Water-fat separation sequence yields superior image quality compared to standard coronary MRA
A study published recently in the American Journal of Roentgenology found that a 3-T Dixon water-fat separation gradient-recalled echo (GRE) performed better than standard MR methods on unenhanced magnetic resonance angiography (MRA).
Compared to 1.5-T SSFP examinations, which are commonly used for MRA, the 3-T Dixon GRE coronary MRA method produced better image quality and yielded better overall diagnostic performance, according to experts involved in the study.
“Coronary MRA at 3 T is limited using SSFP due to impaired fat suppression and has been investigated typically using contrast-enhanced techniques,” lead researcher Hang Jin, from China’s Fudan University and Shanghai Institute of Medical Imaging, and co-authors discussed. “Dixon methods, based on the chemical shift phenomenon, provide exquisite separation of water and fat signal, and have become increasingly available using modern MRI systems.”
Researchers hypothesized that using Dixon methods for coronary MRAs might improve image quality and give radiologists a more detailed view of coronary artery disease. They tested their theory on 44 patients with intermediate to high CAD risk, who underwent both 1.5-T SSFP and 3-T Dixon GRE coronary MRA examinations before coronary angiography (CA). When assessing the coronary arteries, two radiologists rated subjective image quality, number of visible segments, apparent contrast-to-noise ratio and presence of significant stenoses on a scale of 1-5 (5 representing the highest quality).
The experts observed higher image quality and better visualization of coronary segments using the 3-T unenhanced Dixon GRE method. Higher sensitivity (87.9% vs 77.3%) and specificity (83.3% vs 60.6%) for significant stenoses on a per-vessel basis, especially for distal and branch segments, was also demonstrated with that same sequence.
“The findings indicate a role for the 3-T Dixon GRE method to facilitate improved image quality and diagnostic performance of whole-heart coronary MRA compared with current clinically standard 1.5-T methods without the need for exogenous contrast agents,” the experts explained. “This improvement in performance without contrast material administration could encourage wider clinical adoption of coronary MRA in clinical practice.”
The researchers noted that the 3-T Dixon GRE method could also reduce the number of false-positive CAD diagnoses that 1.5-T SSFP sequences produce, thus improving patient care and clinical outcomes.
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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She joined Innovate Healthcare in 2021 and has since put her unique expertise to use in her editorial role with Health Imaging.