Author: Jacinta E. Browne, Tzu Cheng Chao, Ajit Deveraj, Ece Ercan, Tim Leiner, Alessio Perazzolo, Michal Povazan, Jouke Smink, Camilla Vita, Spencer Waddle, Dinghui Wang π¨βπ¬
Affiliation: UniversitaΜ Cattolica del Sacro Cuore, Philips Healthcare, Mayo Clinic π
Purpose:
In recent years, mid-field MRI has shown promise to meet the technical demands of cardiac imaging1. Mid-field strengths offer advantages to CMR due to shorter T1-relaxation times, lower specific absorption rate and improved magnetic field homogeneity2. This study evaluates the diagnostic efficacy of high-performance 0.6T CMR imaging for quantification of ventricular morphological and functional parameters in healthy subjects.
Methods:
In this prospective study, 10 healthy subjects underwent paired CMR exams using a 1.5T scanner (Ingenia Evolution, Philips, The Netherlands) and a prototype 0.6T Philips MRI system (Philips Healthcare, Best, The Netherlands). All subjects underwent cine imaging of the heart, using breath-held balanced steadystate free precession and volumetric coverage with standard cardiac views.
The acquisition parameters used at 1.5T and 0.6T were matched apart from the flip angle which was 60Β° and 90 at 1.5T and 0.6 T. For all CINE acquisitions, ventricular morphological and functional parameters were assessed by two radiologists using contouring software (AVW, Philips, The Netherlands). Bland-Altman were used to compare paired quantitative measurements of ventricular volumes between the two CMR exams.
Two radiologists provided gradings of image quality on a 4-point scale where a score of 1 was the best image quality (IQ).
Results:
Representative comparative images are shown in Figure 1a, demonstrating the similar diagnostic quality between both scanners. Image quality metrics indicated that all short-axis cine acquisitions at both field strengths were of similar image quality and of diagnostic quality are presented in Figure 1b. Bland-Altman plots of morphological and functional parameters are shown in Figure 2, no significant difference in ejection fraction was found between scanners.
Conclusion:
This study demonstrates that a high-performance mid-field 0.6T CMR scanner is suitable and comparable to 1.5T CMR scanner in terms of cardiac volumetric analysis and diagnostic image quality and confidence.