1. Dictionary learning compressed sensing reconstruction: pilot validation of accelerated echo planar J-resolved spectroscopic imaging in prostate cancer
- Author
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Joy, Ajin, Nagarajan, Rajakumar, Saucedo, Andres, Iqbal, Zohaib, Sarma, Manoj K, Wilson, Neil, Felker, Ely, Reiter, Robert E, Raman, Steven S, and Thomas, M Albert
- Subjects
Biomedical and Clinical Sciences ,Engineering ,Information and Computing Sciences ,Communications Engineering ,Oncology and Carcinogenesis ,Computer Vision and Multimedia Computation ,Bioengineering ,Cancer ,Clinical Research ,Urologic Diseases ,Prostate Cancer ,Biomedical Imaging ,Choline ,Echo-Planar Imaging ,Humans ,Imaging ,Three-Dimensional ,Magnetic Resonance Imaging ,Magnetic Resonance Spectroscopy ,Male ,Prostatic Neoplasms ,Echo planar J-resolved spectroscopic imaging ,Prostate cancer ,Compressed sensing ,Citrate ,Myo-inositol ,Nuclear Medicine & Medical Imaging - Abstract
ObjectivesThis study aimed at developing dictionary learning (DL) based compressed sensing (CS) reconstruction for randomly undersampled five-dimensional (5D) MR Spectroscopic Imaging (3D spatial + 2D spectral) data acquired in prostate cancer patients and healthy controls, and test its feasibility at 8x and 12x undersampling factors.Materials and methodsProspectively undersampled 5D echo-planar J-resolved spectroscopic imaging (EP-JRESI) data were acquired in nine prostate cancer (PCa) patients and three healthy males. The 5D EP-JRESI data were reconstructed using DL and compared with gradient sparsity-based Total Variation (TV) and Perona-Malik (PM) methods. A hybrid reconstruction technique, Dictionary Learning-Total Variation (DLTV), was also designed to further improve the quality of reconstructed spectra.ResultsThe CS reconstruction of prospectively undersampled (8x and 12x) 5D EP-JRESI data acquired in prostate cancer and healthy subjects were performed using DL, DLTV, TV and PM. It is evident that the hybrid DLTV method can unambiguously resolve 2D J-resolved peaks including myo-inositol, citrate, creatine, spermine and choline.ConclusionImproved reconstruction of the accelerated 5D EP-JRESI data was observed using the hybrid DLTV. Accelerated acquisition of in vivo 5D data with as low as 8.33% samples (12x) corresponds to a total scan time of 14 min as opposed to a fully sampled scan that needs a total duration of 2.4 h (TR = 1.2 s, 32 [Formula: see text]×16 [Formula: see text]×8 [Formula: see text], 512 [Formula: see text] and 64 [Formula: see text]).
- Published
- 2022