Flanagan Henderson (catsupfact2)

MIFG(u)in the vertical direction with regards to the absorbing strips shows a peak at 0.2-0.5 cycles/mm and be a constant value from approximately 1 cycle/mm; whileMIFG(u)in the parallel direction is a constant value with respect to changes in spatial frequency. It is shown thatMIFG(u)could be used to accurately describe the characteristics of a grid under different imaging conditions. We believe that the use of the proposed index could expand the options for optimizing imaging conditions when using grids.Purpose. Auto-contouring (AC) is rapidly becoming standard practice for OAR contouring. However, in clinical practice, clinicians still need to manually check and correct contours. Anomaly detection systems (ADS) can aid the clinical decision process by suggesting which structures require corrections or not, greatly enhancing the value of AC. The purpose of this work is to develop and evaluate a decision support system for detecting anomalies in the case of parotid gland delineations. Head and neck parotid gland delineations (1037 right, 1038 left), were retrieved from the Netherlands Cancer Institute (NKI) database. Morphological and image-based features were extracted from each patient's CT and structure set. An isolation forest model was initially trained on 70% of the data, of which 10% had synthetically generated anomalies and validated on the remaining 30% of clinical data. The ADS was tested on an independent set of 250 patients (Normal 174, Anomalies 76) and on a clinical autocontouring software. Applied to the validation set, the ADS system resulted in area under the curve (AUC) values of 0.93 and 0.94 for the parotid left and right respectively. Image features appeared more important than morphological, but using all features resulted marginally in the best model. Applied to the test set the ADS system reached an accuracy level of 0.83 and 0.81 for the parotid left and right respectively. The ADS was particularly sensitive to uniform expansions/contractions, misplacements, extra/missing slices and anisotropic over-contouring. Anomaly detection can serve as a powerful contour quality assurance tool, especially for cases of organ misplacement and over-contouring. Anomaly detection can serve as a powerful contour quality assurance tool, especially for cases of organ misplacement and over-contouring.Depending on the molar activity of the tracer, the maximal allowable injected activity in mouse brain PET studies can be extremely low in order to avoid receptor saturation. Therefore, a high level of noise can be present in the image. We investigate several dynamic PET reconstruction methods in reduced counts, or equivalently in reduced injected activity, data exemplified in [11C]racloprideBPNDandR1quantification using the simplified reference tissue model (SRTM). We compared independent frame reconstruction (IFR), post-reconstruction HYPR denoising (IFR + HYPR), direct reconstruction using the SRTM model (DIR-SRTM), and the spatial (KERS) and spatiotemporal kernel reconstruction (KERST). Additionally, HYPR denoising of the frames used as features for the calculation of the spatial kernel matrix, was investigated (KERS-HYPR and KERST-HYPR).In vivodata of 11 mice, was used to generate list-mode data for five reduced count levels corresponding to reductions by a factor 4, 8, 12, 16 and 32 (equivalently 2.07, 1s low as 0.26-0.518 MBq. This is desirable in order to maintain the tracer kinetics principle in mouse studies.Many laboratories around the world deal with protection against ionizing radiation. It is a very broad topic, covering both the protection of members of the public and workers exposed to ionizing radiation based on personal or environmental monitoring. The thermoluminescence detectors are commonly used for this purpose, which is accepted in most countries. Inflammation inhibitor The entire process of dose evaluation with such dosimeters can be divided into several steps. Un