scholarly journals Exploring the Functionality of Mesh-to-Mesh Value Comparison in Pair-Matching and Its Application to Fragmentary Remains

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1303
Author(s):  
Zoe McWhirter ◽  
Mara A. Karell ◽  
Ali Er ◽  
Mustafa Bozdag ◽  
Oguzhan Ekizoglu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Roc Analysis ◽  
Three Dimensional ◽  
Turkish Population ◽  
New Method ◽  
Ct Scans ◽  
Different Types ◽  
Pair Matching ◽  
Commingled Remains

Many cases encountered by forensic anthropologists involve commingled remains or isolated elements. Common methods for analysing these contexts are characterised by limitations such as high degrees of subjectivity, high cost of application, or low proven accuracy. This study sought to test mesh-to-mesh value comparison (MCV), a relatively new method for pair-matching skeletal elements, to validate the claims that the technique is unaffected by age, sex and pathology. The sample consisted of 160 three-dimensional clavicle models created from computed tomography (CT) scans of a contemporary Turkish population. Additionally, this research explored the application of MVC to match fragmented elements to their intact counterparts by creating a sample of 480 simulated fragments, consisting of three different types based on the region of the bone they originate from. For comparing whole clavicles, this resulted in a sensitivity value of 87.6% and specificity of 90.9% using ROC analysis comparing clavicles. For the fragment comparisons, each type was compared to the entire clavicles of the opposite side. The results included a range of sensitivity values from 81.3% to 87.6%. Overall results are promising and the MVC technique seems to be a useful technique for matching paired elements that can be accurately applied to a Modern Turkish sample.

scholarly journals A new method for estimating three-dimensional movement of the patella using a surface mapping method and computed tomography

Heliyon ◽  
2020 ◽  
Vol 6 (8) ◽  
pp. e04729
Author(s):  
Takuma Inai ◽  
Tomoya Takabayashi ◽  
Satoshi Watanabe ◽  
Masahiro Ikezu ◽  
Fumiya Kaneko ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Mapping Method ◽  
New Method ◽  
Surface Mapping

scholarly journals Sagittal discrepancies of the jaw in a Bangladeshi cohort: three-dimensional computed tomography analysis

2019 ◽  
Vol 47 (8) ◽  
pp. 3613-3622
Author(s):  
Mushrath Islam ◽  
Ayman Hameed Uraibi ◽  
Arkan Al Azzawi ◽  
Mohammad Khursheed Alam ◽  
Asilah Yusof
Keyword(s):  
Computed Tomography ◽  
3D Imaging ◽  
Three Dimensional ◽  
Ct Scans ◽  
Radiology Department ◽  
Men And Women ◽  
Essential Step ◽  
Beta Angle ◽  
Spss Software ◽  
Tomography Analysis

Objectives In orthodontic diagnosis and treatment planning, the assessment of skeletal jaw relationships is an essential step. This study aimed to evaluate skeletal jaw relationships in a Bangladeshi cohort by using traditional (ANB angle and Wits appraisal) and newly described (Beta angle, W angle, and Yen angle) sagittal measurements in three-dimensional (3D) computed tomography (CT). Methods The radiology department conducted CT scans of Bangladeshi patients. Mimics 3D imaging software (Materialise) was used to process the CT images and evaluate 3D sagittal measurements. SPSS software (IBM) was used to assess significant differences in the data at a confidence level of 5%. Independent-samples t-tests were used to evaluate sexual dimorphism for the measured values. Results In total, 85 men and 32 women were included in this study. All measurements were equivalent to the existing standards. There were no significant differences in the acquired values between men and women. Measurements were consistent with Class I normal classification. Conclusions This study established 3D CT standards for ANB, Wits appraisal, Beta angle, W angle, and Yen angle in Bangladeshi patients.

Anterior lengthening in scoliosis occurs only in the disc and is similar in different types of scoliosis

2021 ◽  
Author(s):  
S de Reuver ◽  
RC Brink ◽  
JF Homans ◽  
L Vavruch ◽  
H Tropp ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Congenital Scoliosis ◽  
Intervertebral Discs ◽  
Ct Scans ◽  
Scoliotic Deformity ◽  
Different Types ◽  
Vertebral Bodies ◽  
Bony Abnormality

Relative anterior spinal overgrowth (RASO) was proposed as a generalized growth disturbance and a potential initiator of adolescent idiopathic scoliosis (AIS). However, anterior lengthening was also observed in neuromuscular (NM) scoliosis, was shown to be restricted to the apical areas and to be located in the intervertebral discs, not in the bone. In this study the goal was to determine if other scoliotic curves of known origin exhibit the similar mechanism of anterior lengthening without changes in the vertebral body. Therefore CT-scans of 18 patients in whom a short segment congenital malformation had led to a long thoracic compensatory curve without bony abnormality were included. Of each vertebral body and intervertebral disc in the compensatory curve, the anterior and posterior length was measured on CT-scans in the exact mid-sagittal plane, corrected for deformity in all three planes. The total AP% of the compensatory curve in congenital scoliosis showed a lordosis (+1.8%) that differed from the kyphosis in non-scoliotic controls (-3.0%; p<0.001), and was comparable to AIS (+1.2%) and NM scoliosis (+0.5%). This anterior lengthening was not located in the bone; the vertebral body AP% showed a kyphosis (-3.2%), similar to non-scoliotic controls (-3.4%), as well as AIS (-2.5%) and NM scoliosis (-4.5%; p=1.000). However, the disc AP% showed a lordosis (+24.3%), which sharply contrasts to the kyphotic discs of controls (-1.5%; p<0.001), but was similar to AIS (+17.5%) and NM scoliosis (+20.5%). The results demonstrate that anterior lengthening is part of the three-dimensional deformity in different types of scoliosis and is exclusively located in the intervertebral discs. The bony vertebral bodies maintain their kyphotic shape, which indicates that there is no active bony overgrowth. Anterior lengthening appears to be a passive result of any scoliotic deformity, rather than being related to the specific cause of AIS.

Planning Mandibular Distraction: Preliminary Report

1995 ◽  
Vol 32 (1) ◽  
pp. 71-76 ◽  
Author(s):  
H. Wolfgang Losken ◽  
Gary T. Patterson ◽  
Spiros A. Lazarou ◽  
Timothy Whitney
Keyword(s):  
Computed Tomography ◽  
Preliminary Report ◽  
Three Dimensional ◽  
Ct Scans ◽  
Obtuse Angle ◽  
3D Ct ◽  
Mandibular Angle ◽  
Mandibular Distraction ◽  
Different Ages ◽  
Horizontal Ramus

Normal lengths of the vertical ramus, body, and angle of the mandible at different ages are presented. Before mandibular distraction is embarked on, the extent of the deficiency of the mandible is assessed. The length of the vertical ramus and body are measured on cephalometric radiographs or three-dimensional computed tomography (3D CT) scans. Deficiency of the length of the mandible is calculated. The position of the pin placement angle (from the horizontal ramus) is calculated by means of the following formula: 180 degrees minus mandibular angle times vertical ramus deficiency divided by total deficiency. Placing the pins correctly will result in correction of the vertical ramus and body deficiency of the mandible and the excessively obtuse angle of the mandible will become more acute.

scholarly journals Quantifying avian inertial properties using calibrated computed tomography

2022 ◽  
Vol 225 (1) ◽  
Author(s):  
Nicholas E. Durston ◽  
Yusuf Mahadik ◽  
Shane P. Windsor
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Ct Scans ◽  
Birds Of Prey ◽  
Distribution Data ◽  
Centre Of Mass ◽  
Body Segment ◽  
Dynamics Modelling ◽  
Non Destructive

ABSTRACT Estimating centre of mass and mass moments of inertia is an important aspect of many studies in biomechanics. Characterising these parameters accurately in three dimensions is challenging with traditional methods requiring dissection or suspension of cadavers. Here, we present a method to quantify the three-dimensional centre of mass and inertia tensor of birds of prey using calibrated computed tomography (CT) scans. The technique was validated using several independent methods, providing body segment mass estimates within approximately 1% of physical dissection measurements and moment of inertia measurements with a 0.993 R2 correlation with conventional trifilar pendulum measurements. Calibrated CT offers a relatively straightforward, non-destructive approach that yields highly detailed mass distribution data that can be used for three-dimensional dynamics modelling in biomechanics. Although demonstrated here with birds, this approach should work equally well with any animal or appendage capable of being CT scanned.

scholarly journals Three-dimensional assessment of unilateral subcondylar fracture using computed tomography after open reduction

2014 ◽  
Vol 47 (02) ◽  
pp. 203-209 ◽  
Author(s):  
Sathya Kumar Devireddy ◽  
R. V. Kishore Kumar ◽  
Rajasekhar Gali ◽  
Sridhar Reddy Kanubaddy ◽  
Mallikarjuna Rao Dasari ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Statistical Difference ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Mandibular Condyle ◽  
Clinical Results ◽  
Considerable Change ◽  
Ct Scans ◽  
Open Method ◽  
Condylar Fractures

ABSTRACT Objective: The aim was to assess the accuracy of three-dimensional anatomical reductions achieved by open method of treatment in cases of displaced unilateral mandibular subcondylar fractures using preoperative (pre op) and postoperative (post op) computed tomography (CT) scans. Materials and Methods: In this prospective study, 10 patients with unilateral sub condylar fractures confirmed by an orthopantomogram were included. A pre op and post op CT after 1 week of surgical procedure was taken in axial, coronal and sagittal plane along with three-dimensional reconstruction. Standard anatomical parameters, which undergo changes due to fractures of the mandibular condyle were measured in pre and post op CT scans in three planes and statistically analysed for the accuracy of the reduction comparing the following variables: (a) Pre op fractured and nonfractured side (b) post op fractured and nonfractured side (c) pre op fractured and post op fractured side. P <; 0.05 was considered as significant. Results: Three-dimensional anatomical reduction was possible in 9 out of 10 cases (90%). The statistical analysis of each parameter in three variables revealed (P <; 0.05) that there was a gross change in the dimensions of the parameters obtained in pre op fractured and nonfractured side. When these parameters were assessed in post op CT for the three variables there was no statistical difference between the post op fractured side and non fractured side. The same parameters were analysed for the three variables in pre op fractured and post op fractured side and found significant statistical difference suggesting a considerable change in the dimensions of the fractured side post operatively. Conclusion: The statistical and clinical results in our study emphasised that it is possible to fix the condyle in three-dimensional anatomical positions with open method of treatment and avoid post op degenerative joint changes. CT is the ideal imaging tool and should be used on a regular basis for cases of condylar fractures.

scholarly journals Optimization of Computed Tomography Angiography Protocols for Follow-Up Type B Aortic Dissection Patients by Using 3D Printed Model

2021 ◽  
Vol 11 (15) ◽  
pp. 6844
Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Shirley Jansen ◽  
Zhonghua Sun
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Aortic Dissection ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Ct Scans ◽  
Patient Specific ◽  
Type B ◽  
Type B Aortic Dissection ◽  
3D Printed

Thoracic endovascular aortic repair (TEVAR) is a life-saving therapy for type B aortic dissection (TBAD). However, surveillance computed tomography (CT) scans in post-TEVAR patients are associated with high radiation dose, thus resulting in potential risk of radiation-induced malignancy. In this study, we developed a patient-specific three-dimensional (3D) printed phantom with stent grafts in situ, then scanned the phantom with different CT protocols to determine the optimal scanning parameters for post-treatment patients. The CT scans were conducted with different kVp and pitch values (80, 100, 120 kVp and pitch of 1.2, 1.5, 2.0, 2.5), resulting in a total of 12 datasets. Signal-to-noise ratio (SNR) was measured to determine and compare the image quality between different datasets. Results showed no significant differences in SNR between different kVp when the pitch value was 1.2. At low pitch values, a decrease in kVp from 120 to 80 led to a significant effective dose reduction by more than 20%. SNR decreased by 30% when pitch was increased from 1.2 to 2.5 at 80 kVp, and 20% at 120 kVp. In contrast, there was only a 3.9% decrease in SNR when kVp was reduced from 120 to 80 at pitch 1.2, and 15.9% at pitch 2.5. High pitch with 100 kVp can effectively reduce the dose while maintaining image quality.

scholarly journals Revealing the Secrets of Chinese Ivory Puzzle Balls: Quantifying the Crafting Process Using X-Ray Computed Tomography

2021 ◽  
Vol 69 (3) ◽  
pp. 244-263
Author(s):  
Robert Van Liere ◽  
Ching-Ling Wang
Keyword(s):  
Computed Tomography ◽  
Eighteenth Century ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Morphological Properties ◽  
X Ray ◽  
National Palace Museum ◽  
Different Types ◽  
X Ray Computed ◽  
Novel Method

Chinese ivory puzzle balls are known for their beauty, finesse and their ability to intrigue viewers. From the eighteenth century until recently, they have been crafted by turning, using a simple lathe and a set of drilling and carving tools developed in the eighteenth century. The craft of Chinese ivory puzzle balls has been described as the ‘devil’s work’, as it requires a great deal of proficiency, accuracy and patience. This study presents a novel method for quantifying the crafting process of Chinese ivory puzzle balls. The method is based on measuring the morphological properties of ivory balls in three-dimensional images obtained using X-ray Computed Tomography (CT) scanning techniques. The accuracy of the crafting process is obtained by comparing the measured properties with an underlying mathematical model of the ball. We apply the proposed method to ivory balls from the Rijksmuseum in Amsterdam and the National Palace Museum in Taipei. The results show substantial differences in the accuracy of the crafting process. From an art-historical perspective, the results show that the accuracy of the crafting process evolved during the eighteenth century. They also suggest that the ivory balls we have analyzed have been crafted with different types of turning tools.

scholarly journals Comparative study of glenoid version and inclination using two-dimensional images from computed tomography and three-dimensional reconstructed bone models

2020 ◽  
Vol 23 (3) ◽  
pp. 119-124
Author(s):  
Chang-Hyuk Choi ◽  
Hee-Chan Kim ◽  
Daewon Kang ◽  
Jun-Young Kim
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Ct Scans ◽  
3D Measurement ◽  
Two Dimensional ◽  
Glenoid Version ◽  
Observer Reliability ◽  
3D Measurements ◽  
Orthopedic Surgeons ◽  
2D Images

Background: This study was performed to compare glenoid version and inclination measured using two-dimensional (2D) images from computed tomography (CT) scans or three-dimensional (3D) reconstructed bone models.Methods: Thirty patients who had undergone conventional CT scans were included. Two orthopedic surgeons measured glenoid version and inclination three times on 2D images from CT scans (2D measurement), and two other orthopedic surgeons performed the same measurements using 3D reconstructed bone models (3D measurement). The 3D-reconstructed bone models were acquired and measured with Mimics and 3-Matics (Materialise).Results: Mean glenoid version and inclination in 2D measurements were –1.705º and 9.08º, respectively, while those in 3D measurements were 2.635º and 7.23º. The intra-observer reliability in 2D measurements was 0.605 and 0.698, respectively, while that in 3D measurements was 0.883 and 0.892. The inter-observer reliability in 2D measurements was 0.456 and 0.374, respectively, while those in 3D measurements was 0.853 and 0.845.Conclusions: The difference between 2D and 3D measurements is not due to differences in image data but to the use of different tools. However, more consistent results were obtained in 3D measurement. Therefore, 3D measurement can be a good alternative for measuring glenoid version and inclination.

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