background and aims. in periapical radiographic technique, the changes will be visible only after considerable deposition or resorption while digital subtraction technique visualizes slight density changes. this study was aimed to compare visualization of density changes in conventional periapical radiographs and digital subtraction technique with or without image enhancement. materials and met...

background: gold nanoparticles (gnps) have been shown as a good radiosensitizer. in combination with radiotherapy, several studies with orthovoltage x-rays have shown considerable dose enhancement effects. this paper reports the dose enhancement factor (def) due to gnps in 18 megavoltage (mv) beams. materials and methods: different geometrical 50-nm gnps configurations at a concentration of 5 m...

we reported ct of a case of giant organized hematoma originating from the inferior turbinate without any paranasal sinuses involvement, with an emphasis on different patterns of enhancement of the tumor on enhanced ct scans. this case was exceptional because of unusual location and difficulties in diagnosis. moreover, organized hematoma of nasal cavity should be considered in the differential d...

conclusions although in our study washout pattern was the most powerful indicator for malignant pathology in non mass like enhancing lesions, more studies with larger sample size needs in this regard. background several studies on the diagnostic efficacy of mri has not real consensus for the accuracy of mri characteristics in non mass like breast lesions, and the number of malignant lesions in ...

Introduction: Bismuth-based nanoparticles having high atomic number and electron density, besides of being utilized as CT contrast agent, stand as a strongly proposed method for dose enhancement in radiotherapy. Embedded nanoparticle in polymer gel dosimeter poses the first step to assess the dose enhancement capability in nanoparticles. To this end, MAGICA gel dosimeter, whic...

Introduction: Secondary radiation such as photoelectrons, Auger electrons and characteristic radiations cause a local boost in dose for a tumor when irradiated with an external X-ray beam after being loaded with elements capable of activating the tumor, e.g.; I and Gd. Materials and Methods:  In this investigation, the MCNPX code was used for simulation and calculation of dose enhancement facto...

purpose: to record the mri features of primary central nervous system lymphoma (pcnsl) and compare these properties in monofocal and multifocal disease. methods: eleven cases of monofocal disease were compared to 9 cases of multifocal disease. all patients were examined by non-enhanced and contrast-enhanced mri. tumor location, signal intensity, enhancement characteristics, age distribution, pe...

This study aimed to investigate the impact of textual enhancement and metalinguistic explanation as focus-on-form tasks tending to encourage the acquisition of nominal clauses (NCs) in English. It explored (a) whether textual enhancement and metalinguistic explanation would promote and enhance the knowledge of NCs, (b) whether these two tasks would differ in terms of enhancing learners' knowled...

the speech enhancement techniques are often employed to improve the quality and intelligibility of the noisy speech signals. this paper discusses a novel technique for speech enhancement which is based on singular value decomposition. this implementation utilizes a genetic algorithm based optimization method for reducing the effects of environmental noises from the singular vectors as well as t...