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Jin Y, Meng LJ. Exploration of Coincidence Detection of Cascade Photons to Enhance Preclinical Multi-Radionuclide SPECT Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2024; 43:1766-1781. [PMID: 38163304 DOI: 10.1109/tmi.2023.3348756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
We proposed a technique of coincidence detection of cascade photons (CDCP) to enhance preclinical SPECT imaging of therapeutic radionuclides emitting cascade photons, such as Lu-177, Ac-225, Ra-223, and In-111. We have carried out experimental studies to evaluate the proposed CDCP-SPECT imaging of low-activity radionuclides using a prototype coincidence detection system constructed with large-volume cadmium zinc telluride (CZT) imaging spectrometers and a pinhole collimator. With In-111 in experimental studies, the CDCP technique allows us to improve the signal-to-contamination in the projection (Projection-SCR) by ~53 times and reduce ~98% of the normalized contamination. Compared to traditional scatter correction, which achieves a Projection-SCR of 1.00, our CDCP method boosts it to 15.91, showing enhanced efficacy in reducing down-scattered contamination, especially at lower activities. The reconstructed images of a line source demonstrated the dramatic enhancement of the image quality with CDCP-SPECT compared to conventional and triple-energy-window-corrected SPECT data acquisition. We also introduced artificial energy blurring and Monte Carlo simulation to quantify the impact of detector performance, especially its energy resolution and timing resolution, on the enhancement through the CDCP technique. We have further demonstrated the benefits of the CDCP technique with simulation studies, which shows the potential of improving the signal-to-contamination ratio by 300 times with Ac-225, which emits cascade photons with a decay constant of ~0.1 ns. These results have demonstrated the potential of CDCP-enhanced SPECT for imaging a super-low level of therapeutic radionuclides in small animals.
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Massalha S, Kennedy J, Hussein E, Mahida B, Keidar Z. Cardiovascular Imaging in Women. Semin Nucl Med 2024; 54:191-205. [PMID: 38395672 DOI: 10.1053/j.semnuclmed.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 01/28/2024] [Indexed: 02/25/2024]
Abstract
Multimodality cardiovascular imaging is a cornerstone diagnostic tool in the diagnosis, risk stratification, and management of cardiovascular diseases, whether those involving the coronary tree, myocardial, or pericardial diseases in general and particularly in women. This manuscript aims to shed some light and summarize the very features of cardiovascular disease in women, explore their unique characteristics and discuss the role of cardiovascular imaging in ischemic heart disease and cardiomyopathies. The role of four imaging modalities will be discussed including nuclear medicine, echocardiography, noninvasive coronary angiography, and cardiac magnetic resonance.
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Affiliation(s)
- Samia Massalha
- Department of Cardiology, Rambam Health Care Campus, Haifa. Israel; Department of Nuclear Medicine, Rambam Health Care Campus, Haifa. Israel.
| | - John Kennedy
- Department of Cardiology, Rambam Health Care Campus, Haifa. Israel; Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Essam Hussein
- Department of Nuclear Medicine, Rambam Health Care Campus, Haifa. Israel
| | - Besma Mahida
- Nuclear Medicine BICHAT Hospital Assistance Publique Hôpitaux de Paris, Paris. France; LVTS, Inserm U1148, Équipe 4 (Imagerie Cardio-Vasculaire), Paris, France
| | - Zohar Keidar
- Department of Cardiology, Rambam Health Care Campus, Haifa. Israel; Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
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Comparison of reprojected bone SPECT/CT and planar bone scintigraphy for the detection of bone metastases in breast and prostate cancer. Nucl Med Commun 2022; 43:510-517. [PMID: 35081092 DOI: 10.1097/mnm.0000000000001536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of this study was to compare reprojected bone SPECT/CT (RBS) against planar bone scintigraphy (BS) in the detection of bone metastases in breast and prostate cancer patients. METHODS Twenty-six breast and 105 prostate cancer patients with high risk for bone metastases underwent 99mTc-HMDP BS and whole-body SPECT/CT, 1.5-T whole-body diffusion-weighted MRI and 18F-NaF or 18F-PSMA-1007 PET/CT within two prospective clinical trials (NCT01339780 and NCT03537391). Consensus reading of all imaging modalities and follow-up data were used to define the reference standard diagnosis. The SPECT/CT data were reprojected into anterior and posterior views to produce RBS images. Both BS and RBS images were independently double read by two pairs of experienced nuclear medicine physicians. The findings were validated against the reference standard diagnosis and compared between BS and RBS on the patient, region and lesion levels. RESULTS All metastatic patients detected by BS were also detected by RBS. In addition, three metastatic patients were missed by BS but detected by RBS. The average patient-level sensitivity of two readers for metastases was 75% for BS and 87% for RBS, and the corresponding specificity was 79% for BS and 39% for RBS. The average region-level sensitivity of two readers was 64% for BS and 69% for RBS, and the corresponding specificity was 96% for BS and 87% for RBS. CONCLUSION Whole-body bone SPECT/CT can be reprojected into more familiar anterior and posterior planar images with excellent sensitivity for bone metastases, making additional acquisition of planar BS unnecessary.
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Zhou J, Leja AG, Salvatori M, Latta DD, Di Fulvio A. Application of Monte Carlo Algorithms to Cardiac Imaging Reconstruction. Curr Pharm Des 2021; 27:1960-1972. [PMID: 33371829 DOI: 10.2174/1381612826999201228215225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/07/2020] [Indexed: 11/22/2022]
Abstract
Monte Carlo algorithms have a growing impact on nuclear medicine reconstruction processes. One of the main limitations of myocardial perfusion imaging (MPI) is the effective mitigation of the scattering component, which is particularly challenging in Single Photon Emission Computed Tomography (SPECT). In SPECT, no timing information can be retrieved to locate the primary source photons. Monte Carlo methods allow an event-by-event simulation of the scattering kinematics, which can be incorporated into a model of the imaging system response. This approach was adopted in the late Nineties by several authors, and recently took advantage of the increased computational power made available by high-performance CPUs and GPUs. These recent developments enable a fast image reconstruction with improved image quality, compared to deterministic approaches. Deterministic approaches are based on energy-windowing of the detector response, and on the cumulative estimate and subtraction of the scattering component. In this paper, we review the main strategies and algorithms to correct the scattering effect in SPECT and focus on Monte Carlo developments, which nowadays allow the threedimensional reconstruction of SPECT cardiac images in a few seconds.
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Affiliation(s)
- J Zhou
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
| | - A G Leja
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
| | - M Salvatori
- Fondazione Toscana G. Monasterio, Massa, MS 54100, Italy
| | - D Della Latta
- Fondazione Toscana G. Monasterio, Massa, MS 54100, Italy
| | - A Di Fulvio
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, United States
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Lotter K, Diemling M, Sohlberg A, Wiedner H, Haug A, Maringer FJ. Comparing calculated and experimental activity and dose values obtained from image-based quantification of 90Y SPECT/CT Data. Z Med Phys 2021; 31:378-387. [PMID: 33966943 DOI: 10.1016/j.zemedi.2021.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 01/13/2021] [Accepted: 03/29/2021] [Indexed: 11/19/2022]
Abstract
PURPOSE Selective internal radiation therapy (SIRT) is a treatment for various kinds of liver tumours by injecting 90Y bearing microspheres into the liver vessels. To perform meaningful post-treatment dosimetry, quantitative imaging is performed. METHODS This work uses a Monte-Carlo based reconstruction software with scatter and attenuation correction and collimator modelling that allows the quantification of 90Y bremsstrahlung SPECT/CT data. A dataset comprising 17 patients and measurements on a Jaszczak phantom, a NEMA IEC Body phantom and an anthropomorphic liver phantom are analysed and activities and dose values are acquired. These measured values are compared with applied activities and pre-treatment calculations, allowing to assess the quality of the SPECT reconstruction. A detailed uncertainty budget is presented, including uncertainties of the dose calibrator, the count rate, non-included interactions and other factors. RESULTS The applied method is validated by finding measurements repeatable within the given uncertainty, and it is shown the influence of various parameters on the reconstruction process is negligible. Furthermore, activities and doses measured in the phantoms show good agreement with calculated values, if they are corrected for partial volume effects. CONCLUSIONS The strict observation of metrological requirements and the creation of an uncertainty budget increase the reliability and traceability of this novel approach to 90Y dosimetry. It gives an example of successful voxel-based dosimetry based on quantitative 90Y SPECT/CT image data.
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Affiliation(s)
- Konrad Lotter
- Technische Universität Wien - Technical University of Vienna, Karlsplatz 13, 1040 Wien, Austria.
| | - Markus Diemling
- HERMES Medical Solutions, Skeppsbron 44, 111 30 Stockholm, Sweden
| | - Antti Sohlberg
- HERMES Medical Solutions, Skeppsbron 44, 111 30 Stockholm, Sweden
| | - Hannah Wiedner
- Bundesamt für Eich- und Vermessungswesen, Arltgasse 35, 1160 Wien, Austria
| | - Alexander Haug
- Division of Nuclear Medicine, Medical University of Vienna, Spitalgasse 23, 1090 Wien, Austria
| | - Franz Josef Maringer
- Technische Universität Wien - Technical University of Vienna, Karlsplatz 13, 1040 Wien, Austria; Bundesamt für Eich- und Vermessungswesen, Arltgasse 35, 1160 Wien, Austria
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Kangasmaa TS, Constable C, Sohlberg AO. Quantitative bone SPECT/CT reconstruction utilizing anatomical information. EJNMMI Phys 2021; 8:2. [PMID: 33409675 PMCID: PMC7788147 DOI: 10.1186/s40658-020-00348-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/16/2020] [Indexed: 11/24/2022] Open
Abstract
Background Bone SPECT/CT has been shown to offer superior sensitivity and specificity compared to conventional whole-body planar scanning. Furthermore, bone SPECT/CT allows quantitative imaging, which is challenging with planar methods. In order to gain better quantitative accuracy, Bayesian reconstruction algorithms, including both image derived and anatomically guided priors, have been utilized in reconstruction in PET/CT scanning, but they have not been widely used in SPECT/CT studies. Therefore, the aim of this work was to evaluate the performance of CT-guided reconstruction in quantitative bone SPECT. Methods Three Bayesian reconstruction methods were evaluated against the conventional ordered subsets expectation maximization (OSEM) reconstruction method. One of the studied Bayesian methods was the relative difference prior (RDP), which has recently gained popularity in PET reconstruction. The other two methods, anatomically guided smoothing prior (AMAP-S) and anatomically guided relative difference prior (AMAP-R), utilized anatomical information from the CT scan. The reconstruction methods were evaluated in terms of quantitative accuracy with artificial lesions inserted in clinical patient studies and with 20 real clinical patients. Maximum and mean standardized uptake values (SUVs) of the lesions were defined. Results The analyses showed that all studied Bayesian methods performed better than OSEM and the anatomical priors also outperformed RDP. The average relative error in mean SUV for the artificial lesion study for OSEM, RDP, AMAP-S, and AMAP-R was − 53%, − 35%, − 15%, and − 10%, when the CT study had matching lesions. In the patient study, the RDP method gave 16 ± 9% higher maximum SUV values than OSEM, while AMAP-S and AMAP-R offered increases of 36 ± 8% and 36 ± 9%, respectively. Mean SUV increased for RDP, AMAP-S, and AMAP-R by 18 ± 9%, 26 ± 5%, and 33 ± 5% when compared to OSEM. Conclusions The Bayesian methods with anatomical prior, especially the relative difference prior-based method (AMAP-R), outperformed OSEM and reconstruction without anatomical prior in terms of quantitative accuracy.
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Affiliation(s)
- Tuija S Kangasmaa
- Department of Clinical Physiology and Nuclear Medicine, Vaasa Central Hospital, Hietalahdenkatu 2-4, 65130, Vaasa, Finland.
| | - Chris Constable
- HERMES Medical Solutions, Strandbergsgatan 16, 11251, Stockholm, Sweden
| | - Antti O Sohlberg
- HERMES Medical Solutions, Strandbergsgatan 16, 11251, Stockholm, Sweden.,Laboratory of Clinical Physiology and Nuclear Medicine, Päijät-Häme Central Hospital, Keskussairaalankatu 7, 15850, Lahti, Finland
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Kangasmaa T, Hippeläinen E, Constable C, Turunen S, Sohlberg A. Quantitative Monte Carlo-based brain dopamine transporter SPECT imaging. Ann Nucl Med 2020; 35:17-23. [PMID: 32978713 DOI: 10.1007/s12149-020-01532-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/16/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Brain dopamine transporter imaging with I-123-labeled radioligands is technically demanding due to the small size of the imaging target relative to the spatial resolution of most SPECT systems. In addition, I-123 has high-energy peaks which can penetrate or scatter in the collimator and be detected in the imaging energy window. The aim of this study was to implement Monte Carlo (MC)-based full collimator-detector response (CDR) compensation algorithm for I-123 into a third-party commercial SPECT reconstruction software package and to evaluate its effect on the quantitative accuracy of dopaminergic-image analysis compared to a method where only the geometric component of the CDR is compensated. METHODS In this work, we utilized a full Monte Carlo collimator-detector model and incorporated it into an iterative SPECT reconstruction algorithm. The full Monte Carlo model reconstruction was compared to standard reconstruction using an anthropomorphic striatal phantom filled with different I-123 striatal/cortex uptake ratios and with clinical I-123 Ioflupane DaTScan studies. RESULTS Reconstruction with the full model yielded higher (13-25%) striatal uptake ratios than the conventional reconstruction, but the uptake ratios were still much lower than the true ratios due to partial volume effect. Visually, images reconstructed with the full Monte Carlo model had better contrast and resolution than the conventional images, with both phantom and patient studies. CONCLUSIONS Reconstruction with full Monte Carlo collimator-detector model yields higher quantitative accuracy than conventional reconstruction. Additional work to reduce the partial volume effect related errors would improve the accuracy further.
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Affiliation(s)
- Tuija Kangasmaa
- Department of Clinical Physiology and Nuclear Medicine, Vaasa Central Hospital, Hietalahdenkatu 2-4, 65130, Vaasa, Finland.
| | - Eero Hippeläinen
- Clinical Physiology and Nuclear Medicine, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 4, 00029, Helsinki, Finland
| | - Chris Constable
- HERMES Medical Solutions, Strandbergsgatan 16, 11251, Stockholm, Sweden
| | - Sampsa Turunen
- Clinical Physiology and Nuclear Medicine, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 4, 00029, Helsinki, Finland
| | - Antti Sohlberg
- HERMES Medical Solutions, Strandbergsgatan 16, 11251, Stockholm, Sweden.,Laboratory of Clinical Physiology and Nuclear Medicine, Päijät-Häme Central Hospital, Keskussairaalankatu 7, 15850, Lahti, Finland
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Brady SL, Shulkin BL. Analysis of quantitative [I-123] mIBG SPECT/CT in a phantom and in patients with neuroblastoma. EJNMMI Phys 2019; 6:31. [PMID: 31889238 PMCID: PMC6937351 DOI: 10.1186/s40658-019-0267-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/02/2019] [Indexed: 11/13/2022] Open
Abstract
Purpose To determine the accuracy of quantitative SPECT, intersystem and interpatient standardized uptake value (SUV) calculation consistency for a manufacturer-independent quantitative SPECT/CT reconstruction algorithm, and the range of SUVs of normal and neoplastic tissue. Methods A NEMA body phantom with 6 spheres (ranging 10–37 mm) was filled with a known activity-to-volume ratio and used to determine the contrast recovery coefficient (CRC) for each visible sphere, and the measured SUV accuracy of those spheres and background water solution. One hundred eleven 123I-metaiodobenzylguanidine ([I-123] mIBG) SPECT/CT examinations from 43 patients were reconstructed using SUV SPECT® (HERMES Medical Solutions Inc.); 42 examinations were acquired using a GE Infinia Hawkeye 4 SPECT/CT, and 69 were acquired on a Siemens Symbia Intevo SPECT/CT. Inter scanner SUV analysis of 9 regions of normal [I-123] mIBG tissue uptake was conducted. Intrapatient mean SUV variability was calculated by measuring normal liver uptake within patients scanned on both cameras. The intensity of uptake by neoplastic tissue in the images was quantified using maximum SUV and, if present, compared over time. Results The phantom results of the visible spheres and background resulted in accuracy calculations better than 5–10% with CRC correction. Interscanner SUV variability showed no statistical difference (average p value 0.559; range 0.066–1.0) among the 9 normal tissues analyzed. Intrapatient liver mean SUV varied ≤ 16% as calculated for 28 patients (87 examinations) studied on both scanners. In one patient, a thoracic tumor evaluated over 10 time points (18 months) underwent a 74% (3.1/12.0) reduction in maximum SUV with treatment. Conclusion The results demonstrate quantitative accuracy to better than 10%, and both consistent SUV calculation between 2 different SPECT/CT scanners for 9 tissues, and low intrapatient measurement variability for quantitative SPECT/CT analysis in a pediatric population with neuroblastoma. Quantitative SPECT/CT offers the opportunity for objective analysis of tumor response using [I-123] mIBG by normalizing the uptake to injected dose and patient weight, as is done for PET.
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Affiliation(s)
- Samuel L Brady
- Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Barry L Shulkin
- Department of Diagnostic Imaging MS 220, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105-3678, USA.
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Evaluation of quantitative 123I and 131I SPECT with Monte Carlo-based down-scatter compensation. Nucl Med Commun 2018; 39:1097-1102. [PMID: 30222722 DOI: 10.1097/mnm.0000000000000920] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Quantitative I and I single-photon emission computed tomography (SPECT) is hampered by down-scatter from the high-energy peaks. This paper presents a down-scatter compensation method, where down-scatter generated in the patient and gamma camera collimator and detector is modelled using Monte Carlo simulation in the ordered subsets expectation maximization SPECT reconstruction algorithm. MATERIALS AND METHODS The new down-scatter compensation method was compared with conventional triple energy window (TEW) scatter compensation and Gaussian convolution-based forced detection Monte Carlo methods. The comparison was made with the NEMA-IEC phantom using six spherical inserts (diameters from 10 to 37 mm) and a lung compartment. The phantom was filled with I and I solutions to known sphere-to-background concentration ratios. Spherical volumes of interest with the same diameter as the inserts were drawn on the images, and recovery coefficients for the spheres were calculated in addition to lung-to-background ratio. RESULTS The new down-scatter compensation method provided higher recovery coefficients than the TEW scatter compensation or Gaussian convolution-based forced detection Monte Carlo algorithm for both isotopes. Background activity concentration could be accurately estimated with the new down-scatter compensation method and with the TEW scatter compensation, whereas activity concentration of the spheres was severely underestimated even with the new method. CONCLUSION Down-scatter compensation with Monte Carlo-simulation effectively reduces down-scatter effects in I and I SPECT imaging.
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