Introduction The relationship between noise and detectable spatial resolution is described by the Rose Model: the differentiation of a single voxel from the noise background requires a minimum signal-to-noise ratio (SNR) per voxel of 4 (1,2). This model has been widely used as a guide in x-ray imaging. This study assesses its implication for MRI and develops a guideline forkspace sampling. In k...

Objective: Different categories are available for estimating of radiation dose. Radioisotopes with the same energy and almost the same physical properties have similar effects. Monte Carlo technique is a computerized method based on mathematical simulation of physical processes. The main purpose of this study is to show that beta particles are not able to penetrate deep into the water. also dif...

Background Accurate assessment of relative reductions in regional myocardial blood flow (MBF) is clinically important in identifying haemodynamically significant coronary artery disease. First-pass perfusion magnetic resonance imaging allows for a non-invasive and radiation free quantification of MBF. One of the advantages of MR perfusion over nuclear medicine techniques is better spatial resol...

designed in [2] for unobstructed Glu and Gln detection with chosen (TE, TM) regions in white boxes for phantom experiments. Fig. 2. In vitro STEAM spectra of Glu and Gln acquired at (72ms, 06 ms) and (84 ms, 58 ms) at 3T and multiplied with a filter to render them representative of typical in vivo line widths. Fig. 3. In vivo STEAM spectra acquired from a voxel including the ACC of a healthy vo...

objective: different categories are available for estimating of radiation dose. radioisotopes with the same energy and almost the same physical properties have similar effects. monte carlo technique is a computerized method based on mathematical simulation of physical processes. the main purpose of this study is to show that beta particles are not able to penetrate deep into the water. also dif...

Annually, many people are irradiated for diagnostic and therapeutic purposes. Assessment of radiation dose and its related risks to patients are important issues in radiation protection dosimetry. The complex mathematical calculations of the absorbed and effective doses are now done with computers. The calculations are performed with the help of anthropomorphic computational models of human bod...

Purpose. – The aim of the present study was to quantitatively assess the performance of a block matching-based automatic registration algorithm integrated within the commercial treatment planning system designated ISOgrayTM from Dosisoft. The accuracy of the process was evaluated by a phantom study on computed tomography (CT), magnetic resonance (MR) and positron emission tomography (PET) image...

PURPOSE To describe our approach to mapping the functional information provided by single photon emission computed tomography (SPECT) onto the anatomic template provided by MR, and to determine both the number of markers required to achieve accuracy and the impact of voxel shape on accuracy. METHODS Point-to-point iterative minimization using externally fixed fiducial markers was involved and...