Search

Your search keyword '"Timberg, Pontus"' showing total 198 results
Start Over Author "Timberg, Pontus"
198 results on '"Timberg, Pontus"'

3. The Characteristics of Malignant Breast Tumors Imaged Using a Prototype Mechanical Imaging System as an Adjunct to Mammography

Author

Dustler, Magnus, Förnvik, Daniel, Timberg, Pontus, Petersson, Hannie, Tingberg, Anders, Zackrisson, Sophia, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Tingberg, Anders, editor, Lång, Kristina, editor, and Timberg, Pontus, editor

Published
2016
Full Text
View/download PDF

4. Breast Density Assessment Using Breast Tomosynthesis Images

Author

Timberg, Pontus, Fieselmann, Andreas, Dustler, Magnus, Petersson, Hannie, Sartor, Hanna, Lång, Kristina, Förnvik, Daniel, Zackrisson, Sophia, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Tingberg, Anders, editor, Lång, Kristina, editor, and Timberg, Pontus, editor

Published
2016
Full Text
View/download PDF

6. Image Quality of Thick Average Intensity Pixel Slabs Using Statistical Artifact Reduction in Breast Tomosynthesis

Author

Dustler, Magnus, Timberg, Pontus, Tingberg, Anders, Zackrisson, Sophia, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Kobsa, Alfred, editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Weikum, Gerhard, editor, Fujita, Hiroshi, editor, Hara, Takeshi, editor, and Muramatsu, Chisako, editor

Published
2014
Full Text
View/download PDF

7. BIRADS Classification in Breast Tomosynthesis Compared to Mammography and Ultrasonography

Author

Tingberg, Anders, Andersson, Ingvar, Ikeda, Debra M, Ruschin, Mark, Svahn, Tony, Timberg, Pontus, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, and Krupinski, Elizabeth A., editor

Published
2008
Full Text
View/download PDF

15. Distribution of pressure on the breast in mammography using flexible and rigid compression plates: implications on patient handling.

Author

Dustler, Magnus, Förnvik, Daniel, Timberg, Pontus, Zackrisson, Sophia, and Muller, Serge

Subjects
MAMMOGRAMS, PRESSURE sensors, CONFIDENCE intervals
Abstract

Background: Breast compression in mammography is important but is a source of discomfort and has been linked to screening non-attendance. Reducing compression has little effect on breast thickness, and likely little effect on image quality, due to force being absorbed in the stiff juxta thoracic area instead of in the central breast. Purpose: To investigate whether a flexible compression plate can redistribute force to the central breast and whether this affects perceived pain. Material and Methods: Twenty-eight women recalled from mammography screening were compressed with flexible and rigid plates while retaining force and positioning, 15 in the craniocaudal (CC) view and 13 in the mediolateral oblique (MLO) view. Pressure distribution was continuously measured using pressure sensors. Results: The flexible plate showed greater mean breast pressure in both views: 2.8 versus 2.3 kPa for CC (confidence interval [CI] = 0.2–0.8) and 1.0 versus 0.5 kPa for MLO (CI = 0.2–0.6). The percentage of applied force distributed to the breast was significantly higher with the flexible plate, both on CC (36% vs. 22%, CI = 1–11) and MLO (30% vs. 14%, CI = 4–13). Conclusion: The flexible plate redistributes pressure to the central breast, achieving a better compression, particularly in the MLO view, though much applied force is still applied to the juxta thoracic region. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

18. Inter‐laboratory comparison of channelized hotelling observer computation

Author

Ba, Alexandre, primary, Abbey, Craig K., additional, Baek, Jongduk, additional, Han, Minah, additional, Bouwman, Ramona W., additional, Balta, Christiana, additional, Brankov, Jovan, additional, Massanes, Francesc, additional, Gifford, Howard C., additional, Hernandez‐Giron, Irene, additional, Veldkamp, Wouter J. H., additional, Petrov, Dimitar, additional, Marshall, Nicholas, additional, Samuelson, Frank W., additional, Zeng, Rongping, additional, Solomon, Justin B., additional, Samei, Ehsan, additional, Timberg, Pontus, additional, Förnvik, Hannie, additional, Reiser, Ingrid, additional, Yu, Lifeng, additional, Gong, Hao, additional, and Bochud, François O., additional

Published
2018
Full Text
View/download PDF

21. Learning density independent texture features

Author

Tingberg, Anders, Lång, Kristina, Timberg, Pontus, Kallenberg, Michiel Gijsbertus J., Nielsen, Mads, Holland, Katharina, Karssemeijer, Nico, Igel, Christian, Lillholm, Martin, Tingberg, Anders, Lång, Kristina, Timberg, Pontus, Kallenberg, Michiel Gijsbertus J., Nielsen, Mads, Holland, Katharina, Karssemeijer, Nico, Igel, Christian, and Lillholm, Martin

Published
2016

22. ESTIMATES OF BREAST CANCER GROWTH RATE FROM MAMMOGRAMS AND ITS RELATION TO TUMOUR CHARACTERISTICS.

Author

Förnvik, Daniel, Lång, Kristina, Andersson, Ingvar, Dustler, Magnus, Borgquist, Signe, Timberg, Pontus, Förnvik, Daniel, Lång, Kristina, Andersson, Ingvar, Dustler, Magnus, Borgquist, Signe, and Timberg, Pontus

Abstract

This study aimed to investigate the growth rate of 31 consecutive invasive breast cancers based on volume measures on at least two serial mammograms and its relation to histopathological findings. The average tumour volume-doubling time in all invasive breast cancer subtypes was 282 d (range 46-749 d). Grade III breast cancers had a significantly shorter average tumour volume-doubling time of 105 d (range 46-157 d) compared with Grade I and II tumours (average of 296 d, range 147-531 d and average of 353 d, range 139-749 d, respectively) (p = 0.002). Multiple linear regression identified that tumour volume-doubling time was positively associated with patient age, histological grade and progesterone receptor expression and inversely associated with axillary lymph node involvement, human epidermal growth factor receptor 2 and Ki-67 expression (p < 0.001). In conclusion, tumour volume-doubling time as estimated on serial mammography may provide important prognostic information relevant for clinical decision-making.

Published
2016

26. Breast tomosynthesis image volumes are read more efficiently when displayed horizontally

Author

Timberg, Pontus

Subjects
Observer performance, Perception image, Eyes, Breast, Imaging sequences, Image manipulation / Reconstruction, Mammography, CT
Abstract

Purpose Methods and Materials Results Conclusion References Personal Information, Purpose: At breast tomosynthesis (BT) image volume readings, thin slices of the breast are generally viewed in a cine-loop or/and a manual free-scroll procedure. BT yields an extensive image set compared to 2D mammography and there is a need to minimize...

Published
2012
Full Text
View/download PDF

27. Breast Tomosynthesis: Aspects on detection and perception of simulated lesions

Author

Timberg, Pontus

Subjects
Radiology, Nuclear Medicine and Medical Imaging
Abstract

The aim of this thesis was to investigate aspects on detectability of simulated lesions (microcalcifications and masses) in digital mammography (DM) and breast tomosynthesis (BT). Perception in BT image volumes were also investigated by evaluating certain reading conditions. The first study concerned the effect of system noise on the detection of masses and microcalcification clusters in DM images using a free-response task. System noise has an impact on image quality and is related to the dose level. It was found to have a substantial impact on the detection of microcalcification clusters, whereas masses were relatively unaffected. The effect of superimposed tissue in DM is the major limitation hampering the detection of masses. BT is a three-dimensional technique that reduces the effect of superimposed tissue. In the following two studies visibility was quantified for both imaging modalities in terms of the required contrast at a fixed detection performance (92% correct decisions). Contrast detail plots for lesions with sizes 0.2, 1, 3, 8 and 25 mm were generated. The first study involved only an in-plane BT slice, where the lesion centre appeared. The second study repeated the same procedure in BT image volumes for 3D distributed microcalcification clusters and 8 mm masses at two dose levels. Both studies showed that BT needs substantially less contrast than DM for lesions above 1 mm. Furthermore, the contrast threshold increased as the lesion size increased for both modalities. This is in accordance with the reduced effect of superimposed tissue in BT. For 0.2 mm lesions, substantially more contrast was needed. At equal dose, DM was better than BT for 0.2 mm lesions and microcalcification clusters. Doubling the dose substantially improved the detection in BT. Thus, system noise has a substantial impact on detection. The final study evaluated reading conditions for BT image volumes. Four viewing procedures were assessed: free scroll browsing only or combined with initial cine loops at frame rates of 9, 14 and 25 fps. They were viewed on a wide screen monitor placed in vertical or horizontal positions. A free-response task and eye tracking were utilized to record the detection performance, analysis time, visual attention and search strategies. Improved reading conditions were found for horizontally aligned BT image volumes when using free scroll browsing only or combined with a cine loop at the fastest frame rate.

Published
2011

37. VALIDATION OFA SIMULATION PROCEDURE FOR GENERATING BREAST TOMOSYNTHESIS PROJECTION IMAGES.

Author

Petersson, Hannie, Warren, Lucy M., Tingberg, Anders, Dustler, Magnus, and Timberg, Pontus

Subjects
TOMOSYNTHESIS, IMAGE quality in imaging systems, MONTE Carlo method, BREAST cancer, MEDICAL protocols
Abstract

In order to achieve optimal diagnostic performance in breast tomosynthesis (BT) imaging, the parameters of the imaging chain should be evaluated. For the purpose of such evaluations, a simulation procedure based on the Monte Carlo code system Penelope and the geometry of a Siemens BT system has been developed to generate BT projection images. In this work, the simulation procedure is validated by comparing contrast and sharpness in simulated images with contrast and sharpness in real images acquired with the BT system. The results of the study showed a good agreement of sharpness in real and simulated reconstructed image planes, but the contrast was shown to be higher in the simulated compared with the real projection images. The developed simulation procedure could be used to generate BT images, but it is of interest to further investigate how the procedure could be modified to generate more realistic image noise and contrast. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

38. Potential for lower doses in digital mammograph Tumor detection in hybrid images using a dose reduction simulation method

Author

Timberg, Pontus and Timberg, Pontus

Abstract

Purpose: To determine how image quality linked to tumor detection is affected by reducing the absorbed dose to 50% and 30% of standard dose levels, i.e. an average glandular dose of 1.26 mGy for a standard breast according to European guidelines. Material and methods: Tumors were computer simulated and inserted into 40 out of 90 normal, unprocessed images acquired from the screening department at Malmö University Hospital using a Siemens Mammomat Novation full-field digital mammography unit. All 90 images were then dose-reduced by adding simulated quantum noise to represent images acquired at 50% and 30% of the original dose levels set by the automatic exposure control (AEC). This yielded 270 images that were subsequently processed for final display. One radiologist and 3 physicists participated in this study in which they searched for and marked the positions of the tumors and the degree of suspicion. The analysis of results were carried out using the jackknife free-response ROC (JAFROC) method together with analysis of variance (ANOVA).Results: In the tumor detection study, the cumulative figure of merits (FOM’s) calculated from JAFROC scoring were 0.61, 0.66 and 0.67 for the 100%, 50%, and 30% dose levels, respectively. ANOVA revealed an F-stat and p-value of 1.90 and 0.15, respectively, indicating no statistical difference in tumor detection between any two pairs of scores.Conclusion: For the simulated tumors used in this experiment, there was no significant change in detection by increasing quantum noise, indicating a potential for dose reduction. Further studies could involve using different shaped masses or microcalcifications, different processing algorithms and different window/level settings.

Published
2006

Catalog

Books, media, physical & digital resources
See catalog results