25 research outputs found
Quantitative Three-dimensional Echocardiography
Echocardiography is the most important non-invasive diagnostic tool for the clinical
management of cardiac patients1. Measurement of left ventricular volume and function
are the most common clinical referral questions to the echocardiography laboratory
because of its value in clinical decision-making, assessment of therapeutic
effects and determination of prognosis. Therefore, an accurate, fast and easy
measurement of left ventricular volume and function is important. Two-dimensional
echocardiography remains the most widely used method, but the advantages of
three-dimensional echocardiography over two-dimensional echocardiography are
increasingl
Three-Dimensional Echocardiographic Analysis of Left Ventricular Function during Hemodialysis
Background: The effects of hemodialysis (HD) on left ventricular (LV) function have been studied by various echocardiographic techniques (M-mode, 2D echocardiography). These studies are hampered by a low accuracy of measurements because of geometric assumptions regarding LV shape. Three-dimensional echocardiography (3DE) overcomes this limitation. Methods: We tested the feasibility of 3DE assessment of LV function during HD. Conventional biplane Simpson rule (BSR) and single plane area length method (SPM) for LV function analysis were used as a reference. Results: 12 HD patients were studied and in 10 (83%) a total of 80 3D datasets were acquired. In 3 patients, one dataset (4%) was of insufficient quality and excluded from analysis. Correlation between SPM, BSR and 3DE for calculation of end-diastolic (EDV, r = 0.89 and r = 0.92, respectively), end-systolic volume (ESV, r = 0.92 and r = 0.93, respectively) and for ejection fraction (EF, r = 0.90 and r = 0.88, respectively) was moderate. Limits-of-agreement results for EDV and ESV were poor with confidence intervals larger than 30 ml. Both 2DE methods underestimated end-diastolic and end-systolic volume, while overestimating ejection fraction. Conclusion: 3DE is feasible for image acquisition during HD, which opens the possibility for accurate and reproducible measurement of LV function during HD. This may improve the assessment of the acute effect of HD on LV performance, and guide therapeutic strategies aimed at preventing intradialytic hypotension
Imaging of atherosclerosis, targeting LFA-1 on inflammatory cells with 111In-DANBIRT
Background: 111In-DOTA-butylamino-NorBIRT (DANBIRT) is a novel radioligand which binds to Leukocyte Function-associated Antigen-1 (LFA-1), expressed on inflammatory cells. This study evaluated 111In-DANBIRT for the visualization of atherosclerotic plaque inflammation in mice. Methods and Results: ApoE−/− mice, fed an atherogenic diet up to 20 weeks (n = 10), were imaged by SPECT/CT 3 hours post injection of 111In-DANBIRT (~ 200 pmol, ~ 40 MBq). Focal spots of 111In-DANBIRT were visible in the aortic arch of all animals, with an average Target-to-Background Ratio (TBR) of 1.7 ± 0.5. In vivo imaging results were validated by ex vivo SPECT/CT imaging, with a TBR up to 11.5 (range 2.6 to 11.5). Plaques, identified by Oil Red O lipid-staining on excised arteries, co-localized with 111In-DANBIRT uptake as determined by ex vivo autoradiography. Subsequent histological processing and in vitro autoradiography confirmed 111In-DANBIRT uptake at plaque areas containing CD68 expressing macrophages and LFA-1 expressing inflammatory cells. Ex vivo incubation of a human carotid endarterectomy specimen with 111In-DANBIRT (~ 950 nmol, ~ 190 MBq) for 2 hours showed heterogeneous plaque uptake on SPECT/CT, after which immunohistochemical analysis demonstrated co-localization of 111In-DANBIRT uptake and CD68 and LFA-1 expressing cells. Conclusions: Our results indicate the potential of radiolabeled DANBIRT as a relevant imaging radioligand for non-invasive evaluation of atherosclerotic inflammation
Pulsed wave tissue Doppler imaging for the quantification of contractile reserve in stunned, hibernating, and scarred myocardium
OBJECTIVES: To assess whether quantification of myocardial systolic
velocities by pulsed wave tissue Doppler imaging can differentiate between
stunned, hibernating, and scarred myocardium. DESIGN: Observational study.
SETTING: Tertiary referral centre. PATIENTS: 70 patients with reduced left
ventricular function caused by chronic coronary artery disease. METHODS:
Pulsed wave tissue Doppler imaging was done close to the mitral annulus at
rest and during low dose dobutamine; systolic ejection velocity (Vs) and
the difference in Vs between low dose dobutamine and the resting value
(DeltaVs) were assessed using a six segment model. Assessment of perfusion
(with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by
18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions
(by resting cross sectional echocardiography) as stunned, hibernating, or
scarred. RESULTS: 253 of 420 regions (60%) were dysfunctional. Of these,
132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96
(38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue
was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by
ANOVA). There was a gradual decline in Vs during low dose dobutamine
infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8
(1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned
(2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred
regions (1.3 (1.2) cm/s, p = 0.001). CONCLUSIONS: Quantitative tissue
Doppler imaging showed a gradual reduction in regional velocities between
stunned, hibernating, and scarred myocardium. Dobutamine induced
contractile reserve was higher in stunned regions than in hibernating and
scarred myocardium, reflecting different severities of myocardial damag
Imaging inflammation in atherosclerotic plaques, targeting SST2 with [111In]In-DOTA-JR11
Background: Imaging Somatostatin Subtype Receptor 2 (SST2) expressing macrophages by [DOTA,Tyr3]-octreotate (DOTATATE) has proven successful for plaque detection. DOTA-JR11 is a SST2 targeting ligand with a five times higher tumor uptake than DOTATATE, and holds promise to improve plaque imaging. The aim of this study was to evaluate the potential of DOTA-JR11 for plaque detection. Methods and Results: Atherosclerotic ApoE−/− mice (n = 22) fed an atherogenic diet were imaged by SPECT/CT two hours post injection of [111In]In-DOTA-JR11 (~ 200 pmol, ~ 50 MBq). In vivo plaque uptake of [111In]In-DOTA-JR11 was visible in all mice, with a target-to-background-ratio (TBR) of 2.23 ± 0.35. Post-mortem scans after thymectomy and ex vivo scans of the arteries after excision of the arteries confirmed plaque uptake of the radioligand with TBRs of 2.46 ± 0.52 and 3.43 ± 1.45 respectively. Oil red O lipid-staining and ex vivo autoradiography of excised arteries showed [111In]In-DOTA-JR11 uptake at plaque locations. Histological processing showed CD68 (macrophages) and SST2 expressing cells in plaques. SPECT/CT, in vitro autoradiography and immunohistochemistry performed on slices of a human carotid endarterectomy sample showed [111In]In-DOTA-JR11 uptake at plaque locations containing CD68 and SST2 expressing cells. Conclusions: The results of this study indicate DOTA-JR1
True mitral annulus diameter is underestimated by two-dimensional echocardiography as evidenced by real-time three-dimensional echocardiography and magnetic resonance imaging
Background: Mitral annulus assessment is of great importance for the diagnosis and treatment of mitral valve disease. The present study sought to assess the value of real-time three-dimensional echocardiography for the assessment of true mitral annulus diameter (MAD). Methods: One hundred and fifty patients (mean age 38 ± 18 years) with adequate two-dimensional (2D) echocardiographic image quality underwent assessment of MAD2Dand MAD3D(with real-time three-dimensional echocardiography). In a subgroup of 30 patients true MAD was validated with magnetic resonance imaging (MRI). Results: There was a good interobserver agreement for MAD2D(mean difference = -0.25 ± 2.90 mm, agreement: -3.16, 2.66) and MAD3D(mean difference = 0.29 ± 2.03, agreement = -1.74, 2.32). Measurements of MAD2Dand MAD3Dwere well correlated (R = 0.81, P < 0.0001). However, MAD3Dwas significantly larger than MAD2D(3.7 ± 0.9 vs. 3.3 ± 0.8 cm, P < 0.0001). In the subgroup of 30 patients with MRI validation, MAD3Dand MADMRIwere significantly larger than MAD2D(3.3 ± 0.5 and 3.4 ± 0.5 cm vs. 2.9 ± 0.4 cm, both P < 0.001). There was no significant difference between MADMRIand MAD3D. Conclusion: MAD3Dcan be reliably measured and is superior to MAD2Din the assessment of true mitral annular size
Long term outcome in patients with silent versus symptomatic ischaemia during dobutamine stress echocardiography
OBJECTIVES: To compare the long term prognosis of patients having silent
versus symptomatic ischaemia during dobutamine stress echocardiography
(DSE). DESIGN: Observational study. SETTING: Tertiary referral centre.
PATIENTS: 931 patients who experienced stress induced myocardial ischaemia
during DSE. RESULTS: Silent ischaemia was present in 643 of 931 patients
(69%). The number of dysfunctional segments at rest (mean (SD) 9.6 (5.1) v
8.8 (5.0), p = 0.1) and of ischaemic segments (3.5 (2.2) v 3.8 (2.1), p =
0.2) was comparable in both groups. During a mean (SD) follow up of 5.5
(3.3) years, there were 169 (18%) cardiac deaths and 86 (9%) non-fatal
infarctions. Multivariable Cox regression analysis showed age (hazard
ratio (HR) 1.1, 95% confidence interval (CI) 1.02 to 1.05), previous
myocardial infarction (HR 1.4, 95% CI 1.1 to 2.0), and number of ischaemic
segments during the test (HR 2.0, 95% CI 1.0 to 3.7) as independent
predictors of cardiac death and myocardial infarction. For every
additional ischaemic segment there was a twofold increment in risk of late
cardiac events. The annual cardiac death or myocardial infarction rate was
3.0% in patients with symptomatic ischaemia and 4.6% in patients with
silent ischaemia (p < 0.01). Silent induced ischaemia was an independent
predictor of cardiac death and myocardial infarction (HR 1.7, 95% CI 1.1
to 2.0). During follow up symptomatic patients were treated more often
with cardioprotective therapy (p < 0.01) and coronary revascularisation
(145 of 288 (50%) v 174 of 643 (27%), p < 0.001). CONCLUSIONS: Patients
with silent ischaemia had a similar extent of myocardial ischaemia during
DSE compared to patients with symptomatic ischaemia but received less
cardioprotective treatment and coronary revascularisation and experienced
a higher cardiac event rate
Imaging of inflammatory cellular protagonists in human atherosclerosis: a dual-isotope SPECT approach
Purpose: Atherosclerotic plaque development and progression signifies a complex inflammatory disease mediated by a multitude of proinflammatory leukocyte subsets. Using single photon emission computed tomography (SPECT) coupled with computed tomography (CT), this study tested a new dual-isotop