Bringing Abbreviated MRI Into the Clinic: Q&A

May 20, 2020
Whitney J. Palmer

Diagnostic Imaging talks with Laura Heacock, M.D., from NYU Langone Health about what’s keeping abbreviated MRI from wider implementation.

Breast MRI is already known for its greater sensitivity over mammography, and there is a growing conversation within the industry over the potential benefits of the abbreviated breast MRI – it takes less time, it acquires fewer images, it costs less, and it provides equivalent diagnostic results.

Despite these benefits, however, widespread implementation has been stymied for a variety of reasons. In a study published on May 12 in the Journal of Breast Imaging, a team led by Laura Heacock, M.D., professor of breast imaging at NYU Langone Health, outlined the benefits and challenges of using abbreviated MRI, as well as the strategies practices and imaging centers can use to more easily integrate it into the services they provide to patients.

Diagnostic Imaging spoke with Heacock about the study findings.

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Diagnostic Imaging: What are the situations where abbreviated MRI would be best suited, and what kind of benefits does it provide for the radiologist and the patient?

Heacock: It’s clear, at this point, that abbreviated breast MRI can be useful in high-risk screening. I think it’s going to open up screening for people at intermediate lifetime risk of breast cancer. So, to be specific, high lifetime risk of breast cancer, we define as greater than 20-percent lifetime risk of breast cancer, and intermediate risk, we define as between 15-percent and 20-percent lifetime risk of breast cancer.

At this point, breast MRI screening is recommended for people who are at high lifetime risk of breast cancer. These patients are usually BRCA-mutation positive or have other high-risk genetic mutations – there’s a well-defined list of reasons for why women may fall into this category. We also know that we’re not screening as many of these patients with MRI as we would like. There’s various reasons why that might be happening. Breast MRI can be expensive, and not every woman lives near a breast MRI. Not enough women may realize that they are a candidate for breast MRI screening. And, importantly, a routine breast MRI can be a long and difficult examination for a patient to tolerate.

That’s really where we think abbreviated MRI could help. If a woman knows she’s going in for a quick 10-minute examination, that’s much easier for most women to tolerate than a longer one. The MRI sequences we use in a traditional breast MRI all have a specific purpose, and women undergo breast MRIs for multiple reasons. But, in terms of screening for breast cancer, we may not need the full 30-to-40 minute exam just to find out if you have a suspicious finding. Abbreviated breast MRI for breast cancer screening can be 10 minutes or less.  And, to clarify, when I say 10 minutes, I’m talking about total exam time – with abbreviated MRI that means the time the patient is on the table.

Diagnostic Imaging: How does abbreviated MRI compared to traditional MRI for the radiologist?

Heacock: That was the purpose of this review article on abbreviated breast MRI – to summarize the different protocols that have been tested, including the plusses and the minuses of the sequences that can be added.

A normal breast MRI acquires several sequences before contrast, then additional specific images after contrast injection. These post-contrast sequences are typically acquired 1-to-3 minutes apart so that we can see how the injected gadolinium contrast washes in and out of the breast over time. In abbreviated MRI, researchers have shown that the first set of images taken after contrast are the ones most likely to show cancers. As a result, in an abbreviated MRI, we don’t acquire additional delayed post-contrast sequences. But, as the literature shows, radiologists who read these exams have the same sensitivity for breast cancer detection while shortening the exam. That means you image the patient in a shorter amount of time, and, for the radiologist, there are fewer sequences to review. That decreases radiologist interpretation time. 

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Diagnostic Imaging: What are the limitations that exist, and what impacts do they have on abbreviated MRI?

Heacock: Those are all questions we’re currently trying to sort out in the literature. Until now, most abbreviated MRI studies have been retrospective. A radiologist reviews selected abbreviated sequences from a full exam and decides if they can find a breast cancer in these images. There have been fewer prospective trials where the patient is specifically scanned with an abbreviated MRI protocol.

Recently there was a very big multi-center prospective study published which was very exciting. It’s the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) 1141 study. The initial results came out in February of this year. It was a large study in both community and academic practices in which average risk women with dense breasts were prospectively screened abbreviated breast MRI. It was compared to digital breast tomosynthesis for breast cancer detection, and the results were that abbreviated MRI had better cancer detection rates than digital breast tomosynthesis – the current standard of care for average risk screening.

So, we know that for screening, abbreviated MRI appears very useful. What is not yet known is whether it’s good for other types of breast MRI indications, as well. For example, we use breast MRI for patients with a known breast cancer to see if there are any additional concerning findings in either breast. We also use it after a woman has been diagnosed with cancer and has undergone chemotherapy to assess the treatment response. And, we also use it for problem solving when a patient has a specific concern that needs further evaluation. We need to know if these women can have an abbreviated breast MRI or a longer breast MRI.

The literature is still ongoing on whether abbreviated MRI would be as useful for evaluating the extent of disease in a known breast cancer. There have been early results, to date, that have been promising the for evaluation of known cancers. I would like to see more studies looking at this topic. We know from the evidence to date that after neoadjuvant chemotherapy, the delayed post-contrast images that we don’t use in abbreviated MRI – but use in a full-breast MRI – are useful in evaluating treatment response. These patients likely need a longer examination.

Radiologists also need to be aware that, like all breast MRI, abbreviated breast MRI has high sensitivity and accuracy for invasive cancers and high-grade ductal carcinoma in situ, but is less sensitive for low-grade DCIS. That’s not unexpected as we have already seen that with routine breast MRI.

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Diagnostic Imaging:  What about the challenges around clinical implementation. What seem to be the obstacles there?

Heacock: Clinical implementation is increasingly important. We’ve reached the stage at which the literature has been very exciting on the promise of abbreviated breast MRI, but the clinical implementation is just getting started. Especially after ECOG-ACRIN 1141 results were published, radiologists need to know how to optimize abbreviated MRI and put this into practical use.

There are a couple of different issues that need to be considered. One of the first is that there is no standardized reimbursement or CPT code for this exam yet. There have been a variety of ways outpatient centers or hospitals have sought reimbursement for abbreviated MRI. Some states have limited coverage of this through HMOs. Other places are offering this as a self-pay examination. Reimbursement remains an ongoing issue.

It’s also important to know that when we talk about 10 minutes of scan time, we’re talking about table time – the amount of time that the patient is on the table being scanned. For the patient, this starts when they hear the MRI start imaging and ends when they get off the table.

But, there’s a lot that goes on behind the scenes that the patient doesn’t see that still contributes to exam time. The technologist and other staff set up the machine, start an intravenous line, position the patient’s breasts within the breast coil, and put the patient on the table. After the examination is complete, they take out the IV, clean the room, and turn it around for the next patient. So, that 10 minutes of exam time, how does that translate into total workflow time? It’s been shown that, as you decrease the scan time, you need to also look at decreasing the turnaround time in order for this to be efficient.

For example, if your breast MRI slot at your practice is usually one hour, maybe you could perform three abbreviated MRIs in that same one-hour time period. You need to be aware that it may be more challenging than you think to set this up because you have to address technologist and workflow issues.

Diagnostic Imaging: How can practices or imaging centers get over these stumbling blocks and improve their implementation?

Heacock: By being aware. Just saying you are going to cut the exam time down by offering abbreviated breast MRI is a great first step. After that, you need to look at how you schedule breast MRIs at your practice and how you change over to the next study. Some places that have been doing this successfully have been batching the abbreviated MRIs together. So, with the example of the one-hour slot, if you’re switching to three exams instead of one, you do them all together in a row. The breast coil is there and available for use immediately for the next patient. This is more efficient than mixing-and-matching studies throughout the day – an abbreviated breast MRI followed by a different body part back to an abbreviated MRI. That’s going to be less efficient for workflow and turnaround.

You can also take a look at how your room is set up. Maybe you could increase turnaround time with duplicate breast coils with one patient being scanned while you’re positioning the next patient to be ready to go. You can switch out the gantries immediately. However, these solutions depend on how much space you have in your practice and how much duplicate equipment you would have to purchase. A radiology practice needs to identify what their potential workflow issues are to minimize turnaround time while offering abbreviated breast MRI.

We’ll see more implementation challenges arise with greater implementation of abbreviated MRI, but these are the major ones identified so far.

Diagnostic Imaging: Then, where do we go from here? What are the next steps with abbreviated MRI, and what needs to happen to move things forward?

Heacock: I think the literature at this point is excellent and has shown the promise of abbreviated breast MRI. The first big multi-center trial preliminary results have just come out, and they will be doing ongoing analysis that will be important. Part of what ECOG-ACRIN 1141 is doing is a cost-effectiveness analysis which will be very interesting. Radiologists want to know they are providing value to the patient by offering abbreviated breast MRI. To have a formal cost-effective analysis is going to be important when offering this to patients and obtaining reimbursement in the future.

There are other ongoing large prospective trials that are going to be investigating abbreviated breast MRI in different subpopulations and risk categories. For example, ECOG-ACRIN 1141 looked at women with no prior breast cancer history who had dense breasts – they were average-risk women with dense breasts. There are ongoing studies evaluating patients in different countries that have had a history of breast cancer or are high-risk BRCA mutation carriers and a history of breast cancer. These are intermediate risk patients and I think we’re going to see abbreviated MRI is a great way to screen them, as well.

Ultimately, we need to understand how cost-effective abbreviated breast MRI is and determine which patient populations benefit most. I look forward to seeing the results of these large trials and hope they will help patients have better access to this new screening tool.

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