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Quantification of Regional Breast Density in Four Quadrants Using 3D MRI-A Pilot Study.

Fwu PT, Chen JH, Li Y, Chan S, Su MY - Transl Oncol (2015)

Bottom Line: The symmetry of the quadrant BV in the left and right breasts separated by using the nipple alone, or the nipple-centroid line, was compared.Among the four quadrants, PD was the highest in the lower outer and the lowest in the upper outer (significant than the other three) quadrants (P < .05).The reorientation based on the nipple-centroid line improved the left to right quadrant symmetry, and this may provide a better standardized method to measure quantitative quadrant density.

View Article: PubMed Central - PubMed

Affiliation: Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, CA, USA.

No MeSH data available.


Related in: MedlinePlus

Two women showing different degrees of correction after the nipple-centroid reorientation by affine transformation. (A) The right breast of a woman, with the nipple-centroid line close to perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The coronal projection view (shown in the bottom figure) does not change much. (B) The left breast of another woman with a substantial tissue shift after the positional correction. The nipple-centroid line is clearly tilted, far away from perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The location of the breast density also shows a substantial change in the coronal projection view (bottom figure) after the correction.
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f0010: Two women showing different degrees of correction after the nipple-centroid reorientation by affine transformation. (A) The right breast of a woman, with the nipple-centroid line close to perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The coronal projection view (shown in the bottom figure) does not change much. (B) The left breast of another woman with a substantial tissue shift after the positional correction. The nipple-centroid line is clearly tilted, far away from perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The location of the breast density also shows a substantial change in the coronal projection view (bottom figure) after the correction.

Mentions: The simple method described above did not consider the orientation (or tilt) of the breast; therefore, the regional separation done using that way would be heavily dependent on how the breast was positioned into the MR coil (in a prone position). If it was freely hanging with the centroid and the nipple aligning at the same (x, y) location, then the separation could be done on the basis of the nipple alone. However, in most cases, they were not aligned, and a reorientation algorithm could be applied to perform the quadrant separation based on the corrected planes. The centroid, or COM, was calculated from the segmented breast in the 3D space. Depending on the angle of the centroid-nipple line, a simple volume-preserving Affine transformation was applied (see the example shown in Figure 1). The horizontal line through the sternum used to perform the initial cut was defined as the z = 0 plane, and voxels on each plane along the z-axis would be shifted by the amount of {dx, dy} on the L/R direction and superior/inferior direction and no movement along the A/P direction. After the reorientation based on the nipple-centroid line was done, the four quadrants could be separated, and the BV, FV, and PD in each quadrant after correction were calculated. Figure 2 illustrates two cases, one case without much shift and another case with a substantial shift after the correction.


Quantification of Regional Breast Density in Four Quadrants Using 3D MRI-A Pilot Study.

Fwu PT, Chen JH, Li Y, Chan S, Su MY - Transl Oncol (2015)

Two women showing different degrees of correction after the nipple-centroid reorientation by affine transformation. (A) The right breast of a woman, with the nipple-centroid line close to perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The coronal projection view (shown in the bottom figure) does not change much. (B) The left breast of another woman with a substantial tissue shift after the positional correction. The nipple-centroid line is clearly tilted, far away from perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The location of the breast density also shows a substantial change in the coronal projection view (bottom figure) after the correction.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562976&req=5

f0010: Two women showing different degrees of correction after the nipple-centroid reorientation by affine transformation. (A) The right breast of a woman, with the nipple-centroid line close to perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The coronal projection view (shown in the bottom figure) does not change much. (B) The left breast of another woman with a substantial tissue shift after the positional correction. The nipple-centroid line is clearly tilted, far away from perpendicular to the z = 0 axis on the axial projection view (top figure) and the sagittal projection view (middle figure). The location of the breast density also shows a substantial change in the coronal projection view (bottom figure) after the correction.
Mentions: The simple method described above did not consider the orientation (or tilt) of the breast; therefore, the regional separation done using that way would be heavily dependent on how the breast was positioned into the MR coil (in a prone position). If it was freely hanging with the centroid and the nipple aligning at the same (x, y) location, then the separation could be done on the basis of the nipple alone. However, in most cases, they were not aligned, and a reorientation algorithm could be applied to perform the quadrant separation based on the corrected planes. The centroid, or COM, was calculated from the segmented breast in the 3D space. Depending on the angle of the centroid-nipple line, a simple volume-preserving Affine transformation was applied (see the example shown in Figure 1). The horizontal line through the sternum used to perform the initial cut was defined as the z = 0 plane, and voxels on each plane along the z-axis would be shifted by the amount of {dx, dy} on the L/R direction and superior/inferior direction and no movement along the A/P direction. After the reorientation based on the nipple-centroid line was done, the four quadrants could be separated, and the BV, FV, and PD in each quadrant after correction were calculated. Figure 2 illustrates two cases, one case without much shift and another case with a substantial shift after the correction.

Bottom Line: The symmetry of the quadrant BV in the left and right breasts separated by using the nipple alone, or the nipple-centroid line, was compared.Among the four quadrants, PD was the highest in the lower outer and the lowest in the upper outer (significant than the other three) quadrants (P < .05).The reorientation based on the nipple-centroid line improved the left to right quadrant symmetry, and this may provide a better standardized method to measure quantitative quadrant density.

View Article: PubMed Central - PubMed

Affiliation: Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, CA, USA.

No MeSH data available.


Related in: MedlinePlus