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Nakajima K, Shibutani T, Massanes F, Shimizu T, Yoshida S, Onoguchi M, Kinuya S, Vija AH. Myocardial perfusion imaging with retrospective gating and integrated correction of attenuation, scatter, respiration, motion, and arrhythmia. J Nucl Cardiol 2023; 30:2773-2789. [PMID: 37758961 PMCID: PMC10682219 DOI: 10.1007/s12350-023-03374-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 09/29/2023]
Abstract
BACKGROUND Absolute quantitative myocardial perfusion SPECT requires addressing of aleatory and epistemic uncertainties in conjunction with providing image quality sufficient for lesion detection and characterization. Iterative reconstruction methods enable the mitigation of the root causes of image degradation. This study aimed to determine the feasibility of a new SPECT/CT method with integrated corrections attempting to enable absolute quantitative cardiac imaging (xSPECT Cardiac; xSC). METHODS We compared images of prototype xSC and conventional SPECT (Flash3DTM) acquired at rest from 56 patients aged 71 ± 12 y with suspected coronary heart disease. The xSC prototype comprised list-mode acquisitions with continuous rotation and subsequent iterative reconstructions with retrospective electrocardiography (ECG) gating. Besides accurate image formation modeling, patient-specific CT-based attenuation and energy window-based scatter correction, additionally we applied mitigation for patient and organ motion between views (inter-view), and within views (intra-view) for both the gated and ungated reconstruction. We then assessed image quality, semiquantitative regional values, and left ventricular function in the images. RESULTS The quality of all xSC images was acceptable for clinical purposes. A polar map showed more uniform distribution for xSC compared with Flash3D, while lower apical count and higher defect contrast of myocardial infarction (p = 0.0004) were observed on xSC images. Wall motion, 16-gate volume curve, and ejection fraction were at least acceptable, with indication of improvements. The clinical prospectively gated method rejected beats ≥20% in 6 patients, whereas retrospective gating used an average of 98% beats, excluding 2% of beats. We used the list-mode data to create a product equivalent prospectively gated dataset. The dataset showed that the xSC method generated 18% higher count data and images with less noise, with comparable functional variables of volume and LVEF (p = ns). CONCLUSIONS Quantitative myocardial perfusion imaging with the list-mode-based prototype xSPECT Cardiac is feasible, resulting in images of at least acceptable image quality.
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Affiliation(s)
- Kenichi Nakajima
- Functional Imaging and Artificial Intelligence, Kanazawa University, Kanazawa, 920-8640, Japan.
| | - Takayuki Shibutani
- Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Francesc Massanes
- Siemens Medical Solutions USA, Inc. Molecular Imaging, Hoffman Estates, IL, USA
| | - Takeshi Shimizu
- Siemens Medical Solutions USA, Inc. Molecular Imaging, Hoffman Estates, IL, USA
| | - Shohei Yoshida
- Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Masahisa Onoguchi
- Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan
| | - Seigo Kinuya
- Department of Nuclear Medicine, Kanazawa University, Kanazawa, Japan
| | - A Hans Vija
- Siemens Medical Solutions USA, Inc. Molecular Imaging, Hoffman Estates, IL, USA
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Metzler SD, Moore SC. Analytic Determination of Rectangular-Pinhole Sensitivity With Penetration. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:833-843. [PMID: 31425068 PMCID: PMC7241287 DOI: 10.1109/tmi.2019.2936187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Modern small-animal SPECT systems use multiple pinhole collimators per detector to increase sensitivity while still maintaining high resolution. This resolution is a combination of aperture resolution combined with detector resolution, which is mitigated by magnification. Higher magnification results in better resolution, but fewer apertures per detector. When multiple pinhole collimators project onto the same detector, those with a rectangular field of view (FOV) can be packed more tightly than those with a circular FOV. In addition, a rectangular aperture can be used to obtain different resolution-sensitivity tradeoffs in the two orthogonal directions. Thus, these rectangular-pinhole collimators can have independent FOVs and independent resolution values in the two directions of the rectangular aperture. Previous work has determined the amount of penetration for circular pinholes (i.e., circular apertures with circular FOVs), where the pinhole walls were modeled as cones. In this work, a formula for the penetrative sensitivity for rectangular apertures with a rectangular FOV is determined. The formula was validated using numerical calculations for various combinations of acceptance angles, aperture sizes, linear attenuation coefficients, and incidence angles.
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3
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Cicone F, Viertl D, Quintela Pousa AM, Denoël T, Gnesin S, Scopinaro F, Vozenin MC, Prior JO. Cardiac Radionuclide Imaging in Rodents: A Review of Methods, Results, and Factors at Play. Front Med (Lausanne) 2017; 4:35. [PMID: 28424774 PMCID: PMC5372793 DOI: 10.3389/fmed.2017.00035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/15/2017] [Indexed: 12/19/2022] Open
Abstract
The interest around small-animal cardiac radionuclide imaging is growing as rodent models can be manipulated to allow the simulation of human diseases. In addition to new radiopharmaceuticals testing, often researchers apply well-established probes to animal models, to follow the evolution of the target disease. This reverse translation of standard radiopharmaceuticals to rodent models is complicated by technical shortcomings and by obvious differences between human and rodent cardiac physiology. In addition, radionuclide studies involving small animals are affected by several extrinsic variables, such as the choice of anesthetic. In this paper, we review the major cardiac features that can be studied with classical single-photon and positron-emitting radiopharmaceuticals, namely, cardiac function, perfusion and metabolism, as well as the results and pitfalls of small-animal radionuclide imaging techniques. In addition, we provide a concise guide to the understanding of the most frequently used anesthetics such as ketamine/xylazine, isoflurane, and pentobarbital. We address in particular their mechanisms of action and the potential effects on radionuclide imaging. Indeed, cardiac function, perfusion, and metabolism can all be significantly affected by varying anesthetics and animal handling conditions.
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Affiliation(s)
- Francesco Cicone
- Department of Nuclear Medicine and Molecular Imaging, University Hospital of Lausanne, Lausanne, Switzerland.,Nuclear Medicine, Department of Surgical and Medical Sciences and Translational Medicine, "Sapienza" University of Rome, Rome, Italy
| | - David Viertl
- Department of Nuclear Medicine and Molecular Imaging, University Hospital of Lausanne, Lausanne, Switzerland
| | - Ana Maria Quintela Pousa
- Laboratory of Radiation Oncology, Service of Radiation-Oncology, Department of Oncology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Thibaut Denoël
- Department of Nuclear Medicine and Molecular Imaging, University Hospital of Lausanne, Lausanne, Switzerland
| | - Silvano Gnesin
- Institute of Radiation Physics, University Hospital of Lausanne, Lausanne, Switzerland
| | - Francesco Scopinaro
- Nuclear Medicine, Department of Surgical and Medical Sciences and Translational Medicine, "Sapienza" University of Rome, Rome, Italy
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Service of Radiation-Oncology, Department of Oncology, University Hospital of Lausanne, Lausanne, Switzerland
| | - John O Prior
- Department of Nuclear Medicine and Molecular Imaging, University Hospital of Lausanne, Lausanne, Switzerland
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Perez J, Diaz N, Tandon I, Plate R, Martindale C, Balachandran K. Elevated Serotonin Interacts with Angiotensin-II to Result in Altered Valve Interstitial Cell Contractility and Remodeling. Cardiovasc Eng Technol 2017; 9:168-180. [PMID: 28247311 DOI: 10.1007/s13239-017-0298-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/22/2017] [Indexed: 01/30/2023]
Abstract
While the valvulopathic effects of serotonin (5HT) and angiotensin-II (Ang-II) individually are known, it was not clear how 5HT and Ang-II might interact, specifically in the context of the mechanobiological responses due to altered valve mechanics potentiated by these molecules. In this context, the hypothesis of this study was that increased serotonin levels would result in accelerated progression toward disease in the presence of angiotensin-II-induced hypertension. C57/BL6 J mice were divided into four groups and subcutaneously implanted with osmotic pumps containing: PBS (control), 5HT (2.5 ng/kg/min), Ang-II (400 ng/kg/min), and 5HT + Ang-II (combination). Blood pressure was monitored using the tail cuff method. Echocardiography was performed on the mice before surgery and every week thereafter to assess ejection fraction. After three weeks, the mice were sacrificed and their hearts excised, embedded and sectioned for analysis of the aortic valves via histology and immunohistochemistry. In separate experiments, porcine valve interstitial cells (VICs) were directly stimulated with 5HT (10-7 M), Ang-II (100 nM) or both and assayed for cellular contractility, cytoskeletal organization and collagen remodeling. After three weeks, average systolic blood pressure was significantly increased in the 5HT, Ang-II and combination groups compared to control. Echocardiographic analysis demonstrated significantly reduced ejection fraction in Ang-II and the combination groups. H&E staining demonstrated thicker leaflets in the combination groups, suggesting a more aggressive remodeling process. Picrosirius red staining and image analysis suggested that the Ang-II and combination groups had the largest proportion of thicker collagen fibers. VIC orientation, cellular contractility and collagen gene expression was highest for the 5HT + Ang-II combination treatment compared to all other groups. Overall, our results suggest that 5HT and Ang-II interact to result in significantly detrimental alteration of function and remodeling in the valve.
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Affiliation(s)
- Jessica Perez
- Department of Biomedical Engineering, University of Arkansas, 122 John A. White Jr. Engineering Hall, Fayetteville, AR, 72701, USA
| | - Nancy Diaz
- Department of Biomedical Engineering, University of Arkansas, 122 John A. White Jr. Engineering Hall, Fayetteville, AR, 72701, USA
| | - Ishita Tandon
- Department of Biomedical Engineering, University of Arkansas, 122 John A. White Jr. Engineering Hall, Fayetteville, AR, 72701, USA
| | - Rachel Plate
- Department of Biomedical Engineering, University of Arkansas, 122 John A. White Jr. Engineering Hall, Fayetteville, AR, 72701, USA
| | - Christopher Martindale
- Department of Biomedical Engineering, University of Arkansas, 122 John A. White Jr. Engineering Hall, Fayetteville, AR, 72701, USA
| | - Kartik Balachandran
- Department of Biomedical Engineering, University of Arkansas, 122 John A. White Jr. Engineering Hall, Fayetteville, AR, 72701, USA.
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Dickel DE, Barozzi I, Zhu Y, Fukuda-Yuzawa Y, Osterwalder M, Mannion BJ, May D, Spurrell CH, Plajzer-Frick I, Pickle CS, Lee E, Garvin TH, Kato M, Akiyama JA, Afzal V, Lee AY, Gorkin DU, Ren B, Rubin EM, Visel A, Pennacchio LA. Genome-wide compendium and functional assessment of in vivo heart enhancers. Nat Commun 2016; 7:12923. [PMID: 27703156 PMCID: PMC5059478 DOI: 10.1038/ncomms12923] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/16/2016] [Indexed: 12/04/2022] Open
Abstract
Whole-genome sequencing is identifying growing numbers of non-coding variants in human disease studies, but the lack of accurate functional annotations prevents their interpretation. We describe the genome-wide landscape of distant-acting enhancers active in the developing and adult human heart, an organ whose impairment is a predominant cause of mortality and morbidity. Using integrative analysis of >35 epigenomic data sets from mouse and human pre- and postnatal hearts we created a comprehensive reference of >80,000 putative human heart enhancers. To illustrate the importance of enhancers in the regulation of genes involved in heart disease, we deleted the mouse orthologs of two human enhancers near cardiac myosin genes. In both cases, we observe in vivo expression changes and cardiac phenotypes consistent with human heart disease. Our study provides a comprehensive catalogue of human heart enhancers for use in clinical whole-genome sequencing studies and highlights the importance of enhancers for cardiac function. Identification of non-coding variants has outstripped our ability to annotate and interpret them. Dickel et al. present a compendium of over 80,000 putative human heart enhancers and demonstrate that two conserved enhancers are required for proper cardiac function in mice.
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Affiliation(s)
- Diane E Dickel
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Iros Barozzi
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Yiwen Zhu
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Yoko Fukuda-Yuzawa
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Marco Osterwalder
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Brandon J Mannion
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Dalit May
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Cailyn H Spurrell
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Ingrid Plajzer-Frick
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Catherine S Pickle
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Elizabeth Lee
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Tyler H Garvin
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Momoe Kato
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Jennifer A Akiyama
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Veena Afzal
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Ah Young Lee
- Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - David U Gorkin
- Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Bing Ren
- Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA.,Department of Cellular and Molecular Medicine, University of California, San Diego School of Medicine, La Jolla, California 92093, USA
| | - Edward M Rubin
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.,U.S. Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Axel Visel
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.,U.S. Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA.,School of Natural Sciences, University of California, Merced, Merced, California 95343, USA
| | - Len A Pennacchio
- Functional Genomics Department, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.,U.S. Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
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6
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Hendrikx G, Bauwens M, Wierts R, Mottaghy FM, Post MJ. Left ventricular function measurements in a mouse myocardial infarction model. Comparison between 3D-echocardiography and ECG-gated SPECT. Nuklearmedizin 2016; 55:115-22. [PMID: 27046440 DOI: 10.3413/nukmed-0776-15-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/22/2016] [Indexed: 12/20/2022]
Abstract
AIM To assess the accuracy of ECG-gated micro (µ)-SPECT in a mouse myocardial infarction (MI) model in comparison to 3D-echocardiography. ANIMALS, METHODS In a mouse (Swiss mice) MI model we compared the accuracy of technetium-99m sestamibi (99mTc-sestamibi) myocardial perfusion, electrocardiogram (ECG) gated µSPECT to 3D-echocardiography in determining left ventricular function. 3D-echocardiography and myocardial perfusion ECG-gated µSPECT data were acquired in the same animal at baseline (n = 11) and 7 (n = 8) and 35 (n = 9) days post ligation of the left anterior descending coronary artery (LAD). Sham operated mice were used as a control (8, 6 and 7 mice respectively). Additionally, after day 35 µSPECT scans, hearts were harvested and 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) staining and autoradiography was performed to determine infarct size. RESULTS In both infarcted and sham-operated mice we consistently found comparable values for the end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) obtained by 3D-echocardiography and ECG-gated µSPECT. Excellent correlations between measurements from 3D-echocardiography and ECG-gated µSPECT were found for EDV, ESV and EF (r = 0.9532, r = 0.9693 respectively and r = 0.9581) in infarcted mice. Furthermore, comparable infarct size values were found at day 35 post MI by TTC staining and autoradiography (27.71 ± 1.80% and 29.20 ± 1.18% with p = 0.43). CONCLUSION We have demonstrated that ECG-gated µSPECT imaging provides reliable left ventricular function measurements in a mouse MI model. Obtained results were comparable to the highly accurate 3D-echocardiography. This, in addition to the opportunity to simultaneously image multiple biological processes during a single acquisition makes µSPECT imaging a serious option for studying cardiovascular disease in small animals.
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Affiliation(s)
| | | | | | - Felix M Mottaghy
- Prof. Dr. Felix M. Mottaghy, Department of Nuclear Medicine, Maastricht University Medical Centre (MUMC+), Postbox 5800, 6202 AZ Maastricht, The Netherlands, Tel. +31/433 87 49 11,
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Abstract
PURPOSE The objective of this study was to compare a new generation of four-dimensional micro-single photon emission computed tomography (microSPECT) with microCT for the quantitative in vivo assessment of murine cardiac function. PROCEDURES Four-dimensional isotropic cardiac images were acquired from anesthetized normal C57BL/6 mice with either microSPECT (n = 6) or microCT (n = 6). One additional mouse with myocardial infarction (MI) was scanned with both modalities. Prior to imaging, mice were injected with either technetium tetrofosmin for microSPECT or a liposomal blood pool contrast agent for microCT. Segmentation of the left ventricle (LV) was performed using Vitrea (Vital Images) software, to derive global and regional function. RESULTS Measures of global LV function between microSPECT and microCT groups were comparable (e.g., ejection fraction = 71 ± 6 % microSPECT and 68 ± 4 % microCT). Regional functional indices (wall motion, wall thickening, regional ejection fraction) were also similar for the two modalities. In the mouse with MI, microSPECT identified a large perfusion defect that was not evident with microCT. CONCLUSIONS Despite lower spatial resolution, microSPECT was comparable to microCT in the quantitative evaluation of cardiac function. MicroSPECT offers an advantage over microCT in the ability to evaluate simultaneously myocardial radiotracer distribution and function, simultaneously. MicroSPECT should be considered as an alternative to microCT and magnetic resonance for preclinical cardiac imaging in the mouse.
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Todica A, Brunner S, Böning G, Lehner S, Nekolla SG, Wildgruber M, Übleis C, Wängler C, Sauter M, Klingel K, Cumming P, Bartenstein P, Schirrmacher R, Franz WM, Hacker M. [68Ga]-albumin-PET in the monitoring of left ventricular function in murine models of ischemic and dilated cardiomyopathy: comparison with cardiac MRI. Mol Imaging Biol 2014; 15:441-9. [PMID: 23408338 DOI: 10.1007/s11307-013-0618-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE The purpose of this study is to evaluate left ventricular functional parameters in healthy mice and in different murine models of cardiomyopathy with the novel blood pool (BP) positron emission tomography (PET) tracer [68Ga]-albumin. PROCEDURES ECG-gated microPET examinations were obtained in healthy mice, and mice with dilative (DCM) and ischemic cardiomyopathy (ICM) using the novel BP tracer [68Ga]-albumin (AlbBP), as well as [18F]-FDG microPET. Cine-magnetic resonance imaging (MRI) examination performed on a clinical 1.5-T MRI provided the reference standard measurements. RESULTS When considering the combined group of healthy controls, DCM and ICM AlbBP-PET significantly overestimated the magnitudes of EDV (AlbBP, 181±86 μl; cine-MRI, 125±80 μl; P<0.001) and ESV (AlbBP, 136±92 μl; cine-MRI, 96±77 μl; P<0.001), whereas the EF (AlbBP, 31±16%; cine-MRI, 33±21%; P=0.910) matched closely to cine-MRI results, as did findings with [18F]-FDG. High correlations were found between the measured cardiac parameters (EDV: R=0.978, ESV: R=0.989, and LVEF: R=0.992). CONCLUSIONS Measuring left ventricular function in mice with [68Ga]-albumin BP PET is feasible and showed a high correlation compared to cine-MRI, which was used as a reference standard.
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Affiliation(s)
- Andrei Todica
- Department of Nuclear Medicine, Ludwig-Maximilians-University, Klinikum Grosshadern, Munich, Germany
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Zhong M, Kundu BK. Optimization of a Model Corrected Blood Input Function from Dynamic FDG-PET Images of Small Animal Heart In Vivo. IEEE TRANSACTIONS ON NUCLEAR SCIENCE 2013; 60:3417-3422. [PMID: 24741130 PMCID: PMC3985393 DOI: 10.1109/tns.2013.2269032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Quantitative evaluation of dynamic Positron Emission Tomography (PET) of mouse heart in vivo is challenging due to the small size of the heart and limited intrinsic spatial resolution of the PET scanner. Here, we optimized a compartment model which can simultaneously correct for spill over and partial volume effects for both blood pool and the myocardium, compute kinetic rate parameters and generate model corrected blood input function (MCBIF) from ordered subset expectation maximization - maximum a posteriori (OSEM-MAP) cardiac and respiratory gated 18F-FDG PET images of mouse heart with attenuation correction in vivo, without any invasive blood sampling. Arterial blood samples were collected from a single mouse to indicate the feasibility of the proposed method. In order to establish statistical significance, venous blood samples from n=6 mice were obtained at 2 late time points, when SP contamination from the tissue to the blood is maximum. We observed that correct bounds and initial guesses for the PV and SP coefficients accurately model the wash-in and wash-out dynamics of the tracer from mouse blood. The residual plot indicated an average difference of about 1.7% between the blood samples and MCBIF. The downstream rate of myocardial FDG influx constant, Ki (0.15±0.03 min-1), compared well with Ki obtained from arterial blood samples (P=0.716). In conclusion, the proposed methodology is not only quantitative but also reproducible.
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Affiliation(s)
- Min Zhong
- Department of Physics, Radiology and Medical Imaging, University of Virginia, VA 22903 USA (telephone: 434-260-0507, )
| | - Bijoy K Kundu
- Department of Radiology and Medical Imaging, University of Virginia, VA 22908 USA (telephone: 434-924-0284, )
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Curcio A, Torella D, Iaconetti C, Pasceri E, Sabatino J, Sorrentino S, Giampà S, Micieli M, Polimeni A, Henning BJ, Leone A, Catalucci D, Ellison GM, Condorelli G, Indolfi C. MicroRNA-1 downregulation increases connexin 43 displacement and induces ventricular tachyarrhythmias in rodent hypertrophic hearts. PLoS One 2013; 8:e70158. [PMID: 23922949 PMCID: PMC3724819 DOI: 10.1371/journal.pone.0070158] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 06/19/2013] [Indexed: 01/11/2023] Open
Abstract
Downregulation of the muscle-specific microRNA-1 (miR-1) mediates the induction of pathologic cardiac hypertrophy. Dysfunction of the gap junction protein connexin 43 (Cx43), an established miR-1 target, during cardiac hypertrophy leads to ventricular tachyarrhythmias (VT). However, it is still unknown whether miR-1 and Cx43 are interconnected in the pro-arrhythmic context of hypertrophy. Thus, in this study we investigated whether a reduction in the extent of cardiac hypertrophy could limit the pathological electrical remodeling of Cx43 and the onset of VT by modulating miR-1 levels. Wistar male rats underwent mechanical constriction of the ascending aorta to induce pathologic left ventricular hypertrophy (LVH) and afterwards were randomly assigned to receive 10mg/kg valsartan, VAL (LVH+VAL) delivered in the drinking water or placebo (LVH) for 12 weeks. Sham surgery was performed for control groups. Programmed ventricular stimulation reproducibly induced VT in LVH compared to LVH+VAL group. When compared to sham controls, rats from LVH group showed a significant decrease of miR-1 and an increase of Cx43 expression and its ERK1/2-dependent phosphorylation, which displaces Cx43 from the gap junction. Interestingly, VAL administration to rats with aortic banding significantly reduced cardiac hypertrophy and prevented miR-1 down-regulation and Cx43 up-regulation and phosphorylation. Gain- and loss-of-function experiments in neonatal cardiomyocytes (NCMs) in vitro confirmed that Cx43 is a direct target of miR-1. Accordingly, in vitro angiotensin II stimulation reduced miR-1 levels and increased Cx43 expression and phosphorylation compared to un-stimulated NCMs. Finally, in vivo miR-1 cardiac overexpression by an adenoviral vector intra-myocardial injection reduced Cx43 expression and phosphorylation in mice with isoproterenol-induced LVH. In conclusion, miR-1 regulates Cx43 expression and activity in hypertrophic cardiomyocytes in vitro and in vivo. Treatment of pressure overload-induced myocyte hypertrophy reduces the risk of life-threatening VT by normalizing miR-1 expression levels with the consequent stabilization of Cx43 expression and activity within the gap junction.
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Affiliation(s)
- Antonio Curcio
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Daniele Torella
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
- Biostem Unit, RISES, Liverpool John Moores University, Liverpool, United Kingdom
| | - Claudio Iaconetti
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Eugenia Pasceri
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Jolanda Sabatino
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Sabato Sorrentino
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Salvatore Giampà
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Mariella Micieli
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Alberto Polimeni
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Beverley J. Henning
- Biostem Unit, RISES, Liverpool John Moores University, Liverpool, United Kingdom
| | - Angelo Leone
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Daniele Catalucci
- Humanitas Clinical and Research Center, Rozzano, Milan, and National Research Council, Italy
| | - Georgina M. Ellison
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
- Biostem Unit, RISES, Liverpool John Moores University, Liverpool, United Kingdom
| | - Gianluigi Condorelli
- Humanitas Clinical and Research Center, Rozzano, Milan, and National Research Council, Italy
| | - Ciro Indolfi
- Division of Cardiology, Laboratory of Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
- URT - National Research Council, University Magna Graecia, Catanzaro, Italy
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Todica A, Böning G, Lehner S, Weidl E, Cumming P, Wängler C, Nekolla SG, Schwaiger M, Bartenstein P, Schirrmacher R, Hacker M. Positron emission tomography in the assessment of left ventricular function in healthy rats: a comparison of four imaging methods. J Nucl Cardiol 2013; 20:262-74. [PMID: 23255241 DOI: 10.1007/s12350-012-9663-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 11/30/2012] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To measure left ventricular (LV) function parameters in heart of healthy rats by three different positron emission tomography (PET) imaging techniques and by magnetic resonance imaging (MRI). METHODS ECG-gated microPET examinations were obtained in seven healthy rats with 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) for calculation of LV-function from the blood-pool phase of the dynamic recording (FDGBP), and also from the later myocardial uptake (FDGMyo). On subsequent days, we re-measured LV-function using the novel blood-pool tracer (68)Ga-albumin (AlbBP) and again by FDG (FDGMyo2) in one setting. Cine-MRI examination provided the reference standard measurement. RESULTS The mean LV ejection fractions (LVEF) were 56 ± 3 (FDGBP), 55 ± 3 (FDGMyo), 56 ± 3 (FDGMyo2), 57 ± 3 (AlbBP), and 57 ± 2 (MRI). There were good to excellent correlations found between the LVEF-values as compared to MRI reference standard for FDGBP (r = 0.71), FDGMyo (r = 0.86) and AlbBP (r = 0.88). Both of the blood-pool methods significantly overestimated the magnitudes of end-diastolic-volume and end-systolic-volume, whereas FDGMyo matched closely to the MRI reference standard. There was no significant bias for both blood-pool methods and a minor negative bias for FDGMyo regarding the LV ejection fraction (LVEF) when compared to cine-MRI results. There was no significant difference between the means of FDGMyo and FDGMyo2 (P = .50). CONCLUSIONS Relative to reference standard MRI measurements of LVEF, there was excellent agreement between PET-based measurements, notably for the novel blood-pool tracer (68)Ga-albumin.
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Affiliation(s)
- Andrei Todica
- Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany
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12
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Benavides-Vallve C, Corbacho D, Iglesias-Garcia O, Pelacho B, Albiasu E, Castaño S, Muñoz-Barrutia A, Prosper F, Ortiz-de-Solorzano C. New strategies for echocardiographic evaluation of left ventricular function in a mouse model of long-term myocardial infarction. PLoS One 2012; 7:e41691. [PMID: 22848568 PMCID: PMC3407217 DOI: 10.1371/journal.pone.0041691] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 06/25/2012] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND The aim of this article is to present an optimized acquisition and analysis protocol for the echocardiographic evaluation of left ventricle (LV) remodeling in a mouse model of myocardial infarction (MI). METHODOLOGY 13 female DBA/2J mice underwent permanent occlusion of the left anterior descending (LAD) coronary artery leading to MI. Mice echocardiography was performed using a Vevo 770 (Visualsonics, Canada) before infarction, and 7, 14, 30, 60, 90 and 120 days after LAD ligation. LV systolic function was evaluated using different parameters, including the fractional area change (FAC%) computed in four high-temporal resolution B-mode short axis images taken at different ventricular levels, and in one parasternal long axis. Pulsed wave and tissue Doppler modes were used to evaluate the diastolic function and Tei Index for global cardiac function. The echocardiographic measurements of infarct size were validated histologically using collagen deposition labeled by Sirius red staining. All data was analyzed using Shapiro-Wilk and Student's t-tests. PRINCIPAL FINDINGS Our results reveal LV dilation resulting in marked remodeling an severe systolic dysfunction, starting seven days after MI (LV internal apical diameter, basal = 2.82±0.24, 7d = 3.49±0.42; p<0.001. End-diastolic area, basal = 18.98±1.81, 7d = 22.04±2.11; p<0.001). A strong statistically significant negative correlation exists between the infarct size and long-axis FAC% (r = -0.946; R(2) = 0.90; p<0.05). Moreover, the measured Tei Index values confirmed significant post-infarction impairment of the global cardiac function (basal = 0.46±0.07, 7d = 0.55±0.08, 14 d = 0.57±0.06, 30 d = 0.54±0.06, 60 d = 0.54±0.07, 90 d = 0.57±0.08; p<0.01). CONCLUSIONS/SIGNIFICANCE In summary, we have performed a complete characterization of LV post-infarction remodeling in a DBA/2J mouse model of MI, using parameters adapted to the particular characteristics of the model In the future, this well characterized model will be used in both investigative and pharmacological studies that require accurate quantitative monitoring of cardiac recovery after myocardial infarction.
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Affiliation(s)
- Carolina Benavides-Vallve
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - David Corbacho
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - Olalla Iglesias-Garcia
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - Beatriz Pelacho
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - Edurne Albiasu
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - Sara Castaño
- Cardiology Department, Clínica Universidad de Navarra, Pamplona, Navarra, Spain
| | - Arrate Muñoz-Barrutia
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - Felipe Prosper
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
| | - Carlos Ortiz-de-Solorzano
- Imaging Unit, Fundación para la Investigación Médica Aplicada, University of Navarra, Pamplona, Navarra, Spain
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13
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Constantinesco A, Choquet P, Goetz C, Monassier L. PET, SPECT, CT, and MRI in Mouse Cardiac Phenotyping: An Overview. ACTA ACUST UNITED AC 2012; 2:129-44. [DOI: 10.1002/9780470942390.mo110225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- André Constantinesco
- Laboratoire d'Imagerie Préclinique, Service de Biophysique et Médecine Nucléaire, Hôpitaux Universitaires de Strasbourg; Strasbourg France
| | - Philippe Choquet
- Laboratoire d'Imagerie Préclinique, Service de Biophysique et Médecine Nucléaire, Hôpitaux Universitaires de Strasbourg; Strasbourg France
| | - Christian Goetz
- Laboratoire d'Imagerie Préclinique, Service de Biophysique et Médecine Nucléaire, Hôpitaux Universitaires de Strasbourg; Strasbourg France
| | - Laurent Monassier
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Université de Strasbourg; Strasbourg France
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Image-derived input function from cardiac gated maximum a posteriori reconstructed PET images in mice. Mol Imaging Biol 2011; 13:342-7. [PMID: 20521133 DOI: 10.1007/s11307-010-0347-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE The purpose of this study was to determine if accurate image-derived input functions (IDIF) can be measured from cardiac gated positron emission tomography (PET) images reconstructed using ordered subset expectation maximization-maximum a posteriori (OSEM-MAP) without further correction. PROCEDURES IDIFs from the left ventricle were measured from cardiac gated PET images reconstructed using OSEM-MAP with computed tomography (CT)-based attenuation correction for five C57/BL6 mice. The accuracy of the IDIF was tested against blood samples using Bland-Altman analysis. RESULTS Image-derived blood radioactivity concentration values were not significantly different from sampled blood values at two late time points as determined by a paired t test (P = 0.97). Bland-Altman analysis revealed a mean difference of 0.06 μCi/ml (1%). Using kinetic analysis, the mean myocardial 2-deoxy-2-[(18)F]fluoro-D-glucose uptake rate constant based on the IDIF was comparable to values reported in the literature based on physical blood sampling. CONCLUSIONS Accurate IDIFs can be obtained non-invasively. Although reconstruction times are increased, no further spillover corrections are necessary for IDIFs derived from gated, OSEM-MAP reconstructed images with attenuation correction.
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Boswell CA, Ferl GZ, Mundo EE, Schweiger MG, Marik J, Reich MP, Theil FP, Fielder PJ, Khawli LA. Development and evaluation of a novel method for preclinical measurement of tissue vascular volume. Mol Pharm 2010; 7:1848-57. [PMID: 20704296 DOI: 10.1021/mp100183k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Identification of clinically predictive models of disposition kinetics for antibody therapeutics is an ongoing pursuit in drug development. To encourage translation of drug candidates from early research to clinical trials, clinical diagnostic agents may be used to characterize antibody disposition in physiologically relevant preclinical models. TechneScan PYP was employed to measure tissue vascular volumes (V(v)) in healthy mice. Two methods of red blood cell (RBC) labeling were compared: a direct in vivo method that is analogous to a clinical blood pool imaging protocol, and an indirect method in which radiolabeled blood was transfused from donor mice into recipient mice. The indirect method gave higher precision in RBC labeling yields, lower V(v) values in most tissues, and lower (99m)Tc uptake in kidneys and bladder by single photon emission computed tomographic (SPECT) imaging relative to the direct method. Furthermore, the relative influence of each method on the calculated area under the first 7 days of the concentration-time curve (AUC(0-7)) of an IgG in nude mice was assessed using a physiologically based pharmacokinetic model. The model was sensitive to the source of V(v) values, whether obtained from the literature or measured by either method, when used to predict experimental AUC(0-7) values for radiolabeled trastuzumab in healthy murine tissues. In summary, a novel indirect method for preclinical determination of V(v) offered higher precision in RBC labeling efficiency and lower renal uptake of (99m)Tc than the direct method. In addition, these observations emphasize the importance of obtaining accurate physiological parameter values for modeling antibody uptake.
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Affiliation(s)
- C Andrew Boswell
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Genentech Research and Early Development, South San Francisco, CA 94080, USA
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16
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Wollenweber T, Zach C, Rischpler C, Fischer R, Nowak S, Nekolla SG, Gröbner M, Ubleis C, Assmann G, Müller-Höcker J, La Fougére C, Böning G, Cumming P, Franz WM, Hacker M. Myocardial perfusion imaging is feasible for infarct size quantification in mice using a clinical single-photon emission computed tomography system equipped with pinhole collimators. Mol Imaging Biol 2009; 12:427-34. [PMID: 19937392 DOI: 10.1007/s11307-009-0281-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 08/28/2009] [Accepted: 10/09/2009] [Indexed: 02/06/2023]
Abstract
INTRODUCTION The aim of this study is to evaluate a non-invasive method for measuring myocardial perfusion defect size in mice using a clinical single-photon emission computed tomography system equipped with pinhole collimators (pinhole SPECT). MATERIALS AND METHODS Thirty days after ligation of the left anterior descending coronary artery, 13 mice (C57BL/6J) were imaged following intravenous injection of 370 MBq [99mTc]sestamibi. Eight control mice without myocardial infarction were likewise investigated. Image quality optimization had been achieved by repeated scanning of a multiple point phantom, with varying zoom factors, number of projection angles, and pinhole diameter. Volumetric sampling was used to generate polar maps, in which intensity was normalized to that of a standard septal region of interest (ROI), which was set at 100%. Receiver operating characteristic analyses were performed to define an optimal threshold as compared to histologically measured defect sizes, which were considered as gold standard. RESULTS A spatial resolution of 1.9 mm was achieved using a pinhole diameter of 0.5 mm, a zoom factor of 2, and 6 degrees projection angles. Histological results were best reproduced by a 60% threshold relative to the septal reference ROI. By applying this threshold, SPECT perfusion defect sizes revealed very high correlation to the histological results (R(2) = 0.867) with excellent intra- and interobserver reproducibility (intraclass correlation coefficients of 0.84 and 0.82). CONCLUSIONS We achieved a spatial resolution of 1.9 mm in myocardial perfusion imaging in mice using a clinical SPECT system mounted with pinhole collimators. Compared to a histological gold standard, the infarct sizes were accurately estimated, indicating that this method shows promise to monitor experimental cardiac interventions in mice.
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Affiliation(s)
- Tim Wollenweber
- Department of Nuclear Medicine, University of Munich, Munich, Germany
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An N-ethyl-N-nitrosourea mutagenesis recessive screen identifies two candidate regions for murine cardiomyopathy that map to chromosomes 1 and 15. Mamm Genome 2009; 20:296-304. [PMID: 19387734 DOI: 10.1007/s00335-009-9184-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 03/18/2009] [Indexed: 10/20/2022]
Abstract
N-ethyl-N-nitrosourea (ENU) mutagenesis screens have been successful for identifying genes that affect important biological processes and diseases. However, for heart-related phenotypes, these screens have been employed exclusively for developmental phenotypes, and to date no adult cardiomyopathy-causing genes have been discovered through a mutagenesis screen. To identify novel disease-causing and disease-modifying genes for cardiomyopathy, we performed an ENU recessive mutagenesis screen in adult mice. Using noninvasive echocardiography to screen for abnormalities in cardiac function, we identified a heritable cardiomyopathic phenotype in two families. To identify the chromosomal regions where the mutations are localized, we used a single nucleotide polymorphism (SNP) panel for genetic mapping of mouse mutations. This panel provided whole-genome linkage information and identified the mutagenized candidate regions at the proximal end of chromosome 1 (family EN1), and at the distal end of chromosome 15 (family EN25). We have identified 94 affected mice in family EN1 and have narrowed the candidate interval to 1 Mb. We have identified 20 affected mice in family EN25 and have narrowed the candidate interval to 12 Mb. The identification of the genes responsible for the observed phenotype in these families will be strong candidates for disease-causing or disease-modifying genes in patients with heart failure.
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Wängler B, Quandt G, Iovkova L, Schirrmacher E, Wängler C, Boening G, Hacker M, Schmoeckel M, Jurkschat K, Bartenstein P, Schirrmacher R. Kit-like 18F-labeling of proteins: synthesis of 4-(di-tert-butyl[18F]fluorosilyl)benzenethiol (Si[18F]FA-SH) labeled rat serum albumin for blood pool imaging with PET. Bioconjug Chem 2009; 20:317-21. [PMID: 19132825 DOI: 10.1021/bc800413g] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Radiosyntheses of 18F-radiopharmaceuticals for positron emission tomography (PET) normally require an extraordinarily high effort of technical equipment and specially trained personnel. We recently reported a novel method for the introduction of fluorine-18 into peptides for PET-imaging based on silicon-18F-chemistry (SiFA technique). We herewith introduce the first SiFA-based Kit-like radio-fluorination of a protein (rat serum albumin,RSA) and demonstrate its usefulness for in vivo imaging with microPET in normal rats as well as in a rat heterotropic transplanted heart model. As a labeling agent, we prepared 4-(di-tert-butyl[18F]fluorosilyl)benzenethiol (Si[18F]FASH)by simple isotopic exchange in 40-60% radiochemical yield (RCY) and coupled it directly to a Sulfo-SMCC derivatized RSA in an overall RCY of 12% within 20-30 min. The technically simple labeling procedure does not require any elaborated purification procedures and is a straightforward example of a successful application of Si-18F chemistry for in vivo imaging with PET.
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Affiliation(s)
- Björn Wängler
- Department of Nuclear Medicine, Hospital of the Ludwig-Maximilians-University, Munich, Germany.
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Stegger L, Heijman E, Schäfers KP, Nicolay K, Schäfers MA, Strijkers GJ. Quantification of Left Ventricular Volumes and Ejection Fraction in Mice Using PET, Compared with MRI. J Nucl Med 2008; 50:132-8. [DOI: 10.2967/jnumed.108.056051] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Assessment of right and left ventricular function in healthy mice by blood-pool pinhole gated SPECT. C R Biol 2008; 331:637-47. [PMID: 18722982 DOI: 10.1016/j.crvi.2008.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Accepted: 06/03/2008] [Indexed: 11/20/2022]
Abstract
The feasibility of blood-pool pinhole ECG gated SPECT was investigated in healthy mice to assess right and left ventricular function analysis. Anaesthetized (isoflurane 1-1.5%) adult CD1 mice (n=11) were analyzed after intravenous administration of 0.2 ml of 550 MBq of (99m)Tc human albumin. For blood-pool gated SPECT imaging, 48 ventral step and shoot projections with eight time bins per RR over 180 degrees with 64 x 64 word images were acquired with a small animal gamma camera equipped with a pinhole collimator of 12 cm in focal length and 1.5 mm in diameter. For appropriate segmentation of right and left ventricular volumes, a 4D Fourier analysis was performed after reconstruction and reorientation of blood-pool images with a voxel size of 0.55 x 0.55 x 0.55 mm(3). Average right and left ejection fractions were respectively 52+/-4.7% and 65+/-5.2%. Right end diastolic and end systolic volumes were significantly higher compared with the corresponding left ventricular volumes (P<0.0001 each). A linear correlation between right and left stroke volumes (r=0.9, P<0.0001) was obtained and right and left cardiac outputs were not significantly different 14.2+/-1.9 and 14.1+/-2 ml/min, respectively.
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