Accurate phosphorus metabolite images of the human heart by 3D acquisition-weighted CSI

• Published in: Magnetic resonance in medicine 2001-05, Vol.45 (5), p.817-826
• Main Authors: Pohmann, Rolf, von Kienlin, Markus
• Format: Article
• Language: English
• Subjects: acquisition weighting; Adenosine Triphosphate - metabolism; Biological and medical sciences; cardiac 31P spectroscopy; Cardiovascular system; chemical shift imaging; high-energy phosphates; Humans; Imaging, Three-Dimensional; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Spectroscopy - methods; Male; Medical sciences; Miscellaneous. Technology; Myocardium - metabolism; Phosphorus - metabolism; Phosphorus Isotopes; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Signal Processing, Computer-Assisted; spatial resolution
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.1110

Fourier imaging modalities suffer from significant signal contamination between adjacent voxels, especially when the spatial resolution is comparable to the size of the anatomical structures. This contamination can be positive or negative, depending on the spatial response function and the geometry of the object. Such a situation arises in human cardiac 31P chemical shift imaging (CSI). Acquisition‐weighted CSI reduces this contamination substantially, which is demonstrated by comparing conventional CSI to Hanning‐weighted 3D 31P‐CSI experiments in 13 healthy volunteers at 2 T. The nominal spatial resolution and the total number of scans were identical for both experiments. The improved spatial response function of the acquisition‐weighted experiment led to a significantly (P < 0.0001) higher myocardial PCr/ATP ratio (2.05 ± 0.31, mean ± SD, N = 33, corrected for saturation and blood contribution) compared to the conventional CSI experiment (1.60 ± 0.46). This is explained by the absence of negative contamination from skeletal muscle, which also resulted in an increase of the observed SNR (from 5.4 ± 1.4 to 7.2 ± 1.4 for ATP). With acquisition‐weighted CSI, metabolic images with a nominal resolution of 16 ml could be obtained in a measurement time of 30 min. After correction for the inhomogeneous B1 field of the surface coil, these images show uniform ATP distribution in the entire myocardium, including the posterior wall. Magn Reson Med 45:817–826, 2001. © 2001 Wiley‐Liss, Inc.