Will abdominal aortic atherosclerosis be visible on a Magnetic Resonance Imaging (MRI) of the lumbar spine without contrast?

Visibility of Abdominal Aortic Atherosclerosis on Non-Contrast MRI Lumbar Spine

Yes, abdominal aortic atherosclerosis can be detected on non-contrast MRI of the lumbar spine, though with limitations compared to dedicated vascular imaging studies. 1

Detection Capabilities of Non-Contrast MRI

• Non-contrast MRI using double-inversion recovery T1-weighted imaging and balanced steady-state free-precession sequences can visualize the aorta, especially when ECG-gated 1
• MRI without contrast can evaluate the composition of atherosclerotic plaques, including lipids, fibrosis, calcifications, and intraplaque hemorrhage 1
• The accuracy of balanced steady-state free-precession MRA approaches 100% for detecting major aortic pathologies, though this refers to dedicated aortic imaging rather than incidental findings on lumbar spine MRI 1
• Non-contrast MRI may underestimate the thickness of atherosclerotic plaques compared to other modalities 1

Limitations of Incidental Detection

• Standard lumbar spine MRI protocols are not optimized for vascular assessment and may miss smaller atherosclerotic lesions 1
• Without contrast, visualization of the aortic lumen and wall is less detailed, potentially missing non-calcified plaques 1
• Incidentally detected atherosclerotic lesions on imaging studies are associated with higher risk for coronary artery disease, making their identification clinically relevant 2

Technical Considerations

• T2-weighted imaging can help identify thrombus (high signal) and lipid core (low signal) within atherosclerotic lesions 3
• The fibrous cap of atherosclerotic plaques may be visualized as areas of uniform increased signal on T2-weighted imaging 3
• MRI reproducibility studies have shown high correlation for measurements of total aortic lumen area and circumference (r=0.98, p<0.001), though slice-specific plaque measurements are less robust (r=0.62-0.85) 4

Comparison with Other Modalities

• CT without contrast is more sensitive (83%-89%) than ultrasound (57%-70%) for identifying abdominal aortic aneurysms, with high specificity (>98%) 1
• For comprehensive aortic assessment, CTA with IV contrast remains the gold standard, providing information about the aortic lumen, wall, and surrounding structures 1, 5
• Ultrasound is the recommended first-line screening tool for abdominal aortic aneurysms but may not adequately characterize atherosclerotic disease 1, 5

Clinical Implications

• When atherosclerotic changes are incidentally noted on lumbar spine MRI, consider the potential association with coronary heart disease 2
• If significant atherosclerotic disease is detected incidentally, further dedicated vascular imaging may be warranted for proper assessment 1, 5
• The detection of calcified atherosclerotic plaque on non-contrast imaging should prompt consideration of cardiovascular risk assessment 1, 2

Pitfalls and Caveats

• Non-contrast lumbar spine MRI may miss non-calcified atherosclerotic plaques that would be visible with contrast enhancement 1
• Standard spine imaging protocols may not include optimal sequences for vascular assessment 1
• Incidental findings should be interpreted with caution, as the study was not optimized for vascular evaluation 1
• Patient motion and pulsation artifacts can further limit the ability to detect subtle vascular pathology on non-dedicated imaging 1