Two‐dimensional MR spectroscopy of minimal hepatic encephalopathy and neuropsychological correlates in vivo |
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Authors: | Aparna Singhal MD Rajakumar Nagarajan PhD Charles H. Hinkin MD Rajesh Kumar PhD James Sayre PhD Virginia Elderkin‐Thompson MD Amir Huda PhD Rakesh K. Gupta MD Steven‐Huy Han MD M. Albert Thomas PhD |
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Affiliation: | 1. Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA;2. Department of Psychiatry, David Geffen School of Medicine, University of California, Los Angeles, California, USA;3. VA Greater Los Angeles Healthcare System, Los Angeles, California, USA;4. Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California, USA;5. Department of Public Health‐Biostatistics David Geffen School of Medicine, University of California, Los Angeles, California, USA;6. Department of Physics, California State University, Fresno, California, USA;7. Department of Radiology, Sanjay Gandhi Post‐Graduate Institute of Medical Sciences, Lucknow, India;8. Department of Hepatology, David Geffen School of Medicine, University of California, Los Angeles, California, USA |
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Abstract: | Purpose: To evaluate regional cerebral metabolic and structural changes in patients with minimal hepatic encephalopathy (MHE) using two‐dimensional (2D) MR spectroscopy (MRS) and T ‐weighted MRI, to correlate the observed MR changes with neuropsychological (NP) test scores, and to compare the diagnostic accuracy of MRI, 2D MRS, and NP tests in discriminating between patients and healthy subjects. Materials and Methods: Thirty‐three MHE patients and 30 healthy controls were investigated. The 2D localized correlated spectroscopy (L‐COSY) was performed in the frontal and occipital brain on a 1.5 Tesla (T) MR scanner. The NP test battery included 15 tests, grouped into 6 cognitive domains. Globus pallidus signal intensities were calculated from T1‐weighted images. Results: The 2D MRS showed significant differences in ratios of the following metabolite(s) peaks with respect to creatine (Cr): decreased myo‐inositol (mI), choline (Ch), mICh, and increased (glutamate plus glutamine) (Glx) in patients compared with healthy subjects in both occipital and frontal lobes. Frontal lobe taurine also showed a decline in patients. The NP test results revealed declines in cognitive speed, motor function, executive function, and global cognitive status. Significant correlations were found between the altered metabolites and NP tests. Alteration in the mICh/Cr ratio was noted as a powerful discriminant between healthy subjects and the patients. Conclusion: The study demonstrates that relative metabolite levels determined by 2D MRS, in particular mICh/Cr, provide the best diagnostic prediction for MHE. The results suggest that depletions of myo‐inositol, choline and taurine with respect to creatine correlate with measures of neuropsychological impairment. J. Magn. Reson. Imaging 2010;32:35–43. © 2010 Wiley‐Liss, Inc. |
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Keywords: | MRI MRS COSY neuropsychological scores liver disease |
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