New cardiac MRI protocol enables faster scans, possibly expanding use in clinical practice
A novel cardiac MRI technology greatly reduced the amount of time it takes for a scan, potentially lifting a barrier to use, researchers reported.
A clinical validation study of a protocol using the ultrafast technology (Enhanced Sensitivity Coding by Static Outer Volume Subtraction [ESSOS], Philips), which captures 3D images while requiring only a few breath holds from patients, was published in JACC: Cardiovascular Imaging.
Scan time a barrier
“Despite cardiac MRI (CMR) being the gold standard technique for the evaluation of the heart, it is not universally used in daily practice,” Borja Ibáñez, MD, PhD, director of the clinical research department of Centro Nacional de Investigaciones Cardiovasculares (CNIC) and cardiologist at the University Hospital Fundación Jiménez Díaz in Madrid, told Healio. “One of the main reasons for this is the long duration of scan time (usually around 45 minutes). Time of scan is a big issue for hospitals. In addition, the long duration of scan can come with discomfort for some patients, especially the most vulnerable (elderly and pediatric).”
Ibáñez and colleagues assessed left ventricular mass, volumes and ejection fraction and right ventricular EF in 107 patients (mean age, 58 years; 24% women) using a protocol involving ESSOS, 2D cine CMR and late gadolinium enhancement; each of the three parts of the protocol required a single breath hold from the patient.
“The proposed technique allows to perform a basic CMR in three breath holds providing information of cardiac anatomy, function and to allow evaluation of scar tissue in cardiac muscle,” Ibáñez told Healio. “The most novel part is the possibility to perform a cine imaging of the heart in a single breath hold without the need to set up planes. This revolutionary sequence, called ESSOS, is a co-invention between CNIC and Philips. This technique can be used in most of the magnets already available in hospitals, and thus, it could be adopted very early by hospitals. This will massively increase the accessibility of patients to the gold standard technique for the evaluation of the heart, and possibly improve patient management.”
Three-dimensional acquisitions lasted 24 seconds and late gadolinium enhancement acquisitions lasted 22 seconds, and all images were of good quality and allowed for quantification, according to the researchers.
“The ... protocol makes use of the fact that during a breath hold, everything within the patient’s chest remains static, except their beating heart,” Ibáñez told Healio. “This means that after an initial image of the static part has been captured, its MRI signal can be subtracted from subsequent scan data, allowing up to four times faster acquisition of a 3D image of the heart, resulting in a net acceleration factor up to 32. If needed, a second contrast-enhanced single breath hold scan can reveal the extent of damage to the patient’s heart muscle.”
Mean LVEF was 51% by 3D CMR and 52% by 2D CMR, and intermethod agreement was high (interclass correlation coefficient [ICC] = 0.96; 95% CI, 0.94-0.97) while bias was insignificant, according to the researchers.
Mean RVEF was 60.4% by 3D CMR and 59.7% by 2D CMR, with acceptable intermethod agreement (ICC = 0.73; 95% CI, 0.63-0.81) and insignificant bias, the researchers wrote.
The researchers are planning to publish a more technical paper to describe the methodology in more detail, and to perform global clinical studies to see if the new technology is noninferior to the standard of care for in terms of clinical decision-making, Ibáñez said in an interview.
“For patients, the proposed technique significantly increases comfort and reduces the chances for rejecting subsequent studies,” Ibáñez told Healio. “It might also allow to have patients with moderate claustrophobia scanned. These advances are especially noteworthy for vulnerable patients (ie, the elderly, patients with cancer, patients with chronic diseases, pediatric patients, etc). For providers, this technique not only will reduce the time of scan, and thus increase the number of studies performed daily in the magnet, but also reduce the need to have very experienced operators for the acquisition of a CMR, something especially relevant for non-academic hospitals.”
The technology is currently approved only for research purposes.
“It is clear that all MR scanning, including cardiac, is moving toward 3D methodologies,” Ibáñez told Healio. “Approaches like the one than we have published with new techniques are very important in this sense. In addition, these approaches open the possibility to democratize the technology, allowing more access to the population that can benefit from this imaging modality. In the past we saw a similar trend with the use of cardiac ultrasound, and now this revolution should come to the CMR field. This technique could be adopted as the standard for regular CMR exams in the near future.”
For more information:
Borja Ibáñez, MD, PhD, can be reached at Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernandez Almagro, 3, 28029 Madrid, Spain; email: email@example.com.