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Bernsen MR, Vaissier PEB, Van Holen R, Booij J, Beekman FJ, de Jong M. The role of preclinical SPECT in oncological and neurological research in combination with either CT or MRI. Eur J Nucl Med Mol Imaging 2014; 41 Suppl 1:S36-49. [PMID: 24895751 PMCID: PMC4003405 DOI: 10.1007/s00259-013-2685-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 01/03/2023]
Abstract
Preclinical imaging with SPECT combined with CT or MRI is used more and more frequently and has proven to be very useful in translational research. In this article, an overview of current preclinical research applications and trends of SPECT combined with CT or MRI, mainly in tumour imaging and neuroscience imaging, is given and the advantages and disadvantages of the different approaches are described. Today SPECT and CT systems are often integrated into a single device (commonly called a SPECT/CT system), whereas at present combined SPECT and MRI is almost always carried out with separate systems and fiducial markers to combine the separately acquired images. While preclinical SPECT/CT is most widely applied in oncology research, SPECT combined with MRI (SPECT/MRI when integrated in one system) offers the potential for both neuroscience applications and oncological applications. Today CT and MRI are still mainly used to localize radiotracer binding and to improve SPECT quantification, although both CT and MRI have additional potential. Future technology developments may include fast sequential or simultaneous acquisition of (dynamic) multimodality data, spectroscopy, fMRI along with high-resolution anatomic MRI, advanced CT procedures, and combinations of more than two modalities such as combinations of SPECT, PET, MRI and CT all together. This will all strongly depend on new technologies. With further advances in biology and chemistry for imaging molecular targets and (patho)physiological processes in vivo, the introduction of new imaging procedures and promising new radiopharmaceuticals in clinical practice may be accelerated.
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Affiliation(s)
- Monique R. Bernsen
- Department of Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiology, Erasmus MC, Rotterdam, The Netherlands
| | - Pieter E. B. Vaissier
- Section Radiation Detection and Medical Imaging, Delft University of Technology, Delft, The Netherlands
| | - Roel Van Holen
- ELIS Department, MEDISIP, Ghent University, iMinds, Ghent, Belgium
| | - Jan Booij
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Freek J. Beekman
- Section Radiation Detection and Medical Imaging, Delft University of Technology, Delft, The Netherlands
- MILabs B.V., Utrecht, The Netherlands
| | - Marion de Jong
- Department of Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiology, Erasmus MC, Rotterdam, The Netherlands
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53
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Tian J, Fu L, Yin D, Zhang J, Chen Y, An N, Xu B. Does the novel integrated PET/MRI offer the same diagnostic performance as PET/CT for oncological indications? PLoS One 2014; 9:e90844. [PMID: 24603857 PMCID: PMC3946212 DOI: 10.1371/journal.pone.0090844] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 02/04/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND We compared PET/MRI with PET/CT in terms of lesion detection and quantitative measurement to verify the feasibility of the novel integrated imaging modality for oncological applications. METHODOLOGY/PRINCIPAL FINDINGS In total, 285 patients referred to our PET/CT center for oncological indications voluntarily participated in this same-day PET/CT and PET/MRI comparative study. PET/CT images were acquired and reconstructed following routine protocols, and then PET/MRI was performed at a mean time interval of 28±11 min (range 15-45 min). PET/MRI covered the body trunk with a sequence combination of transverse T1WI 3D-volumetric interpolated breath-hold, T2WI turbo spin echo with fat saturation, diffusion-weighted imaging with double b values (50 and 800 s/mm2), and simultaneous PET acquisition over 45 min/5 bed positions. The maximum standardized uptake value (SUVmax) was assessed by manually drawn regions of interest over fluorodeoxyglucose-positive lesions. Among 285 cases, 57 showed no abnormalities, and 368 lesions (278 malignant, 68 benign and 22 undetermined) were detected in 228 patients. When stand-alone modalities were evaluated, PET revealed 31 and 12 lesions missed by CT and MRI, respectively, and CT and MRI revealed 38 and 61 more lesions, respectively, than PET. Compared to CT, MRI detected 40 more lesions and missed 8. In the integrated mode, PET/CT correctly detected 6 lesions misdiagnosed by PET/MRI, but was false-negative in 30 cases that were detected by PET/MRI. The overall diagnosis did not differ between integrated PET/MRI and PET/CT. SUVmax for lesions were slightly higher from PET/MRI than PET/CT but correlated well (ρ = 0.85-0.91). CONCLUSIONS/SIGNIFICANCE The novel integrated PET/MRI performed comparatively to PET/CT in lesion detection and quantitative measurements. PET from either scanner modality offered almost the same information despite differences in hardware. Further study is needed to explore features of integrated PET/MRI not addressed in this study.
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Affiliation(s)
- Jiahe Tian
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Beijing, China
- * E-mail:
| | - Liping Fu
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Beijing, China
| | - Dayi Yin
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Beijing, China
| | - Jinming Zhang
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Beijing, China
| | - Yingmao Chen
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Beijing, China
| | - Ningyu An
- Department of Radiology, Xiyuan, General Hospital of the Chinese People's Liberation Army, Beijing, China
| | - Baixuan Xu
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Beijing, China
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Garofalakis A, Dubois A, Thézé B, Czarny B, Tavitian B, Ducongé F. Fusion of [(18)F]FDG PET with fluorescence diffuse optical tomography to improve validation of probes and tumor imaging. Mol Imaging Biol 2014; 15:316-25. [PMID: 22927057 PMCID: PMC3647087 DOI: 10.1007/s11307-012-0581-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Purpose Given the progress of fluorescence diffuse optical tomography (fDOT) technology, here, we study the additional benefits provided by multimodal PET/fDOT imaging by comparing the biodistribution of 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) in tumors with three fluorescent probes: a glucose analog, a protease activatable optical probe, and a ligand of αvβ3 integrin. Procedures Sequential fDOT/PET/computed tomography (CT) imaging of mice was performed with a custom multimodal mouse support that allows the subject to be transferred between the fDOT and the PET/CT scanners. Experiments were performed in xenografted tumor models derived from the human breast cancer line MDA-MB 231 and compared to ex vivo analysis. Results The three-dimensional signals showed that the fluorescent glucose analog is not colocalized with [18F]FDG, raising questions about its use as a surrogate probe of the PET tracer. Fusion of [18F]FDG with the other fluorescent probes showed evidence of high variability both for the protease activity and the αvβ3 integrin expression during tumor growth. Conclusion The added value of hybrid PET/fDOT over the two modalities was demonstrated for cross-validation of probes and for better characterization of tumor models.
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Affiliation(s)
- Anikitos Garofalakis
- CEA, Institut d'Imagerie Biomédicale, Service Hospitalier Frédéric Joliot, Orsay Cedex, France
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El-Ghussein F, Jiang S, Pogue BW, Paulsen KD. Comparison of magnetic resonance imaging-compatible optical detectors for in-magnet tissue spectroscopy: photodiodes versus silicon photomultipliers. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:070502. [PMID: 25006986 PMCID: PMC4160972 DOI: 10.1117/1.jbo.19.7.070502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/12/2014] [Accepted: 06/16/2014] [Indexed: 06/03/2023]
Abstract
Tissue spectroscopy inside the magnetic resonance imaging (MRI) system adds a significant value by measuring fast vascular hemoglobin responses or completing spectroscopic identification of diagnostically relevant molecules. Advances in this type of spectroscopy instrumentation have largely focused on fiber coupling into and out of the MRI; however, nonmagnetic detectors can now be placed inside the scanner with signal amplification performed remotely to the high field environment for optimized light detection. In this study, the two possible detector options, such as silicon photodiodes (PD) and silicon photomultipliers (SiPM), were systematically examined for dynamic range and wavelength performance. Results show that PDs offer 10⁸(160 dB) dynamic range with sensitivity down to 1 pW, whereas SiPMs have 10⁷(140 dB) dynamic range and sensitivity down to 10 pW. A second major difference is the spectral sensitivity of the two detectors. Here, wavelengths in the 940 nm range are efficiently captured by PDs (but not SiPMs), likely making them the superior choice for broadband spectroscopy guided by MRI.
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Affiliation(s)
- Fadi El-Ghussein
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire 03755, United States
| | - Shudong Jiang
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire 03755, United States
| | - Brian W. Pogue
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire 03755, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire 03755, United States
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Velikyan I. Prospective of ⁶⁸Ga-radiopharmaceutical development. Theranostics 2013; 4:47-80. [PMID: 24396515 PMCID: PMC3881227 DOI: 10.7150/thno.7447] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/01/2013] [Indexed: 01/29/2023] Open
Abstract
Positron Emission Tomography (PET) experienced accelerated development and has become an established method for medical research and clinical routine diagnostics on patient individualized basis. Development and availability of new radiopharmaceuticals specific for particular diseases is one of the driving forces of the expansion of clinical PET. The future development of the ⁶⁸Ga-radiopharmaceuticals must be put in the context of several aspects such as role of PET in nuclear medicine, unmet medical needs, identification of new biomarkers, targets and corresponding ligands, production and availability of ⁶⁸Ga, automation of the radiopharmaceutical production, progress of positron emission tomography technologies and image analysis methodologies for improved quantitation accuracy, PET radiopharmaceutical regulations as well as advances in radiopharmaceutical chemistry. The review presents the prospects of the ⁶⁸Ga-based radiopharmaceutical development on the basis of the current status of these aspects as well as wide range and variety of imaging agents.
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Affiliation(s)
- Irina Velikyan
- 1. Preclinical PET Platform, Department of Medicinal Chemistry, Uppsala University, SE-75183 Uppsala, Sweden
- 2. PET-Centre, Centre for Medical Imaging, Uppsala University Hospital, SE-75185, Uppsala, Sweden
- 3. Department of Radiology, Oncology, and Radiation Science, Uppsala University, SE-75285 Uppsala, Sweden
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Yang X, Fei B. Multiscale segmentation of the skull in MR images for MRI-based attenuation correction of combined MR/PET. J Am Med Inform Assoc 2013; 20:1037-45. [PMID: 23761683 PMCID: PMC3822115 DOI: 10.1136/amiajnl-2012-001544] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 05/03/2013] [Accepted: 05/23/2013] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Combined magnetic resonance/positron emission tomography (MR/PET) is a relatively new, hybrid imaging modality. MR-based attenuation correction often requires segmentation of the bone on MR images. In this study, we present an automatic segmentation method for the skull on MR images for attenuation correction in brain MR/PET applications. MATERIALS AND METHODS Our method transforms T1-weighted MR images to the Radon domain and then detects the features of the skull image. In the Radon domain we use a bilateral filter to construct a multiscale image series. For the repeated convolution we increase the spatial smoothing in each scale and make the width of the spatial and range Gaussian function doubled in each scale. Two filters with different kernels along the vertical direction are applied along the scales from the coarse to fine levels. The results from a coarse scale give a mask for the next fine scale and supervise the segmentation in the next fine scale. The use of the multiscale bilateral filtering scheme is to improve the robustness of the method for noise MR images. After combining the two filtered sinograms, the reciprocal binary sinogram of the skull is obtained for the reconstruction of the skull image. RESULTS This method has been tested with brain phantom data, simulated brain data, and real MRI data. For real MRI data the Dice overlap ratios are 92.2%±1.9% between our segmentation and manual segmentation. CONCLUSIONS The multiscale segmentation method is robust and accurate and can be used for MRI-based attenuation correction in combined MR/PET.
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Affiliation(s)
- Xiaofeng Yang
- Department of Radiology and Imaging Sciences, Center for Systems Imaging, Emory University, Atlanta, Georgia, USA
| | - Baowei Fei
- Department of Radiology and Imaging Sciences, Center for Systems Imaging, Emory University, Atlanta, Georgia, USA
- Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia, USA
- Winship Cancer Institute of Emory University, Atlanta, Georgia, USA
- Department of Mathematics and Computer Science, Emory University, Atlanta, Georgia, USA
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Characterisation of solitary pulmonary lesions combining visual perfusion and quantitative diffusion MR imaging. Eur Radiol 2013; 24:531-41. [PMID: 24173597 DOI: 10.1007/s00330-013-3053-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 09/14/2013] [Accepted: 10/08/2013] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To evaluate the diagnostic accuracy of dynamic contrast-enhanced (DCE) magnetic resonance (MR) and diffusion-weighted imaging (DWI) sequences for defining benignity or malignancy of solitary pulmonary lesions (SPL). METHODS First, 54 consecutive patients with SPL, clinically staged (CT and PET or integrated PET-CT) as N0M0, were included in this prospective study. An additional 3-Tesla MR examination including DCE and DWI was performed 1 day before the surgical procedure. Histopathology of the surgical specimen served as the standard of reference. Subsequently, this functional method of SPL characterisation was validated with a second cohort of 54 patients. RESULTS In the feasibility group, 11 benign and 43 malignant SPL were included. Using the combination of conventional MR sequences with visual interpretation of DCE-MR curves resulted in a sensitivity, specificity and accuracy of 100%, 55% and 91%, respectively. These results can be improved by DWI (with a cut-off value of 1.52 × 10(-3) mm(2)/s for ADChigh) leading to a sensitivity, specificity and accuracy of 98%, 82% and 94%, respectively. In the validation group these results were confirmed. CONCLUSION Visual DCE-MR-based curve interpretation can be used for initial differentiation of benign from malignant SPL, while additional quantitative DWI-based interpretation can further improve the specificity. KEY POINTS • Magnetic resonance imaging is increasingly being used to help differentiate lung lesions. • Solitary pulmonary lesions (SPL) are accurately characterised by combining DCE-MRI and DWI. • Visual DCE-MRI assessment facilitates the diagnostic throughput in patients with SPL. • DWI provides additional information in inconclusive DCE-MRI (type B pattern).
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Multimodality PET/MRI agents targeted to activated macrophages. J Biol Inorg Chem 2013; 19:247-58. [PMID: 24166283 DOI: 10.1007/s00775-013-1054-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 10/08/2013] [Indexed: 12/18/2022]
Abstract
The recent emergence of multimodality imaging, particularly the combination of PET and MRI, has led to excitement over the prospect of improving detection of disease. Iron oxide nanoparticles have become a popular platform for the fabrication of PET/MRI probes owing to their advantages of high MRI detection sensitivity, biocompatibility, and biodegradability. In this article, we report the synthesis of dextran-coated iron oxide nanoparticles (DIO) labeled with the positron emitter (64)Cu to generate a PET/MRI probe, and modified with maleic anhydride to increase the negative surface charge. The modified nanoparticulate PET/MRI probe (MDIO-(64)Cu-DOTA) bears repetitive anionic charges on the surface that facilitate recognition by scavenger receptor type A (SR-A), a ligand receptor found on activated macrophages but not on normal vessel walls. MDIO-(64)Cu-DOTA has an average iron oxide core size of 7-8 nm, an average hydrodynamic diameter of 62.7 nm, an r1 relaxivity of 16.8 mM(-1) s(-1), and an r 2 relaxivity of 83.9 mM(-1) s(-1) (37 °C, 1.4 T). Cell studies confirmed that the probe was nontoxic and was specifically taken up by macrophages via SR-A. In comparison with the nonmodified analog, the accumulation of MDIO in macrophages was substantially improved. These characteristics demonstrate the promise of MDIO-(64)Cu-DOTA for identification of vulnerable atherosclerotic plaques via the targeting of macrophages.
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Neuner I, Arrubla J, Felder J, Shah NJ. Simultaneous EEG-fMRI acquisition at low, high and ultra-high magnetic fields up to 9.4 T: perspectives and challenges. Neuroimage 2013; 102 Pt 1:71-9. [PMID: 23796544 DOI: 10.1016/j.neuroimage.2013.06.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 01/25/2023] Open
Abstract
In this perspectives article we highlight the advantages of simultaneous acquisition of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). As MRI moves towards using ultra-high magnetic fields in the quest for increased signal-to-noise, the question arises whether combined EEG-fMRI measurements are feasible at magnetic fields of 7 T and higher. We describe the challenges of MRI-EEG at 1.5, 3, 7 and 9.4 T and review the proposed solutions. In an outlook, we discuss further developments such as simultaneous trimodal imaging using MR, positron emission tomography (PET) and EEG under the same physiological conditions in the same subject.
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Affiliation(s)
- Irene Neuner
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Germany; JARA - BRAIN - Translational Medicine, Germany.
| | - Jorge Arrubla
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany
| | - Jörg Felder
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany; Department of Neurology, RWTH Aachen University, Germany; JARA - BRAIN - Translational Medicine, Germany
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Jadvar H, Colletti PM. Competitive advantage of PET/MRI. Eur J Radiol 2013; 83:84-94. [PMID: 23791129 DOI: 10.1016/j.ejrad.2013.05.028] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 05/20/2013] [Accepted: 05/20/2013] [Indexed: 02/08/2023]
Abstract
Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.
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Affiliation(s)
- Hossein Jadvar
- Division of Nuclear Medicine, Department of Radiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA.
| | - Patrick M Colletti
- Division of Nuclear Medicine, Department of Radiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
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Pace L, Nicolai E, Aiello M, Catalano OA, Salvatore M. Whole-body PET/MRI in oncology: current status and clinical applications. Clin Transl Imaging 2013. [DOI: 10.1007/s40336-013-0012-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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63
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Wehrl HF, Schwab J, Hasenbach K, Reischl G, Tabatabai G, Quintanilla-Martinez L, Jiru F, Chughtai K, Kiss A, Cay F, Bukala D, Heeren RMA, Pichler BJ, Sauter AW. Multimodal elucidation of choline metabolism in a murine glioma model using magnetic resonance spectroscopy and 11C-choline positron emission tomography. Cancer Res 2013; 73:1470-80. [PMID: 23345160 DOI: 10.1158/0008-5472.can-12-2532] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The metabolites, transporters, and enzymes involved in choline metabolism are regarded as biomarkers for disease progression in a variety of cancers, but their in vivo detection is not ideal. Both magnetic resonance spectroscopy [MRS using chemical shift imaging (CSI) total choline (tCho)] and C-choline positron emission tomography (PET) can probe this pathway, but they have not been compared side by side. In this study, we used the spontaneous murine astrocytoma model SMA560 injected intracranially into syngeneic VM/Dk mice, analyzing animals at various postimplantation time points using dynamic microPET imaging and CSI MRS. We observed an increase in tumor volume and C-choline uptake between days 5 and 18. Similarly, tCho levels decreased at days 5 to 18. We found a negative correlation between the tCho and PET results in the tumor and a positive correlation between the tCho tumor-to-brain ratio and choline uptake in the tumor. PCR results confirmed expected increases in expression levels for most of the transporters and enzymes. Using MRS quantification, a good agreement was found between CSI and C-choline PET data, whereas a negative correlation occurred when CSI was not referenced. Thus, C-choline PET and MRS methods seemed to be complementary in strengths. While advancing tumor proliferation caused an increasing C-choline uptake, gliosis and inflammation potentially accounted for a high peritumoral tCho signal in CSI, as supported by histology and secondary ion mass spectrometry imaging. Our findings provide definitive evidence of the use of MRS, CSI, and PET for imaging tumors in vivo.
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Affiliation(s)
- Hans F Wehrl
- Werner Siemens Imaging Center,Roentgenweg 13, Tuebingen, Germany
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Yang M, Cheng K, Qi S, Liu H, Jiang Y, Jiang H, Li J, Chen K, Zhang H, Cheng Z. Affibody modified and radiolabeled gold-iron oxide hetero-nanostructures for tumor PET, optical and MR imaging. Biomaterials 2013; 34:2796-806. [PMID: 23343632 DOI: 10.1016/j.biomaterials.2013.01.014] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/03/2013] [Indexed: 12/23/2022]
Abstract
A highly monodispersed hetero-nanostructure with two different functional nanomaterials (gold (Au) and iron oxide (Fe(3)O(4,) IO)) within one structure was successfully developed as Affibody based trimodality nanoprobe (positron emission tomography, PET; optical imaging; and magnetic resonance imaging, MRI) for imaging of epidermal growth factor receptor (EGFR) positive tumors. Unlike other regular nanostructures with a single component, the Au-IO hetero-nanostructures (Au-IONPs) with unique chemical and physical properties have capability to combine several imaging modalities together to provide complementary information. The IO component within hetero-nanostructures serve as a T(2) reporter for MRI; and gold component serve as both optical and PET reporters. Moreover, such hetero-nanoprobes could provide a robust nano-platform for surface-specific modification with both targeting molecules (anti-EGFR Affibody protein) and PET imaging reporters (radiometal (64)Cu chelators) in highly efficient and reliable manner. In vitro and in vivo study showed that the resultant nanoprobe provided high specificity, sensitivity, and excellent tumor contrast for both PET and MRI imaging in the human EGFR-expressing cells and tumors. Our study data also highlighted the EGFR targeting efficiency of hetero-nanoparticles and the feasibility for their further theranostic applications.
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Affiliation(s)
- Meng Yang
- Department of Diagnostic Ultrasound, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
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Majmudar MD, Yoo J, Keliher EJ, Truelove JJ, Iwamoto Y, Sena B, Dutta P, Borodovsky A, Fitzgerald K, Di Carli MF, Libby P, Anderson DG, Swirski FK, Weissleder R, Nahrendorf M. Polymeric nanoparticle PET/MR imaging allows macrophage detection in atherosclerotic plaques. Circ Res 2013; 112:755-61. [PMID: 23300273 DOI: 10.1161/circresaha.111.300576] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Myeloid cell content in atherosclerotic plaques associates with rupture and thrombosis. Thus, imaging of lesional monocytes and macrophages could serve as a biomarker of disease progression and therapeutic intervention. OBJECTIVE To noninvasively assess plaque inflammation with dextran nanoparticle (DNP)-facilitated hybrid positron emission tomography/magnetic resonance imaging (PET/MRI). METHODS AND RESULTS Using clinically approved building blocks, we systematically developed 13-nm polymeric nanoparticles consisting of cross-linked short chain dextrans, which were modified with desferoxamine for zirconium-89 radiolabeling ((89)Zr-DNP) and a near-infrared fluorochrome (VT680) for microscopic and cellular validation. Flow cytometry of cells isolated from excised aortas showed DNP uptake predominantly in monocytes and macrophages (76.7%) and lower signal originating from other leukocytes, such as neutrophils and lymphocytes (11.8% and 0.7%, P<0.05 versus monocytes and macrophages). DNP colocalized with the myeloid cell marker CD11b on immunohistochemistry. PET/MRI revealed high uptake of (89)Zr-DNP in the aortic root of apolipoprotein E knock out (ApoE(-/-)) mice (standard uptake value, ApoE(-/-) mice versus wild-type controls, 1.9±0.28 versus 1.3±0.03; P<0.05), corroborated by ex vivo scintillation counting and autoradiography. Therapeutic silencing of the monocyte-recruiting receptor C-C chemokine receptor type 2 with short-interfering RNA decreased (89)Zr-DNP plaque signal (P<0.05) and inflammatory gene expression (P<0.05). CONCLUSIONS Hybrid PET/MRI with a 13-nm DNP enables noninvasive assessment of inflammation in experimental atherosclerotic plaques and reports on therapeutic efficacy of anti-inflammatory therapy.
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Affiliation(s)
- Maulik D Majmudar
- Center for Systems Biology, Massachusetts General Hospital, 185 Cambridge St., Boston, MA 02114, USA
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Prospective interest of molecular neuroimaging in Alzheimer's disease. Rev Neurol (Paris) 2013; 169:9-13. [DOI: 10.1016/j.neurol.2012.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 03/16/2012] [Accepted: 03/20/2012] [Indexed: 11/23/2022]
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Hirsch FW, Sattler B, Sorge I, Kurch L, Viehweger A, Ritter L, Werner P, Jochimsen T, Barthel H, Bierbach U, Till H, Sabri O, Kluge R. PET/MR in children. Initial clinical experience in paediatric oncology using an integrated PET/MR scanner. Pediatr Radiol 2013; 43:860-75. [PMID: 23306377 PMCID: PMC3691480 DOI: 10.1007/s00247-012-2570-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 10/04/2012] [Accepted: 10/06/2012] [Indexed: 01/04/2023]
Abstract
Use of PET/MR in children has not previously been reported, to the best of our knowledge. Children with systemic malignancies may benefit from the reduced radiation exposure offered by PET/MR. We report our initial experience with PET/MR hybrid imaging and our current established sequence protocol after 21 PET/MR studies in 15 children with multifocal malignant diseases. The effective dose of a PET/MR scan was only about 20% that of the equivalent PET/CT examination. Simultaneous acquisition of PET and MR data combines the advantages of the two previously separate modalities. Furthermore, the technique also enables whole-body diffusion-weighted imaging (DWI) and statements to be made about the biological cellularity and nuclear/cytoplasmic ratio of tumours. Combined PET/MR saves time and resources. One disadvantage of PET/MR is that in order to have an effect, a significantly longer examination time is needed than with PET/CT. In our initial experience, PET/MR has turned out to be an unexpectedly stable and reliable hybrid imaging modality, which generates a complementary diagnostic study of great additional value.
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Affiliation(s)
- Franz Wolfgang Hirsch
- Department of Paediatric Radiology, University of Leipzig, Liebigstr. 20a, 04103, Leipzig, Germany.
| | - Bernhard Sattler
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
| | - Ina Sorge
- Department of Paediatric Radiology, University of Leipzig, Liebigstr. 20a, 04103 Leipzig, Germany
| | - Lars Kurch
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
| | - Adrian Viehweger
- Department of Paediatric Radiology, University of Leipzig, Liebigstr. 20a, 04103 Leipzig, Germany
| | - Lutz Ritter
- Department of Paediatric Radiology, University of Leipzig, Liebigstr. 20a, 04103 Leipzig, Germany
| | - Peter Werner
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
| | - Thies Jochimsen
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
| | - Uta Bierbach
- Department of Paediatric Oncology, University of Leipzig, Liebigstr. 20a, 04103 Leipzig, Germany
| | - Holger Till
- Department of Paediatric Surgery, University of Leipzig, Liebigstr. 20a, 04103 Leipzig, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
| | - Regine Kluge
- Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany
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68
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Fei B, Yang X, Nye JA, Aarsvold JN, Raghunath N, Cervo M, Stark R, Meltzer CC, Votaw JR. MR∕PET quantification tools: registration, segmentation, classification, and MR-based attenuation correction. Med Phys 2012; 39:6443-54. [PMID: 23039679 PMCID: PMC3477199 DOI: 10.1118/1.4754796] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/27/2012] [Accepted: 09/11/2012] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Combined MR∕PET is a relatively new, hybrid imaging modality. A human MR∕PET prototype system consisting of a Siemens 3T Trio MR and brain PET insert was installed and tested at our institution. Its present design does not offer measured attenuation correction (AC) using traditional transmission imaging. This study is the development of quantification tools including MR-based AC for quantification in combined MR∕PET for brain imaging. METHODS The developed quantification tools include image registration, segmentation, classification, and MR-based AC. These components were integrated into a single scheme for processing MR∕PET data. The segmentation method is multiscale and based on the Radon transform of brain MR images. It was developed to segment the skull on T1-weighted MR images. A modified fuzzy C-means classification scheme was developed to classify brain tissue into gray matter, white matter, and cerebrospinal fluid. Classified tissue is assigned an attenuation coefficient so that AC factors can be generated. PET emission data are then reconstructed using a three-dimensional ordered sets expectation maximization method with the MR-based AC map. Ten subjects had separate MR and PET scans. The PET with [(11)C]PIB was acquired using a high-resolution research tomography (HRRT) PET. MR-based AC was compared with transmission (TX)-based AC on the HRRT. Seventeen volumes of interest were drawn manually on each subject image to compare the PET activities between the MR-based and TX-based AC methods. RESULTS For skull segmentation, the overlap ratio between our segmented results and the ground truth is 85.2 ± 2.6%. Attenuation correction results from the ten subjects show that the difference between the MR and TX-based methods was <6.5%. CONCLUSIONS MR-based AC compared favorably with conventional transmission-based AC. Quantitative tools including registration, segmentation, classification, and MR-based AC have been developed for use in combined MR∕PET.
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Affiliation(s)
- Baowei Fei
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA.
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69
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Affiliation(s)
- Wolf-Dieter Heiss
- From the Max Planck Institute for Neurological Research, Cologne, Germany
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70
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Feasibility of Sequential PET/MRI Using a State-of-the-Art Small Animal PET and a 1 T Benchtop MRI. Mol Imaging Biol 2012; 15:155-65. [DOI: 10.1007/s11307-012-0577-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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71
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Neuner I, Kaffanke JB, Langen KJ, Kops ER, Tellmann L, Stoffels G, Weirich C, Filss C, Scheins J, Herzog H, Shah NJ. Multimodal imaging utilising integrated MR-PET for human brain tumour assessment. Eur Radiol 2012; 22:2568-80. [PMID: 22777617 DOI: 10.1007/s00330-012-2543-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 04/27/2012] [Accepted: 05/09/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVES The development of integrated magnetic resonance (MR)-positron emission tomography (PET) hybrid imaging opens up new horizons for imaging in neuro-oncology. In cerebral gliomas the definition of tumour extent may be difficult to ascertain using standard MR imaging (MRI) only. The differentiation of post-therapeutic scar tissue, tumour rests and tumour recurrence is challenging. The relationship to structures such as the pyramidal tract to the tumour mass influences the therapeutic neurosurgical approach. METHODS The diagnostic information may be enriched by sophisticated MR techniques such as diffusion tensor imaging (DTI), multiple-volume proton MR spectroscopic imaging (MRSI) and functional MRI (fMRI). Metabolic imaging with PET, especially using amino acid tracers such as (18)F-fluoroethyl-L-tyrosine (FET) or (11)C-L-methionine (MET) will indicate tumour extent and response to treatment. RESULTS The new technologies comprising MR-PET hybrid systems have the advantage of providing comprehensive answers by a one-stop-job of 40-50 min. The combined approach provides data of different modalities using the same iso-centre, resulting in optimal spatial and temporal realignment. All images are acquired exactly under the same physiological conditions. CONCLUSIONS We describe the imaging protocol in detail and provide patient examples for the different imaging modalities such as FET-PET, standard structural imaging (T1-weighted, T2-weighted, T1-weighted contrast agent enhanced), DTI, MRSI and fMRI. KEY POINTS Hybrid MR-PET opens up new horizons in neuroimaging. Hybrid MR-PET allows brain tumour assessment in one stop. Hybrid MR-PET allows simultaneous acquisition of structural, functional and molecular images.
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Affiliation(s)
- Irene Neuner
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, 52428, Jülich, Germany.
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72
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Ng TSC, Bading JR, Park R, Sohi H, Procissi D, Colcher D, Conti PS, Cherry SR, Raubitschek AA, Jacobs RE. Quantitative, simultaneous PET/MRI for intratumoral imaging with an MRI-compatible PET scanner. J Nucl Med 2012; 53:1102-9. [PMID: 22661534 DOI: 10.2967/jnumed.111.099861] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Noninvasive methods are needed to explore the heterogeneous tumor microenvironment and its modulation by therapy. Hybrid PET/MRI systems are being developed for small-animal and clinical use. The advantage of these integrated systems depends on their ability to provide MR images that are spatially coincident with simultaneously acquired PET images, allowing combined functional MRI and PET studies of intratissue heterogeneity. Although much effort has been devoted to developing this new technology, the issue of quantitative and spatial fidelity of PET images from hybrid PET/MRI systems to the tissues imaged has received little attention. Here, we evaluated the ability of a first-generation, small-animal MRI-compatible PET scanner to accurately depict heterogeneous patterns of radiotracer uptake in tumors. METHODS Quantitative imaging characteristics of the MRI-compatible PET (PET/MRI) scanner were evaluated with phantoms using calibration coefficients derived from a mouse-sized linearity phantom. PET performance was compared with a commercial small-animal PET system and autoradiography in tumor-bearing mice. Pixel and structure-based similarity metrics were used to evaluate image concordance among modalities. Feasibility of simultaneous PET/MRI functional imaging of tumors was explored by following (64)Cu-labeled antibody uptake in relation to diffusion MRI using cooccurrence matrix analysis. RESULTS The PET/MRI scanner showed stable and linear response. Activity concentration recovery values (measured and true activity concentration) calculated for 4-mm-diameter rods within linearity and uniform activity rod phantoms were near unity (0.97 ± 0.06 and 1.03 ± 0.03, respectively). Intratumoral uptake patterns for both (18)F-FDG and a (64)Cu-antibody acquired using the PET/MRI scanner and small-animal PET were highly correlated with autoradiography (r > 0.99) and with each other (r = 0.97 ± 0.01). On the basis of these data, we performed a preliminary study comparing diffusion MRI and radiolabeled antibody uptake patterns over time and visualized movement of antibodies from the vascular space into the tumor mass. CONCLUSION The MRI-compatible PET scanner provided tumor images that were quantitatively accurate and spatially concordant with autoradiography and the small-animal PET examination. Cooccurrence matrix approaches enabled effective analysis of multimodal image sets. These observations confirm the ability of the current simultaneous PET/MRI system to provide accurate observations of intratumoral function and serve as a benchmark for future evaluations of hybrid instrumentation.
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Affiliation(s)
- Thomas S C Ng
- Biological Imaging Center, Beckman Institute, California Institute of Technology, Pasadena, CA, USA
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Marshall HR, Prato FS, Deans L, Théberge J, Thompson RT, Stodilka RZ. Variable Lung Density Consideration in Attenuation Correction of Whole-Body PET/MRI. J Nucl Med 2012; 53:977-84. [DOI: 10.2967/jnumed.111.098350] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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74
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Šimeček J, Schulz M, Notni J, Plutnar J, Kubíček V, Havlíčková J, Hermann P. Complexation of Metal Ions with TRAP (1,4,7-Triazacyclononane Phosphinic Acid) Ligands and 1,4,7-Triazacyclononane-1,4,7-triacetic Acid: Phosphinate-Containing Ligands as Unique Chelators for Trivalent Gallium. Inorg Chem 2011; 51:577-90. [DOI: 10.1021/ic202103v] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Jakub Šimeček
- Department of Inorganic Chemistry, Univerzita Karlova (Charles University), Hlavova 2030,
12843 Prague 2, Czech Republic
| | - Martin Schulz
- School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Johannes Notni
- Department of Inorganic Chemistry, Univerzita Karlova (Charles University), Hlavova 2030,
12843 Prague 2, Czech Republic
| | - Jan Plutnar
- Department of Inorganic Chemistry, Univerzita Karlova (Charles University), Hlavova 2030,
12843 Prague 2, Czech Republic
| | - Vojtěch Kubíček
- Department of Inorganic Chemistry, Univerzita Karlova (Charles University), Hlavova 2030,
12843 Prague 2, Czech Republic
| | - Jana Havlíčková
- Department of Inorganic Chemistry, Univerzita Karlova (Charles University), Hlavova 2030,
12843 Prague 2, Czech Republic
| | - Petr Hermann
- Department of Inorganic Chemistry, Univerzita Karlova (Charles University), Hlavova 2030,
12843 Prague 2, Czech Republic
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Heiss WD, Raab P, Lanfermann H. Multimodality assessment of brain tumors and tumor recurrence. J Nucl Med 2011; 52:1585-600. [PMID: 21840931 DOI: 10.2967/jnumed.110.084210] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Neuroimaging plays a significant role in the diagnosis of intracranial tumors, especially brain gliomas, and must consist of an assessment of location and extent of the tumor and of its biologic activity. Therefore, morphologic imaging modalities and functional, metabolic, or molecular imaging modalities should be combined for primary diagnosis and for following the course and evaluating therapeutic effects. MRI is the gold standard for providing detailed morphologic information and can supply some additional insights into metabolism (MR spectroscopy) and perfusion (perfusion-weighted imaging) but still has limitations in identifying tumor grade, invasive growth into neighboring tissue, and treatment-induced changes, as well as recurrences. These insights can be obtained by various PET modalities, including imaging of glucose metabolism, amino acid uptake, nucleoside uptake, and hypoxia. Diagnostic accuracy can benefit from coregistration of PET results and MRI, combining the high-resolution morphologic images with the biologic information. These procedures are optimized by the newly developed combination of PET and MRI modalities, permitting the simultaneous assessment of morphologic, functional, metabolic, and molecular information on the human brain.
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76
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Gade TP, Motley MW, Beattie BJ, Bhakta R, Boskey AL, Koutcher JA, Mayer-Kuckuk P. Imaging of alkaline phosphatase activity in bone tissue. PLoS One 2011; 6:e22608. [PMID: 21799916 PMCID: PMC3143164 DOI: 10.1371/journal.pone.0022608] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 06/26/2011] [Indexed: 11/18/2022] Open
Abstract
The purpose of this study was to develop a paradigm for quantitative molecular imaging of bone cell activity. We hypothesized the feasibility of non-invasive imaging of the osteoblast enzyme alkaline phosphatase (ALP) using a small imaging molecule in combination with 19Flourine magnetic resonance spectroscopic imaging (19FMRSI). 6, 8-difluoro-4-methylumbelliferyl phosphate (DiFMUP), a fluorinated ALP substrate that is activatable to a fluorescent hydrolysis product was utilized as a prototype small imaging molecule. The molecular structure of DiFMUP includes two Fluorine atoms adjacent to a phosphate group allowing it and its hydrolysis product to be distinguished using 19Fluorine magnetic resonance spectroscopy (19FMRS) and 19FMRSI. ALP-mediated hydrolysis of DiFMUP was tested on osteoblastic cells and bone tissue, using serial measurements of fluorescence activity. Extracellular activation of DiFMUP on ALP-positive mouse bone precursor cells was observed. Concurringly, DiFMUP was also activated on bone derived from rat tibia. Marked inhibition of the cell and tissue activation of DiFMUP was detected after the addition of the ALP inhibitor levamisole. 19FMRS and 19FMRSI were applied for the non-invasive measurement of DiFMUP hydrolysis. 19FMRS revealed a two-peak spectrum representing DiFMUP with an associated chemical shift for the hydrolysis product. Activation of DiFMUP by ALP yielded a characteristic pharmacokinetic profile, which was quantifiable using non-localized 19FMRS and enabled the development of a pharmacokinetic model of ALP activity. Application of 19FMRSI facilitated anatomically accurate, non-invasive imaging of ALP concentration and activity in rat bone. Thus, 19FMRSI represents a promising approach for the quantitative imaging of bone cell activity during bone formation with potential for both preclinical and clinical applications.
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Affiliation(s)
- Terence P. Gade
- Bone Cell Biology and Imaging Laboratory, Hospital for Special Surgery, New York, New York, United States of America
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Matthew W. Motley
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Bradley J. Beattie
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Roshni Bhakta
- Bone Cell Biology and Imaging Laboratory, Hospital for Special Surgery, New York, New York, United States of America
| | - Adele L. Boskey
- Mineralized Tissue Laboratory, Hospital for Special Surgery, New York, New York, United States of America
| | - Jason A. Koutcher
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Philipp Mayer-Kuckuk
- Bone Cell Biology and Imaging Laboratory, Hospital for Special Surgery, New York, New York, United States of America
- * E-mail:
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77
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Vaneycken I, D'huyvetter M, Hernot S, De Vos J, Xavier C, Devoogdt N, Caveliers V, Lahoutte T. Immuno-imaging using nanobodies. Curr Opin Biotechnol 2011; 22:877-81. [PMID: 21726996 DOI: 10.1016/j.copbio.2011.06.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 06/07/2011] [Accepted: 06/14/2011] [Indexed: 11/17/2022]
Abstract
Immuno-imaging is a developing technology that aims at studying disease in patients using imaging techniques such as positron emission tomography in combination with radiolabeled immunoglobulin derived targeting probes. Nanobodies are the smallest antigen-binding antibody-fragments and show fast and specific targeting in vivo. These probes are currently under investigation as therapeutics but preclinical studies indicate that nanobodies could also become the next generation of magic bullets for immuno-imaging. Initial data show that imaging can be performed as early as 1 hour post-injection enabling the use of short-lived radio-isotopes. These unique properties should enable patient friendly and safe imaging protocols. This review focuses on the current status of radiolabeled nanobodies as targeting probes for immuno-imaging.
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Affiliation(s)
- Ilse Vaneycken
- In vivo Cellular and Molecular Imaging Laboratory, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
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78
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Marshall HR, Stodilka RZ, Theberge J, Sabondjian E, Legros A, Deans L, Sykes JM, Thompson RT, Prato FS. A comparison of MR-based attenuation correction in PET versus SPECT. Phys Med Biol 2011; 56:4613-29. [PMID: 21725141 DOI: 10.1088/0031-9155/56/14/024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Attenuation correction (AC) is a critical step in the reconstruction of quantitatively accurate positron emission tomography (PET) and single photon emission computed tomography (SPECT) images. Several groups have proposed magnetic resonance (MR)-based AC algorithms for application in hybrid PET/MR systems. However, none of these approaches have been tested on SPECT data. Since SPECT/MR systems are under active development, it is important to ascertain whether MR-based AC algorithms validated for PET can be applied to SPECT. To investigate this issue, two imaging experiments were performed: one with an anthropomorphic chest phantom and one with two groups of canines. Both groups of canines were imaged from neck to abdomen, one with PET/CT and MR (n = 4) and the other with SPECT/CT and MR (n = 4), while the phantom was imaged with all modalities. The quality of the nuclear medicine reconstructions using MR-based attenuation maps was compared between PET and SPECT on global and local scales. In addition, the sensitivity of these reconstructions to variations in the attenuation map was ascertained. On both scales, it was found that the SPECT reconstructions were of higher fidelity than the PET reconstructions. Further, they were less sensitive to changes to the MR-based attenuation map. Thus, MR-based AC algorithms that have been designed for PET/MR can be expected to demonstrate improved performance when used for SPECT/MR.
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Affiliation(s)
- H R Marshall
- The Lawson Health Research Institute, Imaging Program, London, Ontario, Canada.
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79
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PET-MRI in the head and neck area: challenges and new directions. Eur Radiol 2011; 21:2425-6. [PMID: 21698462 PMCID: PMC3184391 DOI: 10.1007/s00330-011-2181-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 05/13/2011] [Indexed: 12/31/2022]
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80
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Pediatric oncology and the future of oncological imaging. Pediatr Radiol 2011; 41 Suppl 1:S172-85. [PMID: 21523594 DOI: 10.1007/s00247-011-2008-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 01/20/2011] [Indexed: 10/18/2022]
Abstract
The future of pediatric oncology will be influenced by changes in drug design and treatment strategy, with genomic medicine and molecular-based diagnostics and therapeutics playing increasingly important roles. The role of imaging as a means of measuring response to therapy has also evolved, with the development of new technologies and higher sensitivity means of detecting tumors. Conventional anatomical imaging techniques are being increasingly supplemented with functional techniques, including FDG-PET imaging and diffusion-weighted MR imaging. The risk-adapted treatment regimens of the past, which led to improved event-free and overall survival in many pediatric cancers, have paved the way for new response-based treatment paradigms. Response-based approaches seek to identify patients with a high likelihood of cure, treating them less aggressively, while those not responding to therapy are identified early and redirected into more aggressive therapeutic regimens. These advances will require concurrent development of imaging biomarkers as surrogates of early response to therapy. Incorporating these techniques into new response-directed treatment algorithms will be crucial as personalized medicine and molecular-targeted, tumor-specific therapies gain acceptance for the treatment of children with cancer.
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