Publications (25)79.59 Total impact
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Article: Head-to-Head Comparison of Two-Dimensional and Three-Dimensional Echocardiographic Methods for Left Atrial Chamber Quantification with Magnetic Resonance Imaging.
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ABSTRACT: BACKGROUND: Limited data are available on the accuracy of quantification methods for left atrial (LA) volumes using two-dimensional (2D) and particularly real-time three-dimensional echocardiographic (RT3DE) methods in comparison with a reference standard. The aim of this study was to perform a head-to-head comparison between 2D and RT3DE methods with magnetic resonance imaging (MRI) as the reference standard. METHODS: LA volumes derived from 2D echocardiographic methods (i.e., biplane modified Simpson's, biplane area-length, and prolate ellipse methods) and from RT3DE methods (i.e., 4D LA Analysis and QLAB) in 60 consecutive patients were compared with MRI measurements. Offline analysis time was recorded. RESULTS: The biplane modified Simpson's and area-length methods showed good intraclass correlations with MRI for maximum (r = 0.70 and r = 0.69, P < .001) and minimum (r = 0.83 and r = 0.82, P < .001) volumes. Although RT3DE methods led to moderate increases in correlations for maximum (r = 0.94 and 0.70, P < .001) and minimum (r = 0.95 and r = 0.90, P < .001) volumes and narrower Bland-Altman limits of agreement than 2D echocardiographic methods, offline analysis time was higher for RT3DE (155-161 vs 103-144 sec). Compared with MRI, maximum and minimum LA volumes were underestimated by -4.7% and -8.9%, respectively, using 4D LA Analysis, by -15.7% and -14.9% using QLAB, by -12.3% and -4.4% using the biplane Simpson's method, by -13.7% and -6.8% using the area-length method, and by -48.2% and -50.5% using the prolate ellipse method. CONCLUSIONS: The biplane Simpson's and area-length methods offer reasonable accuracy for LA chamber quantification across a broad range of volumes, while RT3DE methods lead to a moderate improvement in accuracy at the cost of more elaborate offline analysis.Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 02/2013; · 2.98 Impact Factor -
Article: The protein binding substance Ibuprofen does not affect the T1 time or partition coefficient in contrast-enhanced cardiovascular magnetic resonance.
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ABSTRACT: BACKGROUND: Contrast enhanced cardiovascular magnetic resonance (CMR) with T1 mapping enables quantification of diffuse myocardial fibrosis. Various factors, however, can interfere with T1 measurements. The purpose of the current study was to assess the effect of co-medication with a typical protein binding drug (Ibuprofen) on T1 values in vitro and in vivo. METHODS: 50 vials were prepared with different concentrations of gadobenate dimeglumine, Ibuprofen and human serum albumin in physiologic NaCl solution and imaged at 1.5T with a spin echo sequence at multiple TRs to measure T1 values and calculate relaxivities. 10 volunteers (5 men; 31+/-6.3 years) were imaged at 1.5T. T1 values for myocardium and blood pool were determined for various time points after administration of 0.15mmol/kg gadobenate dimeglumine using a modified look-locker inversion-recovery sequence before and after administration of Ibuprofen over 24 hours. The partition coefficient was calculated as DeltaR1myocardium/DeltaR1blood, where R1=1/T1. RESULTS: In vitro no significant correlation was found between relaxivity and Ibuprofen concentration, neither in absence (r=-0.15, p=0.40) nor in presence of albumin (r=-0.32, p=0.30). In vivo there was no significant difference in post contrast T1 times of myocardium and blood, respectively and also in the partition coefficient between exam 1 and 2 (p>0.05). There was good agreement of the T1 times of myocardium and blood and the partition coefficient, respectively between exam 1 and 2. CONCLUSIONS: Contrast enhanced T1 mapping is unaffected by co-medication with the protein binding substance Ibuprofen and has an excellent reproducibility.Journal of Cardiovascular Magnetic Resonance 10/2012; 14(1):71. · 3.72 Impact Factor -
Article: Normal response of cardiac flow and function to adenosine stress as assessed by cardiac MR.
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ABSTRACT: AIMS: To establish the response of cardiac flow and function to adenosine stress using phase-contrast magnetic resonance (pcMR) and cine steady-state free precession (SSFP) cardiac magnetic resonance (CMR). METHODS: Healthy volunteers (n = 10) were scanned on 1.5T at rest and under adenosine stress utilizing short-axis SSFP sequences and pcMR of the aorta and pulmonary trunk. RESULTS: Adenosine-induced increase in heart rate was 62.7% (P < 0.001). Left and right-ventricular stroke volumes (SVs) increased by 12.2% (P = 0.048) and 11.9% (P = 0.044), left-ventricular ejection fraction by 11.8% (P = 0.002), and left-ventricular and right-ventricular cardiac output (CO) by 81.0% (P < 0.001) and 81.8% (P = 0.005). Average flow velocities in the ascending aorta and pulmonary trunk increased by 77.3% (P < 0.001) and 73.6% (P < 0.001), and peak flow velocities in the ascending aorta and pulmonary trunk by 27.2% (P < 0.001) and 22.4% (P = 0.003). End-systolic volumes in the left ventricle (LV) and right ventricle (RV) decreased by 16.4% (P = 0.020) and 19.2% (P = 0.028). Planimetric cine SSFP and pcMR-derived SV showed an excellent correlation. CONCLUSION: In healthy volunteers, response to adenosine stress is characterized by an increase in heart rate, CO and SV of both ventricles. Excellent correlation is demonstrated between these increases and the increased blood flow velocities in the aorta and the pulmonary trunk. Thus, results support the use of flow measurements as an internal control of planimetric measurements of ventricular SV and CO.Journal of Cardiovascular Medicine 08/2012; · 1.51 Impact Factor -
Article: Preoperative staging of non-small-cell lung cancer: comparison of whole-body diffusion-weighted magnetic resonance imaging and (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography.
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ABSTRACT: OBJECTIVE: To investigate the diagnostic value of whole-body magnetic resonance imaging (MRI) including diffusion-weighted imaging with background signal suppression (DWIBS) for preoperative assessment of non-small-cell lung cancer (NSCLC) in comparison to (18)F-fluorodeoxyglucose (18)FDG) positron emission tomography/computed tomography (PET/CT). METHODS: Thirty-three patients with suspected NSCLC were enrolled. Patients were examined before surgery with PET/CT and whole-body MRI including T1-weighted turbo spin echo (TSE), T2-weighted short tau inversion recovery (STIR) and DWIBS sequences (b = 0/800). Histological or cytological specimens were taken as standard of reference. RESULTS: Whole-body MRI with DWIBS as well as PET/CT provided diagnostic image quality in all cases. Sensitivity for primary tumour detection: MRI 93%, PET/CT 98%. T-staging accuracy: MRI 63%, PET/CT 56%. N-staging accuracy: MRI 66%, PET/CT 71%. UICC staging accuracy: MRI 66%, PET/CT 74%. Sensitivity for metastatic involvement of individual lymph node groups: MRI 44%, PET/CT 47%. Specificity for individual non-metastatic lymph node groups: MRI 93%, PET/CT 96%. Assessment accuracy for individual lymph node groups: MRI 85%, PET/CT 88%. Observer agreement rate for UICC staging: MRI 74%, PET/CT 90%. CONCLUSION: Whole-body MRI with DWIBS provides comparable results to PET/CT in staging of NSCLC, but shows no superiority. Most relevant challenges for both techniques are T-staging accuracy and sensitivity for metastatic lymph node involvement. KEY POINTS : • Numerous radiological methods are available for the crucial staging of lung cancer • Whole-body DWIBS MRI provides comparable results to PET/CT in NSCLC staging. • No evident superiority of whole-body DWIBS over PET/CT in NSCLC staging. • Challenges for both techniques are T-staging and detection of small metastases.European Radiology 07/2012; · 3.22 Impact Factor -
Article: Interventionelle kardiovaskuläre Magnetresonanz: neue therapeutische Anwendungen
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ABSTRACT: Die interventionelle kardiovaskuläre Magnetresonanzbildgebung (iMR) ist eine neue Disziplin, die minimalinvasive Therapien ermöglicht und eine attraktive Alternative zu konventionellen röntgengesteuerten kardiovaskulären Interventionen darstellt. Stärken der iMR sind die dreidimen sionale Ortsauflösung und der hervorragende Weichteilkontrast, des Weiteren sind keine ionisierenden Strahlen erforderlich. Für die Durchführung dieser neuen Techniken werden MR-kompatible endovaskuläre Katheter und Instrumente benötigt. Die iMR ermöglicht die gezielte Applikation von Wachstumsfaktoren, Genen oder Stammzellen in Gefäßwände oder in das Myokard sowie endovaskuläre Kathetereingriffe. Die iMR kann mit aktiven und passiven Methoden durchgeführt werden. Die iMR wird in Echtzeit durchgeführt. Endovaskuläre MR-Katheter und Führungsdrähte können sich erwärmen und dadurch zu Sicherheitsrisiken werden. Neuerungen wie offene kurze MR-Tomographen ermöglichen lokale intramyokardiale und intrakoronare Therapieformen. Neue kardiovaskuläre MR-Kontrastmittel tragen zur Verbesserung der iMR-Eingriffe durch Anreicherung in pathologischem Zielgewebe (Myokardinfarkte, atherosklerotische Plaques) bei; darüber hinaus lassen sich die Verteilung, Differenzierung und das Überleben von markierten Stammzellen im Myokard und in Gefäßwänden darstellen. Die iMR-Technik kann jedoch nur unter folgenden Bedingungen durchgeführt werden: 1. mit einer hohen räumlichen und zeitlichen Auflösung, 2. mit speziellen Kathetersystemen für eine intravaskuläre oder intramyokardiale Therapie und 3. mit einem wirksamen Medikament. Diese Übersichtsarbeit berichtet über die aktuellen Aspekte der iMR, nennt Beispiele in Bezug auf kardiale Interven tionen und stellt die Herausforderungen in Bezug auf die Zukunft der iMR dar. Interventional cardiovascular magnetic resonance (iCMR) makes new minimally invasive therapies possible and is an attractive alternative option with high soft-tissue contrast and the possibility of a three-dimensional MR angiography compared to conventional angiography-guided interventions. Interventional MR-navigated cardiovascular therapies represent a new discipline whose systematic development will foster minimally invasive interventional procedures without radiation exposure. MR-compatible endovascular catheters and guide wires are needed for delivery of devices and therapies. Catheter tracking is based on active and passive approaches. Currently performed MR-guided cardiovascular procedures have been used to monitor, navigate and track endovascular catheters and to deliver local therapies to the targets. Heating of endovascular MR catheters, guide wires and devices during imaging still presents high safety risks. Cardiovascular MR contrast media improve the capability of MRI by enhancing blood signal, pathologic targets (such as myocardial infarctions and atherosclerotic plaques) and tracking injected therapies (such as cells or genes). Labeling injected therapies or cells with MR contrast media leads interventionalists to trace the distribution, differentiation and survival. The requirements for this iCMR technique are (1) high spatial and temporal resolution imaging, (2) special catheters and devices, and (3) effective therapeutic drugs. This review summarizes current aspects of iCMR, provides examples of its use in the heart and beyond, discusses the infrastructure required for successful implementation of iCMR approaches, and outlines the challenges that must be overcome for iCMR to advance further.Herz 04/2012; 33(5):323-333. · 0.92 Impact Factor -
Article: Functional assessment of the left atrium by real-time three-dimensional echocardiography using a novel dedicated analysis tool: initial validation studies in comparison with computed tomography.
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ABSTRACT: A novel real-time three-dimensional echocardiography (RT3DE) analysis tool specifically designed for evaluation of the left atrium enables comprehensive evaluation of left atrial (LA) size, global, and regional function using a dynamic 16-segment model. The aim of this study was the initial validation of this method using computed tomography (CT) as the method of reference. The study population consisted of 34 prospectively enrolled patients with clinical indication for pulmonary vein isolation. A dynamic polyhedron model of the left atrium was generated using RT3DE. LA maximum and minimum volumes (LA(max)/LA(min)) and emptying fraction (LAEF) were determined and compared with the results obtained by CT. High correlations between RT3DE and CT were found for LA(max) (r = 0.92, P < 0.001), LA(min) (r = 0.95, P < 0.001), and LAEF (r = 0.82, P < 0.001). LA(max) and LA(min) were lower by RT3DE than by CT (95.0 ± 44.7 vs. 119.8 ± 50.5 mL, P < 0.001 and 58.1 ± 41.3 vs. 83.3 ± 52.6 mL, P < 0.001, respectively), whereas LAEF was measured higher by RT3DE (42.8 ± 15.2 vs. 34.2 ± 15.4%, P < 0.001, respectively). RT3DE measurements closely correlated in terms of intra-observer (intra-class correlation r = 0.99, r = 0.99, r = 0.96, respectively) and inter-observer variability (r = 0.97, r = 0.98, r = 0.88, respectively). LA volumes and EF as assessed by RT3DE correlate highly with CT measurements, albeit there is some bias between the imaging modalities. Most importantly, RT3DE measurements using the novel dedicated LA analysis tool are robust in terms of observer variability and thus suitable for follow-up analyses.European Heart Journal – Cardiovascular Imaging 06/2011; 12(7):497-505. · 2.32 Impact Factor -
Article: Cardiovascular magnetic resonance imaging for diagnosis and clinical management of suspected cardiac masses and tumours.
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ABSTRACT: To evaluate the diagnostic accuracy of cardiovascular magnetic resonance (CMR) imaging from a risk-stratification and therapeutic-management perspective in patients with suspected cardiac tumours. Cardiovascular magnetic resonance exams of 41 consecutive patients (aged 61 ± 14 years, 21 men) referred for evaluation of a suspected cardiac mass were reviewed for tumour morphology and signal characteristics in various unenhanced and contrast-enhanced sequences. Cardiovascular magnetic resonance-derived diagnosis and treatment were compared with clinical outcome and histology in patients undergoing surgery or autopsy (n = 20). In 18 of 41 patients, CMR excluded masses or reclassified them as normal variants; all were treated conservatively. In 23 of 41 patients, CMR diagnosed a neoplasm (14 'benign', 8 'malignant', and 1 'equivocal'); 18 of these patients were operated on, 2 managed conservatively, and 3 by palliation. During follow-up of 705 (inter-quartile range 303-1472) days, 13 patients died. No tumour-related deaths occurred in conservatively managed patients. Patients with a CMR-based diagnosis and treatment of benign tumour had a similar survival as patients without detectable tumour. Compared with histology, CMR correctly classified masses as 'benign or malignant' in 95% of the cases. Tumour perfusion, invasiveness, localization, and pericardial fluid were valuable to distinguish between malignant and benign tumours. Soft tissue contrast and signal intensity patterns in various sequences were valuable for excluding neoplastic lesions and helped to obtain tissue characterization at the histological level in selected tumour cases, respectively. Comprehensive CMR provides a confident risk-stratification and clinical-management tool in patients with suspected tumours. Patients where CMR excludes tumours can be managed conservatively.European Heart Journal 06/2011; 32(12):1551-60. · 10.48 Impact Factor -
Article: MR-imaging of the thoracic aorta: 3D-ECG- and respiratory-gated bSSFP imaging using the CLAWS algorithm versus contrast-enhanced 3D-MRA.
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ABSTRACT: To compare a contrast-enhanced 3D angiography (CE-3D-MRA) with the ECG- and respiratory gated 3D balanced steady state free precession (bSSFP) sequence using the CLAWS algorithm (3D-bSSFP-CLAWS) with respect to acquisition time, image quality, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). 14 patients (4 women, mean age ± SD: 52 ± 18) with known or suspected thoracic aortic disease were imaged on a 1.5T scanner with both sequences. Two readers scored image quality of predefined levels of the thoracic aorta. Acquisition time, SNR and CNR were calculated for each examination. Image quality achieved with the 3D-bSSFP-CLAWS was scored significantly better than with the CE-3D-MRA for the aortic annulus (P = 0.003), the sinuses of Valsalva (P = 0.001), the proximal coronary arteries (P = 0.001) and the sinotubular junction (P = 0.001). Effective acquisition time for the 3D-bSSFP-CLAWS and corrected acquisition time (corrected for imaging parameters) was significantly longer compared to the CE-3D-MRA (P = 0.004 and P = 0.028). SNR and CNR were significantly higher for the CE-3D-MRA (P = 0.007 and P = 0.001). Providing the highest scan efficiency for a given breathing pattern, image quality for the proximal ascending aorta achieved with the 3D-bSSFP-CLAWS is significantly superior in contrast to the CE-3D-MRA.European journal of radiology 01/2011; 81(2):239-43. · 2.65 Impact Factor -
Article: Dynamic assessment of right ventricular volumes and function by real-time three-dimensional echocardiography: a comparison study with magnetic resonance imaging in 100 adult patients.
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ABSTRACT: The aim of this study was to validate a novel real-time three-dimensional echocardiographic (RT3DE) analysis tool for the determination of right ventricular volumes and function in unselected adult patients. A total of 100 consecutive adult patients with normal or pathologic right ventricles were enrolled in the study. A dynamic polyhedron model of the right ventricle was generated using dedicated RT3DE software. Volumes and ejection fractions were determined and compared with results obtained on magnetic resonance imaging (MRI) in 88 patients with adequate acquisitions. End-diastolic, end-systolic, and stroke volumes were slightly lower on RT3DE imaging than on MRI (124.0 +/- 34.4 vs 134.2 +/- 39.2 mL, P < .001; 65.2 +/- 23.5 vs 69.7 +/- 25.5 mL, P = .02; and 58.8 +/- 18.4 vs 64.5 +/- 24.1 mL, P < .01, respectively), while no significant difference was observed for ejection fraction (47.8 +/- 8.5% vs 48.2 +/- 10.8%, P = .57). Correlation coefficients on Bland-Altman analysis were r = 0.84 (mean difference, 10.2 mL; 95% confidence interval [CI], -31.3 to 51.7 mL) for end-diastolic volume, r = 0.83 (mean difference, 4.5 mL; 95% CI, -23.8 to 32.9 mL) for end-systolic volume, r = 0.77 (mean difference, 5.7 mL; 95% CI, -24.6 to 36.0 mL) for stroke volume, and r = 0.72 (mean difference, 0.4%; 95% CI, -14.2% to 15.1%) for ejection fraction. Right ventricular volumes and ejection fractions as assessed using RT3DE imaging compare well with MRI measurements. RT3DE imaging may become a time-saving and cost-saving alternative to MRI for the quantitative assessment of right ventricular size and function.Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 02/2010; 23(2):116-26. · 2.98 Impact Factor -
Article: [Noninvasive diagnostic of coronary artery disease].
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ABSTRACT: Noninvasive imaging of coronary artery disease has extensively evolved during the last decade. Today, at least four imaging techniques with excellent image quality such as echocardiography, myocardial perfusion scintigraphy and PET, cardiac magnetic resonance and cardiac CT are widely available in order to estimate the risk for future ischemic events, to corroborate the suspected diagnosis of coronary artery disease, to demonstrate the extent and localisation of myocardial ischemia, to diagnose myocardial infarction and measure it's size, to identify the myocardium at risk during acute ischemia, to differentiate between viable and nonviable myocardium and thereby provide the basis for indications of revascularisations, to follow revascularized patients over long time, to assess the risk for sudden cardiac death and the development of heart failure after myocardial infarction and to depict atheromatosis and atherosclerosis of the coronary artery tree. Echocardiography is the most widely used imaging method in cardiology. It provides excellent information on morphology and function of nearly all cardiac structures. Stress echocardiography has been proven to be a reliable tool for the demonstration of myocardial ischemia and for the acquisition of prognostic data. Newer ultrasound techniques may further improve investigator dependence and thereby reproducibility. The completeness of echocardiography will always depend on acoustic windows, which are given in a specific patient. Myocardial perfusion scintigraphy provides the largest database especially on prognosis in coronary artery disease. It has been the for the depictions of ischemic and infarcted myocardium. Radiation exposure will always be an issue. Newer hybrid techniques combining nuclear methods with cardiac CT may add arguments, which will be needed for clinical decision-making. Cardiac magnetic resonance has evolved as an important tool in the diagnosis of cardiovascular diseases. It is investigator independent, does not apply any biologically hazardous energy and has the largest potential for tissue characterization due to its high contrast resolution. It therefore is an excellent technique to investigate all the aspects of coronary artery disease. Its availability is increasing, however in order to fully utilize its large potential an optimal collaboration among -specialist (cardiologists, radiologists, physicists) is mandatory. Cardiac CT has evolved as an excellent method for the depiction of the coronary arteries. Due to its high spatial and time resolution it provides high quality luminography of the coronaries and newer technique are also -investigating plaque composition of diseased coronary arteries. Overestimation of coronary artery stenosis in calcified vessels is an inherent problem of the technique and the risk of radiation exposure has to be weighted against the benefit of non-invasively depicting the coronary arteries. It will be the future task of all specialists in this field to define the most efficient and cost-effective way to apply these excellent techniques for the investigation of all the different aspects of patients with coronary artery disease.Therapeutische Umschau 05/2009; 66(4):241-51. -
Article: Cardiovascular flashlight. Transient right bundle branch block in a young patient.
European Heart Journal 03/2009; 30(9):1032. · 10.48 Impact Factor -
Article: [New therapies for interventional cardiovascular magnetic resonance imaging].
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ABSTRACT: Interventional cardiovascular magnetic resonance (iCMR) makes new minimally invasive therapies possible and is an attractive alternative option with high soft-tissue contrast and the possibility of a three-dimensional MR angiography compared to conventional angiography-guided interventions. Interventional MR-navigated cardiovascular therapies represent a new discipline whose systematic development will foster minimally invasive interventional procedures without radiation exposure. MR-compatible endovascular catheters and guide wires are needed for delivery of devices and therapies. Catheter tracking is based on active and passive approaches. Currently performed MR-guided cardiovascular procedures have been used to monitor, navigate and track endovascular catheters and to deliver local therapies to the targets. Heating of endovascular MR catheters, guide wires and devices during imaging still presents high safety risks. Cardiovascular MR contrast media improve the capability of MRI by enhancing blood signal, pathologic targets (such as myocardial infarctions and atherosclerotic plaques) and tracking injected therapies (such as cells or genes). Labeling injected therapies or cells with MR contrast media leads interventionalists to trace the distribution, differentiation and survival. The requirements for this iCMR technique are (1) high spatial and temporal resolution imaging, (2) special catheters and devices, and (3) effective therapeutic drugs. This review summarizes current aspects of iCMR, provides examples of its use in the heart and beyond, discusses the infrastructure required for successful implementation of iCMR approaches, and outlines the challenges that must be overcome for iCMR to advance further.Herz 08/2008; 33(5):323-33. · 0.92 Impact Factor -
Article: 1077 susceptibility-related signal loss compensation in myocardial T2*-quantification
Journal of Cardiovascular Magnetic Resonance. 01/2008; -
Article: MR angiography with blood pool contrast agents.
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ABSTRACT: Contrast-enhanced magnetic resonance angiography (CE-MRA) with standard extracellular contrast material is well established for vascular imaging. Recently, the first blood pool contrast agent (BPA) has become clinically available. This paper reviews characteristics and classification of BPA as well as first clinical experience in various vascular territories. BPAs comprise gadolinium-based compounds, synthetic compounds, and ultrasmall superparamagnetic iron-oxide (USPIO) particles. Such BPAs are retained in blood with a prolonged time-window of enhancement as compared to extracellular gadolinium chelates. Promising results from USPIO at first-pass and steady-state angiography have been published, but no USPIO is approved yet. Gadofosveset is the first clinically approved BPA. After bolus injection, gadofosveset binds noncovalently to serum-albumine, thus enhancing relaxivity. First published results from carotid, coronary, renal, and peripheral angiography are encouraging; particularly helpful is prolonged enhancement during steady state. More BPAs have been clinically evaluated, but no approval has been granted. Bolus-injectable BPAs allow for first-pass CE-MRA similar to standard extracellular contrast media, but with higher relaxivity, allowing lower doses and reduced injection rates. An additional feature of BPA is the steady-state phase with a broad time window enabling high-resolution angiography or double-gated angiography of coronary arteries to compensate for the complex motion pattern.European Radiology 01/2008; 17(12):3017-24. · 3.22 Impact Factor -
Article: Oral administration of 17beta-estradiol over 3 months without progestin co-administration does not improve coronary flow reserve in post-menopausal women: a randomized placebo-controlled cross-over CMR study.
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ABSTRACT: Several large epidemiological outcome studies did not demonstrate a benefit of combined estrogen-progestin replacement treatment (HRT) on cardiovascular events in elderly postmenopausal women. Whether progestin antagonism is responsible for these negative results or the natural estrogen 17ss-estradial (E2) itself is not effective in the coronary circulation is unknown. To assess the effect of 3 months of E2 treatment on the coronary circulation, i.e., on coronary flow reserve (CFR), in postmenopausal women without established coronary artery disease (CAD). In a double-blind placebo-controlled cross-over design postmenopausal women (60 +/- 5 years, n = 14) were randomized to either start with placebo or E2 (Estrofem, Novo Nordisk, Copenhagen, Denmark) 2 mg/d given orally over 3 months and to switch thereafter for another 3 months of therapy. At baseline, a stress echocardiography was performed to exclude CAD. CFR was determined by coronary sinus CMR flow measurements (with motion-adapted gating and interactive acquisition window control; spatial/temporal resolution of 0.8 x 0.9 mm2/25-30 ms) which were performed at rest and during vasodilation (dipyridamole 0.56 mg/kg over 4 minutes IV) at baseline, and after 3 and 6 months of therapy, respectively. Hemodynamics such as heart rate and systolic and diastolic blood pressure were not different for the control and E2 group. For CFR and for resting and hyperemic coronary sinus blood flow, no differences between the placebo and E2 group were found (2-way ANOVA for repeated measurements). Reproducibility of phase-contrast CMR measurements of CFR was -1.1 +/- 4.9%. In elderly postmenopausal women without significant CAD, oral administration of E2 over 3 months without a progestin co-administration does not improve CFR. This finding yields partly explanation for some large epidemiological trials which could not demonstrate a clinical cardiovascular benefit of HRT in elderly women.Journal of Cardiovascular Magnetic Resonance 02/2007; 9(4):665-72. · 3.72 Impact Factor -
Article: Coronary artery imaging with contrast-enhanced MDCT: extracardiac findings.
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ABSTRACT: The purpose of our study was to evaluate the incidence of extracardiac findings on contrast-enhanced MDCT of the coronary arteries and to assess the effect of different field-of-view settings. Patients with suspected coronary artery disease (n = 166) were examined with contrast-enhanced MDCT (16 x 0.75 mm focused on the heart) during injection of contrast material (80 mL injected at a rate of 4 mL/sec) followed by saline (20 mL injected at 4 mL/sec). Retrospectively gated images were reconstructed at a 1-mm slice thickness and a 0.5-mm increment with isotropic voxels of 1 mm3. Images were reviewed for extracardiac findings, which were then classified as none, minor, or major with respect to their impact on patient management and treatment. In a different group of patients (n = 20), chest scans (16 x 1.5 mm) were used for measuring volumes of displayed body structures on wholechest scans, coronary artery MDCT images, and coronary artery MDCT images reconstructed with the maximum field of view. Extracardiac findings were detected in 41 patients (24.7%). Findings were classified as minor (19.9%) or major (4.8%). Among the major findings, which had an immediate impact on patient management and treatment, were bronchial carcinoma and pulmonary emboli. Volume analysis revealed that 35.5% of the total chest volume was displayed on dedicated coronary artery MDCT focused on the heart, whereas 70.3% of the chest was visible when coronary artery MDCT raw data were reconstructed with the maximal field of view (p < 0.001). Coronary artery MDCT can reveal important findings and disease in extracardiac structures. Thus, the entire examination should be reconstructed with the maximum field of view and should be reviewed by a qualified radiologist.American Journal of Roentgenology 08/2006; 187(1):105-10. · 2.78 Impact Factor -
Article: Value of repeated cardiac magnetic resonance imaging in patients with suspected arrhythmogenic right ventricular cardiomyopathy.
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ABSTRACT: Diagnosis of early stages of arrhythmogenic right ventricular cardiomyopathy (ARVC) with minimal structural abnormalities is challenging. The purpose of this study was to assess the value of repeated cardiac magnetic resonance imaging (CMR) in patients referred for right ventricular arrhythmias and clinical suspicion of ARVC. Prospective follow-up study of 18 patients (8 females) studied with CMR for suspected ARVC. Patients with implanted defibrillators (ICD) were excluded. Mean follow-up was 37 +/- 16 (12-59) months. Patients were assigned to 2 categories (ARVC likely or ARVC unlikely) according to a CMR-score based on right ventricular abnormalities. Clinical follow-up revealed no disease progression in 17 patients (94%). In 1 patient, an ICD was implanted because of disease progression. Of 9 patients with initial findings suggestive of ARVC, follow-up CMR remained positive in 3 and was diagnosed as normal in 6, mainly due to the inability to confirm the presence of fatty infiltrates at follow-up (5 of 6 patients). Initially, 9 patients had a normal CMR and 8 of those remained normal during follow-up. Repeated CMR after an average follow-up of 3 years was normal in 6 of 9 patients with clinical findings consistent with early stages of ARVC at the time of baseline CMR. Thus, CMR diagnosis of early stage ARVC is difficult and should be made with caution.Journal of Cardiovascular Magnetic Resonance 02/2006; 8(2):361-6. · 3.72 Impact Factor -
Article: Limited diagnostic yield of non-invasive coronary angiography by 16-slice multi-detector spiral computed tomography in routine patients referred for evaluation of coronary artery disease.
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ABSTRACT: Multislice spiral computed tomography (MSCT) is a promising non-invasive method to diagnose coronary artery disease (CAD). As no detailed comparative evaluation in consecutive patients referred for evaluation of CAD has been reported, this prospective study evaluating 2384 coronary segments in 149 consecutive patients was performed. The coronary artery tree was analysed in 16 segments both for coronary angiography (CA) and MSCT; a luminal narrowing > or = 50% based on visual assessment was considered significant. By MSCT, 77% of 2110 angiographically assessable segments could be evaluated, 94% per patient in proximal and 70% in distal segments (P<0.001). Sensitivity of MSCT to detect significant stenoses was 30% in all, but only 10% in peripheral segments. The main limitations were calcifications in 34% of segments and motion artefacts in 24% of patients. Overall diagnostic sensitivity for the presence of significant CAD was 86% but specificity was only 49%. When compared with invasive CA, 16-slice MSCT is of limited diagnostic value for the diagnosis of CAD in consecutive patients. Despite a clinically useful sensitivity for the overall diagnosis of significant CAD, specificity is low. Thus, relevant decisions regarding the need of and suitability for possible revascularization procedures cannot be based on MSCT findings alone.European Heart Journal 11/2005; 26(19):1987-92. · 10.48 Impact Factor -
Article: Invasive apergillosis with myocardial involvement after kidney transplantation.
Nephrology Dialysis Transplantation 04/2005; 20(3):631-4. · 3.40 Impact Factor -
Article: Arrhythmogenic right ventricular cardiomyopathy: diagnostic and prognostic value of the cardiac MRI in relation to arrhythmia-free survival.
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ABSTRACT: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a potentially fatal disease, which is often difficult to diagnose. As a non-invasive test cardiac magnetic resonance imaging (CMR) has become an important tool in establishing the diagnosis. The aim of this study was to evaluate the diagnostic and prognostic value of CMR in patients with suspected ARVC and to assess the long-term outcome of patients with CMR-diagnosed ARVC. Thirty-six patients with suspected ARVC (26 male, 10 female, median age 41 years) underwent non-invasive and invasive clinical tests as gold standard for ARVC diagnosis. ARVC was clinically diagnosed in 19 patients and excluded in 17 patients. Both groups underwent CMR, and diagnosis was confirmed by CMR in 16/18 patients with clinically diagnosed ARVC (sensitivity 89%), and correctly excluded in 14/17 of patients with clinically excluded ARVC (specificity 82%). This result indicates a positive predictive value of the CMR of 84%, and a negative predictive value of 88%, respectively (p < 0.0001). Using a scoring system, multiple CMR parameters were compared in the two groups in regard of the clinical diagnosis. By univariate analysis, right ventricular fatty tissue infiltration (p = 0.0003) was predictive for diagnosis. Compared by outcome, 37% of patients with clinically and by CMR-diagnosed ARVC had an arrhythmic event during a mean follow-up of 16 +/- 11 months. These data suggest that CMR is a highly sensitive and specific method to diagnose or exclude ARVC, and thus, has an important prognostic impact on predicting arrhythmia free survival.The International Journal of Cardiovascular Imaging 01/2004; 19(6):537-43; discussion 545-7. · 2.29 Impact Factor
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Institutions
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2012
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Novartis Institutes for BioMedical Research
Cambridge, MA, USA
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2004–2012
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Universitätsspital Basel
Basel, BS, Switzerland
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2003
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Universität Basel
Basel, BS, Switzerland
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2000
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University of California, San Francisco
San Francisco, CA, USA
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