Coronary Artery Disease: Stillman AE

Oudkerk M, Stillman AE, Halliburton SS, Kalender WA, Möhlenkamp S, McCollough CH, Vliegenthart R, Shaw LJ, Stanford W, Taylor AJ, van Ooijen PM, Wexler L, Raggi P, Anonymous00008, Anonymous00009. · Department of Radiology, Groningen University Hospital, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. · Eur Radiol. · Pubmed #18651153 No free full text.

Abstract: Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multidetector CT is discussed.

Schoenhagen P, Stillman AE, Garcia MJ, Halliburton SS, Tuzcu EM, Nissen SE, Modic MT, Lytle BW, Topol EJ, White RD. · No affiliation provided · Am Heart J. · Pubmed #16644309 No free full text.

Abstract: Modern multidetector computed tomography systems are capable of a comprehensive assessment of the cardiovascular system, including noninvasive assessment of coronary anatomy. Multidetector computed tomography is expected to advance the role of noninvasive imaging for coronary artery disease, but clinical experience is still limited. Clinical guidelines are necessary to standardize scanner technology and appropriate clinical applications for coronary computed tomographic angiography. Further evaluation of this evolving technology will benefit from cooperation between different medical specialties, imaging scientists, and manufacturers of multidetector computed tomography systems, supporting multidisciplinary teams focused on the diagnosis and treatment of early and advanced stages of coronary artery disease. This cooperation will provide the necessary education, training, and guidelines for physicians and technologists assuring standard of care for their patients.

Raggi P, Khan A, Arepali C, Stillman AE. · Emory University School of Medicine, 1365 Clifton Road, NE, AT-504, Atlanta, GA 30322, USA. · Curr Atheroscler Rep. · Pubmed #18706286 No free full text.

Abstract: It has become commonplace to try to gear the intensity of preventive measures to the degree of risk. It is, however, problematic to merely use traditional risk factors to gauge risk in the individual patient because the tools currently in use are based on population estimates and they may not directly apply to the individual being assessed. Indeed, it is not unusual for patients at low to intermediate risk to suffer unexpected events, whereas some high-risk patients appear unusually healthy. Imaging for atherosclerosis may offer an alternative to this approach. Often, there is a large discrepancy between the burden of atherosclerosis estimated with coronary artery calcium or intima-media thickness and the risk of future cardiovascular events estimated with the Framingham risk score. This may justify some of the clinical discrepancy. Here, we review the current evidence surrounding the use of coronary artery calcium for risk prediction.

Oudkerk M, Stillman AE, Halliburton SS, Kalender WA, Möhlenkamp S, McCollough CH, Vliegenthart R, Shaw LJ, Stanford W, Taylor AJ, van Ooijen PM, Wexler L, Raggi P. · Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. · Int J Cardiovasc Imaging. · Pubmed #18504647 links to  free full text

Abstract: Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multi-detector CT is discussed.

Weinreb JC, Larson PA, Woodard PK, Stanford W, Rubin GD, Stillman AE, Bluemke DA, Duerinckx AJ, Dunnick NR, Smith GG. · Yale University School of Medicine, New Haven, Connecticut, USA. <> · J Am Coll Radiol. · Pubmed #17411862 No free full text.

Abstract: Coronary artery disease and other acquired and congenital cardiac diseases are major medical and socio-economic problems. Historically, imaging has had a critical role in the diagnosis and evaluation of acquired and congenital cardiac disease. Advances in computed tomography (CT), with multidetector CT and electron beam CT technology, and magnetic resonance (MR) imaging, now make it possible to noninvasively image the coronary arteries, cardiac chambers, valves, myocardium, and pericardium and assess cardiac function, and CT and MR imaging are becoming increasingly important in the evaluation of cardiac disease. Radiologists, because of their extensive experience in CT and MR imaging, have an important role in imaging cardiac patients using these modalities. This clinical statement of the ACR discusses various technical and patient safety issues related to cardiac CT and MR imaging, and it suggests appropriate qualifications for radiologists until such time as ACR practice guidelines for the performance of cardiac CT and cardiac MR imaging are written and approved through the usual ACR process. It stresses that the interpreting physician is responsible for examining not only the cardiac structures of interest but also all the visualized noncardiac structures and must report any clinically relevant abnormalities of these adjacent structures.

Sirineni GK, Stillman AE. · Division of Cardiothoracic Imaging, Department of Radiology, Emory University School of Medicine, 1364 Clifton Rd NE, Atlanta, GA 30322, USA. · J Thorac Imaging. · Pubmed #17325582 No free full text.

Abstract: Methods of noninvasive evaluation of coronary artery disease-including multidetector row computed tomography, electron beam computed tomography, magnetic resonance imaging, and nuclear studies (single photon emission computed tomography, positron emission tomography)-are reviewed.

Schoenhagen P, Stillman AE, Halliburton SS, Kuzmiak SA, Painter T, White RD. · Department of Radiology, Center for Integrated Non-Invasive Cardiovascular Imaging, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. · Int J Cardiovasc Imaging. · Pubmed #15915941 No free full text.

Abstract: Selective coronary angiography introduced clinical coronary imaging in the late 1950s. The angiographic identification of high-grade coronary lesions in patients with acute and chronic symptomatic coronary artery disease (CAD) led to the development of surgical and percutaneous coronary revascularization. However, the fact that CAD remains the major cause of death in North America and Europe demonstrates the need for novel, complementary diagnostic strategies. These are driven by the need to characterize both increasingly advanced disease stages but also early, asymptomatic disease development. Complex revascularization techniques for patients with advanced disease stages will initiate a growing demand for 3-dimensional coronary imaging and integration of imaging modalities with new mechanical therapeutic devices. An emerging focus is atherosclerosis imaging with the goal to identify subclinical disease stages as the basis for pharmacological intervention aimed at disease stabilization or reversal. Non-invasive coronary imaging with coronary multidetector computed tomographic angiography (MDCTA) allows both assessment of luminal stenosis and subclinical disease of the arterial wall. Its complementary role in the assessment of early and advanced stages of CAD is increasingly recognized.

Schoenhagen P, Stillman AE, Halliburton SS, White RD. · Center for Integrated Non-Invasive Cardiovascular Imaging, Department of Diagnostic Radiology, The Cleveland Clinic Foundation, OH 44195, USA. · Cleve Clin J Med. · Pubmed #15757168 links to  free full text

Abstract: Computed tomography (CT) has become a standard test for many cardiovascular conditions (eg, aortic dissection and pulmonary embolism), and it has great potential in assessing other common diseases, including coronary artery disease. We review the principles of CT and its uses in cardiovascular medicine.

Schoenhagen P, Halliburton SS, Stillman AE, Kuzmiak SA, Nissen SE, Tuzcu EM, White RD. · Department of Radiology, Cleveland Clinic Foundation, Desk Hb 6, 9500 Euclid Ave, Cleveland, OH 44195, USA. · Radiology. · Pubmed #15220490 links to  free full text

Abstract: While invasive imaging techniques, especially selective conventional coronary angiography, will remain vital to planning and guiding catheter-based and surgical treatment of significantly stenotic coronary lesions, the comprehensive and serial assessment of asymptomatic or minimally symptomatic stages of coronary artery disease (CAD) for preventive purposes will eventually need to rely on noninvasive imaging techniques. Cardiovascular imaging with tomographic modalities, including computed tomography (CT) and magnetic resonance imaging, has great potential for providing valuable information. This review article will describe the current and future role of cardiac CT, and in particular that of multi-detector row CT, for imaging of atherosclerotic and other pathologic changes of the coronary arteries. It will describe how tomographic coronary imaging may eventually supplement traditional angiographic techniques in understanding the patterns of atherosclerotic CAD development.

Halliburton SS, Stillman AE, White RD. · Department of Diagnostic Radiology, The Cleveland Clinic Foundation, OH 44195, USA. · Cleve Clin J Med. · Pubmed #12086233 links to  free full text

This publication has no abstract.

Bexell D, Setser RM, Schoenhagen P, Lieber ML, Brener SJ, Ivanc TB, Balazs EM, O Donnell TP, Stillman AE, Arheden H, Wagner GS, White RD. · Departments of Diagnostic Radiology, Duke University Medical Center, Durham, NC. · Open Cardiovasc Med J. · Pubmed #19337359 links to  free full text

Abstract: OBJECTIVES: In patients with chronic ischemic heart disease, the relationship between coronary artery lesion severity and myocardial scarring is unknown.The purpose of this study was to examine the relationship between proximal coronary artery stenosis severity, the amount of coronary collateralization, and myocardial scar extent in the distal distribution of the affected coronary artery based on both quantitative coronary angiography (QCA) and delayed-enhancement magnetic resonance imaging (DE-MRI). METHODS: Thirty-four patients (26 males, 8 females; age range: 35-86 years) with a coronary artery containing a single, proximal stenosis >/=30% by quantitative coronary angiography (QCA) underwent DE-MRI. The relationship between stenosis severity, collateralization, and myocardial scar morphology (area, transmurality and patchiness) was examined using linear mixed-model ANCOVA. RESULTS: There was a statistically significant correlation between stenosis severity and scar extent (r=0.53, p<0.01). Patients with hemodynamically significant stenoses (>/=70%) exhibited significantly greater collateralization (p<0.05) and scar extent (p<0.01) than patients with <70% stenosis. However, scarring was often found in patients with stenoses <70%. Also, greater stenosis severity (93+/-14%) and mean scar extent (41+/-35%) were found in patients with collaterals than in patients without collaterals (diameter stenosis 48+/-10%, p<0.01) (scar extent 19+/-29%, p=0.01). CONCLUSIONS: Using QCA and DE-MRI, we demonstrate a significant relationship between coronary artery stenosis severity and myocardial scar extent, in the absence of a documented history of acute infarction. The relationship likely reflects increasing ischemia leading to scar formation in the range of angiographically significant stenosis. However, in the absence of collateralization, scar was observed without significant stenosis, especially in females.

Stillman AE, Rubin GD, Teague SD, White RD, Woodard PK, Larson PA. · Emory University School of Medicine, Atlanta, Georgia 30322, USA. · J Am Coll Radiol. · Pubmed #18585655 No free full text.

Abstract: With the growing use of electronic medical records, the trend of diagnostic imaging reporting is toward a more structured format. Advantages include improved quality and consistency of the reporting and ease of data mining. The essential elements of a structured report are provided and illustrated for coronary artery computed tomographic angiograms.

Sirineni GK, Raggi P, Shaw LJ, Stillman AE. · Department of Radiology, Emory University School of Medicine, 1365 Clifton Road NE, AT-504, Atlanta, GA 30322, USA. · Int J Cardiovasc Imaging. · Pubmed #17534734 No free full text.

Abstract: Coronary artery calcium (CAC) accumulation, a marker of atherosclerosis burden, differs significantly among patients of different ethnicities. It has been proposed that CAC scores can be used to assess the number of life years lost or gained by an individual with a given amount of coronary artery calcium. Therefore, we sought to develop a method to calculate the coronary age of an individual based on the extent of CAC in this subject compared to that of individuals of the same race, age and sex. We used median CAC scores from previously published data from the Multi-Ethnic Study of Atherosclerosis (MESA) to derive the predicted coronary age of subjects from 4 ethnic groups (White, Black, Hispanic and Chinese) of both sexes. With this method a 50-year-old white man with a CAC score of 40 has a coronary age of a 61-year-old white man; for a black man with a score of 40 the coronary age is 70. This method should allow patients to better understand the prognostic significance of their test results and may ensure a better compliance with preventive regimens.

Carmichael BB, Setser RM, Stillman AE, Lieber ML, Smedira NG, McCarthy PM, Starling RC, Young JB, Weaver JA, Lawrence AG, White RD. · Center for Integrated Non-Invasive Cardiovascular Imaging of the Department of Radiology, Cleveland Clinic Foundation, Desk Hb6, 9500 Euclid Ave, Cleveland, OH 44195, USA. · Radiology. · Pubmed #17114621 links to  free full text

Abstract: PURPOSE: To retrospectively evaluate with dynamic magnetic resonance (MR) imaging the changes in global and regional left ventricular (LV) function after surgical ventricular restoration (SVR) performed in chronic ischemic heart disease patients with large nonaneurysmal or aneurysmal postmyocardial infarction zones. MATERIALS AND METHODS: The study was performed with institutional review board approval, and a waiver of individual informed consent was obtained. The study was HIPAA compliant. Patients (83 men, 22 women; mean age, 61 years +/- 9 [standard deviation]) were evaluated with MR imaging before and after SVR as follows: pre-SVR examination (n = 105; 25 days +/- 39 before SVR; median, 7 days; range, 1-189 days), early post-SVR examination (n = 95, 7 days +/- 3 after SVR), and late post-SVR (n = 35, 313 days +/- 158 after SVR). Cine MR imaging allowed calculation of ejection fraction and rate-corrected velocity of circumferential fiber shortening (Vcf(C)) for global LV functional evaluation, whereas tagged MR imaging (spatial modulation of magnetization with harmonic phase analysis) permitted assessment of regional circumferential strain (E(C)) with coronary distribution. Vcf(C) and E(C) were computed at both LV base- and mid-LV short-axis levels remote from the site of anteroapical SVR. RESULTS: Prior to SVR, LV dilatation and diminished global and regional LV function were observed. At early post-SVR examination, Vcf(C) had improved significantly but E(C) showed a worsening trend overall, although only E(C )of the right coronary artery at the mid-LV level worsened significantly. At late post-SVR examination, Vcf(C) values were improved when compared with pre-SVR values, although E(C) showed no statistically significant improvement. When compared with that at early post-SVR examination, however, E(C) showed significant improvement in two segments: left anterior descending artery and right coronary artery at mid-LV level. CONCLUSION: Although volume-based indexes of global LV function improve significantly after SVR, regional LV function did not improve significantly; there was evidence of continued LV remodeling after SVR.

Setser RM, O'Donnell TP, Smedira NG, Sabik JF, Halliburton SS, Stillman AE, White RD. · Department of Radiology, Section of Cardiovascular Imaging, the Cleveland Clinic Foundation, Cleveland, OH 44195, USA. · Radiology. · Pubmed #16244254 links to  free full text

Abstract: PURPOSE: To evaluate assignment of left ventricular (LV) myocardial segments to coronary arterial territories by using coregistered magnetic resonance (MR) imaging and multi-detector row computed tomography (CT) displays; to assess the accuracy of coregistered displays in determining the distribution of clinically important coronary artery disease (CAD) and regional effect of CAD on LV myocardium in patients with chronic ischemic heart disease (CIHD); and to determine the utility of coregistered displays in optimizing surgical revascularization planning. MATERIALS AND METHODS: This study was HIPAA compliant and was approved by the local Institutional Review Board, with waiver of informed consent. Twenty-six patients (19 men, seven women; age, 56 years +/- 12 [+/- standard deviation]) with CIHD underwent MR imaging assessment of myocardial viability and multi-detector row CT assessment of CAD on the same day. For coregistration, a population-based LV model was fit to each data set separately; models were then registered spatially. For data analysis, correspondence between coregistered displays and the 17-segment LV model for assessment of CIHD was evaluated, accuracy of using coregistered displays to evaluate the extent of CAD and myocardial disease was assessed, and utility of coregistered displays in optimizing surgical revascularization planning was determined. RESULTS: Coronary assignment for coregistered displays and the 17-segment LV model differed in 17% of myocardial segments. For the majority of patients, three segments (midanterolateral [62%], apical lateral [73%], and apical inferior [58%]) were discordant. Segments were supplied by the left anterior descending artery, a diagonal branch, or a ramus intermedius with diagonal distribution in all but one case. Coregistered displays were deemed concordant with selective coronary angiography and alternate myocardial imaging in all cases. Overall, surgical planning was potentially enhanced in 83% of cases because, compared with alternate imaging modalities, coregistered displays were believed to demonstrate the relationship between coronary arteries and underlying myocardial tissue more definitively and efficiently (for patients in whom surgery was performed) or more correctly and comprehensively (for a presumably better-tailored surgery). CONCLUSION: Assessment of CIHD can be improved by using coregistered displays that directly relate the condition of LV myocardium to the anatomy of the coronary arteries in individual patients.

Srichai MB, Grimm RA, Stillman AE, Gillinov AM, Rodriguez LL, Lieber ML, Lara A, Weaver JA, McCarthy PM, White RD. · Department of Radiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA. · Ann Thorac Surg. · Pubmed #15975362 No free full text.

Abstract: BACKGROUND: Mitral regurgitation (MR) is a common complication of ischemic heart disease, and its presence portends adverse outcomes. As the exact mechanisms of ischemic MR are not well defined, we characterized left ventricular global geometry, regional function, and regional myocardial scarring, in addition to mitral valve apparatus geometry, using magnetic resonance imaging (MRI) of ischemic heart disease patients with left ventricular dysfunction and varying degrees of ischemic MR. METHODS: Sixty patients with varying degrees of MR (none, mild, moderate, and severe) determined by echocardiography and referred for MRI assessment of ischemic heart disease were included. Left ventricular geometric, functional, and scar measurements in addition to mitral valve geometric measurements were evaluated. RESULTS: Clinical characteristics found to be significant predictors of degree of MR included severity of coronary artery disease (p < 0.05), completeness of myocardial perfusion (p < 0.005), and average systolic blood pressure (p < 0.05). Mitral systolic tenting area (p < 0.0001) in a statistical model with scarring of the anterior-lateral region (p < 0.05) proved to be the most powerful predictor of MR severity (r2 = 0.31). Mitral annular dilatation in the anterior-posterior direction (p < 0.0001) and diminished LV systolic function (p < 0.005) were important determinants of mitral systolic tenting area (r2 = 0.57). CONCLUSIONS: Mitral tenting in combination with regional left ventricular myocardial scarring are important mechanisms to the development of ischemic MR. Surgical annuloplasty addresses mitral tenting, but has little impact on the effect of regional scarring. Moderate-to-severe ischemic MR develops in patients with regional scarring of the anterior-lateral and inferior-posterior regions, and new surgical developments should take this into account.

Halliburton SS, Stillman AE, Lieber M, Kasper JM, Kuzmiak SA, White RD. · Section of Cardiovascular Imaging, Division of Radiology/Hb6, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA. · AJR Am J Roentgenol. · Pubmed #15671391 links to  free full text

Abstract: OBJECTIVE: The potential clinical impact of variability in the measurement of coronary artery calcification with sequential MDCT was evaluated using Agatston, volume, and mass scoring algorithms. SUBJECTS AND METHODS: Fifty-six patients were imaged twice using an identical prospectively ECG-triggered sequential scanning protocol. The Agatston, volume, and mass scores were computed by two observers independently. In addition, a patient's total Agatston score was referenced to an age- and sex-stratified database to determine a percentile ranking. Interscan, interobserver, and intraobserver variability and the resultant impact on patients' risk stratifications were assessed. RESULTS: Significant interscan differences were found for all mean coronary calcium scores (Wilcoxson's signed rank test, p <0.0001). Although the median percentage of interscan variability was low for all scoring methods, the interquartile range was wide, indicating significant variability in the data. Median scores (lower quartile-upper quartile) for observers 1 and 2, respectively, were as follows: Agatston, 5% (0-79%) and 6% (0-83%); volume, 12% (0-51%) and 12% (0-57%); and mass, 14% (0-57%) and 14% (0-58%). Interobserver and intraobserver differences between mean calcium scores were not significant, and consequently, lower interobserver and intraobserver variabilities (narrow interquartile ranges of 0-5%) were observed for all scores. Despite significant interscan differences in calcium scores, the percentile ranking assigned to the two scans differed in only 13% of patients. Interobserver differences resulted in a change in the percentile ranking in 7-9% of patients, whereas intraobserver differences caused a change in only 5% of patients. CONCLUSION: The accuracy of sequential MDCT for coronary calcium quantification is sufficient in most cases for stratification of patient risk.

Folsom AR, Evans GW, Carr JJ, Stillman AE, Anonymous00373. · Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, MN 55454-1015, USA. · Angiology. · Pubmed #15547647 No free full text.

Abstract: Coronary artery calcification assessed by computed tomography is an emerging marker of coronary atherosclerosis. The authors examined the association of coronary calcium scores with traditional and nontraditional cardiovascular risk factors. In 1999-2000, they measured coronary artery calcium in 360 participants free of known coronary artery disease who had participated in 2 centers of the Atherosclerosis Risk in Communities (ARIC) Study. They related coronary calcium scores to risk factors measured in 1987-1989. Most traditional risk factors were associated with the coronary calcium score. For example, the multivariately adjusted odds ratio for an elevated score (> or = 100 versus < 100) was 3.5-fold greater per 10 years of age, 3.2-fold greater in men than in women, 3.1-fold greater with diabetes (statistically nonsignificant), and 1.4- to 1.7-fold greater per standard deviation greater increments of plasma cholesterol and pack-years of cigarettes smoked. Carotid artery intima-media thickness also was positively associated with coronary calcification. In contrast, a wide variety of hemostatic and inflammatory markers and serum chemistry values were unrelated to calcium scores. These findings reaffirmed the established role of traditional risk factors in the etiology of coronary artery disease, as assessed by computed tomography, but did not identify any important nontraditional risk factors.

Sturm B, Powell KA, Stillman AE, White RD. · Department of Biomedical Engineering, Lerner Research Institute, Cleveland, OH 44195, USA. · Int J Cardiovasc Imaging. · Pubmed #14598896 No free full text.

Abstract: A method for the registration of 3D cardiac CT angiography (CTA) and magnetic resonance (MR) data sets based on their myocardial epicardial surfaces is introduced. The approach relies on temporally registered data sets obtained based on the electrocardiogram recorded during the CTA acquisition and the timing characteristics of the MR acquisition. The myocardial epicardial surfaces were identified in the reformatted CTA and MR data sets using a 3D semi-automated segmentation algorithm. This algorithm was implemented, evaluated on clinical data, and compared to a set of manual outlines during the course of this study. The registration of the CTA and MR data sets was based on the iterative closest point algorithm, which minimizes the distance between the surfaces defined by the epicardial outlines in each data set. The proposed technique was applied to data obtained from 11 patients with coronary artery disease. The CTA data was reformatted based on the registration results and the location of the MR imaging planes. The resulting CTA-MR image pairs were evaluated qualitatively by two experts, who graded the majority of the cases as either excellent or acceptable (11 of 11 cases for one reader, and 9 of 11 for the other). The results were evaluated quantitatively based on the distance between the registered epicardial surfaces. The quantitative measures indicated that the registered surfaces were within two pixels of one another (on average). The registration results were used to generate combined 3D renderings of information extracted from both data sets for visualization purposes.

Schoenhagen P, Tuzcu EM, Stillman AE, Moliterno DJ, Halliburton SS, Kuzmiak SA, Kasper JM, Magyar WA, Lieber ML, Nissen SE, White RD. · Department of Radiology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. · Coron Artery Dis. · Pubmed #12966267 No free full text.

Abstract: BACKGROUND: Non-invasive identification and characterization of mildly stenotic atherosclerotic lesions is an increasingly important focus of coronary imaging. DESIGN: We examined the accuracy of multi (16)-slice computed tomography (MSCT) for imaging of these lesions in comparison with intravascular ultrasound (IVUS). MATERIALS: Mildly stenotic segments of the left coronary artery were identified by coronary angiography and analyzed using IVUS and contrast-enhanced MSCT. Independent reviewers evaluated the accuracy of MSCT for presence, composition and distribution of atherosclerotic plaque and remodeling response in comparison to IVUS using receiver operating characteristic (ROC) data analysis. RESULTS: Of 46 segments in 14 patients, diagnostic characterization by MSCT was possible in 37 (80.4%) segments. In these segments the accuracy of MSCT for identifying plaque presence, calcification, distribution and positive remodeling was consistently greater than 0.90 (reader 1) and 0.87 (reader 2). CONCLUSION: State-of-the-art MSCT can accurately identify mildly stenotic coronary atherosclerosis and provide an assessment of morphology and remodeling response.

Jerosch-Herold M, Wilke N, Wang Y, Gong GR, Mansoor AM, Huang H, Gurchumelidze S, Stillman AE. · Department of Radiology, University of Minnesota, Minneapolis 55455, USA. · Int J Card Imaging. · Pubmed #10768740 No free full text.

Abstract: A direct comparison of extracellular and intravascular contrast agents for the assessment of myocardial perfusion was carried out in a porcine model (N = 5) with a flow-limiting occluder on the left anterior descending coronary artery. Rapid imaging during the first pass of an extracellular or intravascular contrast agent with a saturation-recovery-prepared TurboFLASH sequence showed comparable peak contrast-to-noise enhancements in myocardial tissue regions with flows averaging 1.1 +/- 0.2 at baseline to 4.8 +/- 0.6 ml/min/g during hyperemia. The coefficient of variation between the MR estimates of blood flow with Gadomer-17 and the microsphere blood flow measurements was 11 +/- 11%, while the corresponding co-efficient of variation for blood flow estimates with the extracellular CA was 23 +/- 11%. Blood volume differences between rest and hyperemia observed with the intravascular tracer were significant (Vvasc(rest) = 0.078 +/- 0.013 ml/g, versus Vvasc(hyperemia) = 0.102 +/- 0.019 ml/g; p < 0.05). The effects of water exchange were minimized through the choice of pulse sequence parameters to provide blood volume estimates consistent with the changes expected between rest and hyperemia. This study represents the first application of multiple indicators in first pass imaging studies for the assessment of myocardial perfusion. The use of an intravascular instead of an extracellular contrast agent allows a reduction of the degrees of freedom for modeling tissue residue curves and results in improved accuracy of blood flow estimates.