Dr. Angelica Svalkvist Profile

Dr. Angelica Svalkvist

at Sahlgrenska Univ Hospital

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Publications (10)

SPIE Journal Paper | 28 October 2024 Open Access

Lung nodule localization and size estimation on chest tomosynthesis

Micael Oliveira Diniz, Mohammad Khalil, Erika Fagman, Jenny Vikgren, Faiz Haj, Angelica Svalkvist, Magnus Båth, Åse Allansdotter Johnsson

JMI, Vol. 12, Issue S1, S13007, (October 2024) https://doi.org/10.1117/12.10.1117/1.JMI.12.S1.S13007

KEYWORDS: Lung, Computed tomography, Tomosynthesis, Chest, Computer aided detection, Visualization, Visibility, Statistical analysis, X-ray computed tomography, Radiology

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SPIE Journal Paper | 14 September 2024 Open Access

Breathing motion compensation in chest tomosynthesis: evaluation of the effect on image quality and presence of artifacts

Maral Mirzai, Jenny Nilsson, Patrik Sund, Rauni Rossi Norrlund, Micael Oliveira Diniz, Bengt Gottfridsson, Ida Häggström, Åse Johnsson, Magnus Båth, Angelica Svalkvist

JMI, Vol. 12, Issue S1, S13004, (September 2024) https://doi.org/10.1117/12.10.1117/1.JMI.12.S1.S13004

KEYWORDS: Image quality, Chest, Tomosynthesis, Anatomy, Image restoration, X-ray computed tomography, Computed tomography, Statistical analysis, Motion analysis, Chest imaging

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PurposeChest tomosynthesis (CTS) has a relatively longer acquisition time compared with chest X-ray, which may increase the risk of motion artifacts in the reconstructed images. Motion artifacts induced by breathing motion adversely impact the image quality. This study aims to reduce these artifacts by excluding projection images identified with breathing motion prior to the reconstruction of section images and to assess if motion compensation improves overall image quality.ApproachIn this study, 2969 CTS examinations were analyzed to identify examinations where breathing motion has occurred using a method based on localizing the diaphragm border in each of the projection images. A trajectory over diaphragm positions was estimated from a second-order polynomial curve fit, and projection images where the diaphragm border deviated from the trajectory were removed before reconstruction. The image quality between motion-compensated and uncompensated examinations was evaluated using the image quality criteria for anatomical structures and image artifacts in a visual grading characteristic (VGC) study. The resulting rating data were statistically analyzed using the software VGC analyzer.ResultsA total of 58 examinations were included in this study with breathing motion occurring either at the beginning or end (n=17) or throughout the entire acquisition (n=41). In general, no significant difference in image quality or presence of motion artifacts was shown between the motion-compensated and uncompensated examinations. However, motion compensation significantly improved the image quality and reduced the motion artifacts in cases where motion occurred at the beginning or end. In examinations where motion occurred throughout the acquisition, motion compensation led to a significant increase in ripple artifacts and noise.ConclusionsCompensation for respiratory motion in CTS by excluding projection images may improve the image quality if the motion occurs mainly at the beginning or end of the examination. However, the disadvantages of excluding projections may outweigh the benefits of motion compensation.

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Proceedings Article | 24 March 2016 Paper

Detection of pulmonary nodule growth with dose reduced chest tomosynthesis: a human observer study using simulated nodules

Christina Söderman, Åse Johnsson, Jenny Vikgren, Rauni Rossi Norrlund, David Molnar, Maral Mirzai, Angelica Svalkvist, Lars Gunnar Månsson, Magnus Båth

Proceedings Volume 9787, 97870P (2016) https://doi.org/10.1117/12.2216950

KEYWORDS: Chest, Radiology, Radiography, Monte Carlo methods, Medical imaging, Optical spheres, Chest imaging, Statistical analysis, Sensors, Software development

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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.

Proceedings Article | 18 March 2015 Paper

An attempt to estimate out-of-plane lung nodule elongation in tomosynthesis images

Artur Chodorowski, Jonathan Arvidsson, Christina Söderman, Angelica Svalkvist, Åse Johnsson, Magnus Båth

Proceedings Volume 9412, 94122J (2015) https://doi.org/10.1117/12.2079901

KEYWORDS: Signal attenuation, Lung, Chest, X-rays, Reconstruction algorithms, Tissues, Sensors, Computer simulations, Radiology, Spatial resolution

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Proceedings Article | 19 March 2014 Paper

Comparison of different approaches of estimating effective dose from reported exposure data in 3D imaging with interventional fluoroscopy systems

Angelica Svalkvist, Jonny Hansson, Magnus Båth

Proceedings Volume 9033, 90333Z (2014) https://doi.org/10.1117/12.2043469

KEYWORDS: Fluoroscopy, Imaging systems, Stereoscopy, X-rays, 3D image processing, Image acquisition, 3D acquisition, Monte Carlo methods, Chest, X-ray imaging

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Proceedings Article | 17 March 2011 Paper

Investigation of the effect of varying scatter-to-primary ratios on nodule contrast in chest tomosynthesis

Angelica Svalkvist, Gustaf Ullman, Markus Håkansson, David Dance, Michael Sandborg, Gudrun Alm Carlsson, Magnus Båth

Proceedings Volume 7961, 79615Y (2011) https://doi.org/10.1117/12.873173

KEYWORDS: Monte Carlo methods, Chest, Optical spheres, Lung, Sensors, Signal detection, Medicine, Computed tomography, Photons, Physics

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Proceedings Article | 3 March 2011 Paper

Extended analysis of the effect of learning with feedback on the detectability of pulmonary nodules in chest tomosynthesis

Sara Asplund, Åse Johnsson, Jenny Vikgren, Angelica Svalkvist, Marianne Boijsen, Valeria Fisichella, Agneta Flinck, Åsa Wiksell, Jonas Ivarsson, Hans Rystedt, Lars Gunnar Månsson, Susanne Kheddache, Magnus Båth

Proceedings Volume 7966, 796609 (2011) https://doi.org/10.1117/12.873059

KEYWORDS: Chest, Statistical analysis, Computed tomography, Radiology, Medicine, Radiography, Receivers, Medical imaging, Picture Archiving and Communication System, Electronic filtering

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Proceedings Article | 14 March 2009 Paper

Investigation of the dosimetry of chest tomosynthesis

Angelica Svalkvist, Sara Zachrisson, Lars Gunnar Månsson, Magnus Båth

Proceedings Volume 7258, 72585X (2009) https://doi.org/10.1117/12.810256

KEYWORDS: Chest, Radiography, X-rays, Sensors, Monte Carlo methods, Medicine, X-ray detectors, Diagnostics, Spatial resolution, Quantum efficiency

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Proceedings Article | 13 March 2009 Paper

Evaluation of chest tomosynthesis for the detection of pulmonary nodules: effect of clinical experience and comparison with chest radiography

Sara Zachrisson, Jenny Vikgren, Angelica Svalkvist, Åse Johnsson, Marianne Boijsen, Agneta Flinck, Lars Gunnar Månsson, Susanne Kheddache, Magnus Båth

Proceedings Volume 7263, 72630Z (2009) https://doi.org/10.1117/12.811099

KEYWORDS: Chest, Radiography, Statistical analysis, Radiology, Computed tomography, Receivers, Medicine, Medical imaging, Electronic filtering, Sensors

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Proceedings Article | 13 March 2009 Paper

ViewDEX 2.0: a Java-based DICOM-compatible software for observer performance studies

Markus Håkansson, Sune Svensson, Sara Zachrisson, Angelica Svalkvist, Magnus Båth, Lars Gunnar Månsson

Proceedings Volume 7263, 72631G (2009) https://doi.org/10.1117/12.811511

KEYWORDS: Java, Zoom lenses, Visualization, X-ray imaging, Medical imaging, Radiology, Digital x-ray imaging, X-rays, Image registration, X-ray computed tomography

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