(31)P MR Spectroscopic Measurement of Intracellular pH in Normal Human Hearts.
10.3348/jkrs.2002.46.5.455
- Author:
Jae Hyun KWON
1
;
Hui Joong LEE
;
Yong Min JANG
;
Don Sik YU
;
Tae Kyun JUNG
;
Tae Byum SHIN
;
Kyung Soo BAE
;
Sung Won YOUN
;
Hye Jung KIM
;
Sung Hun KIM
;
Yong Joo KIM
;
Duck Sik KANG
Author Information
1. Department of Diagnostic Radiology, School of Medicine, Kyungpook National University. antiwto@hanmil.net
- Publication Type:Original Article
- Keywords:
Heart, MR spectroscopy;
Heart, MR
- MeSH:
Adenosine Triphosphate;
Healthy Volunteers;
Heart Diseases;
Heart*;
Humans*;
Hydrogen-Ion Concentration*;
Metabolism;
Myocardium;
Polymerase Chain Reaction;
Protons;
Reading
- From:Journal of the Korean Radiological Society
2002;46(5):455-460
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: To assess the usefulness of intracellular pH (pHi), calculated by determining the shift of a high-energy metabolite such as inorganic phosphate (Pi) or gamma-ATP after performing MRS with ECG-gated two-dimensional 31P CSI (chemical shift imaging), as a parameter for the overall state of the intracellular milieu. MATERIALS AND METHODS: Proton decoupled 31P CSI was performed on a 1.5-T scanner using a (1)H-(31)P dual-tuned surface coil. Cardiac MRS data were obtained from eight normal volunteers aged 24-32 years with no history of heart disease. From the spectra obtained from several regions of the heart, peak position and peak area were estimated. The metabolic ratios of alpha-, beta-, gamma-ATP, PCr, Pi, phosphodiester and diphosphoglycerate were calculated, and pHi was estimated from the chemical shift of Pi and gamma-ATP resonance. We then compared the data for the anterior myocardium with those previously published. RESULTS: The major phosphorous metabolites identified in these human hearts were as follows: PCr, at -0.1 to +0.1 ppm; three phosphate peaks from ATP, with a chemical shift centered at about -2.7 ppm (gamma-ATP), -7.8 ppm (alpha-ATP), and -16.3 ppm (beta-ATP); and phosphodiester (PDE) at 2-3 ppm, inorganic phosphate (Pi) at 4.5-5.4 ppm, and diphosphoglycerate (DPG) at 5.4-6.3 ppm. The PCr/beta-ATP ratio was 2.20+/-0.17 and the PDE/beta-ATP ratio, 1.04+/-0.09. pHi readings were 7.31+/-0.23 (calculated by the shift of Pi) and 6.81+/-0.20 (calculated by the shift of gamma-ATP). Pi/PCR was 0.539, a ratio higher than that mentioned in previously published reports. CONCLUSION: The measurement of intracelluar metabolism was affected by various kinds of factors. We believe, however, that pHi readings indicate the overall state of the cardiac intracelluar milieu. An unexpected pHi readings, seen at MRS, may reflect errors in the MR procedure itself and, or in the alanytical method.
