Diagnostic x-ray dosimetry using Monte Carlo simulation

Ioppolo, J. L.; Price, Roger I.; Tuchyna, T; Buckley, Craig E.

doi:10.1088/0031-9155/47/10/307

Cited by 8 publications

(6 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They provide a better anatomical detail, but are frequently compromised by image noise, partial-volume averaging and imaging artefacts. Despite these drawbacks, it has been well established that voxelised phantoms can be successfully used in a wide range of medical physics applications [5–10]. In this work we describe the development and use of a novel high resolution voxelised head phantom, called here HIGH_RES_HEAD, based on a high resolution CT acquisition of a physical paediatric head phantom (HN715, CIRS).…”

Section: Introductionmentioning

confidence: 99%

Development of a high resolution voxelised head phantom for medical physics applications

et al. 2017

View full text Add to dashboard Cite

Computational anthropomorphic phantoms have become an important investigation tool for medical imaging and dosimetry for radiotherapy and radiation protection. The development of computational phantoms with realistic anatomical features contribute significantly to the development of novel methods in medical physics. For many applications, it is desirable that such computational phantoms have a real-world physical counterpart in order to verify the obtained results. In this work, we report the development of a voxelised phantom, the HIGH_RES_HEAD, modelling a paediatric head based on the commercial phantom 715-HN (CIRS). HIGH_RES_HEAD is unique for its anatomical details and high spatial resolution (0.18 × 0.18 mm2 pixel size). The development of such a phantom was required to investigate the performance of a new proton computed tomography (pCT) system, in terms of detector technology and image reconstruction algorithms. The HIGH_RES_HEAD was used in an ad-hoc Geant4 simulation modelling the pCT system. The simulation application was previously validated with respect to experimental results. When compared to a standard spatial resolution voxelised phantom of the same paediatric head, it was shown that in pCT reconstruction studies, the use of the HIGH_RES_HEAD translates into a reduction from 2% to 0.7% of the average relative stopping power difference between experimental and simulated results thus improving the overall quality of the head phantom simulation. The HIGH_RES_HEAD can also be used for other medical physics applications such as treatment planning studies. A second version of the voxelised phantom was created that contains a prototypic base of skull tumour and surrounding organs at risk.

show abstract

Section: Introductionmentioning

confidence: 99%

Development of a high resolution voxelised head phantom for medical physics applications

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Monte Carlo methods have been used extensively in medical physics for dosimetry [12,13]. Using Monte Carlo techniques enables dosimetry calculations to be performed for any number of imaging conditions, geometries and patient sizes much easier than experimental measurements using phantoms and dosimeters.…”

Section: Discussionmentioning

confidence: 99%

“…Use of a commercially available Monte Carlo computer code (i.e., MCNP) provides a powerful tool to study the absorption and transmission of x-ray energy in phantoms simulating a range of patient sizes [12][13][14]. It is envisioned that a systematic investigation of the relationship between patient dose and diagnostic image quality will permit operators to design imaging protocols that help keep patient doses As Low As Reasonably Achievable (ALARA).…”

Section: Introductionmentioning

confidence: 99%

MCNP simulation of radiation doses distributions in water phantoms simulating interventional radiology patients

Mah

Huda

et al. 2011

SPIE Proceedings

View full text Add to dashboard Cite

Purpose:To investigate the dose distributions in water cylinders simulating patients undergoing Interventional Radiological examinations. Method:The irradiation geometry consisted of an x-ray source, dose-area-product chamber, and image intensifier as currently used in Interventional Radiology. Water cylinders of diameters ranging between 17 and 30 cm were used to simulate patients weighing between 20 and 90 kg. X-ray spectra data with peak x-ray tube voltages ranging from 60 to 120 kV were generated using XCOMP3R. Radiation dose distributions inside the water cylinder (D w ) were obtained using MCNP5. The depth dose distribution along the x-ray beam central axis was normalized to free-in-air air kerma (AK) that is incident on the phantom. Scattered radiation within the water cylinders but outside the directly irradiated region was normalized to the dose at the edge of the radiation field. The total absorbed energy to the directly irradiated volume (E p ) and indirectly irradiated volume (E s ) were also determined and investigated as a function of x-ray tube voltage and phantom size.Results: At 80 kV, the average D w /AK near the x-ray entrance point was 1.3. The ratio of D w near the entrance point to D w near the exit point increased from ~ 26 for the 17 cm water cylinder to ~ 290 for the 30 cm water cylinder. At 80 kV, the relative dose for a 17 cm water cylinder fell to 0.1% at 49 cm away from the central ray of the x-ray beam. For a 30 cm water cylinder, the relative dose fell to 0.1% at 53 cm away from the central ray of the x-ray beam. At a fixed x-ray tube voltage of 80 kV, increasing the water cylinder diameter from 17 to 30 cm increased the E s /(E p +E s ) ratio by about 50%. At a fixed water cylinder diameter of 24 cm, increasing the tube voltage from 60 kV to 120 kV increased the E s /(E p +E s ) ratio by about 12%. The absorbed energy from scattered radiation was between 20-30% of the total energy absorbed by the water cylinder, and was affected more by patient size than x-ray beam energy.Conclusion: MCNP offers a powerful tool to study the absorption and transmission of x-ray energy in phantoms that can be designed to represent patients undergoing Interventional Radiological procedures. This ability will permit a systematic investigation of the relationship between patient dose and diagnostic image quality, and thereby keep patient doses As Low As Reasonably Achievable (ALARA).

show abstract

“…However, study focusing on fluoroscopy has not been found yet. Previous researches were concerned about the impact of scattered radiation on patient dose [10,11,14,16,17] and radiographic image quality [14,18,19] , and the physical properties of radiation [12,20] , but there has not been study on the occupational dose of radiology department staff. Besides, the results obtained in general X-ray study cannot represent validly in fluoroscopy because the properties of these two modalities are different.…”

Section: Clinical Applications Of Fluoroscopy and Its Radiation Dosementioning

confidence: 99%

Simulation, visualization and dosimetric validation of scatter radiation distribution under fluoroscopy settings

Chan

Cheung

et al. 2015

JBEI

View full text Add to dashboard Cite

Objective: This study developed a three-dimensional visualization method for presenting the geometric pattern of the relative dose generated by Monte Carlo (MC) simulation and validated the simulated dose values against the physical measurement. Methods:In fluoroscopy and interventional radiology examinations, relatively high level of occupational dose is delivered to healthcare workers due to prolonged radiation exposure in imaging procedures. As the spatial difference in dose is never negligible, the scatter radiation distribution under fluoroscopic exposures is thus worth investigating. MC simulation is a sophisticated statistical method, which has been widely applied for modeling scatter radiation in general X-ray examination room. However, the application and validation of MC simulation under fluoroscopy setting have not been found yet. In this study, a stack of tissue equivalent slabs were used as the object under fluoroscopic irradiation. EGSnrc-based DOSXYZnrc code was applied to simulate the scatter dose distribution and the physical measurement of radiation dose was performed using an ionization chamber radiation detector.Results: At 19 representative locations taking into account the work area and radiosensitive organs of healthcare workers, the trend compliance of the simulated with the measured dose values was examined using the correlation analysis. A significant monotonic association between the MC simulation and physical measurement of dose values was identified (r s =0.822 and P<.01). At the same horizontal distance from the irradiation axis, it was observed that the air dose was relatively higher at the level of gonad region than at the eye level. Conclusions:The proposed visualization approach illustrates a three dimensional dose simulation in local display density, which arouses the awareness about prolonged radiation exposure in clinical environment. The reliability and validity of the simulation were examined.

show abstract

Diagnostic x-ray dosimetry using Monte Carlo simulation

Cited by 8 publications

References 20 publications

Development of a high resolution voxelised head phantom for medical physics applications

Development of a high resolution voxelised head phantom for medical physics applications

MCNP simulation of radiation doses distributions in water phantoms simulating interventional radiology patients

Simulation, visualization and dosimetric validation of scatter radiation distribution under fluoroscopy settings

Contact Info

Product

Resources

About