31P MRS of myocardial inorganic phosphate using radiofrequency gradient echoes

J. R. Gober, G. G. Schwartz, Saul Schaefer, B. M. Massie, G. B. Matson, M. W. Weiner, G. S. Karczmar

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Determination of the chemical shift and integral of the myocardial intracellular inorganic phosphate (P(i)) resonance by 31P magnetic resonance spectroscopy (MRS) is often precluded due to a large overlapping signal from 2,3-diphosphoglycerate (2,3-DPG) from chamber and myocardial blood. This report demonstrates the use of radiofrequency (RF) magnetic field gradient echoes (RFGE) to eliminate signals from 2,3-DPG in flowing blood, while retaining signals from intracellular myocardial P(i), ATP, and phosphocreatine (PCr). The ECG-triggered 31P spectra were acquired from the myocardium of open chest pigs using a Philips Gyroscan 2-T magnetic resonance spectrometer. A 2.5-cm-diameter surface coil attached to the myocardium was used to provide the RF gradient as well as for excitation and detection of signals. Optimal performance of the RFGE pulse sequence was obtained when the RF gradient pulses were centered at peak diastole or peak systole. Under these conditions, 2,3-DPG signals were completely suppressed, and sensitivity was usually sufficient to allow detection of a well-resolved P(i) signal. Myocardial pH determined from RFGE experiments was 7.16 ± 0.10, and the ratio of the integrals of the P(i) and ATP resonances (P(i)/ATP) was 0.24. The mean signal-to-noise ratio (S/N) for PCr in control spectra acquired in 4 min was 19/1, while the mean S/N for PCr in RFGE-edited spectra acquired in 15 min was 11/1, demonstrating that the present implementation of the RFGE method results in significant loss in sensitivity. These experiments demonstrate that RFGE-editing allows accurate determination of the chemical shift and integral of the P(i) resonance in blood-perfused myocardium in situ.

Original languageEnglish (US)
Pages (from-to)171-183
Number of pages13
JournalMagnetic Resonance in Medicine
Volume20
Issue number2
StatePublished - 1991

Fingerprint

Magnetic Fields
Magnetic Resonance Spectroscopy
Phosphates
2,3-Diphosphoglycerate
Phosphocreatine
Myocardium
Adenosine Triphosphate
Diastole
Systole
Signal-To-Noise Ratio
Electrocardiography
Swine
Thorax

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Gober, J. R., Schwartz, G. G., Schaefer, S., Massie, B. M., Matson, G. B., Weiner, M. W., & Karczmar, G. S. (1991). 31P MRS of myocardial inorganic phosphate using radiofrequency gradient echoes. Magnetic Resonance in Medicine, 20(2), 171-183.

31P MRS of myocardial inorganic phosphate using radiofrequency gradient echoes. / Gober, J. R.; Schwartz, G. G.; Schaefer, Saul; Massie, B. M.; Matson, G. B.; Weiner, M. W.; Karczmar, G. S.

In: Magnetic Resonance in Medicine, Vol. 20, No. 2, 1991, p. 171-183.

Research output: Contribution to journalArticle

Gober, JR, Schwartz, GG, Schaefer, S, Massie, BM, Matson, GB, Weiner, MW & Karczmar, GS 1991, '31P MRS of myocardial inorganic phosphate using radiofrequency gradient echoes', Magnetic Resonance in Medicine, vol. 20, no. 2, pp. 171-183.
Gober JR, Schwartz GG, Schaefer S, Massie BM, Matson GB, Weiner MW et al. 31P MRS of myocardial inorganic phosphate using radiofrequency gradient echoes. Magnetic Resonance in Medicine. 1991;20(2):171-183.
Gober, J. R. ; Schwartz, G. G. ; Schaefer, Saul ; Massie, B. M. ; Matson, G. B. ; Weiner, M. W. ; Karczmar, G. S. / 31P MRS of myocardial inorganic phosphate using radiofrequency gradient echoes. In: Magnetic Resonance in Medicine. 1991 ; Vol. 20, No. 2. pp. 171-183.
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