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Stein EJ, Perkons NR, Wildenberg JC, Iyer SK, Hunt SJ, Nadolski GJ, Witschey WR, Gade TP. MR Imaging Enables Real-Time Monitoring of In Vitro Electrolytic Ablation of Hepatocellular Carcinoma. J Vasc Interv Radiol 2019; 31:352-361. [PMID: 31748127 DOI: 10.1016/j.jvir.2019.07.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/12/2019] [Accepted: 07/20/2019] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To evaluate the capability of T2-weighted magnetic resonance (MR) imaging to monitor electrolytic ablation-induced cell death in real time. MATERIALS AND METHODS Agarose phantoms arranged as an electrolytic cell were exposed to varying quantities of electric charge under constant current to create a pH series. The pH phantoms were subjected to T2-weighted imaging with region of interest quantitation of the acquired signal intensity. Subsequently, hepatocellular carcinoma (HCC) cells encapsulated in an agarose gel matrix were subjected to 10 V of electrolytic ablation for variable lengths of time with and without concurrent T2-weighted MR imaging. Cellular death was confirmed by a fluorescent reporter. Finally, to confirm that real-time MR images corresponded to ablation zones, 10 V electrolytic ablations were performed followed by the addition of pH-neutralizing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer. RESULTS Analysis of MR imaging from agarose gel pH phantoms demonstrated a relationship between signal intensity and pH at the anodes and cathodes. The steep negative phase of the anode model (pH < 3.55) and global minimum of the cathode model (pH ≈ 11.62) closely approximated established cytotoxic pH levels. T2-weighted MR imaging demonstrated a strong correlation of ablation zones with regions of HCC cell death (r = 0.986; R2 = 0.916; P < .0001). The addition of HEPES buffer to the hydrogel resulted in complete obliteration of MR imaging-observed ablation zones, confirming that change in pH directly caused the observed signal intensity attenuation of the ablation zone. CONCLUSIONS T2-weighted MR imaging enabled the real-time detection of electrolytic ablation zones, demonstrating a strong correlation with histologic cell death.
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Bagga P, Hariharan H, Wilson NE, Beer JC, Shinohara RT, Elliott MA, Baur JA, Marincola FM, Witschey WR, Haris M, Detre JA, Reddy R. Single-Voxel 1 H MR spectroscopy of cerebral nicotinamide adenine dinucleotide (NAD + ) in humans at 7T using a 32-channel volume coil. Magn Reson Med 2019; 83:806-814. [PMID: 31502710 DOI: 10.1002/mrm.27971] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/15/2019] [Accepted: 08/06/2019] [Indexed: 12/12/2022]
Abstract
PURPOSE Reliable monitoring of tissue nicotinamide adenine dinucleotide (NAD+ ) concentration may provide insights on its roles in normal and pathological aging. In the present study, we report a 1 H MRS pulse sequence for the in vivo, localized 1 H MRS detection of NAD+ from the human brain. METHODS Studies were carried out on a 7T Siemens MRI scanner using a 32-channel product volume coil. The pulse sequence consisted of a spectrally selective low bandwidth E-BURP-1 90° pulse. PRESS localization was achieved using optimized Shinnar-Le Roux 180° pulses and overlapping gradients were used to minimize the TE. The reproducibility of NAD+ quantification was measured in 11 healthy volunteers. The association of cerebral NAD+ with age was assessed in 16 healthy subjects 26-78 years old. RESULTS Spectra acquired from a voxel placed in subjects' occipital lobe consisted of downfield peaks from the H2 , H4 , and H6 protons of the nicotinamide moiety of NAD+ between 8.9-9.35 ppm. The mean ± SD within-session and between-session coefficients of variation were found to be 6.14 ± 2.03% and 6.09 ± 3.20%, respectively. In healthy volunteers, an age-dependent decline of the NAD+ levels in the brain was also observed (β = -1.24 μM/y, SE = 0.21, P < 0.001). CONCLUSION We demonstrated the feasibility and robustness of a newly developed 1 H MRS technique to measure localized cerebral NAD+ at 7T MRI using a commercially available RF head coil. This technique may be further applied to detect and quantify NAD+ from different regions of the brain as well as from other tissues.
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Rodriguez I, Philips BH, Miedel EL, Bright LA, LaTourette PC, Carty AJ, Witschey WR, Gorman RC, Gorman JH, Marx JO. Hydromorphone-induced Neurostimulation in a Yorkshire Swine ( Sus scrofa) after Myocardial Infarction Surgery. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2019; 58:601-605. [PMID: 31451134 PMCID: PMC6774467 DOI: 10.30802/aalas-jaalas-18-000095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/04/2018] [Accepted: 10/24/2018] [Indexed: 11/05/2022]
Abstract
Opiates play an important role in the control of pain associated with thoracotomy in both people and animals. However, key side effects, including sedation and respiratory depression, could limit the use of opiates in animals that are lethargic due to cardiac disease. In addition, a rare side effect-neuroexcitation resulting in pathologic behavioral changes (seizures, mania, muscle fasciculation)-after the administration of morphine or hydromorphone is well-documented in many species. In pigs, however, these drugs have been shown to stimulate an increase in normal activity. In the case presented, we describe a Yorkshire-cross pig which, after myocardial infarction surgery, went from nonresponsive to alert, responsive, and eating within 30 min of an injection of hydromorphone. This pig was not demonstrating any signs associated with pain at this time, suggesting that the positive response was due to neural stimulation. This case report is the first to describe the use of hydromorphone-a potent, pure μ opiate agonist-for its neurostimulatory effect in pigs with experimentally-induced cardiac disease.
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Kamesh Iyer S, Moon B, Hwuang E, Han Y, Solomon M, Litt H, Witschey WR. Accelerated free-breathing 3D T1ρ cardiovascular magnetic resonance using multicoil compressed sensing. J Cardiovasc Magn Reson 2019; 21:5. [PMID: 30626437 PMCID: PMC6327532 DOI: 10.1186/s12968-018-0507-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 11/13/2018] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Endogenous contrast T1ρ cardiovascular magnetic resonance (CMR) can detect scar or infiltrative fibrosis in patients with ischemic or non-ischemic cardiomyopathy. Existing 2D T1ρ techniques have limited spatial coverage or require multiple breath-holds. The purpose of this project was to develop an accelerated, free-breathing 3D T1ρ mapping sequence with whole left ventricle coverage using a multicoil, compressed sensing (CS) reconstruction technique for rapid reconstruction of undersampled k-space data. METHODS We developed a cardiac- and respiratory-gated, free-breathing 3D T1ρ sequence and acquired data using a variable-density k-space sampling pattern (A = 3). The effect of the transient magnetization trajectory, incomplete recovery of magnetization between T1ρ-preparations (heart rate dependence), and k-space sampling pattern on T1ρ relaxation time error and edge blurring was analyzed using Bloch simulations for normal and chronically infarcted myocardium. Sequence accuracy and repeatability was evaluated using MnCl2 phantoms with different T1ρ relaxation times and compared to 2D measurements. We further assessed accuracy and repeatability in healthy subjects and compared these results to 2D breath-held measurements. RESULTS The error in T1ρ due to incomplete recovery of magnetization between T1ρ-preparations was T1ρhealthy = 6.1% and T1ρinfarct = 10.8% at 60 bpm and T1ρhealthy = 13.2% and T1ρinfarct = 19.6% at 90 bpm. At a heart rate of 60 bpm, error from the combined effects of readout-dependent magnetization transients, k-space undersampling and reordering was T1ρhealthy = 12.6% and T1ρinfarct = 5.8%. CS reconstructions had improved edge sharpness (blur metric = 0.15) compared to inverse Fourier transform reconstructions (blur metric = 0.48). There was strong agreement between the mean T1ρ estimated from the 2D and accelerated 3D data (R2 = 0.99; P < 0.05) acquired on the MnCl2 phantoms. The mean R1ρ estimated from the accelerated 3D sequence was highly correlated with MnCl2 concentration (R2 = 0.99; P < 0.05). 3D T1ρ acquisitions were successful in all human subjects. There was no significant bias between undersampled 3D T1ρ and breath-held 2D T1ρ (mean bias = 0.87) and the measurements had good repeatability (COV2D = 6.4% and COV3D = 7.1%). CONCLUSIONS This is the first report of an accelerated, free-breathing 3D T1ρ mapping of the left ventricle. This technique may improve non-contrast myocardial tissue characterization in patients with heart disease in a scan time appropriate for patients.
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Schwartz N, Hwuang E, Rodriguez-Soto A, Wehrli F, Vidorreta M, Moon BF, Kochar K, Parameshwaran S, Koelper NC, Sammel MD, Tisdall MD, Detre J, Witschey WR. 1050: Cross-modality, in-vivo validation of 4D-Flow MRI evaluation of uterine artery blood flow in human pregnancy. Am J Obstet Gynecol 2019. [DOI: 10.1016/j.ajog.2018.11.1074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Al-Badri A, Hashmath Z, Oldland GH, Miller R, Javaid K, Syed AA, Ansari B, Gaddam S, Witschey WR, Akers SR, Chirinos JA. Poor Glycemic Control Is Associated With Increased Extracellular Volume Fraction in Diabetes. Diabetes Care 2018; 41:2019-2025. [PMID: 30002196 PMCID: PMC6105326 DOI: 10.2337/dc18-0324] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/18/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE We assessed whether poor glycemic control is associated with an increase in myocardial fibrosis among adults with diabetes. RESEARCH DESIGN AND METHODS We studied 47 adults with type 2 diabetes and stratified them into three groups according to their hemoglobin A1c (HbA1c) level: <6.5% (group 1; n = 12), 6.5-7.5% (group 2; n = 20), and >7.5% (group 3; n = 15). Left ventricular (LV) mass was assessed using cardiac MRI. The extracellular volume fraction (ECVF), an index of myocardial fibrosis, was measured by using myocardial T1 mapping before and after the administration of a gadolinium-based contrast agent. RESULTS Mean HbA1c was 5.84 ± 0.16%, 6.89 ± 0.14%, and 8.57 ± 0.2% in groups 1, 2, and 3, respectively. LV mass was not significantly different between the groups. The myocardial ECVF was significantly greater in groups 2 (mean 27.6% [95% CI 24.8-30.3]) and 3 (27.6% [24.4-30.8]) than in group 1 (21.1% [17.5-24.7]; P = 0.015). After adjusting for age, sex, BMI, blood pressure, and estimated glomerular filtration rate, the myocardial ECVF was significantly greater in groups 2 (27.4% [24.4-30.4]) and 3 (28% [24.5-31.5]) than in group 1 (20.9% [17.1-24.6]; P = 0.0156, ANCOVA). CONCLUSIONS An increased myocardial ECVF, suggesting myocardial fibrosis, is independently associated with poor glycemic control among adults with diabetes. Further research should assess whether tight glycemic control can revert fibrosis to healthy myocardium or ameliorate it and its adverse clinical consequences.
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Zamani P, Akers S, Soto-Calderon H, Beraun M, Koppula MR, Varakantam S, Rawat D, Shiva-Kumar P, Haines PG, Chittams J, Townsend RR, Witschey WR, Segers P, Chirinos JA. Isosorbide Dinitrate, With or Without Hydralazine, Does Not Reduce Wave Reflections, Left Ventricular Hypertrophy, or Myocardial Fibrosis in Patients With Heart Failure With Preserved Ejection Fraction. J Am Heart Assoc 2017; 6:JAHA.116.004262. [PMID: 28219917 PMCID: PMC5523746 DOI: 10.1161/jaha.116.004262] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Background Wave reflections, which are increased in patients with heart failure with preserved ejection fraction, impair diastolic function and promote pathologic myocardial remodeling. Organic nitrates reduce wave reflections acutely, but whether this is sustained chronically or affected by hydralazine coadministration is unknown. Methods and Results We randomized 44 patients with heart failure with preserved ejection fraction in a double‐blinded fashion to isosorbide dinitrate (ISDN; n=13), ISDN+hydralazine (ISDN+hydral; n=15), or placebo (n=16) for 6 months. The primary end point was the change in reflection magnitude (RM; assessed with arterial tonometry and Doppler echocardiography). Secondary end points included change in left ventricular mass and fibrosis, measured with cardiac magnetic resonance imaging, and the 6‐minute walk distance. ISDN reduced aortic characteristic impedance (mean baseline=0.15 [95% CI, 0.14–0.17], 3 months=0.11 [95% CI, 0.10–0.13], 6 months=0.10 [95% CI, 0.08–0.12] mm Hg/mL per second; P=0.003) and forward wave amplitude (Pf, mean baseline=54.8 [95% CI, 47.6–62.0], 3 months=42.2 [95% CI, 33.2–51.3]; 6 months=37.0 [95% CI, 27.2–46.8] mm Hg, P=0.04), but had no effect on RM (P=0.64), left ventricular mass (P=0.33), or fibrosis (P=0.63). ISDN+hydral increased RM (mean baseline=0.39 [95% CI, 0.35–0.43]; 3 months=0.31 [95% CI, 0.25–0.36]; 6 months=0.44 [95% CI, 0.37–0.51], P=0.03), reduced 6‐minute walk distance (mean baseline=343.3 [95% CI, 319.2–367.4]; 6 months=277.0 [95% CI, 242.7–311.4] meters, P=0.022), and increased native myocardial T1 (mean baseline=1016.2 [95% CI, 1002.7–1029.7]; 6 months=1054.5 [95% CI, 1036.5–1072.3], P=0.021). A high proportion of patients experienced adverse events with active therapy (ISDN=61.5%, ISDN+hydral=60.0%; placebo=12.5%; P=0.007). Conclusions ISDN, with or without hydralazine, does not exert beneficial effects on RM, left ventricular remodeling, or submaximal exercise and is poorly tolerated. ISDN+hydral appears to have deleterious effects on RM, myocardial remodeling, and submaximal exercise. Our findings do not support the routine use of these vasodilators in patients with heart failure with preserved ejection fraction. Clinical Trial Registration URL: www.clinicaltrials.gov. Unique identifier: NCT01516346.
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Madden M, Mohammed S, Contijoch F, Pilla JJ, Gorman JH, Han Y, Gorman RC, Witschey WR. Assessment of T1rho relaxation times after reperfused myocardial infarction. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032068 DOI: 10.1186/1532-429x-18-s1-w13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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Shahid M, Solomon J, Contijoch F, Avants B, Yushkevich P, Pilla JJ, Han Y, Witschey WR. Alterations in ectopic myocardial contraction assessed using real-time MRI. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032133 DOI: 10.1186/1532-429x-18-s1-p55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Contijoch F, Berisha S, Gorman JH, Gorman RC, Witschey WR, Han Y. Impact of Respiration on LV Volume and Function Using rt-MRI. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032536 DOI: 10.1186/1532-429x-18-s1-p329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Gralewski K, Witschey WR, Pollock SD, Whitehead KK. Continuity equation-derived valve area using CMR phase-contrast provides flow-independent assessment of valve stenosis. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032262 DOI: 10.1186/1532-429x-18-s1-p158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Witschey WR, Wang J, Litt H, Han Y. Relaxation time mapping technique development improves disease detectability. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032703 DOI: 10.1186/1532-429x-18-s1-w37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Contijoch F, Rears H, Rogers K, Kellman P, Gorman JH, Gorman RC, Witschey WR, Han Y. Beat to beat volumetric analysis in arrhythmia using real time CMR. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328715 DOI: 10.1186/1532-429x-17-s1-o37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Contijoch F, Han Y, Hansen M, Kellman P, Gualtieri E, Elliott M, Berisha S, Pilla JJ, Gorman RC, Witschey WR. Continuous adaptive radial sampling of k-space from real-time physiologic feedback in MRI. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328682 DOI: 10.1186/1532-429x-17-s1-p37] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Chhour P, Gallo N, Cheheltani R, Williams D, Al-Zaki A, Paik T, Nichol JL, Tian Z, Naha PC, Witschey WR, Allcock HR, Murray CB, Tsourkas A, Cormode DP. Nanodisco balls: control over surface versus core loading of diagnostically active nanocrystals into polymer nanoparticles. ACS NANO 2014; 8:9143-53. [PMID: 25188401 PMCID: PMC4174093 DOI: 10.1021/nn502730q] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 09/04/2014] [Indexed: 05/16/2023]
Abstract
Nanoparticles of complex architectures can have unique properties. Self-assembly of spherical nanocrystals is a high yielding route to such systems. In this study, we report the self-assembly of a polymer and nanocrystals into aggregates, where the location of the nanocrystals can be controlled to be either at the surface or in the core. These nanospheres, when surface decorated with nanocrystals, resemble disco balls, thus the term nanodisco balls. We studied the mechanism of this surface loading phenomenon and found it to be Ca(2+) dependent. We also investigated whether excess phospholipids could prevent nanocrystal adherence. We found surface loading to occur with a variety of nanocrystal types including iron oxide nanoparticles, quantum dots, and nanophosphors, as well as sizes (10-30 nm) and shapes. Additionally, surface loading occurred over a range of polymer molecular weights (∼30-3000 kDa) and phospholipid carbon tail length. We also show that nanocrystals remain diagnostically active after loading onto the polymer nanospheres, i.e., providing contrast in the case of magnetic resonance imaging for iron oxide nanoparticles and fluorescence for quantum dots. Last, we demonstrated that a fluorescently labeled protein model drug can be delivered by surface loaded nanospheres. We present a platform for contrast media delivery, with the unusual feature that the payload can be controllably localized to the core or the surface.
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Han Q, Han Y, Gorman RC, Witschey WR. The influence of static and RF field heterogeneity on T1rho cardiovascular MRI. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044013 DOI: 10.1186/1532-429x-16-s1-p70] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Contijoch F, Rogers K, Witschey WR, Gorman RC, Han Y. Left ventricular dyssynchrony can be observed via cine CMR with use of aortic valve timing. J Cardiovasc Magn Reson 2014. [PMCID: PMC4045839 DOI: 10.1186/1532-429x-16-s1-p243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Witschey WR, Contijoch F, McGarvey JR, Ferrari VA, Hansen M, Chirinos J, Yushkevich P, Gorman JH, Gorman RC, Pilla JJ. The Frank-Starling relationship of the heart revealed in a large animal study utilizing real-time undersampled radial MRI at variable inotropic state and heart rate. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044193 DOI: 10.1186/1532-429x-16-s1-p57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Contijoch F, Rogers K, Witschey WR, Gorman RC, Han Y. The spatial and temporal fidelity in real-time MRI in patients with sinus rhythm and arrhythmias. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042225 DOI: 10.1186/1532-429x-16-s1-o11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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Zhang D, McGarvey JR, Lee M, Takebayashi S, Aoki C, Dillard C, Contijoch F, Zsido G, Han Q, Han Y, Pilla JJ, Gorman JH, Witschey WR, Gorman RC. Mitral valve stenosis and left ventricular hemodynamic alterations after mitral valve repair. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044525 DOI: 10.1186/1532-429x-16-s1-o70] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Han Q, Witschey WR, Arkles J, Barker AJ, Han Y. RV work efficiency is greatly reduced in patients with pulmonary arterial hypertension as evidenced by 4D flow cardiac MRI. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044892 DOI: 10.1186/1532-429x-16-s1-p235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Contijoch F, Rogers K, Avants B, Yushkevich P, Hoshmand V, Gorman RC, Han Y, Witschey WR. Quantification of left ventricular deformation fields from undersampled radial, real-time cardiac MRI. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042533 DOI: 10.1186/1532-429x-16-s1-p366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Contijoch F, Rogers K, Witschey WR, Gorman RC, Han Y. Aortic valve timing is critical for accurate estimation of MRI-derived ejection fraction. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042330 DOI: 10.1186/1532-429x-16-s1-p327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Contijoch F, Witschey WR, McGarvey JR, Levack MM, Ferrari VA, Kondo N, Takebayashi S, Shimaoka T, Aoki C, Zsido GA, Gorman JH, Gorman RC, Pilla JJ. Real time MRI of border zone end-systolic regional work. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559805 DOI: 10.1186/1532-429x-15-s1-p191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Levack MM, Witschey WR, McGarvey JR, Kondo N, Zsido GA, Gorman JH, Pilla JJ, Gorman RC. Mitral leaflet dynamics in ischemic mitral regurgitation using high resolution MRI. J Cardiovasc Magn Reson 2012. [PMCID: PMC3305775 DOI: 10.1186/1532-429x-14-s1-w57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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