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Zaman RT, Kosuge H, Carpenter C, Sun C, McConnell MV, Xing L. Scintillating balloon-enabled fiber-optic system for radionuclide imaging of atherosclerotic plaques. J Nucl Med 2015; 56:771-7. [PMID: 25858046 DOI: 10.2967/jnumed.114.153239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/18/2015] [Indexed: 01/28/2023] Open
Abstract
UNLABELLED Atherosclerosis underlies coronary artery disease, the leading cause of death in the United States and worldwide. Detection of coronary plaque inflammation remains challenging. In this study, we developed a scintillating balloon-enabled fiber-optic radionuclide imaging (SBRI) system to improve the sensitivity and resolution of plaque imaging using (18)F-FDG, a marker of vascular inflammation, and tested it in a murine model. METHODS The fiber-optic system uses a Complementary Metal-Oxide Silicon (CMOS) camera with a distal ferrule terminated with a wide-angle lens. The novelty of this system is a scintillating balloon in the front of the wide-angle lens to image light from the decay of (18)F-FDG emission signal. To identify the optimal scintillating materials with respect to resolution, we calculated the modulation transfer function of yttrium-aluminum-garnet doped with cerium, anthracene, and calcium fluoride doped with europium (CaF2:Eu) phosphors using an edge pattern and a thin-line optical phantom. The scintillating balloon was then fabricated from 10 mL of silicone RTV catalyst mixed with 1 mL of base and 50 mg of CaF2:Eu per mL. The addition of a lutetium oxyorthosilicate scintillating crystal (500 μm thick) to the balloon was also investigated. The SBRI system was tested in a murine atherosclerosis model: carotid-ligated mice (n = 5) were injected with (18)F-FDG, followed by ex vivo imaging of the macrophage-rich carotid plaques and nonligated controls. Confirmatory imaging of carotid plaques and controls was also performed by an external optical imaging system and autoradiography. RESULTS Analyses of the different phosphors showed that CaF2:Eu enabled the best resolution of 1.2 μm. The SBRI system detected almost a 4-fold-higher radioluminescence signal from the ligated left carotid artery than the nonligated right carotid: 1.63 × 10(2) ± 4.01 × 10(1) vs. 4.21 × 10(1) ± 2.09 × 10(0) (photon counts), P = 0.006. We found no significant benefit to adding a scintillating crystal to the balloon: 1.65 × 10(2) ± 4.07 × 10(1) vs. 4.44 × 10(1) ± 2.17 × 10(0) (photon counts), P = 0.005. Both external optical imaging and autoradiography confirmed the high signal from the (18)F-FDG in carotid plaques versus controls. CONCLUSION This SBRI system provides high-resolution and sensitive detection of (18)F-FDG uptake by murine atherosclerotic plaques.
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Affiliation(s)
- Raiyan T Zaman
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California Division of Radiation Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; and
| | - Hisanori Kosuge
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | | | - Conroy Sun
- Division of Radiation Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; and
| | - Michael V McConnell
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Lei Xing
- Division of Radiation Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; and
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Busold S, Philipp K, Otten A, Roth M. Image plate characterization and absolute calibration to low kilo-electron-volt electrons. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:113306. [PMID: 25430109 DOI: 10.1063/1.4902321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report on the characterization of an image plate and its absolute calibration to electrons in the low keV energy range (1-30 keV). In our case, an Agfa MD4.0 without protection layer was used in combination with a Fuji FLA7000 scanner. The calibration data are compared to other published data and a consistent picture of the sensitivity of image plates to electrons is obtained, which suggests a validity of the obtained calibration up to 100 keV.
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Affiliation(s)
- S Busold
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany
| | - K Philipp
- Institus für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
| | - A Otten
- Institus für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
| | - M Roth
- Institus für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt, Germany
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Zaman RT, Kosuge H, Pratx G, Carpenter C, Xing L, McConnell MV. Fiber-optic system for dual-modality imaging of glucose probes 18F-FDG and 6-NBDG in atherosclerotic plaques. PLoS One 2014; 9:e108108. [PMID: 25233472 PMCID: PMC4169475 DOI: 10.1371/journal.pone.0108108] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 08/19/2014] [Indexed: 12/02/2022] Open
Abstract
Background Atherosclerosis is a progressive inflammatory condition that underlies coronary artery disease (CAD)–the leading cause of death in the United States. Thus, the ultimate goal of this research is to advance our understanding of human CAD by improving the characterization of metabolically active vulnerable plaques within the coronary arteries using a novel catheter-based imaging system. The aims of this study include (1) developing a novel fiber-optic imaging system with a scintillator to detect both 18F and fluorescent glucose probes, and (2) validating the system on ex vivo murine plaques. Methods A novel design implements a flexible fiber-optic catheter consisting of both a radio-luminescence and a fluorescence imaging system to detect radionuclide 18F-fluorodeoxyglucose (18F-FDG) and the fluorescent analog 6-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-6-Deoxyglucose (6-NBDG), respectively. Murine macrophage-rich atherosclerotic carotid plaques were imaged ex vivo after intravenous delivery of 18F-FDG or 6-NBDG. Confirmatory optical imaging by IVIS-200 and autoradiography were also performed. Results Our fiber-optic imaging system successfully visualized both 18F-FDG and 6-NBDG probes in atherosclerotic plaques. For 18F-FDG, the ligated left carotid arteries (LCs) exhibited 4.9-fold higher radioluminescence signal intensity compared to the non-ligated right carotid arteries (RCs) (2.6×104±1.4×103 vs. 5.4×103±1.3×103 A.U., P = 0.008). Similarly, for 6-NBDG, the ligated LCs emitted 4.3-fold brighter fluorescent signals than the control RCs (1.6×102±2.7×101 vs. 3.8×101±5.9 A.U., P = 0.002). The higher uptake of both 18F-FDG and 6-NBDG in ligated LCs were confirmed with the IVIS-200 system. Autoradiography further verified the higher uptake of 18F-FDG by the LCs. Conclusions This novel fiber-optic imaging system was sensitive to both radionuclide and fluorescent glucose probes taken up by murine atherosclerotic plaques. In addition, 6-NBDG is a promising novel fluorescent probe for detecting macrophage-rich atherosclerotic plaques.
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Affiliation(s)
- Raiyan T. Zaman
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Division of Radiation Physics, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
| | - Hisanori Kosuge
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Guillem Pratx
- Division of Radiation Physics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Colin Carpenter
- Division of Radiation Physics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Lei Xing
- Division of Radiation Physics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Michael V. McConnell
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States of America
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Shikhaliev PM, Petrek P, Matthews KL, Fritz SG, Bujenovic LS, Xu T. Intravascular imaging with a storage phosphor detector. Phys Med Biol 2010; 55:2841-61. [DOI: 10.1088/0031-9155/55/10/004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Qureshi AI, Taylor RA. Research priorities for intracranial atherosclerotic diseases. J Neuroimaging 2010; 19 Suppl 1:39S-42S. [PMID: 19807858 DOI: 10.1111/j.1552-6569.2009.00422.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The current review summarizes the characteristics of existing experimental models for intracranial atherosclerosis in rabbits, pigs, and dogs with potential implications for research. New methodologies for understanding plaque morphology, and plaque quantitation and its prognostic implications are important for risk stratification in regards to ischemic events and lesion progression. A potential treatment strategy for intracranial atherosclerotic disease may be aimed at medical therapies that induce plaque regression. The treatment with statins to stabilize and/or promote plaque regression of intracranial atherosclerotic lesions is largely inferred from data in the coronary literature. In patients with multisegmented intracranial atherosclerotic diseases with no other therapeutic option, angiogenic growth factors may represent a new venue.
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Affiliation(s)
- Adnan I Qureshi
- Zeenat Qureshi Stroke Research Center, Department of Neurology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Qureshi AI, Feldmann E, Gomez CR, Johnston SC, Kasner SE, Quick DC, Rasmussen PA, Suri MFK, Taylor RA, Zaidat OO. Intracranial atherosclerotic disease: an update. Ann Neurol 2010; 66:730-8. [PMID: 20035502 DOI: 10.1002/ana.21768] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The consensus conference on intracranial atherosclerosis provides a comprehensive review of the existing literature relevant to the epidemiology, diagnosis, prevention, and treatment of intracranial atherosclerosis, and identifies principles of management and research priorities. Patients who have suffered a stroke or transient ischemic attack attributed to stenosis (50-99%) of a major intracranial artery face a 12 to 14% risk for subsequent stroke during the 2-year period after the initial ischemic event, despite treatment with antithrombotic medications. The annual risk for subsequent stroke may exceed 20% in high-risk groups. In patients with intracranial atherosclerotic disease, short-term and long-term anticoagulation is not superior to antiplatelet treatment. Overall, the subgroup analyses from randomized trials provide evidence about benefit of aggressive atherogenic risk factor management. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic intracranial atherosclerotic disease, particularly those with high-grade stenosis with recurrent ischemic symptoms, medication failure, or both. A multicenter randomized trial is currently under way to compare stent placement with intense medical management for patients with high-grade symptomatic intracranial atherosclerotic disease.
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Affiliation(s)
- Adnan I Qureshi
- Zeenat Qureshi Stroke Research Center, University of Minnesota, Minneapolis, MN 55455, USA.
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Abstract
Symptomatic intracranial arterial stenosis carries one of the highest rates of recurrent stroke (10%-20% per year) despite antithrombotic therapy. Stroke prevention strategies for intracranial atherosclerotic disease follow the guidelines for secondary stroke prevention that target atherogenic risk factors. These include following standard stroke prevention guidelines of weight loss for overweight patients, moderate physical exercise (at least 30 minutes most days), cessation of cigarette smoking, and a low-fat, low-cholesterol diet. Pharmacologic treatments include antiplatelet agents, statins, blood sugar control for diabetics, and antihypertensive medications. Goals may include low-density lipoprotein cholesterol less than 100 mg/dL (< 70 mg/dL in high-risk patients). The absolute blood pressure reduction target is uncertain, but average long-term reductions of 10/5 mm Hg are recommended. Angioplasty with stent placement for the treatment of symptomatic severe intracranial stenosis (>/= 70%) is currently being evaluated in a phase 3 randomized controlled trial. It is unclear whether angioplasty with stent placement is superior to angioplasty alone for the treatment of intracranial stenosis, so both endovascular methods are currently acceptable. Complication and success rates for intracranial angioplasty and stent placement are highly variable, so the widespread application of this procedure is generally not recommended outside of clinical trials and experienced centers.
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Riou LM, Broisat A, Dimastromatteo J, Pons G, Fagret D, Ghezzi C. Pre-clinical and clinical evaluation of nuclear tracers for the molecular imaging of vulnerable atherosclerosis: an overview. Curr Med Chem 2009; 16:1499-511. [PMID: 19355903 DOI: 10.2174/092986709787909596] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cardiovascular diseases (CVD) are the leading cause of mortality worldwide. Despite major advances in the treatment of CVD, a high proportion of CVD victims die suddenly while being apparently healthy, the great majority of these accidents being due to the rupture or erosion of a vulnerable coronary atherosclerotic plaque. A non-invasive imaging methodology allowing the early detection of vulnerable atherosclerotic plaques in selected individuals prior to the occurrence of any symptom would therefore be of great public health benefit. Nuclear imaging could allow the identification of vulnerable patients by non-invasive in vivo scintigraphic imaging following administration of a radiolabeled tracer. The purpose of this review is to provide an overview of radiotracers that have been recently evaluated for the detection of vulnerable plaques together with the biological rationale that initiated their development. Radiotracers targeted at the inflammatory process seem particularly relevant and promising. Recently, macrophage targeting allowed the experimental in vivo detection of atherosclerosis using either SPECT or PET. A few tracers have also been evaluated clinically. Targeting of apoptosis and macrophage metabolism both allowed the imaging of vulnerable plaques in carotid vessels of patients. However, nuclear imaging of vulnerable plaques at the level of coronary arteries remains challenging, mostly because of their small size and their vicinity with unbound circulating tracer. The experimental and pilot clinical studies reviewed in the present paper represent a fundamental step prior to the evaluation of the efficacy of any selected tracer for the early, non-invasive detection of vulnerable patients.
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Affiliation(s)
- L M Riou
- INSERM, U877, Radiopharmaceutiques Biocliniques, Faculté de Médecine de Grenoble, F-38700, La tronche, France.
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Gössl M, Versari D, Hildebrandt H, Mannheim D, Olson ML, Lerman LO, Lerman A. Vulnerable plaque: detection and management. Med Clin North Am 2007; 91:573-601; ix-x. [PMID: 17640537 DOI: 10.1016/j.mcna.2007.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Because most myocardial infarctions result from the rupture of a plaque that did not significantly compromise the coronary lumen before the event, experts widely accept that the morphology, composition, and degree of inflammation of a coronary atherosclerotic plaque is more important than the degree of luminal stenosis. Two depicting examples are the concentric, calcified lesion that shows significant luminal stenosis but is stable because of the stabilizing clasp of calcification. In contrast, a smaller but inflamed thin fibrous cap atheroma with a big lipid/necrotic core may rupture and cause an immediate fatal coronary occlusion.
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Affiliation(s)
- Mario Gössl
- Division of Cardiovascular Diseases, Mayo Clinic, Mary Brigh 4-523, 200 First Street SW, Rochester, MN 55905, USA
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