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[Stress cine MRI for detection of coronary artery disease]
Insights
Stress MRI offers a superior, non-invasive method for diagnosing coronary artery disease (CAD) compared to stress echocardiography. Its advanced imaging provides clearer results, especially for patients with poor echocardiogram quality.
Area of Science:
- Cardiology
- Medical Imaging
- Diagnostic Techniques
Context:
- Stress testing is crucial for diagnosing coronary artery disease (CAD).
- Stress echocardiography is a common but user-dependent diagnostic tool with limitations in image quality and reproducibility.
- Magnetic Resonance Imaging (MRI) offers high spatial and contrast resolution for cardiac assessment.
Purpose:
- To evaluate the efficacy of stress MRI, particularly dobutamine-atropine stress MRI, in detecting CAD.
- To compare the diagnostic performance of stress MRI against stress echocardiography.
- To highlight the advantages of stress MRI in overcoming the limitations of stress echocardiography.
Summary:
- Ultrafast MRI acquisition has improved stress MRI's clinical utility by reducing scan times and enhancing patient safety.
- High-dose dobutamine/atropine stress MRI protocols demonstrate good sensitivity (83-87%) and specificity (83-86%) for CAD detection.
- Direct comparisons show dobutamine-stress MRI outperforms dobutamine stress echocardiography in sensitivity and specificity due to superior image quality.
Impact:
- Stress MRI is emerging as a viable clinical alternative for non-invasive CAD assessment, especially in patients with suboptimal echocardiographic images.
- The enhanced image quality of MRI allows for precise delineation of cardiac borders, leading to more accurate diagnoses.
- Advancements in stress MRI technology are improving patient safety and diagnostic accuracy in cardiology.
Abstract:
Stress testing is the cornerstone in the diagnosis of patients with suspected coronary artery disease (CAD). Stress echocardiography has become a well-established modality for the detection of ischemia-induced wall motion abnormalities. However, display and reliable interpretation of stress echocardiography studies are user-dependent, the test reproducibility is low, and 10 to 15 % of patients yield suboptimal or non-diagnostic images. Due to its high spatial and contrast resolution, MRI is known to permit an accurate determination of left ventricular function and wall thickness at rest. Early stress MRI studies provided promising results with respect to the detection of CAD. However, the clinical impact was limited due to long imaging time and problematic patient monitoring in the MRI environment. Recent technical improvements - namely ultrafast MR image acquisition - led to a significant reduction of imaging time and improved patient safety. Stress can be induced by physical exercise or pharmacologically by administration of a beta1-agonist (dobutamine) or vasodilatator (dipyridamole and adenosine). The best developed and most promising stress MRI technique is a high-dose dobutamine/atropine stress protocol (10, 20, 30, 40 microgram/kg/min; optionally 0.25-mg fractions of atropine up to maximal dose 1 mg). Severe complications (myocardial infarction, ventricular fibrillation and sustained tachycardia, cardiogenic shock) may be expected in 0.25 % of patients. Currently, data of three high-dose dobutamine stress MRI studies are available, revealing a good sensitivity (83 - 87 %) and specificity (83 - 86 %) in the assessment of CAD. The direct comparison between echocardiography and MRI for the detection of stress-induced wall motion abnormalities yielded better results for dobutamine-MRI in terms of sensitivity (86.2 % vs. 74.3 %; p < 0.05) and specificity (85.7 % vs. 69.8 % p < 0.05) as compared to dobutamine stress echocardiography. The superior results of MRI can mainly be explained by the better image quality with sharp delineation of the endocardial and epicardial borders. Currently, stress MRI is already a realistic clinical alternative for the non-invasive assessment of CAD in patients with impaired image quality in echocardiography.