[Show abstract][Hide abstract] ABSTRACT: Purpose of this study was to assess the additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress Cardiac-MR (CMR). Dobutamine Stress CMR was performed in 115 patients with an inconclusive diagnosis of myocardial ischemia on a 1.5 T system (Magnetom Avanto, Siemens Medical Systems). Three short-axis cine and grid series were acquired during rest and at increasing doses of dobutamine (maximum 40 microg/kg/min). On peak dose dobutamine followed immediately by a first pass myocardial perfusion imaging sequence. Images were graded according to the sixteen-segment model, on a four point scale. Ninety-seven patients showed no New (Induced) Wall Motion Abnormalities (NWMA). Perfusion imaging showed absence of perfusion deficits in 67 of these patients (69%). Perfusion deficits attributable to known previous myocardial infarction were found in 30 patients (31%). Eighteen patients had NWMA, indicative for myocardial ischemia, of which 14 (78%) could be confirmed by a corresponding perfusion deficit. Four patients (22%) with NWMA did not have perfusion deficits. In these four patients NWMA were caused by a Left Bundle Branch Block (LBBB). They were free from cardiac events during the follow-up period (median 13.5 months; range 6-20). Addition of first-pass myocardial perfusion imaging during peak-dose dobutamine stress CMR can help to decide whether a NWMA is caused by myocardial ischemia or is due to an (inducible) LBBB, hereby preventing a false positive wall motion interpretation.
The International Journal of Cardiovascular Imaging 02/2008; 24(1):69-76. · 2.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
To determine whether the distribution of coronary artery calcium (CAC) is associated with the location of myocardial ischemia during dobutamine MRI, detected as wall motion abnormalities (WMAs).
METHOD AND MATERIALS
129 patients clinically suspected of myocardial ischemia were included in the study. 114 patients (mean age, 63.5 years; 62% men) underwent dobutamine stress MRI for detecting WMAs and 16-row multidetector CT for calcium scoring. The calcium score was calculated by Agatston’s method. The distribution of CAC was correlated to the location of WMAs.
In patients with WMAs, the median calcium score was 359 (25th and 75th quartile, 208, 1501). Inducible WMAs were present in 22 patients, while rest WMAs were observed in 25 patients, including 6 who also had inducible WMAs. Of the patients with inducible WMAs, 36% had experienced a previous myocardial infarction, compared to 92% of the patients with rest WMAs. In 50.0% of the WMA cases, relatively most of the CAC was present in the left anterior descending coronary artery, in 18.4% in the right coronary artery, in 15.8% in the left circumflex artery, and in 15.8%, CAC was more diffuse. In 85.7% of patients with inducible WMAs and in 69.6% of patients with rest WMAs, the location of WMA corresponded with the CAC distribution (both p<0.05).
In patients suspected of myocardial ischemia, the distribution of CAC shows a significant association with the location of both inducible WMAs and rest WMAs during dobutamine MRI.
Radiological Society of North America 2005 Scientific Assembly and Annual Meeting; 11/2005
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine whether a coronary artery calcium (CAC) score of less than 11 can reliably rule out myocardial ischemia detected by dobutamine cardiovascular magnetic resonance imaging (CMR) in patients suspected of having myocardial ischemia. In 114 of 136 consecutive patients clinically suspected of myocardial ischemia with an inconclusive diagnosis of myocardial ischemia, dobutamine CMR was performed and the CAC score was determined. The CAC score was obtained by 16-row multidetector compued tomography (MDCT) and was calculated according to the method of Agatston. The CAC score and the results of the dobutamine CMR were correlated and the positive predictive value (PPV) and the negative predictive value (NPV) of the CAC score for dobutamine CMR were calculated. A total of 114 (87%) of the patients were eligible for this study. There was a significant correlation between the CAC score and dobutamine CMR (p<0.001). Patients with a CAC score of less than 11 showed no signs of inducible ischemia during dobutamine CMR. For a CAC score of less than 101, the NPV and the PPV of the CAC score for the outcome of dobutamine CMR were, respectively, 0.96 and 0.29. In patients with an inconclusive diagnosis of myocardial ischemia a MDCT CAC score of less than 11 reliably rules out myocardial ischemia detected by dobutamine CMR.
European Radiology 07/2005; 15(6):1128-34. · 4.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) ( P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event ( P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy.
European Radiology 11/2004; 14(11):2046-52. · 4.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was to evaluate safety and feasibility of dobutamine cardiovascular magnetic resonance (CMR) in patients with proven or suspected coronary artery disease. Dobutamine CMR was evaluated retrospectively in 400 consecutive patients with suspicion of myocardial ischemia. Dobutamine was infused using an incremental protocol up to 40 microg/kg body weight per minute. All anti-anginal medication was stopped 4 days before the CMR study and infusion time of dobutamine was 6 min per stage. Hemodynamic data, CMR findings and side effects were reported. Patients with contraindications to CMR (metallic implants and claustrophobia) were excluded from analysis. Dobutamine CMR was successfully performed in 355 (89%) patients. Forty-five (11%) patients could not be investigated adequately because of non-cardiac side effects in 29 (7%) and cardiac side effects in 16 (4%) patients. Hypotension (1.5%) and arrhythmias (1%) were the most frequent cardiac side effects. One patient developed a severe complication (ventricular fibrillation) at the end of the study. There were no myocardial infarctions or fatal complications of the stress test. The most frequent non-cardiac side effects were nausea, vomiting and claustrophobia. Age >70 years, prior myocardial infarction and rest wall motion abnormalities showed no significant differences with side effects (P>0.05). Dobutamine CMR is safe and feasible in patients with suspicion of myocardial ischemia.
European Radiology 10/2004; 14(10):1823-8. · 4.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A wide variety of imaging modalities is available for the diagnosis of ischemic coronary artery disease (CAD). Myocardial hypo-perfusion is one of the first steps in the ischemic cascade and can be detected before clinical symptoms, ECG alterations or wall motion abnormalities occur. Currently, nuclear medicine techniques (scintigraphy) such as single-photon emission computed tomography using Thalium-201 or TC-99 m sestamibi are most frequently used for the imaging of myocardial perfusion. Positron emission tomography (PET) is the reference standard for myocardial perfusion imaging. These techniques attain a sensitivity and specificity for the detection of myocardial ischemia of, respectively, 83–95 and 53–95%. However, PET is not widely available, which makes it relatively inaccessible. Other disadvantages of myocardial perfusion imaging scintigraphy are: high costs, long-time commitment, radiation exposure, specificity depending on quality control of laboratory and trained readers and low specificity in presence of left bundle branch block. As a result of the fast hardware and software development magnetic resonance imaging (MRI) has become a promising new technique for perfusion imaging. This paper will give an introduction to myocardial perfusion MRI for the detection of ischemic heart disease followed by an overview of the post-processing procedures.