Combined Assessment of Myocardial Perfusion and Late Gadolinium Enhancement in Patients After Percutaneous Coronary Intervention or Bypass GraftsA Multicenter Study of an Integrated Cardiovascular Magnetic Resonance Protocol
Peter Bernhardt, MD*, ,*,
Jochen Spiess, MD*,
Benny Levenson, MD ,
Günter Pilz, MD,
Berthold Höfling, MD,
Vinzenz Hombach, MD*,
Oliver Strohm, MD
* Department of Internal Medicine II, Cardiovascular MRI Unit, University of Ulm, Ulm, Germany
CMR-Center at the Hospital Agatharied, Academic Teaching Hospital of the University of Munich, Hausham, Germany
Cardiac Praxis, Catheterization Laboratory at the St.-Gertrauden-Hospital, Berlin, Germany
Stephenson Cardiovascular MR Centre, University of Calgary, Calgary, Canada
 |
Abstract
|
|---|
Objectives: We sought to assess the accuracy of an integrated cardiac magnetic resonance (CMR) protocol for the diagnosis of relevant coronary artery or bypass graft stenosis in patients with suspected coronary artery disease (CAD) or with previously performed percutaneous coronary intervention (PCI) or coronary bypass graft surgery (CABG).
Background: CMR is suitable for diagnosing inducible myocardial ischemia in patients with suspected CAD and has been proven to be a helpful diagnostic tool for decision of further treatment. However, little is known about its diagnostic accuracy in patients with known CAD who previously were treated by PCI or CABG.
Methods: A total of 477 patients with suspected CAD, 236 with previous PCI, and 110 after CABG referred for coronary X-ray angiography (CXA) underwent an integrated CMR examination before CXA. Myocardial ischemia was assessed using first-pass perfusion after vasodilator stress with adenosine (140 µg/kg/min for 3 min) using gadolinium-based contrast agents (0.1 mmol/kg). Late gadolinium enhancement (LGE) was assessed 10 min after a second contrast bolus.
Results: CXA demonstrated a relevant coronary vessel stenosis ( 70% luminal reduction) in 313 (38%) patients using quantitative coronary analysis. The combination of CMR perfusion and LGE assessment for detecting a relevant coronary stenosis in patients with suspected CAD yielded sensitivity and specificity of 0.94 and 0.87, in PCI patients 0.91 and 0.90, and in CABG patients 0.79 and 0.77, respectively.
Conclusions: A combined CMR protocol for the assessment of myocardial perfusion and LGE is feasible for the detection of relevant coronary vessel stenosis even in patients who previously were treated by PCI or CAG in a routine clinical setting. However, diagnostic accuracy is reduced in patients with CABG. This could be due to different flow and perfusion kinetic. Further studies are needed to optimize the clinical protocols especially in post-surgical patients.
Key Words: adenosine stress • cardiac magnetic resonance • perfusion • CABG • PCI
|
Abbreviations and Acronyms
| | CABG = coronary artery bypass graft | | CAD = coronary artery disease | | CMR = cardiac magnetic resonance | | CXA = coronary X-ray angiography | | LGE = late gadolinium enhancement | | PCI = percutaneous coronary artery intervention |
|
Decision of necessity of reangiography and intervention in patients with known coronary artery disease (CAD) and previous percutaneous coronary artery intervention (PCI) or coronary artery bypass graft (CABG) partly depends on the detection of myocardial ischemia and sometimes remains challenging (1). Cardiac magnetic resonance (CMR) imaging has been shown to be a safe and feasible imaging method (2) to assess myocardial ischemia with high accuracy using vasodilator and/or positive inotropic stressors as adenosine and dobutamine (3–9). Myocardial viability can be assessed noninvasively by late gadolinium enhancement (LGE) techniques with high accuracy (10–12). Recently, it has been shown that the combination of perfusion and LGE assessment increases accuracy of detecting a relevant coronary stenosis in patients with suspected, but not previously documented CAD (13,14).
However, most of the published studies have been performed in patients with suspected CAD. There is little knowledge about the ability of CMR to detect relevant coronary vessel stenosis or occlusion in patients who previously underwent PCI or CABG.
The primary aim of our study was to assess the ability of a combined CMR protocol including adenosine stress perfusion and LGE imaging to identify patients with previous PCI or CABG with a relevant coronary vessel stenosis and to compare the diagnostic performance to patients without previous PCI or CABG.
|
Methods
|
|---|
From May 2004 to October 2007, 823 patients with a clinical indication for X-ray coronary angiography (CXA) were included into the trial in three centers. Exclusion criteria were contraindication for vasodilatory stress-CMR including unstable symptoms, implanted devices, severe obstructive lung disease, and severe valvular disease. All patients were taken off vasodilator drugs and caffeine 24 h prior to CMR, and all patients gave informed consent.
CMR imaging protocol.
Imaging was performed using 1.5-T whole-body clinical magnetic resonance scanners (Intera, Philips Medical Systems, Best, the Netherlands, using a cardiac 5-element phased-array receiver coil [University of Ulm]; CV/i, GE Medical System, Milwaukee, Wisconsin, using a cardiac 4-element phased-array receiver coil [St.-Gertrauden-Hospital, Berlin], and Signa Excite, GE Medical System, using a cardiac 8-element phased-array receiver coil [Hospital Agatharied]). Heart rate, blood pressure, and oxygen saturation were monitored noninvasively during the examination.
Functional imaging of the left ventricle was done in 3 long-axis (2-, 3-, and 4-chamber view) orientation and in contiguous short-axis orientation to cover the left ventricle from the base to the apex (steady-state free precession, repetition time [TR]: 5.1 ms, echo time [TE]: 2.2 ms, field of view: 32 to 34 x 32 to 34 cm, matrix: 256 x 192, slice thickness: 8 mm, no interslice gap; acquisition in end-expirational hold).
After 3 min of adenosine infusion at a constant rate of 140 µg/kg/min, 0.1 mmol/kg gadolinium-based contrast agent (Omniscan, GE Medical Systems, Munich, Germany, or Magnevist, Bayer Schering Pharma, Berlin, Germany) was injected intravenously during a first-pass perfusion sequence as previously described (2,3,15). A hybrid echo-planar pulse sequence (TR: 6.4 to 16 ms, TE: 1.2 to 1.4 ms, flip angle: 25°, slice thickness: 10 mm, voxel size: 2.8 x 2.8 mm, 3 to 5 slices acquired at every heart beat) was used on the GE scanners as previously described (4). On the Philips scanner, a balanced fast-field echo sequence (TR: 2.6 ms, TE: 1.3 ms, saturate pre-pulse with 100-ms delay, flip angle: 50°, 40 dynamics, turbo field echo factor: 48, voxel size: 2.8 x 2.9 mm, slice thickness: 10 mm, 3 to 4 slices acquired at every heart beat) was used as previously described (5). Perfusion images were acquired in short-axis orientation using a variable gap to cover the entire left ventricle from base to apex. Breathing commands were trained with the patients prior to the study to minimize breathing-related artifacts.
Ten minutes after a second contrast agent bolus (0.1 mmol/kg), inversion-recovery gradient-echo sequences (LGE) were acquired in the same orientation as the perfusion sequence (TR: 7.1 ms, TE: 3.2 ms, voxel size: 1.2 x 1.2 mm, slice thickness: 10 mm on the GE scanners; TR: 5.6 ms, TE: 2.1 ms, voxel size: 1.2 x 1.2 mm, slice thickness: 10 mm on the Philips scanner). Additionally, a 3D LGE sequence with full coverage of the left ventricle was performed in breath hold (TR: 7.1 ms, TE: 3.2 ms, voxel size: 1.2 x 2.2 mm, slice thickness: 8 mm). TI was individually adjusted for complete nulling of the myocardium.
CMR analysis.
All CMR studies were evaluated by 1 reader of each center locally (J.S., G.P., O.S.) and a second reader for all centers (P.B.). Investigators were blinded to quantitative coronary analysis results and to patients' history and clinical symptoms.
Functional images were analyzed for left ventricular end-diastolic and end-systolic volumes by planimetry using the multislice approach. Functional images were analyzed to obtain left ventricular functional parameters as left ventricular end-diastolic and end-systolic volume, and left ventricular ejection fraction.
First-pass perfusion and LGE images were assessed visually. A relevant perfusion deficit was defined as a subendocardially beginning hypoenhancement in at least 2 adjacent segments or slices with no attributes for imaging artifacts as previously described (16). Diffuse subendocardial perfusion defects not assignable to a specific coronary supply territory were defined as unspecific; dark rim artifact (17) was not regarded as perfusion deficit using previously described criteria (18,19).
Analysis of first-pass perfusion and LGE was performed using 2 different algorithms (Fig. 1). One algorithm was similar to the one described by Klem et al. (13). The second algorithm aims to consider chronic myocardial infarction in territories supplied by previously revascularized coronary arteries. In this case, we hypothesized that presence of LGE was not considered as presence of clinically relevant stenosis of the supplying artery. Relevant myocardial ischemia was defined as mismatch between hypoenhancement on first-pass perfusion and enhancement on LGE sequences and classified as reversible ischemia. A match between first-pass deficit and LGE was considered as chronic infarction with no additional reversible ischemia. Figure 2
shows examples of stress perfusion as well as of LGE.
View larger version (22K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1 CMR Interpretation Algorithms for the Diagnosis of Coronary Artery or CABG Stenosis
Cardiac magnetic resonance (CMR) interpretation algorithms for the diagnosis of coronary artery or bypass graft stenosis. (A) Positive late enhancement consistent with prior myocardial infarction or presence of perfusion deficit during adenosine stress is interpreted as presence of coronary artery or bypass graft stenosis. (B) Perfusion deficit without corresponding late enhancement is the only condition leading to the diagnosis of coronary artery or bypass graft stenosis. CABG = coronary artery bypass graft.
|
|
View larger version (150K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2 Perfusion Defect and Absent LGE Perfusion Defect With LGE
Adenosine-stress perfusion (Ia) showing perfusion defect of the inferior and inferoseptal myocardial wall (arrows) in the absence of late gadolinium enhancement (LGE) (Ib). Perfusion deficit of the lateral wall (IIa, arrows) during adenosine with corresponding presence of LGE (IIb, arrows). The subendocardial low signal intensity in the left anterior descending and right coronary artery perfusion areas was not regarded as significant perfusion deficit, but as dark rim artifact.
|
|
Areas of ischemia and areas of LGE were assigned to the presumably supplying coronary artery using the 17-seqment model with exclusion of segment 17 (apex), as this was not visualized on the first-pass perfusion images (20).
The CMR data were analyzed for accuracy of detecting patients with relevant coronary artery or bypass graft stenosis as well as detecting.
Coronary angiography.
All coronary catheterizations and angiographies were performed as recommended by the American College of Cardiology and American Heart Association (1). Blinded analysis of invasive data, including degree of luminal narrowing of the coronary artery, was performed by independent investigators of the respective centre (J.S., B.L., B.H.). Quantitative coronary analysis was performed in all patients therefore. A stenosis 70% in a coronary artery or in a bypass graft with a diameter 2 mm was considered significant. A stenotic native vessel with corresponding nonstenotic bypass graft was not considered for ischemia.
Statistical analysis.
All statistical analysis was performed with commercially available statistic software (StatView 5, SAS Institute, Cary, North Carolina). Data are reported as the mean ± standard deviation. Continuous variables between groups were compared using the t-test for unpaired observations. Nominal data were compared using the Fisher exact test. Ordinal variables were compared using Wilcoxon signed rank test for matched pairs. The McNemar test was used for comparison of the 2 analysis algorithms. In all cases, a p value < 0.05 was considered statistically significant.
|
Results
|
|---|
A total of 876 patients were screened for inclusion into the study. Fifty-three patients were not included due to claustrophobia (n = 27), contraindication for adenosine (n = 21) or refusal to give consent (n = 5). Thus, 823 patients (629 [76%] male) formed the study population. 477 (58%) patients with suspected CAD, 236 (29%) with previous PCI, and 110 (13%) with previous CABG formed the different study groups. CMR studies were performed 8 ± 5 days before CXA.
Clinical indication for CXA was relevant angina (74.4%), positive stress test (other than CMR) (31%), and/or other abnormalities (8.1%), as, e.g., dyspnea, considered as angina equivalent, new left bundle brunch block, or new nonsustained ventricular tachycardia.
Mean time between PCI or CABG and CMR examination was 314 ± 231 days and 423 ± 275 days, respectively. Patients' characteristics are given in Table 1.
View this table:
[in this window]
[in a new window]
|
Table 1 Patients' Characteristics and Hemodynamics Data and Comparison of Patients With Angiographically Diagnosed Stenosis of a Coronary Artery or Bypass Graft
|
|
No major or minor complications occurred; all patients could complete the entire protocol. Transient AV-block was observed in 81 (9%) patients, but did not require specific treatment or cessation of the study.
Quality of perfusion images was sufficient for further analysis in all patients. In 138 (16.8%) patients, noncritical artifacts could be seen on perfusion imaging. These artifacts were graded to be motion artifacts due to breathing in 51 cases, dark rim artifacts in 49 cases, and ghosting artifacts in 38 cases. A total of 185 (0.9%) segments had to be excluded from visual analysis due to severe artifacts. However, no study had to be excluded due to insufficient image quality. In 23 (2.8%) patients, image quality of the LGE sequences was insufficient for analysis.
CMR and diagnostic performance.
Volumetric data of the left ventricle are given in Table 1. Patient groups did not differ significantly for ventricle functional parameters. Patients with and without coronary stenosis did not differ for these parameters, either.
Perfusion deficits were detected in 417 (50.7%) patients in the first-pass perfusion. Two hundred of 477 (41.9%) patients with perfusion deficits during adenosine-stress perfusion were found in the patient group with suspected CAD, 129 of 236 (54.7%) in the PCI and 88 of 110 (80.0%) in the CABG group. LGE could be visualized in 312 (37.9%) patients with a transmural extent in 152 patients; 262 of these had a history of myocardial infarction.
CXA revealed relevant coronary artery stenosis or chronic occlusion in 173 (36%) patients with suspected CAD, in 69 (29%) PCI, and in 71 (65%) CABG patients.
Algorithm A performed best in patients with suspected CAD and yielded a sensitivity of 0.93, a specificity of 0.87, a positive predictive value of 0.81, a negative predictive value of 0.96, and an overall accuracy of 0.89. In patients with PCI and CABG, we observed better CMR interpretation, with algorithm B resulting in a sensitivity of 0.88 and 0.73, a specificity of 0.90 and 0.77, a positive predictive value of 0.79 and 0.85, a negative predictive value of 0.95 and 0.61, and an overall accuracy of 0.91 and 0.75, respectively.
Diagnostic performance of CMR with both analysis algorithms for all patient groups and subanalysis for 1- or multiple-vessel disease is given in Table 2. Furthermore, diagnostic performance subanalysis of both CMR algorithms in all patient groups for the left anterior descending, left circumflex, and right coronary artery perfusion territories as well as for arterial, venous, and mixed bypass grafts in the CABG group is provided in Table 2.
View this table:
[in this window]
[in a new window]
|
Table 2 Diagnostic Accuracy of Both CMR Algorithms in All Patient Groups and Subanalysis for 1- or Multiple-Vessel Disease
|
|
Patients with coronary artery or bypass graft stenosis 70% had significantly more segments with LGE (p < 0.0001) and had significantly more often transmural extent than patients without coronary artery stenosis (p = 0.0074). There were no differences in age, sex, cardiovascular risk factors, or left ventricular functional parameters between patients with and without angiographically detected stenosis. Comparison of patients with and without coronary artery stenosis as detected by CXA is given in Table 3.
In 3 of 9 (33%) patients with false positive CMR interpretation, the perfusion deficit observed affected only basal myocardial segments. In 8 of 19 (42%) patients with false negative CMR results, we found perfusion deficit and LGE match, thus this was interpreted as nonreversible ischemia in chronic myocardial ischemia.
|
Discussion
|
|---|
The primary finding of our study is that an integrated CMR examination using first-pass perfusion and LGE is a feasible method to detect myocardial ischemia and irreversible myocardial injuries in patients with previous coronary artery intervention or CABG with high sensitivity, specificity and overall accuracy.
Comparing the amount of inducible ischemia (assessed by vasodilator stress first-pass perfusion) and the amount of irreversible ischemic damage (as assessed by LGE in the same image orientation) allows predicting a relevant coronary artery stenosis that would benefit from revascularization. A "match" between the amount of inducible ischemia and LGE is considered a completed myocardial infarct and thus would not require revascularization of the supplying vessel. To account for the presence of irreversible injury in segments with inducible ischemia, we developed an analysis algorithm and correlated the predictive values to invasive coronary angiography.
Only the visualization of inducible ischemia in non-LGE myocardium would predict a clinically relevant coronary vessel stenosis and mandate for revascularization. We therefore compiled our second analysis algorithm to identify patients with inducible myocardial ischemia and chronic myocardial infarction. The better performance of this algorithm strengthens the thesis about necessity of an analysis and interpretation algorithm that considers chronic myocardial infarction.
Assessment of a relevant restenosis or new stenosis in an artery after intervention has been described using different diagnostic tools. A recent meta-analysis proved exercise treadmill testing to be a rather poor diagnostic test to identify the presence of graft stenosis, yielding a sensitivity of 45% and a specificity of 82% (21–24). Dobutamine stress echocardiography with contrast-enhanced perfusion imaging has been shown to have a sensitivity of 73% and a specificity of 75% (25) for the evaluation of coronary artery stenosis. Nuclear medicine techniques have also been evaluated for the detection of restenosis in patients after PCI. Single-photon emission computed tomography (SPECT) imaging has been shown to have a sensitivity of 93% and a specificity of 77% for detection of restenosis in patients after PCI (23); however, SPECT is known to suffer from attenuation artifacts (26) and exposes patients to unwanted radiation.
CMR offers the ability to assess different aspects of CAD in a combined protocol; it has been shown to quantify ventricular functional parameters (27,28), assess first-pass perfusion during stress (2–8,13–15), and allow for noninvasive assessment of myocardial viability (10–15,20,29) in a single study. Recent studies have shown that CMR provides a high accuracy in detecting myocardial perfusion defects in patients with suspected CAD (3–6,8,13,14).
We could demonstrate that patients after bypass can be assessed with CMR, but with a lower diagnostic yield. Delayed contrast appearance in myocardial tissue during stress perfusion study could have different etiologies, such as post-stenotic pressure reduction in the supplying coronary artery, altered coronary artery anatomy with changed flow properties, slower flow and/or longer transit time of the contrast bolus through bypass grafts. A comparison between radial artery grafts and longer saphenous venous bypass grafts found significant different flow characteristics and flow response (29). These data strengthen the hypothesis of different flow characteristics in different bypass types that could possibly cause different myocardial perfusion (30) and thus be a limitation in the correct assessment of graft patency.
This may be a universal limitation for all stress methods after bypass grafts and may mandate a baseline-stress study immediately after surgery. Supporting this theory is a study by Fenchel et al. (31) that provided information on the success of interventional procedures in 18 patients performing stress-CMR as a baseline after intervention. The lack of a "baseline" study could explain the lower specificity of CMR performance in CABG patients in our study.
The presence of significant collateral flow in patients with multivessel CAD could account for the lower sensitivity in our patient group after CAPB; these patients had a higher rate of multiple-vessel disease and presumably more often developed system of collateral flow. A study by Becker et al. (32) showed that stenoses of the coronary vessels supplying collateral flow to ischemic regions are necessary for the occurrence of coronary steal phenomenon. Another recent study detected coronary steal in only one-third of patients with chronic total coronary occlusion (33). These findings strengthen the higher rate of false negative findings in our CABG group and thus could explain the lower sensitivity of CMR performance.
In 33% of our false positive CMR interpretations, we observed myocardial ischemia affecting only the basal myocardial segments. A possible explanation could be a distal anastomosis of the bypass graft, restricting flow to the basal segments in case of a proximal stenosis or occlusion. Thus, in case of proximal stenosis or occlusion of the native coronary artery, a perfusion of the basal segments could be restricted.
Study limitations.
The patient groups included in the study had a high pre-test probability for the presence of CAD, as they all had a clinical indication for invasive coronary angiography. Thus, the results of our study may not be easily transferrable to the general population or to patients with low or medium pre-test probability.
The use of different CMR systems and perfusion sequences in the 3 centers could be a possible limitation to our study. However, we did not observe significant differences regarding CMR performance between our centers.
Another possible limitation is the presence of artifacts in 16.8% patients. However, less than 1% of stress perfusion images and less than 3% of LGE images had to be excluded from analysis due to insufficient image quality.
|
Conclusions
|
|---|
Our data show that CMR is suitable for noninvasive detection of relevant coronary artery stenosis in patients with suspected CAD, including those with previous PCI or CABG. The combined assessment of inducible ischemia and reversible ischemia in an integrated CMR protocol allows predicting the presence of a clinically relevant coronary artery and/or bypass graft stenosis. In patients with previous CABG, sensitivity, specificity, and accuracy of CMR is reduced in comparison to the other patient groups. Further studies are warranted to determine whether a quantitative assessment in this patient group could improve the accuracy of the test.
|
Footnotes
|
|---|
Dr. Strohm is a shareholder in and consultant for Circle Cardiovascular Imaging Inc., Calgary, Canada.
* Reprint requests and correspondence: Dr. Peter Bernhardt, Department of Internal Medicine II, University of Ulm, 89077 Ulm, Germany (Email: peter.bernhardt{at}uniklinik-ulm.de).
Manuscript received February 1, 2009;
revised manuscript received April 24, 2009,
accepted May 21, 2009.
|
REFERENCES
|
|---|
- Scanion PJ, Faxon DP, Audet AM, et al. ACC/AHA guidelines for coronary angiography A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Coronary Angiography). Developed in collaboration with the Society for Cardiac Angiography and Interventions. Circulation 1999;99:2345-2357.[Free Full Text]
- Bernhardt P, Steffens M, Kleinertz K, et al. Safety of adenosine stress magnetic resonance imaging using a mobile cardiac magnetic resonance system J Cardiovasc Magn Reson 2006;8:475-478.[CrossRef][Web of Science][Medline]
- Giang TH, Nanz D, Coulden R, et al. Detection of coronary artery disease by magnetic resonance myocardial perfusion imaging with various contrast medium doses: first European multi-centre experience Eur Heart J 2004;25:1657-1665.[Abstract/Free Full Text]
- Schwitter J, Nanz D, Kneifel S, et al. Perfusion in coronary artery disease by magnetic resonance: a comparison with positron emission tomography and coronary angiography Circulation 2001;103:2230-2235.[Abstract/Free Full Text]
- Nagel E, Klein C, Paetsch I, et al. Magnetic resonance perfusion measurements for the noninvasive detection of coronary artery disease Circulation 2003;108:432-437.[Abstract/Free Full Text]
- Ishida N, Sakuma H, Motoyasu M, et al. Noninfarcted myocardium: correlation between dynamic first-pass contrast-enhanced myocardial MR imaging and quantitative coronary angiography Radiology 2003;229:209-216.[Abstract/Free Full Text]
- Pennell DJ. Cardiovascular magnetic resonance and the role of adenosine pharmacologic stress Am J Cardiol 2004;94(Suppl):26D-32D.[Web of Science][Medline]
- Lee DC, Simonetti OP, Harris KR, et al. Magnetic resonance versus radionuclide pharmacological stress perfusion imaging for flow limiting stenoses of varying severity Circulation 2004;110:48-65.
- Kwong RY, Schussheim AE, Rekhraj S, et al. Detecting acute coronary syndrome in the emergency department with cardiac magnetic resonance imaging Circulation 2003;107:531-537.[Abstract/Free Full Text]
- Klein C, Nekolla SG, Bengel FM, et al. Assessment of myocardial viability with contrast-enhanced magnetic resonance imaging: comparison with positron emission tomography Circulation 2002;105:162-167.[Abstract/Free Full Text]
- Wagner A, Mahrholdt H, Holly TA, et al. Contrast-enhanced MRI and routine single photon emission computed tomography (SPECT) perfusion imaging for detection of subendocardial myocardial infarcts: an imaging study Lancet 2003;361:374-379.[CrossRef][Web of Science][Medline]
- Christiansen JP, Edwards C, Sinclair T, et al. Detection of myocardial scar by contrast-enhanced cardiac magnetic resonance imaging in patients with troponin-positive chest pain and minimal angiographic coronary artery disease Am J Cardiol 2006;97:768-771.[CrossRef][Web of Science][Medline]
- Klem I, Heitner JF, Shah DJ, et al. Improved detection of coronary artery disease by stress perfusion cardiovascular magnetic resonance with the use of delayed enhancement infarction imaging J Am Coll Cardiol 2006;47:1630-1638.[Abstract/Free Full Text]
- Cury RC, Cattani CAM, Gabure LAG, et al. Diagnostic performance of stress perfusion and delayed-enhancement MR imaging in patients with coronary artery disease Radiology 2006;240:39-45.[Abstract/Free Full Text]
- Wöhrle J, Nusser T, Merkle N, et al. Myocardial perfusion reserve in cardiovascular magnetic resonance: correlation to coronary microvascular dysfunction J Cardiovasc Magn Reson 2006;8:781-787.[CrossRef][Web of Science][Medline]
- Bernhardt P, Levenson B, Albrecht A, Engels T, Strohm O. Detection of cardiac small vessel disease by adenosine-stress magnetic resonance Int J Cardiol 2007;121:261-266.[CrossRef][Medline]
- Di Bella EVR, Parker DL, Sinusas AJ. On the dark rim artifact in dynamic contrast-enhanced MRI myocardial perfusion studies Magn Reson Med 2005;54:1295-1299.[CrossRef][Web of Science][Medline]
- Arai AE. Magnetic resonance first-pass myocardial perfusion imaging Top Magn Reson Imaging 2000;11:383-398.[CrossRef][Medline]
- Barkhausen J, Hunold P, Jochims M, Debatin JF. Imaging of myocardial perfusion with magnetic resonance J Magn Reson Imaging 2004;19:750-757.[CrossRef][Web of Science][Medline]
- Cerqueria MD, Weissman NJ, Dilsizian V, et al. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: a statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association Circulation 2002;105:539-542.[Free Full Text]
- Bengston JR, Mark DB, Honan MB, et al. Detection of restenosis after elective percutaneous transluminal coronary angioplasty using the exercise treadmill test Am J Cardiol 1990;65:28-34.[Web of Science][Medline]
- Honan MB, Bengston JR, Pryor DB, et al. Exercise treadmill testing is a poor predictor of anatomic restenosis after angioplasty for acute myocardial infarction Circulation 1989;80:1585-1594.[Abstract/Free Full Text]
- Hecht HS, Shaw RE, Bruce TR, Ryan C, Stertzer SH, Myler RK. Usefulness of tomographic Thallium-201 imaging for detection of restenosis after percutaneous transluminal coronary angioplasty Am J Cardiol 1990;66:1314-1318.[CrossRef][Web of Science][Medline]
- Chin AS, Goldmann LE, Eisenberg MJ. Stress testing after coronary artery bypass graft surgery: a meta-analysis Can J Cardiol 2003;19:802-808.[Web of Science][Medline]
- Elhendy A, Tsutsui JM, O'Leary EL, Xie F, Majeed F, Porter TR. Evaluation of restenosis and extend of coronary artery disease in patients with previous coronary interventions by dobutamine stress real-time myocardial contrast perfusion imaging Heart 2006;92:1480-1483.[Abstract/Free Full Text]
- Hendel RC, Berman DS, Cullom SJ, et al. Multicenter clinical trial to evaluate the efficacy of correction for photon attenuation and scatter in SPECT myocardial perfusion imaging Circulation 1999;99:2742-2749.[Abstract/Free Full Text]
- Bellenger NG, Burgess MI, Ray SG, et al. Comparison of left ventricular ejection fraction and volumes in heart failure by echocardiography, radionuclide ventriculography and cardiovascular magnetic resonance; are they interchangeable? Eur Heart J 2000;21:1387-1396.[Abstract/Free Full Text]
- Beygui F, Furber A, Delépine S, et al. Routine breath-hold gradient echo MRI-derived right ventricular mass, volumes and function: accuracy, reproducibility and coherence study Int J Cardiovasc Imaging 2004;20:509-516.[CrossRef][Web of Science][Medline]
- Kim RJ, Fieno DS, Parrish TB, et al. Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function Circulation 1999;100:1992-2002.[Abstract/Free Full Text]
- Chong WCF, Collins P, Webb CM, et al. Comparison of flow characteristics and vascular reactivity of radial artery and long saphenous vein grafts J Cardiothorac Surg 2006;1:4.[CrossRef][Medline]
- Fenchel M, Franow A, Stauder NI, et al. Myocardial perfusion after angioplasty in patients suspected of having single-vessel coronary artery disease: improvement detected at rest-stress first-pass perfusion MR imaging–initial experience Radiology 2005;237:67-74.[Abstract/Free Full Text]
- Becker LC. Conditions for vasodilator-induced coronary steal in experimental myocardial ischemia Circulation 1978;57:1103-1110.[Abstract/Free Full Text]
- Werner GS, Figulla HR. Direct assessment of coronary steal and associated changes of collateral hemodynamics in chronis total coronary occlusions Circulation 2002;106:435-440.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
S. Achenbach, C. M. Kramer, W. A. Zoghbi, and V. Dilsizian
The Year in Coronary Artery Disease
J. Am. Coll. Cardiol. Img.,
October 1, 2010;
3(10):
1065 - 1077.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
Top
Abstract
Methods