Breast MRI at 3T (3 Tesla Magnetic Resonance Imaging). A recent publication by the ACR (American College of Radiology) said that 3T MRI was 100% sensitive in their study of 443 patients with high risk of breast cancer. It found 66/66 cancers. Ultrasound was 85% sensitive but is very operator dependent. In one facility here in Delaware - mammography and ultrasound missed 5 breast lesions. The main lesion was called a scar. 3T MRI found them all. You really need to know about 3T MRI if you are worried about a breast mass. 3T MRI is MRI done with a more powerful magnet. Tesla is a unit of “magnetic field” and experts speak in terms of higher or lower “field strength.” Simply put, the stronger the magnet (“higher” the field strength), the better the images. 3T-MRI takes better and sharper pictures and does it much faster than weaker magnets. 3T-MRI is the best way to do breast MRI. Get the best - get a 3T BREAST MRI STUDY.
There are several reasons why Breast MRI is better at 3T. It has higher “signal to noise,” which generates more detailed images (crucial for seeing tumor borders and ductal anatomy) and higher resolution, which results in clearer/sharper images (vital for detecting subtle cancers and even less subtle cancers in earlier stages). 3T images deal far better with fat saturation of the breasts and are twice as sensitive to contrast enhancement.
3T MRI has twice the signal to noise of a 1.5T MRI—and up to ten times that of most OPEN MRI scanners.[1] We have a case of over 15 tumors completely missed on an OPEN MRI system. Simply put, “signal to noise” is a measure of the elements used to create MRI images. It’s a bit like talking about the number of “pixels” in a digital camera. The more pixels (higher the signal to noise), the clearer and more detailed the image. Theoretically, a 3T scan could be done four times more quickly than at 1.5T (and up to 100 times faster than with an OPEN MRI). In practice, however, we prefer to say that 3T scans twice as fast—already a great improvement. The average patient nowadays can’t seem to stay still for as long as they used to. Producing a high quality scan in half the normal time greatly increases the odds of getting a good image while, at the same time, reducing the likelihood of having to repeat the scan because the patient moved. At MRI Consultants, our breast studies create approximately 1700 images in half an hour. This is incredible—twice as many images as any other scanner in the same amount of time.
One very important issue related to Breast MRI is how the fat in the breast is seen by the MRI scanner. Both fat and cancer show up as bright white. We deal with this by using “fat saturation” and “contrast.” Fat saturation is actually how the MRI scanner uses radio waves to exclude the white of fatty tissue from the image while leaving cancer cells visible. Contrast (Prohance TM) is essentially a dye that is injected into the bloodstream to highlight tumors and other areas of high blood flow. It makes a tumor appear much brighter and more detailed. As 3T MRI is much better at fat saturation than weaker MRI scanners—and twice as sensitive to the effects of contrast—the stronger scanner is much better at detecting breast cancer. We are currently (10/21/08) the only facility to use the safest contrast in Delaware. Prohance costs more money and it might be useful for the patient to know that at our facility the PATIENT IS NUMBER ONE. We pay more for safer contrast for you (our patient).
3T MRI is also much more sensitive to tumor margin detail, which greatly increases the chances of detecting cancers. Cancers typically have irregular margins but scanners with lower resolution smooth out these margins, making an irregular lesion appear more rounded and, therefore, less likely to be properly diagnosed. Higher resolution also impacts on our ability to see whether lesions extend into ducts.
As I’ve already said, 3T MRI scanners create images more quickly than weaker magnets. They can scan contiguous slices that are 1 mm thin, allowing us to scan up to 30% more of the breast than other scanners. Other scanners (even good ones) generally scan with a “skip”—scanning certain “slices” and skipping the ones in between. Doing this can result in missing up to 25% of the breast. And, since early breast lesions can be as small as 5mm, “skipping” even 1 mm (1 “slice”) might result in not seeing all of a patient’s lesion … or, worse, not seeing it at all.
The other day, I watched a presentation that used images from a GE system with VIBRANT; they used 3mm thick sections. At MRI Consultants, we use three times that resolution. As mentioned above, we scan with 1mm contiguous images. Because of this, we “see more" and can diagnose more cancers. At 3T, doctors are often surprised to see more extensive changes than they’d initially thought were present. This is vital—especially for Breast MRI. 3T MRI can detect lesions in your breasts that no other test can. Patients are generally advised to have a mammogram and sonogram before having a breast MRI. But when you compare what a 3T MRI can “see” with these other tests, the difference is truly astounding. Ultrasound and mammography can both miss things that are easily seen by 3T-MRI. The recent study proved this. And, MRI does this without exposing the patient to x-rays or high energy particles. Ionizing radiation is becoming increasingly problematic. Most patients are completely unaware that the risk of getting cancer is 1/500 for children per CT scan and 1/1000 in adults. A CTA (computer tomography angiographic) study uses 3 times that amount of radiation; a CT colonoscopy uses up to 4 times.
Breast MRI is just better when done at 3T. Almost every paper in the literature and all the doctors using 3T-MRI agree. Unfortunately, 3T-MRI scanners are still fairly rare—some of our patients drive all the way from Lewes. But in the future, intelligent and informed patients will demand 3T-MRI for their breast MRIs. Better images; no radiation. There is a new technique called MR spectroscopy which has been found to be useful at 3T-MRI for doing a non invasive biopsy of the breast tumor. With spectroscopy we can see if a tumor will respond to chemotherapy within 24 hours of the treatment. We also have a spceial sequence called REVEAL on our 1.5T scanner which helps to characterize breast lesions. We can do this if you want more specificity. Educated doctors insist on 3T-MRI quality. I hope you will do the same in the future.
My point? If you need a breast MRI, have it done on the very best machine available. The first time. Having an MRI done on a less powerful, inferior, machine—which can miss things—will result in your needing a second MRI on a better, more powerful, machine to confirm the results. If your test is positive on the poor test you may repeat it at 3T-MRI because you can see more. If your test is negative, you will need to repeat it to make sure there is nothing there. So, why waste your time and money? Why not be sure from the beginning? 3T-MRI is better than CT (which exposes you to radiation) and OPEN MRI (which has terrible resolution)—both of which give inconclusive results. If you need imaging, get the very best available. Be certain, use 3T-MRI. (www.3t-mri.net). For larger or claustrophobic patients we offer OPEN BORE MRI. www.bestopenmri.net OUR OPEN BORE MRI is a superconducting 1.5T scanner and is superior to all over OPEN MRI units and can be used for breast MRI. We also have a 7 channel breast coil for this unit able to do biopsies in the future. The advanced pulse sequences on our 1.5T scanner complement the speed and detail of our 3T scanner with much more room inside the scanner. We can accomodate patients up to 550 pounds on our world widest OPEN BORE 1.5T Siemens Espree.
[1] It should be noted that low field OPEN MRI cannot be used for Breast MRI because it is so low in resolution and detail.