The application of breath hold phase velocity mapping techniques to the measurement of coronary artery blood flow velocity: Phantom data and initial <i>in vivo</i> results

Keegan, Jennifer; Firmin, David N.; Gatehouse, Peter; Longmore, D. B.

doi:10.1002/mrm.1910310509

Cited by 95 publications

(33 citation statements)

References 36 publications

(43 reference statements)

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“…It has been shown to be safe and feasible to measure flow Ϸ1 cm distal to the stent using phase-contrast techniques, 8,9 which have been well established and validated for larger vessels. 10 -12 Good accuracy and reproducibility of MR flow measurements have also been shown in small-caliber phantoms or coronary arteries in animals, [13][14][15] with close correlations with intravascular and extravascular Doppler techniques despite the complexity of such measurements in small and rapidly moving vessels. Previous investigators have used breath hold techniques to reduce breathing artifacts, which limits the maximal scan duration to 30 seconds or less.…”

Section: Discussionmentioning

confidence: 97%

Noninvasive Determination of Coronary Blood Flow Velocity With Cardiovascular Magnetic Resonance in Patients After Stent Deployment

et al. 2003

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Background-In patients with coronary artery stents, no direct noninvasive coronary artery imaging is possible with magnetic resonance (MR). A well-established method for the assessment of the functional significance of a coronary lesion is the measurement of coronary flow reserve by invasive intracoronary Doppler. The purpose of the study was to determine coronary flow velocity reserve (CFVR) with MR after stent deployment. Methods and Results-Thirty-eight patients after successful PTCA and stent deployment were included. CFVR was measured perpendicular to the artery distal to the stent using phase-contrast velocity quantification at rest and during adenosine-stimulated hyperemia with a 1.5T MR tomograph (ACS NT, Philips). Measurements were repeated after 3 months and compared with invasive coronary angiography. In 18 patients, additional invasive Doppler flow measurements were obtained. CFVR could be determined in 29 of 38 (76%) of the patients. After 3 months, significant differences were obtained between coronary arteries with and without restenosis. Using a threshold of 1.2, a sensitivity of 83% with a specificity of 94% was achieved for Ն75% stenoses. CFVR with CMR was similar to Doppler results (rϭ0.87), with a mean relative difference of 7.5%. Conclusions-In patients with preserved coronary microcirculating vasoreactivity that are suitable for MR coronary angiography and flow assessments, CMR measures of coronary blood flow velocities reserve may be used to detect in-stent restenosis.

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Section: Discussionmentioning

confidence: 97%

Noninvasive Determination of Coronary Blood Flow Velocity With Cardiovascular Magnetic Resonance in Patients After Stent Deployment

et al. 2003

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“…27 Although Doppler transesophageal echocardiography has been used to estimate stenosis severity in the proximal LAD coronary artery, 28 it is associated with some patient discomfort (because it requires esophageal intubation), and localization of the Doppler sample volume distal to a stenosis or a major side branch is difficult. 29 Two-and 3-dimensional MRI techniques have been used to visualize coronary arteries, but relatively low spatial resolution (particularly when compared with contrast coronary angiography), 30 difficulty with algorithms used in reconstruction (for 3-dimensional techniques), 31 and MRI artifacts 32 have led to imprecise quantitation of stenosis severity. Using the gradient-echo techniques alone in this study, MRI investigators were able to identify stenosis location but not accurately determine stenosis severity.…”

Section: Discussionmentioning

confidence: 99%

Visualization and Functional Assessment of Proximal and Middle Left Anterior Descending Coronary Stenoses in Humans With Magnetic Resonance Imaging

et al. 1999

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Background-Coronary artery bypass grafting improves survival in patients with Ͼ70% luminal diameter narrowing of the 3 major epicardial coronary arteries, particularly if there is involvement of the proximal portion of the left anterior descending (LAD) coronary artery. Measurement of coronary flow reserve can be used to identify functionally important luminal narrowing of the LAD artery. Although magnetic resonance imaging (MRI) has been used to visualize coronary arteries and to measure flow reserve noninvasively, the utility of MRI for detecting significant LAD stenoses is unknown. Methods and Results-Thirty subjects (23 men, 7 women, age 36 to 77 years) underwent MRI visualization of the left main and LAD coronary arteries as well as measurement of flow in the proximal, middle, or distal LAD both at rest and after intravenous adenosine (140 g/kg per minute). Immediately thereafter, contrast coronary angiography and when feasible, intracoronary Doppler assessments of coronary flow reserve, were performed. There was a statistically significant correlation between MRI assessments of coronary flow reserve and (a) assessments of coronary arterial stenosis severity by quantitative coronary angiography and (b) invasive measurements of coronary flow reserve (PϽ0.0001 for both). In comparison to computer-assisted quantitative coronary angiography, the sensitivity and specificity of MRI for identifying a stenosis Ͼ70% in the distal left main or proximal/middle LAD arteries was 100% and 83%, respectively. Conclusions-Noninvasive MRI measures of coronary flow reserve correlated well with similar measures obtained with the use of intracoronary Doppler flow wires and predicted significant coronary stenoses (Ͼ70%) with a high degree of sensitivity and specificity. MRI-based measurement of coronary flow reserve may prove useful for identification of patients likely to obtain a survival benefit from coronary artery bypass grafting. (Circulation. 1999;99:3248-3254.)

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“…Several studies have dealt with the accuracy and reproducibility of flow measurements in small-caliber phantoms or coronary arteries in animals (22)(23)(24) and have shown close correlations of the MR measurements with intra-and extravascular Doppler techniques. However, differences between the Doppler and the MR method varied considerably in a study by Hoffman et al (24).…”

Section: Discussionmentioning

confidence: 99%

Noninvasive determination of coronary blood flow velocity with magnetic resonance imaging: Comparison of breath-hold and navigator techniques with intravascular ultrasound

et al. 1999

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The aim of this study was to evaluate two different magnetic resonance (MR) techniques for the noninvasive assessment of intracoronary blood flow. Coronary blood flow velocities were measured invasively in 26 angiographically normal segments of 12 patients. Noninvasive measurements were performed in identical segments with two MR techniques using a 1.5 T MR tomograph (ACS NT, Philips). A single breath‐hold technique (temporal resolution: 140 msec) and a similar non‐breath‐hold technique with prospective navigator correction and improved temporal resolution (45 msec) were used. Maximal coronary flow velocities determined by MR correlated closely with invasive measurements (breath‐hold: r = 0.70; navigator: r = 0.86); however, a significant underestimation of the MR measurements was found (slope = 0.33 and 0.37). The relative difference from the invasive method was lower for the navigator technique compared with the breath‐hold technique (P < 0.02). Both MR techniques allow the determination of coronary blood flow velocities. The higher temporal resolution and shorter acquisition window of navigator‐corrected non‐breath‐hold techniques lead to increased accuracy. This approach is a further step toward the diagnostic use of MR flow measurements in coronary artery disease. Magn Reson Med 41:544–549, 1999. © 1999 Wiley‐Liss, Inc.

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The application of breath hold phase velocity mapping techniques to the measurement of coronary artery blood flow velocity: Phantom data and initial in vivo results

Cited by 95 publications

References 36 publications

Noninvasive Determination of Coronary Blood Flow Velocity With Cardiovascular Magnetic Resonance in Patients After Stent Deployment

Noninvasive Determination of Coronary Blood Flow Velocity With Cardiovascular Magnetic Resonance in Patients After Stent Deployment

Visualization and Functional Assessment of Proximal and Middle Left Anterior Descending Coronary Stenoses in Humans With Magnetic Resonance Imaging

Noninvasive determination of coronary blood flow velocity with magnetic resonance imaging: Comparison of breath-hold and navigator techniques with intravascular ultrasound

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