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Jennifer Keegan

Other affiliations: Imperial College London
Bio: Jennifer Keegan is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Coronary arteries & Heart failure. The author has an hindex of 40, co-authored 160 publications receiving 5865 citations. Previous affiliations of Jennifer Keegan include Imperial College London.


Papers
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Journal ArticleDOI
TL;DR: This paper provides a deep learning-based strategy for reconstruction of CS-MRI, and bridges a substantial gap between conventional non-learning methods working only on data from a single image, and prior knowledge from large training data sets.
Abstract: Compressed sensing magnetic resonance imaging (CS-MRI) enables fast acquisition, which is highly desirable for numerous clinical applications. This can not only reduce the scanning cost and ease patient burden, but also potentially reduce motion artefacts and the effect of contrast washout, thus yielding better image quality. Different from parallel imaging-based fast MRI, which utilizes multiple coils to simultaneously receive MR signals, CS-MRI breaks the Nyquist–Shannon sampling barrier to reconstruct MRI images with much less required raw data. This paper provides a deep learning-based strategy for reconstruction of CS-MRI, and bridges a substantial gap between conventional non-learning methods working only on data from a single image, and prior knowledge from large training data sets. In particular, a novel conditional Generative Adversarial Networks-based model (DAGAN)-based model is proposed to reconstruct CS-MRI. In our DAGAN architecture, we have designed a refinement learning method to stabilize our U-Net based generator, which provides an end-to-end network to reduce aliasing artefacts. To better preserve texture and edges in the reconstruction, we have coupled the adversarial loss with an innovative content loss. In addition, we incorporate frequency-domain information to enforce similarity in both the image and frequency domains. We have performed comprehensive comparison studies with both conventional CS-MRI reconstruction methods and newly investigated deep learning approaches. Compared with these methods, our DAGAN method provides superior reconstruction with preserved perceptual image details. Furthermore, each image is reconstructed in about 5 ms, which is suitable for real-time processing.

835 citations

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TL;DR: The review includes phase-contrast applications in cardiac function, heart valves, congenital heart diseases, major blood vessels, coronary arteries and myocardial wall velocity.
Abstract: A review of cardiovascular clinical and research applications of MRI phase-contrast velocity imaging, also known as velocity mapping or flow imaging. Phase-contrast basic principles, advantages, limitations, common pitfalls and artefacts are described. It can measure many different aspects of the complicated blood flow in the heart and vessels: volume flow (cardiac output, shunt, valve regurgitation), peak blood velocity (for stenosis), patterns and timings of velocity waveforms and flow distributions within heart chambers (abnormal ventricular function) and vessels (pulse-wave velocity, vessel wall disease). The review includes phase-contrast applications in cardiac function, heart valves, congenital heart diseases, major blood vessels, coronary arteries and myocardial wall velocity.

326 citations

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TL;DR: This circadian distribution of ischaemic episodes and the observed changes with treatment resemble the reported circadian variation of acute myocardial infarction and sudden death.

321 citations

Journal ArticleDOI
TL;DR: This work presents the methodologies and evaluation results for the WHS algorithms selected from the submissions to the Multi-Modality Whole Heart Segmentation (MM-WHS) challenge, in conjunction with MICCAI 2017.

216 citations

Journal ArticleDOI
TL;DR: For the assessment of anomalous coronary artery anatomy in patients with congenital heart disease, the use of the combination of MRCA with x-ray coronary angiography improves the definition of the proximal coronary artery course.
Abstract: Background—There is a high incidence of anomalous coronary arteries in subjects with congenital heart disease. These abnormalities can be responsible for myocardial ischemia and sudden death or be ...

205 citations


Cited by
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Journal ArticleDOI
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

Journal ArticleDOI
TL;DR: Left ventricular end-diastolic and end-systolic volume and ejection fraction data provide support for the beneficial effects of therapeutic agents such as angiotensin-converting enzyme (ACE) inhibitors and beta-adrenergic blocking agents on the remodeling process.

2,215 citations

Reference EntryDOI
15 Oct 2004

2,118 citations

Journal ArticleDOI
TL;DR: The Clinical Efficacy Assessment Subcommittee of the American College of Physicians–American Society of Internal Medicine acknowledges the scientific validity of this product as a background paper and as a review that captures the levels of evidence in the management of patients with chronic stable angina as of November 17, 2002.
Abstract: The Clinical Efficacy Assessment Subcommittee of the American College of Physicians–American Society of Internal Medicine acknowledges the scientific validity of this product as a background paper and as a review that captures the levels of evidence in the management of patients with chronic stable angina as of November 17, 2002 The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines regularly reviews existing guidelines to determine when an update or a full revision is needed This process gives priority to areas in which major changes in text, and particularly recommendations, are merited on the basis of new understanding or evidence Minor changes in verbiage and references are discouraged The ACC/AHA/American College of Physicians–American Society of Internal Medicine (ACP-ASIM) Guidelines for the Management of Patients With Chronic Stable Angina, which were published in June 1999, have now been updated The full-text guideline incorporating the updated material is available on the Internet (wwwaccorg or wwwamericanheartorg) in both a track-changes version showing the changes in the 1999 guideline in strike-out (deleted text) and highlighting …

1,796 citations