background: to reduce the dose to normal tissues surrounding the treated breast, a uniform magnetic field was used within a humanoid phantom in breast radiotherapy. materials and methods: monte carlo simulations were performed with geant4, irradiating humanoid phantoms in a magnetic field. to reconstruct phantoms, computed tomography (ct) data slices of four patients were used for the monte car...

introduction: in diagnostic and therapeutic procedures, dosimetric studies are performed on the dosimetric systems in order to comply the radiation safety standards. monte carlo methods are used due to the high complexity and cost of patient-specific phantom construction. the high complexity of the digitized phantoms greatly increases the time and computational task of the monte carlo calculati...

Introduction: Breast cancer is one of the most common known cancers in women all around the world. It is the most common cause of death in women after lung cancer. Radiotherapy is a method for therapy of cancer in which certain dose of high energy radiations is used to destruct cancer cells. Radiotherapy is designed so that radiation of eartain does to the target area in body i...

BACKGROUND Breast cancer is one of the most prevalent forms of cancer in women. Breast-specific gamma imaging (BSGI) is a diagnostic imaging method that uses sestamibi-labelled 99Tc and a dedicated gamma camera to localize malignant lesions in breast tissue. The aim of this study is to investigate if the current acquisition protocol for BSGI at our hospital is optimized for the detection of les...

Augmented reality is applied to ultrasound-guided needle biopsy of the human breast. In a tracked stereoscopic head-mounted display, a physician sees the ultrasound imagery “emanating” from the transducer, properly registered with the patient and the biopsy needle. A physician has successfully used the system to guide a needle into a synthetic tumor within a breast phantom and examine a human p...

OBJECTIVE The objective of our study was to evaluate the effect of organ-based tube current modulation and bismuth shielding on image quality and breast radiation dose in women undergoing low-dose chest CT. SUBJECTS AND METHODS From March 2011 through July 2011, 80 women prospectively underwent low-dose chest CT to screen for lung cancer. The patients were randomly assigned to a control group...

Background Diffusion-weighted (DW) echo-planar imaging (EPI) is prone to geometric distortions due B0 inhomogeneities. Both prospective and retrospective approaches have been developed decrease correct such distortions. Purpose The purpose of this work was evaluate the performance reduced-field-of-view (FOV) acquisition distortion correction methods in decreasing artifacts for breast imaging. C...

Breast density has been defined as an important risk factor for the development of breast cancer [1] but the mechanisms of the impact on breast cancer development remain unsolved. One of the main discussions is the definition of breast density. Traditionally breast density is derived by dividing the area of the fibroglandular tissue in the image by the area of the total breast. From a physics p...

We present a method for depth discrimination in parallel-plate, transmission mode, diffuse optical imaging. The method is based on scanning a set of detector pairs, where the two detectors in each pair are separated by a distance δDi along direction δ D i within the x-y scanning plane. A given optical inhomogeneity appears shifted by αi δ D i (with 0≤ αi ≤1) in the images collected with the two...