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Roth D, Larsson E, Sundlöv A, Sjögreen Gleisner K. Characterisation of a hand-held CZT-based gamma camera for 177Lu imaging. EJNMMI Phys 2020; 7:46. [PMID: 32642884 PMCID: PMC7343677 DOI: 10.1186/s40658-020-00313-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Currently, hand-held gamma cameras are being developed for 99mTc imaging, mainly for sentinel lymph node detection. These cameras offer advantages, such as mobility and ease of access, and may be useful also for other applications such as biokinetic studies in animals or for imaging of small, superficial structures in patients. In this work, the suitability of a CZT-based hand-held camera for 177Lu imaging is investigated. The energy response of CZT-based detectors combined with the multiple photon emissions of 177Lu poses new challenges compared to 99mTc imaging, and a thorough camera characterisation is thus warranted. METHODS Three collimators (LEHR, LEHS, and MEGP) and three energy windows (55 keV, 113 keV, and 208 keV) are investigated. Characterised camera properties include the system spatial resolution, energy resolution, sensitivity, image uniformity, septal penetration, and temperature dependence. Characterisations are made starting from NEMA guidelines when applicable, with adjustments made when required. The applicability of the camera is demonstrated by imaging of a superficially located tumour in a patient undergoing [177 Lu]Lu-DOTA-TATE therapy. RESULTS Overall, the results are encouraging. Compared to a conventional gamma camera, the hand-held camera generally has a higher sensitivity for a given collimator. For source-collimator distances below 3 cm, the spatial resolution FWHM is within 6 mm for the LEHR and MEGP collimators. Before uniformity correction, the central field-of-view integral uniformity shows best results for the 113-keV window, with values obtained between 11 and 14%. The corresponding values after uniformity correction are within 3%. Effects of septal penetration are observed but are manageable with a proper combination of collimator and energy window setting. Septal penetration and collimator scatter not only affect the 208-keV window but also contribute with counts in lower windows due to energy-tailing effects. The patient study revealed non-uniform uptake patterns in a region that appeared uniform in a conventional gamma camera image. CONCLUSIONS The results show that the hand-held camera can be used for 177Lu imaging. A 113-keV energy window combined with LEHR or MEGP collimators provides the best image system characteristics.
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Affiliation(s)
- Daniel Roth
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.
| | - Erik Larsson
- Department of Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Anna Sundlöv
- Department of Medical Radiation Physics, Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Oncology and Pathology, Clinical Sciences Lund, Lund University, Lund, Sweden.,Department of Oncology, Skåne University Hospital, Lund, Sweden
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Okizaki A, Nakayama M, Nakajima K, Takahashi K. A novel iterative modified bicubic interpolation method enables high-contrast and high-resolution image generation for F-18 FDG-PET. Medicine (Baltimore) 2017; 96:e9472. [PMID: 29384938 PMCID: PMC6393029 DOI: 10.1097/md.0000000000009472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Positron emission tomography (PET) has become a useful and important technique in oncology. However, spatial resolution of PET is not high; therefore, small abnormalities can sometimes be overlooked with PET. To address this problem, we devised a novel algorithm, iterative modified bicubic interpolation method (IMBIM). IMBIM generates high resolution and -contrast image. The purpose of this study was to investigate the utility of IMBIM for clinical FDG positron emission tomography/X-ray computed tomography (PET/CT) imaging.We evaluated PET images from 1435 patients with malignant tumor and compared the contrast (uptake ratio of abnormal lesions to background) in high resolution image with the standard bicubic interpolation method (SBIM) and IMBIM. In addition to the contrast analysis, 340 out of 1435 patients were selected for visual evaluation by nuclear medicine physicians to investigate lesion detectability. Abnormal uptakes on the images were categorized as either absolutely abnormal or equivocal finding.The average of contrast with IMBIM was significantly higher than that with SBIM (P < .001). The improvements were prominent with large matrix sizes and small lesions. SBIM images showed abnormalities in 198 of 340 lesions (58.2%), while IMBIM indicated abnormalities in 312 (91.8%). There was statistically significant improvement in lesion detectability with IMBIM (P < .001).In conclusion, IMBIM generates high-resolution images with improved contrast and, therefore, may facilitate more accurate diagnoses in clinical practice.
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Takei T, Shiga T, Morimoto Y, Takeuchi W, Umegaki K, Matsuzaki K, Okamoto S, Magota K, Hara T, Fukuda S, Tamaki N. A novel PET scanner with semiconductor detectors may improve diagnostic accuracy in the metastatic survey of head and neck cancer patients. Ann Nucl Med 2012; 27:17-24. [PMID: 23124525 DOI: 10.1007/s12149-012-0654-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 09/06/2012] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Our research group developed new PET scanner with semiconductor detectors for high spatial resolution with low scatter noise. On head and neck cancer (HNC) surgery, FDG-PET may often provide false-positive findings in cervical node involvements. Accordingly, we assessed diagnostic accuracy using this new scanner in the HNC patients as compared with the conventional lutetium oxyorthosilicate (LSO) PET. METHODS We prospectively studied FDG imaging in 35 HNC patients by both semiconductor PET and LSO-PET. At 60 min after (18)F-FDG injection, two PET scans were obtained using both scanners consecutively and in random order. Two nuclear medicine specialists scored FDG abnormalities using 5 point scale system for receiver operating characteristic (ROC) curve analysis. RESULTS 63 suspected of metastatic or recurrent lesions were evaluated and correlated by the final confirmation by pathological findings or clinical courses (malignant 26/benign 37). Semiconductor PET showed sensitivity of 92.3 % (24/26), specificity of 51.4 % (19/37), and accuracy of 68.2 % (43/63), while LSO-PET showed sensitivity of 84.6 % (22/26), specificity of 16.2 %(6/37), and accuracy of 44.4 % (28/63), respectively. Especially, semiconductor PET accurately diagnosed as true negative in the 13 of 14 lesions only detected by LSO-PET. ROC analyses revealed the diagnostic superiority of semiconductor PET from location of- and area under curve particularly in the study of small (≤10 mm) lesions. CONCLUSION A new novel semiconductor PET scanner can increase diagnostic accuracy with reduction in false positive findings in the HNC patients mainly due to higher spatial resolution and lower noise than the LSO-PET. This new technology can lead to more accurate diagnosis and the more optimal therapeutic tactics in head and neck surgery.
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Affiliation(s)
- Toshiki Takei
- Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Kita-ku, Sapporo, Japan
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Washiyama K, Shiga H, Hirota K, Tsuchida A, Yamamoto J, Yagi S, Yoshizaki T, Furukawa M, Amano R, Miwa T. Biological safety of nasal thallium-201 administration: a preclinical study for olfacto-scintigraphy. JOURNAL OF RADIATION RESEARCH 2011; 52:450-455. [PMID: 21905306 DOI: 10.1269/jrr.10153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Kohshin Washiyama
- Department of Quantum Medical Technology, Graduate School of Medical Science, Kanazawa University, Ishikawa, Japan
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Xi W, Seidel J, Karkareka JW, Pohida TJ, Milenic DE, Proffitt J, Majewski S, Weisenberger AG, Green MV, Choyke PL. MONICA: a compact, portable dual gamma camera system for mouse whole-body imaging. Nucl Med Biol 2010; 37:245-53. [PMID: 20346864 PMCID: PMC2847584 DOI: 10.1016/j.nucmedbio.2009.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 12/02/2009] [Accepted: 12/03/2009] [Indexed: 11/24/2022]
Abstract
INTRODUCTION We describe a compact, portable dual-gamma camera system (named "MONICA" for MObile Nuclear Imaging CAmeras) for visualizing and analyzing the whole-body biodistribution of putative diagnostic and therapeutic single photon emitting radiotracers in animals the size of mice. METHODS Two identical, miniature pixelated NaI(Tl) gamma cameras were fabricated and installed "looking up" through the tabletop of a compact portable cart. Mice are placed directly on the tabletop for imaging. Camera imaging performance was evaluated with phantoms and field performance was evaluated in a weeklong In-111 imaging study performed in a mouse tumor xenograft model. RESULTS Tc-99m performance measurements, using a photopeak energy window of 140 keV+/-10%, yielded the following results: spatial resolution (FWHM at 1 cm), 2.2 mm; sensitivity, 149 cps (counts per seconds)/MBq (5.5 cps/microCi); energy resolution (FWHM, full width at half maximum), 10.8%; count rate linearity (count rate vs. activity), r(2)=0.99 for 0-185 MBq (0-5 mCi) in the field of view (FOV); spatial uniformity, <3% count rate variation across the FOV. Tumor and whole-body distributions of the In-111 agent were well visualized in all animals in 5-min images acquired throughout the 168-h study period. CONCLUSION Performance measurements indicate that MONICA is well suited to whole-body single photon mouse imaging. The field study suggests that inter-device communications and user-oriented interfaces included in the MONICA design facilitate use of the system in practice. We believe that MONICA may be particularly useful early in the (cancer) drug development cycle where basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors, e.g., limited imaging space, portability and, potentially, cost are important.
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Affiliation(s)
- Wenze Xi
- Science Applications International Corporation (SAIC)-Frederick, Frederick, MD
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Jurgen Seidel
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
- Contractor to SAIC-Frederick, Frederick, MD
| | - John W. Karkareka
- Signal Processing and Instrumentation Section, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD
| | - Thomas J. Pohida
- Signal Processing and Instrumentation Section, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD
| | - Diane E. Milenic
- Radioimmune & Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | | | - Stan Majewski
- Department of Radiology, West Virginia University, Morgantown, WV
| | - Andrew G. Weisenberger
- Radiation Detectors and Imaging Group, Thomas Jefferson National Accelerator Facility, Newport News, VA
| | - Michael V. Green
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
- Contractor to SAIC-Frederick, Frederick, MD
| | - Peter L. Choyke
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
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Shiga T, Morimoto Y, Kubo N, Katoh N, Katoh C, Takeuchi W, Usui R, Hirata K, Kojima S, Umegaki K, Shirato H, Tamaki N. A new PET scanner with semiconductor detectors enables better identification of intratumoral inhomogeneity. J Nucl Med 2008; 50:148-55. [PMID: 19091886 DOI: 10.2967/jnumed.108.054833] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED An autoradiography method revealed intratumoral inhomogeneity in various solid tumors. It is becoming increasingly important to estimate intratumoral inhomogeneity. However, with low spatial resolution and high scatter noise, it is difficult to detect intratumoral inhomogeneity in clinical settings. We developed a new PET system with CdTe semiconductor detectors to provide images with high spatial resolution and low scatter noise. Both phantom images and patients' images were analyzed to evaluate intratumoral inhomogeneity. METHODS This study was performed with a cold spot phantom that had 6-mm-diameter cold sphenoid defects, a dual-cylinder phantom with an adjusted concentration of 1:2, and an "H"-shaped hot phantom. These were surrounded with water. Phantom images and (18)F-FDG PET images of patients with nasopharyngeal cancer were compared with conventional bismuth germanate PET images. Profile curves for the phantoms were measured as peak-to-valley ratios to define contrast. Intratumoral inhomogeneity and tumor edge sharpness were evaluated on the images of the patients. RESULTS The contrast obtained with the semiconductor PET scanner (1.53) was 28% higher than that obtained with the conventional scanner (1.20) for the 6-mm-diameter cold sphenoid phantom. The contrast obtained with the semiconductor PET scanner (1.43) was 27% higher than that obtained with the conventional scanner (1.13) for the dual-cylinder phantom. Similarly, the 2-mm cold region between 1-mm hot rods was identified only by the new PET scanner and not by the conventional scanner. The new PET scanner identified intratumoral inhomogeneity in more detail than the conventional scanner in 6 of 10 patients. The tumor edge was sharper on the images obtained with the new PET scanner than on those obtained with the conventional scanner. CONCLUSION These phantom and clinical studies suggested that this new PET scanner has the potential for better identification of intratumoral inhomogeneity, probably because of its high spatial resolution and low scatter noise.
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Affiliation(s)
- Tohru Shiga
- Department of Nuclear Medicine, School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
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Scopinaro F, Tofani A, di Santo G, Di Pietro B, Lombardi A, Lo Russo M, Soluri A, Massari R, Trotta C, Amanti C. High-Resolution, Hand-Held Camera for Sentinel-Node Detection. Cancer Biother Radiopharm 2008; 23:43-52. [DOI: 10.1089/cbr.2007.364] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | | | - Gianpaolo di Santo
- Department of Radiological Sciences, “La Sapienza” University, Rome, Italy
| | - Barbara Di Pietro
- Department of Radiological Sciences, “La Sapienza” University, Rome, Italy
| | | | - Marzia Lo Russo
- Department of Surgery, “La Sapienza” University, Rome, Italy
| | - Alessandro Soluri
- Instituto di Ingegnaria Biomedica, Consiglio Nazionale Ricerche, Roma, Italy
| | - Roberto Massari
- Instituto di Ingegnaria Biomedica, Consiglio Nazionale Ricerche, Roma, Italy
| | - Carlo Trotta
- Instituto di Ingegnaria Biomedica, Consiglio Nazionale Ricerche, Roma, Italy
| | - Claudio Amanti
- Department of Surgery, “La Sapienza” University, Rome, Italy
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