ABSTRACT
PURPOSE: This study aims to investigate hippocampal subfield volumes in patients with hippocampal sclerosis (HS) without visually detectable MRI abnormalities and to determine the diagnostic accuracy using hippocampal subfield volumes. MATERIALS AND METHODS: We examined 46 patients with unilateral HS who had a histopathological diagnosis, and 54 controls. The patients were divided into two groups; visually detectable HS (n = 26) and undetectable HS (n = 20) on MRI. The volumes of hippocampal subfield using FreeSurfer were compared among the three groups. Diagnostic accuracy was calculated as the AUC of ROC using cutoff values for each individual subfield. RESULTS: Compared with the controls, visually detectable HS showed significantly reduced volumes of all the hippocampal subfields and entire hippocampus, whereas visually undetectable HS showed significant atrophy only in the CA3 and hippocampus-amygdala-transition-area. To diagnose visually undetectable HS, the CA3 volumes had AUC of 0.719, which was higher than AUC of 0.614 based on the entire hippocampal volumes. CONCLUSION: Visually undetectable HS demonstrated volume reductions in the CA3. Further, the CA3 volumes was more useful to diagnose visually undetectable HS compared with the entire hippocampal volumes.
Subject(s)
Epilepsy, Temporal Lobe/pathology , Hippocampus/diagnostic imaging , Hippocampus/pathology , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Adult , Atrophy/pathology , Epilepsy, Temporal Lobe/diagnostic imaging , Female , Humans , Male , Organ Size , Reproducibility of Results , Sclerosis/pathologyABSTRACT
PURPOSE: To assess atrophy differences among brain regions and time-dependent changes after whole-brain radiation therapy (WBRT). MATERIALS AND METHODS: Twenty patients with lung cancer who underwent both WBRT and chemotherapy (WBRT group) and 18 patients with lung cancer who underwent only chemotherapy (control group) were recruited. Three-dimensional T1WI were analyzed to calculate volume reduction ratio after WBRT in various brain structures. The volume reduction ratio of the hippocampus was compared among following 3 periods: 0-3, 4-7, and 8-11 months after WBRT. RESULTS: The volume reduction ratio of the hippocampus was significantly higher in the WBRT group than in the control group (p < 0.05). In WBRT group, the volume reduction ratio of the hippocampus was significantly higher than that of the cortex and white matter (p < 0.05). There were significant differences in the volume reduction ratio between of 0-3 months and that of 4-7 months (p = 0.02) and between 4-7 months and that of 8-11 months (p = 0.01). CONCLUSION: The hippocampus is more vulnerable to the radiation compared with other brain regions and may become atrophic even in the early stage after WBRT.
