Medical imaging system simulators are tools that provide a means to evaluate system architecture and create artificial image sets that are appropriate for specific applications. We have modified SIMRI, a Bloch equation-based magnetic resonance image simulator, in order to successfully generate high-resolution 3D MR images of the Montreal brain phantom using Blue Gene/L systems. Results show tha...

choline, glutamate and inositol (32x32 matrix) with 2-fold SENSE acceleration. Fig.3 Fully sampled PEPSI maps of non-suppressed water (64x64 matrix) and metabolite maps of NAA, creatine, choline, glutamate and inositol (32x32 matrix), acquired in 8.5 min with 0.63 cc voxel size. Fig.1 Non-water-suppressed PEPSI maps on phantom at 7 T show good reconstruction performance for up to 4-fold acceler...

Fig.4: Temperature changes of the hottest voxel in 2D cheese experiments. While the conventional sequence (magenta) underestimated temperatures due to the presence of fat, the present method (green) suppressed fat and reduced imaging time by 8-fold. Green line is the result of temporal average over a sliding window of 8 time frames. Fig.2: Excitation profile in a cheese phantom. The distance be...

Fig.4: Temperature changes of a cheese phantom at the hottest voxel during FUS heating experiments. While measurements using GE fast gradient-echo sequence are echo time-dependent (a), the measurements using 2DRF pulse for fat suppression are very similar (b). With excitation pattern of Fig.2d, both fat suppression and 2D excitation were achieved, resulting in improvement in temporal resolution...

In vivo measurement of actinides activity in human skull is a valuable technique of internal dosimetry. Many articles were published on calibrations and some new facts were found. The most important finding was that the relation of measured head size and size of a calibration phantom has notable effect on measured activity; however real impact depends on the detectors geometry. Still opened and...

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...

Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been developed in the first part of this study using 3D animation software and anatomical atlases to replace the image-based FAX06 and the MAX06 voxel phantoms. 3D modelling methods allow for phantom development independent from medical images of patients, volunteers or cadavers. The second pa...

Currently, there is very limited ability to measure the temperature of the brain, but a direct technique for its estimation in vivo could improve the detection of patients at risk of temperature-related brain damage, help in the diagnosis of stroke and tumour, and provide useful information on the mechanisms of thermoregulation of the brain. In this article, new calibrations in vitro of MRS the...

Accurate knowledge of ionizing radiation dose from cone-beam CT (CBCT) imaging in radiotherapy is important to allow concomitant risks to be estimated and for justification of imaging exposures. This study uses a Monte Carlo CBCT model to calculate imaging dose for a wide range of imaging protocols for male and female patients. The Elekta XVI CBCT system was modeled using GATE and simulated dos...

PURPOSE To develop an easily-implemented technique with free publicly-available analysis software to measure the modulation transfer function (MTF) and noise-power spectrum (NPS) of a clinical computed tomography (CT) system from images acquired using a widely-available and standardized American College of Radiology (ACR) CT accreditation phantom. METHODS Images of the ACR phantom were acquir...