scholarly journals Symmetric Reconstruction of Functional Liver Segments and Cross-Individual Correspondence of Hepatectomy

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 852
Author(s):  
Doan Cong Le ◽  
Jirapa Chansangrat ◽  
Nattawut Keeratibharat ◽  
Paramate Horkaew
Keyword(s):  
Computed Tomography ◽  
Surgical Procedures ◽  
Efficient Method ◽  
Anatomical Variations ◽  
Data Availability ◽  
Liver Segmentation ◽  
Accurate Localization ◽  
Liver Surface ◽  
Feature Preserving ◽  
Anatomical Constraints

Accurate localization and analyses of functional liver segments are crucial in devising various surgical procedures, including hepatectomy. To this end, they require the extraction of a liver from computed tomography, and then the identification of resection correspondence between individuals. The first part is usually impeded by inherent deficiencies, as present in medical images, and vast anatomical variations across subjects. While the model-based approach is found viable to tackle both issues, it is often undermined by an inadequate number of labeled samples, to capture all plausible variations. To address segmentation problems by balancing between accuracy, resource consumption, and data availability, this paper presents an efficient method for liver segmentation based on a graph-cut algorithm. One of its main novelties is the incorporation of a feature preserving a metric for boundary separation. Intuitive anatomical constraints are imposed to ensure valid extraction. The second part involves the symmetric conformal parameterization of the extracted liver surface onto a genus-0 domain. Provided with a few landmarks specified on two livers, we demonstrated that, by using a modified Beltrami differential, not only could they be non-rigidly registered, but also the hepatectomy on one liver could be envisioned on another. The merits of the proposed scheme were elucidated by both visual and numerical assessments on a standard MICCAI SLIVER07 dataset.

A Study of Anatomical Variations of Osteomeatal Complex in Correlation with Computed Tomography

2011 ◽  
Vol 4 (1) ◽  
pp. 428-429
Author(s):  
Dr.M.Sasirekha Dr.M.Sasirekha ◽  
◽  
Dr.A.Ashokkumar Dr.A.Ashokkumar
Keyword(s):  
Computed Tomography ◽  
Anatomical Variations ◽  
Osteomeatal Complex

Imaging study of the anatomical variations and the maxillary sinus pathology in patients with missing lateral teeth for the application of dental implants

ORL ro ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 6-12
Author(s):  
Iulian Damian ◽  
Gheorghe-Ionel Comșa
Keyword(s):  
Computed Tomography ◽  
Maxillary Sinus ◽  
Dental Implants ◽  
Preoperative Evaluation ◽  
Anatomical Variations ◽  
Accurate Information ◽  
Maxillary Artery ◽  
Lateral Sinus ◽  
Sinus Wall ◽  
Increased Risk

Preoperative evaluation of maxillary sinus anatomy is very important to avoid surgical complications due to close anatomical relations between the sinus and the posterior maxillary teeth and/or edentulous alveolar ridge. Posterior superior alveolar artery is a branch of the maxillary artery and provides the vascularization of the lateral sinus wall and underlying mucosa. Maxillary artery branches should be taken into consideration during sinus lifting procedures and bone augmentation due to increased risk of bleeding by damaging the artery during the osteotomy. Computed tomography (CT) explores three-dimensional anatomic structures and provides complex and accurate information about them. Cone Beam Computed Tomography (CBCT) offers an accurate view of the teeth and surrounding structures at high resolution, despite low-dose radiation used. In this study, the incidence of anatomical variations and sinus pathology were assessed using CBCT. The aim is to evaluate the presence of sinus pathology (sinus mucosal thickening, oro-antral communications, sinus tumors, cysts, polyps), presence and position of the posterior superior alveolar artery. These issues are important because they are about the limits of the dental implants in the posterior maxillary area. The presence of sinus pathology and anatomical variations may predispose to complications and even failures of implantation therapy.  

scholarly journals Semi-automatic liver segmentation based on probabilistic models and anatomical constraints

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Doan Cong Le ◽  
Krisana Chinnasarn ◽  
Jirapa Chansangrat ◽  
Nattawut Keeratibharat ◽  
Paramate Horkaew
Keyword(s):  
Probabilistic Models ◽  
Contextual Information ◽  
Automatic Segmentation ◽  
Anatomical Variations ◽  
Graph Cut ◽  
Computing Methods ◽  
Liver Segmentation ◽  
Seed Point ◽  
Tissue Separation ◽  
Human Interactions

AbstractSegmenting a liver and its peripherals from abdominal computed tomography is a crucial step toward computer aided diagnosis and therapeutic intervention. Despite the recent advances in computing methods, faithfully segmenting the liver has remained a challenging task, due to indefinite boundary, intensity inhomogeneity, and anatomical variations across subjects. In this paper, a semi-automatic segmentation method based on multivariable normal distribution of liver tissues and graph-cut sub-division is presented. Although it is not fully automated, the method minimally involves human interactions. Specifically, it consists of three main stages. Firstly, a subject specific probabilistic model was built from an interior patch, surrounding a seed point specified by the user. Secondly, an iterative assignment of pixel labels was applied to gradually update the probabilistic map of the tissues based on spatio-contextual information. Finally, the graph-cut model was optimized to extract the 3D liver from the image. During post-processing, overly segmented nodal regions due to fuzzy tissue separation were removed, maintaining its correct anatomy by using robust bottleneck detection with adjacent contour constraint. The proposed system was implemented and validated on the MICCAI SLIVER07 dataset. The experimental results were benchmarked against the state-of-the-art methods, based on major clinically relevant metrics. Both visual and numerical assessments reported herein indicated that the proposed system could improve the accuracy and reliability of asymptomatic liver segmentation.

Orthodontic Pre Grafting Closure of Large Alveolar Bony and Soft Tissue Gaps: A Novel Nonsurgical Protraction of the Lesser Segments in Growing Patients With Cleft Lip and Palate

2021 ◽  
pp. 105566562110076
Author(s):  
Maria Costanza Meazzini ◽  
Noah Cohen ◽  
Valeria Marinella Augusta Battista ◽  
Cristina Incorvati ◽  
Federico Biglioli ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Surgical Procedures ◽  
Efficient Method ◽  
Bone Grafting ◽  
Cleft Lip ◽  
Soft Tissues ◽  
Cleft Lip And Palate ◽  
Face Mask ◽  
Younger Patients ◽  
Good Healing

Background: Closure of wide alveolar clefts with large soft tissue gaps and reconstruction of the dentoalveolar defect are challenging for the surgeon. Some authors successfully used interdental segmental distraction, which requires an additional surgical procedure. Objective: This study evaluates the effectiveness of tooth borne devices utilized to orthopedically advance the lesser segments, with a complete approximation of the soft tissue of the alveolar stumps, allowing traditional simultaneous soft tissue closure and bone grafting, and avoiding the need for supplementary surgery. Methods: Eight growing patients, 2 with unilateral complete cleft lip and palate (UCLP) and 6 with bilateral complete cleft lip and palate (BCLP), with large soft tissue and bony alveolar defects prior to bone grafting were prospectively selected. A banded rapid palatal expander (RPE) in BCLP and a modified RPE in UCLP combined with protraction face mask in younger patients or a modified Alt-Ramec in patients older than 12 years were applied. Radiographic and photographic records were available at T0, at the end of protraction (T1) and at least 1 year after bone grafting (T2). Results: Patients with large gaps showed a significant reduction in the bony cleft area and approximation of the soft tissues at T1. All patients received bone grafting with good healing and ossification at T2. Conclusion: In growing patients with UCLP and BCLP with large gaps, presurgical orthodontic protraction seems to be an efficient method to reduce the cleft defect, minimizing the risk of post grafting fistulas, reducing the need for supplementary surgical procedures.

scholarly journals Reconstruction of four-dimensional computed tomography lung images by applying spatial and temporal anatomical constraints using a Bayesian model

2015 ◽  
Vol 2 (2) ◽  
pp. 024004 ◽  
Author(s):  
Tiancheng He ◽  
Zhong Xue ◽  
Bin S. Teh ◽  
Stephen T. Wong
Keyword(s):  
Computed Tomography ◽  
Bayesian Model ◽  
Anatomical Constraints

Liver segmentation from computed tomography images using cascade deep learning

2021 ◽  
pp. 105095
Author(s):  
José Denes Lima Araújo ◽  
Luana Batista da Cruz ◽  
João Otávio Bandeira Diniz ◽  
Jonnison Lima Ferreira ◽  
Aristófanes Corrêa Silva ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Deep Learning ◽  
Liver Segmentation ◽  
Computed Tomography Images

scholarly journals Discrepancies in interpretation of night-time emergency computed tomography scans by radiology residents

2018 ◽  
Vol 7 (10) ◽  
pp. 205846011880723
Author(s):  
Elias Vaattovaara ◽  
Marko Nikki ◽  
Mika Nevalainen ◽  
Mervi Ilmarinen ◽  
Osmo Tervonen
Keyword(s):  
Computed Tomography ◽  
Emergency Radiology ◽  
Correct Diagnosis ◽  
Anatomical Variations ◽  
Night Time ◽  
Radiology Resident ◽  
Computed Tomography Scans ◽  
Time Work ◽  
Radiology Residents

Background In many emergency radiology units, most of the night-time work is performed by radiology residents. Residents’ preliminary reports are typically reviewed by an attending radiologist. Accordingly, it is known that discrepancies in these preliminary reports exist. Purpose To evaluate the quality of night-time computed tomography (CT) interpretations made by radiology residents in the emergency department. Material and Methods Retrospectively, 1463 initial night-time CT interpretations given by a radiology resident were compared to the subspecialist’s re-interpretation given the following weekday. All discrepancies were recorded and classified into different groups regarding their possible adverse effect for the emergency treatment. The rate of discrepancies was compared between more and less experienced residents and between different anatomical regions. Results The overall rate of misinterpretations was low. In 2.3% (33/1463) of all night-time CT interpretations, an important and clinically relevant diagnosis was missed. No fatalities occurred due to CT misinterpretations during the study. The total rate of discrepancies including clinically irrelevant findings such as anatomical variations was 12.2% (179/1463). Less experienced residents were more likely to miss the correct diagnosis than more experienced residents (18.3% vs. 10.9%, odds ratio [OR] = 1.82, P = 0.001). Discrepancies were more common in body CT interpretations than in neurological CTs (18.1% vs. 9.1%, OR = 2.30, P < 0.0001). Conclusion The rate of clinically important misinterpretations in CT examinations by radiology residents was found to be low. Experience helps in lowering the rate of misinterpretations.

scholarly journals Anatomical Variations of the Recurrent Laryngeal Nerve and Implications for Injury Prevention during Surgical Procedures of the Neck

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 670
Author(s):  
Alison M. Thomas ◽  
Daniel K. Fahim ◽  
Jickssa M. Gemechu
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Surgical Procedures ◽  
Anatomical Variations ◽  
Laryngeal Nerve ◽  
Inferior Thyroid Artery ◽  
Branching Pattern ◽  
The Right ◽  
Relationship Of ◽  
Intrinsic Laryngeal Muscles ◽  
Formalin Fixed

Accurate knowledge of anatomical variations of the recurrent laryngeal nerve (RLN) provides information to prevent inadvertent intraoperative injury and ultimately guide best clinical and surgical practices. The present study aims to assess the potential anatomical variability of RLN pertaining to its course, branching pattern, and relationship to the inferior thyroid artery, which makes it vulnerable during surgical procedures of the neck. Fifty-five formalin-fixed cadavers were carefully dissected and examined, with the course of the RLN carefully evaluated and documented bilaterally. Our findings indicate that extra-laryngeal branches coming off the RLN on both the right and left side innervate the esophagus, trachea, and mainly intrinsic laryngeal muscles. On the right side, 89.1% of the cadavers demonstrated 2–5 extra-laryngeal branches. On the left, 74.6% of the cadavers demonstrated 2–3 extra-laryngeal branches. In relation to the inferior thyroid artery (ITA), 67.9% of right RLNs were located anteriorly, while 32.1% were located posteriorly. On the other hand, 32.1% of left RLNs were anterior to the ITA, while 67.9% were related posteriorly. On both sides, 3–5% of RLN crossed in between the branches of the ITA. Anatomical consideration of the variations in the course, branching pattern, and relationship of the RLNs is essential to minimize complications associated with surgical procedures of the neck, especially thyroidectomy and anterior cervical discectomy and fusion (ACDF) surgery. The information gained in this study emphasizes the need to preferentially utilize left-sided approaches for ACDF surgery whenever possible.

scholarly journals Cone beam-computed tomography as an indispensable tool in the management of radiculous premolar: a case report

2016 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Shristhi Sharma ◽  
Ananth Raghav Sharma ◽  
Vivek Kumar Rai ◽  
Ronak Choudhary
Keyword(s):  
Computed Tomography ◽  
Case Report ◽  
Cone Beam Computed Tomography ◽  
Anatomical Variations ◽  
Endodontic Treatment ◽  
Cone Beam ◽  
Internal Anatomy ◽  
Indispensable Tool ◽  
Rule Out

Background: Internal anatomy of maxillary first premolars is particularly multifaceted on account of the variation in number of roots and canal configuration. Maxillary first premolars with 3 roots are called as small molar or “radiculous” because of their similar anatomy to the maxillary first molars. The most demanding step in endodontic treatment is identification and proper access to pulp canals of certain teeth with atypical canal configurations. Methods of identification of such premolars can be by various aides.Case Presentation: The present case describes the application of Cone Beam-Computed Tomography in the diagnosis of extra root with extra canal in a three rooted maxillary right first premolar.Conclusions: Proper knowledge of the anatomical variations is a must for an endodontist to make a treatment successful. Utilizing the latest technology along with the traditional concepts can surely rule out the inaccuracy in the treatment involved in such cases.

Sign in / Sign up

Export Citation Format

Share Document