Validation of whole-body magnetic resonance spectroscopy as a tool to assess murine body composition

2000 ◽  
Vol 24 (6) ◽  
pp. 719-724 ◽  
Author(s):  
P Mystkowski ◽  
E Shankland ◽  
SA Schreyer ◽  
RC LeBoeuf ◽  
RS Schwartz ◽  
...  
Keyword(s):  
Body Composition ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Whole Body ◽  
Resonance Spectroscopy

scholarly journals Increased intramyocellular lipid accumulation in HIV-infected women with fat redistribution

2006 ◽  
Vol 100 (2) ◽  
pp. 609-614 ◽  
Author(s):  
Martin Torriani ◽  
Bijoy J. Thomas ◽  
Robert B. Barlow ◽  
Jamie Librizzi ◽  
Sara Dolan ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Composition ◽  
Magnetic Resonance ◽  
Subcutaneous Fat ◽  
Abdominal Fat ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Intramyocellular Lipid ◽  
Fat Redistribution ◽  
Visceral Abdominal Fat

The human immunodeficiency virus (HIV)-lipodystrophy syndrome is associated with fat redistribution and metabolic abnormalities, including insulin resistance. Increased intramyocellular lipid (IMCL) concentrations are thought to contribute to insulin resistance, being linked to metabolic and body composition variables. We examined 46 women: HIV infected with fat redistribution ( n = 25), and age- and body mass index-matched HIV-negative controls ( n = 21). IMCL was measured by 1H-magnetic resonance spectroscopy, and body composition was assessed with computed tomography, dual-energy X-ray absorptiometry (DEXA), and magnetic resonance imaging. Plasma lipid profile and markers of glucose homeostasis were obtained. IMCL was significantly increased in tibialis anterior [135.0 ± 11.5 vs. 85.1 ± 13.2 institutional units (IU); P = 0.007] and soleus [643.7 ± 61.0 vs. 443.6 ± 47.2 IU, P = 0.017] of HIV-infected subjects compared with controls. Among HIV-infected subjects, calf subcutaneous fat area (17.8 ± 2.3 vs. 35.0 ± 2.5 cm2, P < 0.0001) and extremity fat by DEXA (11.8 ± 1.1 vs. 15.6 ± 1.2 kg, P = 0.024) were reduced, whereas visceral abdominal fat (125.2 ± 11.3 vs. 74.4 ± 12.3 cm2, P = 0.004), triglycerides (131.1 ± 11.0 vs. 66.3 ± 12.3 mg/dl, P = 0.0003), and fasting insulin (10.8 ± 0.9 vs. 7.0 ± 0.9 μIU/ml, P = 0.004) were increased compared with control subjects. Triglycerides ( r = 0.39, P = 0.05) and extremity fat as percentage of whole body fat by DEXA ( r = −0.51, P = 0.01) correlated significantly with IMCL in the HIV but not the control group. Extremity fat (β = −633.53, P = 0.03) remained significantly associated with IMCL among HIV-infected patients, controlling for visceral abdominal fat, abdominal subcutaneous fat, and antiretroviral medications in a regression model. These data demonstrate increased IMCL in HIV-infected women with a mixed lipodystrophy pattern, being most significantly associated with reduced extremity fat. Further studies are necessary to determine the relationship between extremity fat loss and increased IMCL in HIV-infected women.

Quantitative hepatic phosphorus-31 magnetic resonance spectroscopy in compensated and decompensated cirrhosis

2004 ◽  
Vol 287 (2) ◽  
pp. G379-G384 ◽  
Author(s):  
I. R. Corbin ◽  
L. N. Ryner ◽  
H. Singh ◽  
G. Y. Minuk
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Phospholipid Metabolism ◽  
Whole Body ◽  
Decompensated Cirrhosis ◽  
Resonance Spectroscopy ◽  
Healthy Controls ◽  
Hepatic Decompensation ◽  
Noninvasive Technique ◽  
Compensated Cirrhosis

Few studies have examined the physiological/biochemical status of hepatocytes in patients with compensated and decompensated cirrhosis in situ. Phosphorus-31 magnetic resonance spectroscopy (31P MRS) is a noninvasive technique that permits direct assessments of tissue bioenergetics and phospholipid metabolism. Quantitative 31P MRS was employed to document differences in the hepatic metabolite concentrations among patients with compensated and decompensated cirrhosis as well as healthy controls. All MRS examinations were performed on a 1.5-T General Electric Signa whole body scanner. The concentration of hepatic phosphorylated metabolites among patients with compensated cirrhosis ( n = 7) was similar to that among healthy controls ( n = 8). However, patients with decompensated cirrhosis ( n = 6) had significantly lower levels of hepatic ATP compared with patients with compensated cirrhosis and healthy controls ( P < 0.02 and P < 0.009, respectively) and a higher phosphomonoester/phosphodiester ratio than controls ( P < 0.003). The results of this study indicate that metabolic disturbances in hepatic energy and phospholipid metabolism exist in patients with decompensated cirrhosis that are not present in patients with compensated cirrhosis or healthy controls. These findings provide new insights into the pathophysiology of hepatic decompensation.

Volume Selective NMR Spectroscopy by Coded Slice Excitation (CODEX)

1988 ◽  
Vol 43 (11) ◽  
pp. 909-913 ◽  
Author(s):  
W. I. Jung ◽  
O. Lutz
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Volume Of Interest ◽  
The Stability

Abstract A method for volume selective nuclear magnetic resonance spectroscopy has been developed and implemented on an 1.5 T whole body imager for in vivo investigations. Four single experiments produce different magnetizations in the same slice, and a special subtract scheme yields the signal of only the volume of interest, which is accurately defined. The resolution of the spectra and the stability of the method have been verified with a water phantom containing acetone, ethanol, methanol, and oil vessels.

scholarly journals Body Composition Changes with Long-term Pegvisomant Therapy of Acromegaly

2021 ◽  
Vol 5 (3) ◽  
Author(s):  
Adriana P Kuker ◽  
Wei Shen ◽  
Zhezhen Jin ◽  
Simran Singh ◽  
Jun Chen ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Composition ◽  
Magnetic Resonance ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Model Assessment ◽  
Long Term Effects ◽  
Body Composition Change ◽  
Active Acromegaly

Abstract Context In active acromegaly, the lipolytic and insulin antagonistic effects of growth hormone (GH) excess alter adipose tissue (AT) deposition, reduce body fat, and increase insulin resistance. This pattern reverses with surgical therapy. Pegvisomant treats acromegaly by blocking GH receptor (GHR) signal transduction and lowering insulin-like growth factor 1 (IGF-1) levels. The long-term effects of GHR antagonist treatment of acromegaly on body composition have not been studied. Methods We prospectively studied 21 patients with active acromegaly who were starting pegvisomant. Body composition was examined by whole body magnetic resonance imaging, proton magnetic resonance spectroscopy of liver and muscle and dual-energy x-ray absorptiometry, and endocrine and metabolic markers were measured before and serially during 1.0 to 13.4 years of pegvisomant therapy. The data of patients with acromegaly were compared with predicted and to matched controls. Results Mass of visceral AT (VAT) increased to a peak of 187% (1.56-229%) (P &lt; .001) and subcutaneous AT (SAT) to 109% (–17% to 57%) (P = .04) of baseline. These remained persistently and stably increased, but did not differ from predicted during long-term pegvisomant therapy. Intrahepatic lipid rose from 1.75% to 3.04 % (P = .04). Although lean tissue mass decreased significantly, skeletal muscle (SM) did not change. IGF-1 levels normalized, and homeostasis model assessment insulin resistance and HbA1C were lowered. Conclusion Long-term pegvisomant therapy is accompanied by increases in VAT and SAT mass that do not differ from predicted, stable SM mass and improvements in glucose metabolism. Long-term pegvisomant therapy does not produce a GH deficiency-like pattern of body composition change.

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