Management of patient doses from digital x-ray chest screening examinations
An anthropomorphic phantom study was carried out in 2013–14 in two hospitals, one located in Russia (Mariinsky Hospital, Saint Petersburg) and the other in Sweden (Skåne University Hospital, Malmö). The aim of the study was to investigate the possibilities to reduce the patient dose from digital X-ray chest screening examinations. The existing chest imaging protocols were adjusted by changing the tube voltage, total filtration and grid in order to determine the most dose-effective combination of the examination parameters. It was possible to achieve up to 50 % dose-area product (DAP) and 30 % effective ...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Vodovatov, A. V., Drozdov, A. A., Telnova, A. U., Bernhardsson, C. Tags: Paper Source Type: research
Skin dose, effective dose and related risk in transcatheter aortic valve implantation (tavi) procedures: is the cancer risk acceptable for younger patients?
The aim of this study was to estimate conversion coefficients for maximum entrance skin dose (MESD) and effective dose (E) for patients undergoing transcatheter aortic valve implantation (TAVI) and to evaluate the risk of exposure-induced cancer death (REID) for prospectively younger patients. Effective doses and risks were estimated for 22 patients using PCXMC whereas MESDs were estimated for a sub-group of 15 patients using Gafchromic film. The estimated conversion coefficients for skin dose [CCS = MESD/dose–area product (DAP)] and E (CCE = E/DAP) were 9.7±1.5 and 0.24±0.02 mSv/Gy cm2, respectively. T...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Karambatsakidou, A., Omar, A., Chehrazi, B., Rück, A., Scherp Nilsson, J., Fransson, A. Tags: Paper Source Type: research
Exposure of the swiss population by radiodiagnostics: 2013 review
This study revealed that the average annual number of examinations is 1.2 per inhabitant, and the associated annual effective dose is 1.4 mSv. It also showed that computed tomography is the most irradiating modality and that it delivers 70 % of the total dose. The annual effective dose per inhabitant registered a 17 % increase in 5 y and is comparable with what was recently reported in neighbouring countries. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Le Coultre, R., Bize, J., Champendal, M., Wittwer, D., Ryckx, N., Aroua, A., Trueb, P., Verdun, F. R. Tags: Paper Source Type: research
Multicentre comparison of patient and detector dose for x-ray-guided embolisations of arteriovenous malformations in the brain
Dosimetric benchmarking at four hospitals was performed to investigate incident entrance dose and dose rate on a phantom, and entrance detector dose and dose rate for protocols that are used in routine clinical practice for complex neuroradiological treatment of arteriovenous malformations (AVMs). Measurements were performed with a head phantom that simulates the attenuation and scattering of the human head for the lateral and posteroanterior (PA) views. For fluoroscopy, the measured incident entrance dose rate and entrance detector dose rate were in the range of 44–172 and 0.3–1.3 μGy s–1, respectivel...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Geleijns, J., Overvelde, M. L., Zweers, D., Mourik, J. E. M. Tags: Paper Source Type: research
The application of diagnostic reference levels for optimisation of x-ray imaging in the uk
The concept of diagnostic reference levels (DRLs) has been introduced to provide standard doses against which hospital patient dose measurements can be compared to evaluate practices. DRLs are defined in terms of measured dose quantities. National DRLs can be derived from surveys of patient doses for common types of examinations in 20–30 large hospitals. The International Commission on Radiological Protection proposes that median doses for each type of examination at every hospital be collated and DRLs based on the third quartile value of the distribution. Once DRLs have been set, periodic audits of patient dose shou...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Martin, C. J. Tags: Paper Source Type: research
Thoracic spine imaging: a comparison between radiography and tomosynthesis using visual grading characteristics
In conclusion, DTS of the thoracic spine appears to be a promising alternative to DR, especially in areas where the problem of overlaying anatomy is accentuated, such as posterior and upper thoracic structures. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Ceder, E., Danielson, B., Kovac, P., Fogel, H., Svalkvist, A., Vikgren, J., Bath, M. Tags: Paper Source Type: research
Influence of the in-plane artefact in chest tomosynthesis on pulmonary nodule size measurements
The aim of the present study was to investigate how the in-plane artefact present in the scan direction around structures in tomosynthesis images should be managed when measuring the size of nodules in chest tomosynthesis images in order to achieve acceptable measurement accuracy. Data from measurements, performed by radiologists, of the longest diameter of artificial nodules inserted in chest tomosynthesis images were used. The association between the measurement error and the direction of the longest nodule diameter, relative to the scan direction, was evaluated using the Kendall rank correlation coefficient. All of the ...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Söderman, C., Johnsson, A. A., Vikgren, J., Norrlund, R. R., Molnar, D., Svalkvist, A., Mansson, L. G., Bath, M. Tags: Paper Source Type: research
Effect of radiation dose level on accuracy and precision of manual size measurements in chest tomosynthesis evaluated using simulated pulmonary nodules
In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Söderman, C., Johnsson, A. A., Vikgren, J., Norrlund, R. R., Molnar, D., Svalkvist, A., Mansson, L. G., Bath, M. Tags: Paper Source Type: research
Visibility of structures of relevance for patients with cystic fibrosis in chest tomosynthesis: influence of anatomical location and observer experience
The aims of this study were to assess the visibility of pulmonary structures in patients with cystic fibrosis (CF) in digital tomosynthesis (DTS) using computed tomography (CT) as reference and to investigate the dependency on anatomical location and observer experience. Anatomical structures in predefined regions of CT images from 21 patients were identified. Three observers with different levels of experience rated the visibility of the structures in DTS by performing a head-to-head comparison with visibility in CT. Visibility of the structures in DTS was reported as equal to CT in 34 %, inferior in 52 % and superior in ...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Meltzer, C., Bath, M., Kheddache, S., Asgeirsdottir, H., Gilljam, M., Johnsson, A. A. Tags: Paper Source Type: research
Overview of a digital tomosynthesis development: new approaches for low-dose chest imaging
Lung cancer has the highest mortality rate among all cancer types, and it has especially high occurrence in Hungary. Low-dose computed tomography (LDCT) has been proved to be a beneficial screening method for lung cancer, decreasing the mortality rate by 20 %. Because of the intensifying fears from X-ray radiation, there is a need to develop other modalities that might work with less radiation and have similar sensitivity in lung nodule finding. Digital tomosynthesis (DTS) may be such a modality that can be a real alternative to LDCT. The goal of this article is to summarise the first results of a Hungarian project for dev...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Horvath, A., Wolf, P., Nagy, J., Kelemen, A., Horvath, G., Hadhazi, D., Horvath, A., Czetenyi, B., Sütto, Z., Szondy, K. Tags: Paper Source Type: research
An analysis of the potential role of chest tomosynthesis in optimising imaging resources in thoracic radiology
In conclusion, the potential role for CTS to substitute other modalities during office hours at a tertiary referral centre may be in the order of 20 and 25 % of performed CXR and chest CT, respectively. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Petersson, C., Bath, M., Vikgren, J., Johnsson, A. A. Tags: Paper Source Type: research
14c bomb-pulse dating and stable isotope analysis for growth rate and dietary information in breast cancer?
The purpose of this study was to perform an initial investigation of the possibility to determine breast cancer growth rate with 14C bomb-pulse dating. Tissues from 11 breast cancers, diagnosed in 1983, were retrieved from a regional biobank. The estimated average age of the majority of the samples overlapped the year of collection (1983) within 3. Thus, this first study of tumour tissue has not yet demonstrated that 14C bomb-pulse dating can obtain information on the growth of breast cancer. However, with further refinement, involving extraction of cell types and components, there is a possibility that fundamental knowled...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Lang, K., Eriksson Stenström, K., Rosso, A., Bech, M., Zackrisson, S., Graubau, D., Mattsson, S. Tags: Paper Source Type: research
Estimates of breast cancer growth rate from mammograms and its relation to tumour characteristics
In conclusion, tumour volume-doubling time as estimated on serial mammography may provide important prognostic information relevant for clinical decision-making. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Förnvik, D., Lang, K., Andersson, I., Dustler, M., Borgquist, S., Timberg, P. Tags: Paper Source Type: research
Simulating local dense areas using pmma to assess automatic exposure control in digital mammography
In conclusion, after some small adaptations, the test is valuable for the assessment of the AEC performance in terms of both SNR and dose. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Bouwman, R. W., Binst, J., Dance, D. R., Young, K. C., Broeders, M. J. M., den Heeten, G. J., Veldkamp, W. J. H., Bosmans, H., van Engen, R. E. Tags: Paper Source Type: research
Influence of localizer and scan direction on the dose-reducing effect of automatic tube current modulation in computed tomography
The purpose of this study was to investigate the influence of the localizer and scan direction on the dose-reducing efficacy of the automatic tube current modulation (ATCM) in computed tomography (CT). Craniocaudal and caudocranial chest CT scans, based on anterior–posterior (AP), posterior–anterior (PA), lateral (LAT) or dual AP/LAT localizers, of an anthropomorphic phantom containing thermoluminescent dosimeters (TLDs), were made on three Siemens systems. TLD readings were converted to lung and thyroid doses. A second dose estimation was performed based on Monte Carlo simulations. In addition, the ATCM behavi...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Franck, C., Bacher, K. Tags: Paper Source Type: research
