The value of magnetic resonance imaging (MRI) is an indisputable diagnostic tool, yet the time-consuming nature of these scans creates challenges for acquiring high-resolution images and limits overall accessibility of the technology. Following the success of AIR Recon DL, GE HealthCare developed Sonic DL[i], which enables new imaging paradigms such as high-quality cardiac MRI in a single heartbeat – improving scheduling – and expanding access to a larger patient pool who may have had difficulties with traditional cardiac MR scanning.
Challenges in cardiac imaging using MR technology
MR delivers high-resolution visualization of the structure of the heart, including its walls, chambers and valves, and enables implicit measurement of blood flow through the heart. This provides information sufficient to diagnose conditions like heart disease, cancer, valve defects and heart failure, as well as many other cardiac health issues. MR is considered the gold standard for diagnostic cardiac imaging, but acquisition can require lengthy amounts of time and frequent breath-holding, which is stressful on some patients and outright exclusionary for others.
Long image scans versus motion
Acquisition of a detailed MR scan takes time, and if a patient moves while the image is being acquired, it blurs, reducing the diagnostic quality. Cardiac imaging is particularly complicated by two factors: movement of the chest wall during respiration, and movement of the heart itself. Movement of the chest wall is controllable for some patients by asking them to hold their breath, but others who are very sick and already experiencing cardiovascular problems may be unable to do this, rendering MR scan-based diagnostics inaccessible to them. Moreover, even in patients who are capable of breath-holding, the beat of a heart is involuntary, and this vital organ is constantly in motion – and you cannot very well ask a patient to stop their heart from beating.
To compensate for the continuous motion of the heart, images must be acquired multiple times to try and catch the heart at each point of movement, and then these images must be stitched together to infer the appearance of the structures in motion. And with each set of image acquisitions, patients must hold their breath to reduce background.
Increasing MR accessibility to new patient pools
The total volume of acquisitions and the frequent breath-holding can be especially stressful for patients who are already experiencing cardiovascular stress or arrhythmias. GE HealthCare aims to solve this problem by advancing the rapidity with which high-resolution MR images can be obtained using Sonic DL.
Sonic DL is a deep-learning reconstruction method used to provide highly accelerated functional imaging of the heart. This novel technology has a temporal resolution as low as 10 ms, which allows for the unprecedented ability to perform scans within a single heartbeat. These rapid scans have sufficient resolution to enable measurement of blood volume and substantially reduce the amount of time it takes to obtain the images needed for diagnostic evaluation.
The rapid scans from this technology also support acquisition of sufficiently detailed MR images while the patient is free-breathing, which was previously impossible. With the help of Sonic DL, patients who are unable to hold their breath for MR scans now have potential accessibility to this invaluable diagnostic method.
Reducing patient stress
MR scanning is notoriously difficult on pediatric, elderly, claustrophobic, or very sick patients because of the extensive amount of time holding still in a tightly enclosed space. The amount of time it takes to acquire all of the necessary images amounts to a substantial amount of time during which patients are in the MR machine, which can be particularly stressful. They may quickly become restless or uncooperative, or simply find themselves unable to maintain the stillness necessary to obtain a high-resolution image.
Sonic DL provides up to 12-fold acceleration of cardiac MR image acquisition, resulting in up to 4-fold reduction in scan time to assess cardiac function and volume. Hence, patients are required to spend substantially less time inside the MR scanners, reducing their discomfort and the challenges the technicians face caring for patients who find it difficult to remain still or ask to end their scan early. Faster image acquisition also reduces the chance of movement while the patient is being scanned, which reduces likelihood of having to repeat the imaging.
Increasing MR accessibility to more patients overall
These boosts in efficiency enable more rapid patient throughput — more patients can be scanned within a given timeframe, and with less need for re-scanning, more patients can gain initial access to the MR machine. Ultimately, more rapid MR scans reduce patient backlogs and can potentially improve departmental efficiency, reducing the need for overtime hours, and prevent technician burnout. Faster imaging can also mean quicker time to diagnosis and treatment for most patients, which improves their quality of care.
Sonic DL’s ability to assist in obtaining high-resolution diagnostic MR scans within a single heartbeat even in free-breathing patients is unprecedented. These enhancements to MR scanning technology have the potential to expand accessibility to patients, not just in terms of the number of patients that can have images acquired in a given day, but also the types of patients – e.g., pediatric, restless, claustrophobic, patients or patients with arrythmias or unable to breath-hold. Moreover, the enhanced efficiency of MR scanning that results from reduced time to image acquisition and reduced need for repeat imaging results in better patient throughput that can aid patients and radiology departments alike.
The future of MRI
GE HealthCare's commitment to advancing MRI through cutting-edge AI deep learning technology has been exemplified by AIR Recon DL, and now Sonic DL is revolutionizing the speed of imaging one anatomy at a time. The future of MRI holds great promise, as advancements like Sonic DL continue to push the boundaries of what is possible, ultimately benefiting patients, healthcare providers, and the field of diagnostic imaging as a whole.
[i] Sonic DL is not yet CE marked. Not commercially available in all markets.