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- Meltzer, Carin, et al.
(författare)
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Surveillance of small, solid pulmonary nodules at digital chest tomosynthesis: data from a cohort of the pilot Swedish CArdioPulmonary bioImage Study (SCAPIS)
- 2021
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 62:3, s. 348-359
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Tidskriftsartikel (refereegranskat)abstract
- Background Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomography (CT). Purpose To investigate DTS relative to CT for surveillance of incidental, solid pulmonary nodules. Material and Methods Recruited from a population study, 106 participants with indeterminate solid pulmonary nodules on CT underwent surveillance with concurrently performed CT and DTS. Nodule size on DTS was assessed by manual diameter measurements and semi-automatic nodule segmentations were independently performed on CT. Measurement agreement was analyzed according to Bland-Altman with 95% limits of agreement (LoA). Detection of nodule volume change > 25% by DTS in comparison to CT was evaluated with receiver operating characteristics (ROC). Results A total of 81 nodules (76%) were assessed as measurable on DTS by two independent observers. Inter- and intra-observer LoA regarding change in average diameter were +/- 2 mm. Calculation of relative volume change on DTS resulted in wide inter- and intra-observer LoA in the order of +/- 100% and +/- 50%. Comparing relative volume change between DTS and CT resulted in LoA of -58% to 67%. The area under the ROC curve regarding the ability of DTS to detect volumetric changes > 25% on CT was 0.58 (95% confidence interval [CI] = 0.40-0.76) and 0.50 (95% CI = 0.35-0.66) for the two observers. Conclusion The results of the present study show that measurement variability limits the agreement between DTS and CT regarding nodule size change for small solid nodules.
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| 2. |
- Mirzai, Maral, et al.
(författare)
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The Effect of Dose Reduction on Overall Image Quality in Clinical Chest Tomosynthesis
- 2021
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Ingår i: Academic Radiology. - : Elsevier BV. - 1076-6332. ; 28:10, s. 289-296
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Tidskriftsartikel (refereegranskat)abstract
- Rationale and Objectives: To evaluate the effect of reduction in effective dose on the reproduction of anatomical structures in chest tomosynthesis (CTS). Materials and Methods: Twenty-four CTS examinations acquired at exposure settings resulting in an effective dose of 0.12 mSv for an average sized patient were included in the study. The examinations underwent simulated dose reduction to dose levels corresponding to 32%, 50%, and 70% of the original dose using a previously described and validated method. The image quality was evaluated by five thoracic radiologists who rated the fulfillment of specified image quality criteria in a visual grading study. The ratings for each image quality criterion in the dose-reduced images were compared to the corresponding ratings for the full-dose examinations using visual grading characteristics (VGC) analysis. The area under the resulting VGC curve (AUCVGC) provides a measure of the difference between the ratings, where an AUCVGC of 0.5 indicates no difference. Results: The dose reductions resulted in inferior reproduction of structures compared to the original dose level (AUCVGC <0.5). Structures in the central region of the lung obtained the lowest AUCVGC for each dose level whereas the reproduction of structures in the parenchyma was least affected by the dose reduction. Conclusion: Although previous studies have shown that dose reduction in CTS is possible without affecting the performance of certain clinical tasks, the reproduction of normal anatomical structures is significantly degraded even at small reductions. It is therefore important to consider the clinical purpose of the CTS examinations before deciding on a permanent dose reduction. © 2020 The Association of University Radiologists
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| 3. |
- Söderman, Christina, et al.
(författare)
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Detection of Pulmonary Nodule Growth with Chest Tomosynthesis: A Human Observer Study Using Simulated Nodules
- 2019
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Ingår i: Academic Radiology. - : Elsevier BV. - 1076-6332 .- 1878-4046. ; 26:4, s. 508-518
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Tidskriftsartikel (refereegranskat)abstract
- Chest tomosynthesis has been suggested as a suitable alternative to CT for follow-up of pulmonary nodules. The aim of the present study was to investigate the possibility of detecting pulmonary nodule growth using chest tomosynthesis. Materials and Methods: Simulated nodules with volumes of approximately 100 mm 3 and 300 mm 3 as well as additional versions with increasing volumes were created. The nodules were inserted into images from pairs of chest tomosynthesis examinations, simulating cases where the nodule had either remained stable in size or increased in size between the two imaging occasions. Nodule volume growths ranging from 11% to 252% were included. A simulated dose reduction was applied to a subset of the cases. Cases differing in terms of nodule size, dose level, and nodule position relative to the plane of image reconstruction were included. Observers rated their confidence that the nodules were stable in size or not. The rating data for the nodules that were stable in size was compared to the rating data for the nodules simulated to have increased in size using ROC analysis. Results: Area under the curve values ranging from 0.65 to 1 were found. The lowest area under the curve values were found when there was a mismatch in nodule position relative to the reconstructed image plane between the two examinations. Nodule size and dose level affected the results. Conclusion: The study indicates that chest tomosynthesis can be used to detect pulmonary nodule growth. Nodule size, dose level, and mismatch in position relative to the image reconstruction plane in the baseline and follow-up examination may affect the precision.
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| 4. |
- Söderman, Christina, et al.
(författare)
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Detection of pulmonary nodule growth with dose reduced chest tomosynthesis: a human observer study using simulated nodules
- 2016
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Ingår i: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE. - 1605-7422. ; 9787
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Chest tomosynthesis may be a suitable alternative to computed tomography for the clinical task of follow up of pulmonary nodules. The aim of the present study was to investigate the detection of pulmonary nodule growth suggestive of malignancy using chest tomosynthesis. Previous studies have indicated remained levels of detection of pulmonary nodules at dose levels corresponding to that of a conventional lateral radiograph, approximately 0.04 mSv, which motivated to perform the present study this dose level. Pairs of chest tomosynthesis image sets, where the image sets in each pair were acquired of the same patient at two separate occasions, were included in the study. Simulated nodules with original diameters of approximately 8 mm were inserted in the pairs of image sets, simulating situations where the nodule had remained stable in size or increased isotropically in size between the two different imaging occasions. Four different categories of nodule growth were included, corresponding to a volume increase of approximately 21 %, 68 %, 108 % and 250 %. All nodules were centered in the depth direction in the tomosynthesis images. All images were subjected to a simulated dose reduction, resulting in images corresponding to an effective dose of 0.04 mSv. Four observers were given the task of rating their confidence that the nodule was stable in size or not on a five-level rating scale. This was done both before any size measurements were made of the nodule as well as after measurements were performed. Using Receiver operating characteristic analysis, the rating data for the nodules that were stable in size was compared to the rating data for the nodules simulated to have increased in size. Statistically significant differences between the rating distributions for the stable nodules and all of the four nodule growth categories were found. For the three largest nodule growths, nearly perfect detection of nodule growth was seen. In conclusion, the present study indicates that during optimal imaging conditions and for nodules with diameters of approximately 8 mm that grow fairly symmetrically, chest tomosynthesis performed at a dose level corresponding to that of a lateral chest radiograph can, with high sensitivity, differentiate nodules stable in size from nodules growing at rates associated with fast growing malignant nodules.
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