3DQRS: A method to obtain reliable QRS complex detection within high field MRI using 12‐lead electrocardiogram traces. Issue 4 (22nd January 2014)

• Record Type: Journal Article
• Authors: Gregory, T. Stan; Schmidt, Ehud J.; Zhang, Shelley Hualei; Ho Tse, Zion Tsz
• Is Part Of: Magnetic resonance in medicine. Volume 71:Issue 4(2014:Apr.)
• Page Start: 1374
• Page End: 1380
• Publication Date: 2014-01-22
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.25078
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm25078-sec-0001" sec-type="section"> <title>Purpose</title> <p>To develop a technique that accurately detects the QRS complex in 1.5 Tesla (T), 3T, and 7T MRI scanners.</p> </sec> <sec id="mrm25078-sec-0002" sec-type="section"> <title>Methods</title> <p>During early systole, blood is rapidly ejected into the aortic arch, traveling perpendicular to the MRI's main field, which produces a strong voltage (V<sub>MHD</sub>) that eclipses the QRS complex. Greater complexity arises in arrhythmia patients, since V<sub>MHD</sub> varies between sinus‐rhythm and arrhythmic beats. The 3DQRS method uses a kernel consisting of 6 electrocardiogram (ECG) precordial leads (V1‐V6), compiled from a 12‐lead ECG performed outside the magnet. The kernel is cross‐correlated with signals acquired inside the MRI to identify the QRS complex in real time. The 3DQRS method was evaluated against a vectorcardiogram (VCG)‐based approach in two premature ventricular contraction (PVC) and two atrial fibrillation (AF) patients, a healthy exercising athlete, and eight healthy volunteers, within 1.5T and 3T MRIs, using a prototype MRI‐conditional 12‐lead ECG system. Two volunteers were recorded at 7T using a Holter recorder.</p> </sec> <sec id="mrm25078-sec-0003" sec-type="section"> <title>Results</title> <p>For QRS complex detection, 3DQRS subject‐averaged sensitivity levels, relative to VCG were: 1.5T (100% versus 96.7%), 3T (98.9% versus 92.2%), and 7T (96.2% versus 77.7%).</p> </sec> <sec id="mrm25078-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The 3DQRS method was shown to be more effective in cardiac gating than a conventional VCG‐based method. <bold>Magn Reson Med 71:1374–1380, 2014. © 2014 Wiley Periodicals, Inc</bold>.</p> </sec> </abstract>