Thorax organ dose estimation in computed tomography based on patient CT data using Monte Carlo simulation

Background: This study presents pati ent specific and organ dose esti mati on in computed tomography (CT) imaging of thorax directly from pati ent CT image using Monte Carlo simulati on. Pati ent's CT image is considered as the pati ent specific phantom and the best representati ve of pati ent physical index in order to calculate specific organ dose. Materials and Methods: EGSnrc/BEAMnrc Monte Carlo (MC) System was used for CT scanner simulati on and DOSXYZnrc was used in order to produce pati ent specific phantom and irradiati on of photons to phantom in step and shoot mode (axial mode). In order to calculate pati ent thorax organ dose, pati ent CT image of thorax as voxelized phantom was divided to a 64x64x20 matrix and 6.25 x 6.25 x 6.25 mm3 voxel size and this phantom was imported to DOSXYZnrc code. MC results in unit of Gy/parti cle were converted to absorbed dose in unit of mGy by a conversion factor (CF). We calculated pati ent thorax organ dose in MC simulati on from all irradiated slices, in 120 kV and 80 kV photon energies. Results: Effecti ve dose was obtained from organ dose and organ weighti ng factor. Esophagus and spinal cord received the lowest, and bone received the highest dose. In our study, effecti ve dose in CT of thorax was 7.4 mSV and 1.8 mSv in 120 and 80 kV, respecti vely. Conclusion: The results of this study might be used to provide the actual pati ent organ dose in CT imaging and calculati on of real effecti ve dose based on organ dose

Standardized Treatment of Active Tuberculosis in Patients with Previous Treatment and/or with Mono-resistance to Isoniazid: A Systematic Review and Meta-analysis

Performing a systematic review of studies evaluating retreatment of tuberculosis or treatment of isoniazid mono-resistant infection, Dick Menzies and colleagues find a paucity of evidence to support the WHO-recommended regimen

Pelvic trauma : WSES classification and guidelines

Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.Peer reviewe