| 1. |
- Bujila, Robert, et al.
(författare)
-
A validation of SpekPy: A software toolkit for modelling X-ray tube spectra
- 2020
-
Ingår i: Physica medica (Testo stampato). - : Elsevier BV. - 1120-1797 .- 1724-191X. ; 75, s. 44-54
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To validate the SpekPy software toolkit that has been developed to estimate the spectra emitted fromtungsten anode X-ray tubes. The model underlying the toolkit introduces improvements upon a well-knownsemi-empirical model of X-ray emission.Materials and methods: Using the same theoretical framework as the widely-used SpekCalc software, new electronpenetration data was simulated using the Monte Carlo (MC) method, alternative bremsstrahlung crosssectionswere applied, L-line characteristic emissions were included, and improvements to numerical methodsimplemented. The SpekPy toolkit was developed with the Python programming language. The toolkit was validatedagainst other popular X-ray spectrum models (50 to 120 kVp), X-ray spectra estimated with MC (30 to150 kVp) as well as reference half value layers (HVL) associated with numerous radiation qualities from standardlaboratories (20 to 300 kVp).Results: The toolkit can be used to estimate X-ray spectra that agree with other popular X-ray spectrum modelsfor typical configurations in diagnostic radiology as well as with MC spectra over a wider range of conditions.The improvements over SpekCalc are most evident at lower incident electron energies for lightly and moderatelyfiltered radiation qualities. Using the toolkit, estimations of the HVL over a large range of standard radiationqualities closely match reference values.Conclusions: A toolkit to estimate X-ray spectra has been developed and extensively validated for central-axisspectra. This toolkit can provide those working in Medical Physics and beyond with a powerful and user-friendlyway of estimating spectra from X-ray tubes.
|
|
| 2. |
- Omar, A., et al.
(författare)
-
A framework for organ dose estimation in x-ray angiography and interventional radiology based on dose-related data in DICOM structured reports
- 2016
-
Ingår i: Physics in Medicine and Biology. - Stockholm : Institute of Physics Publishing (IOPP). - 0031-9155 .- 1361-6560. ; 61:8, s. 3063-3083
-
Tidskriftsartikel (refereegranskat)abstract
- Although interventional x-ray angiography (XA) procedures involve relatively high radiation doses that can lead to deterministic tissue reactions in addition to stochastic effects, convenient and accurate estimation of absorbed organ doses has traditionally been out of reach. This has mainly been due to the absence of practical means to access dose-related data that describe the physical context of the numerous exposures during an XA procedure. The present work provides a comprehensive and general framework for the determination of absorbed organ dose, based on non-proprietary access to dose-related data by utilizing widely available DICOM radiation dose structured reports. The framework comprises a straightforward calculation workflow to determine the incident kerma and reconstruction of the geometrical relation between the projected x-ray beam and the patient's anatomy. The latter is difficult in practice, as the position of the patient on the table top is unknown. A novel patient-specific approach for reconstruction of the patient position on the table is presented. The proposed approach was evaluated for 150 patients by comparing the estimated position of the primary irradiated organs (the target organs) with their position in clinical DICOM images. The approach is shown to locate the target organ position with a mean (max) deviation of 1.3 (4.3), 1.8 (3.6) and 1.4 (2.9) cm for neurovascular, adult and paediatric cardiovascular procedures, respectively. To illustrate the utility of the framework for systematic and automated organ dose estimation in routine clinical practice, a prototype implementation of the framework with Monte Carlo simulations is included.
|
|
