276 research outputs found
Quantification of Volumetric Changes of Brain in Neurodegenerative Diseases Using Magnetic Resonance Imaging and Stereology
A Comparison of Automated Segmentation and Manual Tracing of Magnetic Resonance Imaging to Quantify Lateral Ventricle Volumes
Objective: Ventricular volume measurements have been proposed as a useful biomarker for several neurological diseases. The goal of this study was to compare the performance of 3 fully-automated tools, volBrain (http://volbrain.upv.es), ALVIN (Automatic Lateral Ventricle Delineation) (https://sites.google.com/site/mrilateralventricle/), and MRICloud (http://mricloud.org), with expert hand tracing to quantify lateral ventricle (LV) volume using magnetic resonance images. Materials and Methods: The sample comprised 24 healthy subjects (age: 25.1±5.7 years, all male). Volumes derived from each automated measurement were compared to hand tracing results performed by 2 specialists to assess the percent volume difference using the intraclass correlation coefficient (ICC), concordance correlation coefficient (CCC), Dice index value, and Bland-Altman analysis. Results: The ICC agreement of the Manual_1 and Manual_2 was very good (0.979), and there was no statistically significant difference (p>0.001). The volume difference of all methods was similar. The CCC with MRICloud and ALVIN was higher than that of volBrain. Bland-Altman plots indicated that the 3 automated methods demonstrated acceptable agreement. Conclusion: Compared with hand tracing, the LV volumes generated by MRICloud were more accurate than those of volBrain and ALVIN. LV volume values can provide valuable data related to the volumetric dependencies of the anatomical structures in various clinical conditions that can now be easily obtained using automated tools
Analysis of the Volumes of the Posterior Cranial Fossa, Cerebellum, and Herniated Tonsils Using the Stereological Methods in Patients with Chiari Type I Malformation
Objective. The aim of this study was to determine the posterior cranial fossa volume, cerebellar volume, and herniated tonsillar volume in patients with chiari type I malformation and control subjects using stereological methods. Material and Methods. These volumes were estimated retrospectively using the Cavalieri principle as a point-counting technique. We used magnetic resonance images taken from 25 control subjects and 30 patients with chiari type I malformation. Results. The posterior cranial fossa volume in patients with chiari type I malformation was significantly smaller than the volume in the control subjects (P < 0.05). In the chiari type I malformation group, the cerebellar volume was smaller than the control group, but this difference was not statistically significant (P > 0.05). In the chiari type I malformation group, the ratio of cerebellar volume to posterior cranial fossa volume was higher than in the control group. We also found a positive correlation between the posterior cranial fossa volume and cerebellar volume for each of the groups (r = 0.865, P < 0.001). The mean (±SD) herniated tonsillar volume and length were 0.89 ± 0.50 cm3 and 9.63 ± 3.37 mm in the chiari type I malformation group, respectively. Conclusion. This study has shown that posterior cranial fossa and cerebellum volumes can be measured by stereological methods, and the ratio of these measurements can contribute to the evaluation of chiari type I malformation cases
Comparison of Three Methods for the Estimation of Pineal Gland Volume Using Magnetic Resonance Imaging
Pineal gland is a very important neuroendocrine organ with many physiological functions such as regulating circadian rhythm. Radiologically, the pineal gland volume is clinically important because it is usually difficult to distinguish small pineal tumors via magnetic resonance imaging (MRI). Although many studies have estimated the pineal gland volume using different techniques, to the best of our knowledge, there has so far been no stereological work done on this subject. The objective of the current paper was to determine the pineal gland volume using stereological methods and by the region of interest (ROI) on MRI. In this paper, the pineal gland volumes were calculated in a total of 62 subjects (36 females, 26 males) who were free of any pineal lesions or tumors. The mean ± SD pineal gland volumes of the point-counting, planimetry, and ROI groups were 99.55 ± 51.34, 102.69 ± 40.39, and 104.33 ± 40.45 mm3, respectively. No significant difference was found among the methods of calculating pineal gland volume (P > 0.05). From these results, it can be concluded that each technique is an unbiased, efficient, and reliable method, ideally suitable for in vivo examination of MRI data for pineal gland volume estimation
Annular pancreas associated with nutcracker syndrome: A case report
The pancreas usually develops from the fusion of thedorsal and ventral pancreatic buds between the first 4-8weeks of embryonic life. Annular pancreas consists of aring of pancreatic tissue, which partially or completely surroundsthe descending portion of the duodenum. Annularpancreas is an uncommon congenital anomaly. The etiologyof this anomaly is still unknown. It has been associatedwith other congenital anomalies and various clinicalsymptoms. The nutcracker phenomenon is definedas compression of the left renal vein between the aortaand superior mesenteric artery. We report the case of a54-year-old patient who presented with a 15-day historyof nausea and vomiting associated with weight loss. Onmagnetic resonance cholangiopancreatography (MRCP)and computer tomography (CT) examination, an annularpancreas and nutcracker syndrome were diagnosed, respectively.In this study, we founded that the radiologicand clinical findings of associated annular pancreas withnutcracker syndrome may be of clinical importance forsurgical procedures.Key words: Annular pancreas, congenital anomaly, nutcrackerphenomenon, MRCP, C
Yenidoğan Kadavralarında Dalak Hacminin Ve Yüzey Alanının Stereolojik Olarak Hesaplanmas
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