1. Enhanced spectral resolution for correlated spectroscopic imaging using inner-product and covariance transform: a pilot analysis of metabolites and lipids in breast cancer in vivo.
- Author
-
Joy A and Thomas MA
- Subjects
- Humans, Female, Magnetic Resonance Spectroscopy methods, Echo-Planar Imaging methods, Fourier Analysis, Lipids, Breast Neoplasms diagnostic imaging
- Abstract
Acquisition duration of correlated spectroscopy in vivo can be longer due to a large number of t
1 increments along the indirect (F1 ) dimension. Limited number of t1 increments on the other hand leads to poor spectral resolution along F1 . Covariance transformation (CT) instead of Fourier transform along t1 is an alternative way of increasing the resolution of the 2D COSY spectrum. Prospectively undersampled five-dimensional echo-planar correlated spectroscopic imaging (EP-COSI) data from ten malignant patients and ten healthy women were acquired and reconstructed using compressed sensing. The COSY spectrum at each voxel location was then generated using FFT, CT and a variant of CT called Inner Product (IP). Metabolite and lipid ratios were computed with respect to water from unsuppressed one-dimensional spectrum. The effects of t1 -ridging artifacts commonly seen with FFT were not observed with CT/IP. Statistically significant differences were observed in the fat cross peaks measured with CT/IP/FFT. Spectral resolution was increased ~ 8.5 times (~ 19.53 Hz in FFT, ~ 2.32 Hz in CT/IP) without affecting the spectral width along F1 was possible with CT/IP. CT and IP enabled substantially increased F1 resolution effectively with significant gain in scan time and reliable measure of unsaturation index as a biomarker for malignant breast cancer., (© 2023. Springer Nature Limited.)- Published
- 2023
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