Combined MRI and MRS in prostate cancer: improvement of spectral quality by susceptibility matching
| Autor: | M. Vogel, A. F. Heuck, J. Scheidler, P. Gross |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
In vivo magnetic resonance spectroscopy
Male Magnetic Resonance Spectroscopy Image quality Time saving Sensitivity and Specificity chemistry.chemical_compound Prostate cancer Nuclear magnetic resonance Image Interpretation Computer-Assisted Biomarkers Tumor Medicine Humans Radiology Nuclear Medicine and imaging Perflubron business.industry Prostatic Neoplasms Reproducibility of Results medicine.disease Magnetic Resonance Imaging Full width at half maximum chemistry Mr spectroscopic imaging business Nuclear medicine Artifacts Algorithms Endorectal coil |
| Zdroj: | RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin. 181(6) |
| ISSN: | 1438-9010 |
| Popis: | PURPOSE: Local magnetic field inhomogeneity caused by susceptibility artifacts due to air in the endorectal coil substantially degrades the quality of 3D MR spectroscopic imaging (3D-MRSI). Perflubron (PFB) has magnetic susceptibility similar to that of human tissue. We prospectively assessed the effect of susceptibility matching using PFB on in vivo prostate 1 H-3D-MRSI. MATERIALS AND METHODS: Ninety-one consecutive patients referred for 3D-MRSI were examined using air and PFB as the filling agent for endorectal coils at 1.5T with an identically placed PRESS box and sat bands. Solely auto-shim without additional manual shimming was used. The full width at half maximum (FWHM) of the water peak was statistically compared with a paired t-test. The spectral quality was visually evaluated for the definition of metabolite peaks and for the citrate peak split (duplet). The MR image quality was rated on a five-point scale. RESULTS: FWHM was significantly less (p < 0.001) using PFB (mean 9.0 ± 3.3, range 3 - 20) than air (mean 14.9 ± 4.2, range 6 - 26) in 85 / 91 patients (93 %). The spectral quality markedly improved using PFB and frequently the duplet of the citrate peak was able to be identified. Image quality ratings were similar (mean rating PFB 4.2, air 4.3 points). Omitting manual shimming led to a time savings of 4 min. per study. CONCLUSION: 3D-MRSI using PFB for susceptibility matching benefits from significantly better local field homogeneity, thus providing improved spectra quality. Combined with a substantial time savings in data acquisition, this may increase the clinical utilization of 3D-MRSI in patients with prostate cancer. |
| Databáze: | OpenAIRE |
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