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1.
Magn Reson Med ; 85(2): 855-867, 2021 02.
Article in English | MEDLINE | ID: mdl-32851676

ABSTRACT

PURPOSE: Respiratory motion in cardiovascular MRI presents a challenging problem with many potential solutions. Current approaches require breath-holds, apply retrospective image registration, or significantly increase scan time by respiratory gating. Myocardial T1 and T2 mapping techniques are particularly sensitive to motion as they require multiple source images to be accurately aligned prior to the estimation of tissue relaxation. We propose a patient-specific prospective motion correction (PROCO) strategy that corrects respiratory motion on the fly with the goal of reducing the spatial variation of myocardial parametric mapping techniques. METHODS: A rapid, patient-specific training scan was performed to characterize respiration-induced motion of the heart relative to a diaphragmatic navigator, and a parametric mapping pulse sequence utilized the resulting motion model to prospectively update the scan plane in real-time. Midventricular short-axis T1 and T2 maps were acquired under breath-hold or free-breathing conditions with and without PROCO in 7 healthy volunteers and 3 patients. T1 and T2 were measured in 6 segments and compared to reference standard breath-hold measurements using Bland-Altman analysis. RESULTS: PROCO significantly reduced the spatial variation of parametric maps acquired during free-breathing, producing limits of agreement of -47.16 to 30.98 ms (T1 ) and -1.35 to 4.02 ms (T2 ), compared to -67.77 to 74.34 ms (T1 ) and -2.21 to 5.62 ms (T2 ) for free-breathing acquisition without PROCO. CONCLUSION: Patient-specific respiratory PROCO method significantly reduced the spatial variation of myocardial T1 and T2 mapping, while allowing for 100% efficient free-breathing acquisitions.


Subject(s)
Image Interpretation, Computer-Assisted , Myocardium , Heart/diagnostic imaging , Humans , Magnetic Resonance Imaging , Motion , Prospective Studies , Reproducibility of Results , Retrospective Studies
3.
Magn Reson Med ; 81(6): 3662-3674, 2019 06.
Article in English | MEDLINE | ID: mdl-30761599

ABSTRACT

PURPOSE: To develop a patient-specific respiratory motion correction technique with true 100% acquisition efficiency. METHODS: A short training scan consisting of a series of single heartbeat images, each acquired with a preceding diaphragmatic navigator, was performed to fit a model relating the patient-specific 3D respiratory motion of the heart-to-diaphragm position. The resulting motion model was then used to update the imaging plane in real-time to correct for translational motion based on respiratory position provided by the navigator. The method was tested in a group of 11 volunteers with 5 separate free-breathing acquisitions: FB, no motion correction; FB-TF, free breathing with a linear tracking factor; Nav Gate, navigator gating; Nav Gate-TF, navigator gating with a tracking factor; and PROCO, prospective motion correction (proposed). Each acquisition lasted for 50 accepted heartbeats, where non-gated scans had a 100% acceptance rate, and gated scans accepted data only within a ±4 mm navigator window. Retrospective image registration was used to measure residual motion and determine the effectiveness of each method. RESULTS: PROCO reduced the range/RMSE of residual motion to 4.08 ± 1.4/0.90 ± 0.3 mm, compared to 10.78 ± 6.9/2.97 ± 2.2 mm for FB, 5.32 ± 2.92/1.24 ± 0.8 mm for FB-TF, 4.08 ± 1.6/0.93 ± 0.4 mm for Nav Gate, and 2.90 ± 1.0/0.63 ± 0.2 mm for Nav Gate-TF. Nav Gate and Nav Gate-TF reduced scan efficiency to 48.84 ± 9.31% and 54.54 ± 10.12%, respectively. CONCLUSION: PROCO successfully limited the residual motion in single-shot imaging to the level of traditional navigator gating while maintaining 100% acquisition efficiency.


Subject(s)
Heart/diagnostic imaging , Magnetic Resonance Imaging/methods , Patient-Specific Modeling , Respiratory-Gated Imaging Techniques/methods , Adult , Cardiac Imaging Techniques/methods , Female , Humans , Imaging, Three-Dimensional/methods , Male , Movement/physiology , Young Adult
6.
Endocr Pract ; 23(4): 479-497, 2017 Apr 02.
Article in English | MEDLINE | ID: mdl-28156151

ABSTRACT

OBJECTIVE: The development of these guidelines is mandated by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPGs). METHODS: Each Recommendation is based on a diligent review of the clinical evidence with transparent incorporation of subjective factors. RESULTS: The Executive Summary of this document contains 87 Recommendations of which 45 are Grade A (51.7%), 18 are Grade B (20.7%), 15 are Grade C (17.2%), and 9 (10.3%) are Grade D. These detailed, evidence-based recommendations allow for nuance-based clinical decision making that addresses multiple aspects of real-world medical care. The evidence base presented in the subsequent Appendix provides relevant supporting information for Executive Summary Recommendations. This update contains 695 citations of which 202 (29.1 %) are evidence level (EL) 1 (strong), 137 (19.7%) are EL 2 (intermediate), 119 (17.1%) are EL 3 (weak), and 237 (34.1%) are EL 4 (no clinical evidence). CONCLUSION: This CPG is a practical tool that endocrinologists, other healthcare professionals, regulatory bodies and health-related organizations can use to reduce the risks and consequences of dyslipidemia. It provides guidance on screening, risk assessment, and treatment recommendations for a range of patients with various lipid disorders. These recommendations emphasize the importance of treating low-density lipoprotein cholesterol (LDL-C) in some individuals to lower goals than previously recommended and support the measurement of coronary artery calcium scores and inflammatory markers to help stratify risk. Special consideration is given to patients with diabetes, familial hypercholesterolemia, women, and pediatric patients with dyslipidemia. Both clinical and cost-effectiveness data are provided to support treatment decisions. ABBREVIATIONS: A1C = hemoglobin A1C ACE = American College of Endocrinology ACS = acute coronary syndrome AHA = American Heart Association ASCVD = atherosclerotic cardiovascular disease ATP = Adult Treatment Panel apo = apolipoprotein BEL = best evidence level CKD = chronic kidney disease CPG = clinical practice guidelines CVA = cerebrovascular accident EL = evidence level FH = familial hypercholesterolemia HDL-C = high-density lipoprotein cholesterol HeFH = heterozygous familial hypercholesterolemia HIV = human immunodeficiency virus HoFH = homozygous familial hypercholesterolemia hsCRP = high-sensitivity C-reactive protein LDL-C = low-density lipoprotein cholesterol Lp-PLA2 = lipoprotein-associated phospholipase A2 MESA = Multi-Ethnic Study of Atherosclerosis MetS = metabolic syndrome MI = myocardial infarction NCEP = National Cholesterol Education Program PCOS = polycystic ovary syndrome PCSK9 = proprotein convertase subtilisin/kexin type 9 T1DM = type 1 diabetes mellitus T2DM = type 2 diabetes mellitus TG = triglycerides VLDL-C = very low-density lipoprotein cholesterol.


Subject(s)
Cardiovascular Diseases/prevention & control , Dyslipidemias/therapy , Endocrinology/standards , Primary Prevention/standards , Adult , Cardiovascular Diseases/economics , Child , Cost-Benefit Analysis , Diagnostic Techniques, Endocrine/economics , Diagnostic Techniques, Endocrine/standards , Dyslipidemias/diagnosis , Dyslipidemias/economics , Endocrinologists/organization & administration , Endocrinologists/standards , Endocrinology/organization & administration , Female , Humans , Mass Screening/economics , Mass Screening/methods , Mass Screening/standards , Primary Prevention/economics , Primary Prevention/methods , Societies, Medical/organization & administration , United States
9.
Endocr Pract ; 21(12): 1403-14, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26642101

ABSTRACT

This document represents the official position of the American Association of Clinical Endocrinologists and the American College of Endocrinology. Where there were no randomized controlled trials or specific U.S. FDA labeling for issues in clinical practice, the participating clinical experts utilized their judgment and experience. Every effort was made to achieve consensus among the committee members. Position statements are meant to provide guidance, but they are not to be considered prescriptive for any individual patient and cannot replace the judgment of a clinician.


Subject(s)
Algorithms , Diabetes Mellitus, Type 2/therapy , Blood Glucose/metabolism , Blood Pressure , Consensus , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/physiopathology , Humans , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Lipid Metabolism/drug effects , Obesity/complications , Obesity/metabolism , Obesity/physiopathology , Obesity/therapy , Prediabetic State/metabolism , Prediabetic State/pathology , Prediabetic State/physiopathology , Prediabetic State/therapy , United States
16.
Endocrinol Metab Clin North Am ; 36 Suppl 1: 33-44, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17881330

ABSTRACT

Weight gain can be a significant barrier to the treatment of diabetes. Insulin detemir is a basal insulin analog that can help patients move safely toward glycemic targets with less weight gain. This review discusses the potential adverse effects of, and hypothesis for, weight gain resulting from intensive insulin management of diabetes. In addition, an assessment of all weight change data from clinical trials and observational studies involving insulin detemir are presented. Finally, we discuss how the ability of insulin detemir to closely mimic endogenous insulin secretion leads to more predictable glycemic control with reduced weight gain and provides patients with a more acceptable method of achieving glycemic control.


Subject(s)
Body Weight/drug effects , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Insulin/analogs & derivatives , Humans , Insulin/therapeutic use , Insulin Detemir , Insulin, Long-Acting
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