# 3D mammography vs. 2D: what the difference means for you

*Both take X-ray pictures of the breast. One takes a stack of thin slices instead of a single flat image. Here is what that changes on the day and afterward.*

September 16, 2026 · Desert Imaging

If you have had a mammogram before, you already know the routine: the compression, the two views of each breast, the technologist stepping behind a screen. A 3D mammogram, also called breast tomosynthesis, feels almost the same from where you are standing. The difference is in what the machine records, and in what the radiologist can see.

## What a 2D mammogram records

A conventional mammogram takes one flat X-ray image of each view. Everything in the breast, front to back, is projected onto that single picture. Dense tissue, glands, and anything unusual all overlap, the way the layers of a stack of paper would if you held it up to a light.

That overlap is the limitation. Normal tissue can hide something small behind it, and normal tissue can also stack up to look like something that is not there.

## What a 3D mammogram records

A 3D mammogram takes a series of low-dose images as the X-ray arm sweeps in a short arc over the breast. The computer assembles them into a stack of thin slices, about a millimeter each. The radiologist scrolls through the slices one at a time, the way you would page through a book instead of looking at the closed cover.

Because each slice shows only the tissue at that depth, overlap stops being a problem. Small findings are easier to see, and shadows created by overlapping normal tissue are easier to recognize for what they are.

## What changes on the day

Almost nothing. Positioning and compression are the same, and the sweep of the arm takes a few seconds per view. The whole appointment is about the same length as a standard mammogram. The radiation dose is similar to a 2D exam and well within the limits set for screening.

## What changes afterward

Two things, and both matter more than the technology.

**Fewer callbacks.** With a 2D exam, a certain number of women are called back for extra pictures because overlapping tissue produced a question mark. 3D imaging resolves many of those questions on the first visit, so fewer people get the phone call, the second appointment, and the days of worry in between.

**Better detection in dense breasts.** Dense breast tissue appears white on a mammogram, and so does a tumor. Slicing the breast into layers helps the radiologist tell the two apart. If your prior reports have described your breasts as dense, ask your doctor about 3D screening specifically.

## Who reads your exam

At Desert Imaging your mammogram is read by one of our four board-certified radiologists, here in El Paso. Dr. Hugo Isuani, one of the four, has spent more than 25 years reading mammograms in this community. The report goes to your doctor and to your patient portal.

## Preparing for your mammogram

- Schedule for the week after your period if you are still menstruating, when breasts are least tender.
- Skip deodorant, powder, and lotion on your chest and underarms that morning. Tiny particles in some products can show up on the images.
- Wear a two-piece outfit so you only need to remove your top.
- Bring your prior mammogram reports or tell us where they were done, so the radiologist can compare.

## Where to get a 3D mammogram in El Paso

Desert Imaging offers 3D mammography at four centers: West on Castellano, East on Lee Trevino, Joe Battle, and Horizon City. All four are open weeknights until 10 p.m. and Saturdays until 9. Call (915) 577-0100 or request an appointment online. If you are due for a screening mammogram and do not have an order, call and ask; we will tell you what applies.