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1.
Medicine (Baltimore) ; 101(2): e28498, 2022 Jan 14.
Article in English | MEDLINE | ID: mdl-35029202

ABSTRACT

BACKGROUND: Insomnia in perimenopausal women has a negative impact on quality of life and increases health care costs. With the increasing incidence of the disease, Tuina has been accepted by perimenopausal women. The purpose of this study is to explore the effectiveness and safety of Tuina for perimenopausal insomnia. METHODS: We will search 9 electronic databases: Chinese Biomedical Literature Database, Cochrane Library, China National Knowledge Infrastructure, EMBASE, MEDLINE, Web of Science, PubMed, Wan fang, Chinese Scientific Journal Database, and 1 clinical trials register platform: WHO International Clinical Trials Registry Platform. All relevant randomized controlled trial using Tuina for perimenopausal insomnia will be included. Two reviewers will independently screen date, and meta-analysis will be performed with RevMan (V5.3.5) software. RESULTS: This study will provide an evidence of Tuina for perimenopausal insomnia. CONCLUSION: This study will provide a reliable evidence for the evaluation of the efficacy and side effects of Tuina in the treatment of perimenopausal insomnia. PROSPERO REGISTRATION NUMBER: CRD42021259017. ETHICS AND DISSEMINATION: This systematics review will evaluate the efficacy and safety of tuina in the treatment of perimenopausal insomnia. Since all the data included were published, the systematic review did not require ethical approval.


Subject(s)
Massage , Sleep Initiation and Maintenance Disorders , Female , Humans , Meta-Analysis as Topic , Perimenopause , Quality of Life , Randomized Controlled Trials as Topic , Research Design , Sleep Initiation and Maintenance Disorders/therapy , Systematic Reviews as Topic , Treatment Outcome
2.
BMC Med Imaging ; 17(1): 5, 2017 01 10.
Article in English | MEDLINE | ID: mdl-28068946

ABSTRACT

BACKGROUND: To systematically investigate the relationship between CT morphological features and the presence of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC). METHODS: All studies about the CT morphological features of NSCLC with EGFR mutations published between January 1, 2000 and March 15, 2015 were searched in the PubMed and EMBASE databases. Qualified studies were selected according to inclusion criteria. The frequency of EGFR mutations and CT features of ground-glass opacity (GGO) content, tumor size, cavitation, air-bronchogram, lobulation, and spiculation were extracted. The relationship between EGFR mutations and each of these CT features was tested based upon the weighted mean difference or inverse variance in the form of an odds ratio at a 95% confidence interval using Forest Plots. The publication bias was examined using Egger's test. RESULTS: A total of 13 studies, consisting of 2146 NSCLC patients, were included, and 51.12% (1097/2146) of patients had EGFR mutations. The EGFR mutations were present in NSCLC with part-solid GGO in contrast to nonsolid GGO (OR = 0.49, 95% CI = 0.25-0.96, P = 0.04). Other CT features such as tumor size, cavitation, air-bronchogram, lobulation and spiculation did not demonstrate statistically significant correlation with EGFR mutations individually (P = 0.91; 0.67; 0.12; 0.45; and 0.36, respectively). No publication bias among the selected studies was noted in this meta-analysis (Egger's tests, P > 0.05 for all). CONCLUSION: This meta-analysis demonstrated that NSCLC with CT morphological features of part-solid GGO tended to be EGFR mutated, which might provide an important clue for the correct selection of patients treated with molecular targeted therapies.


Subject(s)
Carcinoma, Non-Small-Cell Lung/diagnostic imaging , ErbB Receptors/genetics , Lung Neoplasms/diagnostic imaging , Tomography, X-Ray Computed/methods , Carcinoma, Non-Small-Cell Lung/genetics , Humans , Lung Neoplasms/genetics , Mutation , Mutation Rate , Neoplasm Staging
3.
Heart Rhythm ; 12(4): 802-8, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25583153

ABSTRACT

BACKGROUND: The majority of patients receiving implantable cardioverter-defibrillator (ICD) implantation under current guidelines never develop sustained ventricular arrhythmia; therefore, better markers of risk for sustained ventricular tachycardia and/or ventricular fibrillation are needed. OBJECTIVE: The purpose of this study was to identify cardiac magnetic resonance arrhythmic risk predictors of ischemic cardiomyopathy before ICD implantation. METHODS: Forty-three subjects (mean age, 64.5 ± 11.9 years) with previous myocardial infarction who were referred for ICD implantation were evaluated by cardiac magnetic resonance imaging (MRI). The MRI protocol included left ventricular functional parameter assessment using steady-state free precession and late gadolinium enhancement MRI using inversion recovery fast gradient echo. Left ventricular functional parameters were measured using cardiac magnetic resonance software. Subjects were followed up for 6-46 months, and the events of appropriate ICD treatments (shocks and antitachycardia pacing) were recorded. RESULTS: Twenty-eight patients experienced 46 spontaneous episodes during a median follow-up duration of 30 months. The total myocardial infarct (MI) size (18.05 ± 11.44 g vs 38.83 ± 19.87 g; P = .0006), MI core (11.63 ± 7.14 g vs 24.12 ± 12.73 g; P = .0002), and infarct gray zone (6.43 ± 4.64 g vs 14.71 ± 7.65 g; P = .0004) were significantly larger in subjects who received appropriate ICD therapy than in those who did not experience an episode of ventricular tachycardia and/or ventricular fibrillation. Multivariate regression analyses for the infarct gray zone and MI core adjusted for New York Heart Association class, diabetes, and etiology (primary or secondary prevention) revealed that the gray zone and MI core were predictors of appropriate ICD therapies (P = .0018 and P = .007, respectively). CONCLUSION: The extent of MI scar may predict which patients would benefit most from ICD implantation.


Subject(s)
Cardiomyopathies , Cicatrix , Death, Sudden, Cardiac/prevention & control , Defibrillators, Implantable , Myocardial Infarction/complications , Myocardium/pathology , Tachycardia, Ventricular , Aged , Canada , Cardiomyopathies/diagnosis , Cardiomyopathies/etiology , Cardiomyopathies/pathology , Cardiomyopathies/therapy , Cicatrix/diagnosis , Cicatrix/etiology , Female , Follow-Up Studies , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging, Cine/methods , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Risk Assessment/methods , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/prevention & control
4.
J Magn Reson Imaging ; 39(3): 609-16, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23720077

ABSTRACT

PURPOSE: To investigate the potentially improved detection and quantification of cardiac involvement using novel late-gadolinium-enhancement (LGE) cardiac magnetic resonance imaging (MRI) and quantitative T2 measurement to achieve better myocardial tissue characterization in systemic sarcoidosis. MATERIALS AND METHODS: Twenty-eight patients with systemic sarcoidosis underwent a cardiac magnetic resonance imaging (CMR) study on a 1.5T system. Precontrast CMR included left ventricular (LV) and right ventricular (RV) function and quantitative T2 measurement. Postcontrast LGE-MRI included inversion-recovery fast-gradient-echo (IR-FGRE) and multicontrast late-enhancement imaging (MCLE). RESULTS: LV functional parameters were normal in all patients (LVEF=61.2±8.5%) including with cardiac involvement (LVEF=59.4±12.1%) and without (LVEF=61.7±7.5%) while the average RV function was comparatively decreased (RVEF=48.0±6.6%, P<0.0001). 21.4% of patients had cardiac involvement showing patchy or multiple focal hyperenhancement patterns in LV free wall, papillary muscles (PM), or interventricular septum. In two cases with PM involvement, the PM abnormal LGE foci were only observed on MCLE. For precontrast T2 measurements, a significantly decreased T2 measurement was observed in regions demonstrating LGE, compared to the LGE-negative group (focal LGE-positive regions vs. negative: 40.0±2.4 msec vs. 53.0±2.6 msec, P<0.0001). CONCLUSION: LGE-MRI can identify cardiac involvement in systemic sarcoidosis. MCLE might be more sensitive at detecting subtle myocardial lesion. The decreased T2 observed in cardiac sarcoid may reflect its inactive phase, thus might provide a noninvasive method for monitoring disease activity or therapy.


Subject(s)
Cardiomyopathies/diagnosis , Gadolinium DTPA , Image Enhancement , Magnetic Resonance Imaging, Cine/methods , Sarcoidosis/diagnosis , Adult , Cardiomyopathies/pathology , Cohort Studies , Female , Heart Function Tests , Humans , Male , Middle Aged , Prospective Studies , Sarcoidosis/pathology , Sensitivity and Specificity , Severity of Illness Index
5.
J Cardiovasc Magn Reson ; 15: 57, 2013 Jun 26.
Article in English | MEDLINE | ID: mdl-23803259

ABSTRACT

BACKGROUND: Myocardial infarct heterogeneity indices including peri-infarct gray zone are predictors for spontaneous ventricular arrhythmias events after ICD implantation in patients with ischemic heart disease. In this study we hypothesize that the extent of peri-infarct gray zone and papillary muscle infarct scores determined by a new multi-contrast late enhancement (MCLE) method may predict appropriate ICD therapy in patients with ischemic heart disease. METHODS: The cardiovascular magnetic resonance (CMR) protocol included LV functional parameter assessment and late gadolinium enhancement (LGE) CMR using the conventional method and MCLE post-contrast. The proportion of peri-infarct gray zone, core infarct, total infarct relative to LV myocardium mass, papillary muscle infarct scores, and LV functional parameters were statistically compared between groups with and without appropriate ICD therapy during follow-up. RESULTS: Twenty-five patients with prior myocardial infarct for planned ICD implantation (age 64±10 yrs, 88% men, average LVEF 26.2±10.4%) were enrolled. All patients completed the CMR protocol and 6-46 months follow-up at the ICD clinic. Twelve patients had at least one appropriate ICD therapy for ventricular arrhythmias at follow-up. Only the proportion of gray zone measured with MCLE and papillary muscle infarct scores demonstrated a statistically significant difference (P < 0.05) between patients with and without appropriate ICD therapy for ventricular arrhythmias; other CMR derived parameters such as LVEF, core infarct and total infarct did not show a statistically significant difference between these two groups. CONCLUSIONS: Peri-infarct gray zone measurement using MCLE, compared to using conventional LGE-CMR, might be more sensitive in predicting appropriate ICD therapy for ventricular arrhythmia events. Papillary muscle infarct scores might have a specific role for predicting appropriate ICD therapy although the exact mechanism needs further investigation.


Subject(s)
Arrhythmias, Cardiac/therapy , Contrast Media , Defibrillators, Implantable , Electric Countershock/instrumentation , Magnetic Resonance Imaging/methods , Myocardial Infarction/diagnosis , Papillary Muscles/pathology , Patient Selection , Aged , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/physiopathology , Female , Humans , Male , Middle Aged , Myocardial Infarction/complications , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Papillary Muscles/physiopathology , Predictive Value of Tests , Stroke Volume , Ventricular Function, Left
6.
Quant Imaging Med Surg ; 2(1): 12-20, 2012 Mar.
Article in English | MEDLINE | ID: mdl-23256056

ABSTRACT

PURPOSE: To investigate varied manifestations of persistent microvascular obstruction (PMO) and acute left ventricular (LV) remodeling in an experimental reperfused myocardial infarction (MI) using MRI. METHODS: In eleven Yorkshire pigs an acute MI was produced through a 90-minute balloon occlusion of the middle left anterior descending coronary artery, followed by reperfusion. All animals underwent MRI examinations on a 1.5T system including a SSFP functional study, first pass myocardial perfusion (FPMP), T1 preparation Look-Locker and delayed contrast-enhanced MRI (DE-MRI). Imaging was performed immediately post-intervention (day 0) and at days 7-9. In four animals a repeat MRI examination was performed at day 2 as well. Upon study completion, animals underwent histological analysis including infarct assessment with triphenyltetrazolium chloride (TTC). RESULTS: Following reperfusion, Thrombolysis In Myocardial Infarction (TIMI) Flow grade 3 was achieved in all animals, demonstrated by repeat angiography following balloon deflation (day 0). Various MR appearances of PMO were noticed including predominance in the subendocardial region, a central core within the infarcted tissue and also multiple separate clusters. In ten of eleven animals PMO was demonstrated as a persistent hypo-enhanced area in FPMP and DE-MRI, and identified as bright regions in later T1 difference images. In one animal PMO was identified only at day 2. At day 7-9 PMO could be identified on early DE-MRI at 5-15 minutes post Gd injection but not on late DE-MRI and T1 difference images after 45-60 minutes post-contrast. A larger volume of PMO and MI at day 2 was noted in comparison to data from day 0 but the difference was not statistically significant. An increased end-diastolic LV volume (EDV) without changes in end-systolic LV volume (ESV) and LV mass at end-diastolic phase (LVM) was observed at day 7-9 in comparison to data from day 0. There was good correlation between the relative extent of persistent MO in the infarcted myocardium (% MO/MI) and EDV at day 7-9 (r=0.83, n=10, P=0.003). MI was confirmed in all animals by TTC staining and/or histology. CONCLUSION: A variable MR appearance of persistent microvascular obstruction is observed during a short time course MRI study of reperfused acute MI. Acute negative LV remodeling was closely related to the relative extent of persistent microvascular obstruction within the infarct myocardium.

7.
Quant Imaging Med Surg ; 2(2): 81-6, 2012 Jun.
Article in English | MEDLINE | ID: mdl-23256065

ABSTRACT

In this work, we propose a semi-automated myocardial infarction quantification method for cardiac contrast delayed enhancement magnetic resonance images (DE-MRI). Advantages of this method include that it reduces manual contouring of the left ventricle, obviates a remote myocardium region, and automatically distinguishes infarct, healthy and heterogeneous ("gray zone") tissue despite variability in intensity and noise across images. Quantitative evaluation results showed that the automatically determined infarct core and gray zone size have high correlation with that derived from the averaged results of the manual full width at half maximum (FWHM) methods (R(2)=0.99 for infarct core and gray zone size). Compared with the manual method, a much better reproducibility was achieved with the proposed algorithm and it shortens the evaluation time to one second per image, compared with 2-5 min per image for the manual method.

8.
Magn Reson Med ; 66(6): 1739-47, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21630349

ABSTRACT

Left ventricular remodeling as a result of acute myocardial infarction (AMI) is associated with significant morbidity, leading to cardiovascular dysfunction, disability, and death. Despite successful revascularization, coronary vasodilatory dysfunction has been shown in infarcted and remote myocardium of patients following AMI. Our study explored the utility of a T(2)-based blood-oxygen-level-dependent approach in probing regional and longitudinal fluctuations in vasodilatory function in a porcine model of AMI at 3 T. Ten pigs underwent MRI in control state and at day 2, weeks 1-6 following 90 min occlusion followed by reperfusion. The remote myocardium exhibited vasodilatory dysfunction at weeks 1 and 2 that gradually recovered, whereas the infarct zone showed no vasodilatory alterations. Our study suggests that microvascular alterations occurring in infarcted and remote myocardium after AMI might serve as an indicator of adverse left ventricular remodeling. The blood-oxygen-level-dependent technique using quantitative T(2) could potentially be a useful noninvasive tool to evaluate novel therapeutic strategies aimed at limiting vasoconstriction and improving coronary flow reserve after AMI.


Subject(s)
Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Angiography/methods , Myocardial Infarction/blood , Myocardial Infarction/complications , Oxygen/blood , Ventricular Dysfunction, Left/blood , Ventricular Dysfunction, Left/etiology , Animals , Image Enhancement/methods , Myocardial Perfusion Imaging/methods , Reproducibility of Results , Sensitivity and Specificity , Swine
9.
Magn Reson Med ; 66(4): 1129-41, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21337425

ABSTRACT

Pathophysiological responses after acute myocardial infarction include edema, hemorrhage, and microvascular obstruction along with cellular damage. The in vivo evolution of these processes simultaneously throughout infarct healing has not been well characterized. The purpose of our study was to quantitatively monitor the time course of these mechanisms by MRI in a porcine model of myocardial infarction. Ten pigs underwent MRI before coronary occlusion with subgroups studied at day 2 and weeks 1, 2, 4, and 6 post-infarction. Tissue characterization was performed using quantitative T2 and T2* maps to identify edema and hemorrhage, respectively. Contrast-enhanced MRI was used for infarct/ microvascular obstruction delineation. Inflammation was reflected by T2 fluctuations, however at day 2, edema and hemorrhage had counter-acting effects on T2. Hemorrhage (all forms) and mineralization (calcium) could be identified by T2* in the presence of edema. Simultaneous resolution of microvascular obstruction and T2* abnormality suggested that the two phenomenon were closely associated during the healing process. Our study demonstrates that quantitative T2 and T2* mapping techniques allow regional, longitudinal, and cross-subject comparisons and give insights into histological and tissue remodeling processes. Such in vivo characterization will be important in grading severity and evaluating treatment strategies for myocardial infarction, potentially improving clinical outcomes.


Subject(s)
Coronary Vessels/physiopathology , Edema, Cardiac/physiopathology , Hemorrhage/physiopathology , Magnetic Resonance Imaging/methods , Microvessels/physiopathology , Myocardial Infarction/physiopathology , Algorithms , Animals , Contrast Media , Disease Models, Animal , Gadolinium DTPA , Swine
10.
J Magn Reson Imaging ; 33(1): 211-6, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21182141

ABSTRACT

We hypothesized that multicontrast late-enhancement (MCLE) MRI would improve the identification of papillary muscle involvement (PM-MI) in patients with myocardial infarction (MI), compared with conventional late gadolinium enhancement (LGE) MRI using the inversion recovery fast gradient echo (IR-FGRE) technique. Cardiac LGE-MRI studies using both MCLE and IR-FGRE pulse sequences were performed on a 1.5 Tesla (T) MRI system in 23 patients following MI. In all patients, PM-MI was confirmed by the diagnostic criteria as outlined below: (a) the increased signal intensity of PM was the same or similar to that of adjacent hyper-enhanced left ventricular (LV) infarct segments; and (b) the hyper-enhanced PM region was limited to the PM area defined by precontrast cine images of steady-state free precession (SSFP). Visual contrast score was rated according to the differentiation between LV blood pool and hyper-enhanced infarct myocardium. Quantitative contrast-noise ratios (CNR) of infarct relative to blood pool and viable myocardium were also measured on MCLE and IR-FGRE images. Of these 23 patients, 13 studies demonstrated primarily involvement of the territories of the right coronary (RCA, 8 patients) and/or left circumflex (LCX, 5 patients) arteries and 10 involved the territories of left anterior descending artery (LAD) with some LCX involvement. Although both IR-FGRE and MCLE determined the presence and extent of LV MI, better visual contrast scores were achieved in MCLE (2.9 ± 0.3) compared with IR-FGRE (1.6 ± 0.8, P < 0.001). The CNRs of infarct relative to LV blood pool showed a significant statistical difference (n = 23, P < 0.00001) between MCLE (16.2 ± 7.2) and IR-FGRE images (4.8 ± 4.1), which is consistent with the result of visual contrast scores between infarct and LV blood pool. The CNRs of infarct versus viable myocardium did not demonstrate a significant statistical difference (n = 23, P = 0.61) between MCLE (14.4 ± 7.0) and IR-FGRE images (13.6 ± 6.1). MCLE clearly demonstrated PM-MI in all cases (100%, 23/23) while only 39% (9/23) could be visualized on the corresponding IR-FGRE images. In conclusion, MCLE imaging provides better contrast between blood pool and infarct myocardium, thus improving the determination of PM-MI.


Subject(s)
Gadolinium DTPA/administration & dosage , Image Enhancement/methods , Magnetic Resonance Imaging, Cine/methods , Myocardial Infarction/pathology , Papillary Muscles/pathology , Contrast Media/administration & dosage , Female , Humans , Male , Middle Aged , Pilot Projects , Reproducibility of Results , Sensitivity and Specificity
11.
Am J Physiol Heart Circ Physiol ; 299(1): H125-33, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20418483

ABSTRACT

Magnetic resonance imaging (MRI) can track progenitor cells following direct intramyocardial injection. However, in the vast majority of post-myocardial infarction (MI) clinical trials, cells are delivered by the intracoronary (IC) route, which results in far greater dispersion within the myocardium. Therefore, we assessed whether the more diffuse distribution of cells following IC delivery could be imaged longitudinally with MRI. In 11 pigs (7 active, 4 controls), MI was induced by 90-min balloon occlusion of the left anterior descending coronary artery. Seven (0) days [median (interquartile range)] following MI, bone marrow progenitor cells (BMCs) were colabeled with an iron-fluorophore and a cell viability marker and delivered to the left anterior descending coronary artery distal to an inflated over-the-wire percutaneous transluminal coronary angioplasty balloon. T2*-weighted images were used to assess the location of the magnetically labeled cells over a 6-wk period post-MI. Immediately following cell delivery, hypointensity characteristic of the magnetic label was observed in the infarct border rather than within the infarct itself. At 6 wk, the cell signal hypointensity persisted, albeit with significantly decreased intensity. BMC delivery resulted in significant improvement in infarct volume and ejection fraction (EF): infarct volume in cell-treated animals decreased from 7.1 +/- 1.5 to 4.9 +/- 1.0 ml (P < 0.01); infarct volume in controls was virtually unchanged at 4.64 +/- 2.1 to 4.39 +/- 2.1 ml (P = 0.7). EF in cell-treated animals went from 30.4 +/- 5.2% preinjection to 34.5 +/- 2.5% 6 wk postinjection (P = 0.013); EF in control animals went from 34.3 +/- 4.7 to 31.9 +/- 6.8% (P = 0.5). Immunohistochemical analysis revealed intracellular colocalization of the iron fluorophore and cell viability dye with the labeled cells continuing to express the same surface markers as at baseline. MRI can track the persistence and distribution of magnetically labeled BMCs over a 6-wk period following IC delivery. Signal hypointensity declines with time, particularly in the first week following delivery. These cells maintain their original phenotype during this time course. Delivery of these cells appears safe and results in improvement in infarct size and left ventricular ejection fraction.


Subject(s)
Bone Marrow Transplantation , Magnetic Resonance Imaging , Myocardial Infarction/surgery , Myocardium/pathology , Myocytes, Cardiac/pathology , Myocytes, Cardiac/transplantation , Stem Cell Transplantation , Angioplasty, Balloon, Coronary , Animals , Cells, Cultured , Contrast Media , Disease Models, Animal , Ferrosoferric Oxide , Fluorescein-5-isothiocyanate , Fluorescent Dyes , Immunohistochemistry , Injections , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Recovery of Function , Rhodamines , Stroke Volume , Swine , Time Factors , Ventricular Function, Left
12.
Magn Reson Imaging ; 27(2): 147-54, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18687546

ABSTRACT

The purpose of this study was to investigate the feasibility of a noninvasive approach that combines magnetic resonance imaging (MRI) oximetry and flow measurement to obtain the oxygen consumption in the myocardium and in the whole body. Thirteen healthy male volunteers [mean (+/-S.D.) age: 35+/-7 years] underwent this MR study, which included myocardial oxygen consumption (MVO(2)) measurements in 11 subjects and whole-body oxygen consumption (VO(2)) measurements in 8 subjects. In six subjects, both measurements were obtained. Five subjects had repeated MRI measurements of global MVO(2) in order to verify the reproducibility of this approach. The protocol included in vitro blood sample T(2)-%O(2) calibration, coronary sinus (CS) and main pulmonary artery (MPA) T(2) and phase contrast flow measurement and left ventricular (LV) mass calculation. Based on Fick's law, a global measurement of LV MVO(2) and whole-body VO(2) using MRI was feasible. The MVO(2) values were 11+/-3 ml/min per 100 g LV mass. For repeated measurements, differences in MVO(2) of 1 ml/min per 100 g LV mass appear detectable. The whole-body VO(2) values were 3.8+/-0.8 ml/min/kg body weight. MRI techniques that combine CS and MPA T(2), flow and LV mass measurements to quantify MVO(2) and whole-body VO(2) noninvasively in healthy subjects appear feasible, based on their correspondence to previously published work.


Subject(s)
Magnetic Resonance Imaging/methods , Myocardium/metabolism , Oxygen Consumption/physiology , Adult , Blood Flow Velocity , Confidence Intervals , Feasibility Studies , Humans , Male , Reproducibility of Results
13.
J Magn Reson Imaging ; 26(6): 1486-92, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17968957

ABSTRACT

PURPOSE: To investigate a T1 and T2 preparation pulse sequence to evaluate microvascular obstruction (MO) in a porcine model of reperfused acute myocardial infarction (AMI). MATERIALS AND METHODS: A total of 14 pigs with reperfused AMI underwent MRI examinations at baseline and three to four hours after reperfusion. MRI scans included a left ventricular functional study, T1 and T2 measurement on a 1.5T MRI system. At reperfusion, first-pass myocardial perfusion (FPMP) images were obtained after bolus injection of gadopentetate dimeglumine followed by an intravenous drip. Delayed contrast-enhanced MRI (DE-MRI) and T1 measurements were performed 30 and 45 minutes, respectively, after the bolus, during a constant infusion of gadopentetate dimeglumine. RESULTS: In 11 pigs MO was hypoenhanced in FPMP and DE-MRI. In later T1 preparation difference images postcontrast, MO was hyperenhanced while delayed hyperenhanced (DHE) regions appeared dark. MO areas on DE-MRI and T1 images were comparable. T1 reduction (%) postcontrast in MO was small compared to measurements from DHE regions (P < 0.0001) and similar to those from control segments (P = 0.66). Precontrast T1 and T2 values at reperfusion from MO and DHE regions were larger than in control regions. CONCLUSION: Using T1 preparation under a constant gadopentetate dimeglumine (Gd-DTPA) infusion, delayed imaging at 30 to 45 minutes demonstrates MO as a positive contrast with larger T1 values. Elevated T1 and T2 values in MO precontrast may also help to differentiate them from both control and DHE regions.


Subject(s)
Coronary Stenosis/physiopathology , Magnetic Resonance Imaging/methods , Myocardial Infarction/physiopathology , Myocardial Reperfusion , Animals , Contrast Media/administration & dosage , Disease Models, Animal , Gadolinium DTPA/administration & dosage , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Microcirculation/physiopathology , Swine , Time Factors
14.
Radiology ; 228(2): 555-9, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12893906

ABSTRACT

In this study, the authors tested the feasibility of using ultrasonography (US) to monitor catheter-based vascular gene microsphere delivery. Polymeric biodegradable microspheres (mean diameter, 5 microm) were prepared by using a double-emulsion technique to encapsulate DNA-plasmid-encoding green fluorescent protein (GFP) genes. With use of gene-delivery catheters, GFP microspheres were locally delivered into the left femoral arterial walls of six pigs; the contralateral arteries were not infused with microspheres and thus served as negative control vessels. The delivery procedures were monitored with high-frequency (8-15-MHz) transducer US. The effectiveness of monitoring with US was compared with the effectiveness of monitoring with immunohistochemical anti-GFP staining. A highly echogenic "star burst" sign around the entire vessel wall was seen at US and correlated with immunohistochemical findings that showed the destination of the gene microspheres. Study results demonstrate the potential of US for monitoring catheter-based vascular gene microsphere delivery in vivo.


Subject(s)
Catheterization/methods , Genetic Therapy , Ultrasonography, Interventional , Animals , Cardiovascular Diseases/therapy , Feasibility Studies , Genetic Vectors , Green Fluorescent Proteins , Immunohistochemistry , Luminescent Proteins , Microspheres , Plasmids , Swine
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