Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2025;27(2):101925.
doi: 10.1016/j.jocmr.2025.101925. Epub 2025 Jun 19.

Comparison of pilot tone-triggered and electrocardiogram-triggered cardiac magnetic resonance imaging: a prospective clinical feasibility study

Xianling Qian  1 , Yali Wu  1 , Peter Speier  2 , Caixia Fu  3 , Yunzhu Wu  4 , Lude Cheng  5 , Yinyin Chen  1 , Shiyu Wang  1 , Caizhong Chen  1 , Kai Liu  1 , Ling Chen  1 , Hang Jin  6 , Mengsu Zeng  7
Affiliations
Comparative Study

Comparison of pilot tone-triggered and electrocardiogram-triggered cardiac magnetic resonance imaging: a prospective clinical feasibility study

Xianling Qian et al. J Cardiovasc Magn Reson. 2025.

Erratum in

Abstract

Background: Electrocardiogram (ECG)-triggered cardiovascular magnetic resonance (CMR) can be challenging in patients with ECG unreliability. Pilot tone (PT)-triggered CMR may offer a reliable alternative.

Purpose: To evaluate the feasibility of PT-triggered CMR and compare its performance with ECG-triggered imaging across various sequences in patients with common cardiovascular diseases.

Methods: This prospective study included 50 participants (26 males, 24 females; mean age 46.0±19.0y), including 15 with normal CMR findings and 35 with various cardiovascular diseases. All participants underwent both PT-triggered and ECG-triggered CMR on a 3T MRI system. Imaging included T2-weighted imaging (T2WI), T1-mapping, T2-mapping, cine, late gadolinium enhancement (LGE), and post-contrast T1-mapping sequences. Image quality and quantitative measurements were evaluated, including T2WI signal intensity, native T1-mapping, T2-mapping, and extracellular volume fraction (ECV) values, and comparative signal-to-noise ratio (compSNR) and comparative contrast-to-noise ratio (compCNR) of cine and LGE images, left/right ventricular function. Inter-reader agreement was evaluated using the intraclass correlation coefficient (ICC). Comparisons between the two methods were performed using paired t-test or the Wilcoxon signed-rank test.

Results: No significant differences were observed in scanning times (p=.253-.864) or image quality (ICC: .589-1.000, p=.057-1.000) between PT- and ECG-triggered scans and images. Quantitative assessments showed good to excellent consistency (ICC=.843-.987). While PT-triggered LGE images showed higher compCNR (14.14±7.68 vs. 13.24±7.52, p=.016), other quantitative parameters showed no significant differences between PT- and ECG-triggered images. Six participants with hypertrophic cardiomyopathy or heart valve disease experienced false R-wave triggering during ECG gating, leading to motion artifacts, which were not visible in PT-triggered images.

Conclusion: PT-triggered cardiac MRI provides comparable image quality and quantitative assessments to ECG-triggered sequences and may offer advantages in minimizing motion artifacts, particularly in patients with conditions affecting ECG reliability, making it a promising alternative for cardiac MRI synchronization.

Keywords: Cardiac magnetic resonance; Electrocardiogram; Pilot tone.

PubMed Disclaimer

Conflict of interest statement

Declaration of competing interests All authors confirm that this paper is solely under submission to Journal of Cardiovascular Magnetic Resonance and has not been previously published, in part or whole. No subject overlaps with previously published works. Regarding conflicts of interest, authors P.S., C.X.F., Y.Z.W., and L.D.C. are employees of Siemens healthineers, the manufacturers of the 3.0T MRI equipment used in this study, and have provided advice on sequence parameter adjustments. The remaining authors, not affiliated with Siemens healthineers, controlled and analyzed over all data analysis to mitigate potential conflicts of interest. No other conflicts of interest are declared by the authors.

Figures

ga1
Graphical abstract
Fig. 1
Fig. 1
Flowchart of the prospective comparative study. ECG electrocardiogram, T2WI T2-weighted imaging, LGE late gadolinium enhancement, ECV extracellular volume, PT pilot tone
Fig. 2
Fig. 2
Bland-Altman plots demonstrate the agreement between quantitative parameters derived from PT-triggered and ECG-triggered images. These parameters include the ratio of T2WI signal intensity of myocardium to skeletal muscle (SImyo/SISM), native T1-mapping value, T2-mapping value, compSNR and compCNR for cine and LGE images, as well as ECV. PT Pilot Tone, ECG electrocardiogram, T2WI T2-weighted imaging, compSNR comparative signal-to-noise ratio, compCNR comparative contrast-to-noise ratio, LGE late gadolinium enhancement, ECV extracellular volume
Fig. 3
Fig. 3
AHA 16-segment models of the ratio of T2WI signal intensity of myocardium to skeletal muscle (SImyo/SISM), native T1-mapping value (ms), T2-mapping value (ms), and ECV (%) based on Pilot Tone-triggered and ECG-triggered images. ECV extracellular volume, ECG electrocardiogram
Fig. 4
Fig. 4
Raincloud plots illustrate the agreement in left and right ventricular function parameters, including EDV (mL), ESV (mL), SV (mL), EF (%), and CO (L/min), as well as LGE mass (g), between PT-triggered and ECG-triggered images. EDV end-diastolic volume, ESV end-systolic volume, SV stroke volume, EF ejection fraction, CO cardiac output, LGE late gadolinium enhancement, PT Pilot Tone, ECG electrocardiogram
Fig. 5
Fig. 5
Examples comparing CMR images triggered by PT and ECG, with and without ECG distortion. (A-P) PT- and ECG-triggered images with accurate R-wave triggering from a 67-year-old male participant with HCM. The image quality of conventional sequences triggered by PT was comparable to that of ECG-triggered images with accurate R-wave detection. Both PT- and ECG-triggered LGE images, as well as post-processed ECV images, exhibited similar high quality, clearly visualizing the extent of myocardial fibrosis (white arrow). (Q-Z) PT- and ECG-triggered images with false R-wave triggering from a 70-year-old female participant with HCM. While both PT- and ECG-triggered T1-mapping and LGE images showed good image quality and clearly depicted myocardial fibrosis (white arrow), ECG-triggered T2WI (V) and cine (Y) images exhibited motion artifacts and signal loss due to R-wave misgating (red circles), which were absent in PT-triggered images (Q and T). PT Pilot Tone, ECG electrocardiogram, HCM hypertrophic cardiomyopathy, LGE late gadolinium enhancement, ECV extracellular volume, T2WI T2-weighted imaging
See this image and copyright information in PMC

References

    1. Scott A.D., Keegan J., Firmin D.N. Motion in cardiovascular MR imaging. Radiology. 2009;250(2):331–351. doi: 10.1148/radiol.2502071998. - DOI - PubMed
    1. Frauenrath T., Hezel F., Heinrichs U., Kozerke S., Utting J.F., Kob M., et al. Feasibility of cardiac gating free of interference with electro-magnetic fields at 1.5 Tesla, 3.0 Tesla and 7.0 Tesla using an MR-stethoscope. Invest Radio. 2009;44(9):539–547. doi: 10.1097/RLI.0b013e3181b4c15e. - DOI - PubMed
    1. Lanzer P., Barta C., Botvinick E.H., Wiesendanger H.U., Modin G., Higgins C.B. ECG-synchronized cardiac MR imaging: method and evaluation. Radiology. 1985;155(3):681–686. doi: 10.1148/radiology.155.3.4001369. - DOI - PubMed
    1. Krug J.W., Rose G., Clifford G.D., Oster J. ECG-based gating in ultra high field cardiovascular magnetic resonance using an independent component analysis approach. J Cardiovasc Magn Reson. 2013;15(1) doi: 10.1186/1532-429x-15-104. - DOI - PMC - PubMed
    1. Snyder C.J., DelaBarre L., Metzger G.J., van de Moortele P.F., Akgun C., Ugurbil K., et al. Initial results of cardiac imaging at 7 Tesla. Magn Reson Med. 2009;61(3):517–524. doi: 10.1002/mrm.21895. - DOI - PMC - PubMed

Publication types