Biomedical subjects

W Patricia Ingkanisorn

Publications and source records attributed to W Patricia Ingkanisorn.

8 recordsLinked to original sources

PubMed2006

Prognosis of negative adenosine stress magnetic resonance in patients presenting to an emergency department with chest pain.

OBJECTIVES: This study was designed to determine the diagnostic value of adenosine cardiac magnetic resonance (CMR) in troponin-negative patients with chest pain. BACKGROUND: We hypothesized that adenosine CMR could determine which troponin-negative patients with chest pain in an emergency department have coronary artery disease (CAD) or future adverse cardiac events. METHODS: Adenosine stress CMR was performed on 135 patients who presented to the emergency department with chest pain and had acute myocardial infarction (MI) excluded by troponin-I. The main study outcome was detecting any evidence of significant CAD. Patients were contacted at one year to determine the incidence of significant CAD defined as coronary artery stenosis >50% on angiography, abnormal correlative stress test, new MI, or death. RESULTS: Adenosine perfusion abnormalities had 100% sensitivity and 93% specificity as the single most accurate component of the CMR examination. Both cardiac risk factors and CMR were significant in Kaplan-Meier analysis (log-rank test, p = 0.0006 and p < 0.0001, respectively). However, an abnormal CMR added significant prognostic value in predicting future diagnosis of CAD, MI, or death over clinical risk factors. In receiver operator curve analysis, adenosine CMR was a more accurate predictor than cardiac risk factors (p < 0.002). CONCLUSIONS: In patients with chest pain who had MI excluded by troponin-I and non-diagnostic electrocardiograms, an adenosine CMR examination predicted with high sensitivity and specificity which patients had significant CAD during one-year follow-up. Furthermore, no patients with a normal adenosine CMR study had a subsequent diagnosis of CAD or an adverse outcome.

Adenosine↗

PubMed2006

Quantitative myocardial infarction on delayed enhancement MRI. Part II: Clinical application of an automated feature analysis and combined thresholding infarct sizing algorithm.

PURPOSE: To compare global and regional myocardial infarction (MI) measurements on clinical gadolinium-enhanced magnetic resonance (MR) images using human manual contouring and a computer algorithm previously validated by histopathology, and to study the degree to which visual assessment and human contouring of infarct extent agreed with the computer algorithm. MATERIALS AND METHODS: Infarct size in 20 patients was measured by human manual contouring and with an automated feature analysis and combined thresholding (FACT) computer algorithm. Short-axis slices were divided into myocardial sectors for regional analysis. Extent of infarction was also graded visually by consensus of expert readers and compared to human and computer contouring. RESULTS: Despite good correlations (R = 0.93-0.95) between human contouring and the FACT algorithm, human contouring overestimated infarct size by 3.8% of the left ventricle (23.8% of the MI) area (P < 0.001). Human contouring also overestimated the circumferential extent, transmural extent, and extent of infarction within a sector by 7.1%, 18.2%, and 27.9%, respectively (all P < 0.001). Both consensus reading and human contouring overestimated infarct grades compared with the FACT algorithm (P = 0.002 and P < 0.001). CONCLUSION: Clinically relevant overestimation of MI can occur in visual interpretation and in human manual contouring, particularly with respect to extent of infarction on a regional basis.

Adult↗

PubMed2006

Long-term safety of cardiac magnetic resonance imaging performed in the first few days after bare-metal stent implantation.

PURPOSE: To investigate the long-term safety of cardiac magnetic resonance imaging (CMR) performed one to seven days after coronary artery stent (bare metal) implantation. MATERIALS AND METHODS: We analyzed 119 consecutive patients with acute myocardial infarction (MI) who underwent emergency coronary stent implantation with a bare-metal stent. CMR using a 1.5T scanner was performed on 51 patients (42.9%) at a mean of 2.7+/-3.1 days after stent implantation (CMR+ group), and the remaining 68 patients (57.1%) served as controls (CMR- group). The patients were followed up to six months for major adverse cardiac events. RESULTS: The average stent size was 3.3+/-0.5x18.4+/-6.7 mm, and 86% of the stents were made of 316L stainless steel. There were no significant differences between the CMR+ and CMR- groups in terms of infarct features, angiographic findings, or stent characteristics. Over a mean follow-up of 4.4+/-2.1 months, 12 patients (10.1%) had 16 events (13.4%). Two patients had adverse events after early MRI scan (4.3%), a rate that is lower than the event rate in the patients who did not undergo MRI (16%, P=0.04), and one of the two events was clearly not MRI related. CONCLUSION: CMR on a 1.5T scanner can be safely performed within one to seven days after coronary bare-metal stent implantation and is not associated with an increased risk of adverse clinical cardiac outcomes. In the light of accumulating data, the guidelines by stent manufacturers should be revised.

Aged↗

PubMed2006

Cardiac magnetic resonance appearance of myocarditis caused by high dose IL-2: similarities to community-acquired myocarditis.

The purpose of this study was to describe and compare the cardiac magnetic resonance (CMR) characteristics of myocarditis caused by high dose interleukin-2 (7 patients) with community-acquired myocarditis (14 patients). A total of 21 patients with suspected myocarditis and elevated cardiac enzymes underwent cine CMR followed by delayed enhancement. The mean ejection fraction was mildly decreased in both groups. The location, pattern, and extent of DE were similar in both groups of patients. The CMR similarities between these two populations suggest that cytokine-mediated cytotoxicity may play an important role in community-acquired myocarditis.

Aged↗

PubMed2005

DENSE with SENSE.

Displacement encoding with stimulated echoes (DENSE) with a low encoding strength phase-cycled meta-DENSE readout and a two fold SENSE acceleration (R = 2) is described. This combination reduces total breath-hold times for increased patient comfort during cardiac regional myocardial contractility studies. Images from phantoms, normal volunteers, and a patient are provided to demonstrate the SENSE-DENSE combination of methods. The overall breath-hold time is halved while preserving strain map quality.

Artifacts↗

PubMed2005

Reproducibility and inter-observer variability of dobutamine stress CMR in patients with severe coronary disease: implications for clinical research.

PURPOSE: The purpose of this study was to analyze reproducibility and inter-observer variability of dobutamine stress cardiac magnetic resonance imaging (dobutamine CMR) and its implications on serial studies. METHODS: Nineteen consecutive patients underwent two dobutamine CMR each (median 12 days apart), as part of eligibility criteria for phase I/II stem cell therapy trial. These patients had Canadian Cardiovascular Society Class III/IV angina despite maximal therapy. The two studies were compared for reproducibility of stress response. To assess inter-observer variability, 29 randomly selected dobutamine CMR studies were analyzed by three experienced observers and Kappa values were computed to measure the agreement. RESULTS: Dobutamine CMR studies were completed without any major complications. The left ventricular function, dobutamine and atropine dose, hemodynamic response, symptomatic response and the results of wall motion and perfusion abnormalities were highly reproducible between the two studies (p = .91). Sample size calculations suggested that a clinical trial using dobutamine CMR to detect an endpoint of resolution of two ischemic segments would require a sample size of 20 subjects and to detect an improvement in perfusion of two segments would require a sample size of 8 subjects. Inter-observer variability between individual and consensus interpretation of dobutamine CMR was good to very good (kappa = 0.81 for wall motion and 0.70 for perfusion). CONCLUSION: Dobutamine CMR is a highly reproducible technique with very good inter-observer variability and could be used as a specific endpoint in a relatively small clinical trial.

Adrenergic beta-Agonists↗

PubMed2004

Gadolinium delayed enhancement cardiovascular magnetic resonance correlates with clinical measures of myocardial infarction.

OBJECTIVES: The current study tested the hypothesis that gadolinium delayed enhancement assessment of infarct size correlates with clinical indices of myocardial infarction (MI) in humans. Acute infarct mass by cardiac magnetic resonance (CMR) was compared with peak troponin I, acute and chronic left ventricular (LV) systolic function, and chronic infarct mass in patients imaged after recent acute MI. BACKGROUND: Cardiac magnetic resonance accurately determines myocardial viability in patients with chronic ischemic heart disease but is not well validated for recent MI. METHODS: Patients with first acute MI (n = 33) or chronic MI (n = 10) underwent cine CMR followed by gadolinium delayed enhancement imaging. A follow-up CMR scan was performed on 20 of the 33 acute MI patients and all of the chronic MI patients. RESULTS: In patients with acute percutaneous coronary intervention, acute MI mass correlated with peak troponin I (r = 0.83, p < 0.001, n = 23). In the 20 acute infarct patients with follow-up CMR scans, the acute infarct size correlated well with the follow-up LV ejection fraction (r = 0.86, p < 0.001). The transmural extent of delayed enhancement imaged acutely correlated inversely with wall thickening measured acutely (p < 0.001) and at follow-up (p < 0.001). Although chronic infarct size was reproducible (11 +/- 4% vs. 12 +/- 7%, p = NS), acute infarct size decreased from 16 +/- 12% to 11 +/- 9% (p < 0.003). CONCLUSION: In humans imaged shortly after acute MI, gadolinium delayed enhancement acute CMR infarct size correlates with acute and chronic indices of infarct size but will appear to diminish in size on follow-up.

Aged↗

PubMed2003

Qualitative assessment of regional left ventricular function can predict MRI or radionuclide ejection fraction: an objective alternative to eyeball estimates.

PURPOSE: Assessment of left ventricular function is important in patients with heart disease. We hypothesized that regional wall motion assessed qualitatively by cine magnetic resonance imaging (MRI) can predict the left ventricular ejection fraction (EF). METHODS: The correlations between MRI EF and the American Society of Echocardiography (ASE) score index and a modified ASE score index were established in 117 subjects. The model was tested in the next 86 patients. Interobserver variability was studied in 30 patients. Radionuclide EF was compared in 81 patients. Cine MRI studies were performed on a 1.5 T scanner. RESULTS: From the initial 117 patients, there was a linear correlation between the ASE score index and MRI (r = 0.85), but the relationship improved by including a category of hyperkinetic wall motion (r = 0.90). Using these correlations to predict MRI EF in the next 86 patients, there was a good agreement (r = 0.93 for the ASE score index and r = 0.97 for the modified ASE score index). Correlations between radionuclide EF and the EF predicted by the modified ASE score index or the MRI EF by planimetry were similar (r = 0.91 vs. r = 0.90, respectively). Four observers tested the model and achieved comparable results (r = 0.88 to 0.95). CONCLUSIONS: There is a close relationship between ejection fraction and the ASE score index or modified ASE score index. This correlation can provide an objective prediction of ejection fraction based solely on a qualitative reading of regional wall thickening.

Adolescent↗