Acute versus Chronic Myocardial Infarction: Diagnostic Accuracy of Quantitative Native T1 and T2 Mapping versus Assessment of Edema on Standard T2-weighted Cardiovascular MR Images for Differentiation.

Purpose To analyze the diagnostic accuracy of native T1 and T2 mapping compared with visual and quantitative assessment of edema on T2-weighted cardiac magnetic resonance (MR) images to differentiate between acute and chronic myocardial infarction. Materials and Methods This study had institutional ethics committee approval. Written informed consent was obtained from 67 consecutive patients (57 years ± 12; 78% men) with a first acute myocardial infarction, who were prospectively enrolled between April 2011 and June 2015. Four serial 1.5-T MR imaging examinations were performed at 8 days ± 5, 7 weeks ± 2, 3 months ± 0.5, and 6 months ± 1.4 after infarction and included T2-weighted, native T1/T2 mapping, and late gadolinium enhancement MR imaging. Complete follow-up data were obtained in 42 patients. Regional native T1/T2 relaxation time, T2-weighted ratio, and extracellular volume were serially measured in infarcted and remote myocardium. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of the MR imaging parameters for discriminating between acute and chronic myocardial infarction. Results Native T1 of infarcted myocardium decreased from 1286 msec ± 99 at baseline to 1077 msec ± 50 at 6 months (P < .0001), whereas T2 decreased from 84 msec ± 10 to 58 msec ± 4 (P < .0001). The T2-weighted ratio decreased from 4.1 ± 1.0 to 2.4 ± 0.6 (P < .0001). Of all the MR imaging parameters obtained, native T1 and T2 yielded the best areas under the ROC curve (AUCs) of 0.975 and 0.979, respectively, for differentiating between acute and chronic myocardial infarction. Visual analysis of the presence of edema at standard T2-weighted cardiac MR imaging resulted in an inferior AUC of 0.863 (P < .01). Conclusion Native T1 and T2 of infarcted myocardium are excellent discriminators between acute and chronic myocardial infarction and are superior to all other MR imaging parameters. Online supplemental material is available for this article.

Assessment of Left Ventricular Enlargement at Multidetector Computed Tomography.

PURPOSE: Because left ventricular (LV) enlargement (LVE) is indicative of an array of cardiac pathologies, including cardiomyopathic, ischemic, and valvular heart diseases, it is important to recognize it early in the course of these diseases. The recognition of LVE on nongated contrast-enhanced computed tomography (CT) scans should be facilitated by the availability of a dimensional index. To our knowledge, no CT index of LVE has been proposed. Therefore, the study aimed to define whether the maximum LV diameter (LVd) measured on nongated multidetector computed tomography can identify LVE when referencing echocardiography as the diagnostic standard. MATERIALS AND METHODS: The patient population consisted of 438 consecutive patients who had a contrast-enhanced, nongated 16- or 64-detector CT of the chest for evaluation of pulmonary embolism or aortic dissection between January 2006 and March 2008. One hundred fifty-five patients in this group also had an echocardiogram within 2 months of the CT study. The maximum LV cavity size, septal to lateral wall dimension, was measured perpendicularly to the long axis of the left ventricle on the axial CT scans by 2 observers blinded to the echocardiography data.An receiver operating characteristic analysis was performed to identify a highly specific cutoff for the diagnosis of LVE on CT, using echocardiogram as the standard of reference. Interobserver agreement was assessed using Bland-Altman analysis. RESULTS: A total of 84 females and 71 males were evaluated (female to male ratio of 1.09). The mean age for the 155 patients was 58 years. Six percent of these patients had a diagnosis of LVE on 2-dimensional echocardiography. The mean (SEM) LV internal diameter at nongated multidetector computed tomography between the group with normal LV and the group with LVE by echocardiography was 4.4 (0.7) cm for the normal LV and 5.9 (1.2) cm for the dilated LVs (P < 0.0001). With the use of threshold value of LVd of 5.6 cm, a sensitivity of 78%, specificity of 100%, positive likelihood ratio of 113.5, and negative likelihood ratio of 0.22 were calculated. The LVd measurements had an excellent agreement between observers on the Bland-Altman analysis. CONCLUSIONS: Left ventricular enlargement can be reliably identified on nongated contrast-enhanced multidetector CT when the maximum luminal diameter of the LV is greater than 5.6 cm. Nongated contrast-enhanced CT scan can be used to recognize LVE.

Cardiac radiology: centenary review.

During the past century, cardiac imaging technologies have revolutionized the diagnosis and treatment of acquired and congenital heart disease. Many important contributions to the field of cardiac imaging were initially reported in Radiology. The field developed from the early stages of cardiac imaging, including the use of coronary x-ray angiography and roentgen kymography, to nowadays the widely used echocardiographic, nuclear medicine, cardiac computed tomographic (CT), and magnetic resonance (MR) applications. It is surprising how many of these techniques were not recognized for their potential during their early inception. Some techniques were described in the literature but required many years to enter the clinical arena and presently continue to expand in terms of clinical application. The application of various CT and MR contrast agents for the diagnosis of myocardial ischemia is a case in point, as the utility of contrast agents continues to expand the noninvasive characterization of myocardium. The history of cardiac imaging has included a continuous process of advances in our understanding of the anatomy and physiology of the cardiovascular system, along with advances in imaging technology that continue to the present day.

Cardiovascular MR imaging after surgical correction of tetralogy of Fallot: approach based on understanding of surgical procedures.

Tetralogy of Fallot (TOF) is one of the most common congenital heart diseases for which patients are referred for postoperative magnetic resonance (MR) imaging evaluation. The most common surgical procedures for TOF repair include infundibulectomy, transannular pulmonary artery patch repair, and right ventricle-pulmonary artery conduit placement. In the past few decades, surgery has proved successful, but most patients require repeat imaging throughout their lives. MR imaging is now frequently used for morphologic and functional evaluation after TOF repair. The most common late postoperative sequelae and residual lesions include right ventricular outflow tract aneurysm and dyskinesis, conduit failure, pulmonary regurgitation, tricuspid regurgitation, right ventricular failure, residual main and branch pulmonary artery stenosis, branch pulmonary artery aneurysm, left pulmonary artery kinking, and residual or recurrent ventricular septal defect. The imaging approach for the evaluation of patients with repaired TOF should be guided by the surgical procedure used and the complications that are expected. Knowledge of the most common postoperative problems and their cardiovascular MR imaging appearances is essential for good radiology practice in this clinical setting.

CMR assessment of right ventricular function in patients with combined pulmonary stenosis and insufficiency after correction of tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF) is one of the most common types of congenital heart disease and requires prompt surgical correction. Post-correction pulmonary insufficiency (PI) often ensues in adulthood. At times, the PI is accompanied by residual pulmonary stenosis (PS). Little is known regarding right ventricular (RV) function in the setting of combined PS and PI. PURPOSE: To compare cardiac magnetic resonance (CMR) parameters for the assessment of RV function between patients with combined pulmonary stenosis and pulmonary insufficiency (PSPI) and isolated PI following surgical repair of TOF. MATERIAL AND METHODS: Retrospective review of patients with comparable corrected TOF and similar PI was performed. Seventeen patients (median age, 24 years; range, 10-52 years) had combined PSPI and 30 patients (median age, 30 years; range, 6-70 years) had isolated PI. Cine magnetic resonance (MR) images (Philips Medical Systems, Best, The Netherlands) in the short-axis plane were used to calculate end-systolic, end-diastolic, and stroke volumes (RVESV, RVEDV, RVSV) and to measure RV wall thickness. Velocity-encoded cine MR images were used to measure pulmonary regurgitation fraction (PRF) by calculating the ratio of backward flow and total forward flow, obtained from the main pulmonary flow analysis. Peak pressure gradient across the pulmonary valve was obtained from spectral Doppler echocardiography. RESULTS: RVEF was 51 ± 8% in the PSPI patients and 39 ± 11%, in the patients with isolated PI (P = 0.001). Additionally, RV wall thickness was 5.2 ± 0.8 mm in the PSPI patients compared to 2.6 ± 0.9 mm in the isolated PI patients (P = 0.001). RVESVi and RVEDVi were significantly lower (P < 0.05) in patients with combined PSPI (60 ± 21 mL/m(2), 121 ± 35 mL/m(2), respectively) compared to the patients with isolated PI (95 ± 48 mL/m(2), 152 ± 61 mL/m(2), respectively). CONCLUSION: RV function is preserved in patients with PSPI when compared to patients with PI following surgical repair of TOF.

Impaired regional left ventricular strain after repair of tetralogy of Fallot.

PURPOSE: To test the potential of magnetic resonance imaging (MRI) in early detection of left ventricular (LV) dysfunction in patients with pulmonary regurgitation and normal LV ejection fraction after repair of tetralogy of Fallot. MATERIALS AND METHODS: Patients (n = 18) with repaired tetralogy of Fallot and pulmonary regurgitation were prospectively recruited. Healthy volunteers (n = 10) were used as control. Tagging MR images were acquired at the base, mid, and apical LV levels for assessing segmental rotation and circumferential strain. Cine MR images and velocity-encoded MR images were also acquired for assessment of biventricular volumes and biventricular function and pulmonary regurgitant fraction, respectively. Mean values were compared between groups using unpaired Student's t-test. RESULTS: Patients presented with preserved global LV function (LVEF of 59 ± 5%). A significant decrease in LV peak circumferential strain was seen in patients compared with normal volunteers at the basilar (-15.6 ± 4.5% vs. -17.6 ± 4.4%; P < 0.01) and apical (-14.4± 6.1% vs. -17.3± 5.1%, P < 0.01) slices. LV peak rotation was also delayed in patients compared with volunteers at the basilar (6.1 ± 2.6° vs. 4.2 ± 0.6°; P < 0.01) and mid (8.0 ± 1.7° vs. 4.9 ± 1.0°; P < 0.01) slices. CONCLUSION: MRI can detect early regional LV dysfunction in patients with preserved LVEF after repair of tetralogy of Fallot. MR may be a useful technique for guiding clinical decisions in these patients in order to prevent future global LV deterioration.

Delayed contrast enhancement on MR images of myocardium: past, present, future.

Differential enhancement of myocardial infarction was first recognized on computed tomographic (CT) images obtained with iodinated contrast material in the late 1970s. Gadolinium enhancement of myocardial infarction was initially reported for T1-weighted magnetic resonance (MR) imaging in 1984. The introduction of an inversion-recovery gradient-echo MR sequence for accentuation of the contrast between normal and necrotic myocardium was the impetus for widespread clinical use for demonstrating the extent of myocardial infarction. This sequence has been called delayed-enhancement MR and MR viability imaging. The physiologic basis for differential enhancement of myocardial necrosis is the greater distribution volume of injured myocardium compared with that of normal myocardium. It is now recognized that delayed enhancement occurs in both acute and chronic (scar) infarctions and in an array of other myocardial processes that cause myocardial necrosis, infiltration, or fibrosis. These include myocarditis, hypertrophic cardiomyopathy, amyloidosis, sarcoidosis, and other myocardial conditions. In several of these diseases, the presence and extent of delayed enhancement has prognostic implications. Future applications of delayed enhancement with development of MR imaging and CT techniques will be discussed.

Tetralogy of Fallot: impact of the excursion of the interventricular septum on left ventricular systolic function and fibrosis after surgical repair.

PURPOSE: To quantify the excursion of interventricular septum (IVS) in patients after repair of tetralogy of Fallot (TOF), a marker of interventricular interaction, and assess its association with left ventricular (LV) ejection fraction, LV septal wall thickening, and LV fibrosis. MATERIALS AND METHODS: The HIPAA-compliant protocol received institutional board review approval. IVS excursion was measured at cardiovascular magnetic resonance (MR) imaging in 82 patients after repair of TOF and in 10 healthy volunteers. IVS excursion was correlated with LV ejection fraction, LV septal wall thickening, and LV delayed gadolinium enhancement. Independent predictors of reduced LV ejection fraction were identified, including significant univariable predictors with use of a multivariable logistic regression model. RESULTS: IVS excursion was greater in patients than in healthy volunteers (5.3 mm ± 3.1 vs 1.2 mm ± 0.4, P < .01). Patients (n = 68) with abnormal excursion of the IVS had reduced LV ejection fraction (57% ± 7 vs 61% ± 4, P < .01) and reduced LV septal wall thickening (24% ± 10 vs 29% ± 5, P = .01) compared with patients with normal IVS excursion. Maximal IVS excursion (odds ratio = 1.27 per millimeter, P = .03) and right ventricular (RV) ejection fraction (odds ratio = 0.92 per percentage, P = .031) were independent predictors of reduced LV ejection fraction (<55%). Among the 44 patients with delayed enhancement images, those with abnormal excursion of the IVS had higher LV delayed enhancement scores (median, 1.5 [interquartile range, 0-2] vs 0 [interquartile range, 0-0]; P < .01] than patients with normal IVS excursion. Notably, in all but one patient the delayed enhancement was located at the RV-LV hinge points. CONCLUSION: Abnormal IVS excursion after repair of TOF is associated with reduced global and septal LV systolic function and LV fibrosis at the RV-LV hinge points, suggesting a mechanism of adverse interventricular interaction.

Cardiovascular MRI for the assessment of heart failure: focus on clinical management and prognosis.

Cardiovascular MR (CMR) has an emerging role in the noninvasive diagnostic assessment of heart failure (HF). Different imaging sequences allow for a detailed assessment of cardiac morphology, function, myocardial perfusion, tissue characterization, and blood flow measurement. This article reviews the key applications of CMR in HF, with special focus on how CMR may influence the diagnostic and therapeutic approach of HF patients.

Diagnostic value of the flow profile in the distal descending aorta by phase-contrast magnetic resonance for predicting severe coarctation of the aorta.

PURPOSE: To compare aortic flow profiles at the level of the proximal descending (PDAo) and distal descending aorta (DDAo) in patients investigated for coarctation of the aorta (CoA), and compare their respective diagnostic value for predicting severe CoA. Diastolic flow decay in the PDAo predicts severe CoA, but flow measurements at this level are limited by flow turbulence, aliasing, and stent-related artifacts. MATERIALS AND METHODS: We studied 49 patients evaluated for CoA with phase contrast magnetic resonance imaging (PC-MRI). Parameters of diastolic flow decay in the PDAo and DDAo were compared. Their respective diagnostic value was compared with the standard reference of transcatheter peak gradient ≥20 mmHg. RESULTS: Flow measurement in the PDAo required repeated acquisition with adjustment of encoding velocity or location of the imaging plane in 69% of patients; measurement in the DDAo was achieved in single acquisition in all cases. Parameters of diastolic flow decay in the PDAo and DDAo, including rate-corrected (RC) deceleration time and RC flow deceleration yielded a good correlation (r = 0.78; P < 0.01, and r = 0.92; P < 0.01), and a similar diagnostic value for predicting severe CoA. The highest diagnostic accuracy was achieved by RC deceleration time at DDAo (sensitivity 85%, specificity 85%). CONCLUSION: Characterization of aortic flow profiles at the DDAo offers a quick and reliable noninvasive means of assessing hemodynamically significant CoA.

Bicuspid aortic valve: four-dimensional MR evaluation of ascending aortic systolic flow patterns.

PURPOSE: To use time-resolved three-dimensional phase-contrast magnetic resonance (MR) imaging, also called four-dimensional flow MR imaging, to evaluate systolic blood flow patterns in the ascending aorta that may predispose patients with a bicuspid aortic valve (BAV) to aneurysm. MATERIALS AND METHODS: The HIPAA-compliant protocol received institutional review board approval, and informed consent was obtained. Four-dimensional flow MR imaging was used to assess blood flow in the thoracic aorta of 53 individuals: 20 patients with a BAV, 25 patients with a tricuspid aortic valve (TAV), and eight healthy volunteers. The Fisher exact test was used to evaluate the significance of flow pattern differences. RESULTS: Nested helical flow was seen at peak systole in the ascending aorta of 15 of 20 patients with a BAV but in none of the healthy volunteers or patients with a TAV. This flow pattern was seen both in patients with a BAV with a dilated ascending aorta (n = 6) and in those with a normal ascending aorta (n = 9), was seen in the absence of aortic stenosis (n = 5), and was associated with eccentric systolic flow jets in all cases. Fusion of right and left leaflets gave rise to right-handed helical flow and right-anterior flow jets (n = 11), whereas right and noncoronary fusion gave rise to left-handed helical flow with left-posterior flow jets (n = 4). CONCLUSION: Four-dimensional flow MR imaging showed abnormal helical systolic flow in the ascending aorta of patients with a BAV, including those without aneurysm or aortic stenosis. Identification and characterization of eccentric flow jets in these patients may help identify those at risk for development of ascending aortic aneurysm.

Clinical evaluation of aortic coarctation with 4D flow MR imaging.

PURPOSE: To show that 4D Flow is a clinically viable tool for evaluation of collateral blood flow and demonstration of distorted blood flow patterns in patients with treated and untreated aortic coarctation. MATERIALS AND METHODS: Time-resolved, 3D phase contrast magnetic resonance imaging (MRI) (4D Flow) was used to assess blood flow in the thoracic aorta of 34 individuals: 26 patients with coarctation (22 after surgery or stent placement) and eight healthy volunteers. RESULTS: Direct comparison of blood flow calculated with 2D and 4D phase contrast data at standard levels for analysis in coarctation patients showed good correlation and agreement (correlation coefficient r = 0.99, limits of agreement = -20% to 20% for collateral blood flow calculations). Abnormal blood flow patterns were demonstrated at peak systole with 4D Flow visualization techniques in the descending thoracic aorta of patients but not volunteers. Marked helical flow was seen in 9 of 13 patients with angulated aortic arch geometries after coarctation repair. Vortical flow was seen in regions of poststenotic dilation. CONCLUSION: 4D Flow is a fast and reliable means of evaluating collateral blood flow in patients with aortic coarctation in order to establish hemodynamic significance. It also can detect distorted blood flow patterns in the descending aorta after coarctation repair.

Society for Cardiovascular Magnetic Resonance guidelines for reporting cardiovascular magnetic resonance examinations.

These reporting guidelines are recommended by the Society for Cardiovascular Magnetic Resonance (SCMR) to provide a framework for healthcare delivery systems to disseminate cardiac and vascular imaging findings related to the performance of cardiovascular magnetic resonance (CMR) examinations.

MR assessment of myocardial perfusion, viability, and function after intramyocardial transfer of VM202, a new plasmid human hepatocyte growth factor in ischemic swine myocardium.

PURPOSE: VM202, a newly constructed plasmid human hepatocyte growth factor, was transferred intramyocardially after infarction for the purpose of evaluating this strategy as a therapeutic approach for protection from left ventricular (LV) remodeling. MATERIALS AND METHODS: The institutional animal care and use committee approved this study. Pigs underwent coronary artery occlusion and reperfusion and served as either control (n = 8) or VM202-treated (n = 8) animals. VM202 was transferred intramyocardially into four infarcted and four periinfarcted sites. Cardiac magnetic resonance (MR) imaging (cine, perfusion, delayed enhancement) was performed in acute (3 days) and chronic (50 days +/- 3 [standard error of the mean]) infarction. Histopathologic findings were used to characterize and quantify neovascularization. The t test was utilized to compare treated and control groups and to assess changes over time. RESULTS: In acute infarction, MR imaging estimates of function, perfusion, and viability showed no difference between the groups. In chronic infarction, however, VM202 increased maximum signal intensity and upslope at first-pass perfusion imaging and reduced infarct size at perfusion and delayed-enhancement imaging. These changes were associated with a decrease in end-diastolic (2.15 mL/kg +/- 0.12 to 1.73 mL/kg +/- 0.10, P < .01) and end-systolic (1.33 mL/kg +/- 0.07 to 0.92 mL/kg +/- 0.08, P < .001) volumes and an increase in ejection fraction (38.2% +/- 1.3 to 47.0% +/- 1.8, P < .001). In contrast, LV function deteriorated further in control animals. Compared with control animals, VM202-treated animals revealed peninsulas and/or islands of viable myocardium in infarcted and periinfarcted regions and greater number of capillaries (218 per square millimeter +/- 19 vs 119 per square millimeter +/- 17, P < .05) and arterioles (21 per square millimeter +/- 4 vs 3 per square millimeter +/- 1, P < .001). CONCLUSION: Intramyocardial transfer of VM202 improved myocardial perfusion, viability, and LV function.

Permanent coronary artery occlusion: cardiovascular MR imaging is platform for percutaneous transendocardial delivery and assessment of gene therapy in canine model.

PURPOSE: To provide evidence that vascular endothelial growth factor (VEGF) genes delivered transendocardially with magnetic resonance (MR) imaging guidance may neovascularize or improve vascular recruitment in occlusive infarction. MATERIALS AND METHODS: All experimental procedures received approval from the institutional committee on animal research. Dogs with permanent coronary artery occlusion were imaged twice (3 days after occlusion for assessment of acute infarction; a mean of 50 days after occlusion +/- 3 [standard error of the mean] for assessment of chronic infarction). A mixture of plasmid VEGF and plasmid LacZ (n = 6, treated animals) or plasmid LacZ and sprodiamide (n = 6, placebo control animals) was delivered to four sites. MR fluoroscopy was used to target and monitor delivery of genes. The effectiveness of this delivery approach was determined by using MR imaging methods to assess perfusion, left ventricular (LV) function, myocardial viability, and infarct resorption. Histologic evaluation of neovascularization was then performed. RESULTS: MR fluoroscopic guidance of injectates was successful in both groups. Treated animals with chronic, but not those with acute, infarction showed the following differences compared with control animals: (a) steeper mean maximum upslope perfusion (200 sec(-1) +/- 32 vs 117 sec(-1) +/- 15, P = .02), (b) higher peak signal intensity (1667 arbitrary units +/- 100 vs 1132 arbitrary units +/- 80, P = .002), (c) increased ejection fraction (from 27.9% +/- 1.2 to 35.3% +/- 1.6, P = .001), (d) smaller infarction size (as a percentage of LV mass) at MR imaging (8.5% +/- 0.9 vs 11.3% +/- 0.9, P = .048) and triphenyltetrazolium chloride staining (9.4% +/- 1.5 vs 12.7% +/- 0.4, P = .05), and (e) higher vascular density (as number of vessels per square millimeter) at the border (430 +/- 117 vs 286 +/- 19, P = .0001) and core (307 +/- 112 vs 108 +/- 17, P = .0001). CONCLUSION: The validity of plasmid VEGF gene delivered with MR fluoroscopic guidance into occlusive infarction was confirmed by neovascularization associated with improved perfusion, LV function, and infarct resorption.

Left ventricular postmyocardial infarction remodeling studied by combining MR-tagging with delayed MR contrast enhancement.

OBJECTIVES: We sought to monitor the evolution of noninfarcted and infarcted myocardium function in the process of left ventricular (LV) remodeling after a reperfused myocardial infarction. MATERIAL AND METHODS: Pigs (n = 8) were subjected to reperfused infarction. Magnetic resonance imaging (MRI) was performed at 3 days and 8 weeks after infarction. Regional circumferential shortening (Ecc) and principal strain L1 in the infarcted, peri-infarcted, and remote myocardium were evaluated by tagged cine MRI combined with matched late enhancement data (Gadolinium-DOTA-enhanced IR-GRE) Global LV function was evaluated by cine MRI. Animals were euthanized after the second imaging session and tissue samples from the different myocardial regions were obtained for histopathologic study. RESULTS: There was a significant deterioration in Ecc between the 3-day and 8-week studies in the peri-infarcted myocardium at apex (-9.9% +/- 4.5% to -6.5 +/- 3.9; P = 0.046) whereas it remained stable for all other regions at all levels. A trend toward improvement in Ecc existed in the infarcted myocardium when infarction transmurality was less than 50% of the LV wall (-7.5% +/- 0.8% to -12.2% +/- 2.9% P = 0.06). Ecc in infarcted myocardium was significantly inferior (P < 0.002) to that in remote and peri-infarcted myocardium at the apical level (2.7% +/- 2.6% vs. -14.4% +/- 3.3% and -9.9% +/- 4.5%, respectively). Global LV function substantially deteriorated after infarction and was associated with a significant LV dilation. CONCLUSION: These results confirm the hypothesis that scarred myocardium imposes additional functional burden to the peri-infarcted myocardium.

MR imaging of ischemic heart disease.

When ischemic heart disease (IHD) is suspected or confirmed, the primary imaging modality is echocardiography. When appropriate, complementary examinations can be performed. These include stress perfusion scintigraphy, cardiac catheterization, coronary angiography, and CT. MR imaging techniques have developed rapidly over the past several years, and MR imaging has the ability to delineate myocardial perfusion, ventricular function, and myocardial viability in a single examination. Although coronary MR angiography is promising, in recent years it has been supplanted as a noninvasive imaging modality by coronary CT angiography. The other capabilities of MR imaging suggest that it will be performed more and more frequently for the assessment of IHD.

Magnetic resonance imaging as a potential gold standard for infarct quantification.

Accurate diagnosis, characterization, and quantification of myocardial infarction (MI) is essential to assess the impact of therapy and to aid in predicting prognosis of patients with ischemic heart disease. Delayed contrast-enhanced magnetic resonance (DE-MR) imaging has the potential of being the gold standard for quantification of MI. It has also been useful in correlating electrocardiography abnormalities with the location and transmurality of infarction. The focus of this review is to address the strengths and limitations of DE-MR imaging in the detection and quantification of MI for clinicians and investigators in the field of electrocardiology. The biological rationale and technical background for detecting MI by DE-MR imaging were reviewed as well as the different approaches for quantification of the DE-MR images, exemplified by patient cases.

Effect of chronic sustained-release dipyridamole on myocardial blood flow and left ventricular function in patients with ischemic cardiomyopathy.

Dipyridamole increases adenosine levels and augments coronary collateralization in patients with coronary ischemia. This pilot study tested whether a 6-month course of sustained-release dipyridamole/aspirin improves coronary flow reserve and left ventricular systolic function in patients with ischemic cardiomyopathy. Six outpatients with coronary artery disease and left ventricular ejection fraction (LVEF) <40% were treated with sustained-release dipyridamole 200 mg/aspirin 25 mg twice daily for 6 months. Myocardial function and perfusion, including coronary sinus flow at rest and during intravenous dipyridamole-induced hyperemia, were measured using velocity-encoded cine magnetic resonance stress perfusion studies at baseline, 3 months, and 6 months. There was no change in heart failure or angina class at 6 months. LVEF increased by 39%+/-64% (31.0%+/-13.3% at baseline vs 38.3%+/-10.7% at 6 months; P=.01), hyperemic coronary sinus flow increased more than 2-fold (219.6+/-121.3 mL/min vs 509.4+/-349.3 mL/min; P=.01), and stress-induced relative myocardial perfusion increased by 35%+/-13% (9.4%+/-3.4% vs 13.9%+/-8.5%; P=.004). Sustained-release dipyridamole improved hyperemic myocardial blood flow and left ventricular systolic function in patients with ischemic cardiomyopathy.

Meeting highlights of the 8th Annual Scientific Sessions of the Society For Cardiovascular Magnetic Resonance, January 21 to 23, 2005.

Parallel tracks for clinical scientists, basic scientists, and pediatric imagers was the novel approach taken for the highly successful 8th Annual Scientific Sessions of the Society for Cardiovascular Magnetic Resonance, held in San Francisco, California, January 21 to 23, 2005. Attendees were immersed in information on the latest scientific advances in cardiovascular magnetic resonance (CMR) from mice to man and technological advances from systems with field strengths from 0.5 T to 11.7 T. State-of-the-art applications were reviewed, spanning a wide range from molecular imaging to predicting outcome with CMR in large patient populations.