MR imaging of the aortic root and proximal coronary arteries

Paulin, Sven; Schulthess, Gustav K. von; Fossel, Eric T.; Krayenbuehl, H. P.

doi:10.2214/ajr.148.4.665

Cited by 135 publications

(34 citation statements)

References 18 publications

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“…Standard electrocardiographically (ECG) gated spin-echo and gradient-echo cine images only occasionally show portions of the coronary arteries, and these images are not adequate for detailed evaluation. 23 Even a 1-second acquisition is too long to freeze cardiac motion. Instead, the acquisition can be "segmented" into blocks of phase-encoding steps, which are then interleaved to create an image.…”

Section: Mra: Technical Considerationsmentioning

confidence: 99%

“…Early attempts at coronary MRA with conventional spin-echo MR were met with limited success. In 1984, Lieberman et al 170 were able to visualize portions of the coronaries in only 7 of 23 patients, whereas Paulin and colleagues 23 identified the origin of the left main coronary artery in all 6 subjects examined and the RCA ostium in 4 of the 6 individuals. No coronary stenoses were identified in either report.…”

Section: Mra Of the Coronary And Pulmonary Arteriesmentioning

confidence: 99%

See 1 more Smart Citation

Magnetic Resonance Angiography

Yucel¹,

Anderson²,

Edelman³

et al. 1999

Circulation

126

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Section: Mra: Technical Considerationsmentioning

confidence: 99%

Section: Mra Of the Coronary And Pulmonary Arteriesmentioning

confidence: 99%

Magnetic Resonance Angiography

Yucel¹,

Anderson²,

Edelman³

et al. 1999

Circulation

126

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“…The LCX graft was, on occasion, difficult to distinguish from the coronary sinus at the level of the left ventricle. Other authors have commented on structures that may be confused with bypass grafts or native coronary arteries, including the pericardial reflections, coronary veins, and postsurgical defects in the pericardium.4 9 Gomes et al 4 commented on the importance of following bypass grafts through successive images from the position near native coronary In this study we considered grafts known to have been placed at the time of surgery that were not seen by MR as occluded, although it is possible that if flow through a native graft is slow it will not have the typical appearance of a signal-free lumen. Blood vessels are visualized with the spin-echo technique by the appearance of a signal-free lumen10 because the spins of moving blood that are pulsed move out of the imaging plane.…”

Section: Discussionmentioning

confidence: 99%

Magnetic resonance imaging to evaluate patency of aortocoronary bypass grafts.

et al. 1987

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To assess the efficacy of magnetic resonance (MR) imaging in evaluating graft patency after coronary bypass surgery, 20 patients who had prior surgery (average 5.5 years, range 1.5 to 14) and recent cardiac catheterization because of chest pain were studied. No patient had surgical intervention or change in symptoms in the time interval between catheterization and MR imaging. These 20 patients had a total of 47 grafts, defined as proximal anastomoses: 20 to the left anterior descending or diagonal artery (LAD), 13 to the left circumflex artery marginal branches (LCX), and 14 to the right coronary artery or posterior descending artery (RCA). The patients underwent cardiac and respiratory gated MR scans in a 0.5 tesla magnet with an echo time of 22 msec and two repetitions in a 128 x 256 matrix. In-plane resolution was 2.7 mm. Every patient had a scan in the transaxial plane and some underwent scanning in the sagittal and coronal planes as well. A graft was considered patent by MR when a signal-free lumen was visualized in an anatomic position consistent with that of a bypass graft, had a lumen larger than the native vessels, was seen on more than one slice, and was seen at a level higher than that of the native vessels. If a known graft was not seen it was considered occluded. The scans were interpreted by consensus of two physicians aware of the operative but not the cardiac catheterization data. Twenty-six of 29 patent grafts and 13 of 18 occluded grafts were correctly classified (sensitivity 90%, specificity 72%). Eighteen of 20 (90%) LAD grafts, 11 of 14 (79%) RCA grafts, and 11 of 13 (85%) LCX grafts were correctly classified. When the results from three patients with technically poor studies because of poor cardiac gating were excluded, the overall sensitivity and specificity were 92% and 85%, respectively. This study demonstrates the high sensitivity and moderate specificity of MR for evaluating the patency of coronary artery bypass grafts, particularly LAD grafts. Circulation 76, No. 4, 786-791, 1987. INCREASING NUMBERS of patients with previous coronary artery bypass surgery

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“…Since the first report in 1987, technological advances in coronary MRA have led to enhanced spatial resolution and the possibility of imaging while the patient is breathing freely. 43 However, due to breathing and cardiac motion, tortuosity and small vessels, coronary MRA is still technically difficult for the confident determination of the presence as well as the severity of coronary stenosis. Great improvement was achieved during the last 5 years with the new generation of magnetic resonance platforms.…”

Section: Cardiovascular Mrimentioning

confidence: 99%

New imaging techniques for diagnosing coronary artery disease

Escolar

Weigold

Fuisz

et al. 2006

CMAJ

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I nvasive coronary angiography is the standard clinical means for depicting the coronary arteries and is the "gold standard" for diagnosing coronary artery disease (CAD). Since its implementation over 30 years ago, more than 2 million coronary angiograms have been made yearly in North America. Coronary angiography requires high-level technical expertise and technology, which makes it relatively expensive and limits it to a select population. Angiography also has its limitations, since only the lumen is displayed ("luminology") and the information it provides about the coronary plaque is not extensive. However, new tomographic methods for cardiovascular imaging such as intravascular ultrasonography (IVUS), coronary CT angiography and MRI can assess the atherosclerotic plaques responsible for early, "silent" CAD. In this article, we review the current and potential future clinical applications of these 3 tools for the visual detection of atherosclerotic CAD. Intravascular ultrasonographyIVUS has become a powerful complementary tool to measure and characterize coronary vessels and atherosclerotic plaques. An invasive procedure, IVUS produces images with a small ultrasound transducer mounted on a catheter similar to the standard catheters employed in coronary angioplasty. The catheter is advanced over the wire inside the coronary artery until it reaches a position distal to the segment to be studied. A series of tomographic images of the coronary artery are obtained as the catheter is slowly pulled back. Each IVUS image displays a 360°cross-sectional view of the layers of the coronary artery (intima, media and adventitia) as well as the lumen (Fig. 1A,B). Modern devices can perform 3-dimensional reconstructions online that provide information about the length, volume and reference landmarks of a plaque.Standard radiographic coronary angiography provides a single-plane "shadow" of the vascular lumen; its ability to accurately and reproducibly measure the degree of stenosis and to characterize plaque morphology is limited.1-3 Extensive experience in our and other centres has shown that IVUS is a safe, accurate and reproducible alternative method for assessing the severity and morphology of lesions.4,5 The types of plaques detectable by IVUS are summarized in Box 1. Clinical useThe best-studied clinical application of IVUS is in the placement of stents into coronary vessels (Fig. 1C,D, Fig. 2, Fig. 3). Stenting has revolutionized the treatment of atherosclerotic CAD. Restenosis inside the stent, which occurs in 5%-20% of cases (depending on the complexity of the lesion and underlying risk factors), nevertheless remains a major shortcoming. IVUS has played an important role in the understanding of stent failures.In-stent restenosis is typically caused by neointimal hyperplasia: new fibrotic tissue that grows inside the stent and obstructs the lumen. Serial IVUS studies performed in cases of bare-metal stent failure have shown that underexpansion of the stent is an important cause of early failure.6 If the stent is poorl...

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MR imaging of the aortic root and proximal coronary arteries

Cited by 135 publications

References 18 publications

Magnetic Resonance Angiography

Magnetic Resonance Angiography

Magnetic resonance imaging to evaluate patency of aortocoronary bypass grafts.

New imaging techniques for diagnosing coronary artery disease

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