Retrospective adaptive motion correction for navigator-gated 3D coronary MR angiography

Wang, Yi; Ehman, Richard L.

doi:10.1002/(sici)1522-2586(200002)11:2<208::aid-jmri20>3.0.co;2-9

Cited by 54 publications

(43 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No statistical difference (P = .06) was found between the body mass index of subjects with CAD risk factors (mean, 25 6 5; range, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] and healthy subjects (mean, 22 6 4; range, [20][21][22][23][24][25][26][27][28][29][30]. Subjects with CAD risk factors were significantly older than healthy subjects (P , .001), while there was no significant difference in age between men and women with CAD risk factors (P = .7).…”

Section: Resultsmentioning

confidence: 99%

“…Thus, the cumulative effect of multiple cine phases was assessed in comparison with single (first cine phase) vessel wall imaging that is equivalent to the typical dual and correction (29). The navigator was localized at the lung-liver interface of the right hemidiaphragm with a 3-mm gating window and a correction factor of 0.6 in the superior-inferior direction (30). Immediately after dual inversion, a navigator-restore pulse (31) was used to optimize navigator performance.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Coronary Vessel Wall 3-T MR Imaging with Time-resolved Acquisition of Phase-Sensitive Dual Inversion-Recovery (TRAPD) Technique: Initial Results in Patients with Risk Factors for Coronary Artery Disease

Abd‐Elmoniem

Gharib²,

Pettigrew³

2012

Radiology

View full text Add to dashboard Cite

Purpose:To develop a technique for time-resolved acquisition of phasesensitive dual-inversion recovery (TRAPD) coronary vessel wall magnetic resonance (MR) images, to investigate the success rate in coronary wall imaging compared with that of single-frame imaging, and to assess vessel wall thickness in healthy subjects and subjects with risk factors for coronary artery disease (CAD). Materials andMethods:Thirty-eight subjects (12 healthy subjects, 26 subjects with at least one CAD risk factor) provided informed consent for participation in this institutional review board-approved and HIPAA-compliant study. The TRAPD coronary vessel wall imaging sequence was developed and validated with a flow phantom. Time-resolved coronary artery wall images at three to five cine phases were obtained in all subjects. Qualitative and quantitative comparisons were made between TRAPD and conventional single-image wall measurements. Measurement reproducibility also was assessed. Statistical analysis was performed for all comparisons. Results:The TRAPD sequence successfully restored the negative polarity of lumen signal and enhanced lumen wall contrast on the cine images of the flow phantom and in all subjects. Use of three to five frames increased the success rate of acquiring at least one image of good to excellent quality from 76% in single-image acquisitions to 95% with the TRAPD sequence. The difference in vessel wall thickness between healthy subjects and subjects with CAD risk factors was significant (P , .05) with the TRAPD sequence (1.07 vs 1.46 mm, respectively; 36% increase) compared with single-frame dual inversion-recovery imaging (1.24 vs 1.55 mm, respectively; 25% increase). Intraobserver, interobserver, and interexamination agreement for wall thickness measurement were 0.98, 0.97, and 0.92, respectively. Conclusion:TRAPD imaging of coronary arteries improved arterial wall visualization and quantitative assessment by increasing the success rate of obtaining good-to excellent-quality images and sections orthogonal to the longitudinal axis of the vessel. This also resulted in vessel wall thickness measurements that show a more distinct difference between healthy subjects and those with CAD risk factors.q RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup /suppl

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Coronary Vessel Wall 3-T MR Imaging with Time-resolved Acquisition of Phase-Sensitive Dual Inversion-Recovery (TRAPD) Technique: Initial Results in Patients with Risk Factors for Coronary Artery Disease

Abd‐Elmoniem

Gharib²,

Pettigrew³

2012

Radiology

View full text Add to dashboard Cite

show abstract

“…The main reason for this, of course, is that the motion of the heart with respiration is complex, and in addition to a simple linear translation it also undergoes twisting and rotation (16,17), with differences observed between inspiratory and expiratory phases (18). In addi- tion to a possible breakdown of the linear model, using slice-following over a wide range of diaphragmatic motion results in ghosting from structures within the image field of view that do not move with the structures being followed.…”

Section: Discussionmentioning

confidence: 99%

Coronary artery motion with the respiratory cycle during breath‐holding and free‐breathing: Implications for slice‐followed coronary artery imaging

Keegan¹,

Gatehouse²,

Yang

et al. 2002

Magnetic Resonance in Med

View full text Add to dashboard Cite

The displacement of the right coronary artery (RCA) origin with respiratory position was determined relative to the dome of the right hemidiaphragm in three orthogonal directions in eight healthy subjects. Both multiple breath-hold and free-breathing acquisitions were used, and motion correction factors for slicefollowing applications were determined. The correction factors for all three directions showed considerable intersubject variability. The mean superior-inferior factor was slightly less in free-breathing than in breath-holding (0.26 vs. 0.29, P ‫؍‬ ns), and much less than the fixed value of 0.6 frequently implemented with slice-following. The anterior-posterior correction factors were uniformly low in free-breathing, and significantly less than those obtained from breath-holding (0.04 vs. 0.14, P < .05), while the mean left-right correction factors were approximately 0.1 for both. It is concluded that subject variability in correction factors, together with within-subject differences between breath-holding and free-breathing, is such that slice-following should be performed with subject-specific factors determined from free-breathing acquisitions. Key words: respiratory motion; slice-following; coronary artery; breath-holding; free-breathing Navigator-echo controlled free-breathing coronary artery studies (1) typically use a navigator positioned through the dome of the right hemidiaphragm, and an acceptance window of 5 mm to give a reasonable compromise between scan efficiency and image quality. However, during prolonged studies drifting of the respiratory pattern leads to a corresponding fall in efficiency (2), resulting in registration errors between scans and a frequent need to reposition the acceptance window. Real-time slice-following (3) has the potential to increase the scan efficiency and reduce the sensitivity to respiratory drift by allowing the implementation of a larger navigator acceptance window.The efficacy of real-time slice-following is critically dependent on the accuracy with which the motion of the heart can be predicted from the navigator echo data. In 1995, Wang and colleagues (4) used multiple 2D breathhold acquisitions to show a linear relationship between the superior-inferior (SI) motion of the heart and that of the diaphragm in healthy volunteers. In this subject group, the mean correction factor relating the SI motion of the right coronary artery (RCA) origin to that of the diaphragm was 0.57 (Ϯ0.26), and the anterior-posterior (AP) motion was approximately 20% of that in the SI direction (or 12% of that of the diaphragm). Some implementations of slicefollowing consequently use a fixed SI correction factor of 0.6, with or without a fixed AP factor of 0.12 (5,6). This approach has been shown to improve the quality of images acquired with 5-mm and 7-mm navigator acceptance windows, but has failed to produce good quality images when the acceptance window is increased to cover the entire range of respiratory positions (3). This may be due to a failure of the linear model, or to in...

show abstract

“…Alongside respiratory gating using bellows 21 , respiratory navigator gating 9, 22–25 was developed, which proved more suited for coronary imaging 26 . Coronary MRA keeps driving the development of more advanced respiratory navigator techniques such as retrospective adaptive motion correction 27, 28 and self-navigation 29, 30 . Respiratory navigator gating is generally used for 4D flow MRI as well, as the relatively long scan times make breath-hold acquisitions impractical if not impossible.…”

Section: Discussionmentioning

confidence: 99%

Improved respiratory navigator gating for thoracic 4D flow MRI

Ooij

Semaan

Schnell

et al. 2015

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Background Thoracic and abdominal 4D flow MRI is typically acquired in combination with navigator respiration control which can result in highly variable scan efficiency (Seff) and thus total scan time due to inter-individual variability in breathing patterns. The aim of this study was to test the feasibility of an improved respiratory control strategy based on diaphragm navigator gating with fixed Seff, respiratory driven phase encoding, and a navigator training phase. Methods 4D flow MRI of the thoracic aorta was performed in 10 healthy subjects at 1.5T and 3T systems for the in-vivo assessment of aortic time-resolved 3D blood flow velocities. For each subject, four 4D flow scans (1: conventional navigator gating, 2–4: new implementation with fixed Seff =60%, 80% and 100%) were acquired. Data analysis included semi-quantitative evaluation of image quality of the 4D flow magnitude images (image quality grading on a four point scale), 3D segmentation of the thoracic aorta, and voxel-by-voxel comparisons of systolic 3D flow velocity vector fields between scans. Results Conventional navigator gating resulted in variable Seff = 74±13% (range = 56% – 100%) due to inter-individual variability of respiration patterns. For scans 2–4, the the new navigator implementation was able to achieve predictable total scan times with stable Seff, only depending on heart rate. Semi- and fully quantitative analysis of image quality in 4D flow magnitude images was similar for the new navigator scheme compared to conventional navigator gating. For aortic systolic 3D velocities, good agreement was found between all new navigator settings (scan 2–4) with the conventional navigator gating (scan 1) with best performance for Seff = 80% (mean difference = −0.01; limits od agreement = 0.23, Pearson’s ρ=0.89, p <0.001). No significant differences for image quality or 3D systolic velocities were found for 1.5T compared to 3T. Conclusions The findings of this study demonstrate the feasibility of the new navigator scheme to acquire 4D flow data with more predictable scan time while maintaining image quality and 3D velocity information, which may prove beneficial for clinical applications.

show abstract

Retrospective adaptive motion correction for navigator-gated 3D coronary MR angiography

Cited by 54 publications

References 52 publications

Coronary Vessel Wall 3-T MR Imaging with Time-resolved Acquisition of Phase-Sensitive Dual Inversion-Recovery (TRAPD) Technique: Initial Results in Patients with Risk Factors for Coronary Artery Disease

Coronary Vessel Wall 3-T MR Imaging with Time-resolved Acquisition of Phase-Sensitive Dual Inversion-Recovery (TRAPD) Technique: Initial Results in Patients with Risk Factors for Coronary Artery Disease

Coronary artery motion with the respiratory cycle during breath‐holding and free‐breathing: Implications for slice‐followed coronary artery imaging

Improved respiratory navigator gating for thoracic 4D flow MRI

Contact Info

Product

Resources

About