- Poster presentation
- Open Access
Development and validation of a short 31P cardiac magnetic resonance spectroscopy protocol
© Dass et al; licensee BioMed Central Ltd. 2010
- Published: 21 January 2010
- Cardiac Magnetic Resonance
- High Energy Phosphate
- Nuclear Overhauser Enhancement
- Routine Clinical Assessment
- Severe Cardiac Disease
Cardiac 31P-MRS is the only non-invasive in vivo technique for the determination of cardiac high energy phosphate metabolism. Changes in cardiac phosphocreatine to adenosine triphosphate ratios (PCr/ATP) occur in common cardiac pathologies and have diagnostic, prognostic and therapeutic utility. However, long acquisition times (20 minutes or more, depending on heart rate) required to achieve sufficient signal to noise ratios for reliable interpretation have limited the clinical utility of 31P-MRS studies in patients with severe cardiac disease.
We have developed an 8 minute 31P-MRS protocol and demonstrate the validity of this 'short' acquisition by comparison with a 'long' (at least 20 minutes) method of published reproducibility (Tyler, NMR Biomed:2008).
To design a robust, 'short' cardiac 31P-magnetic resonance spectroscopy (31P- MRS) protocol which facilitates acquisition within a clinically acceptable timeframe.
This 'short' protocol essentially incorporates a larger voxel (93 mls compared to 39 mls for 'long' protocol) but eliminates extra myocardial contamination by:
• active suppression of chest wall muscle and liver signals,
• raw data acquisition weighted to reduce contamination arising from outside the nominal voxel.
The accuracy of the data and its interpretation is improved by:
• optimised radio frequency (RF) pulse,
• flip angle calibration (at voxel of interest) used during post-processing to calculate and correct for subject variation to coil loading.
• calibrated signal enhancement (Nuclear Overhauser Enhancement (NOE)),
• rapid repetition time (with calibrated saturation correction).
22 healthy volunteers (age 42 ± 16.5; 13 males, 9 females), were scanned (3 T Siemens Trio) with both the 'long' and 'short' acquisitions.
Selected acquisition properties of compred protocols
Control (long, 20 min) protocol
Short (8 min) protocol
3D CSI Matric size
16 × 16 × 16
16 × 8 × 8
Field of view
240 × 240 × 240 mm
240 × 240 × 240 mm
No, TR 720 ms
>+ = 20 mins
Chest wall muscle saturation
RF saturation, NOE and blood correction factors applied
Subject specific flip angle map acquired
We have developed a novel 'short' cardiac 31P-MRS protocol of high data quality. This protocol allows cardiac spectroscopy to be measured in patients who are often intolerant of long acquisition times, such as those with severe cardiac disease and children. Hence this work provides a useful tool for the routine clinical assessment of cardiac 31P-MRS.
This article is published under license to BioMed Central Ltd.