Journal time. The January 2014 issue of Plastic and Reconstructive Surgery Journal had an article on “Accuracy of the Method for Estimating Breast Volume on Three Dimensional Simulated magnetic Resonance Imaging scans in Breast Reconstruction.”
PHEW! Did you get all that? In English what they were thinking is
Can you use MRI to measure how much volume a breast has?
It is a great study actually. They knew women were going to surgery for breast cancer, where their whole breast is removed during mastectomy. So before the surgery they did two things:
- Make a plaster cast of the breast. (This makes a mold which you can fill to figure out the volume of the breast)
- MRI. With 3D simulation. They would circle the breast from 3 different views and then calculate the volume measured using “volume Viewer Plus” by GE healthcare.
Then they did surgery, and the breast was sent to pathology where it is measured.
Things they had to deal with:
- It is a little tricky to do these calculations because breasts are made up of breast tissue and fat, and those have different weights to them. so they used a mean value between the weight for fibroglandular tissue (1 g/cm cubed) and fatty tisssue (0.916 g/cm cubed)
- When trying to figure out how to replace the volume removed, it isn’t a 1:1 ratio- for example when using a TRAM where belly fat is used to replace the fat, it is probably more akin to the weight of fat, not breast tissue
- This still does not account for shape, projection, and changes between lying down and sitting up.
BUT they did find the MRI 3D scans to be useful to measure breast volume. It was more accurate than the plaster casts. (And they would argue more accurate than 2 dimensional photos used with algorithms trying to estimate volume.)
Currently 3D MRI scans are cost prohibitive. But maybe in the future this will be possible for surgical planning.