Cerebral diffusion tensor imaging and in vivo proton magnetic resonance spectroscopy in patients with fulminant hepatic failure.
OBJECTIVE
Cerebral edema is a major complication in patients with fulminant hepatic failure (FHF). The aim of this study was to evaluate the metabolite alterations and cerebral edema in patients with FHF using in vivo proton magnetic resonance spectroscopy (MRS) and diffusion tensor imaging, and to look for its reversibility in survivors.


METHODS
Ten FHF patients along with 10 controls were studied. Five of the 10 patients who recovered had a repeat imaging after three weeks. N-acetylaspartate, choline (Cho), glutamine (Gln), glutamine/glutamate (Glx), and myoinositol ratios were calculated with respect to creatine (Cr). Mean diffusivity (MD) and fractional anisotropy (FA) were calculated in different brain regions.


RESULTS
Patients exhibited significantly increased Gln/Cr and Glx/Cr, and reduced Cho/Cr ratios, compared to controls. In the follow-up study, all metabolite ratios were normalized except Glx/Cr. Significantly decreased Cho/Cr were observed in deceased patients compared to controls. In patients, significantly decreased MD and FA values were observed in most topographical locations of the brain compared to controls. MD and FA values showed insignificant increase in the follow-up study compared to their first study.


CONCLUSIONS
We conclude that the Cho/Cr ratio appears to be an in vivo marker of prognosis in FHF. Decreased MD values suggest predominant cytotoxic edema may be present. Persistence of imaging and MRS abnormalities at three weeks' clinical recovery suggests that metabolic recovery may take longer than clinical recovery in FHF patients.
Saksena
Sona
S
Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
Rai
Vijan
V
Saraswat
Vivek Anand
VA
Rathore
Ramkishore Singh
RS
Purwar
Ankur
A
Kumar
Manoj
M
Thomas
M Albert
MA
Gupta
Rakesh Kumar
RK
D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D002794:Choline / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006501:Hepatic Encephalopathy / Q000378:metabolism / Q000401:mortality / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007294:Inositol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D011379:Prognosis; D011522:Protons; D013997:Time Factors
D015415:Biomarkers; D011522:Protons; D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline