Tareq Ibrahim

Assessment of Coronary Flow Reserve: Comparison Between Contrast-Enhanced Magnetic Resonance Imaging and Positron Emission Tomography

OBJECTIVES The study compared flow reserve indices by magnetic resonance imaging (MRI) with quantitative measures of coronary angiography and positron emission tomography (PET). BACKGROUND The noninvasive evaluation of myocardial flow by MRI has recently been introduced. However, a comparison to quantitative flow measurement as assessed by PET has not been reported in patients with coronary artery disease (CAD). METHODS Two groups of healthy volunteers and 25 patients with angiographically documented CAD were examined by MRI and PET at rest and during adenosine stress. Dynamic MRI was performed using a multi-slice ultra-fast hybrid sequence and a rapid gadolinium-diethylenetriaminepenta-acetic acid bolus injection (0.05 mmol/l). Upslope and peak-intensity indices were regionally determined from first-pass signal intensity curves and compared to N-13 ammonia PET flow reserve measurements. RESULTS In healthy volunteers, the upslope analysis showed a stress/rest index of 2.1 plus minus 0.6, which was higher than peak intensity (1.5 plus minus 0.3), but lower than flow reserve by PET (3.9 plus minus 1.1). Localization of coronary artery stenoses (> 75%, MRI < 1.2), based on the upslope index, yielded sensitivity, specificity and diagnostic accuracy of 69%, 89% and 79%, respectively. Upslope index correlated with PET flow reserve (r = 0.70). A reduced coronary flow reserve (PET < 2.0, MRI < 1.3) was detected by the upslope index with sensitivity, specificity and diagnostic accuracy of 86%, 84% and 85%, respectively. CONCLUSIONS Magnetic resonance imaging first-pass perfusion measurements underestimate flow reserve values, but may represent a promising semi-quantitative technique for detection and severity assessment of regional CAD.

Prognostic value of late gadolinium enhancement in cardiovascular magnetic resonance imaging after acute ST-elevation myocardial infarction in comparison with single-photon emission tomography using Tc99m-Sestamibi

BACKGROUND Infarct size is an important predictor of cardiac risk after acute myocardial infarction. The established modality for its assessment is Tc99m-Sestamibi Single-photon emission computed tomography (SPECT). In recent years, data are emerging demonstrating that scar size as assessed by late gadolinium enhancement in cardiovascular magnetic resonance imaging (CMR) as well as the presence of microvascular obstruction (MO) may also provide prognostic information, however, so far no direct comparisons of both modalities have been reported. METHODS We retrospectively analysed patients (n = 281) with acute ST-elevation myocardial infarction and primary angioplasty who underwent Tc99m-Sestamibi-SPECT and CMR on a 1.5 T scanner at a median of 4.3 (IQR: 3.7-5.1) and 4.9 (IQR: 4.1-5.9) days after the acute event, respectively. The primary endpoint of the study was a composite of all-cause mortality, recurrent myocardial infarction and congestive heart failure requiring hospitalization. RESULTS During a median follow-up of 3.0 (IQR: 2.0-4.5) years, 24 events occurred. The best predictor was MO (P < 0.0001), followed by infarct size by CMR (P = 0.0043) and infarct size by SPECT (P = 0.012) (all P-values corrected for clinical risk). In a multivariate model including clinical and periprocedural parameters, MO remained the only significant predictor in addition to clinical risk. CONCLUSIONS The extent of MO as determined by CMR has an excellent prognostic value in predicting cardiac events following acute myocardial infarction and may be used as an alternative to infarct size assessment by Tc99m-Sestamibi-SPECT.

Assessment of Isolated Right Ventricular Myocardial Infarction by Magnetic Resonance Imaging

A 47-year-old man with no history of cardiac disease was admitted because of chest pain 3 days earlier. At presentation, he was asymptomatic and hemodynamically stable. On physical examination, an elevated venous pressure was noted. Measurement of cardiac enzymes (creatine kinase 1085 U/L [normal <174], creatine kinase-MB 66 U/L [normal <10], and lactic dehydrogenase 686 U/L [normal <225]) at the time of admission suggested subacute myocardial infarction. However, ECG including right precordial leads showed no …

Assessment of Cor Triatriatum Sinistrum by Magnetic Resonance Imaging

A 44-year-old asymptomatic man with hypertension was referred to our institution for cardiac examination. Transthoracic Doppler echocardiography, limited by poor imaging quality, suggested a linear echodense structure within the left atrium. Further noninvasive evaluation was performed by MRI at 1.5 T. Dark blood–prepared spin-echo MR images of the heart revealed a membrane in the cranial part of the left atrium emerging from …

Dual-source RF transmission in cardiac SSFP imaging at 3 T: systematic spatial evaluation of image quality improvement compared to conventional RF transmission.

The purpose of this investigation was to systematically evaluate the spatial distribution of image quality improvement with dual-source radiofrequency (RF) transmission in cardiac steady-state free precession sequences at 3.0 T. Imaging with and without dual-source RF transmission was performed in 30 patients. Contrast-to-noise ratio for the left ventricular myocardium was significantly higher using dual-source RF transmission, but improvement was not uniformly distributed. The posterior myocardium showed significantly less contrast-to-noise ratio gain than all other cardiac regions. Signal-to-noise ratio increase was higher in the right than in the left ventricle. Subjective image quality was significantly enhanced by parallel RF transmission.

Magnetresonanztomographie und Spiralcomputertomographie in der Diagnostik und Nachsorge von Erwachsenen mit angeborenen Herz-und Gefäßanomalien

ZusammenfassungFür die Beurteilung des prä-und posto-operativen anatomischen und funktionellen Status von Erwachsenen mit angeborenen Herzfehlern sind detaillierte Informationen über Anatomie und Funktion aller kardialen und vaskulären Strukturen unverzichtbar. Lange Zeit stellte die Angiokardiographie den Goldstandard zur Erfassung und Beurteilung dieser Parameter dar. Als bildgebende Verfahren finden inzwischen neben der Angiokardiographie besonders die Echokardiographie und zunehmend häufig die Magnetresonanztomographie (MRT) sowie die Computertomographie (CT) Anwendung. All diese Verfahren sollten künftig nicht mehr als konkurrierende, sondern ais einander ergänzende Verfahren gesehen werden.AbstractManagement of patients with congenital heart disease requires detailed information on cardiac and great vessel morphology. In previous years the diagnosis and treatment of congenital malformations often depended on cardiac catheterization and in many institutions cardiac catheterization still remains the gold standard against which other modalities are measured.In the past decade, however, imaging methodologies have increasingly shifted toward the use of less invasive and noninvasive techniques. Currently, echocardiography is the initial method of choice in evaluating the anatomy, especially in younger patients. Meanwhile, several newer imaging techniques like magnetic resonance imaging (MRI) and computed tomography (CT) are in use. They offer extremely useful information about abnormalities of the heart and great vessels as well as for the assessment of cardiac anatomy and function.Echo, angiography, MRT and CT should be seen as complementary investigations in adult congenital heart disease.Management of patients with congenital heart disease requires detailed information on cardiac and great vessel morphology. In previous years the diagnosis and treatment of congenital malformations often depended on cardiac catheterization and in many institutions cardiac catheterization still remains the gold standard against which other modalities are measured. In the past decade, however, imaging methodologies have increasingly shifted toward the use of less invasive and noninvasive techniques. Currently, echocardiography is the initial method of choice in evaluating the anatomy, especially in younger patients. Meanwhile, several newer imaging techniques like magnetic resonance imaging (MRI) and computed tomography (CT) are in use. They offer extremely useful information about abnormalities of the heart and great vessels as well as for the assessment of cardiac anatomy and function. Echo, angiography, MRT and CT should be seen as complementary investigations in adult congenital heart disease.

Real clinical experiences of dual versus triple antithrombotic therapy after percutaneous coronary intervention

We aimed to assess the impact of omitting aspirin on clinical outcomes in a real‐world collective of patients receiving oral anticoagulation (OAC) therapy who were treated with a current‐generation drug‐eluting stent (DES) or an everolimus‐eluting bioresorbable vascular scaffold (BVS).

FIRST IN MAN OBSERVATIONS WITH SIMULTANEOUS 18F-FDG PET AND MR IMAGING IN PERIPHERAL ARTERY DISEASE USING A WHOLE-BODY INTEGRATED SCANNER

Advanced non-invasive vascular imaging simultaneously combining positron emission tomography (PET) with magnetic resonance imaging (MRI) has recently been made possible. This observational study attempted to identify patients with peripheral artery disease (PAD) at risk for vascular events using

Evaluation of a fibroelastoma with magnetic resonance imaging

A 64-year-old woman was admitted to hospital with acute chest pain and self-limiting ventricular tachycardia. Transthoracical Doppler echocardiography demonstrated mitral reurgitation and a mobile mass close to the anterior leaflet. Coronary angiography was normal. For …