Magnetic Resonance Imaging Versus Computed Tomography Angiography for Transcatheter Aortic Valve Replacement Planning: A Single-Center Experience

In this interview with JIC, Dr Alison N. Ranum of the Hospital of the University of Pennsylvania shares insights on her study, "Magnetic Resonance Imaging Versus Computed Tomography Angiography for Transcatheter Aortic Valve Replacement Planning: A Single-Center Experience," presented at the 2026 American College of Cardiology (ACC) Conference.

Read the full interview below.

Click here for the video transcript.

Your study shows that cMRI was used in only 2% of TAVR cases—what institutional or clinical factors do you think are limiting broader adoption of cMRI for TAVR planning, or is it simply based on habit?

I think the limited use of cMRI in TAVR planning reflects a combination of both institutional and clinical factors. From an institutional standpoint, access is a major barrier with cMRI requiring specialized equipment, longer scan times, and dedicated expertise, which not all centers have readily available.

Clinically, what I think ends up happening is that oftentimes it's easier for us to rely on the gold standard CTA and to feel more comfortable interpreting those measurements due to improved spatial resolution.

The cMRI group had significantly higher rates of kidney disease, diabetes, and PAD. To what extent do you think this reflects intentional patient selection versus underlying referral bias at your center, and how did (or did) this affect your analysis of the results?

I think this pattern is largely driven by intentional patient selection rather than referral bias. In particular, patients with advanced kidney disease, which we often see in the setting of diabetes, are more likely to be steered toward cMRI to avoid iodinated contrast exposure from CTA. So in that sense, the higher prevalence of renal disease, diabetes, and PAD in the cMRI group reflects a clinically driven decision-making process. That said, I don’t think referral bias can be completely excluded, since institutional practices and provider preferences may also influence which patients are sent for cMRI versus CTA. 

How confident can clinicians be in cMRI-based annular sizing compared with CTA, especially given the small sample size?

That’s an important question, especially given that CTA is still considered the reference standard for annular sizing due to its high spatial resolution and extensive validation. While our study is limited by a small sample size, the findings are reassuring. We did not observe meaningful differences in key procedural outcomes between the cMRI and CTA groups, which suggests that cMRI-based sizing was clinically adequate in this cohort. In addition, in the subset of patients who underwent both imaging modalities, the annular measurements were comparable, further supporting the reliability of cMRI. That said, I would frame cMRI as a promising alternative for particular patients, rather than a global replacement for CTA at this point.  

One notable procedural difference was the higher rate of pre-deployment balloon valvuloplasty in the cMRI group—what might explain this finding, and could it signal any subtle limitations of cMRI in procedural planning?

That’s a really interesting finding. One possible explanation is the difference in spatial resolution between cMRI and CTA, which may introduce slightly more uncertainty in annular sizing or valve positioning. As a result, operators may be more inclined to perform pre-deployment balloon valvuloplasty as a way to better assess valve expansion and optimize procedural outcomes.In terms of whether this signals a limitation, I think it’s a subtle one. While it may suggest slightly less confidence in pre-procedural sizing, the fact that there were no significant differences in adverse or procedural outcomes between the groups is reassuring. So overall, it may indicate an adjustment in technique rather than a clinically meaningful drawback of cMRI.

How do you envision cMRI fitting into future TAVR workflows, particularly for patients with advanced kidney disease or other high-risk comorbidities?

I see cMRI becoming an important complementary tool in TAVR workflows, especially for patients with advanced kidney disease or other comorbidities where contrast exposure is a concern. This study adds to prior evidence that cMRI can provide reliable annular sizing and procedural planning while avoiding the risks associated with iodinated contrast.

In practice, I envision cMRI being used selectively for high-risk patients. Over time, as experience grows and protocols become standardized, it could become a routine option for patients who would benefit from a contrast-free approach, allowing us to tailor planning to each patient’s comorbidities without compromising outcomes.

Beyond eliminating contrast use, are there any clear advantages of cMRI over CTA that would justify choosing cMRI for patients without contraindications such as kidney disease?

Eliminating the use of contrast is the biggest advantage to cMRI use for TAVR planning.