Comparison of manual and automatic methods of hippocampus segmentation

2011 ◽  
Vol 26 (S2) ◽  
pp. 914-914
Author(s):  
R. Barteček ◽  
N.E.M. van Haren ◽  
P.C.M.P. Koolschijn ◽  
H.E. Hulshoff Pol ◽  
R.S. Kahn
Keyword(s):  
Psychiatric Patients ◽  
Automatic Segmentation ◽  
Manual Segmentation ◽  
Subcortical Structures ◽  
Cronbach’S Alpha ◽  
Brain Scans ◽  
Cronbach's Alpha ◽  
Segmentation Methods ◽  
Automatic Methods ◽  
The Difference

IntroductionPsychiatric Patients show abnormalities in volumes of several subcortical structures. Recently wider usage of automated segmentation methods in research of these abnormalities based on MR images has become possible. However manual segmentation is still considered to be the gold standard.ObjectivesTo compare differences in hippocampus volumes between manual segmentation and 2 packages for automatic segmentation (FSL and FreeSurfer).AimTo explore the overlap and differences between different segmentation methods used for segmentation of subcortical structures.MethodsStructural MR brain scans were aquired from 98 subjects (53 schizophrenia patients, 45 controls). Volumes of left and right hippocampus were measured after manual, FreeSurfer and FSL segmentations. Differences between volumes from different methods were tested by the t-test (using R). In addition percent volume differences, Pearson correlations, Bland-Altman plots and Cronbach’s alpha were computed.ResultsBoth automatic methods yielded significantly larger hippocampal volumes than the manual segmentation. FreeSurfer volumes showed a higher correlation and lower percent volume difference with manual segmentation than FSL. Bland-Altman plots and Cronbach’s alpha showed only limited agreement between manual and both automatic methods.ConclusionsAlthough volumes acquired by FreeSurfer appeared to be more related to manual segmentation, clear superiority of either of automatic methods could not be demonstrated. Therefore, all three methods seem to measure other aspects of hippocampus volume. An useful approach would be to compare effect-size of the difference between patients and healthy controls using different segmentation methods. We are currently pursuing this in a larger sample.

scholarly journals Semi-Automatic Signature-Based Segmentation Method for Quantification of Neuromelanin in Substantia Nigra

2019 ◽  
Vol 9 (12) ◽  
pp. 335 ◽  
Author(s):  
Gašper Zupan ◽  
Dušan Šuput ◽  
Zvezdan Pirtošek ◽  
Andrej Vovk
Keyword(s):  
Substantia Nigra ◽  
Sensitivity And Specificity ◽  
Roc Analysis ◽  
Automatic Segmentation ◽  
High Sensitivity ◽  
Segmentation Method ◽  
Surface Sensitivity ◽  
Volume Sensitivity ◽  
Segmentation Methods ◽  
The Difference

In Parkinson’s disease (PD), there is a reduction of neuromelanin (NM) in the substantia nigra (SN). Manual quantification of the NM volume in the SN is unpractical and time-consuming; therefore, we aimed to quantify NM in the SN with a novel semi-automatic segmentation method. Twenty patients with PD and twelve healthy subjects (HC) were included in this study. T1-weighted spectral pre-saturation with inversion recovery (SPIR) images were acquired on a 3T scanner. Manual and semi-automatic atlas-free local statistics signature-based segmentations measured the surface and volume of SN, respectively. Midbrain volume (MV) was calculated to normalize the data. Receiver operating characteristic (ROC) analysis was performed to determine the sensitivity and specificity of both methods. PD patients had significantly lower SN mean surface (37.7 ± 8.0 vs. 56.9 ± 6.6 mm2) and volume (235.1 ± 45.4 vs. 382.9 ± 100.5 mm3) than HC. After normalization with MV, the difference remained significant. For surface, sensitivity and specificity were 91.7 and 95 percent, respectively. For volume, sensitivity and specificity were 91.7 and 90 percent, respectively. Manual and semi-automatic segmentation methods of the SN reliably distinguished between PD patients and HC. ROC analysis shows the high sensitivity and specificity of both methods.

Research on Automatic Segmentation Methods of Multi-Beam Waterjet Cutting Process Drawings

2011 ◽  
Vol 314-316 ◽  
pp. 1571-1575
Author(s):  
Hui Kang Yang ◽  
Dean Zhao ◽  
Jin Liang Guo ◽  
Jun Zhang ◽  
Bo Chen
Keyword(s):  
Automatic Segmentation ◽  
Cutting Process ◽  
Secondary Development ◽  
Manual Segmentation ◽  
Work Efficiency ◽  
Waterjet Cutting ◽  
Development Tool ◽  
Segmentation Methods ◽  
Low Efficiency

Currently, some manual segmentation problems exist in multi-beam waterjet cutting process drawings, such as low efficiency, incomplete segmentation and so on. In order to solve the problems, this paper designs a set of criteria for multi-beam cutting process and proposes the method of partition-classification trim, then uses the secondary development tool which is embedded in AutoCAD to program three user-defined commands, and these commands can partition the drawing by region, classify and trim the entities in the cutting process drawing. Through inputting the three simple commands on the command lines, it can realize automatic segmentation of cutting process drawings. Finally, the feasibility of this method is proved by a segmentation experiment. It can effectively solve the problems which exist in manual segmentation and greatly improve work efficiency.

scholarly journals Estudio descriptivo de la capacidad de emprendimiento de los alumnos del Instituto Tecnológico de Sonora

2019 ◽  
pp. 1-8
Author(s):  
Ramiro Arnoldo Buelna-Peñuñuri ◽  
María Elvira López-Parra
Keyword(s):  
Social Relation ◽  
Descriptive Study ◽  
Likert Scale ◽  
Cronbach’S Alpha ◽  
Cronbach's Alpha ◽  
Acceptable Range ◽  
Significant Difference ◽  
Integral Development ◽  
The Difference

The Instituto Tecnologico de Sonora (ITSON) is a university concerned about the integral development of its students, developing the capacity of entrepreneurship through its dimensions. The objective of this research was to identify the entrepreneurship capacity of the students through a descriptive study and difference of means, which allows the knowledge of the levels of perception in their dimensions. The participants were students enrolled in entrepreneurship and the instrument was applied to a sample of 40 students. The type of research was descriptive with the difference of means of each gender. The instrument was adapted from Mavila, Tinoco & Campos (2009) with a Likert scale that goes from 5 to 1 where 5 is never and 1 always. Cronbach's alpha was 0.908. Regarding the findings, in the dimensions it was observed that the highest perception with an average of 1.5000 corresponds to self-realization and the lowest one with 1.9958 to social relation, both in the acceptable range. Regarding the difference of means over gender, it was observed that there is no significant difference. It is concluded that the ITSON students perceive that they have a capacity for entrepreneurship.

scholarly journals A novel technique for olfactory bulb measurements

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243941
Author(s):  
Akshita Joshi ◽  
Divesh Thaploo ◽  
Xiaoguang Yan ◽  
Theresa Herrmann ◽  
Hudaa Alrahman Khabour ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Manual Segmentation ◽  
Cronbach’S Alpha ◽  
Volume Calculation ◽  
Cronbach's Alpha ◽  
Novel Technique ◽  
Observer Reliability ◽  
Frame Method ◽  
Established Technique

Background To introduce new ways to calculate OB volumes, checking their validity and comparing them to already established technique i.e. OB volumetric based on manual segmentation of OB boundaries. Methods Two approaches were used to calculate OB volumes (1) Manual Segmentation using planimetric manual contouring; (2) Box-frame method, calculating the parameters based on a box placed around the OB. Results We calculated OB volumes using both techniques and found comparable outcomes. High inter-observer reliability was found for volumes calculated by both observers. For manual segmentation, Cronbach’s alpha (α) was 0.91 and 0.93 for right and left OB volume, respectively, whereas for the box-frame method α was 0.94 and 0.90 for right and left OB, respectively. Conclusions The simple box-frame method of OB volume calculation appears reliable. Its results are comparable to an established technique.

scholarly journals Clinically feasible semi-automatic workflows for measuring metabolically active tumour volume in metastatic melanoma

2020 ◽  
Author(s):  
Joyce van Sluis ◽  
Ellen C. de Heer ◽  
Mayke Boellaard ◽  
Mathilde Jalving ◽  
Adrienne H. Brouwers ◽  
...  
Keyword(s):  
Overall Survival ◽  
Metastatic Melanoma ◽  
Pet Imaging ◽  
Fdg Pet ◽  
Tumour Volume ◽  
Imaging Biomarker ◽  
Manual Segmentation ◽  
Pet Ct ◽  
Segmentation Methods ◽  
Automatic Methods

Abstract Purpose Metabolically active tumour volume (MATV) is a potential quantitative positron emission tomography (PET) imaging biomarker in melanoma. Accumulating data indicate that low MATV may predict increased chance of response to immunotherapy and overall survival. However, metastatic melanoma can present with numerous (small) tumour lesions, making manual tumour segmentation time-consuming. The aim of this study was to evaluate multiple semi-automatic segmentation workflows to determine reliability and reproducibility of MATV measurements in patients with metastatic melanoma. Methods An existing cohort of 64 adult patients with histologically proven metastatic melanoma was used in this study. 18F-FDG PET/CT diagnostic baseline images were acquired using a European Association of Nuclear Medicine (EANM) Research Limited–accredited Siemens Biograph mCT PET/CT system (Siemens Healthineers, Knoxville, USA). PET data were analysed using manual, gradient-based segmentation and five different semi-automatic methods: three direct PET image–derived delineations (41MAX, A50P and SUV40) and two based on a majority-vote approach (MV2 and MV3), without and with (suffix ‘+’) manual lesion addition. Correlation between the different segmentation methods and their respective associations with overall survival was assessed. Results Correlation between the MATVs derived by the manual segmentation and semi-automated tumour segmentations ranged from R2 = 0.41 for A50P to R2 = 0.85 for SUV40+ and MV2+, respectively. Manual MATV segmentation did not differ significantly from the semi-automatic methods SUV40 (∆MATV mean ± SD 0.08 ± 0.60 mL, P = 0.303), SUV40+ (∆MATV − 0.10 ± 0.51 mL, P = 0.126), MV2+ (∆MATV − 0.09 ± 0.62 mL, P = 0.252) and MV3+ (∆MATV − 0.03 ± 0.55 mL, P = 0.615). Log-rank tests showed statistically significant overall survival differences between above and below median MATV patients for all segmentation methods with areas under the ROC curves of 0.806 for manual segmentation and between 0.756 [41MAX] and 0.807 [MV3+] for semi-automatic segmentations. Conclusions Simple and fast semi-automated FDG PET segmentation workflows yield accurate and reproducible MATV measurements that correlate well with manual segmentation in metastatic melanoma. The most readily applicable and user-friendly SUV40 method allows feasible MATV measurement in prospective multicentre studies required for validation of this potential PET imaging biomarker for clinical use.

scholarly journals Career Management Scale in Sports Organizations: A Validity and Reliability Study

2021 ◽  
Vol 15 (8) ◽  
pp. 2384-2389
Author(s):  
Erdem Eroğlu ◽  
Sultan Yavuz Eroğlu ◽  
Seydi Karakuş
Keyword(s):  
Factor Analysis ◽  
Confirmatory Factor Analysis ◽  
Correlation Analysis ◽  
Career Management ◽  
Validity And Reliability ◽  
Cronbach’S Alpha ◽  
Sports Organizations ◽  
Cronbach's Alpha ◽  
Confirmatory Factor ◽  
The Difference

Background: We wish to share the results of the scale we developed on the subject by evaluating the validity and reliability test of the career management scale in sports organizations. Methods: The study group consists of 317 participants working in provincial directorates of sports. The construct validity of the scale was tested by explanatory factor analysis and confirmatory factor analysis. Scale reliability was measured with Cronbach's Alpha and test-retest. The discrimination of the scale was tested based on the difference between the lower 27% and the upper 27%.A correlation analysis was carried out between scale factors. To calculate the reliability of 30 items in the career management scale, “Cronbach’s Alpha”, the internal consistency coefficient, was calculated. Results: The overall reliability of the scale was found to be very high as Alpha = 0.976. The analysis results showed that the fit statistics calculated with the confirmatory factor analysis fit well, and positive correlations were found between the dimensions of the scale and overall scores as a result of the correlation analysis (p <0.05). Keywords: Career, Career Management, Sports Management, Organizational Career Management, Individual Career Management

scholarly journals Regional SUV quantification in hybrid PET/MR, a comparison of two atlas-based automatic brain segmentation methods

2020 ◽  
Author(s):  
Weiwei Ruan ◽  
Xun Sun ◽  
Xuehan Hu ◽  
Fang Liu ◽  
Fan Hu ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Cerebral Metabolism ◽  
Automatic Segmentation ◽  
Group Analysis ◽  
Standardized Uptake Value ◽  
Emission Tomography ◽  
Manual Segmentation ◽  
Positron Emission ◽  
Segmentation Methods ◽  
Cerebellar Gray Matter

Abstract Background：Quantitative analysis of brain positron-emission tomography (PET) depends on structural segmentation, which can be time-consuming and operator-dependent when performed manually. Previous automatic segmentation usually registered subjects’ images onto an atlas template (defined as RSIAT here) for group analysis, which changed the individuals’ images and probably affected regional PET segmentation. In contrast, we could register atlas template to subjects’ images (RATSI), which created an individual atlas template and may be more accurate for PET segmentation. We segmented two representative brain areas in twenty Parkinson disease (PD) and eight multiple system atrophy (MSA) patients performed in hybrid positron-emission tomography/magnetic resonance imaging (PET/MR). The segmentation accuracy was evaluated using the Dice coefficient (DC) and Hausdorff distance (HD). and the standardized uptake value (SUV) measurements of these two automatic segmentation methods were compared, using manual segmentation as a reference. Results：The DC of RATSI increased and the HD decreased significantly (P < 0.05) compared with the RSIAT in PD, while the results of one-way analysis of variance (ANOVA) found no significant differences in the SUVmean and SUVmax among the two automatic and the manual segmentation methods. Further, RATSI was used to compare regional differences in cerebral metabolism pattern between PD and MSA patients. The SUVmean in the segmented cerebellar gray matter for the MSA group was significantly lower compared with the PD group (P<0.05), which is consistent with previous reports. Conclusion：The RATSI was more accurate for the caudate nucleus and putamen automatic segmentation, and can be used for regional PET analysis in hybrid PET/MR.

scholarly journals Automatic Segmentation of Mandible from Conventional Methods to Deep Learning—A Review

2021 ◽  
Vol 11 (7) ◽  
pp. 629
Author(s):  
Bingjiang Qiu ◽  
Hylke van der Wel ◽  
Joep Kraeima ◽  
Haye Hendrik Glas ◽  
Jiapan Guo ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Automatic Segmentation ◽  
Maxillofacial Surgery ◽  
Cone Beam ◽  
Oral And Maxillofacial Surgery ◽  
Complex Structures ◽  
Valuable Component ◽  
Metal Implants ◽  
Segmentation Methods ◽  
Automatic Methods

Medical imaging techniques, such as (cone beam) computed tomography and magnetic resonance imaging, have proven to be a valuable component for oral and maxillofacial surgery (OMFS). Accurate segmentation of the mandible from head and neck (H&N) scans is an important step in order to build a personalized 3D digital mandible model for 3D printing and treatment planning of OMFS. Segmented mandible structures are used to effectively visualize the mandible volumes and to evaluate particular mandible properties quantitatively. However, mandible segmentation is always challenging for both clinicians and researchers, due to complex structures and higher attenuation materials, such as teeth (filling) or metal implants that easily lead to high noise and strong artifacts during scanning. Moreover, the size and shape of the mandible vary to a large extent between individuals. Therefore, mandible segmentation is a tedious and time-consuming task and requires adequate training to be performed properly. With the advancement of computer vision approaches, researchers have developed several algorithms to automatically segment the mandible during the last two decades. The objective of this review was to present the available fully (semi)automatic segmentation methods of the mandible published in different scientific articles. This review provides a vivid description of the scientific advancements to clinicians and researchers in this field to help develop novel automatic methods for clinical applications.

scholarly journals Accuracy and practical aspects of semi- and fully automatic segmentation methods for resected brain areas

2020 ◽  
Vol 62 (12) ◽  
pp. 1637-1648
Author(s):  
Karin Gau ◽  
Charlotte S. M. Schmidt ◽  
Horst Urbach ◽  
Josef Zentner ◽  
Andreas Schulze-Bonhage ◽  
...  
Keyword(s):  
Automatic Segmentation ◽  
Dice Similarity Coefficient ◽  
Manual Segmentation ◽  
Brain Areas ◽  
Moderate Amount ◽  
Large Patient ◽  
Segmentation Methods ◽  
Significant Difference ◽  
Fully Automatic ◽  
Neurological Research

Abstract Purpose Precise segmentation of brain lesions is essential for neurological research. Specifically, resection volume estimates can aid in the assessment of residual postoperative tissue, e.g. following surgery for glioma. Furthermore, behavioral lesion-symptom mapping in epilepsy relies on accurate delineation of surgical lesions. We sought to determine whether semi- and fully automatic segmentation methods can be applied to resected brain areas and which approach provides the most accurate and cost-efficient results. Methods We compared a semi-automatic (ITK-SNAP) with a fully automatic (lesion_GNB) method for segmentation of resected brain areas in terms of accuracy with manual segmentation serving as reference. Additionally, we evaluated processing times of all three methods. We used T1w, MRI-data of epilepsy patients (n = 27; 11 m; mean age 39 years, range 16–69) who underwent temporal lobe resections (17 left). Results The semi-automatic approach yielded superior accuracy (p < 0.001) with a median Dice similarity coefficient (mDSC) of 0.78 and a median average Hausdorff distance (maHD) of 0.44 compared with the fully automatic approach (mDSC 0.58, maHD 1.32). There was no significant difference between the median percent volume difference of the two approaches (p > 0.05). Manual segmentation required more human input (30.41 min/subject) and therefore inferring significantly higher costs than semi- (3.27 min/subject) or fully automatic approaches (labor and cost approaching zero). Conclusion Semi-automatic segmentation offers the most accurate results in resected brain areas with a moderate amount of human input, thus representing a viable alternative compared with manual segmentation, especially for studies with large patient cohorts.

scholarly journals Validity and Reliability of Scores Obtained on Multiple-Choice Questions: Why Functioning Distractors Matter

2016 ◽  
Vol 16 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Syed Haris Ali ◽  
Patrick A. Carr ◽  
Kenneth G. Ruit
Keyword(s):  
Multiple Choice ◽  
Validity And Reliability ◽  
Multiple Choice Questions ◽  
Alpha Coefficient ◽  
Cronbach’S Alpha ◽  
Post Intervention ◽  
Free Response ◽  
Cronbach's Alpha ◽  
The Difference ◽  
The Impact

Purpose Plausible distractors are important for accurate measurement of knowledge via multiple-choice questions (MCQs). This study demonstrates the impact of higher distractor functioning on validity and reliability of scores obtained on MCQs. Methods Free-response (FR) and MCQ versions of a neurohistology practice exam were given to four cohorts of Year 1 medical students. Consistently non-functioning multiple-choice distractors (<5% selection frequency) were replaced with those developed from incorrect responses on FR version of the items, followed by administration of the revised MCQ version to subsequent two cohorts. Validity was assessed by comparing an index of expected MCQ difficulty with an index of observed MCQ difficulty, while reliability was assessed via Cronbach’s alpha coefficient before and after replacement of consistently non-functioning distractors. Result Pre-intervention, effect size (Cohen’s d) of the difference between mean expected and observed MCQ difficulty indices was noted to be 0.4 – 0.59. Post-intervention, this difference reduced to 0.15 along with an increase in Cronbach’s alpha coefficient of scores obtained on MCQ version of the exam. Conclusion Multiple-choice distractors developed from incorrect responses on free-response version of the items enhance the validity and reliability of scores obtained on MCQs.

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