Computer-aided segmentation and estimation of indices in brain CT scans

The importance of neuro-imaging as one of the biomarkers for diagnosis and prognosis of pathologies and traumatic cases is well established. Doctors routinely perform linear measurements on neuro-images to ascertain severity and extent of the pathology or trauma from significant anatomical changes. However, it is a tedious and time consuming process and manually assessing and reporting on large volume of data is fraught with errors and variation. In this paper we present a novel technique for segmentation of significant anatomical landmarks using artificial neural networks and estimation of various ratios and indices performed on brain CT scans. The proposed method is efficient and robust in detecting and measuring sizes of anatomical structures on non-contrast CT scans and has been evaluated on images from subjects with ages between 5 to 85 years. Results show that our method has average ICC of ≥0.97 and, hence, can be used in processing data for further use in research and clinical environment

Computer aided assessment of CT scans of traumatic brain injury patients

A thesis submitted in partial fulfilment for the degree of Doctor of PhilosophyOne of the serious public health problems is the Traumatic Brain Injury, also known as silent epidemic, affecting millions every year. Management of these patients essentially involves neuroimaging and noncontrast CT scans are the first choice amongst doctors. Significant anatomical changes identified on the neuroimages and volumetric assessment of haemorrhages and haematomas are of critical importance for assessing the patients’ condition for targeted therapeutic and/or surgical interventions. Manual demarcation and annotation by experts is still considered gold standard, however, the interpretation of neuroimages is fraught with inter-observer variability and is considered ’Achilles heel’ amongst radiologists. Errors and variability can be attributed to factors such as poor perception, inaccurate deduction, incomplete knowledge or the quality of the image and only a third of doctors confidently report the findings. The applicability of computer aided dianosis in segmenting the apposite regions and giving ’second opinion’ has been positively appraised to assist the radiologists, however, results of the approaches vary due to parameters of algorithms and manual intervention required from doctors and this presents a gap for automated segmentation and estimation of measurements of noncontrast brain CT scans. The Pattern Driven, Content Aware Active Contours (PDCAAC) Framework developed in this thesis provides robust and efficient segmentation of significant anatomical landmarks, estimations of their sizes and correlation to CT rating to assist the radiologists in establishing the diagnosis and prognosis more confidently. The integration of clinical profile of the patient into image segmentation algorithms has significantly improved their performance by highlighting characteristics of the region of interest. The modified active contour method in the PDCAAC framework achieves Jaccard Similarity Index (JI) of 0.87, which is a significant improvement over the existing methods of active contours achieving JI of 0.807 with Simple Linear Iterative Clustering and Distance Regularized Level Set Evolution. The Intraclass Correlation Coefficient of intracranial measurements is >0.97 compared with radiologists. Automatic seeding of the initial seed curve within the region of interest is incorporated into the method which is a novel approach and alleviates limitation of existing methods. The proposed PDCAAC framework can be construed as a contribution towards research to formulate correlations between image features and clinical variables encompassing normal development, ageing, pathological and traumatic cases propitious to improve management of such patients. Establishing prognosis usually entails survival but the focus can also be extended to functional outcomes, residual disability and quality of life issues

Cerebral Venous Engorgement in Hydrops Fetalis

A 34-year-old gravida was diagnosed with hydrops fetalis, hydrothorax with cardiac compression, hygroma, ascites, and subcutaneous edema at 20 weeks of gestation..

Rhnull: a rare blood group phenotype

Rhnull phenotype is a rare blood group characterized by the lack of expression of all Rh antigens (D, C, c, E and e) on the red cells. The phenotype is further classified into the regulator and amorph type based on underlying genetic defect. The clinical significance of its recognition is that such patients suffer from Rhnull syndrome associated with osmotically fragile red cells called stomatocytes with subsequent chronic haemolytic anaemia of varying degree. Another importance is that such subjects readily form alloantibodies on exposure to Rh antigens. We report herein rare Rhaull phenotype in a young pregnant female which was detected as a part of routine antenatal work-up for red cell antibody screening and identification

Intestinal Obstruction Changing Etiological Trends

Background: To describe clinical presentation, etiology, and management of patients presenting with intestinal obstruction. Method: From 6th September 2004 to 6 September 2005, 50 patients with provisional diagnosis of intestinal obstruction were admitted from emergency room of Rawalpindi General Hospital. All patients were initially assessed after resuscitation in emergency room. The decision, to operate or manage conservatively, was taken by a consultant. The clinical diagnosis was matched with per-operative findings and histopathology reports. Results: Of the total 50 patients, 42 were males and 8 were female. The age distribution varied from 15 years to 70 years. Mean age was 41.7 ± 13.6.Commonest symptom with which the patients presented was generalized abdominal pain. Most common sign was tachycardia, present in 49 patients. Most common etiology leading to intestinal obstruction was obstructed inguinal hernia in 22 followed by post operative adhesions in 12 patients. Conclusion: Obstructed inguinal hernia is the most common etiology of intestinal obstruction. Early diagnosis and surgical intervention is required to decrease gut ischemia leading to increased morbidity in patient

Effective length factors for solid round chord members of guyed towers.

Chord members of twenty-five all-welded guyed-latticed communication steel tower sections were tested in the Structural Engineering Laboratory of the University of Windsor to determine the effective length factors of the chord members. Two different manufacturers, viz., Pirod Inc., Plymouth, Indiana, and ERI Inc., Chandler, Indiana, provided the test specimens. All tower sections were fabricated from solid round members and were triangular in cross section. Tower sections provided by ERI were 4.57 m (15.0 ft.) long with continuous diagonal bracings welded to the chord members, while those provided by Pirod were 6.09 m (20.0 ft.) long with the diagonal bracings cut and welded to the chord members. The diameters of the chord members varied from 38.1 mm (1.5 in.) to 69.85 mm (2.75 in.) while the diameters of the diagonal bracings varied from 12.7 mm (0.5 in.) to 22.3 mm (0.875 in.). The tower sections were tested in a horizontal position. One chord member of the tower was cut and tested by applying a load at its center while the diagonal bracings remained attached to the chord members. The stiffness contribution of diagonal bracings to the ends of the chord members was also computed numerically. (Abstract shortened by UMI.)Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1999 .Q87. Source: Masters Abstracts International, Volume: 39-02, page: 0553. Adviser: M. K. S. Madugola. Thesis (M.A.Sc.)--University of Windsor (Canada), 2000

Tribological Characterization of Electrical Discharge Machined Surfaces for AISI 304L

Surface treatments are normally carried out after machining. Surface treatment is a costly and time-consuming process. Hence, it makes sense to reduce the requirement of surface treatment as much as possible. Electrical Discharge Machining (EDM) is a frequently used machining process. EDM produces a recast layer on the surface of machined components. The tribological performance of this recast layer is not very well understood. The properties of the recast layer formed as a result of EDM depend upon the discharge current, electrodes and dielectrics. This work aims to study the effects of each on the tribological performance – in terms of the wear depth, friction coefficient, friction force and contact surface temperature of recast layers. Subsequent improvement in the quality of surfaces will significantly reduce the cost and time required to treat surfaces after machining. Hence, various combinations of discharge current, dielectrics and electrodes have been used to characterize and deduce their effects. The tribo-tests are performed in the boundary lubrication regime under pin-on-disc configuration to analyze sliding friction, contact surface temperature and the wear of the recast layers formed on AISI 304L. The surface morphology of the test pins has been performed by Scanning Electron Microscopy (SEM) before and after the tests. The results show that indeed it is possible to control the tribological performance of the recast layers by varying EDM parameters. This approach promises to be a useful methodology to improve the tribological performance of the layers formed after EDM and reduce the time and costs required for surface treatments post machining

Successful use of rituximab in Evans syndrome and refractory immune thrombocytopenic purpura

Immune cytopenias are mediated by auto-antibodies produced by B-lymphocytes. Conventional treatment of immune-mediated haematological disorders includes immunosuppression with steroids and other immune modulating therapies and in some refractory cases, splenectomy. Response rates to conventional and second-line agents are variable and a proportion of patients require lifelong immunosuppression to maintain the disease in remission. Rituximab, an anti- CD 20 monoclonal antibody has gained widespread acceptance in the management of B-cell malignancies. Additionally, it has been used to treat the disorders associated with autoantibody production. We report herein the successful use of Rituximab in the treatment of two patients with autoimmune cytopenias one had Evan\u27s syndrome and other had refractory immune thrombocytopenic purpura. Both of these patients are still in remission at 16 and 25 months following treatment