Table 2.
Summary of the Main Results Published to Date Now Using Different In Vivo MRI/MRS Techniques in Chronic HE Animal Models.
| Animal model | Subjects (n) | Magnetic Field (B0) | Method | Brain region | Type of measurement | Findings |
Comments | Ref | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Edema | Type of edema Cell type | Other | ||||||||
|
BDL rats Sham rats |
8 6 |
7T |
1H MRS, PRESS, TE=12ms 7 metabolites quantified using LCModel, absolute quantification using water as internal reference DTI, 20 directions and 4 b-values (0-1000 s/mm2) |
6.5x6.5x6.5mm3 - No brain region specific VC, SC, MC, Hip, Tha, HypoT, Str, NC |
In vivo Longitudinal @ 4, 5, 6 weeks post-BDL |
Indirect indication In LPS – indication of intra and extra cellular edema supported by no changes in ADC |
N/A |
↑Gln ↓Glu, tCho, tCr, NAA and Ins No change in Lac -No difference in ADC values between BDL and sham operated rats and neither in water content using gravimetry (Table 1) |
Statistical changes are between-group over the entire time course with LPS injections as last time point and not by individual time points LPS injection ↑water content in brain (gravimetry-Table 1) |
25 |
| BDL rats | 7 | 9.4T |
1H MRS, SPECIAL, TE=2.8ms 18 metabolites quantified using LCModel, absolute quantification using water as internal reference Changes post-BDL always compared to those before BDL (week 0) |
4x7.5x6.5mm3 - No brain region specific | In vivo – longitudinal @ 0, 4, 8 weeks post-BDL | Indirect indication |
N/A |
↑Gln and plasma NH4+ post-BDL ↓Ins, tCho @ 8 weeks post-BDL ↓Glu, Asp @ 8 weeks post-BDL ↑Sum of main brain organic osmolytes @ 8 weeks post-BDL |
Positive correlation between brain Gln and plasma NH4+ Brain Gln showed stronger correlations than plasma NH4+ with the rest of metabolites |
96 |
Abbreviations: visual cortex (VC), sensorimotor cortex (SC), motor cortex (MC), hippocampus (Hip), thalamus (Tha), hypothalamus (HypoT), striatum (Str), nucleus accumbens (NC), lactate (Lac), glutamine (Gln), taurine (Tau), inositol (Ins), glutamate (Glu), total choline (tCho), total creatine (tCr), N-Acetylaspartate (NAA), aspartate (Asp), lipopolysaccharide (LPS), bile duct ligation (BDL), diffusion tensor imaging (DTI), proton magnetic resonance spectroscopy (1H MRS), apparent diffusion coefficient (ADC), SPin ECho, full Intensity Acquired Localized (SPECIAL), point resolved spectroscopy (PRESS), echo time (TE). Authors personal comments are in italics in the comments row.