Secondary MRI-findings, volumetric and spectroscopic measurements in mesial temporal sclerosis: a multivariate discriminant analysis.
BACKGROUND
Primary- and secondary MR findings, volumetric measurements and MR spectroscopy data of each hippocampus represent more a dozen of variables that radiologists should consider in a quantitative MR report of temporal lobe epilepsy (TLE). There is a paucity of data about the significance of secondary MR findings simultaneously evaluated with volumetry and MR spectroscopy. We analyzed the influence of qualitative-secondary MR findings simultaneously with quantitative (volumetry and spectroscopy) data in MRI positive- and negative patients with mesial temporal sclerosis (MTS).


METHODS
Analytic and transversal study of 59 patients with TLE and suspiciousness of MTS. 13 variables were analyzed for each hippocampus: age, gender, cerebral hemisphere, temporal lobe atrophy, choroidal fissure dilatation, mamillary body atrophy, collateral white matter atrophy, fornix asymmetry; Naa/Cr, Cho/Cr, mI/Cr, Naa/(Cr+Cho); and hippocampus volume (mm3). Multivariate discriminant analysis (DA) was performed with the aim to identify specific morphologic and metabolic attributes in hippocampi with and without MTS.


RESULTS
Discriminant function significantly differentiated the hippocampi with- and without MTS (Wilks' λ = 0.211, χ2 (11) = 116.072, p = < .001. The model explained 79.03% of the variation in the grouping variable. The pooled within-groups correlations showed the highest influence of discriminating function for the secondary MR findings over metabolite indices and hippocampal volumes, the overall predictive accuracy was 93.9%.


CONCLUSIONS
Due of the large number of variables (qualitative and quantitative) to which a radiologist is exposed in a conventional hippocampal MR-report, such evaluation might benefit from the use of predictive models generated by unconventional statistical methods, such as DA.
Magnetic Resonance Unit, Medica Sur Clinic & Foundation, Mexico city, Mexico.
Maria Luisa
ML
Lopez-Acevedo
Manuel
M
Martinez-Lopez
Rafael
R
Favila
Ernesto
E
Roldan-Valadez
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016002:Discriminant Analysis; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009929:Organ Size; D012189:Retrospective Studies; D012598:Sclerosis; D013702:Temporal Lobe / Q000473:pathology*