P < .01). A T2 cut-off value of 76 msec enabled the differentiation of BAT from WAT or QAT with a sensitivity of 85% and a specificity of 95%. Densities of protons adjacent and between double bonds were 33% and 24% lower, respectively, in BAT compared with those in WAT (P = .01 and P = .03, respectively), indicating a lower content of unsaturated and polyunsaturated fatty acids, respectively, in BAT compared with WAT. Conclusion Proton MR spectroscopy showed shorter T2 and lower unsaturated fatty acids in brown adipose tissue (BAT) than that in white adipose tissue in healthy humans. It was feasible to identify BAT with MR spectroscopy without the use of PET/CT or cold stimulation. © RSNA, 2021 See also the editorial by Barker in this issue. Online supplemental material is available for this article.
Databáze: OpenAIRE
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