What is a Tomo anyways?

Who or what is tomo, and why should I care?

If you're a woman, by now, chances are you have heard about 3D mammography or breast tomosynthesis, (a.k.a. tomo for short). Maybe you've had one, maybe you're still putting it off, or not quite old enough, but regardless, tomo isn't going away. And that's probably a good thing.

A mammogram is a tool that we use to screen for breast cancer. "Screening" is an important concept, and I'll discuss it further in a future blog post, but the key message is that we are looking for a disease before the disease has made itself apparent. That's all a screening test does: in breast cancer, the mammogram tries to find breast cancer before it has become a lump that someone would be able to feel with their fingers. (Mammograms also help us determine if lumps that we can feel are something that we need to worry about, but that is technically called a diagnostic mammogram.)

Conventional mammograms are essentially two x-rays of each breast and thats why "the girls" get so squished during the study. The tissue needs to be spread out so your radiologist can make an interpretation. There are always going to be some women whose breast tissue showed something suspicious and those women will come back for additional pictures: this is what is known as a call-back. A lot of call-back mammograms show that there is actually nothing suspicious going on. But, you can imagine (or you already know) that call-backs are not fun.

With 3D mammography, the breast is held still (with much less squishing) and the x-ray camera takes pictures from multiple angles as the tube moves in an arc. The images are sent to a computer where the "synthesis" occurs and produces a 3 dimensional image of the breast.

Are there benefits of 3D mammography? Is it just a bunch of fancy stuff with no actual impact? For the most part, 3D is preferable to conventional digital mammography. The studies comparing the two have shown fewer call-backs (up to 40%) and better detection of invasive cancers when 3D mammography is used.

The downside: 3D mammograms use more radiation and they technically cost more to complete after accounting for the cost of the equipment and the additional time and expertise needed to interpret the images. Medicare does cover tomosynthesis, but private insurance carriers vary when it comes to how and what they cover of the added tomosynthesis costs. Its always best to check with your health plan if you have concerns.

Luckily, the women of Sonoma Valley now have access to brand new tomosynthesis equipment that can capture images of the highest quality and our radiologists are also highly experienced at reading 3D images because of their work at Marin General Hospital. Its a win-win situation, right here close to home.

For more information, or to schedule YOUR mammogram, call Sonoma Valley Hospital's Medical Imaging Department at 707-935-5234. (And FYI, all women's imaging services (mammograms and DEXA scans) moved back to the main hospital building at 347 Andrieux earlier this year.)