Author
Sebastian Kozerke
Other affiliations: École Polytechnique Fédérale de Lausanne, King's College London, University of Zurich ...read more
Bio: Sebastian Kozerke is an academic researcher from ETH Zurich. The author has contributed to research in topics: Diffusion MRI & Coronary artery disease. The author has an hindex of 54, co-authored 379 publications receiving 11618 citations. Previous affiliations of Sebastian Kozerke include École Polytechnique Fédérale de Lausanne & King's College London.
Papers published on a yearly basis
Papers
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TL;DR: A novel pulse sequence scheme is presented that allows the measurement and mapping of myocardial T1 in vivo on a 1.5 Tesla MR system within a single breath‐hold and provides high‐resolution T1 maps of human myocardium in native and post‐contrast situations within asingle breath-hold.
Abstract: A novel pulse sequence scheme is presented that allows the measurement and mapping of myocardial T1 in vivo on a 1.5 Tesla MR system within a single breath-hold. Two major modifications of conventional Look-Locker (LL) imaging are introduced: 1) selective data acquisition, and 2) merging of data from multiple LL experiments into one data set. Each modified LL inversion recovery (MOLLI) study consisted of three successive LL inversion recovery (IR) experiments with different inversion times. We acquired images in late diastole using a single-shot steady-state free-precession (SSFP) technique, combined with sensitivity encoding to achieve a data acquisition window of <200 ms duration. We calculated T1 using signal intensities from regions of interest and pixel by pixel. T1 accuracy at different heart rates derived from simulated ECG signals was tested in phantoms. T1 estimates showed small systematic error for T1 values from 191 to 1196 ms. In vivo T1 mapping was performed in two healthy volunteers and in one patient with acute myocardial infarction before and after administration of Gd-DTPA. T1 values for myocardium and noncardiac structures were in good agreement with values available from the literature. The region of infarction was clearly visualized. MOLLI provides high-resolution T1 maps of human myocardium in native and post-contrast situations within a single breath-hold. Magn Reson Med 52:141–146, 2004. © 2004 Wiley-Liss, Inc.
1,131 citations
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TL;DR: It is described that 4D Flow CMR can be clinically advantageous because placement of a single acquisition volume is straightforward and enables flow through any plane across it to be calculated retrospectively and with good accuracy.
Abstract: Pulsatile blood flow through the cavities of the heart and great vessels is time-varying and multidirectional. Access to all regions, phases and directions of cardiovascular flows has formerly been limited. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has enabled more comprehensive access to such flows, with typical spatial resolution of 1.5×1.5×1.5 – 3×3×3 mm3, typical temporal resolution of 30–40 ms, and acquisition times in the order of 5 to 25 min. This consensus paper is the work of physicists, physicians and biomedical engineers, active in the development and implementation of 4D Flow CMR, who have repeatedly met to share experience and ideas. The paper aims to assist understanding of acquisition and analysis methods, and their potential clinical applications with a focus on the heart and greater vessels. We describe that 4D Flow CMR can be clinically advantageous because placement of a single acquisition volume is straightforward and enables flow through any plane across it to be calculated retrospectively and with good accuracy. We also specify research and development goals that have yet to be satisfactorily achieved. Derived flow parameters, generally needing further development or validation for clinical use, include measurements of wall shear stress, pressure difference, turbulent kinetic energy, and intracardiac flow components. The dependence of measurement accuracy on acquisition parameters is considered, as are the uses of different visualization strategies for appropriate representation of time-varying multidirectional flow fields. Finally, we offer suggestions for more consistent, user-friendly implementation of 4D Flow CMR acquisition and data handling with a view to multicenter studies and more widespread adoption of the approach in routine clinical investigations.
638 citations
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TL;DR: This review intends to introduce currently used 4D flow MRI methods, including Cartesian and radial data acquisition, approaches for acceleratedData acquisition, cardiac gating, and respiration control, and an overview over the potential this new imaging technique has in different parts of the body from the head to the peripheral arteries.
Abstract: Traditionally, magnetic resonance imaging (MRI) of flow using phase contrast (PC) methods is accomplished using methods that resolve single-directional flow in two spatial dimensions (2D) of an individual slice. More recently, three-dimensional (3D) spatial encoding combined with three-directional velocity-encoded phase contrast MRI (here termed 4D flow MRI) has drawn increased attention. 4D flow MRI offers the ability to measure and to visualize the temporal evolution of complex blood flow patterns within an acquired 3D volume. Various methodological improvements permit the acquisition of 4D flow MRI data encompassing individual vascular structures and entire vascular territories such as the heart, the adjacent aorta, the carotid arteries, abdominal, or peripheral vessels within reasonable scan times. To subsequently analyze the flow data by quantitative means and visualization of complex, three-directional blood flow patterns, various tools have been proposed. This review intends to introduce currently used 4D flow MRI methods, including Cartesian and radial data acquisition, approaches for accelerated data acquisition, cardiac gating, and respiration control. Based on these developments, an overview is provided over the potential this new imaging technique has in different parts of the body from the head to the peripheral arteries.
590 citations
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TL;DR: Given sufficient data sparsity and base signal‐to‐noise ratio (SNR), CS is demonstrated to result in improved temporal fidelity compared to k‐t BLAST reconstructions for the example data sets used in this work.
Abstract: Recent theoretical advances in the field of compressive sampling-also referred to as compressed sensing (CS)-hold considerable promise for practical applications in MRI, but the fundamental condition of sparsity required in the CS framework is usually not fulfilled in MR images. However, in dynamic imaging, data sparsity can readily be introduced by applying the Fourier transformation along the temporal dimension assuming that only parts of the field-of-view (FOV) change at a high temporal rate while other parts remain stationary or change slowly. The second condition for CS, random sampling, can easily be realized by randomly skipping phase-encoding lines in each dynamic frame. In this work, the feasibility of the CS framework for accelerated dynamic MRI is assessed. Simulated datasets are used to compare the reconstruction results for different reduction factors, noise, and sparsity levels. In vivo cardiac cine data and Fourier-encoded velocity data of the carotid artery are used to test the reconstruction performance relative to k-t broad-use linear acquisition speed-up technique (k-t BLAST) reconstructions. Given sufficient data sparsity and base signal-to-noise ratio (SNR), CS is demonstrated to result in improved temporal fidelity compared to k-t BLAST reconstructions for the example data sets used in this work.
587 citations
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TL;DR: An optimized sequence protocol for cardiac SSFP imaging at 3.0T is derived, taking into account several partly adverse effects at higher field, such as increased field inhomogeneities, longer T1, and power deposition limitations.
Abstract: Balanced steady-state free precession (SSFP) techniques provide excellent contrast between myocardium and blood at a high signal-to-noise ratio (SNR). Hence, SSFP imaging has become the method of choice for assessing cardiac function at 1.5T. The expected improvement in SNR at higher field strength prompted us to implement SSFP at 3.0T. In this work, an optimized sequence protocol for cardiac SSFP imaging at 3.0T is derived, taking into account several partly adverse effects at higher field, such as increased field inhomogeneities, longer T1, and power deposition limitations. SSFP contrast is established by optimizing the maximum amplitude of the radiofrequency (RF) field strength for shortest TR, as well as by localized linear or second-order shimming and local optimization of the resonance frequency. Given the increased SNR, sensitivity encoding (SENSE) can be employed to shorten breath-hold times. Short-axis, long-axis, and four-chamber cine views obtained in healthy adult subjects are presented, and three different types of artifacts are discussed along with potential methods for reducing them. Magn Reson Med 51:799–806, 2004. © 2004 Wiley-Liss, Inc.
302 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
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28,685 citations
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TL;DR: The If Inhibitor Ivabradine in Patients With Coronary Artery Disease and Left Ventricular Dysfunction is evaluated as well as patients with Diabetes mellitus for Optimal management of Multivessel disease.
Abstract: 99mTc
: technetium-99m
201TI
: thallium 201
ABCB1
: ATP-binding cassette sub-family B member 1
ABI
: ankle-brachial index
ACC
: American College of Cardiology
ACCF
: American College of Cardiology Foundation
ACCOMPLISH
: Avoiding Cardiovascular Events Through Combination Therapy in Patients Living With Systolic Hypertension
ACE
: angiotensin converting enzyme
ACIP
: Asymptomatic Cardiac Ischaemia Pilot
ACS
: acute coronary syndrome
ADA
: American Diabetes Association
ADP
: adenosine diphosphate
AHA
: American Heart Association
ARB
: angiotensin II receptor antagonist
ART
: Arterial Revascularization Trial
ASCOT
: Anglo-Scandinavian Cardiac Outcomes Trial
ASSERT
: Asymptomatic atrial fibrillation and Stroke Evaluation in pacemaker patients and the atrial fibrillation Reduction atrial pacing Trial
AV
: atrioventricular
BARI 2D
: Bypass Angioplasty Revascularization Investigation 2 Diabetes
BEAUTIFUL
: Morbidity-Mortality Evaluation of the If Inhibitor Ivabradine in Patients With Coronary Artery Disease and Left Ventricular Dysfunction
BIMA
: bilateral internal mammary artery
BMI
: body mass index
BMS
: bare metal stent
BNP
: B-type natriuretic peptide
BP
: blood pressure
b.p.m.
: beats per minute
CABG
: coronary artery bypass graft
CAD
: coronary artery disease
CAPRIE
: Clopidogrel vs. Aspirin in Patients at Risk of Ischaemic Events
CASS
: Coronary Artery Surgery Study
CCB
: calcium channel blocker
CCS
: Canadian Cardiovascular Society
CFR
: coronary flow reserve
CHARISMA
: Clopidogrel for High Atherothrombotic Risk and Ischaemic Stabilization, Management and Avoidance
CI
: confidence interval
CKD
: chronic kidney disease
CKD-EPI
: Chronic Kidney Disease Epidemiology Collaboration
CMR
: cardiac magnetic resonance
CORONARY
: The CABG Off or On Pump Revascularization Study
COURAGE
: Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation
COX-1
: cyclooxygenase-1
COX-2
: cyclooxygenase-2
CPG
: Committee for Practice Guidelines
CT
: computed tomography
CTA
: computed tomography angiography
CV
: cardiovascular
CVD
: cardiovascular disease
CXR
: chest X-ray
CYP2C19*2
: cytochrome P450 2C19
CYP3A
: cytochrome P3A
CYP3A4
: cytochrome P450 3A4
CYP450
: cytochrome P450
DANAMI
: Danish trial in Acute Myocardial Infarction
DAPT
: dual antiplatelet therapy
DBP
: diastolic blood pressure
DECOPI
: Desobstruction Coronaire en Post-Infarctus
DES
: drug-eluting stents
DHP
: dihydropyridine
DSE
: dobutamine stress echocardiography
EACTS
: European Association for Cardiothoracic Surgery
EECP
: enhanced external counterpulsation
EMA
: European Medicines Agency
EASD
: European Association for the Study of Diabetes
ECG
: electrocardiogram
Echo
: echocardiogram
ED
: erectile dysfunction
EF
: ejection fraction
ESC
: European Society of Cardiology
EXCEL
: Evaluation of XIENCE PRIME or XIENCE V vs. Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization
FAME
: Fractional Flow Reserve vs. Angiography for Multivessel Evaluation
FDA
: Food & Drug Administration (USA)
FFR
: fractional flow reserve
FREEDOM
: Design of the Future Revascularization Evaluation in patients with Diabetes mellitus: Optimal management of Multivessel disease
GFR
: glomerular filtration rate
HbA1c
: glycated haemoglobin
HDL
: high density lipoprotein
HDL-C
: high density lipoprotein cholesterol
HR
: hazard ratio
HRT
: hormone replacement therapy
hs-CRP
: high-sensitivity C-reactive protein
HU
: Hounsfield units
ICA
: invasive coronary angiography
IMA
: internal mammary artery
IONA
: Impact Of Nicorandil in Angina
ISCHEMIA
: International Study of Comparative Health Effectiveness with Medical and Invasive Approaches
IVUS
: intravascular ultrasound
JSAP
: Japanese Stable Angina Pectoris
KATP
: ATP-sensitive potassium channels
LAD
: left anterior descending
LBBB
: left bundle branch block
LIMA
: Left internal mammary artery
LDL
: low density lipoprotein
LDL-C
: low density lipoprotein cholesterol
LM
: left main
LMS
: left main stem
LV
: left ventricular
LVEF
: left ventricular ejection fraction
LVH
: left ventricular hypertrophy
MACE
: major adverse cardiac events
MASS
: Medical, Angioplasty, or Surgery Study
MDRD
: Modification of Diet in Renal Disease
MERLIN
: Metabolic Efficiency with Ranolazine for Less Ischaemia in Non-ST-Elevation Acute Coronary Syndromes
MERLIN-TIMI 36
: Metabolic Efficiency with Ranolazine for Less Ischemia in Non-ST-Elevation Acute Coronary Syndromes: Thrombolysis In Myocardial Infarction
MET
: metabolic equivalents
MI
: myocardial infarction
MICRO-HOPE
: Microalbuminuria, cardiovascular and renal sub-study of the Heart Outcomes Prevention Evaluation study
MPI
: myocardial perfusion imaging
MRI
: magnetic resonance imaging
NO
: nitric oxide
NSAIDs
: non-steroidal anti-inflammatory drugs
NSTE-ACS
: non-ST-elevation acute coronary syndrome
NYHA
: New York Heart Association
OAT
: Occluded Artery Trial
OCT
: optical coherence tomography
OMT
: optimal medical therapy
PAR-1
: protease activated receptor type 1
PCI
: percutaneous coronary intervention
PDE5
: phosphodiesterase type 5
PES
: paclitaxel-eluting stents
PET
: positron emission tomography
PRECOMBAT
: Premier of Randomized Comparison of Bypass Surgery vs. Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary Artery Disease
PTP
: pre-test probability
PUFA
: polyunsaturated fatty acid
PVD
: peripheral vascular disease
QoL
: quality of life
RBBB
: right bundle branch block
REACH
: Reduction of Atherothrombosis for Continued Health
RITA-2
: Second Randomized Intervention Treatment of Angina
ROOBY
: Veterans Affairs Randomized On/Off Bypass
SAPT
: single antiplatelet therapy
SBP
: systolic blood pressure
SCAD
: stable coronary artery disease
SCORE
: Systematic Coronary Risk Evaluation
SCS
: spinal cord stimulation
SES
: sirolimus-eluting stents
SIMA
: single internal mammary artery
SPECT
: single photon emission computed tomography
STICH
: Surgical Treatment for Ischaemic Heart Failure
SWISSI II
: Swiss Interventional Study on Silent Ischaemia Type II
SYNTAX
: SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery
TC
: total cholesterol
TENS
: transcutaneous electrical neural stimulation
TERISA
: Type 2 Diabetes Evaluation of Ranolazine in Subjects With Chronic Stable Angina
TIME
: Trial of Invasive vs. Medical therapy
TIMI
: Thrombolysis In Myocardial Infarction
TMR
: transmyocardial laser revascularization
TOAT
: The Open Artery Trial
WOEST
: What is the Optimal antiplatElet and anticoagulant therapy in patients with oral anticoagulation and coronary StenTing
Guidelines summarize and evaluate all evidence available, at the time of the writing process, on a particular issue with the aim of assisting physicians in selecting the best management strategies for an individual patient with a given condition, taking into account the impact on outcome, as well …
3,879 citations
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TL;DR: The method is based on registering the individual volumes to a model free prediction of what each volume should look like, thereby enabling its use on high b-value data where the contrast is vastly different in different volumes.
2,431 citations
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TL;DR: The aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI, and provides an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements.
1,333 citations