1
|
D'Alonzo RA, Gill S, Rowshanfarzad P, Keam S, MacKinnon KM, Cook AM, Ebert MA. In vivo noninvasive preclinical tumor hypoxia imaging methods: a review. Int J Radiat Biol 2021; 97:593-631. [PMID: 33703994 DOI: 10.1080/09553002.2021.1900943] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/28/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022]
Abstract
Tumors exhibit areas of decreased oxygenation due to malformed blood vessels. This low oxygen concentration decreases the effectiveness of radiation therapy, and the resulting poor perfusion can prevent drugs from reaching areas of the tumor. Tumor hypoxia is associated with poorer prognosis and disease progression, and is therefore of interest to preclinical researchers. Although there are multiple different ways to measure tumor hypoxia and related factors, there is no standard for quantifying spatial and temporal tumor hypoxia distributions in preclinical research or in the clinic. This review compares imaging methods utilized for the purpose of assessing spatio-temporal patterns of hypoxia in the preclinical setting. Imaging methods provide varying levels of spatial and temporal resolution regarding different aspects of hypoxia, and with varying advantages and disadvantages. The choice of modality requires consideration of the specific experimental model, the nature of the required characterization and the availability of complementary modalities as well as immunohistochemistry.
Collapse
Affiliation(s)
- Rebecca A D'Alonzo
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Suki Gill
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Synat Keam
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Kelly M MacKinnon
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Alistair M Cook
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Martin A Ebert
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
- 5D Clinics, Claremont, Australia
| |
Collapse
|
2
|
Kawashiri SY, Nishino A, Shimizu T, Takatani A, Umeda M, Koga T, Iwamoto N, Ichinose K, Tamai M, Nakamura H, Origuchi T, Maeda T, Kawakami A. Fluorescence optical imaging in patients with active rheumatoid arthritis: a comparison with ultrasound and an association with biomarkers. Scand J Rheumatol 2020; 50:95-103. [PMID: 33084461 DOI: 10.1080/03009742.2020.1794028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Objectives: This study compared indocyanine green (ICG)-enhanced fluorescence optical imaging (FOI) and musculoskeletal ultrasound (MSUS), and explored the significance of the FOI findings based on the association between the FOI and MSUS findings and serum biomarkers in patients with rheumatoid arthritis (RA). The study also explored the association between the FOI findings and patients' joint destruction at the joint-area level.Method: We enrolled 50 consecutive patients with active RA from among the patients hospitalized from May 2014 to March 2016 at Nagasaki University Hospital, Japan. FOI images were acquired with the Xiralite® fluorescence imaging system and compared with the patients' clinical examination results and MSUS findings. On the same day, the patients' clinical disease activity and levels of serum biomarkers (including vascular endothelial growth factor) were obtained.Results: Although the FOI detected synovitis with high sensitivity, the frequency of positive findings and the diagnostic performance with MSUS as the reference standard for FOI differed considerably among the phases of FOI as well as among the affected joint regions. The FOI scores were positively correlated with clinical disease activity, MSUS scores, and serum biomarkers. The severity of FOI-proven synovitis was associated with the presence of MSUS-proven bone erosion.Conclusion: FOI is effective for detecting joint inflammation in RA patients, with high accuracy. The severity of the FOI score was closely associated with the joint destruction at the joint-area level. However, the significance of positive FOI findings differed depending on not only the phase of FOI but also the affected joint regions.
Collapse
Affiliation(s)
- S-Y Kawashiri
- Department of Community Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.,Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - A Nishino
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - T Shimizu
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - A Takatani
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - M Umeda
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - T Koga
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - N Iwamoto
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - K Ichinose
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - M Tamai
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - H Nakamura
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - T Origuchi
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - T Maeda
- Department of Community Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - A Kawakami
- Department of Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.,Department of Rheumatology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| |
Collapse
|
3
|
Ren W, Elmer A, Buehlmann D, Augath MA, Vats D, Ripoll J, Rudin M. Dynamic Measurement of Tumor Vascular Permeability and Perfusion using a Hybrid System for Simultaneous Magnetic Resonance and Fluorescence Imaging. Mol Imaging Biol 2016; 18:191-200. [PMID: 26381672 DOI: 10.1007/s11307-015-0884-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE Assessing tumor vascular features including permeability and perfusion is essential for diagnostic and therapeutic purposes. The aim of this study was to compare fluorescence and magnetic resonance imaging (MRI)-based vascular readouts in subcutaneously implanted tumors in mice by simultaneous dynamic measurement of tracer uptake using a hybrid fluorescence molecular tomography (FMT)/MRI system. PROCEDURE Vascular permeability was measured using a mixture of extravascular imaging agents, GdDOTA and the dye Cy5.5, and perfusion using a mixture of intravascular agents, Endorem and a fluorescent probe (Angiosense). Dynamic fluorescence reflectance imaging (dFRI) was integrated into the hybrid system for high temporal resolution. RESULTS Excellent correspondence between uptake curves of Cy5.5/GdDOTA and Endorem/Angiosense has been found with correlation coefficients R > 0.98. The two modalities revealed good agreement regarding permeability coefficients and centers-of-gravity of the imaging agent distribution. CONCLUSION The FMT/dFRI protocol presented is able to accurately map physiological processes and poses an attractive alternative to MRI for characterizing tumor neoangiogenesis.
Collapse
Affiliation(s)
- Wuwei Ren
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland
| | - Andreas Elmer
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland
| | - David Buehlmann
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland
| | - Mark-Aurel Augath
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland
| | - Divya Vats
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland
| | - Jorge Ripoll
- Department of Bioengineering, Universidad Carlos III of Madrid, 28911, Madrid, Spain.,Medical Imaging Laboratory, Hospital General Gregorio Marañón, Madrid, Spain
| | - Markus Rudin
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland. .,Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland. .,Experimental and Clinical Imaging Technologies (EXCITE), Zürich, Switzerland.
| |
Collapse
|
4
|
Monitoring Cell Death in Regorafenib-Treated Experimental Colon Carcinomas Using Annexin-Based Optical Fluorescence Imaging Validated by Perfusion MRI. PLoS One 2015; 10:e0138452. [PMID: 26393949 PMCID: PMC4578959 DOI: 10.1371/journal.pone.0138452] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/31/2015] [Indexed: 12/13/2022] Open
Abstract
Objective To investigate annexin-based optical fluorescence imaging (OI) for monitoring regorafenib-induced early cell death in experimental colon carcinomas in rats, validated by perfusion MRI and multiparametric immunohistochemistry. Materials and Methods Subcutaneous human colon carcinomas (HT-29) in athymic rats (n = 16) were imaged before and after a one-week therapy with regorafenib (n = 8) or placebo (n = 8) using annexin-based OI and perfusion MRI at 3 Tesla. Optical signal-to-noise ratio (SNR) and MRI tumor perfusion parameters (plasma flow PF, mL/100mL/min; plasma volume PV, %) were assessed. On day 7, tumors underwent immunohistochemical analysis for tumor cell apoptosis (TUNEL), proliferation (Ki-67), and microvascular density (CD31). Results Apoptosis-targeted OI demonstrated a tumor-specific probe accumulation with a significant increase of tumor SNR under therapy (mean Δ +7.78±2.95, control: -0.80±2.48, p = 0.021). MRI detected a significant reduction of tumor perfusion in the therapy group (mean ΔPF -8.17±2.32 mL/100 mL/min, control -0.11±3.36 mL/100 mL/min, p = 0.036). Immunohistochemistry showed significantly more apoptosis (TUNEL; 11392±1486 vs. 2921±334, p = 0.001), significantly less proliferation (Ki-67; 1754±184 vs. 2883±323, p = 0.012), and significantly lower microvascular density (CD31; 107±10 vs. 182±22, p = 0.006) in the therapy group. Conclusions Annexin-based OI allowed for the non-invasive monitoring of regorafenib-induced early cell death in experimental colon carcinomas, validated by perfusion MRI and multiparametric immunohistochemistry.
Collapse
|
5
|
García-Figueiras R, Padhani AR, Beer AJ, Baleato-González S, Vilanova JC, Luna A, Oleaga L, Gómez-Caamaño A, Koh DM. Imaging of Tumor Angiogenesis for Radiologists—Part 1: Biological and Technical Basis. Curr Probl Diagn Radiol 2015; 44:407-24. [DOI: 10.1067/j.cpradiol.2015.02.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 02/24/2015] [Accepted: 02/28/2015] [Indexed: 01/09/2023]
|
6
|
Penet MF, Krishnamachary B, Chen Z, Jin J, Bhujwalla ZM. Molecular imaging of the tumor microenvironment for precision medicine and theranostics. Adv Cancer Res 2015; 124:235-56. [PMID: 25287691 DOI: 10.1016/b978-0-12-411638-2.00007-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Morbidity and mortality from cancer and their associated conditions and treatments continue to extract a heavy social and economic global burden despite the transformative advances in science and technology in the twenty-first century. In fact, cancer incidence and mortality are expected to reach pandemic proportions by 2025, and costs of managing cancer will escalate to trillions of dollars. The inability to establish effective cancer treatments arises from the complexity of conditions that exist within tumors, the plasticity and adaptability of cancer cells coupled with their ability to escape immune surveillance, and the co-opted stromal cells and microenvironment that assist cancer cells in survival. Stromal cells, although destroyed together with cancer cells, have an ever-replenishing source that can assist in resurrecting tumors from any residual cancer cells that may survive treatment. The tumor microenvironment landscape is a continually changing landscape, with spatial and temporal heterogeneities that impact and influence cancer treatment outcome. Importantly, the changing landscape of the tumor microenvironment can be exploited for precision medicine and theranostics. Molecular and functional imaging can play important roles in shaping and selecting treatments to match this landscape. Our purpose in this review is to examine the roles of molecular and functional imaging, within the context of the tumor microenvironment, and the feasibility of their applications for precision medicine and theranostics in humans.
Collapse
Affiliation(s)
- Marie-France Penet
- JHU ICMIC Program, Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Balaji Krishnamachary
- JHU ICMIC Program, Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Zhihang Chen
- JHU ICMIC Program, Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jiefu Jin
- JHU ICMIC Program, Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Zaver M Bhujwalla
- JHU ICMIC Program, Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
| |
Collapse
|
7
|
Krohn M, Ohrndorf S, Werner SG, Schicke B, Burmester GR, Hamm B, Backhaus M, Hermann KGA. Near-infrared Fluorescence Optical Imaging in Early Rheumatoid Arthritis: A Comparison to Magnetic Resonance Imaging and Ultrasonography. J Rheumatol 2015; 42:1112-8. [PMID: 25934821 DOI: 10.3899/jrheum.141244] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Near-infrared fluorescence optical imaging (FOI) is a novel imaging technology in the detection and evaluation of different arthritides. FOI was validated in comparison to magnetic resonance imaging (MRI), greyscale ultrasonography (GSUS), and power Doppler ultrasonography (PDUS) in patients with early rheumatoid arthritis (RA). METHODS Hands of 31 patients with early RA were examined by FOI, MRI, and US. In each modality, synovitis of the wrist, metacarpophalangeal joints (MCP) 2-5, and proximal interphalangeal joints (PIP) 2-5 were scored on a 4-point scale (0-3). Sensitivity and specificity of FOI were analyzed in comparison to MRI and US as reference methods, differentiating between 3 phases of FOI enhancement (P1-3). Intraclass correlation coefficients (ICC) were calculated to evaluate the agreement of FOI with MRI and US. RESULTS A total of 279 joints (31 wrists, 124 MCP and 124 PIP joints) were evaluated. With MRI as the reference method, overall sensitivity/specificity of FOI was 0.81/0.00, 0.49/0.84, and 0.86/0.38 for wrist, MCP, and PIP joints, respectively. Under application of PDUS as reference, sensitivity was even higher, while specificity turned out to be low, except for MCP joints (0.88/0.15, 0.81/0.76, and 1.00/0.27, respectively). P2 appears to be the most sensitive FOI phase, while P1 showed the highest specificity. The best agreement of FOI was shown for PDUS, especially with regard to MCP and PIP joints (ICC of 0.57 and 0.53, respectively), while correlation with MRI was slightly lower. CONCLUSION FOI remains an interesting diagnostic tool for patients with early RA, although this study revealed limitations concerning the detection of synovitis. Further research is needed to evaluate its full diagnostic potential in rheumatic diseases.
Collapse
Affiliation(s)
- Michaela Krohn
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Sarah Ohrndorf
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Stephanie G Werner
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Bernd Schicke
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Gerd-Rüdiger Burmester
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Bernd Hamm
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Marina Backhaus
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital
| | - Kay-Geert A Hermann
- From the Department of Radiology, and the Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin; RHIO - Rheumatology, Immunology, Osteology Center, Düsseldorf; Berlin Cancer Center (Tumorzentrum Berlin), Berlin, Germany.M. Krohn, MD, Department of Radiology, Charité University Hospital; S. Ohrndorf, MD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; S.G. Werner, MD, RHIO; B. Schicke, Berlin Cancer Center (Tumorzentrum Berlin); G.R. Burmester, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; B. Hamm, MD, PhD, Department of Radiology, Charité University Hospital; M. Backhaus, MD, PhD, Department of Rheumatology and Clinical Immunology, Charité University Hospital; K.G. Hermann, MD, PhD, Department of Radiology, Charité University Hospital.
| |
Collapse
|
8
|
Werner SG, Langer HE, Schott P, Bahner M, Schwenke C, Lind-Albrecht G, Spiecker F, Kurtz B, Burmester GR, Backhaus M. Indocyanine Green-Enhanced Fluorescence Optical Imaging in Patients With Early and Very Early Arthritis: A Comparative Study With Magnetic Resonance Imaging. ACTA ACUST UNITED AC 2013; 65:3036-44. [DOI: 10.1002/art.38175] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 08/22/2013] [Indexed: 01/18/2023]
Affiliation(s)
- Stephanie G. Werner
- Charité University Medicine Berlin; Berlin Germany
- RHIO Center Dusseldorf and RHIO Research Institute; Dusseldorf Germany
| | | | - Peter Schott
- Evangelisches Krankenhaus Dusseldorf; Dusseldorf Germany
| | | | | | | | | | - Bernward Kurtz
- Evangelisches Krankenhaus Dusseldorf; Dusseldorf Germany
| | | | | |
Collapse
|
9
|
Grazul-Bilska AT, Borowicz PP, Reynolds LP, Redmer DA. Vascular perfusion with fluorescent labeled lectin to study ovarian functions. Acta Histochem 2013; 115:893-8. [PMID: 23622682 DOI: 10.1016/j.acthis.2013.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 03/11/2013] [Accepted: 03/12/2013] [Indexed: 12/23/2022]
Abstract
The aim of this study was to optimize a method to visualize tissue vascularity by perfusing the local vascular bed with a fluorescently labeled lectin, combined with immunofluorescent labeling of selected vascular/tissue markers. Ovaries with the pedicle were obtained from adult non-pregnant ewes. Immediately after collection, the ovarian artery was perfused with phosphate buffered saline (PBS) to remove blood cells, followed by perfusion with PBS containing fluorescently labeled Griffonia (Bandeiraea) simplicifolia (BS1) lectin. Then, half of ovary was fixed in formalin and another half in Carnoy's fixative. BS1 was detected in blood vessels in ovaries fixed in formalin, but not in Carnoy's fixative. Formalin fixed tissue was used for immunofluorescence staining of two markers of tissue function and/or structure, Ki67 and smooth muscle cell actin (SMCA). Ki67 was detected in granulosa and theca cells, luteal and stromal tissue, and a portion of Ki67 staining was co-localized with blood vessels. SMCA was detected in pericytes within the capillary system, in blood vessels in all ovarian compartments, and in the stroma. Thus, blood vessel perfusion with fluorescently labeled lectin combined with immunohistochemistry, microscopy, and imaging techniques provide an excellent tool to study angiogenesis, vascular architecture, and organ structures and function in physiological and pathological conditions.
Collapse
Affiliation(s)
- Anna T Grazul-Bilska
- Department of Animal Sciences, North Dakota State University, Fargo, ND 58102, USA.
| | | | | | | |
Collapse
|
10
|
Ehling J, Lammers T, Kiessling F. Non-invasive imaging for studying anti-angiogenic therapy effects. Thromb Haemost 2013; 109:375-90. [PMID: 23407722 DOI: 10.1160/th12-10-0721] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 12/28/2012] [Indexed: 12/14/2022]
Abstract
Noninvasive imaging plays an emerging role in preclinical and clinical cancer research and has high potential to improve clinical translation of new drugs. This article summarises and discusses tools and methods to image tumour angiogenesis and monitor anti-angiogenic therapy effects. In this context, micro-computed tomography (µCT) is recommended to visualise and quantify the micro-architecture of functional tumour vessels. Contrast-enhanced ultrasound (US) and magnetic resonance imaging (MRI) are favourable tools to assess functional vascular parameters, such as perfusion and relative blood volume. These functional parameters have been shown to indicate anti-angiogenic therapy response at an early stage, before changes in tumour size appear. For tumour characterisation, the imaging of the molecular characteristics of tumour blood vessels, such as receptor expression, might have an even higher diagnostic potential and has been shown to be highly suitable for therapy monitoring as well. In this context, US using targeted microbubbles is currently evaluated in clinical trials as an important tool for the molecular characterisation of the angiogenic endothelium. Other modalities, being preferably used for molecular imaging of vessels and their surrounding stroma, are photoacoustic imaging (PAI), near-infrared fluorescence optical imaging (OI), MRI, positron emission tomography (PET) and single photon emission computed tomography (SPECT). The latter two are particularly useful if very high sensitivity is needed, and/or if the molecular target is difficult to access. Carefully considering the pros and cons of different imaging modalities in a multimodal imaging setup enables a comprehensive longitudinal assessment of the (micro)morphology, function and molecular regulation of tumour vessels.
Collapse
Affiliation(s)
- Josef Ehling
- Department of Experimental Molecular Imaging, Medical Faculty and Helmholtz Institute for Biomedical Engineering, Pauwelsstraße 30, 52074 Aachen, Germany
| | | | | |
Collapse
|
11
|
Korotcov AV, Ye Y, Chen Y, Zhang F, Huang S, Lin S, Sridhar R, Achilefu S, Wang PC. Glucosamine-linked near-infrared fluorescent probes for imaging of solid tumor xenografts. Mol Imaging Biol 2012; 14:443-51. [PMID: 21971932 DOI: 10.1007/s11307-011-0520-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Near-infrared fluorescence (NIRF) imaging is an attractive technique for studying diseases at the molecular level in vivo. Glucose transporters are often used as targets for in vivo imaging of tumors. The efficiency of a tumor-seeking fluorescent probe can be enhanced by attaching one or more glucosamine (GlcN) moieties. This study was designed to evaluate the use of previously developed GlcN-linked NIRF probes for in vitro and in vivo optical imaging of cancer. PROCEDURES Cellular uptake of the probes (1 μM) was investigated in monolayer cultures of luciferase-expressing PC3 (PC3-luc) cells. The prostate tumors were established as subcutaneous xenografts using PC3-luc cells in nude mice. The biodistributions and tumor-targeting specificities of cypate (cyp), cypate-D: -(+)-glucosamine (cyp-GlcN), and D: -(+)-gluosamine-cypate-D: -(+)-gluosamine (cyp-2GlcN) were studied. The tumor, muscle, and major organs were collected for ex vivo optical imaging. RESULTS The tumor cell uptake of the probe containing two glucosamine residues, cyp-2GlcN, was significantly higher than the uptake of both the probe with one glucosamine residue, cyp-GlcN, and the probe without glucosamine, cyp only. Similarly, in in vivo experiments, cyp-2GlcN demonstrated higher maximum fluorescence intensity and longer residence lifetime in tumors than cyp-GlcN or cyp. The ex vivo biodistribution analysis revealed that tumor uptake of cyp-2GlcN and cyp-GlcN was four- and twofold higher than that of cyp at 24 h post-injection, respectively. CONCLUSION Both cyp-GlcN and cyp-2GlcN NIRF probes exhibited good tumor-targeting properties in prostate cancer cell cultures and live mice. The cyp-2GlcN probe showed the highest uptake with good retention characteristics in vivo. The uptake of cyp-2GlcN and cyp-GlcN is likely mediated by glucosamine-recognizing transporters. The uptake mechanism is being explored further for developing cypate-glucosamine-based probes for in vivo imaging.
Collapse
Affiliation(s)
- Alexandru V Korotcov
- Molecular Imaging Laboratory, Department of Radiology, Howard University, Washington, DC, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Parashurama N, O’Sullivan TD, De La Zerda A, El Kalassi P, Cho S, Liu H, Teed R, Levy H, Rosenberg J, Cheng Z, Levi O, Harris JS, Gambhir SS. Continuous sensing of tumor-targeted molecular probes with a vertical cavity surface emitting laser-based biosensor. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:117004. [PMID: 23123976 PMCID: PMC3595658 DOI: 10.1117/1.jbo.17.11.117004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/24/2012] [Accepted: 09/25/2012] [Indexed: 05/29/2023]
Abstract
Molecular optical imaging is a widespread technique for interrogating molecular events in living subjects. However, current approaches preclude long-term, continuous measurements in awake, mobile subjects, a strategy crucial in several medical conditions. Consequently, we designed a novel, lightweight miniature biosensor for in vivo continuous optical sensing. The biosensor contains an enclosed vertical-cavity surface-emitting semiconductor laser and an adjacent pair of near-infrared optically filtered detectors. We employed two sensors (dual sensing) to simultaneously interrogate normal and diseased tumor sites. Having established the sensors are precise with phantom and in vivo studies, we performed dual, continuous sensing in tumor (human glioblastoma cells) bearing mice using the targeted molecular probe cRGD-Cy5.5, which targets αVβ3 cell surface integrins in both tumor neovasculature and tumor. The sensors capture the dynamic time-activity curve of the targeted molecular probe. The average tumor to background ratio after signal calibration for cRGD-Cy5.5 injection is approximately 2.43±0.95 at 1 h and 3.64±1.38 at 2 h (N=5 mice), consistent with data obtained with a cooled charge coupled device camera. We conclude that our novel, portable, precise biosensor can be used to evaluate both kinetics and steady state levels of molecular probes in various disease applications.
Collapse
Affiliation(s)
- Natesh Parashurama
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
| | - Thomas D. O’Sullivan
- Stanford University, Department of Electrical Engineering, 475 Via Ortega, Stanford, California 94305
| | - Adam De La Zerda
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
- Stanford University, Department of Electrical Engineering, 475 Via Ortega, Stanford, California 94305
| | - Pascale El Kalassi
- Stanford University, Department of Electrical Engineering, 475 Via Ortega, Stanford, California 94305
| | - Seongjae Cho
- Stanford University, Department of Electrical Engineering, 475 Via Ortega, Stanford, California 94305
| | - Hongguang Liu
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
| | - Robert Teed
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
- Stanford University, Canary Center for Early Detection of Cancer, 1501 South California Avenue, Palo Alto, California 94304
| | - Hart Levy
- University of Toronto, Institute of Biomaterials and Biomedical Engineering, Rosebrugh Building, 164 College Street, Room 407, Toronto, Ontario M5S 3G9, Canada
- University of Toronto, The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, 10 King's College Road, Toronto, Ontario M5S 3G4, Canada
| | - Jarrett Rosenberg
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
| | - Zhen Cheng
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
| | - Ofer Levi
- University of Toronto, Institute of Biomaterials and Biomedical Engineering, Rosebrugh Building, 164 College Street, Room 407, Toronto, Ontario M5S 3G9, Canada
- University of Toronto, The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, 10 King's College Road, Toronto, Ontario M5S 3G4, Canada
| | - James S. Harris
- Stanford University, Department of Electrical Engineering, 475 Via Ortega, Stanford, California 94305
- Stanford University, Department of Materials Science and Engineering, 496 Lomita Mall, Stanford, California 94305
| | - Sanjiv S. Gambhir
- Stanford University, Molecular Imaging Program at Stanford (MIPS), Division of Nuclear Medicine, Department of Radiology, James H. Clark Center, 318 Campus Drive, E153, Stanford, California 94305
- Stanford University, Department of Bioengineering, 318 Campus Drive, Stanford, California 94305
- Stanford University, Department of Materials Science and Engineering, 496 Lomita Mall, Stanford, California 94305
- Stanford University, Canary Center for Early Detection of Cancer, 1501 South California Avenue, Palo Alto, California 94304
| |
Collapse
|
13
|
Waschkau B, Faust A, Schäfers M, Bremer C. Performance of a new fluorescence-labeled MMP inhibitor to image tumor MMP activityin vivoin comparison to an MMP-activatable probe. CONTRAST MEDIA & MOLECULAR IMAGING 2012; 8:1-11. [DOI: 10.1002/cmmi.1486] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Bianca Waschkau
- Department of Clinical Radiology, Albert-Schweitzer-Campus 1 building A16; University Hospital Muenster; D-48149 Muenster Germany
| | - Andreas Faust
- European Institute of Molecular Imaging, Mendelstr. 11; University Muenster; D-48149 Muenster Germany
| | - Michael Schäfers
- European Institute of Molecular Imaging, Mendelstr. 11; University Muenster; D-48149 Muenster Germany
| | - Christoph Bremer
- Department of Clinical Radiology, Albert-Schweitzer-Campus 1 building A16; University Hospital Muenster; D-48149 Muenster Germany
- Interdisciplinary Center of Clinical Research; University of Muenster; D-48149 Muenster Germany
| |
Collapse
|
14
|
Werner SG, Langer HE, Ohrndorf S, Bahner M, Schott P, Schwenke C, Schirner M, Bastian H, Lind-Albrecht G, Kurtz B, Burmester GR, Backhaus M. Inflammation assessment in patients with arthritis using a novel in vivo fluorescence optical imaging technology. Ann Rheum Dis 2012; 71:504-10. [PMID: 22388997 PMCID: PMC3298665 DOI: 10.1136/annrheumdis-2010-148288] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Indocyanine green (ICG)-enhanced fluorescence optical imaging (FOI) is an established technology for imaging of inflammation in animal models. In experimental models of arthritis, FOI findings corresponded to histologically proven synovitis. This is the first comparative study of FOI with other imaging modalities in humans with arthritis. METHODS 252 FOI examinations (Xiralite system, mivenion GmbH, Berlin, Germany; ICG bolus of 0.1 mg/kg/body weight, sequence of 360 images, one image per second) were compared with clinical examination (CE), ultrasonography (US) and MRI of patients with arthritis of the hands. RESULTS In an FOI sequence, three phases could be distinguished (P1-P3). With MRI as reference, FOI had a sensitivity of 76% and a specificity of 54%, while the specificity of phase 1 was 94%. FOI had agreement rates up to 88% versus CE, 64% versus greyscale US, 88% versus power Doppler US and 83% versus MRI, depending on the compared phase and parameter. FOI showed a higher rate of positive results compared to CE, US and MRI. In individual patients, FOI correlated significantly (p<0.05) with disease activity (Disease Activity Score 28, r=0.41), US (r=0.40) and RAMRIS (Rheumatoid Arthritis MRI Score) (r=0.56). FOI was normal in 97.8% of joints of controls. CONCLUSION ICG-enhanced FOI is a new technology offering sensitive imaging detection of inflammatory changes in subjects with arthritis. FOI was more sensitive than CE and had good agreement with CE, US in power Doppler mode and MRI, while showing more positive results than these. An adequate interpretation of an FOI sequence requires a separate evaluation of all phases. For the detection of synovitis and tenosynovitis, FOI appears to be as informative as 1.5 T MRI and US.
Collapse
|
15
|
Flexman ML, Vlachos F, Kim HK, Sirsi SR, Huang J, Hernandez SL, Johung TB, Gander JW, Reichstein AR, Lampl BS, Wang A, Borden MA, Yamashiro DJ, Kandel JJ, Hielscher AH. Monitoring early tumor response to drug therapy with diffuse optical tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:016014. [PMID: 22352664 PMCID: PMC3380816 DOI: 10.1117/1.jbo.17.1.016014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/25/2011] [Accepted: 11/30/2011] [Indexed: 05/18/2023]
Abstract
Although anti-angiogenic agents have shown promise as cancer therapeutics, their efficacy varies between tumor types and individual patients. Providing patient-specific metrics through rapid noninvasive imaging can help tailor drug treatment by optimizing dosages, timing of drug cycles, and duration of therapy-thereby reducing toxicity and cost and improving patient outcome. Diffuse optical tomography (DOT) is a noninvasive three-dimensional imaging modality that has been shown to capture physiologic changes in tumors through visualization of oxygenated, deoxygenated, and total hemoglobin concentrations, using non-ionizing radiation with near-infrared light. We employed a small animal model to ascertain if tumor response to bevacizumab (BV), an anti-angiogenic agent that targets vascular endothelial growth factor (VEGF), could be detected at early time points using DOT. We detected a significant decrease in total hemoglobin levels as soon as one day after BV treatment in responder xenograft tumors (SK-NEP-1), but not in SK-NEP-1 control tumors or in non-responder control or BV-treated NGP tumors. These results are confirmed by magnetic resonance imaging T2 relaxometry and lectin perfusion studies. Noninvasive DOT imaging may allow for earlier and more effective control of anti-angiogenic therapy.
Collapse
Affiliation(s)
- Molly L. Flexman
- Columbia University, New York, Department of Biomedical Engineering, New York, New York 10027
- Address all correspondence to: Andreas H. Hielscher, Columbia University, Department of Biomedical Engineering, 351 Engineering Terrace, 500 W. 120th Ave, New York, New York 10027. Tel: 212-854-5080; E-mail:
| | - Fotios Vlachos
- Columbia University, New York, Department of Biomedical Engineering, New York, New York 10027
| | - Hyun Keol Kim
- Columbia University, New York, Department of Biomedical Engineering, New York, New York 10027
| | - Shashank R. Sirsi
- Columbia University, New York, Department of Chemical Engineering, New York, New York 10027
- University of Colorado, Boulder, Department of Mechanical Engineering, Boulder, Colorado 80309
| | - Jianzhong Huang
- Columbia University, New York, Department of Surgery, New York, New York 10032
| | - Sonia L. Hernandez
- Columbia University, New York, Department of Pediatrics and Pathology, New York, New York 10032
| | - Tessa B. Johung
- Columbia University, New York, Department of Surgery, New York, New York 10032
| | - Jeffrey W. Gander
- Columbia University, New York, Department of Surgery, New York, New York 10032
| | - Ari R. Reichstein
- Columbia University, New York, Department of Surgery, New York, New York 10032
| | - Brooke S. Lampl
- Columbia University, New York, Department of Radiology, New York, New York 10032
| | - Antai Wang
- Columbia University, New York, Department of Biostatistics, Mailman School of Public Health, New York, New York 10032
| | - Mark A. Borden
- Columbia University, New York, Department of Chemical Engineering, New York, New York 10027
- University of Colorado, Boulder, Department of Mechanical Engineering, Boulder, Colorado 80309
| | - Darrell J. Yamashiro
- Columbia University, New York, Department of Surgery, New York, New York 10032
- Columbia University, New York, Department of Pediatrics and Pathology, New York, New York 10032
| | - Jessica J. Kandel
- Columbia University, New York, Department of Surgery, New York, New York 10032
| | - Andreas H. Hielscher
- Columbia University, New York, Department of Biomedical Engineering, New York, New York 10027
- Columbia University, New York, Department of Radiology, New York, New York 10032
- Columbia University, New York, Department of Electrical Engineering, New York, New York 10027
| |
Collapse
|
16
|
Confocal laser endomicroscopy and narrow-band imaging-aided endoscopy for in vivo imaging of colitis and colon cancer in mice. Nat Protoc 2011; 6:1471-81. [PMID: 21886109 DOI: 10.1038/nprot.2011.377] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
New endoscopic techniques such as narrow-band imaging (NBI) and confocal laser endomicroscopy (CLE) have improved the in vivo diagnosis of human gastrointestinal diseases in the colon. Whereas NBI may facilitate the identification of neoplastic lesions, CLE permits real-time histology of the inflamed or neoplastic colonic mucosa through the use of fluorescent dyes. These techniques have been recently adopted for use during ongoing endoscopy in mice. This protocol, which can be completed in 2 h, provides a detailed description of NBI and CLE in the mouse colon. In contrast to other techniques, this approach does not require laparotomy, and it allows direct CLE analysis of lesions identified by NBI. Mice exposed to models of colitis or colorectal cancer are anesthetized and examined with a miniaturized NBI endoscope, which provides an increased contrast of the vasculature. Upon identification of suspicious areas by NBI and the administration of fluorescent dyes, a confocal laser probe can be directed to the area of interest through the endoscope and confocal images can be obtained. Through the use of various fluorescent dyes, different aspects of the mucosa can be assessed. In addition, fluorescence-labeled antibodies can be used for molecular imaging of mice in vivo. Mouse NBI endoscopy and CLE represent reliable and fast high-quality techniques for the endoscopic characterization and molecular imaging of the mucosa in colitis and colon cancer.
Collapse
|
17
|
Beer AJ, Chen X. Imaging of angiogenesis: from morphology to molecules and from bench to bedside. Eur J Nucl Med Mol Imaging 2010; 37 Suppl 1:S1-3. [PMID: 20640419 PMCID: PMC3617496 DOI: 10.1007/s00259-010-1501-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ambros J Beer
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
| | | |
Collapse
|