An International Multicenter, Multivendor Evaluation of the Free-Running Framework for Cardiac Function

Cardiovascular disease remains the leading cause of death in industrialized nations. While a range of diagnostic tools exists for cardiovascular disease detection and monitoring, magnetic resonance imaging (MRI) remains the only modality that enables a safe, non-invasive assessment of the heart without exposure to ionizing radiation. MRI allows for a comprehensive evaluation of cardiac anatomy, function, myocardial tissue characterization, and blood flow quantification, making it a powerful tool for cardiovascular diagnostics.

Despite strong clinical evidence supporting its utility, cardiac MRI (CMR) remains underutilized, primarily due to the length and complexity of a traditional CMR exam. Several factors contribute to the length and complexity of a standard CMR exam. First, a standard CMR protocol relies heavily on two-dimensional (2D) image acquisitions, each requiring manual slice planning by an experienced technologist-a process that is both time consuming and highly dependent on operator expertise. Second, traditional image acquisition requires electrocardiogram (ECG) triggering to synchronize with the cardiac cycle, requiring additional setup and potentially introducing errors if the ECG signal is suboptimal. Finally, most conventional sequences rely on repeated patient breath-holding to minimize respiratory motion artifacts, which can be particularly challenging for individuals with severe cardiovascular disease, congenital anomalies, or limited compliance. Even for highly skilled personnel, this process is timeconsuming and inefficient. Consequently, a significant portion of the patient's time in the scanner is spent on preparation and planning rather than actual image acquisition, leading to prolonged exam durations and increased healthcare costs.

Given these challenges, there is a strong need for simplified, automated, and time-efficient CMR acquisitions. In response to this challenge, the investigators research group has developed an innovative "free-running framework" (FRF)-a set of MRI methods that continuously acquire threedimensional (3D) image data across the entire cardiac cycle and throughout free breathing, irrespective of cardiac or respiratory motion. Unlike conventional CMR sequences that require separate, prospectively planned acquisitions for each imaging plane and time point, FRF employs continuous, self-navigated data acquisition. This eliminates the need for complex slice planning and enables retrospective reconstruction of cardiac motion, ensuring that imaging is both standardized and independent of user expertise. By leveraging advanced motion-resolved reconstruction algorithms developed by the investigators group, the investigators can derive both cardiac and respiratory motion from a single dataset, providing a fully automated, 3D whole-heart imaging approach.

Once diagnosed, patients with cardiac diseases often require lifelong monitoring and repeated imaging assessments to guide treatment decisions and evaluate disease progression. This makes a non-ionizing imaging modality like CMR admirable. Nonetheless, the prolonged scan durations and intricate manual planning associated with traditional CMR limit its accessibility and practical feasibility. By eliminating the need for slice planning and reducing scan complexity, FRF has the potential to significantly improve imaging for cardiac disease patients by:

• Standardizing imaging: producing user-independent results robust to anatomical variations.
• Reducing scan times: without compromising diagnostic information.
• Improving accessibility: enabling easier adoption in centers with less experienced technologists.

The feasibility of FRF has been demonstrated in experimental, pre-clinical, and small observational clinical studies, with no observed adverse effects. This study aims to evaluate its clinical feasibility and efficiency in real-world cardiac disease patients across multiple cardiac institutions, serving as a precursor for larger validation studies and eventual clinical implementation. This study will provide the first systematic clinical evaluation of 3D FRF across multiple cardiac institutions in cardiac disease patients, assessing both its technical feasibility and potential workflow benefits in a real-world setting. In particular, this study will:

• Evaluate whether diagnostic information from FRF matches or exceeds standard CMR.
• Assess the efficiency gains and the impact of automated, self-navigated imaging on scan duration and patient comfort.

If successful, this study will lay the groundwork for future multi-center validation clinical trial studies and eventual clinical integration, addressing a critical gap in CMR accessibility and efficiency.

Inclusion criteria

• Diagnosed with cardiac disease of any complexity and scheduled for a clinical cardiac MRI on a clinical 1.5T MRI scanner
• Able to understand and provide written informed consent or, for minors, ability to provide assent with written consent from a parent/legal representative, per local law and site policy prior to the study
• Ability to undergo MRI without contraindications
• Agrees to be informed in the event of incidental findings

Exclusion criteria

• Severe claustrophobia preventing MRI completion
• Presence of non-MRI compatible implants (e.g., pacemakers, certain metallic implants)
• Contraindications to the intravenous contrast agent
• Movement disorders or inability to remain still during the scan