Visibility of microcalcifications in computed and screen-film mammography

Cowen, Arnold R.; Launders, Jason; Jadav, Mark; Brettle, D S

doi:10.1088/0031-9155/42/8/005

Cited by 47 publications

(35 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is known from several studies that calcifications as small as 130 µm are visible to the human eye [27,28]. With the decrease in pixel size in magnifications and the less attenuated dose (magnification views are obtained without a grid), there is much more information/photons per pixel in more pixels [29].…”

mentioning

confidence: 99%

Impact of Magnification Views on the Characterization of Microcalcifications in Digital Mammography

Fallenberg

Dimitrijevic

Diekmann

et al. 2013

Fortschr Röntgenstr

View full text Add to dashboard Cite

!Purpose: To evaluate the additional benefit of true geometric (air-gap) magnification views for the characterization of microcalcifications in digital mammography. Materials and Methods: After ethical approval, we retrospectively reviewed patient records to identify 100 patients with suspicious microcalcifications (35 malignant, 65 benign) who had a standard digital mammography and an additional digital magnification view in the same projection within three months. All images were obtained using an amorphous silicon-based full-field digital system (Senographe 2000 D, GE Healthcare, Chalfont St. Giles, UK). Images were independently analyzed by six board-certified radiologists. The probability of malignancy was estimated using first standard contact mammography alone (MG) and then mammography in combination with the magnification view (MG+MAG) using a modified Breast Imaging Reporting and Data System (BI-RADS) classification system and a percentage scale. Results were compared using receiver operating characteristic (ROC) analysis. In addition, readers assessed the subjective visibility of the calcifications. Results: For all six readers combined, the area under the curve (AUC) was 0.664 ± 0.052 for MG and 0.813 ± 0.042 for MG + MAG, resulting in a statistically significant improvement of 0.148 ± 0.120. Each reader had a higher AUC for MG + MAG than MG, with the improvement being statistically significant in four of the six readers. In 76.34 % of the cases, MG + MAG resulted in better visibility of calcifications compared with mammography alone. In 33 % slightly more and in 39 % significantly more calcifications were found. Conclusion: Even in digital mammography with the option of using electronic magnification (zoom) at the viewing workstation, true geometric (air-gap) magnification views remain imporThis document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.

show abstract

mentioning

confidence: 99%

Impact of Magnification Views on the Characterization of Microcalcifications in Digital Mammography

Fallenberg

Dimitrijevic

Diekmann

et al. 2013

Fortschr Röntgenstr

View full text Add to dashboard Cite

show abstract

“…Diameters of the deposits varied between 0.2 and 1.0 mm in steps of 0.1 mm, based on the dimensions of calcium deposits found in breast cancer. [27][28][29][30] The volume magnetic susceptibility of each sphere was set to that of calcium phosphate (−11 × 10 −6 , dimensionless SI units), 23 while the value for the surrounding medium was set to the value for water, −9×10 −6 . 3D gradient echo MR magnitude and phase images were simulated separately.…”

Section: A Gradient Echo Magnitude and Phase Image Simulationsmentioning

confidence: 99%

Detection of microcalcifications by characteristic magnetic susceptibility effects using MR phase image cross‐correlation analysis

et al. 2015

View full text Add to dashboard Cite

Purpose: To develop and evaluate a new method for detecting calcium deposits using their characteristic magnetic susceptibility effects on magnetic resonance (MR) images at high fields and demonstrate its potential in practice for detecting breast microcalcifications. Methods: Characteristic dipole signatures of calcium deposits were detected in magnetic resonance phase images by computing the cross-correlation between the acquired data and a library of templates containing simulated phase patterns of spherical deposits. The influence of signal-to-noise ratio and various other MR parameters on the results were assessed using simulations and validated experimentally. The method was tested experimentally for detection of calcium fragments within gel phantoms and calcium-like inhomogeneities within chicken tissue at 7 T with optimized MR acquisition parameters. The method was also evaluated for detection of simulated microcalcifications, modeled from biopsy samples of malignant breast cancer, inserted in silico into breast magnetic resonance imaging (MRIs) of healthy subjects at 7 T. For both assessments of calcium fragments in phantoms and biopsy-based simulated microcalcifications in breast MRIs, receiver operator characteristic curve analyses were performed to determine the cross-correlation index cutoff, for achieving optimal sensitivity and specificity, and the area under the curve (AUC), for measuring the method's performance. Results: The method detected calcium fragments with sizes of 0.14-0.79 mm, 1 mm calcium-like deposits, and simulated microcalcifications with sizes of 0.4-1.0 mm in images with voxel sizes between (0.2 mm) 3 and (0.6 mm) 3 . In images acquired at 7 T with voxel sizes of (0.2 mm) 3 -(0.4 mm) 3, calcium fragments (size 0.3-0.4 mm) were detected with a sensitivity, specificity, and AUC of 78%-90%, 51%-68%, and 0.77%-0.88%, respectively. In images acquired with a human 7 T scanner, acquisition times below 12 min, and voxel sizes of (0.4 mm) 3 -(0.6 mm) 3 , simulated microcalcifications with sizes of 0.6-1.0 mm were detected with a sensitivity, specificity, and AUC of 75%-87%, 54%-87%, and 0.76%-0.90%, respectively. However, different microcalcification shapes were indistinguishable. Conclusions: The new method is promising for detecting relatively large microcalcifications (i.e., 0.6-0.9 mm) within the breast at 7 T in reasonable times. Detection of smaller deposits at high field may be possible with higher spatial resolution, but such images require relatively long scan times. Although mammography can detect and distinguish the shape of smaller microcalcifications with superior sensitivity and specificity, this alternative method does not expose tissue to ionizing radiation, is not affected by breast density, and can be combined with other

show abstract

“…For SF mammography, Desponds et al (1991) reported a minimum visible size in the range of 170-220 μm and Sabol et al (1993) observed a minimum detectable size of 200 μm. Cowen et al (1997) found that the minimum detectable size was 130 μm for both SF and CR mammography. Rong et al (2002) reported that the minimum visible sizes were 110 μm for SF and FP-based digital mammography and 123 μm for CR and CCD-based mammography.…”

Section: Introductionmentioning

confidence: 96%

Receiver operating characteristic analysis for the detection of simulated microcalcifications on mammograms using hardcopy images

et al. 2006

View full text Add to dashboard Cite

The aim of this study was to compare mammography systems based on three different detectors-a conventional screen-film (SF) combination, an a-Si/CsI flat-panel (FP)-based detector, and a charge-coupled device (CCD)-based x-ray phosphor-based detector-for their performance in detecting simulated microcalcifications (MCs). 112-150 μm calcium carbonate grains were used to simulate MCs and were overlapped with a slab phantom of simulated 50% adipose/50% glandular breast tissue-equivalent material referred to as the uniform background. For the tissue structure background, 200-250 μm calcium carbonate grains were used and overlapped with an anthropomorphic breast phantom. All MC phantom images were acquired with and without magnification (1.8X). The hardcopy images were reviewed by five mammographers. A five-point confidence level rating was used to score each detection task. Receiver operating characteristic (ROC) analysis was performed, and the areas under the ROC curves (A z s) were used to compare the performances of the three mammography systems under various conditions. The results showed that, with a uniform background and contact images, the FP-based system performed significantly better than the SF and the CCD-based systems. For magnified images with a uniform background, the SF and the FP-based systems performed equally well and significantly better than the CCD-based system. With tissue structure background and contact images, the SF system performed significantly better than the FP and the CCD-based systems. With magnified images and a tissue structure background, the SF and the CCD-based systems performed equally well and significantly better than the FP-based system. In the detection of MCs in the fibroglandular and the heterogeneously dense regions, no significant differences were found except that the SF system performed significantly better than the CCD-based system in the fibroglandular regions for the contact images.

show abstract

Visibility of microcalcifications in computed and screen-film mammography

Cited by 47 publications

References 39 publications

Impact of Magnification Views on the Characterization of Microcalcifications in Digital Mammography

Impact of Magnification Views on the Characterization of Microcalcifications in Digital Mammography

Detection of microcalcifications by characteristic magnetic susceptibility effects using MR phase image cross‐correlation analysis

Receiver operating characteristic analysis for the detection of simulated microcalcifications on mammograms using hardcopy images

Contact Info

Product

Resources

About