Search results for "three-dimensional"
showing 10 items of 370 documents
Territorial belonging of the middle hepatic vein in living liver donor candidates evaluated by three-dimensional computed tomographic reconstruction …
2009
Abstract Background Postoperative venous congestion can lead to graft and remnant liver failure in living donor liver transplantation. This study was designed to delineate ‘territorial belonging’ of the middle hepatic vein (MHV) and to identify hepatic venous anatomy at high risk of outflow congestion. Methods MHV belonging patterns for right (RHL) and left (LHL) hemilivers were evaluated by three-dimensional computed tomographic reconstruction and virtual hepatectomy in 138 consecutive living liver donor candidates. Results The right hepatic vein (RHV) was dominant in 84·1 per cent and an accessory inferior hepatic vein (IHV) was present in 47·1 per cent of livers. Three MHV belonging type…
Maintenance of Integrity of Upper Facet Joints during Simulated Percutaneous Pedicle Screw Insertion Using 2D versus 3D Planning
2019
Background No studies have directly and quantitatively compared two-dimensional (2D) and three-dimensional (3D) planning as applied during conventional percutaneous or navigated percutaneous pedicle screw placement. Study Aims This lumbar pedicle-based stabilization simulation study aimed to investigate the risk of upper facet joint violation (FJV) during posterior percutaneous pedicle screw placement with conventional 2D planning of screw implantation (as a model for fluoroscopically guided screws) compared with 3D planning (as used with navigation techniques). Methods The placement of monosegmental lumbar pedicle screws using the data sets of 250 consecutive patients was simulated. Conve…
3D geometric morphometric analysis of variation in the human lumbar spine
2019
[Objectives]: The shape of the human lumbar spine is considered to be a consequence of erect posture. In addition, several other factors such as sexual dimorphism and variation in genetic backgrounds also influence lumbar vertebral morphology. Here we use 3D geometric morphometrics (GM) to analyze the 3D morphology of the lumbar spine in different human populations, exploring those potential causes of variation.
Exercise loading history and femoral neck strength in a sideways fall: A three-dimensional finite element modeling study
2016
Over 90% of hip fractures are caused by falls. Due to a fall-induced impact on the greater trochanter, the posterior part of the thin superolateral cortex of the femoral neck is known to experience the highest stress, making it a fracture-prone region. Cortical geometry of the proximal femur, in turn, reflects a mechanically appropriate form with respect to habitual exercise loading. In this finite element (FE) modeling study, we investigated whether specific exercise loading history is associated with femoral neck structural strength and estimated fall-induced stresses along the femoral neck. One hundred and eleven three-dimensional (3D) proximal femur FE models for a sideways falling situ…
Three-dimensional sonographic diagnosis of a large cystic neck lymphangioma.
2004
Lymphangiomas are fairly well-circumscribed benign masses of lymphatic vessels or channels that vary in size, are usually greatly dilated, and are lined with normal endothelial cells. They may be classified into 3 groups: lymphangioma simplex, consisting of capillary-sized channels; cavernous lymphangiomas, consisting of dilated channels with a fibrous adventitial covering; and cystic lymphangiomas, or hygromas, composed of multiple cysts of varying sizes that are lined with endothelial cells. Mixed types may coexist within a given lesion. Although lymphangiomas can occur in any part of the body where lymphatic ducts are located, 95% of them are found in the neck, the head, or the axilla. 1…
Reference Ranges and Distribution of Placental Volume by 3-Dimensional Virtual Organ Computer-Aided Analysis Between 11 Weeks and 13 Weeks 6 Days
2013
OBJECTIVES The purpose of this study was to determine the feasibility, reproducibility, and distribution of placental volume measurements according to the crown-rump length between 11 weeks and 13 weeks 6 days. METHODS Images were acquired in 128 pregnancies followed in Burgundy during first-trimester screening sonography using an abdominal 3-dimensional transducer. The placental volume was then calculated by the virtual organ computer-aided analysis method with a rotation angle of 30° by a single operator. RESULTS Placental volumes ranged from 33.3 to 107.6 cm(3) with a mean ± SD of 62.3 ± 14.8 cm(3); the 5th and 10th percentiles were 38.0 and 44.20 cm(3), respectively, whereas the 90th an…
Somatotopic organization of the corticospinal tract in the human brainstem: a MRI-based mapping analysis.
2005
To investigate the incompletely understood somatotopical organization of the corticospinal tract in the human brainstem, we performed a voxel-based statistical analysis of standardized magnetic resonance scans of 41 prospectively recruited patients with pyramidal tract dysfunction caused by acute brainstem infarction. Motor hemiparesis was rated clinically and by the investigation of motor evoked potentials to arms and legs. Infarction affected the pons in 85% of cases. We found the greatest level of significance of affected brainstem areas between the pontomesencephalic junction and the mid pons. Lesion location was significantly more dorsal in patients with hemiparesis affecting more prox…
Assessment of the Tricuspid Valve Morphology by Transthoracic Real-Time-3D-Echocardiography
2005
Aim: To demonstrate the feasibility of transthoracic three-dimensional real-time echocardiography (3D-TTE) supplemental to routine assessments of the tricuspid valve and to analyze interrater agreement. Methods: Twenty healthy subjects and 74 patients with right ventricular failure were examined with conventional 2D and additionally 3D-TTE (SONOS 7500, Philips, Netherlands). The 3D exams were performed and recorded by one of two raters. The recordings were evaluated offline and independently by both raters for visualization of morphological and functional features of the tricuspid valve according to a subjective 3-point scale. Statistical analyses were performed for interrater agreement and…
A classification study of kinematic gait trajectories in hip osteoarthritis
2014
The clinical evaluation of patients in hip osteoarthritis is often done using patient questionnaires. While this provides important information it is also necessary to continue developing objective measures. In this work we further investigate the studies concerning the use of 3D gait analysis to attain this goal. The gait analysis was associated with machine learning methods in order to provide a direct measure of patient control gait discrimination. The applied machine learning method was the support vector machine (SVM). Applying the SVM on all the measured kinematic trajectories, we were able to classify individual patient and control gait cycles with a mean success rate of 88%. With th…
How Technology Can Impact Surgeon Performance: A Randomized Trial Comparing 3-Dimensional versus 2-Dimensional Laparoscopy in Gynecology Oncology
2016
This randomized clinical trial (Canadian Task Force classification I) aimed to compare 2-dimension (2-D) versus 3-dimensional (3-D) laparoscopic hysterectomy and pelvic lymphadenectomy in endometrial and cervical cancer patients. Between December 2014 and March 2015, 90 patients were enrolled: 29 (32.2%) with early or locally advanced cervical cancer after neoadjuvant treatment and 61 (67.8%) with early-stage endometrial cancer. Patients were randomly assigned to undergo 2-D (Group A, n = 48 [53.3%]) or 3-D (Group B, n = 42 [46.7%)]) laparoscopy. Baseline characteristics were superimposable in the 2 groups. Median operative time was similar in the 2 groups. Median estimated blood loss durin…