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Akerele MI, Mushari NA, Forsythe RO, Syed M, Karakatsanis NA, Newby DE, Dweck MR, Tsoumpas C. Assessment of different quantification metrics of [ 18F]-NaF PET/CT images of patients with abdominal aortic aneurysm. J Nucl Cardiol 2022; 29:251-261. [PMID: 32557152 PMCID: PMC8873073 DOI: 10.1007/s12350-020-02220-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/26/2020] [Indexed: 01/22/2023]
Abstract
BACKGROUND We aim to assess the spill-in effect and the benefit in quantitative accuracy for [18F]-NaF PET/CT imaging of abdominal aortic aneurysms (AAA) using the background correction (BC) technique. METHODS Seventy-two datasets of patients diagnosed with AAA were reconstructed with ordered subset expectation maximization algorithm incorporating point spread function (PSF). Spill-in effect was investigated for the entire aneurysm (AAA), and part of the aneurysm excluding the region close to the bone (AAAexc). Quantifications of PSF and PSF+BC images using different thresholds (% of max. SUV in target regions-of-interest) to derive target-to-background (TBR) values (TBRmax, TBR90, TBR70 and TBR50) were compared at 3 and 10 iterations. RESULTS TBR differences were observed between AAA and AAAexc due to spill-in effect from the bone into the aneurysm. TBRmax showed the highest sensitivity to the spill-in effect while TBR50 showed the least. The spill-in effect was reduced at 10 iterations compared to 3 iterations, but at the expense of reduced contrast-to-noise ratio (CNR). TBR50 yielded the best trade-off between increased CNR and reduced spill-in effect. PSF+BC method reduced TBR sensitivity to spill-in effect, especially at 3 iterations, compared to PSF (P-value ≤ 0.05). CONCLUSION TBR50 is robust metric for reduced spill-in and increased CNR.
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Affiliation(s)
- Mercy I. Akerele
- Biomedical Imaging Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9NL UK
| | - Nouf A. Mushari
- Biomedical Imaging Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9NL UK
| | - Rachael O. Forsythe
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging Facility, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Maaz Syed
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging Facility, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Nicolas A. Karakatsanis
- Division of Radiopharmaceutical Sciences, Department of Radiology, Weil Cornell Medical College of Cornell University, New York, NY USA
- Biomedical Engineering & Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - David E. Newby
- Edinburgh Imaging Facility, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Marc R. Dweck
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging Facility, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Charalampos Tsoumpas
- Biomedical Imaging Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, LS2 9NL UK
- Biomedical Engineering & Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY USA
- Invicro, London, UK
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Al-Faham Z, Jolepalem P, Rydberg J, Wong CYO. Optimizing 18F-FDG Uptake Time Before Imaging Improves the Accuracy of PET/CT in Liver Lesions. J Nucl Med Technol 2016; 44:70-2. [PMID: 26966128 DOI: 10.2967/jnmt.115.169953] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 02/12/2016] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED (18)F-FDG PET/CT has emerged as one of the fastest-growing imaging modalities. A shorter protocol results in a lower target-to-background ratio, which can increase the challenge of identifying mildly (18)F-FDG-avid lesions and differentiating inflammatory or physiologic activity from malignant activity. The purpose of this study was to determine the delay between radiotracer injection and imaging that optimizes target-to-background ratio while maintaining counts high enough to ensure scan sensitivity. METHODS The study included 140 patients (66 male and 74 female; age range, 42-95 y) with suspected hepatic lesions as seen on an (18)F-FDG PET scan. SUV was determined as region-of-interest activity/(dose/total body weight). RESULTS The mean injected dose was 610 ± 66.6 MBq (16.5 ±1.8 mCi), with a mean glucose level of 107 ± 26.6 mg/dL (standardized to 90 mg/dL). The uptake time before imaging ranged from 61 to 158 min, with a mean of 108.8 ± 24.8 min. The P values for the correlation of SUV to time were 0.004, 0.003, and 0.0001 for malignant lesions, benign lesions, and background hepatic tissue, respectively. CONCLUSION An approximately 90-min time window from (18)F-FDG injection to PET imaging would significantly improve target-to-background ratio and, thus, quantitation and visual interpretation. This benefit outweighs the minimal loss in patient throughput.
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Abstract
Molecular imaging seeks to unravel critical molecular and cellular events in living subjects by providing complementary biological information to current structural clinical imaging modalities. In recent years, molecular imaging efforts have marched forward into the clinical cardiovascular arena, and are now actively illuminating new biology in a broad range of conditions, including atherosclerosis, myocardial infarction, thrombosis, vasculitis, aneurysm, cardiomyopathy, and valvular disease. Development of novel molecular imaging reporters is occurring for many clinical cardiovascular imaging modalities (positron emission tomography, single-photon emission computed tomography, magnetic resonance imaging), as well as in translational platforms such as intravascular fluorescence imaging. The ability to image, track, and quantify molecular biomarkers in organs not routinely amenable to biopsy (e.g., the heart and vasculature) open new clinical opportunities to tailor therapeutics based on a cardiovascular disease molecular profile. In addition, molecular imaging is playing an increasing role in atherosclerosis drug development in phase II clinical trials. Here, we present state-of-the-art clinical cardiovascular molecular imaging strategies, and explore promising translational approaches positioned for clinical testing in the near term.
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Affiliation(s)
- Eric A Osborn
- Cardiology Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Farouc A Jaffer
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Center for Molecular Imaging Research and Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
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Nitta Y, Tahara N, Tahara A, Honda A, Kodama N, Mizoguchi M, Kaida H, Ishibashi M, Hayabuchi N, Ikeda H, Yamagishi SI, Imaizumi T. Pioglitazone decreases coronary artery inflammation in impaired glucose tolerance and diabetes mellitus: evaluation by FDG-PET/CT imaging. JACC Cardiovasc Imaging 2014; 6:1172-82. [PMID: 24229770 DOI: 10.1016/j.jcmg.2013.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/14/2013] [Accepted: 09/13/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVES The aim of this study was to compare the effect of pioglitazone with glimepiride on coronary arterial inflammation with serial (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) combined with computed tomography (CT) angiography. BACKGROUND Recent studies have shown that FDG-PET combined with CT is a reliable tool to visualize and quantify vascular inflammation. Although pioglitazone significantly prevented the progression of coronary atherosclerosis and reduced the recurrence of myocardial infarction in patients with type 2 diabetes mellitus (DM), it remains unclear whether pioglitazone could attenuate coronary artery inflammation. METHODS Fifty atherosclerotic patients with impaired glucose tolerance or type 2 DM underwent determination of blood chemistries, anthropometric and inflammatory variables, and FDG-PET/CT angiography, and then were randomized to receive either pioglitazone or glimepiride for 16 weeks. Effects of the treatments on vascular inflammation of the left main trunk were evaluated by FDG-PET/CT angiography at baseline and end of the study. Vascular inflammation of the left main trunk was measured by blood-normalized standardized uptake value, known as a target-to-background ratio. RESULTS Three patients dropped out of the study during the assessment or treatment. Finally, 25 pioglitazone-treated patients and 22 glimepiride-treated patients (37 men; mean age: 68.1 ± 8.3 years; glycosylated hemoglobin: 6.72 ± 0.70%) completed the study. After 16-week treatments, fasting plasma glucose and glycosylated hemoglobin values were comparably reduced in both groups. Changes in target-to-background ratio values from baseline were significantly greater in the pioglitazone group than in the glimepiride group (-0.12 ± 0.06 vs. 0.09 ± 0.07, p = 0.032), as well as changes in high-sensitivity C-reactive protein (pioglitazone vs. glimepiride group: median: -0.24 [interquartile range (IQR): -1.58 to -0.04] mg/l vs. 0.08 [IQR: -0.07 to 0.79] mg/l, p = 0.031). CONCLUSIONS Our study indicated that pioglitazone attenuated left main trunk inflammation in patients with impaired glucose tolerance or DM in a glucose-lowering independent manner, suggesting that pioglitazone may protect against cardiac events in patients with impaired glucose tolerance or DM by suppressing coronary inflammation. (Anti-Inflammatory Effects of Pioglitazone; NCT00722631).
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Affiliation(s)
- Yoshikazu Nitta
- Department of Medicine, Division of Cardio-Vascular Medicine, Kurume University School of Medicine, Kurume, Japan
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Yang C, Hou VW, Girard EJ, Nelson LY, Seibel EJ. Target-to-background enhancement in multispectral endoscopy with background autofluorescence mitigation for quantitative molecular imaging. J Biomed Opt 2014; 19:76014. [PMID: 25027002 PMCID: PMC4098034 DOI: 10.1117/1.jbo.19.7.076014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 06/25/2014] [Indexed: 05/05/2023]
Abstract
Fluorescence molecular imaging with exogenous probes improves specificity for the detection of diseased tissues by targeting unambiguous molecular signatures. Additionally, increased diagnostic sensitivity is expected with the application of multiple molecular probes. We developed a real-time multispectral fluorescence-reflectance scanning fiber endoscope (SFE) for wide-field molecular imaging of fluorescent dye-labeled molecular probes at nanomolar detection levels. Concurrent multichannel imaging with the wide-field SFE also allows for real-time mitigation of the background autofluorescence (AF) signal, especially when fluorescein, a U.S. Food and Drug Administration approved dye, is used as the target fluorophore. Quantitative tissue AF was measured for the ex vivo porcine esophagus and murine brain tissues across the visible and nearinfrared spectra. AF signals were then transferred to the unit of targeted fluorophore concentration to evaluate the SFE detection sensitivity for sodium fluorescein and cyanine. Next, we demonstrated a real-time AF mitigation algorithm on a tissue phantom, which featured molecular probe targeted cells of high-grade dysplasia on a substrate containing AF species. The target-to-background ratio was enhanced by more than one order of magnitude when applying the real-time AF mitigation algorithm. Furthermore, a quantitative estimate of the fluorescein photodegradation (photobleaching) rate was evaluated and shown to be insignificant under the illumination conditions of SFE. In summary, the multichannel laser-based flexible SFE has demonstrated the capability to provide sufficient detection sensitivity, image contrast, and quantitative target intensity information for detecting small precancerous lesions in vivo.
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Affiliation(s)
- Chenying Yang
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, United States
| | - Vivian W. Hou
- University of Washington, Department of Biology, Seattle, Washington 98195, United States
| | - Emily J. Girard
- Fred Hutchinson Cancer Research Center, Clinical Research Division, Seattle, Washington 98109, United States
| | - Leonard Y. Nelson
- University of Washington, Department of Mechanical Engineering, Seattle, Washington 98195, United States
| | - Eric J. Seibel
- University of Washington, Department of Mechanical Engineering, Seattle, Washington 98195, United States
- Address all correspondence to: Eric J. Seibel,
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Subramanian S, Emami H, Vucic E, Singh P, Vijayakumar J, Fifer KM, Alon A, Shankar SS, Farkouh M, Rudd JHF, Fayad ZA, Van Dyke TE, Tawakol A. High-dose atorvastatin reduces periodontal inflammation: a novel pleiotropic effect of statins. J Am Coll Cardiol 2013; 62:2382-2391. [PMID: 24070911 DOI: 10.1016/j.jacc.2013.08.1627] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 07/25/2013] [Accepted: 08/12/2013] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The purpose of this study was to test whether high-dose statin treatment would result in a reduction in periodontal inflammation as assessed by (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT). BACKGROUND Periodontal disease (PD) is an independent risk factor for atherosclerosis. METHODS Eighty-three adults with risk factors or with established atherosclerosis and who were not taking high-dose statins were randomized to atorvastatin 80 mg vs. 10 mg in a multicenter, double-blind trial to evaluate the impact of atorvastatin on arterial inflammation. Subjects were evaluated using FDG-PET/CT at baseline and at 4 and 12 weeks. Arterial and periodontal tracer activity was assessed while blinded to treatment allocation, clinical characteristics, and temporal sequence. Periodontal bone loss (an index of PD severity) was evaluated using contrast-enhanced CT images while blinded to clinical and imaging data. RESULTS Seventy-one subjects completed the study, and 59 provided periodontal images for analysis. At baseline, areas of severe PD had higher target-to-background ratio (TBR) compared with areas without severe PD (mean TBR: 3.83 [95% confidence interval (CI): 3.36 to 4.30] vs. 3.18 [95% CI: 2.91 to 3.44], p = 0.004). After 12 weeks, there was a significant reduction in periodontal inflammation in patients randomized to atorvastatin 80 mg vs. 10 mg (ΔTBR 80 mg vs. 10 mg group: mean -0.43 [95% CI: -0.83 to -0.02], p = 0.04). Between-group differences were greater in patients with higher periodontal inflammation at baseline (mean -0.74 [95% CI: -1.29 to -0.19], p = 0.01) and in patients with severe bone loss at baseline (-0.61 [95% CI: -1.16 to -0.054], p = 0.03). Furthermore, the changes in periodontal inflammation correlated with changes in carotid inflammation (R = 0.61, p < 0.001). CONCLUSIONS High-dose atorvastatin reduces periodontal inflammation, suggesting a newly recognized effect of statins. Given the concomitant changes observed in periodontal and arterial inflammation, these data raise the possibility that a portion of that beneficial impact of statins on atherosclerosis relate to reductions in extra-arterial inflammation, for example, periodontitis. (Evaluate the Utility of 18FDG-PET as a Tool to Quantify Atherosclerotic Plaque; NCT00703261).
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Affiliation(s)
- Sharath Subramanian
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Hamed Emami
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Esad Vucic
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Parmanand Singh
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Jayanthi Vijayakumar
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Kenneth M Fifer
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Achilles Alon
- Merck Sharp & Dohme Corp., Whitehouse Station, New Jersey
| | | | - Michael Farkouh
- Peter Munk Cardiac Centre and the Heart and Stroke Richard Lewar Centre of Excellence, the University of Toronto, Toronto, Ontario, Canada
| | - James H F Rudd
- Division of Cardiovascular Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Zahi A Fayad
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | | | - Ahmed Tawakol
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
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Abstract
The number of molecular species suitable for multispectral fluorescence imaging is limited due to the overlap of the emission spectra of indicator fluorophores, e.g., dyes and nanoparticles. To remove fluorophore emission cross-talk in wide-field multispectral fluorescence molecular imaging, we evaluate three different solutions: (1) image stitching, (2) concurrent imaging with cross-talk ratio subtraction algorithm, and (3) frame-sequential imaging. A phantom with fluorophore emission cross-talk is fabricated, and a 1.2-mm ultrathin scanning fiber endoscope (SFE) is used to test and compare these approaches. Results show that fluorophore emission cross-talk could be successfully avoided or significantly reduced. Near term, the concurrent imaging method of wide-field multispectral fluorescence SFE is viable for early stage cancer detection and localization in vivo. Furthermore, a means to enhance exogenous fluorescence target-to-background ratio by the reduction of tissue autofluorescence background is demonstrated.
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Affiliation(s)
- Chenying Yang
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, USA.
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