1
|
Nekolla SG, Rischpler C, Higuchi T. Preclinical Imaging of Cardiovascular Disesase. Semin Nucl Med 2023; 53:586-598. [PMID: 37268498 DOI: 10.1053/j.semnuclmed.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 06/04/2023]
Abstract
Noninvasive imaging techniques, such as SPECT, PET, CT, echocardiography, or MRI, have become essential in cardiovascular research. They allow for the evaluation of biological processes in vivo without the need for invasive procedures. Nuclear imaging methods, such as SPECT and PET, offer numerous advantages, including high sensitivity, reliable quantification, and the potential for serial imaging. Modern SPECT and PET imaging systems, equipped with CT and MRI components in order to get access to morphological information with high spatial resolution, are capable of imaging a wide range of established and innovative agents in both preclinical and clinical settings. This review highlights the utility of SPECT and PET imaging as powerful tools for translational research in cardiology. By incorporating these techniques into a well-defined workflow- similar to those used in clinical imaging- the concept of "bench to bedside" can be effectively implemented.
Collapse
Affiliation(s)
- Stephan G Nekolla
- Nuklearmedizinische Klinik der TU München, Munich, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany.
| | | | - Takahiro Higuchi
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany; Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| |
Collapse
|
2
|
Neumann KD, Broshek DK, Newman BT, Druzgal TJ, Kundu BK, Resch JE. Concussion: Beyond the Cascade. Cells 2023; 12:2128. [PMID: 37681861 PMCID: PMC10487087 DOI: 10.3390/cells12172128] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Sport concussion affects millions of athletes each year at all levels of sport. Increasing evidence demonstrates clinical and physiological recovery are becoming more divergent definitions, as evidenced by several studies examining blood-based biomarkers of inflammation and imaging studies of the central nervous system (CNS). Recent studies have shown elevated microglial activation in the CNS in active and retired American football players, as well as in active collegiate athletes who were diagnosed with a concussion and returned to sport. These data are supportive of discordance in clinical symptomology and the inflammatory response in the CNS upon symptom resolution. In this review, we will summarize recent advances in the understanding of the inflammatory response associated with sport concussion and broader mild traumatic brain injury, as well as provide an outlook for important research questions to better align clinical and physiological recovery.
Collapse
Affiliation(s)
- Kiel D. Neumann
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA;
| | - Donna K. Broshek
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA 22903, USA;
| | - Benjamin T. Newman
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - T. Jason Druzgal
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - Bijoy K. Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - Jacob E. Resch
- Department of Kinesiology, University of Virginia, Charlottesville, VA 22903, USA
| |
Collapse
|
3
|
Li J, Minczuk K, Huang Q, Kemp BA, Howell NL, Chordia MD, Roy RJ, Patrie JT, Qureshi Z, Kramer CM, Epstein FH, Carey RM, Kundu BK, Keller SR. Progressive Cardiac Metabolic Defects Accompany Diastolic and Severe Systolic Dysfunction in Spontaneously Hypertensive Rat Hearts. J Am Heart Assoc 2023; 12:e026950. [PMID: 37183873 PMCID: PMC10227297 DOI: 10.1161/jaha.122.026950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 04/14/2023] [Indexed: 05/16/2023]
Abstract
Background Cardiac metabolic abnormalities are present in heart failure. Few studies have followed metabolic changes accompanying diastolic and systolic heart failure in the same model. We examined metabolic changes during the development of diastolic and severe systolic dysfunction in spontaneously hypertensive rats (SHR). Methods and Results We serially measured myocardial glucose uptake rates with dynamic 2-[18F] fluoro-2-deoxy-d-glucose positron emission tomography in vivo in 9-, 12-, and 18-month-old SHR and Wistar Kyoto rats. Cardiac magnetic resonance imaging determined systolic function (ejection fraction) and diastolic function (isovolumetric relaxation time) and left ventricular mass in the same rats. Cardiac metabolomics was performed at 12 and 18 months in separate rats. At 12 months, SHR hearts, compared with Wistar Kyoto hearts, demonstrated increased isovolumetric relaxation time and slightly reduced ejection fraction indicating diastolic and mild systolic dysfunction, respectively, and higher (versus 9-month-old SHR decreasing) 2-[18F] fluoro-2-deoxy-d-glucose uptake rates (Ki). At 18 months, only few SHR hearts maintained similar abnormalities as 12-month-old SHR, while most exhibited severe systolic dysfunction, worsening diastolic function, and markedly reduced 2-[18F] fluoro-2-deoxy-d-glucose uptake rates. Left ventricular mass normalized to body weight was elevated in SHR, more pronounced with severe systolic dysfunction. Cardiac metabolite changes differed between SHR hearts at 12 and 18 months, indicating progressive defects in fatty acid, glucose, branched chain amino acid, and ketone body metabolism. Conclusions Diastolic and severe systolic dysfunction in SHR are associated with decreasing cardiac glucose uptake, and progressive abnormalities in metabolite profiles. Whether and which metabolic changes trigger progressive heart failure needs to be established.
Collapse
Affiliation(s)
- Jie Li
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
| | - Krzysztof Minczuk
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
- Department of Experimental Physiology and PathophysiologyMedical University of BiałystokBialystokPoland
| | - Qiao Huang
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
| | - Brandon A. Kemp
- Department of Medicine, Division of Endocrinology and MetabolismUniversity of VirginiaCharlottesvilleVA
| | - Nancy L. Howell
- Department of Medicine, Division of Endocrinology and MetabolismUniversity of VirginiaCharlottesvilleVA
| | - Mahendra D. Chordia
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
| | - R. Jack Roy
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
| | - James T. Patrie
- Department of Public Health SciencesUniversity of VirginiaCharlottesvilleVA
| | - Zoraiz Qureshi
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
- Department of Computer ScienceUniversity of VirginiaCharlottesvilleVA
| | - Christopher M. Kramer
- Department of Medicine, Cardiovascular DivisionUniversity of VirginiaCharlottesvilleVA
| | | | - Robert M. Carey
- Department of Medicine, Division of Endocrinology and MetabolismUniversity of VirginiaCharlottesvilleVA
| | - Bijoy K. Kundu
- Department of Radiology and Medical ImagingUniversity of VirginiaCharlottesvilleVA
- Department of Biomedical EngineeringUniversity of VirginiaCharlottesvilleVA
- Cardiovascular Research CenterUniversity of VirginiaCharlottesvilleVA
| | - Susanna R. Keller
- Department of Medicine, Division of Endocrinology and MetabolismUniversity of VirginiaCharlottesvilleVA
| |
Collapse
|
4
|
Iker Etchegaray J, Kelley S, Penberthy K, Karvelyte L, Nagasaka Y, Gasperino S, Paul S, Seshadri V, Raymond M, Marco AR, Pinney J, Stremska M, Barron B, Lucas C, Wase N, Fan Y, Unanue E, Kundu B, Burstyn-Cohen T, Perry J, Ambati J, Ravichandran KS. Phagocytosis in the retina promotes local insulin production in the eye. Nat Metab 2023; 5:207-218. [PMID: 36732622 PMCID: PMC10457724 DOI: 10.1038/s42255-022-00728-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 12/16/2022] [Indexed: 02/04/2023]
Abstract
The retina is highly metabolically active, relying on glucose uptake and aerobic glycolysis. Situated in close contact to photoreceptors, a key function of cells in the retinal pigment epithelium (RPE) is phagocytosis of damaged photoreceptor outer segments (POS). Here we identify RPE as a local source of insulin in the eye that is stimulated by POS phagocytosis. We show that Ins2 messenger RNA and insulin protein are produced by RPE cells and that this production correlates with RPE phagocytosis of POS. Genetic deletion of phagocytic receptors ('loss of function') reduces Ins2, whereas increasing the levels of the phagocytic receptor MerTK ('gain of function') increases Ins2 production in male mice. Contrary to pancreas-derived systemic insulin, RPE-derived local insulin is stimulated during starvation, which also increases RPE phagocytosis. Global or RPE-specific Ins2 gene deletion decreases retinal glucose uptake in starved male mice, dysregulates retinal physiology, causes defects in phototransduction and exacerbates photoreceptor loss in a mouse model of retinitis pigmentosa. Collectively, these data identify RPE cells as a phagocytosis-induced local source of insulin in the retina, with the potential to influence retinal physiology and disease.
Collapse
Affiliation(s)
- J Iker Etchegaray
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Shannon Kelley
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kristen Penberthy
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Laura Karvelyte
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Yosuke Nagasaka
- Center for Advanced Vision Science, University of Virginia, Charlottesville, VA, USA
| | - Sofia Gasperino
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Soumen Paul
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Vikram Seshadri
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Michael Raymond
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Ana Royo Marco
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Jonathan Pinney
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Marta Stremska
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Brady Barron
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Christopher Lucas
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
- University of Edinburgh, Edinburgh, UK
| | - Nishikant Wase
- Biomolecular Analysis Facility, University of Virginia, Charlottesville, VA, USA
| | - Yong Fan
- Drexel University, Philadelphia, PA, USA
| | - Emil Unanue
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Bijoy Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Tal Burstyn-Cohen
- Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Justin Perry
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jayakrishna Ambati
- Center for Advanced Vision Science, University of Virginia, Charlottesville, VA, USA
- Ophthalmology, University of Virginia, Charlottesville, VA, USA
| | - Kodi S Ravichandran
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.
- Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel.
- VIB/UGent Inflammation Research Centre, and Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
| |
Collapse
|
5
|
Furcea DM, Agrigoroaie L, Mihai CT, Gardikiotis I, Dodi G, Stanciu GD, Solcan C, Beschea Chiriac SI, Guțu MM, Ștefănescu C. 18F-FDG PET/MRI Imaging in a Preclinical Rat Model of Cardiorenal Syndrome-An Exploratory Study. Int J Mol Sci 2022; 23:ijms232315409. [PMID: 36499736 PMCID: PMC9738874 DOI: 10.3390/ijms232315409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Cardiorenal syndrome (CRS) denotes the bidirectional interaction of chronic kidney disease and heart failure with an adverse prognosis but with a limited understanding of its pathogenesis. This study correlates biochemical blood markers, histopathological and immunohistochemistry features, and 2-deoxy-2-fluoro-D-glucose positron emission tomography (18F-FDG PET) metabolic data in low-dose doxorubicin-induced heart failure, cardiorenal syndrome, and renocardiac syndrome induced on Wistar male rats. To our knowledge, this is the first study that investigates the underlying mechanisms for CRS progression in rats using 18F-FDG PET. Clinical, metabolic cage monitoring, biochemistry, histopathology, and immunohistochemistry combined with PET/MRI (magnetic resonance imaging) data acquisition at distinct points in the disease progression were employed for this study in order to elucidate the available evidence of organ crosstalk between the heart and kidneys. In our CRS model, we found that chronic treatment with low-dose doxorubicin followed by acute 5/6 nephrectomy incurred the highest mortality among the study groups, while the model for renocardiac syndrome resulted in moderate-to-high mortality. 18F-FDG PET imaging evidenced the doxorubicin cardiotoxicity with vascular alterations, normal kidney development damage, and impaired function. Given the fact that standard clinical markers were insensitive to early renal injury, we believe that the decreasing values of the 18F-FDG PET-derived renal marker across the groups and, compared with their age-matched controls, along with the uniform distribution seen in healthy developing rats, could have a potential diagnostic and prognostic yield in cardiorenal syndrome.
Collapse
Affiliation(s)
- Dan Mihai Furcea
- Department of Nuclear Medicine, Sf. Spiridon University Emergency Hospital, 700111 Iasi, Romania
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700454 Iasi, Romania
| | - Laurențiu Agrigoroaie
- Department of Nuclear Medicine, Sf. Spiridon University Emergency Hospital, 700111 Iasi, Romania
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700454 Iasi, Romania
| | - Cosmin-T. Mihai
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700454 Iasi, Romania
| | - Ioannis Gardikiotis
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700454 Iasi, Romania
| | - Gianina Dodi
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700454 Iasi, Romania
- Correspondence:
| | - Gabriela D. Stanciu
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700454 Iasi, Romania
| | - Carmen Solcan
- Faculty of Veterinary Medicine, Ion Ionescu de la Brad University of Agricultural Sciences and Veterinary Medicine, 700490 Iasi, Romania
| | - Sorin I. Beschea Chiriac
- Faculty of Veterinary Medicine, Ion Ionescu de la Brad University of Agricultural Sciences and Veterinary Medicine, 700490 Iasi, Romania
| | - Mihai Marius Guțu
- Department of Biophysics and Medical Physics—Nuclear Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania
| | - Cipriana Ștefănescu
- Department of Biophysics and Medical Physics—Nuclear Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 700115 Iasi, Romania
| |
Collapse
|
6
|
Quigg M, Kundu B. Dynamic FDG-PET demonstration of functional brain abnormalities. Ann Clin Transl Neurol 2022; 9:1487-1497. [PMID: 36069052 PMCID: PMC9463948 DOI: 10.1002/acn3.51546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 11/27/2022] Open
Abstract
Positron emission tomography with fluorine‐18 fluorodeoxyglucose (18F‐FDG‐PET) has been used over 3 decades to map patterns of brain glucose metabolism to evaluate normal brain function or demonstrate abnormalities of metabolism in brain disorders. Traditional PET maps patterns of absolute tracer uptake but has demonstrated shortcomings in disorders such as brain neoplasm or focal epilepsy in the ability to resolve normally from pathological tissue. In this review, we describe an alternative process of metabolic mapping, dynamic PET. This new technology quantifies the dynamics of tracer uptake and decays with the goal of improving the functional mapping of the desired metabolic activity in the target organ. We discuss technical implementation and findings of initial pilot studies in brain tumor treatment and epilepsy surgery.
Collapse
Affiliation(s)
- Mark Quigg
- Department of Neurology, University of Virginia, Charlottesville, Virginia, 22908, USA
| | - Bijoy Kundu
- Departments of Radiology & Medical Imaging and Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| |
Collapse
|
7
|
Massey JC, Seshadri V, Paul S, Mińczuk K, Molinos C, Li J, Kundu BK. Model Corrected Blood Input Function to Compute Cerebral FDG Uptake Rates From Dynamic Total-Body PET Images of Rats in vivo. Front Med (Lausanne) 2021; 8:618645. [PMID: 33898476 PMCID: PMC8058193 DOI: 10.3389/fmed.2021.618645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 02/15/2021] [Indexed: 12/17/2022] Open
Abstract
Recently, we developed a three-compartment dual-output model that incorporates spillover (SP) and partial volume (PV) corrections to simultaneously estimate the kinetic parameters and model-corrected blood input function (MCIF) from dynamic 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) images of mouse heart in vivo. In this study, we further optimized this model and utilized the estimated MCIF to compute cerebral FDG uptake rates, Ki, from dynamic total-body FDG PET images of control Wistar–Kyoto (WKY) rats and compared to those derived from arterial blood sampling in vivo. Dynamic FDG PET scans of WKY rats (n = 5), fasted for 6 h, were performed using the Albira Si Trimodal PET/SPECT/CT imager for 60 min. Arterial blood samples were collected for the entire imaging duration and then fitted to a seven-parameter function. The 60-min list mode PET data, corrected for attenuation, scatter, randoms, and decay, were reconstructed into 23 time bins. A 15-parameter dual-output model with SP and PV corrections was optimized with two cost functions to compute MCIF. A four-parameter compartment model was then used to compute cerebral Ki. The computed area under the curve (AUC) and Ki were compared to that derived from arterial blood samples. Experimental and computed AUCs were 1,893.53 ± 195.39 kBq min/cc and 1,792.65 ± 155.84 kBq min/cc, respectively (p = 0.76). Bland–Altman analysis of experimental vs. computed Ki for 35 cerebral regions in WKY rats revealed a mean difference of 0.0029 min−1 (~13.5%). Direct (AUC) and indirect (Ki) comparisons of model computations with arterial blood sampling were performed in WKY rats. AUC and the downstream cerebral FDG uptake rates compared well with that obtained using arterial blood samples. Experimental vs. computed cerebral Ki for the four super regions including cerebellum, frontal cortex, hippocampus, and striatum indicated no significant differences.
Collapse
Affiliation(s)
- James C Massey
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Vikram Seshadri
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Soumen Paul
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Krzysztof Mińczuk
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States.,Department of Experimental Physiology and Pathophysiology, Medical University of Białystok, Białystok, Poland
| | - Cesar Molinos
- Preclinical Imaging Division, Bruker Biospin, Billerica, MA, United States
| | - Jie Li
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States
| | - Bijoy K Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States.,Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States.,Cardiovascular Research Center, University of Virginia, Charlottesville, VA, United States
| |
Collapse
|
8
|
Lai Y, Wang Q, Zhou S, Xie Z, Qi J, Cherry SR, Jin M, Chi Y, Du J. H 2RSPET: a 0.5 mm resolution high-sensitivity small-animal PET scanner, a simulation study. Phys Med Biol 2021; 66:065016. [PMID: 33571980 DOI: 10.1088/1361-6560/abe558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
With the goal of developing a total-body small-animal PET system with a high spatial resolution of ∼0.5 mm and a high sensitivity >10% for mouse/rat studies, we simulated four scanners using the graphical processing unit-based Monte Carlo simulation package (gPET) and compared their performance in terms of spatial resolution and sensitivity. We also investigated the effect of depth-of-interaction (DOI) resolution on the spatial resolution. All the scanners are built upon 128 DOI encoding dual-ended readout detectors with lutetium yttrium oxyorthosilicate (LYSO) arrays arranged in 8 detector rings. The solid angle coverages of the four scanners are all ∼0.85 steradians. Each LYSO element has a cross-section of 0.44 × 0.44 mm2 and the pitch size of the LYSO arrays are all 0.5 mm. The four scanners can be divided into two groups: (1) H2RS110-C10 and H2RS110-C20 with 40 × 40 LYSO arrays, a ring diameter of 110 mm and axial length of 167 mm, and (2) H2RS160-C10 and H2RS160-C20 with 60 × 60 LYSO arrays, a diameter of 160 mm and axial length of 254 mm. C10 and C20 denote the crystal thickness of 10 and 20 mm, respectively. The simulation results show that all scanners have a spatial resolution better than 0.5 mm at the center of the field-of-view (FOV). The radial resolution strongly depends on the DOI resolution and radial offset, but not the axial resolution and tangential resolution. Comparing the C10 and C20 designs, the former provides better resolution, especially at positions away from the center of the FOV, whereas the latter has 2× higher sensitivity (∼10% versus ∼20%). This simulation study provides evidence that the 110 mm systems are a good choice for total-body mouse studies at a lower cost, whereas the 160 mm systems are suited for both total-body mouse and rat studies.
Collapse
Affiliation(s)
- Youfang Lai
- Department of Physics, University of Texas at Arlington, Arlington, TX 76019, United States of America
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Feasibility of Longitudinal Brain PET with Real-Time Arterial Input Function in Rats. Mol Imaging Biol 2020; 23:350-360. [PMID: 33201350 DOI: 10.1007/s11307-020-01556-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/18/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Preclinical dynamic brain PET studies remain hampered by the limitations related to the measurement of the arterial input function (AIF). In this regard, the use of an arterial-venous shunt is a promising method for the generation of real-time AIFs, but its application in longitudinal studies is still impeded by the cumbersome surgeries and high failure rates. We studied the feasibility and reproducibility of double arterial-venous shunt strategies for conducting longitudinal PET studies with real-time AIFs in rats. PROCEDURES We studied the feasibility of double arterial-venous shunts in rats in the right/left inguinal region and evaluated inter-animal and intra-animal AIF reproducibilities. Image-derived input function (IDIF) was also obtained for comparison. Dynamic brain FDG PET studies were conducted to estimate kinetic constants and Cerebral Metabolic Rate of Glucose (CMRglc) obtained from standard 2-tissue compartment (2TCM) and Patlak analysis. RESULTS We showed that longitudinal AIFs from double arterial-venous shunts can be obtained with very high success rate of the surgeries (88 %). Our results provided highly reproducible AIF measurements with low inter-animal variabilities (11 %) and intra-animal variabilities (5-10 %) that were included into the kinetic models, such that longitudinal rate constants and CMRglc can be efficiently estimated without bias associated to the double shunt. Our results indicated that longitudinal IDIF can be also generated without bias along time but showing higher intra-animal uncertainties. CONCLUSIONS We have demonstrated the feasibility and high reproducibility of conducting longitudinal AIF measurements and consequently accurate kinetic modeling using arterial shunt method.
Collapse
|
10
|
Li J, Minćzuk K, Massey JC, Howell NL, Roy RJ, Paul S, Patrie JT, Kramer CM, Epstein FH, Carey RM, Taegtmeyer H, Keller SR, Kundu BK. Metformin Improves Cardiac Metabolism and Function, and Prevents Left Ventricular Hypertrophy in Spontaneously Hypertensive Rats. J Am Heart Assoc 2020; 9:e015154. [PMID: 32248762 PMCID: PMC7428616 DOI: 10.1161/jaha.119.015154] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background In spontaneously hypertensive rats (SHR) we observed profound myocardial metabolic changes during early hypertension before development of cardiac dysfunction and left ventricular hypertrophy. In this study, we evaluated whether metformin improved myocardial metabolic abnormalities and simultaneously prevented contractile dysfunction and left ventricular hypertrophy in SHR. Methods and Results SHR and control Wistar–Kyoto rats were treated with metformin from 2 to 5 months of age, when SHR hearts exhibit metabolic abnormalities and develop cardiac dysfunction and left ventricular hypertrophy. We evaluated the effect of metformin on myocardial glucose uptake rates with dynamic 2‐[18F] fluoro‐2‐deoxy‐D‐glucose positron emission tomography. We used cardiac MRI in vivo to assess the effect of metformin on ejection fraction, left ventricular mass, and end‐diastolic wall thickness, and also analyzed metabolites, AMP‐activated protein kinase and mammalian target‐of‐rapamycin activities, and mean arterial blood pressure. Metformin‐treated SHR had lower mean arterial blood pressure but remained hypertensive. Cardiac glucose uptake rates, left ventricular mass/tibia length, wall thickness, and circulating free fatty acid levels decreased to normal, and ejection fraction improved in treated SHR. Hearts of treated SHR exhibited increased AMP‐activated protein kinase phosphorylation and reduced mammalian target‐of‐rapamycin activity. Cardiac metabolite profiling demonstrated that metformin decreased fatty acyl carnitines and markers of oxidative stress in SHR. Conclusions Metformin reduced blood pressure, normalized myocardial glucose uptake, prevented left ventricular hypertrophy, and improved cardiac function in SHR. Metformin may exert its effects by normalizing myocardial AMPK and mammalian target‐of‐rapamycin activities, improving fatty acid oxidation, and reducing oxidative stress. Thus, metformin may be a new treatment to prevent or ameliorate chronic hypertension–induced left ventricular hypertrophy.
Collapse
Affiliation(s)
- Jie Li
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - Krzysztof Minćzuk
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA.,Department of Experimental Physiology and Pathophysiology Medical University of Białystok Białystok Poland
| | - James C Massey
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA.,Department of Biomedical Engineering University of Virginia Charlottesville VA
| | - Nancy L Howell
- Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - R Jack Roy
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - Soumen Paul
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - James T Patrie
- Department of Public Health Sciences University of Virginia Charlottesville VA
| | | | - Frederick H Epstein
- Department of Biomedical Engineering University of Virginia Charlottesville VA
| | - Robert M Carey
- Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - Heinrich Taegtmeyer
- McGovern Medical School The University of Texas Health Science Center, Houston, TX
| | - Susanna R Keller
- Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - Bijoy K Kundu
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA.,Department of Biomedical Engineering University of Virginia Charlottesville VA.,Cardiovascular Research Center University of Virginia Charlottesville VA
| |
Collapse
|