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- Andersson, Jonas, 1975-, et al.
(författare)
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Estimating Patient Organ Dosewith Computed Tomography: A Review of Present Methodologyand Required DICOM Information : A Joint Report ofAAPM Task Group 246 and the European Federationof Organizations for Medical Physics (EFOMP)
- 2019
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Rapport (refereegranskat)abstract
- The purpose of this report is (1) to summarize the current state of the art in estimating organ doses from CT examinations and (2) to outline a road map for standardized reporting of essential parameters necessary for estimation of organ doses from CT imaging in the DICOM standard. To address these purposes, the report includes a comprehensive discussion of (1) the various metrics, concepts, and methods that may be used to achieve estimates of patient organ dose and (2) the DICOM standard for CT.This Joint Report of the American Association of Physicists in Medicine (AAPM) Task Group 246 and the European Federation of Organizations for Medical Physics (EFOMP) contains three major sections and an appendix. Section 2 (with additional material in the appendix) provides a review of basic CT dosimetry metrics, their uses and limitations in the context of organ dosimetry, and the DICOM information currently associated with parameters that affect CT dose metrics and, consequently, organ dose estimates. Section 3 provides an overview of present and emerging organ dose estimation methods reported in the literature, e.g., for the lens of the eye, breast tissue, colon, and skin. Finally, the report concludes with section 4, which provides a discussion on the sources and magnitudes of uncertainty for different organ dose estimation methods.Ongoing efforts to facilitate routine standardized estimation of patient organ doses from CT are dependent, in large part, on the availability of the DICOM Radiation Dose Structured Report (RDSR), which provides a host of information pertinent to radiation dose calculations. This report, therefore, includes detailed information on DICOM header content in CT images and how it can be used in organ dose estimation. The RDSR markedly expands the abilities of the clinical medical physicist to estimate doses at the patient, device, and protocol level
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| 2. |
- Wallis, Matthew G., et al.
(författare)
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Two-View and Single-View Tomosynthesis versus Full-Field Digital Mammography : High-Resolution X-Ray Imaging Observer Study
- 2012
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 0033-8419 .- 1527-1315. ; 262:3, s. 788-796
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare the diagnostic accuracy of two-dimensional (2D) full-field digital mammography with that of two-view (mediolateral and craniocaudal) and single-view (mediolateral oblique) tomosynthesis in an observer study involving two institutions. Materials and Methods: Ethical committee approval was obtained. All participating women gave informed consent. Two hundred twenty women (mean age, 56.3; range, 40-80 years) with breast density of 2-4 according to American College of Radiology criteria were recruited between November 2008 and September 2009 and underwent standard treatment plus tomosynthesis with a prototype photon-counting machine. After exclusion criteria were met, this resulted in a final test set of 130 women. Ten accredited readers classified the 130 cases (40 cancers, 24 benign lesions, and 66 normal images) using 2D mammography and two-view tomosynthesis. Another 10 readers reviewed the same cases using 2D mammography but single-view tomosynthesis. The multireader, multicase receiver operating characteristic (ROC) method was applied. The significance of the observed difference in accuracy between 2D mammography and tomosynthesis was calculated. Results: For diagnostic accuracy, 2D mammography performed significantly worse than two-view tomosynthesis (average area under ROC curve [AUC] = 0.772 for 2D, AUC = 0.851 for tomosynthesis, P = .021). Significant differences were found for both masses and microcalcification (P = .037 and .049). The difference in AUC between the two modalities of 20.110 was significant (P = .03) only for the five readers with the least experience (<10 years of reading); with AUC of 20.047 for the five readers with 10 years or more experience (P = .25). No significant difference (P = .79) in reader performance was seen when 2D mammography (average AUC = 0.774) was compared with single-view tomosynthesis (average AUC = 0.775). Conclusion: Two-view tomosynthesis outperforms 2D mammography but only for readers with the least experience. The benefits were seen for both masses and microcalcification. No differences in classification accuracy was seen between and 2D mammography and single-view tomosynthesis.
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| 3. |
- Zanca, Federica, et al.
(författare)
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Diagnostic accuracy of digital mammography versus tomosynthesis : effect of radiologists' experience
- 2012
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Ingår i: Medical Imaging 2012. - International Society for Optics and Photonics : SPIE. - 9780819489678 ; , s. 83180-83180
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Konferensbidrag (refereegranskat)abstract
- Purpose: To investigate whether readers' experience affects performance in a study comparing 2D digital mammography (2D) with 2-view (CC and MLO) or 1-view (MLO) tomosynthesis. Materials and Methods: One-hundred-thirty 2D cases were collected from screening assessment and referral clinics; 64 of the cases had verified abnormalities and the remaining were confirmed normal. Two-view tomosynthesis images were obtained from the same patients. Ten accredited readers (5 with ≥ 10 years experience in mammography and 5 with < 10 years) classified the cases in terms of malignancy (rate 0-5), and recall (yes/no), for both modalities. A second experiment was performed with the same cases, with 10 other readers (again 5 experienced / 5 less experienced), but using 2D and 1-view tomosynthesis as the two modalities. The multi-reader-multi-case ROC method was applied and the significance of diagnostic accuracy difference of 2D vs tomosynthesis was calculated, as a function of experience and for each experiment. Recall rate (RR) on malignant and benign cases was also calculated, along with reading time. Results: No significant difference was reached between 2D and 2-view tomosynthesis for experienced readers (pvalue= 0.25); for less experienced readers the p-value was significant (0.03). No significant difference was found between 2D and 1-view tomosynthesis, independent of readers' experience. RR for benign cases decreased for tomosynthesis (for booth 1- and 2-view), independent of experience. Average reading time per case was 79 s (range 65- 91 s) and 134 s (range 119-158 s) for experienced readers; 56 s (range 46-67 s) and 115s (range 97-142 s) for nonexperienced, for 2D and 2-view tomosynthesis respectively. Reading time was 74 s (range 43-98 s) and 99 s (range 73- 117 s) for experienced readers; 74 s (range 62-85 s) and 94 s (range 82-137 s) for non-experienced, for 2D and 1-view tomosynthesis respectively. Conclusions: For experienced readers, there is no evidence of improved diagnostic accuracy when using 2-view or 1- view tomosynthesis, while less experienced readers perform better with 2-view tomosynthesis than 2D images. Tomosynthesis reduces the number of recall of benign cases, without hindering cancer detection.
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