Parametric Level-sets Enhanced To Improve Reconstruction (PaLEnTIR)

In this paper, we consider the restoration and reconstruction of piecewise constant objects in two and three dimensions using PaLEnTIR, a significantly enhanced Parametric level set (PaLS) model relative to the current state-of-the-art. The primary contribution of this paper is a new PaLS formulation which requires only a single level set function to recover a scene with piecewise constant objects possessing multiple unknown contrasts. Our model offers distinct advantages over current approaches to the multi-contrast, multi-object problem, all of which require multiple level sets and explicit estimation of the contrast magnitudes. Given upper and lower bounds on the contrast, our approach is able to recover objects with any distribution of contrasts and eliminates the need to know either the number of contrasts in a given scene or their values. We provide an iterative process for finding these space-varying contrast limits. Relative to most PaLS methods which employ radial basis functions (RBFs), our model makes use of non-isotropic basis functions, thereby expanding the class of shapes that a PaLS model of a given complexity can approximate. Finally, PaLEnTIR improves the conditioning of the Jacobian matrix required as part of the parameter identification process and consequently accelerates the optimization methods by controlling the magnitude of the PaLS expansion coefficients, fixing the centers of the basis functions, and the uniqueness of parametric to image mappings provided by the new parameterization. We demonstrate the performance of the new approach using both 2D and 3D variants of X-ray computed tomography, diffuse optical tomography (DOT), denoising, deconvolution problems. Application to experimental sparse CT data and simulated data with different types of noise are performed to further validate the proposed method.Comment: 31 pages, 56 figure

The relationship between Hill-Sachs lesion and recurrent anterior shoulder dislocation

WOS: 000254244600004PubMed: 17515227The relationship between the number of shoulder dislocations and the depth and percent of head involvement of the Hill-Sachs lesions was investigated in this study. Thirty patients with recurrent anterior dislocation of the shoulder were divided into three groups according to the numbers of dislocations they had presented : Group 1 : 1 to 5 dislocations; Group 2 : 6 to 20 Group 3 : over 20. The mean percentage of head involvement was 11.9% in the first group, 25.4% in the second group and 26% in the third group of patients with Hill-Sachs lesions. The average depth of the Hill-Sachs lesions was 4.14 mm in the first group, 5.13 mm in the second group and 4.38 mm in the third group. Based on these findings, it appears that there is a correlation between the number of dislocations and the extent and depth of the Hill-Sachs lesions. Surgical treatment should therefore be performed as early as possible in patients with recurrent anterior dislocation of the shoulder, in order to prevent progression of the Hill-Sachs lesion which can become by itself a cause of instability

Open repair of Bankart lesions using suture anchors in hard workers

PubMed: 17260602The surgical techniques applied to recurrent anterior dislocation of the shoulder, especially in hard working patients, must reconstruct a stable shoulder joint with a good range of motion, which will not redislocate, so the patients can return to their hardworking duties. The aim of this study was to evaluate the results of open Bankart repairs with suture anchors, in high-demand sportsmen and hard workers with recurrent anterior shoulder dislocation. Thirty shoulders of 29 patients were included in the study. All patients were active hard workers. A modified deltopectoral incision was used and Mitek GII Suture Anchors were implanted with 7-10 mm intervals into the bone-cartilage zone of the glenoid rim. Average follow-up time was 30 months (range, 22-38). Postoperative results were analysed according to the Rowe Scoring System. We obtained good and excellent results in 93.3% of cases. The open Bankart repair using suture anchors appeared in this study as a reliable technique for hard workers or physically high-demand patients. © 2006, Acta Orthopædica Belgica

Contrary intermittent skin release of complete syndactyly without skin graft in adults

WOS: 000232282800005PubMed: 16186698Introduction: There are many different surgical treatment techniques of complete syndactyly. Most of them are techniques involving using skin grafts. We developed a surgical technique that does not require skin grafts, which cause problems in the distal nail border pulp and interdigital web space. Materials and Methods: Syndactyly release was performed in 12 web spaces of I I adult male patients. The average age was 21. In addition to a zig-zag incision, contrary intermittent skin release was performed. Primary coverage of the interdigital web space and nail border pulp was achieved without skin graft. Results: We obtained good results by the contrary intermittent skin release method that we developed, in adult complete syndactyly patients who had no chance for the surgical treatment due to several reasons, previously. Conclusion: With such a surgical technique, in our cases we obtained successful results, both cosmetic and functional. The presented technique is an alternative method for syndactyly release without using skin graft in adult patients

The use of computed tomography to determine femoral component size: A study of cadaver femora

PubMed: 16536219Computed tomography is used to assess whether ideal femoral component size in knee arthroplasty can be made more accurately. Ideal femoral component size was measured on radiography, computed tomography, and by direct measurement of 20 cadaver femora and analyzed statistically. There was no significance between the tomographically anticipated ideal femoral component size and ideal femoral size values (Wilcoxon W 388.5; p 0.565). There was difference between radiographically anticipated ideal femoral size and ideal femoral size values (Wilcoxon W 324.5; p 0.020). Anticipating the ideal femoral size can be made more precisely with computed tomography than radiographs in cadaver femora. Anticipating the ideal femoral component size by computed tomography may solve the problems in "in-between sizes." Future total knee designs may be manufactured in more anatomic sizes

Computerized tomography scout view for determining distal femoral resection angle in intramedullary instrumentation of total knee arthroplasty

Cirpar, Meric/0000-0001-9669-6513WOS: 000243619300015PubMed: 16924560This study aims to investigate the results of distal femoral resection by determining the difference between mechanical and anatomical axes of femur using computerized tomography (CT) scout views in pre-operative planning of total knee arthroplasty. CT scout view of the lower extremities was taken before and after the operation in 16 patients undergoing total knee arthroplasty. Distal femoral resection was performed according to the previously determined ideal resection angle (IRA) using intramedullary instrumentation. At post-operative scanogram, femoral component deviation (FCD) was measured. The results were statistically analyzed. The average IRA was 6.95 (5-9) degrees. At post-operative measurements, the average FCD was 0.63 (0-3) degrees. CT scout films improve the accuracy in distal femoral resection and femoral component alignment