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Cook EL, Su KH, Higgins GS, Johnsen R, Bouhnik JP, McGowan DR. Data-driven gating (DDG)-based motion match for improved CTAC registration. EJNMMI Phys 2024; 11:42. [PMID: 38691232 DOI: 10.1186/s40658-024-00644-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024] Open
Abstract
BACKGROUND Respiratory motion artefacts are a pitfall in thoracic PET/CT imaging. A source of these motion artefacts within PET images is the CT used for attenuation correction of the images. The arbitrary respiratory phase in which the helical CT ( CT helical ) is acquired often causes misregistration between PET and CT images, leading to inaccurate attenuation correction of the PET image. As a result, errors in tumour delineation or lesion uptake values can occur. To minimise the effect of motion in PET/CT imaging, a data-driven gating (DDG)-based motion match (MM) algorithm has been developed that estimates the phase of the CT helical , and subsequently warps this CT to a given phase of the respiratory cycle, allowing it to be phase-matched to the PET. A set of data was used which had four-dimensional CT (4DCT) acquired alongside PET/CT. The 4DCT allowed ground truth CT phases to be generated and compared to the algorithm-generated motion match CT (MMCT). Measurements of liver and lesion margin positions were taken across CT images to determine any differences and establish how well the algorithm performed concerning warping the CT helical to a given phase (end-of-expiration, EE). RESULTS Whilst there was a minor significance in the liver measurement between the 4DCT and MMCT ( p = 0.045 ), no significant differences were found between the 4DCT or MMCT for lesion measurements ( p = 1.0 ). In all instances, the CT helical was found to be significantly different from the 4DCT ( p < 0.001 ). Consequently, the 4DCT and MMCT can be considered equivalent with respect to warped CT generation, showing the DDG-based MM algorithm to be successful. CONCLUSION The MM algorithm successfully enables the phase-matching of a CT helical to the EE of a ground truth 4DCT. This would reduce the motion artefacts caused by PET/CT registration without requiring additional patient dose (required for a 4DCT).
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Affiliation(s)
- Ella L Cook
- Department of Oncology, University of Oxford, Oxford, UK
| | | | | | | | | | - Daniel R McGowan
- Department of Oncology, University of Oxford, Oxford, UK.
- Department of Medical Physics and Clinical Engineering, Oxford University Hospitals Foundation Trust, Oxford, UK.
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2
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Prediction of radioactive injection dosage for PET imaging. Soft comput 2021. [DOI: 10.1007/s00500-021-05577-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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3
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Lowe PT, Dall'Angelo S, Fleming IN, Piras M, Zanda M, O'Hagan D. Enzymatic radiosynthesis of a 18F-Glu-Ureido-Lys ligand for the prostate-specific membrane antigen (PSMA). Org Biomol Chem 2019; 17:1480-1486. [PMID: 30681115 DOI: 10.1039/c8ob03150a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Prostate cancer represents a major public health threat as it is one of the most common male cancers worldwide. The prostate-specific membrane antigen (PSMA) is highly over-expressed in prostatic cancer cells in a manner that correlates with both tumour stage and clinical outcome. As such, PSMA has been identified as an attractive target for both imaging and treatment of prostate cancer. In recent years the focus on urea-based peptidomimetic inhibitors of the PSMA (representing low molecular weight/high affinity binders) has intensified as they have found use in the clinical imaging of prostate tumours. Reported herein are the design, synthesis and evaluation of a new fluorinated PSMA targeting small-molecule, FDA-PEG-GUL, which possesses the Glu-NH-CO-NH-Lys pharmacophore conjugated to a 5'-fluorodeoxy-adenosine unit. Inhibition assays were performed with FDA-PEG-GUL which revealed that it inhibits the PSMA in the nanomolar range. Additionally, it has been purposely designed so that it can be produced using the fluorinase enzyme from its chlorinated precursor, allowing for the enzymatic synthesis of radiolabelled [18F]FDA-PEG-GUL via a nucleophilic reaction that takes place in experimentally advantageous conditions (in water at neutral pH and at ambient temperature). Specific binding of [18F]FDA-PEG-GUL to PSMA expressing cancer cells was demonstrated, validating it as a promising PSMA diagnostic tool. This work establishes a successful substrate scope expansion for the fluorinase and demonstrates its first application towards targeting the PSMA.
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Affiliation(s)
- Phillip T Lowe
- School of Chemistry and Biomedical Sciences Research Centre, University of St Andrews, North Haugh, St Andrews KY16 9ST, UK.
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Rahmim A, Lodge MA, Karakatsanis NA, Panin VY, Zhou Y, McMillan A, Cho S, Zaidi H, Casey ME, Wahl RL. Dynamic whole-body PET imaging: principles, potentials and applications. Eur J Nucl Med Mol Imaging 2018; 46:501-518. [PMID: 30269154 DOI: 10.1007/s00259-018-4153-6] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/28/2018] [Indexed: 02/07/2023]
Abstract
PURPOSE In this article, we discuss dynamic whole-body (DWB) positron emission tomography (PET) as an imaging tool with significant clinical potential, in relation to conventional standard uptake value (SUV) imaging. BACKGROUND DWB PET involves dynamic data acquisition over an extended axial range, capturing tracer kinetic information that is not available with conventional static acquisition protocols. The method can be performed within reasonable clinical imaging times, and enables generation of multiple types of PET images with complementary information in a single imaging session. Importantly, DWB PET can be used to produce multi-parametric images of (i) Patlak slope (influx rate) and (ii) intercept (referred to sometimes as "distribution volume"), while also providing (iii) a conventional 'SUV-equivalent' image for certain protocols. RESULTS We provide an overview of ongoing efforts (primarily focused on FDG PET) and discuss potential clinically relevant applications. CONCLUSION Overall, the framework of DWB imaging [applicable to both PET/CT(computed tomography) and PET/MRI (magnetic resonance imaging)] generates quantitative measures that may add significant value to conventional SUV image-derived measures, with limited pitfalls as we also discuss in this work.
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Affiliation(s)
- Arman Rahmim
- Department of Radiology and Radiological Science, Johns Hopkins University, JHOC Building Room 3245, 601 N. Caroline St, Baltimore, MD, 21287, USA. .,Departments of Radiology and Physics & Astronomy, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada.
| | - Martin A Lodge
- Department of Radiology and Radiological Science, Johns Hopkins University, JHOC Building Room 3245, 601 N. Caroline St, Baltimore, MD, 21287, USA
| | | | | | - Yun Zhou
- Department of Radiology and Radiological Science, Johns Hopkins University, JHOC Building Room 3245, 601 N. Caroline St, Baltimore, MD, 21287, USA
| | - Alan McMillan
- Department of Radiology, University of Wisconsin, Madison, WI, 53705, USA
| | - Steve Cho
- Department of Radiology, University of Wisconsin, Madison, WI, 53705, USA
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | | | - Richard L Wahl
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
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Lowe PT, Dall'Angelo S, Devine A, Zanda M, O'Hagan D. Enzymatic Fluorination of Biotin and Tetrazine Conjugates for Pretargeting Approaches to Positron Emission Tomography Imaging. Chembiochem 2018; 19:1969-1978. [PMID: 29966048 DOI: 10.1002/cbic.201800234] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Indexed: 12/15/2022]
Abstract
The use of radiolabelled antibodies and antibody-derived recombinant constructs has shown promise for both imaging and therapeutic use. In this context, the biotin-avidin/streptavidin pairing, along with the inverse-electron-demand Diels-Alder (iEDDA) reaction, have found application in pretargeting approaches for positron emission tomography (PET). This study reports the fluorinase-mediated transhalogenation [5'-chloro-5'-deoxyadenosine (ClDA) substrates to 5'-fluoro-5'-deoxyadenosine (FDA) products] of two antibody pretargeting tools, a FDA-PEG-tetrazine and a [18 F]FDA-PEG-biotin, and each is assessed either for its compatibility towards iEDDA ligation to trans-cyclooctene or for its affinity to avidin. A protocol to avoid radiolytically promoted oxidation of biotin during the synthesis of [18 F]FDA-PEG-biotin was developed. The study adds to the repertoire of conjugates for use in fluorinase-catalysed radiosynthesis for PET and shows that the fluorinase will accept a wide range of ClDA substrates tethered at C-2 of the adenine ring with a PEGylated cargo. The method is exceptional because the nucleophilic reaction with [18 F]fluoride takes place in water at neutral pH and at ambient temperature.
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Affiliation(s)
- Phillip T Lowe
- School of Chemistry and Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK
| | - Sergio Dall'Angelo
- John Mallard Scottish PET Centre, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Andrew Devine
- School of Chemistry and Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK
| | - Matteo Zanda
- John Mallard Scottish PET Centre, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - David O'Hagan
- School of Chemistry and Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK
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6
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O'Reilly DJ, Hodson J, Pike TW, Marudanayagam R, Sutcliffe RP, Muiesan P, Isaac J, A Lodge JP, Mirza DF, Roberts KJ. The rate of false-positive diagnosis of colorectal liver metastases in patients undergoing resection with the development of a novel, externally validated risk score. Surgery 2018; 164:238-243. [PMID: 29751969 DOI: 10.1016/j.surg.2018.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/05/2018] [Accepted: 02/20/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND Diagnostic error in patients undergoing resection of colorectal liver metastases (CRLM) is unusual but exposes patients to unnecessary risks associated with treatment. The primary aim of this study was to determine the rate of and risk factors for a false-positive diagnosis of colorectal liver metastases in patients undergoing hepatic resection. The secondary aim was to develop and validate a risk score to predict a false-positive diagnosis. METHODS Patients were identified from prospectively maintained databases. Patients who underwent a first liver resection for presumed colorectal liver metastases were divided into 2 groups: CRLMPOS (colorectal liver metastases present on histology or appearance of complete pathologic response to preoperative chemotherapy) and CRLMNEG (all others). Univariable analysis and multivariable binary logistic regression were used to identify risk factors for CRLMNEG. Risk scores were developed for CRLMNEG both with and without the use of preoperative carcinoembryonic antigen and were validated on an external cohort. RESULTS 3.1% of patients in both test and validation cohorts were CRLMNEG (39/1,252 and 59/1,900, respectively). CRLMNEG patients had fewer (P = .006) and smaller lesions (P < .001) with lower serum levels of carcinoembryonic antigen (P < .001), T (P = .031) and N (P < .001) and a lower Dukes' stage of the primary (P < .001). The risk score performed well (area under the receiver operating characteristic curve 0.869; standard error = 0.030; P < .001) with reasonable performance on validation (area under receiver operating characteristic curve 0.743; standard error = 0.058; P < .001]). CONCLUSION A false-positive diagnosis of colorectal liver metastases affected the same proportion of patients in 2 unrelated cohorts. This study identified risk factors for false-positive diagnosis with development of a novel risk score supported by external validation.
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Affiliation(s)
- David J O'Reilly
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK; Cardiff Liver Unit, Cardiff and Vale University Health Board, Cardiff, Wales.
| | - James Hodson
- Institute of Translational Medicine, Birmingham Health Partners, Birmigham, UK
| | - Thomas W Pike
- Hepatobiliary Surgery Unit, St James's University Hospital, Leeds, UK
| | - Ravi Marudanayagam
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Robert P Sutcliffe
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Paolo Muiesan
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - John Isaac
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - J Peter A Lodge
- Hepatobiliary Surgery Unit, St James's University Hospital, Leeds, UK
| | - Darius F Mirza
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Keith J Roberts
- Liver Unit, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
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7
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Pan T. Respiratory gating in PET/CT: A step in the right direction. J Nucl Cardiol 2018; 25:416-418. [PMID: 27580615 DOI: 10.1007/s12350-016-0647-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 08/09/2016] [Indexed: 10/21/2022]
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8
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Hutton BF, Erlandsson K, Thielemans K. Advances in clinical molecular imaging instrumentation. Clin Transl Imaging 2018. [DOI: 10.1007/s40336-018-0264-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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9
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Besemer AE, Titz B, Grudzinski JJ, Weichert JP, Kuo JS, Robins HI, Hall LT, Bednarz BP. Impact of PET and MRI threshold-based tumor volume segmentation on patient-specific targeted radionuclide therapy dosimetry using CLR1404. Phys Med Biol 2017; 62:6008-6025. [PMID: 28682793 DOI: 10.1088/1361-6560/aa716d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Variations in tumor volume segmentation methods in targeted radionuclide therapy (TRT) may lead to dosimetric uncertainties. This work investigates the impact of PET and MRI threshold-based tumor segmentation on TRT dosimetry in patients with primary and metastatic brain tumors. In this study, PET/CT images of five brain cancer patients were acquired at 6, 24, and 48 h post-injection of 124I-CLR1404. The tumor volume was segmented using two standardized uptake value (SUV) threshold levels, two tumor-to-background ratio (TBR) threshold levels, and a T1 Gadolinium-enhanced MRI threshold. The dice similarity coefficient (DSC), jaccard similarity coefficient (JSC), and overlap volume (OV) metrics were calculated to compare differences in the MRI and PET contours. The therapeutic 131I-CLR1404 voxel-level dose distribution was calculated from the 124I-CLR1404 activity distribution using RAPID, a Geant4 Monte Carlo internal dosimetry platform. The TBR, SUV, and MRI tumor volumes ranged from 2.3-63.9 cc, 0.1-34.7 cc, and 0.4-11.8 cc, respectively. The average ± standard deviation (range) was 0.19 ± 0.13 (0.01-0.51), 0.30 ± 0.17 (0.03-0.67), and 0.75 ± 0.29 (0.05-1.00) for the JSC, DSC, and OV, respectively. The DSC and JSC values were small and the OV values were large for both the MRI-SUV and MRI-TBR combinations because the regions of PET uptake were generally larger than the MRI enhancement. Notable differences in the tumor dose volume histograms were observed for each patient. The mean (standard deviation) 131I-CLR1404 tumor doses ranged from 0.28-1.75 Gy GBq-1 (0.07-0.37 Gy GBq-1). The ratio of maximum-to-minimum mean doses for each patient ranged from 1.4-2.0. The tumor volume and the interpretation of the tumor dose is highly sensitive to the imaging modality, PET enhancement metric, and threshold level used for tumor volume segmentation. The large variations in tumor doses clearly demonstrate the need for standard protocols for multimodality tumor segmentation in TRT dosimetry.
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Affiliation(s)
- Abigail E Besemer
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States of America. Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53705, United States of America
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10
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Swaid F, Downs D, Rosemurgy AS. A practical approach to liver metastasis from unknown primary cancer: What surgeons need to know. Cancer Genet 2016; 209:559-566. [DOI: 10.1016/j.cancergen.2016.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/04/2016] [Indexed: 12/18/2022]
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11
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Chakravarty R, Chakraborty S, Dash A. 64Cu2+ Ions as PET Probe: An Emerging Paradigm in Molecular Imaging of Cancer. Mol Pharm 2016; 13:3601-3612. [DOI: 10.1021/acs.molpharmaceut.6b00582] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Rubel Chakravarty
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Sudipta Chakraborty
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Ashutosh Dash
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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12
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Shen G, Hu S, Liu B, Kuang A. Diagnostic Performance of Whole-Body PET/MRI for Detecting Malignancies in Cancer Patients: A Meta-Analysis. PLoS One 2016; 11:e0154497. [PMID: 27124545 PMCID: PMC4849712 DOI: 10.1371/journal.pone.0154497] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/14/2016] [Indexed: 02/05/2023] Open
Abstract
Background As an evolving imaging modality, PET/MRI is preliminarily applied in clinical practice. The aim of this study was to assess the diagnostic performance of PET/MRI for tumor staging in patients with various types of cancer. Methods Relevant articles about PET/MRI for cancer staging were systematically searched in PubMed, EMBASE, EBSCO and the Cochrane Library. Two researchers independently selected studies, extracted data and assessed the methodological quality using the QUADAS tool. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated per patient and per lesion. The summary receiver-operating characteristic (SROC) curves were also constructed, and the area under the curve (AUC) and Q* estimates were obtained. Results A total of 38 studies that involved 753 patients and 4234 lesions met the inclusion criteria. On a per-patient level, the pooled sensitivity and specificity with 95% confidence intervals (CIs) were 0.93 (0.90–0.95) and 0.92 (0.89–0.95), respectively. On a per-lesion level, the corresponding estimates were 0.90 (0.88–0.92) and 0.95 (0.94–0.96), respectively. The pooled PLR, NLR and DOR estimates were 6.67 (4.83–9.19), 0.12 (0.07–0.21) and 75.08 (42.10–133.91) per patient and 10.91 (6.79–17.54), 0.13 (0.08–0.19) and 102.53 (59.74–175.97) per lesion, respectively. Conclusion According to our results, PET/MRI has excellent diagnostic potential for the overall detection of malignancies in cancer patients. Large, multicenter and prospective studies with standard scanning protocols are required to evaluate the diagnostic value of PET/MRI for individual cancer types.
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Affiliation(s)
- Guohua Shen
- Department of Nuclear Medicine, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Shuang Hu
- Department of Nuclear Medicine, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Bin Liu
- Department of Nuclear Medicine, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu, Sichuan, 610041, People’s Republic of China
| | - Anren Kuang
- Department of Nuclear Medicine, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu, Sichuan, 610041, People’s Republic of China
- * E-mail:
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Chun SY. The Use of Anatomical Information for Molecular Image Reconstruction Algorithms: Attenuation/Scatter Correction, Motion Compensation, and Noise Reduction. Nucl Med Mol Imaging 2016; 50:13-23. [PMID: 26941855 DOI: 10.1007/s13139-016-0399-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/11/2016] [Accepted: 01/13/2016] [Indexed: 01/05/2023] Open
Abstract
PET and SPECT are important tools for providing valuable molecular information about patients to clinicians. Advances in nuclear medicine hardware technologies and statistical image reconstruction algorithms enabled significantly improved image quality. Sequentially or simultaneously acquired anatomical images such as CT and MRI from hybrid scanners are also important ingredients for improving the image quality of PET or SPECT further. High-quality anatomical information has been used and investigated for attenuation and scatter corrections, motion compensation, and noise reduction via post-reconstruction filtering and regularization in inverse problems. In this article, we will review works using anatomical information for molecular image reconstruction algorithms for better image quality by describing mathematical models, discussing sources of anatomical information for different cases, and showing some examples.
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Affiliation(s)
- Se Young Chun
- School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
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Apostolova I, Wedel F, Brenner W. Imaging of Tumor Metabolism Using Positron Emission Tomography (PET). Recent Results Cancer Res 2016; 207:177-205. [PMID: 27557539 DOI: 10.1007/978-3-319-42118-6_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Molecular imaging employing PET/CT enables in vivo visualization, characterization, and measurement of biologic processes in tumors at a molecular and cellular level. Using specific metabolic tracers, information about the integrated function of multiple transporters and enzymes involved in tumor metabolic pathways can be depicted, and the tracers can be directly applied as biomarkers of tumor biology. In this review, we discuss the role of F-18-fluorodeoxyglucose (FDG) as an in vivo glycolytic marker which reflects alterations of glucose metabolism in cancer cells. This functional molecular imaging technique offers a complementary approach to anatomic imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) and has found widespread application as a diagnostic modality in oncology to monitor tumor biology, optimize the therapeutic management, and guide patient care. Moreover, emerging methods for PET imaging of further biologic processes relevant to cancer are reviewed, with a focus on tumor hypoxia and aberrant tumor perfusion. Hypoxic tumors are associated with poor disease control and increased resistance to cytotoxic and radiation treatment. In vivo imaging of hypoxia, perfusion, and mismatch of metabolism and perfusion has the potential to identify specific features of tumor microenvironment associated with poor treatment outcome and, thus, contribute to personalized treatment approaches.
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Affiliation(s)
- Ivayla Apostolova
- Department of Radiology and Nuclear Medicine, Medical School, Otto-von-Guericke University, Magdeburg A.ö.R., Magdeburg, Germany
| | - Florian Wedel
- Department of Nuclear Medicine, University Medicine Charité, Berlin, Germany
| | - Winfried Brenner
- Department of Nuclear Medicine, University Medicine Charité, Berlin, Germany.
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15
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The edge artifact in the point-spread function-based PET reconstruction at different sphere-to-background ratios of radioactivity. Ann Nucl Med 2015; 30:97-103. [PMID: 26531181 DOI: 10.1007/s12149-015-1036-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Accepted: 10/28/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The aim of this study was to quantitatively evaluate the edge artifacts in PET images reconstructed using the point-spread function (PSF) algorithm at different sphere-to-background ratios of radioactivity (SBRs). METHODS We used a NEMA IEC body phantom consisting of six spheres with 37, 28, 22, 17, 13 and 10 mm in inner diameter. The background was filled with (18)F solution with a radioactivity concentration of 2.65 kBq/mL. We prepared three sets of phantoms with SBRs of 16, 8, 4 and 2. The PET data were acquired for 20 min using a Biograph mCT scanner. The images were reconstructed with the baseline ordered subsets expectation maximization (OSEM) algorithm, and with the OSEM + PSF correction model (PSF). For the image reconstruction, the number of iterations ranged from one to 10. The phantom PET image analyses were performed by a visual assessment of the PET images and profiles, a contrast recovery coefficient (CRC), which is the ratio of SBR in the images to the true SBR, and the percent change in the maximum count between the OSEM and PSF images (Δ % counts). RESULTS In the PSF images, the spheres with a diameter of 17 mm or larger were surrounded by a dense edge in comparison with the OSEM images. In the spheres with a diameter of 22 mm or smaller, an overshoot appeared in the center of the spheres as a sharp peak in the PSF images in low SBR. These edge artifacts were clearly observed in relation to the increase of the SBR. The overestimation of the CRC was observed in 13 mm spheres in the PSF images. In the spheres with a diameter of 17 mm or smaller, the Δ % counts increased with an increasing SBR. The Δ % counts increased to 91 % in the 10-mm sphere at the SBR of 16. CONCLUSIONS The edge artifacts in the PET images reconstructed using the PSF algorithm increased with an increasing SBR. In the small spheres, the edge artifact was observed as a sharp peak at the center of spheres and could result in overestimation.
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Thompson S, Onega M, Ashworth S, Fleming IN, Passchier J, O'Hagan D. A two-step fluorinase enzyme mediated 18F labelling of an RGD peptide for positron emission tomography. Chem Commun (Camb) 2015. [DOI: 10.1039/c5cc05013h] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Fluorine-18 radiolabelling of a peptide is conducted in water (pH 7.8 and 37 °C) using the fluorinase enzyme and a ‘click’ reaction.
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Affiliation(s)
- S. Thompson
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - M. Onega
- Imanova
- Burlington Danes Building
- Imperial College London
- Hammersmith Hospital
- London
| | - S. Ashworth
- Imanova
- Burlington Danes Building
- Imperial College London
- Hammersmith Hospital
- London
| | - I. N. Fleming
- Aberdeen Biomedical Imaging Centre
- School of Medicine and Dentistry
- University of Aberdeen
- Aberdeen
- UK
| | - J. Passchier
- Imanova
- Burlington Danes Building
- Imperial College London
- Hammersmith Hospital
- London
| | - D. O'Hagan
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
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Imaging Approach to Hepatocellular Carcinoma, Cholangiocarcinoma, and Metastatic Colorectal Cancer. Surg Oncol Clin N Am 2015; 24:19-40. [DOI: 10.1016/j.soc.2014.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Integrated whole-body PET/MRI with 18F-FDG, 18F-FDOPA, and 18F-FDA in paragangliomas in comparison with PET/CT: NIH first clinical experience with a single-injection, dual-modality imaging protocol. Clin Nucl Med 2014; 39:243-50. [PMID: 24152658 DOI: 10.1097/rlu.0000000000000289] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Paragangliomas (PGLs) are tumors that can metastasize and recur; therefore, lifelong imaging follow-up is required. Hybrid PET/CT is an essential tool to image PGLs. Novel hybrid PET/MRI scanners are currently being studied in clinical oncology. We studied the feasibility of simultaneous whole-body PET/MRI to evaluate patients with PGLs. METHODS Fifty-three PGLs or PGL-related lesions from 8 patients were evaluated. All patients underwent a single-injection, dual-modality imaging protocol consisting of a PET/CT and a subsequent PET/MRI scan. Four patients were evaluated with F-FDG, 2 with F-fluorodihydroxyphenylalanine, and 2 with F-fluorodopamine. PET/MRI data were acquired using a hybrid whole-body 3-tesla integrated PET/MRI scanner. PET and MRI data (Dixon sequence for attenuation correction and T2-weighted sequences for anatomic allocation) were acquired simultaneously. Imaging workflow and imaging times were documented. PET/MRI and PET/CT data were visually assessed (blindly) in regards to image quality, lesion detection, and anatomic allocation and delineation of the PET findings. RESULTS With hybrid PET/MRI, we obtained high-quality images in an acceptable acquisition time (median, 31 minutes; range, 25-40 minutes) with good patient compliance. A total of 53 lesions, located in the head and neck area (6 lesions), mediastinum (2 lesions), abdomen and pelvis (13 lesions), lungs (2 lesions), liver (4 lesions), and bones (26 lesions), were evaluated. Fifty-one lesions were detected with PET/MRI and confirmed by PET/CT. Two bone lesions (L4 body, 8 mm, and sacrum, 6 mm) were not detectable on an F-FDA scan PET/MRI, likely because F-FDA was washed out between PET/CT and PET/MRI acquisitions. Coregistered MRI tended to be superior to coregistered CT for head and neck, abdomen, pelvis, and liver lesions for anatomic allocation and delineation. CONCLUSIONS Clinical PGL evaluation with hybrid PET/MRI is feasible with high-quality image and can be obtained in a reasonable time. It could be particularly beneficial for the pediatric population and for precise lesion definition in the head and neck, abdomen, pelvis, and liver.
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Intven M, Reerink O, Philippens MEP. Dynamic contrast enhanced MR imaging for rectal cancer response assessment after neo-adjuvant chemoradiation. J Magn Reson Imaging 2014; 41:1646-53. [PMID: 25124320 DOI: 10.1002/jmri.24718] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 07/17/2014] [Accepted: 07/18/2014] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Patient selection for organ sparing treatment after good response to neo-adjuvant chemoradiation (CRT) for locally advanced rectal cancer is challenging as no optimal restaging modality is available after CRT. In this study, we assessed the value of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for rectal cancer pathological response prediction. METHODS In 51 patients with locally advanced rectal cancer, the tumor volume and volume transfer constant (Ktrans) were obtained at 3 Tesla before CRT and surgery. The predictive potential for pathological complete response (pCR) and good response (GR) was assessed. GR was defined as pCR and near-pCR based on the tumor regression grade. RESULTS The GR group consisted of 10 patients (19.6%) with six pCR (11.8%). Both the post-CRT tumor volume and post-CRT Ktrans values and the relative change in volume (ΔVolume) and Ktrans (ΔKtrans) were predictive for pathological response. ΔKtrans showed the best predictive potential with a positive predictive value (PPV) of 100% for GR using a cutoff value of 32% reduction in Ktrans. For pCR the best PPV was 80% with a multiparameter model containing ΔVolume and ΔKtrans. CONCLUSION DCE-MRI has predictive potential for pathological response after CRT in rectal cancer with the relative ΔKtrans being the most predictive parameter.
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Affiliation(s)
- Martijn Intven
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Onne Reerink
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
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Izuishi K, Yamamoto Y, Mori H, Kameyama R, Fujihara S, Masaki T, Suzuki Y. Molecular mechanisms of [18F]fluorodeoxyglucose accumulation in liver cancer. Oncol Rep 2013; 31:701-6. [PMID: 24297035 DOI: 10.3892/or.2013.2886] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 10/25/2013] [Indexed: 11/06/2022] Open
Abstract
To elucidate the molecular mechanisms underlying the insufficient sensitivity in the detection of hepatocellular carcinoma (HCC) by [18F] 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), the characteristics of glucose metabolism-related protein expression in HCC were examined in liver metastasis from colorectal cancer (Meta). Thirty-four patients (14 Meta and 20 HCC) who underwent FDG-PET and hepatectomy were studied. The relationships between the maximum standardized uptake value (SUV) in tumors and the mRNA expression of glucose metabolism-related proteins [hexokinase (HK), glucose transporter 1 (GLUT1), and glucose-6-phosphatase (G6Pase)] and proliferating cell nuclear antigen (PCNA) were examined in snap-frozen specimens with quantitative PCR. Tumor detection rates were lower in HCC (15/20) compared to Meta (13/14) patients. HK and GLUT1 expression was lower and G6Pase expression was higher in HCC compared to Meta. In particular, GLUT1 overexpression was 92-fold in Meta and 11-fold in HCC compared to the surrounding liver. The SUV correlated with GLUT1 and PCNA expression in HCC, but not Meta patients. Of note, four cases of poorly differentiated (P/D) HCC compared to moderately differentiated (M/D) HCC produced completely different results for FDG uptake (SUV, 14.4 vs. 4.0) and mRNA expression (G6Pase expression, 0.007 vs. 1.5). Variations in the expression of glucose metabolism-related enzymes between HCC and Meta patients are attributed to origin or degree of differentiation. Low FDG uptake in M/D HCC reflected low GLUT1 and high G6Pase expression, while high FDG accumulation in P/D HCC could reflect increased GLUT1 and decreased G6Pase expression. These results may explain why M/D HCC is not detected as sensitively by FDG-PET.
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Affiliation(s)
- Kunihiko Izuishi
- Department of Gastroenterological Surgery, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
| | - Yuka Yamamoto
- Department of Radiology, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
| | - Hirohito Mori
- Department of Internal Medicine of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
| | - Riko Kameyama
- Department of Radiology, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
| | - Shintaro Fujihara
- Department of Internal Medicine of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
| | - Tsutomu Masaki
- Department of Internal Medicine of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
| | - Yasuyuki Suzuki
- Department of Gastroenterological Surgery, Faculty of Medicine, Kagawa University, Miki, Kita, Kagawa 761-0793, Japan
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Molecular imaging in the development of a novel treatment paradigm for glioblastoma (GBM): an integrated multidisciplinary commentary. Drug Discov Today 2013; 18:1052-66. [DOI: 10.1016/j.drudis.2013.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 06/03/2013] [Accepted: 06/11/2013] [Indexed: 12/29/2022]
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Fowler KJ, McConathy J, Narra VR. Whole-body simultaneous positron emission tomography (PET)-MR: Optimization and adaptation of MRI sequences. J Magn Reson Imaging 2013; 39:259-68. [DOI: 10.1002/jmri.24308] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 06/18/2013] [Indexed: 11/12/2022] Open
Affiliation(s)
- Kathryn J. Fowler
- Department of Radiology; Washington University; St. Louis Missouri USA
| | - Jon McConathy
- Department of Radiology; Washington University; St. Louis Missouri USA
| | - Vamsi R. Narra
- Department of Radiology; Washington University; St. Louis Missouri USA
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Abstract
OBJECTIVE The purposes of this article are to summarize the basic concept and the strategies of reporter imaging; introduce reporter genes frequently used in optical imaging, nuclear medicine, and MRI for in vivo application; and show typical examples of reporter gene imaging. CONCLUSION In molecular biology, many reporter genes have been developed for monitoring cellular processes. Development of controlled gene delivery systems promotes construction of various types of reporter genes for monitoring the level of a gene expression, promoter activity, and protein-protein interaction. When an imaging reporter gene is placed under the control of a promoter, the amount of reporter protein can be dynamically visualized in vivo. Instrumental advances in molecular imaging have increased the sensitivity and resolution of in vivo reporter imaging. Though several types of reporters and multimodal imaging instruments are currently available, more efficient multimodal reporter gene systems and detectors compatible with several imaging modalities are needed.
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Variance of SUVs for FDG-PET/CT is greater in clinical practice than under ideal study settings. Clin Nucl Med 2013; 38:175-82. [PMID: 23354032 DOI: 10.1097/rlu.0b013e318279ffdf] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE Measurement variance affects the clinical effectiveness of PET-based measurement as a semiquantitative imaging biomarker for cancer response in individual patients and for planning clinical trials. In this study, we measured test-retest reproducibility of SUV measurements under clinical practice conditions and recorded recognized deviations from protocol compliance. METHODS Instrument performance calibration, display, and analyses conformed to manufacture recommendations. Baseline clinical (18)F-FDG PET/CT examinations were performed and then repeated at 1 to 7 days. Intended scan initiation uptake period was to repeat the examinations at the same time for each study after injection of 12 mCi FDG tracer. Avidity of uptake was measured in 62 tumors in 21 patients as SUV for maximum voxel (SUV(max)) and for a mean of sampled tumor voxels (SUV(mean)). RESULTS The range of SUV(max) and SUV(mean) was 1.07 to 21.47 and 0.91 to 14.69, respectively. Intraclass correlation coefficient between log of SUV(max) and log of SUV(mean) was 0.93 (95% confidence interval [CI], 0.88-0.95) and 0.92 (95% CI, 0.87-0.95), respectively.Correlation analysis failed to show an effect on uptake period variation on SUV measurements between the 2 examinations, suggesting additional sources of noise.The threshold criteria for relative difference from baseline for the 95% CI were ± 49% or ± 44% for SUV(max) or SUV(mean), respectively. CONCLUSIONS Variance of SUV for FDG-PET/CT in current clinical practice in a single institution was greater than expected when compared with benchmarks reported under stringent efficacy study settings. Under comparable clinical practice conditions, interpretation of changes in tumor avidity in individuals and assumptions in planning clinical trials may be affected.
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Overview of positron emission tomography, hybrid positron emission tomography instrumentation, and positron emission tomography quantification. J Thorac Imaging 2013; 28:4-10. [PMID: 23249967 DOI: 10.1097/rti.0b013e31827882d9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Positron emission tomography (PET) is a powerful quantitative molecular imaging technique that is complementary to structural imaging techniques for purposes of disease detection and characterization. This review article provides a brief overview of PET, hybrid PET instrumentation, and PET quantification.
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Randall EK, Kraft SL, Yoshikawa H, LaRue SM. Evaluation of 18F-FDG PET/CT as a diagnostic imaging and staging tool for feline oral squamous cell carcinoma. Vet Comp Oncol 2013; 14:28-38. [DOI: 10.1111/vco.12047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 05/03/2013] [Accepted: 05/14/2013] [Indexed: 11/29/2022]
Affiliation(s)
- E. K. Randall
- Department of Environmental and Radiological Health Sciences; Colorado State University; Fort Collins CO USA
| | - S. L. Kraft
- Department of Environmental and Radiological Health Sciences; Colorado State University; Fort Collins CO USA
| | - H. Yoshikawa
- Department of Environmental and Radiological Health Sciences; Colorado State University; Fort Collins CO USA
| | - S. M. LaRue
- Department of Environmental and Radiological Health Sciences; Colorado State University; Fort Collins CO USA
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Rahmim A, Qi J, Sossi V. Resolution modeling in PET imaging: theory, practice, benefits, and pitfalls. Med Phys 2013; 40:064301. [PMID: 23718620 PMCID: PMC3663852 DOI: 10.1118/1.4800806] [Citation(s) in RCA: 217] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 02/22/2013] [Accepted: 03/26/2013] [Indexed: 01/11/2023] Open
Abstract
In this paper, the authors review the field of resolution modeling in positron emission tomography (PET) image reconstruction, also referred to as point-spread-function modeling. The review includes theoretical analysis of the resolution modeling framework as well as an overview of various approaches in the literature. It also discusses potential advantages gained via this approach, as discussed with reference to various metrics and tasks, including lesion detection observer studies. Furthermore, attention is paid to issues arising from this approach including the pervasive problem of edge artifacts, as well as explanation and potential remedies for this phenomenon. Furthermore, the authors emphasize limitations encountered in the context of quantitative PET imaging, wherein increased intervoxel correlations due to resolution modeling can lead to significant loss of precision (reproducibility) for small regions of interest, which can be a considerable pitfall depending on the task of interest.
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Affiliation(s)
- Arman Rahmim
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21287, USA.
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28
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Molecular imaging of experimental abdominal aortic aneurysms. ScientificWorldJournal 2013; 2013:973150. [PMID: 23737735 PMCID: PMC3655677 DOI: 10.1155/2013/973150] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 03/19/2013] [Indexed: 11/18/2022] Open
Abstract
Current laboratory research in the field of abdominal aortic aneurysm (AAA) disease often utilizes small animal experimental models induced by genetic manipulation or chemical application. This has led to the use and development of multiple high-resolution molecular imaging modalities capable of tracking disease progression, quantifying the role of inflammation, and evaluating the effects of potential therapeutics. In vivo imaging reduces the number of research animals used, provides molecular and cellular information, and allows for longitudinal studies, a necessity when tracking vessel expansion in a single animal. This review outlines developments of both established and emerging molecular imaging techniques used to study AAA disease. Beyond the typical modalities used for anatomical imaging, which include ultrasound (US) and computed tomography (CT), previous molecular imaging efforts have used magnetic resonance (MR), near-infrared fluorescence (NIRF), bioluminescence, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). Mouse and rat AAA models will hopefully provide insight into potential disease mechanisms, and the development of advanced molecular imaging techniques, if clinically useful, may have translational potential. These efforts could help improve the management of aneurysms and better evaluate the therapeutic potential of new treatments for human AAA disease.
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Jin S, Li D, Wang H, Yin Y. Registration of PET and CT images based on multiresolution gradient of mutual information demons algorithm for positioning esophageal cancer patients. J Appl Clin Med Phys 2013; 14:3931. [PMID: 23318381 PMCID: PMC5713664 DOI: 10.1120/jacmp.v14i1.3931] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 08/22/2012] [Accepted: 08/22/2012] [Indexed: 11/23/2022] Open
Abstract
Accurate registration of 18F−FDG PET (positron emission tomography) and CT (computed tomography) images has important clinical significance in radiation oncology. PET and CT images are acquired from 18F−FDG PET/CT scanner, but the two acquisition processes are separate and take a long time. As a result, there are position errors in global and deformable errors in local caused by respiratory movement or organ peristalsis. The purpose of this work was to implement and validate a deformable CT to PET image registration method in esophageal cancer to eventually facilitate accurate positioning the tumor target on CT, and improve the accuracy of radiation therapy. Global registration was firstly utilized to preprocess position errors between PET and CT images, achieving the purpose of aligning these two images on the whole. Demons algorithm, based on optical flow field, has the features of fast process speed and high accuracy, and the gradient of mutual information‐based demons (GMI demons) algorithm adds an additional external force based on the gradient of mutual information (GMI) between two images, which is suitable for multimodality images registration. In this paper, GMI demons algorithm was used to achieve local deformable registration of PET and CT images, which can effectively reduce errors between internal organs. In addition, to speed up the registration process, maintain its robustness, and avoid the local extremum, multiresolution image pyramid structure was used before deformable registration. By quantitatively and qualitatively analyzing cases with esophageal cancer, the registration scheme proposed in this paper can improve registration accuracy and speed, which is helpful for precisely positioning tumor target and developing the radiation treatment planning in clinical radiation therapy application. PACS numbers: 87.57.nj, 87.57.Q‐, 87.57.uk
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Affiliation(s)
- Shuo Jin
- School of Information Science and Engineering, Shandong University, Shandong, China
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Pan T, Zaidi H. Attenuation Correction Strategies for Positron Emission Tomography/Computed Tomography and 4-Dimensional Positron Emission Tomography/Computed Tomography. PET Clin 2012; 8:37-50. [PMID: 27157814 DOI: 10.1016/j.cpet.2012.09.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4-dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list-mode data acquisition in 4-dimensional PET, and introduces 4-dimensional CT, popular in thoracic treatment planning, to 4-dimensional PET/CT.
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Affiliation(s)
- Tinsu Pan
- Department of Imaging Physics, MD Anderson Cancer Center, The University of Texas, Unit 1352, 1515 Holcome Boulevard, Houston, TX 77030, USA.
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva, Switzerland; Geneva Neuroscience Center, Geneva University, CH-1211 Geneva, Switzerland; Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, Netherlands
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Sharma B, Martin A, Stanway S, Johnston SRD, Constantinidou A. Imaging in oncology--over a century of advances. Nat Rev Clin Oncol 2012; 9:728-37. [PMID: 23149892 DOI: 10.1038/nrclinonc.2012.195] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Over the past 120 years, the discipline of oncology has evolved so that a multitude of anatomical and increasingly complex functional imaging techniques are now applicable in both clinical and research platforms. This Timeline article revisits the achievements of the pioneer techniques in cancer imaging, discusses how these techniques have changed over time, provides some examples of clinical importance, and ventures to explain how imaging will remodel the future of modern oncology.
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Affiliation(s)
- Bhuey Sharma
- Department of Imaging, Royal Marsden Hospital, Fulham Road, London, UK
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Diagnostic value of combined ¹⁸F-FDG PET/MRI for staging and restaging in paediatric oncology. Eur J Nucl Med Mol Imaging 2012; 39:1745-55. [PMID: 22926713 DOI: 10.1007/s00259-012-2228-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 08/09/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE The present study compares the diagnostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and MRI to combined/registered (18)F-FDG PET/MRI for staging and restaging in paediatric oncology. METHODS Over 8 years and 2 months, 270 (18)F-FDG PET and 270 MRI examinations (mean interval 5 days) were performed in 132 patients with proven (n = 117) or suspected (n = 15) malignant disease: solid tumours (n = 64), systemic malignancy (n = 53) and benign disease (n = 15). A total of 259 suspected tumour lesions were analysed retrospectively during primary diagnosis and 554 lesions during follow-up. Image analysis was performed separately on each modality, followed by analysis of combined and registered (18)F-FDG PET/MRI imaging. RESULTS A total of 813 lesions were evaluated and confirmed by histopathology (n = 158) and/or imaging follow-up (n = 655) after 6 months. In the separate analysis of (18)F-FDG PET and MRI, sensitivity was 86 %/94 % and specificity 85 %/38 %. Combined/registered (18)F-FDG PET/MRI led to a sensitivity of 97 %/97 % and specificity of 81 %/82 %. False-positive results ((18)F-FDG PET n = 69, MRI n = 281, combined (18)F-FDG PET/MRI n = 85, registered (18)F-FDG PET/MRI n = 80) were due to physiological uptake or post-therapeutic changes. False-negative results ((18)F-FDG PET n = 50, MRI n = 20, combined (18)F-FDG PET/MRI n = 11, registered (18)F-FDG PET/MRI n = 11) were based on low uptake or minimal morphological changes. Examination-based evaluation during follow-up showed a sensitivity/specificity of 91 %/81 % for (18)F-FDG PET, 93 %/30 % for MRI and 96 %/72 % for combined (18)F-FDG PET/MRI. CONCLUSION For the detection of single tumour lesions, registered (18)F-FDG PET/MRI proved to be the methodology of choice for adequate tumour staging. In the examination-based evaluation, MRI alone performed better than (18)F-FDG PET and combined/registered imaging during primary diagnosis. At follow-up, however, the examination-based evaluation demonstrated a superiority of (18)F-FDG PET alone.
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Chun SY, Reese TG, Ouyang J, Guerin B, Catana C, Zhu X, Alpert NM, El Fakhri G. MRI-based nonrigid motion correction in simultaneous PET/MRI. J Nucl Med 2012; 53:1284-91. [PMID: 22743250 DOI: 10.2967/jnumed.111.092353] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Respiratory and cardiac motion is the most serious limitation to whole-body PET, resulting in spatial resolution close to 1 cm. Furthermore, motion-induced inconsistencies in the attenuation measurements often lead to significant artifacts in the reconstructed images. Gating can remove motion artifacts at the cost of increased noise. This paper presents an approach to respiratory motion correction using simultaneous PET/MRI to demonstrate initial results in phantoms, rabbits, and nonhuman primates and discusses the prospects for clinical application. METHODS Studies with a deformable phantom, a free-breathing primate, and rabbits implanted with radioactive beads were performed with simultaneous PET/MRI. Motion fields were estimated from concurrently acquired tagged MR images using 2 B-spline nonrigid image registration methods and incorporated into a PET list-mode ordered-subsets expectation maximization algorithm. Using the measured motion fields to transform both the emission data and the attenuation data, we could use all the coincidence data to reconstruct any phase of the respiratory cycle. We compared the resulting SNR and the channelized Hotelling observer (CHO) detection signal-to-noise ratio (SNR) in the motion-corrected reconstruction with the results obtained from standard gating and uncorrected studies. RESULTS Motion correction virtually eliminated motion blur without reducing SNR, yielding images with SNR comparable to those obtained by gating with 5-8 times longer acquisitions in all studies. The CHO study in dynamic phantoms demonstrated a significant improvement (166%-276%) in lesion detection SNR with MRI-based motion correction as compared with gating (P < 0.001). This improvement was 43%-92% for large motion compared with lesion detection without motion correction (P < 0.001). CHO SNR in the rabbit studies confirmed these results. CONCLUSION Tagged MRI motion correction in simultaneous PET/MRI significantly improves lesion detection compared with respiratory gating and no motion correction while reducing radiation dose. In vivo primate and rabbit studies confirmed the improvement in PET image quality and provide the rationale for evaluation in simultaneous whole-body PET/MRI clinical studies.
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Affiliation(s)
- Se Young Chun
- Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, MA 02114, USA
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Patel P, Finger PT. Whole-body 18F FDG positron emission tomography/computed tomography evaluation of patients with uveal metastasis. Am J Ophthalmol 2012; 153:661-8. [PMID: 22264690 DOI: 10.1016/j.ajo.2011.09.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/18/2011] [Accepted: 09/19/2011] [Indexed: 10/14/2022]
Abstract
PURPOSE To investigate the value of whole-body positron emission tomography/computed tomography (PET/CT) as a screening tool for patients with uveal metastasis. DESIGN Retrospective observational case series. METHODS setting: Clinical practice. study population: Eighteen patients with uveal metastatic tumors were evaluated. Patients had no history of malignancy or a past medical history of malignancy without known active metastasis or known systemic cancer. intervention: Whole-body PET/CT was used as a screening tool to evaluate the intraocular tumor, to evaluate for multi-organ metastatic disease, and for cancer staging. main outcome measures: Detection and PET/CT uptake of primary tumors and metastatic disease. RESULTS PET/CT imaging uncovered previously occult primary nonocular cancers (11/18, 61%), revealed progression of known primary systemic cancer (7/18, 39%), and confirmed multi-organ metastases in all cases (18/18, 100%). PET/CT findings were used to direct nonocular, confirmatory biopsy in 67% of cases (12/18). No uveal biopsies were required. PET/CT revealed lymph nodes and bone as the most common metastatic sites. The intraocular tumor was detectable in 28% of cases. Small, non-avid tumors and those within the hypermetabolic, PET-avid brain were falsely negative. CONCLUSION This study suggests that whole-body PET/CT can be useful for clinical evaluation of patients with uveal metastases. It allowed for screening of the entire body and directed extraocular biopsy. Commonly used for tumor staging, PET/CT aided in the detection of the primary cancer in patients with metastatic uveal tumors.
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Dynamic PET-CT studies for characterizing nasopharyngeal carcinoma metabolism: comparison of analytical methods. Nucl Med Commun 2012; 33:191-7. [PMID: 22107997 DOI: 10.1097/mnm.0b013e32834dfa0c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To investigate the optimal PET protocol and analytical method to characterize the glucose metabolism in nasopharyngeal carcinoma (NPC). METHODS Newly diagnosed NPC patients were recruited and a dynamic PET-CT scan was performed. The optimized threshold to derive the arterial input function (AIF) was studied. Two-tissue compartmental kinetic modeling using three, four, and five parameters, Patlak graphical analysis, and time sensitivity (S-factor) analysis were performed. The best compartmental model was determined in terms of goodness of fit, and correlated with Ki from Patlak graphical analysis and the S-factor. The methods with R>0.9 and P<0.05 were considered acceptable. The protocols using two static scans with its retention index (RI=(SUV(2)/SUV(1)-1)×100%, where SUV is the standardized uptake value) were also studied and compared with S-factor analysis. RESULTS The best threshold of 0.6 was determined and used to derive AIF. The kinetic model with five parameters yields the best statistical results, but the model with k4=0 was used as the gold standard. All Ki values and some S-factors from data between various intervals (10-30, 10-45, 15-30, 15-45, 20-30, and 20-45 min) fulfilled the criteria. The RIs calculated from the S-factor were highly correlated to RI derived from simple two-point static scans at 10 and 30 min (R=0.9, P<0.0001). CONCLUSION The Patlak graphical analyses and even a 20-min-interval S-factor analysis or simple two-point static scans were shown to be sufficient to characterize NPC metabolism, confirming the clinical feasibility of applying a short dynamic with image-derived AIF or simple two-point static PET scans for studying NPC.
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Arisan V, Karabuda ZC, Pişkin B, Özdemir T. Conventional Multi-Slice Computed Tomography (CT) and Cone-Beam CT (CBCT) for Computer-Aided Implant Placement. Part II: Reliability of Mucosa-Supported Stereolithographic Guides. Clin Implant Dent Relat Res 2012; 15:907-17. [DOI: 10.1111/j.1708-8208.2011.00435.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Image-Derived Arterial Input Function in Dynamic Positron Emission Tomography–Computed Tomography. J Comput Assist Tomogr 2012. [DOI: 10.1097/rct.0b013e31826bdd09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Osman MM, Muzaffar R, Altinyay ME, Teymouri C. FDG Dose Extravasations in PET/CT: Frequency and Impact on SUV Measurements. Front Oncol 2011; 1:41. [PMID: 22655246 PMCID: PMC3356044 DOI: 10.3389/fonc.2011.00041] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 10/17/2011] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Positron emission tomography (PET)/CT with 18F-FDG has proven to be effective in detecting and assessing various types of cancers. However, due to cancer and/or its therapy, intravenous (IV) FDG injection may be problematic resulting in dose extravasations. In the most frequently used field of view (FOV), arms-up, and base of skull to upper thigh [limited whole body (LWB)], the injection site may not be routinely imaged. The purpose of this study was to evaluate the frequency of dose extravasations in FDG PET and the potential impact on standard uptake value (SUV) measurements. METHODS True whole body FDG PET/CT scans (including all extremities) of 400 patients were retrospectively reviewed. A log recorded cases of IV dose extravasations. When possible, SUVs were measured in two frequently used reference locations: mediastinum and liver. The SUVs were obtained in the same patients who had studies with and without FDG extravasations within an average of 3 months without interval therapy. RESULTS Of the 400 scans, 42 (10.5%) had extravasations on the maximum intensity projections images. In scans with or without dose infiltration, FDG injection site was at or distal to the antecubital fossa in 97% of studies. Of those 42 cases, dose infiltration was within the LWB FOV in 29/42 (69%) and outside in the remaining 13/42 (31%). Of those 42 patients, 5 had repeat PET studies with no interval therapy. For those 5 patients, liver maximum SUV was 11.7% less in patients with infiltration than those without (2.22 ± 0.54 vs. 2.48 ± 0.6). Mediastinum SUVmax was 9.3% less in patients with infiltration than those without (1.72 ± 0.54 vs. 1.88 ± 0.49). CONCLUSION We conclude dose extravasations were commonly encountered (10.5%) in PET/CT. However, it is underreported by at least 31% due to omitting injection site from the FOV. When present, extravasations may lead to underestimation of SUVmax. Therefore, it should not only be avoided but also reported in order to avoid false interpretations of the exam.
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Affiliation(s)
- Medhat M. Osman
- Division of Nuclear Medicine, Department of Radiology, Saint Louis UniversitySt. Louis, MO, USA
- Saint Louis VA Medical CenterSt. Louis, MO, USA
| | - Razi Muzaffar
- Division of Nuclear Medicine, Department of Radiology, Saint Louis UniversitySt. Louis, MO, USA
| | - M. Erkan Altinyay
- Division of Nuclear Medicine, Department of Radiology, Saint Louis UniversitySt. Louis, MO, USA
| | - Cyrus Teymouri
- Nuclear Medicine Technology Program, Medical Imaging and Radiation Therapeutics, Doisy College of Health Sciences, Saint Louis UniversitySt. Louis, MO, USA
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Varrone A, Gulyás B, Takano A, Stabin MG, Jonsson C, Halldin C. Simplified quantification and whole-body distribution of [18F]FE-PE2I in nonhuman primates: prediction for human studies. Nucl Med Biol 2011; 39:295-303. [PMID: 22033024 DOI: 10.1016/j.nucmedbio.2011.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 11/20/2022]
Abstract
INTRODUCTION [(18)F]FE-PE2I is a promising dopamine transporter (DAT) radioligand. In nonhuman primates, we examined the accuracy of simplified quantification methods and the estimates of radiation dose of [(18)F]FE-PE2I. METHODS In the quantification study, binding potential (BP(ND)) values previously reported in three rhesus monkeys using kinetic and graphical analyses of [(18)F]FE-PE2I were used for comparison. BP(ND) using the cerebellum as reference region was obtained with four reference tissue methods applied to the [(18)F]FE-PE2I data that were compared with the kinetic and graphical analyses. In the whole-body study, estimates of adsorbed radiation were obtained in two cynomolgus monkeys. RESULTS All reference tissue methods provided BP(ND) values within 5% of the values obtained with the kinetic and graphical analyses. The shortest imaging time for stable BP(ND) estimation was 54 min. The average effective dose of [(18)F]FE-PE2I was 0.021 mSv/MBq, similar to 2-deoxy-2-[(18)F]fluoro-d-glucose. CONCLUSIONS The results in nonhuman primates suggest that [(18)F]FE-PE2I is suitable for accurate and stable DAT quantification, and its radiation dose estimates would allow for a maximal administered radioactivity of 476 MBq in human subjects.
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Affiliation(s)
- Andrea Varrone
- Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, SE-17176 Stockholm, Sweden.
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Cortical-limbic regions modulate depression and anxiety factors in functional dyspepsia: a PET-CT study. Ann Nucl Med 2011; 26:35-40. [PMID: 21953211 DOI: 10.1007/s12149-011-0537-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 09/05/2011] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To observe some specific brain areas or cerebral functional network participating in the modulation of depression and anxiety factors in functional dyspepsia (FD) patients by detecting cerebral glucose metabolism (CGM) in fluorine-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) scans. METHODS Eight FD patients with depression and anxiety (DA-FD group) and eight FD patients without depression and anxiety (non-DA-FD group) were recruited and evaluated by the Nepean Dyspepsia Index (NDI) and Dyspepsia Symptom Scores (DSS). Cerebral (18)F-FDG PET-CT scans were performed on the DA-FD group and non-DA-FD group, respectively. The differences in CGM between the two groups were analyzed with SPM2. RESULTS Extensive changes in the CGM signals were observed in the cerebral cortex and limbic system of FD patients with depression and anxiety. Compared to non-DA-FD patients, DA-FD patients showed a higher glucose metabolism in the right postcentral gyrus (BA 1 and 5), inferior frontal gyrus (BA 45), superior temporal gyrus (BA 22), middle temporal gyrus (BA 22), inferior parietal lobule (BA 40), lingual gyrus (BA 18) and the left middle occipital gyrus (BA 37), as well as the limbic system including the left thalamus, lateral globus pallidus, parahippocampal gyrus (BA 35), right insular cortex (BA 13) and parahippocampal gyrus (BA 18); a lower glucose metabolism was presented in the left middle cingulated gyrus (BA 24), the right superior frontal gyrus (BA 6), the medial frontal gyrus (BA 6) and middle temporal gyrus (BA 21). CONCLUSION An extensive cortical-limbic brain network might modulate the procession of FD patients with depression and anxiety factors.
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Abstract
Neurological imaging represents a powerful paradigm for investigation of brain structure, physiology and function across different scales. The diverse phenotypes and significant normal and pathological brain variability demand reliable and efficient statistical methodologies to model, analyze and interpret raw neurological images and derived geometric information from these images. The validity, reproducibility and power of any statistical brain map require appropriate inference on large cohorts, significant community validation, and multidisciplinary collaborations between physicians, engineers and statisticians.
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Affiliation(s)
- Ivo D Dinov
- SOCR Resource and Laboratory of Neuro Imaging, UCLA Statistics, 8125 Mathematical Science Bldg, Los Angeles, CA 90095, USA, Tel.: +1 310 825 8430
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Basu S, Kwee TC, Surti S, Akin EA, Yoo D, Alavi A. Fundamentals of PET and PET/CT imaging. Ann N Y Acad Sci 2011; 1228:1-18. [DOI: 10.1111/j.1749-6632.2011.06077.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Deron PB, Bonte KM, Vermeersch HF, Van de Wiele C. Lymph node metastasis of squamous cell carcinoma from an unknown primary in the upper and middle neck: Impact of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography. Cancer Biother Radiopharm 2011; 26:331-4. [PMID: 21711095 DOI: 10.1089/cbr.2010.0918] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The purpose of this study was to assess the potential of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging for detection of the primary tumor and its impact on treatment planning in patients presenting with cancer of unknown primary and squamous cell carcinoma (SCC)-positive cervical lymph nodes of the upper and middle neck. METHODS The study population consisted of 18 consecutive patients with biopsy-proven SCC involving lymph nodes of the upper and middle neck region and negative conventional diagnostic procedures with regard to the location of the primary. All patients underwent FDG-PET/CT according to a standard procedure in search for the primary, unidentified tumor. RESULTS In none of the patients FDG-PET/CT was able to indicate a primary tumor localization. Although FDG-PET/CT did identify all sites of known lymph node involvement, neither additional sites of lymph node involvement nor sites of distant metastases were identified. Accordingly, FDG-PET/CT did not impact patient treatment planning. CONCLUSIONS In this series, including patients suffering from lymph node metastases by an SCC of unknown primary in the upper and middle neck, FDG-PET/CT was unable to identify a primary tumor. In addition, FDG-PET/CT did not modify the treatment planning in any of the patients studied.
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Affiliation(s)
- Philippe B Deron
- Department of Head and Neck Surgery, University Hospital Ghent, Belgium.
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McDermott G, Iball G, Scarsbrook A. The potential pitfalls of low-activity protocols in PET/CT imaging. Eur J Nucl Med Mol Imaging 2011; 38:185-7; author reply 188-9. [PMID: 21061119 DOI: 10.1007/s00259-010-1649-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 10/06/2010] [Indexed: 11/25/2022]
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Peremans K, Vermeire S, Dobbeleir A, Gielen I, Samoy Y, Piron K, Vandermeulen E, Slegers G, van Bree H, De Spiegeleer B, Dik K. Recognition of anatomical predilection sites in canine elbow pathology on bone scans using micro-single photon emission tomography. Vet J 2011; 188:64-72. [DOI: 10.1016/j.tvjl.2010.02.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 02/17/2010] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
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Del Vecchio S, Zannetti A, Fonti R, Iommelli F, Pizzuti LM, Lettieri A, Salvatore M. PET/CT in cancer research: from preclinical to clinical applications. CONTRAST MEDIA & MOLECULAR IMAGING 2011; 5:190-200. [PMID: 20812287 DOI: 10.1002/cmmi.368] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The identification of genetic and biochemical mechanisms underlying tumor growth and progression along with the unraveling of human genoma provided a plethora of new targets for cancer detection, treatment and monitoring. Simultaneously, the extraordinary development of a number of imaging technologies, including hybrid systems, allowed the visualization of biochemical, molecular and physiological aberrations linked to underlying mutations in a given tumor. In vivo evaluation of complex biological processes such as proliferation, apoptosis, angiogenesis, metastasis, gene expression, receptor-ligand interactions, transport of substrates and metabolism of nutrients in human cancers is feasible using PET/CT and radiolabeled molecular probes. Some of these compounds are in preclinical phases of evaluation whereas others have been already applied in clinical settings. Here we provide prominent examples on how some biological processes and target expression can be visualized by PET/CT in animal tumor models and cancer patients for the noninvasive detection of well-known markers of tumor aggressiveness, invasiveness and resistance to treatment and for the evaluation of tumor response to therapy.
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Affiliation(s)
- S Del Vecchio
- Department of Biomorphological and Functional Sciences, University of Naples Federico II, Naples, Italy.
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Natoli C, Ramazzotti V, Nappi O, Giacomini P, Palmeri S, Salvatore M, Landriscina M, Zilli M, Natali PG, Tinari N, Iacobelli S. Unknown primary tumors. Biochim Biophys Acta Rev Cancer 2011; 1816:13-24. [PMID: 21371531 DOI: 10.1016/j.bbcan.2011.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 02/17/2011] [Accepted: 02/19/2011] [Indexed: 12/27/2022]
Abstract
An unknown primary tumor (UPT) is defined by the presence of a metastatic cancer without a known primary site of origin despite a standardized diagnostic workup. Clinically, UPTs show rapid progression and early dissemination, with signs and symptoms related to the metastatic site. The molecular bases of their biology remain largely unknown, with no evidence as to whether they represent a distinct biological entity. Immunohistochemistry remain the best diagnostic tool in term of cost-effectiveness, but the time-consuming "algorithmic process" it relies on has led to the application of new molecular techniques for the identification of the primary site of UPTs. For example, several microarray or miRNA classifications of UPTs have been used, with an accuracy in the prediction of the primary site as high as 90%. It should be noted that validating a prediction of tissue origin is challenging in these patients, since most of them will never have a primary site identified. Moreover, prospective studies to determine whether selection of treatment options based on such profiling methods actually improves patient outcome are still missing. In the last few years functional imaging (i.e. FDG-PET/CT) has gained a main role in the detection of the site of origin of UPTs and is currently recommended by the European Association of Nuclear Medicine. However, despite recent refinements in the diagnostic workup, the site of origin of UPT often remains elusive. As a consequence, treatment of patients with UPT is still empirical and inadequate.
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Affiliation(s)
- C Natoli
- Unit of Medical Oncology, Department of Oncology and Experimental Medicine and CeSI, Fondazione 'G. D' Annunzio', University of Chieti-Pescara, 66100 Chieti, Italy.
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18F-FDG PET/CT of patients with cancer: comparison of whole-body and limited whole-body technique. AJR Am J Roentgenol 2011; 195:1397-403. [PMID: 21098201 DOI: 10.2214/ajr.09.3731] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Use of the routine field of view for whole-body (18)F-FDG PET/CT can lead to underestimation of the true extent of the disease because metastasis outside the typical base of skull to upper thigh field of view can be missed. The purpose of this study was to evaluate the incremental added value of true whole-body as opposed to this limited whole-body PET/CT of cancer patients. MATERIALS AND METHODS True whole-body FDG PET/CT, from the top of the skull to the bottom of the feet, was performed on 500 consecutively registered patients. A log was kept of cases of suspected malignancy outside the typical limited whole-body field of view. Suspected lesions in the brain, skull, and extremities were verified by correlation with surgical pathologic or clinical follow-up findings. RESULTS Fifty-nine of 500 patients had PET/CT findings suggestive of malignancy outside the limited whole-body field of view. Thirty-one of those patients had known or suspected malignancy outside the limited whole-body field of view at the time of the true whole-body study. Among the other 28 patients, follow-up data were not available for two, six had false-positive findings, and new cancerous involvement was confirmed in 20. Detection of malignancy outside the limited whole-body field of view resulted in a change in management in 65% and in staging in 55% of the 20 cases. CONCLUSION Our study showed that 20 of 500 (4.0%) of patients had previously unsuspected malignancy outside the typical limited whole-body field of view. Detection of such malignancy resulted in a change in management in 13 of 500 cases (2.6%). We propose that adopting a true whole-body field of view in the imaging of cancer patients may lead to more accurate staging and restaging than achieved with the routinely used limited whole-body field of view.
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Lawrence J, Rohren E, Provenzale J. PET/CT today and tomorrow in veterinary cancer diagnosis and monitoring: fundamentals, early results and future perspectives. Vet Comp Oncol 2010; 8:163-87. [PMID: 20691025 DOI: 10.1111/j.1476-5829.2010.00218.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Functional imaging using positron emission tomography (PET) plays an important role in the diagnosis, staging, image-guided treatment planning and monitoring of malignant diseases. PET imaging complements conventional anatomical imaging such as computed tomography (CT) and magnetic resonance imaging (MRI). The strength of CT scanning lies in its high spatial resolution, allowing for anatomical characterization of disease. PET imaging, however, moves beyond anatomy and characterizes tissue based on functions such as metabolic rate. Combined PET/CT scanners were introduced commercially in 2001 and a number of technological advancements have since occurred. Radiolabelled tracers such as (18)F-fluorodeoxyglucose (FDG) and (18)F-fluorothymidine (FLT) allow visualization of various metabolic processes within cancer cells. Many studies in human oncology evaluating the utility of PET/CT have demonstrated clinical benefits. Few veterinary studies have been performed, but initial studies show promise for improved detection of malignancy, more thorough staging of canine cancer and determination of early response and disease recrudescence.
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Affiliation(s)
- J Lawrence
- Department of Small Animal Medicine and Surgery, University of Georgia, College of Veterinary Medicine, Athens, GA 30602, USA.
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Hricak H, Choi BI, Scott AM, Sugimura K, Muellner A, von Schulthess GK, Reiser MF, Graham MM, Dunnick NR, Larson SM. Global trends in hybrid imaging. Radiology 2010; 257:498-506. [PMID: 20829539 DOI: 10.1148/radiol.10100579] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
At the 2009 Scientific Assembly and Annual Meeting of the Radiological Society of North America, a special session was devoted to global trends in hybrid imaging. This article expands on the key points of the session, focusing primarily on positron emission tomography/computed tomography. Global trends in hybrid imaging equipment acquisition, usage, and image interpretation practices are reviewed, and emerging requirements for training and clinical privileging are discussed. Also considered are the current benefits of hybrid imaging for patient care and workflow and the potential of hybrid imaging for advancing drug development and personalized medicine.
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Affiliation(s)
- Hedvig Hricak
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Room C-278, New York, NY 10065, USA
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