 Hello everyone, this is Dr. Divajat Kumar, 2nd year radiology resident from Dr. D. Y. Patil Medical College Pimpri Pune. I'll be presenting my paper on volumetric analysis of hippocampal lobe in pediatric patients complaining of partial seizures but without any abnormal MR signal intensity. I'll be doing this under the guidance of Dr. Krishna Tejasar. The study is partly based on a previous study, volumetric assessment of hippocampus in structural MRI. There are no conflicts of interest, there was no financial support and sponsorship associated with this study. The only aim of this study is to determine the volume of hippocampal lobe and its diagnostic significance in patients with clinical history but having no abnormal signal intensity on MR images. The study is done in concordance with asymptomatic controls who are having normal hippocampal volume. Coming to anatomy of hippocampus on MRI, hippocampus comprises of head, body and tail. The hippocampal complex is located in the medial aspect of the temporal lobe posterior to the amygdala. On MRI, hippocampal head is seen in the same coronal plane as the interbedicular system. The body of the hippocampus is seen at the level of midbrain. It lies inferior to the coroidal fissure and is separated from the parahippocampal gyrus by the hippocampal fissure. The tail of hippocampus is located at or behind the midbrain where it is seen adjacent to the crura of the furnaces. Volumetric significance of hippocampus on 3T MRI, hippocampus plays a significant role in secondary memory and its volume is significantly affected in patients presenting with seizures especially in pediatric age group. Volumetry of the hippocampus is often regarded as the best method for quantifying MR detectable pathologies in hippocampus. Volumetric analysis is more important in conditions where only the size of hippocampus has decreased but there is no abnormal signal intensity. In MR images obtained from 3 Tesla scanners, it is more possible to segment the hippocampus. It is a retrospective study. 30 children in the age group of 5 to 15 years were selected. Hippocampal volume was measured using a 3T scanner. Duration of study was from September 2020 to November 2021. Coming to the anatomical principles, our segmentation protocol uses hippocampal uncle fissure as the medial border, which means that only the part of subiculum contiguous with the hippocampus is included. The segmentation consists of two parts, internal landmark setting done by point-wise cross-setting in the societal view of the reformatted coronal images. Segmentation of the hippocampus in the coronal series done by continuous pen drawing and point-wise sampling. The study characteristics feature that out of 30 children in the age group of 5 to 15 years were included in the study. 15 children with the clinical history of partial seizures but not having any abnormal signal intensity on MR images are considered as subjects for the study. The rest 15 are asymptomatic children who are considered as controls for the study for determining the normal volumetric range. Informed consent was obtained from respective parents or guardians of the participating children. The subjects are scanned in 3T MR and serial MRI of brain and temporal lobe were performed. Oblique coronal sections perpendicular to the axis of temporal lobe were done with 2.5 mm slice thickness. T1, T2 flare and FSPGR sequences were done. Hippocampal volume are derived by manual quantification using volume-share algorithms. Now hippocampal segmentation was done on coronal slices scanned perpendicularly to the hippocampal principal axis and the following scan parameters was used. Coming to segmentation, segmentation of the hippocampus starts in the body which is the easier part and it ends in the more difficult part that is head and tail. Starting in the first slice of the body, posterior to the hippocampal head, the segmentation proceed to the last slice of the tail. Then the segmentation continues with a glance of the starting slice in the body from the first slice of the hippocampal head to the most anterior slide. Here we see that the landmarks set in the reformatted sagittal slice of the hippocampal region. The yellow line in the first image shows the position of the coronal slice in A2. The red crosses are used for anterior and posterior limits and the green crosses are used for other limits. Green landmarks are then transformed into coronal view to guide the segmentation in the anterior hippocampal head. 3D visualization. After segmenting the whole hippocampus, it is 3D visualized to check for deviations from curvature expectations. Hippocampus should have a smooth curvature on lateral side at the border between the hippocampus and the lateral ventricle. On the inferior side, the border between the hippocampus and the white matter of the parahippocampal gyrus should also be smooth. Discontinuities from the expectations regarding curvature could be a result of patient movements that result in every second slice displacement and the radar must be open of this possibility. Unexpected discontinuities in curvature that are most probably are the results of such obvious errors can then be adjusted for in the segmentations. Using the external landmarks, the full volumes were cropped in order to allow a better comparison with the earlier volumes found using external landmarks. The correlation between the cropped volume and the old volume were 0.87 for the right hippocampus and 0.91 for the left. The correlation of the remaining anterior or posterior volumes of the whole hippocampus with each other and with old volumes using external landmarks were however all weakly negative. The number of hippocampus slices anterior to the anterior landmark and the number of slices posterior to the posterior landmark were also negatively correlated with each other. So this was the result that was obtained after performing the sequences on all 15 control and cases. In the study, the normal range of the hippocampal volume is determined to be 2.6 plus minus 0.35 centimeter cube on the right side and 2.5 plus minus 0.35 centimeter cube on the left side. Of the 15 children with positive clinical history, 12 percent of patients have shown mean of right hippocampal volume 2 plus minus 0.35 cc and of the left hippocampal volume 2.1 plus minus 0.35 cc which is decreased in comparison to the control population. So the following conclusion was derived that volumetric analysis has found to be more sensitive with detection of volume loss in patients with no abnormal signal intensity and in concordance with visual perception, the volumetric range helps in accurate diagnosis of various conditions like mesial temporal lobe epilepsy, schizophrenia, fragile x-syndrome and post-traumatic stress disorder.