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Gibson PG, Urroz Guerrero PD, Poon C, Rutherford N, Brooker B, Smith A, Grainge C, Wark PAB, McDonald VM. Ventilation Heterogeneity Is a Treatable Trait in Severe Asthma. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2024; 12:929-935.e4. [PMID: 38151119 DOI: 10.1016/j.jaip.2023.12.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/30/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023]
Abstract
BACKGROUND Ventilation heterogeneity (VH) is a feature of asthma and indicates small airway disease. Nuclear imaging methods assess VH, which can facilitate clinical diagnosis and further our understanding of disease aetiology. OBJECTIVE We sought to assess VH in severe eosinophilic asthma (SEA) using ventilation/perfusion single-photon emission computed tomography (V/P SPECT), and to assess its use as an objective test of the effect of biologic treatment for ventilation defects in SEA. METHODS Adults (≥18 y) with severe asthma were recruited to participate in a cross-sectional observational study. Participants underwent a clinical assessment and V/P SPECT CT using Technegas as the ventilation agent. Measures were repeated for a nested before-after treatment study in people with SEA commencing biologics. RESULTS A total of 62 participants with severe asthma were recruited. From this, 38 participants with SEA were included in the before-after study. The VH was associated with clinical variables such as lung function impairment and significantly improved after monoclonal antibody treatment in the severe asthma group. The changes in VH correlated with change in post bronchodilator forced expiratory volume in 1 second (FEV1) %predicted (r = -0.503; P = .001) and post bronchodilator FEV1/FVC (forced vital capacity) (r = -0.415; P = .01). CONCLUSIONS The VH is clinically significant, measurable, and treatable, which establishes VH as a treatable trait in severe asthma.
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Affiliation(s)
- Peter G Gibson
- Centre of Excellence in Treatable Traits, College of Health, Medicine and Wellbeing, University of Newcastle, New Lambton Heights, New South Wales, Australia; Department of Respiratory and Sleep Medicine, John Hunter Hospital, New Lambton Heights, New South Wales, Australia.
| | - Paola D Urroz Guerrero
- Centre of Excellence in Treatable Traits, College of Health, Medicine and Wellbeing, University of Newcastle, New Lambton Heights, New South Wales, Australia; School of Nursing and Midwifery, University of Newcastle, Callaghan, New South Wales, Australia
| | - Christine Poon
- Cyclomedica Australia Pty Ltd, Kingsgrove, New South Wales, Australia
| | - Natalie Rutherford
- Department of Nuclear Medicine, John Hunter Hospital, New Lambton Heights, New South Wales, Australia
| | - Bree Brooker
- Department of Nuclear Medicine, John Hunter Hospital, New Lambton Heights, New South Wales, Australia
| | - Amber Smith
- Centre of Excellence in Treatable Traits, College of Health, Medicine and Wellbeing, University of Newcastle, New Lambton Heights, New South Wales, Australia; School of Nursing and Midwifery, University of Newcastle, Callaghan, New South Wales, Australia
| | - Christopher Grainge
- Department of Respiratory and Sleep Medicine, John Hunter Hospital, New Lambton Heights, New South Wales, Australia
| | - Peter A B Wark
- Department of Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia; Department of Respiratory Medicine, Alfred Health, Melbourne, VIC, Australia
| | - Vanessa M McDonald
- Centre of Excellence in Treatable Traits, College of Health, Medicine and Wellbeing, University of Newcastle, New Lambton Heights, New South Wales, Australia; Department of Respiratory and Sleep Medicine, John Hunter Hospital, New Lambton Heights, New South Wales, Australia; School of Nursing and Midwifery, University of Newcastle, Callaghan, New South Wales, Australia
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Astley JR, Biancardi AM, Marshall H, Hughes PJC, Collier GJ, Hatton MQ, Wild JM, Tahir BA. A hybrid model- and deep learning-based framework for functional lung image synthesis from multi-inflation CT and hyperpolarized gas MRI. Med Phys 2023; 50:5657-5670. [PMID: 36932692 PMCID: PMC10946819 DOI: 10.1002/mp.16369] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 02/25/2023] [Accepted: 03/04/2023] [Indexed: 03/19/2023] Open
Abstract
BACKGROUND Hyperpolarized gas MRI is a functional lung imaging modality capable of visualizing regional lung ventilation with exceptional detail within a single breath. However, this modality requires specialized equipment and exogenous contrast, which limits widespread clinical adoption. CT ventilation imaging employs various metrics to model regional ventilation from non-contrast CT scans acquired at multiple inflation levels and has demonstrated moderate spatial correlation with hyperpolarized gas MRI. Recently, deep learning (DL)-based methods, utilizing convolutional neural networks (CNNs), have been leveraged for image synthesis applications. Hybrid approaches integrating computational modeling and data-driven methods have been utilized in cases where datasets are limited with the added benefit of maintaining physiological plausibility. PURPOSE To develop and evaluate a multi-channel DL-based method that combines modeling and data-driven approaches to synthesize hyperpolarized gas MRI lung ventilation scans from multi-inflation, non-contrast CT and quantitatively compare these synthetic ventilation scans to conventional CT ventilation modeling. METHODS In this study, we propose a hybrid DL configuration that integrates model- and data-driven methods to synthesize hyperpolarized gas MRI lung ventilation scans from a combination of non-contrast, multi-inflation CT and CT ventilation modeling. We used a diverse dataset comprising paired inspiratory and expiratory CT and helium-3 hyperpolarized gas MRI for 47 participants with a range of pulmonary pathologies. We performed six-fold cross-validation on the dataset and evaluated the spatial correlation between the synthetic ventilation and real hyperpolarized gas MRI scans; the proposed hybrid framework was compared to conventional CT ventilation modeling and other non-hybrid DL configurations. Synthetic ventilation scans were evaluated using voxel-wise evaluation metrics such as Spearman's correlation and mean square error (MSE), in addition to clinical biomarkers of lung function such as the ventilated lung percentage (VLP). Furthermore, regional localization of ventilated and defect lung regions was assessed via the Dice similarity coefficient (DSC). RESULTS We showed that the proposed hybrid framework is capable of accurately replicating ventilation defects seen in the real hyperpolarized gas MRI scans, achieving a voxel-wise Spearman's correlation of 0.57 ± 0.17 and an MSE of 0.017 ± 0.01. The hybrid framework significantly outperformed CT ventilation modeling alone and all other DL configurations using Spearman's correlation. The proposed framework was capable of generating clinically relevant metrics such as the VLP without manual intervention, resulting in a Bland-Altman bias of 3.04%, significantly outperforming CT ventilation modeling. Relative to CT ventilation modeling, the hybrid framework yielded significantly more accurate delineations of ventilated and defect lung regions, achieving a DSC of 0.95 and 0.48 for ventilated and defect regions, respectively. CONCLUSION The ability to generate realistic synthetic ventilation scans from CT has implications for several clinical applications, including functional lung avoidance radiotherapy and treatment response mapping. CT is an integral part of almost every clinical lung imaging workflow and hence is readily available for most patients; therefore, synthetic ventilation from non-contrast CT can provide patients with wider access to ventilation imaging worldwide.
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Affiliation(s)
- Joshua R Astley
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Alberto M Biancardi
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Helen Marshall
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Paul J C Hughes
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Guilhem J Collier
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Matthew Q Hatton
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
| | - Jim M Wild
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, The University of Sheffield, Sheffield, UK
| | - Bilal A Tahir
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, The University of Sheffield, Sheffield, UK
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3
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Astley JR, Biancardi AM, Marshall H, Smith LJ, Hughes PJC, Collier GJ, Saunders LC, Norquay G, Tofan MM, Hatton MQ, Hughes R, Wild JM, Tahir BA. PhysVENeT: a physiologically-informed deep learning-based framework for the synthesis of 3D hyperpolarized gas MRI ventilation. Sci Rep 2023; 13:11273. [PMID: 37438406 DOI: 10.1038/s41598-023-38105-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 07/03/2023] [Indexed: 07/14/2023] Open
Abstract
Functional lung imaging modalities such as hyperpolarized gas MRI ventilation enable visualization and quantification of regional lung ventilation; however, these techniques require specialized equipment and exogenous contrast, limiting clinical adoption. Physiologically-informed techniques to map proton (1H)-MRI ventilation have been proposed. These approaches have demonstrated moderate correlation with hyperpolarized gas MRI. Recently, deep learning (DL) has been used for image synthesis applications, including functional lung image synthesis. Here, we propose a 3D multi-channel convolutional neural network that employs physiologically-informed ventilation mapping and multi-inflation structural 1H-MRI to synthesize 3D ventilation surrogates (PhysVENeT). The dataset comprised paired inspiratory and expiratory 1H-MRI scans and corresponding hyperpolarized gas MRI scans from 170 participants with various pulmonary pathologies. We performed fivefold cross-validation on 150 of these participants and used 20 participants with a previously unseen pathology (post COVID-19) for external validation. Synthetic ventilation surrogates were evaluated using voxel-wise correlation and structural similarity metrics; the proposed PhysVENeT framework significantly outperformed conventional 1H-MRI ventilation mapping and other DL approaches which did not utilize structural imaging and ventilation mapping. PhysVENeT can accurately reflect ventilation defects and exhibits minimal overfitting on external validation data compared to DL approaches that do not integrate physiologically-informed mapping.
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Affiliation(s)
- Joshua R Astley
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Alberto M Biancardi
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Helen Marshall
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Laurie J Smith
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Paul J C Hughes
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Guilhem J Collier
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Laura C Saunders
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Graham Norquay
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Malina-Maria Tofan
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
| | - Matthew Q Hatton
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK
| | - Rod Hughes
- Early Development Respiratory Medicine, AstraZeneca, Cambridge, UK
| | - Jim M Wild
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK
- Insigneo Institute for in Silico Medicine, The University of Sheffield, Sheffield, UK
| | - Bilal A Tahir
- Department of Oncology and Metabolism, The University of Sheffield, Sheffield, UK.
- POLARIS, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, UK.
- Insigneo Institute for in Silico Medicine, The University of Sheffield, Sheffield, UK.
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Assessment of Regional Lung Ventilation with Positron Emission Tomography Using the Radiofluorinated Gas [ 18F]SF 6: Application to an Animal Model of Impaired Ventilation. Mol Imaging Biol 2023; 25:413-422. [PMID: 36167904 DOI: 10.1007/s11307-022-01773-7] [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: 08/03/2022] [Revised: 09/07/2022] [Accepted: 09/09/2022] [Indexed: 10/14/2022]
Abstract
PURPOSE Clinical ventilation studies are primarily performed with computerized tomography (CT) and more often with single-photon emission Computerized tomography (SPECT) using radiolabelled aerosols, both presenting certain limitations. Here, we investigate the use of the radiofluorinated gas [18F]SF6 as a positron emission tomography (PET) ventilation marker in an animal model of impaired lung ventilation. PROCEDURES Sprague-Dawley rats (n = 15) were randomly assigned to spontaneous ventilation (sham group), endotracheal administration of phosphate-buffered saline (PBS group), or endotracheal administration of lipopolysaccharide (LPS group). PET-[18F]SF6 images (10-min acquisition) were acquired at t = 48 h after LPS or PBS administration under mechanical ventilation. CT images were acquired after each PET session. Volumes of interest were manually delineated in the lungs on CT images, and voxel-by-voxel analysis was carried out on PET images to obtain the corresponding histograms. After the imaging sessions, lungs were harvested to conduct histological analysis. RESULTS Ventilation studies in sham animals showed uniform distribution of [18F]SF6 and fast elimination of the radioactivity after discontinuation of the administration. For PBS- and LPS-treated rats, ventilation defects were observed on PET images in some animals, identified as regions with low presence of the radiolabelled gas. Hypoventilated areas co-localized with regions with higher x-ray attenuation than healthy lungs on the CT images, suggesting the presence of oedema and, in some cases, atelectasis. Histograms obtained from PET images showed quasi-Gaussian distributions for control animals, while PBS- and LPS-treated animals demonstrated the presence of hypoventilated voxels. Deviation of the histograms from Gaussian distribution correlated with histological score was obtained by ex vivo histological analysis. CONCLUSIONS [18F]SF6 is an appropriate marker of regional lung ventilation and may find application in the early diagnose of acute lung disease.
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Khatib I, Young PM. Technegas, A Universal Technique for Lung Imaging in Nuclear Medicine: Technology, Physicochemical Properties, and Clinical Applications. Pharmaceutics 2023; 15:pharmaceutics15041108. [PMID: 37111594 PMCID: PMC10144982 DOI: 10.3390/pharmaceutics15041108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
Technegas was developed in Australia as an imaging radioaerosol in the late 1980s and is now commercialized by Cyclomedica, Pty Ltd. for diagnosing pulmonary embolism (PE). Technegas is produced by heating technetium-99m in a carbon crucible for a few seconds at high temperatures (2750 °C) to generate technetium–carbon nanoparticles with a gas-like behaviour. The submicron particulates formed allow easy diffusion to the lung periphery when inhaled. Technegas has been used for diagnosis in over 4.4 m patients across 60 countries and now offers exciting opportunities in areas outside of PE, including asthma and chronic obstructive pulmonary disease (COPD). The Technegas generation process and the physicochemical attributes of the aerosol have been studied over the past 30 years in parallel with the advancement in different analytical methodologies. Thus, it is now well established that the Technegas aerosol has a radioactivity aerodynamic diameter of <500 nm and is composed of agglomerated nanoparticles. With a plethora of literature studying different aspects of Technegas, this review focuses on a historical evaluation of the different methodologies’ findings over the years that provides insight into a scientific consensus of this technology. Also, we briefly discuss recent clinical innovations using Technegas and a brief history of Technegas patents.
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Affiliation(s)
- Isra Khatib
- Ab Initio Pharma Pty Ltd., 67-73 Missenden Road, Camperdown, NSW 2050, Australia;
| | - Paul M. Young
- Ab Initio Pharma Pty Ltd., 67-73 Missenden Road, Camperdown, NSW 2050, Australia;
- Woolcock Institute of Medical Research, 431 Glebe Point Road, Glebe, NSW 2037, Australia
- Macquarie Business School, Macquarie University, NSW 2109, Australia
- Correspondence:
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Tanguay J, Basharat F. Xenon-enhanced dual-energy tomosynthesis for functional imaging of respiratory disease-Concept and phantom study. Med Phys 2023; 50:719-736. [PMID: 36419344 DOI: 10.1002/mp.16101] [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: 04/09/2022] [Revised: 10/21/2022] [Accepted: 10/23/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Xenon-enhanced dual-energy (DE) computed tomography (CT) and hyperpolarized noble-gas magnetic resonance imaging (MRI) provide maps of lung ventilation that can be used to detect chronic obstructive pulmonary disease (COPD) early in its development and predict respiratory exacerbations. However, xenon-enhanced DE-CT requires high radiation doses and hyper-polarized noble-gas MRI is expensive and only available at a handful of institutions globally. PURPOSE To present xenon-enhanced dual-energy tomosynthesis (XeDET) for low-dose, low-cost functional imaging of respiratory disease in an experimental phantom study. METHODS We propose using digital tomosynthesis to produce Xe-enhanced low-energy (LE) and high-energy (HE) coronal images. DE subtraction of the LE and HE images is used to suppress soft tissues. We used an imaging phantom to investigate image quality in terms of the area under the reciever operating characteristic curve (AUC) for the Non-PreWhitening model observer with an Eye filter and internal noise (NPWEi). The phantom simulated anatomic clutter due to lung parenchyma and attenuation due to soft tissue and lung tissue. Aluminum slats were used to simulate rib structures. A stepwedge consisting of an acrylic casing with sealed cylindrical air-filled cavities was used to simulate ventilation defects with step thicknesses of 0.5, 1, and 2 cm and cylindrical radii of 0.5, 0.75, and 1 cm. The phantom was ventilated with Xe and projection data were acquired using a flat-panel detector, a tube-voltage combination of 60/140 kV with 1.2 mm of copper filtration on the HE spectrum and an angular range of ± 15 ∘ $\pm 15^{\circ}$ in 1° increments. The AUC of a NPWEi observer that has access only to a single coronal slice was calculated from measurements of the three-dimensional noise power spectrum and signal template. The AUC was calculated as a function of ventilation defect thickness and radius for total patient entrance air kermas ranging from 1.42 to 2.84 mGy with and without rib-simulating Al slats. For the AUC analysis, the observer internal noise level was obtained from an ad hoc calibration to a high-dose data set. RESULTS XeDET was able to suppress parenchyma-simulating clutter in coronal images enabling visualization of the simulated ventilation defects, but the limited angle acquisition resulted in residual clutter due to out-of-plane bone-mimmicking structures. The signal power of the defects increased linearly with defect radius and showed a ten-fold to fifteen-fold increase in signal power when the defect thickness increased from 0.5 to 2 cm. These trends agreed with theoretical predictions. Along the depth dimension, the power of the defects decreased exponentially with distance from the center of the defects with full-width half maxima that varied from 1.85 to 2.85 cm depending on the defect thickness and radius. The AUCs of the 1-cm-radius defect that was 2 cm in thickness ranged from good (0.8-0.9) to excellent (0.9-1.0) over the range of air kermas considered. CONCLUSIONS Xenon-enhanced DE tomosynthesis has the potential to enable functional imaging of respiratory disease and should be further investigated as a low-cost alternative to MRI-based approaches and a low-dose alternative to CT-based approaches.
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Affiliation(s)
- Jesse Tanguay
- Department of Physics, Toronto Metropoliton University (formerly Ryerson University), Toronto, ON, Canada
| | - Fateen Basharat
- Department of Physics, Toronto Metropoliton University (formerly Ryerson University), Toronto, ON, Canada
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Le Roux PY, Schafer WM, Blanc-Beguin F, Tulchinsky M. Ventilation Scintigraphy With Radiolabeled Carbon Nanoparticulate Aerosol (Technegas): State-of-the-Art Review and Diagnostic Applications to Pulmonary Embolism During COVID-19 Pandemic. Clin Nucl Med 2023; 48:8-17. [PMID: 36288606 PMCID: PMC9762616 DOI: 10.1097/rlu.0000000000004426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/01/2022] [Indexed: 12/14/2022]
Abstract
ABSTRACT Invented and first approved for clinical use in Australia 36 years ago, Technegas is the technology that enabled ventilation scintigraphy with 99m Tc-labeled carbon nanoparticles ( 99m Tc-CNP). The US Food and Drug Administration (FDA) has considered this technology for more than 30 years but only now is getting close to approving it. Meanwhile, more than 4.4 million patients benefited from this technology in 64 countries worldwide. The primary application of 99m Tc-CNP ventilation imaging is the diagnostic evaluation for suspicion of pulmonary embolism using ventilation-perfusion quotient (V/Q) imaging. Because of 99m Tc-CNP's long pulmonary residence, tomographic imaging emerged as the preferred V/Q methodology. The FDA-approved ventilation imaging agents are primarily suitable for planar imaging, which is less sensitive. After the FDA approval of Technegas, the US practice will likely shift to tomographic V/Q. The 99m Tc-CNP use is of particular interest in the COVID-19 pandemic because it offers an option of a dry radioaerosol that takes approximately only 3 to 5 tidal breaths, allowing the shortest exposure to and contact with possibly infected patients. Indeed, countries where 99m Tc-CNP was approved for clinical use continued using it throughout the COVID-19 pandemic without known negative viral transmission consequences. Conversely, the ventilation imaging was halted in most US facilities from the beginning of the pandemic. This review is intended to familiarize the US clinical nuclear medicine community with the basic science of 99m Tc-CNP ventilation imaging and its clinical applications, including common artifacts and interpretation criteria for tomographic V/Q imaging for pulmonary embolism.
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Affiliation(s)
- Pierre-Yves Le Roux
- From the INSERM (National Institute of Health and Medical Research) and Department of Nuclear Medicine, University Hospital of Brest, CHRU Brest, UMR 1304, GETBO, Brest, France
| | - Wolfgang M. Schafer
- Nuclear Medicine Clinic, Maria Hilf Hospital Inc, Academic Teaching Hospital of RWTH Aachen University, Moenchengladbach, Germany
| | - Frédérique Blanc-Beguin
- From the INSERM (National Institute of Health and Medical Research) and Department of Nuclear Medicine, University Hospital of Brest, CHRU Brest, UMR 1304, GETBO, Brest, France
| | - Mark Tulchinsky
- Section of Nuclear Medicine, Department of Radiology, Penn State University Hospital, Hershey, PA
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Basharat F, Tanguay J. Experimental feasibility of xenon-enhanced dual-energy radiography for imaging of lung function. Phys Med Biol 2022; 67. [PMID: 36395522 DOI: 10.1088/1361-6560/aca3f8] [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: 08/04/2022] [Accepted: 11/17/2022] [Indexed: 11/19/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. We experimentally investigated the feasibility of two-dimensional xenon-enhanced dual-energy (XeDE) radiography for imaging of lung function. We optimized image quality under quantum-noise-limited conditions using a chest phantom consisting of a rectangular chamber representing the thoracic volume and PMMA slabs simulating x-ray attenuation by soft tissue. A sealed, air-filled cavity with thin PMMA walls was positioned inside the chamber to simulate a 2 cm thick ventilation defect. The chamber was ventilated with xenon and dual-energy imaging was performed using a diagnostic x-ray tube and a flat-panel detector. The contrast-to-noise ratio of ventilation defects normalized by patient x-ray exposure maximized at a kV-pair of approximately 60/140-kV and when approximately one third of the total exposure was allocated to the HE image. We used the optimized technique to image a second phantom that contained lung-parenchyma-mimicking PMMA clutter, rib-mimicking aluminum slats and an insert that simulated ventilation defects with thicknesses ranging from 0.5 cm to 2 cm and diameters ranging from 1 cm to 2 cm. From the resulting images we computed the area under the receiver operating characteristic curve (AUC) of the non-prewhitening model observer with an eye filter and internal noise. For a xenon concentration of 75%, good AUCs (i.e. 0.8-0.9) to excellent AUCs (i.e. >0.9) were obtained when the defect diameter is greater than 1.3 cm and defect thickness is 1 cm. When the xenon concentration was reduced to 50%, the AUC was ∼0.9 for defects 1.2 cm in diameter and ∼1.5 cm in thickness. Two-dimensional XeDE radiography may therefore enable detection of functional abnormalities associated with early-stage COPD, for which xenon ventilation defects can occupy up to 20% of the lung volume, and should be further developed as a low-cost alternative to MRI-based approaches and a low-dose alternative to CT-based approaches.
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Affiliation(s)
- Fateen Basharat
- Department of Physics, Toronto Metropolitan University, Toronto, ON, Canada
| | - Jesse Tanguay
- Department of Physics, Toronto Metropolitan University, Toronto, ON, Canada
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Schroeder JA, Cao Q, Sotirchos VS, Gillman JA, Anderson T, Pilati S, Dubroff JG, Farwell M, Kozlov A, Korhonen K, Pryma DA, Pantel AR. Perfusion-only imaging in pregnant women: A comparative reader study with implications for practice patterns. Medicine (Baltimore) 2022; 101:e30800. [PMID: 36181041 PMCID: PMC9524957 DOI: 10.1097/md.0000000000030800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
This study seeks to understand the value of ventilation imaging in pregnant patients imaged for suspected pulmonary embolism (PE). Ventilation-perfusion (VQ) scans in this high-risk population were compared to ventilation-only scans. We hypothesize that in this relatively healthy population, the exclusion of ventilation scans will not impact the rate of scans interpreted as positive. This retrospective blinded comparative reader study on collated VQ scans performed on pregnant patients in the course of routine clinical care in a > 5 year period (03/2012 to 07/2017). Each set of VQ and perfusion only (Q) studies were reviewed by 8 readers (4 nuclear radiology fellows and 4 nuclear medicine faculty) in random order; the Q scans simply omitted the ventilation images. Readers recorded each study as PE, no PE, or non-diagnostic (prospective investigative study of acute PE diagnosis classifications). Logistic mixed effects models were used to test the association between scan type (VQ vs Q). 203 pairs of studies in 197 patients were included (6 patients had 2 scans). Subjects ranged from 14 to 45 years of age, with a median 28 years. A significant association between scan type and positive/negative classification. Q-scans received more positive classifications than VQ-scans (median of 7.6% vs 6.7%). No association was seen between scan type and positive/indeterminate classification, nor between scan type and negative/indeterminate classification. The exclusion of ventilation images in VQ-scans was associated with a higher rate of positive studies, but this difference was small (<1%). Given the overwhelmingly normal percentage of Q-exams (>90% in our study), and the benefits of omitting ventilation imaging, perfusion-only imaging should be considered a reasonable option for imaging the pregnant patient to exclude PE.
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Affiliation(s)
- Jennifer A. Schroeder
- Department of Radiology, Nuclear Medicine, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, USA
- * Correspondence: Jennifer A. Schroeder, Department of Radiology, Nuclear Medicine, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, USA (e-mail: )
| | - Quy Cao
- Department of Biostatistics, Epidemiology, & Informatics, University of Pennsylvania, Philadelphia, PA, USA
| | - Vlasios S. Sotirchos
- Interventional Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jennifer A. Gillman
- Department of Radiology, Mid-Atlantic Permanente Medical Group, Rockville, MD, USA
| | - Thomas Anderson
- Department of Radiology, University of New Mexico, Albuquerque, NM, USA
| | - Stamatoula Pilati
- Department of Radiology and Nuclear Medicine, Cook County Health, Chicago, IL, USA
| | - Jacob G. Dubroff
- Department of Radiology, Nuclear Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Farwell
- Department of Radiology, Nuclear Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrew Kozlov
- Radiology Associates of Florida & the University of South Florida, Morsani College of Medicine, Philadelphia, PA, USA
| | | | - Daniel A. Pryma
- Department of Radiology, Nuclear Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Austin R. Pantel
- Department of Radiology, Nuclear Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Abstract
One of the major effects of the COVID-19 pandemic within nuclear medicine was to halt performance of lung ventilation studies, due to concern regarding spread of contaminated secretions into the ambient air. A number of variant protocols for performing lung scintigraphy emerged in the medical literature which minimized or eliminated the ventilation component, due to the persistent need to provide this critical diagnostic service without compromising the safety of staff and patients. We have summarized and reviewed these protocols, many of which are based on concepts developed earlier in the history of lung scintigraphy. It is possible that some of these interim remedies may gain traction and earn a more permanent place in the ongoing practice of nuclear medicine.
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Affiliation(s)
- Lionel S. Zuckier
- Address reprint requests to Lionel S. Zuckier, Division of Nuclear Medicine, Department of Radiology, Montefiore Medical Center, Bronx, NY 10467
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Bajc M, Lindqvist A. Pulmonary Embolism: Ventilation/Perfusion Scintigraphy as a Proper Tool in Diagnosing Pulmonary Embolism and Frequent Pulmonary Comorbidities. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00023-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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12
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Maincent C, Perrin C, Chironi G, Baqué-Juston M, Berthier F, Paulmier B, Hugonnet F, Dittlot C, Farhad RL, Renvoise J, Serrano B, Nataf V, Mocquot F, Keita-Perse O, Claessens YE, Faraggi M. Microvascular injuries, secondary edema, and inconsistencies in lung vascularization between affected and nonaffected pulmonary segments of non-critically ill hospitalized COVID-19 patients presenting with clinical deterioration. Ther Adv Respir Dis 2022; 16:17534666221096040. [PMID: 35485327 PMCID: PMC9058452 DOI: 10.1177/17534666221096040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Purpose: We aimed to better understand the pathophysiology of SARS-CoV-2 pneumonia in non-critically ill hospitalized patients secondarily presenting with clinical deterioration and increase in oxygen requirement without any identified worsening factors. Methods: We consecutively enrolled patients without clinical or biological evidence for superinfection, without left ventricular dysfunction and for whom a pulmonary embolism was discarded by computed tomography (CT) pulmonary angiography. We investigated lung ventilation and perfusion (LVP) by LVP scintigraphy, and, 24 h later, left and right ventricular function by Tc-99m-labeled albumin-gated blood-pool scintigraphy with late (60 mn) tomographic albumin images on the lungs to evaluate lung albumin retention that could indicate microvascular injuries with secondary edema. Results: We included 20 patients with confirmed SARS-CoV-2 pneumonia. All had CT evidence of organizing pneumonia and normal left ventricular ejection fraction. No patient demonstrated preserved ventilation with perfusion defect (mismatch), which may discard a distal lung thrombosis. Patterns of ventilation and perfusion were heterogeneous in seven patients (35%) with healthy lung segments presenting a relative paradoxical hypoperfusion and hypoventilation compared with segments with organizing pneumonia presenting a relative enhancement in perfusion and preserved ventilation. Lung albumin retention in area of organizing pneumonia was observed in 12 patients (60%), indicating microvascular injuries, increase in vessel permeability, and secondary edema. Conclusion: In hospitalized non-critically ill patients without evidence of superinfection, pulmonary embolism, or cardiac dysfunction, various types of damage may contribute to clinical deterioration including microvascular injuries and secondary edema, inconsistencies in lung segments vascularization suggesting a dysregulation of the balance in perfusion between segments affected by COVID-19 and others. Summary Statement Microvascular injuries and dysregulation of the balance in perfusion between segments affected by COVID-19 and others are present in non-critically ill patients without other known aggravating factors. Key Results In non-critically ill patients without evidence of superinfection, pulmonary embolism, macroscopic distal thrombosis or cardiac dysfunction, various types of damage may contribute to clinical deterioration including 1/ microvascular injuries and secondary edema, 2/ inconsistencies in lung segments vascularization with hypervascularization of consolidated segments contrasting with hypoperfusion of not affected segments, suggesting a dysregulation of the balance in perfusion between segments affected by COVID-19 and others.
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Affiliation(s)
- Cécile Maincent
- Pulmonary Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Christophe Perrin
- Pulmonary Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Gilles Chironi
- Check-up Unit, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Marie Baqué-Juston
- Radiology Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Frédéric Berthier
- Department of Biostatistics, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Benoît Paulmier
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Florent Hugonnet
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Claire Dittlot
- Pulmonary Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Ryan Lukas Farhad
- Pulmonary Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Julien Renvoise
- Pulmonary Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Benjamin Serrano
- Medical Physics Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Valérie Nataf
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - François Mocquot
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Olivia Keita-Perse
- Department of Infectious disease, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Yann-Erik Claessens
- Department of Emergency Medicine, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Marc Faraggi
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Avenue Pasteur, BP 480, 98012 Monaco, Monaco
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Mohan V, Bruin NM, van de Kamer JB, Sonke JJ, Vogel WV. The increasing potential of nuclear medicine imaging for the evaluation and reduction of normal tissue toxicity from radiation treatments. Eur J Nucl Med Mol Imaging 2021; 48:3762-3775. [PMID: 33687522 PMCID: PMC8484246 DOI: 10.1007/s00259-021-05284-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/24/2021] [Indexed: 11/26/2022]
Abstract
Radiation therapy is an effective treatment modality for a variety of cancers. Despite several advances in delivery techniques, its main drawback remains the deposition of dose in normal tissues which can result in toxicity. Common practices of evaluating toxicity, using questionnaires and grading systems, provide little underlying information beyond subjective scores, and this can limit further optimization of treatment strategies. Nuclear medicine imaging techniques can be utilised to directly measure regional baseline function and function loss from internal/external radiation therapy within normal tissues in an in vivo setting with high spatial resolution. This can be correlated with dose delivered by radiotherapy techniques to establish objective dose-effect relationships, and can also be used in the treatment planning step to spare normal tissues more efficiently. Toxicity in radionuclide therapy typically occurs due to undesired off-target uptake in normal tissues. Molecular imaging using diagnostic analogues of therapeutic radionuclides can be used to test various interventional protective strategies that can potentially reduce this normal tissue uptake without compromising tumour uptake. We provide an overview of the existing literature on these applications of nuclear medicine imaging in diverse normal tissue types utilising various tracers, and discuss its future potential.
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Affiliation(s)
- V Mohan
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
- Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - N M Bruin
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
- Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - J B van de Kamer
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - J-J Sonke
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Wouter V Vogel
- Department of Nuclear Medicine, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
- Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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de Nijs R, Sijtsema ND, Kruis MF, Jensen CV, Iversen M, Perch M, Mortensen J. Comparison of 81mKrypton and 99mTc-Technegas for ventilation single-photon emission computed tomography in severe chronic obstructive pulmonary disease. Nucl Med Commun 2021; 42:160-168. [PMID: 33105398 PMCID: PMC7808361 DOI: 10.1097/mnm.0000000000001314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/23/2020] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Ventilation and perfusion single-photon emission computed tomography combined with computed tomography (SPECT/CT) is a powerful tool to assess the state of the lungs in chronic obstructive pulmonary disease (COPD). 81mKrypton is a gaseous ventilation tracer and distributes similarly to air, but is not widely available and relatively expensive. 99mTc-Technegas is cheaper and has wider availability, but is an aerosol, which may deposit in hot spots as the severity of COPD increases. In this study, 81mKrypton and 99mTc-Technegas were compared quantitatively in patients with severe COPD. METHODS The penetration ratio, the heterogeneity index (with and without band filtering for relevant clinical sizes) and hot spot appearance were assessed in eleven patients with severe COPD that underwent simultaneous dual-isotope ventilation SPECT/CT with both 99mTc-Technegas and 81mKrypton. RESULTS Significant differences were found in the penetration ratio for the medium energy general purpose (MEGP) collimators, but not for the low energy general purpose (LEGP) collimators. The difference in the overall and the band filtered heterogeneity index was significant in most cases. All patients suffered from 99mTc-Technegas hot spots in at least one lung. Comparison of MEGP 81mKrypton and LEGP Technegas scans revealed similar results as the comparison for the MEGP collimators. CONCLUSION Caution should be taken when replacing 81mKrypton with 99mTc-Technegas as a ventilation tracer in patients with severe COPD as there are significant differences in the distribution of the tracers over the lungs. Furthermore, this patient group is prone to 99mTc-Technegas hot spots and might need additional scanning if hot spots severely hamper image interpretation.
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Affiliation(s)
- Robin de Nijs
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Nienke D. Sijtsema
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Department of Physics and Astronomy, Faculty of Science, VU University, Amsterdam, The Netherlands
| | | | | | - Martin Iversen
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Michael Perch
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Jann Mortensen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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Lee SJ, Park HJ. Single photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging for radiotherapy planning in patients with lung cancer: a meta-analysis. Sci Rep 2020; 10:14864. [PMID: 32913277 PMCID: PMC7483712 DOI: 10.1038/s41598-020-71445-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022] Open
Abstract
Functional imaging modalities enable practitioners to identify functional lung regions. This analysis evaluated the feasibility of nuclear medicine imaging to avoid doses to the functional lung in radiotherapy (RT) planning for patients with lung cancer. This systematic review and meta-analysis was carried out according to PRISMA-P guidelines. A search of EMBASE and PubMed for studies published throughout the last 20 years was performed using the following search criteria: (a) ‘lung cancer’ or ‘lung malignancy’ and (b) ‘radiotherapy’ or ‘radiation therapy’ or ‘RT planning’ and (c) ‘SPECT’ or ‘single positron emission computed tomography’ or ‘functional image.’ The analyzed planning parameters were the volumes of the normal lung that have received ≥ 10 Gy and ≥ 20 Gy of radiation (V10 and V20, respectively) and the mean lung dose (MLD). We compared the planning parameters obtained from anatomical RT planning and functional RT planning using perfusion or ventilation imaging (‘V10, V20 or MLD’ in anatomical plan vs. ‘fV10, fV20 or fMLD’ in functional plan). A total of 309 patients with 344 RT plan sets from 15 publications (11 perfusion SPECT, 2 ventilation SPECT, and 1 SPECT and 1 PET with both perfusion and ventilation) were included in the meta-analysis. The standard mean differences in planning parameters in functional plans using nuclear imaging were significantly reduced compared to those of anatomical plans (P < 0.01 for all): − 0.42 (95% confidence interval (CI) − 0.78 to − 0.07) for ‘V10 vs. fV10′, − 0.41 (95% CI − 0.64 to − 0.17) for ‘V20 vs. fV20′, and − 0.24 (95% CI − 0.45 to − 0.03) for ‘MLD vs. fMLD’. In subgroup analysis, the functional plan using perfusion was significantly lower than the anatomical plan in all planning parameters, but there was no significant difference for ventilation. RT planning with nuclear functional lung imaging has potential to reduce radiation-induced lung injury. Perfusion imaging seems to be more promising than ventilation imaging for all planning parameters. There were not enough studies using ventilation imaging to determine what the effect is on the lung plan parameters.
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Affiliation(s)
- Soo Jin Lee
- Department of Nuclear Medicine, Hanyang University Medical Center, 222-1 Wangsimni-ro, Seongdong-gu, Seoul, 04763, South Korea
| | - Hae Jin Park
- Department of Radiation Oncology, Hanyang University College of Medicine, 222-1 Wangsimni-ro, Seongdong-gu, Seoul, 04763, South Korea.
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68Ga-Labelled Carbon Nanoparticles for Ventilation PET/CT Imaging: Physical Properties Study and Comparison with Technegas®. Mol Imaging Biol 2020; 23:62-69. [PMID: 32886302 DOI: 10.1007/s11307-020-01532-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/07/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE The use of 68Ga-labelled carbon nanoparticles has been proposed for lung ventilation PET/CT imaging. However, no study has assessed the physical properties of 68Ga-labelled carbon nanoparticles. The aim of this study therefore was to evaluate the shape and size of 68Ga-labelled carbon nanoparticles, and to determine the composition of the aerosol, as opposed to 99mTc-labelled carbon nanoparticles aerosol. PROCEDURES 99mTc- and 68Ga-labelled carbon nanoparticles, stable gallium carbon nanoparticles, 0.9 % NaCl and 0.1 N HCl-based carbon nanoparticles were produced using an unmodified Technegas® generator, following the usual technique used for clinical Technegas® production. The shape and size of particles were studied by transmission electron microscopy (TEM) after decay of the radioactive samples. The composition of the 68Zn- and 99Tc-labelled carbon nanoparticles aerosols was assessed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis after decay of the 68Ga- and 99mTc-labelled carbon nanoparticles, respectively. RESULTS On TEM, all samples showed similar shape with hexagonally structured primary particles, agglomerated in clusters. The mean diameters of primary stable gallium carbon nanoparticles, 99Tc- and 68Zn-labelled carbon nanoparticles were 22.4 ± 10 nm, 20.9 ± 7.2 nm and 19.8 ± 11.7 nm, respectively. CONCLUSION Using Technegas® generator in the usual clinical way, 99mTc- and 68Ga-labelled carbon nanoparticles demonstrated similar shape and diameters in the same size range size. These results support the use of 68Ga-labelled carbon nanoparticles for the assessment of regional lung ventilation function with PET imaging.
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Letter to editor. Eur J Nucl Med Mol Imaging 2020; 47:1643-1644. [DOI: 10.1007/s00259-020-04813-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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LaFrance N, Fournier F. Radioaerosols and the updated EANM guideline in ventilation/perfusion imaging. Eur J Nucl Med Mol Imaging 2020; 47:1640-1642. [PMID: 32285154 PMCID: PMC7152692 DOI: 10.1007/s00259-020-04793-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 03/26/2020] [Indexed: 12/04/2022]
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Bajc M, Lindqvist A. Ventilation/Perfusion SPECT Imaging Diagnosing PE and Other Cardiopulmonary Diseases. Clin Nucl Med 2020. [DOI: 10.1007/978-3-030-39457-8_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Bajc M, Schümichen C, Grüning T, Lindqvist A, Le Roux PY, Alatri A, Bauer RW, Dilic M, Neilly B, Verberne HJ, Delgado Bolton RC, Jonson B. EANM guideline for ventilation/perfusion single-photon emission computed tomography (SPECT) for diagnosis of pulmonary embolism and beyond. Eur J Nucl Med Mol Imaging 2019; 46:2429-2451. [PMID: 31410539 PMCID: PMC6813289 DOI: 10.1007/s00259-019-04450-0] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/17/2019] [Indexed: 12/18/2022]
Abstract
These guidelines update the previous EANM 2009 guidelines on the diagnosis of pulmonary embolism (PE). Relevant new aspects are related to (a) quantification of PE and other ventilation/perfusion defects; (b) follow-up of patients with PE; (c) chronic PE; and (d) description of additional pulmonary physiological changes leading to diagnoses of left ventricular heart failure (HF), chronic obstructive pulmonary disease (COPD) and pneumonia. The diagnosis of PE should be reported when a mismatch of one segment or two subsegments is found. For ventilation, Technegas or krypton gas is preferred over diethylene triamine pentaacetic acid (DTPA) in patients with COPD. Tomographic imaging with V/PSPECT has higher sensitivity and specificity for PE compared with planar imaging. Absence of contraindications makes V/PSPECT an essential method for the diagnosis of PE. When V/PSPECT is combined with a low-dose CT, the specificity of the test can be further improved, especially in patients with other lung diseases. Pitfalls in V/PSPECT interpretation are discussed. In conclusion, V/PSPECT is strongly recommended as it accurately establishes the diagnosis of PE even in the presence of diseases like COPD, HF and pneumonia and has no contraindications.
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Affiliation(s)
- Marika Bajc
- Department of Clinical Sciences, Clinical Physiology and Nuclear Medicine, University of Lund, Lund, Sweden.
| | - Carl Schümichen
- University of Rostock, Formerly Clinic for Nuclear Medicine, Rostock, Germany
| | - Thomas Grüning
- Department of Nuclear Medicine, University Hospitals Plymouth, Plymouth, UK
| | - Ari Lindqvist
- Research Unit of Pulmonary Diseases, Clinical Research Institute, HUS Helsinki University Hospital, Helsinki, Finland
| | | | - Adriano Alatri
- Division of Angiology, Heart and Vessel Department, Lausanne University Hospital, Lausanne, Switzerland
| | - Ralf W Bauer
- RNS Gemeinschaftspraxis, Wiesbaden, Germany
- Department of Diagnostic and Interventional Radiology, Goethe University Frankfurt (Main), Frankfurt, Germany
| | - Mirza Dilic
- Clinic of Heart and Blood Vessel Disease, Clinical Center University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Brian Neilly
- Department of Nuclear Medicine, Royal Infirmary, Glasgow, UK
| | - Hein J Verberne
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Roberto C Delgado Bolton
- Department of Diagnostic Imaging (Radiology) and Nuclear Medicine, University Hospital San Pedro and Centre for Biomedical Research of La Rioja (CIBIR), Logroño, La Rioja, Spain
| | - Bjorn Jonson
- Department of Clinical Sciences, Clinical Physiology and Nuclear Medicine, University of Lund, Lund, Sweden
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Bailey DL, Roach PJ. A Brief History of Lung Ventilation and Perfusion Imaging Over the 50-Year Tenure of the Editors of Seminars in Nuclear Medicine. Semin Nucl Med 2019; 50:75-86. [PMID: 31843063 DOI: 10.1053/j.semnuclmed.2019.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ventilation/perfusion lung scan has been in continuous use for approximately half a century, the same lifetime as Seminars in Nuclear Medicine. Remarkably, the founding Editors-in-Chief have continued to guide the journal over this entire period. In this Feschrift issue celebrating their enormous contribution, we review the history of the lung scan, its highs and lows, the transition from planar to SPECT/CT V/Q scans, and the future that is in store in this age of multimodality functional imaging. We concur with the published view of one of the retiring editors (LMF) that V/Q scintigraphy is indeed alive and well and has a definite future in clinical medicine.
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Affiliation(s)
- Dale L Bailey
- Royal North Shore Hospital, Department of Nuclear Medicine, Sydney, Australia; University of Sydney, Faculty of Medicine & Health, Sydney, Australia.
| | - Paul J Roach
- Royal North Shore Hospital, Department of Nuclear Medicine, Sydney, Australia; University of Sydney, Faculty of Medicine & Health, Sydney, Australia
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A guide for a brave future for lung ventilation/perfusion tomography: the most important pulmonary nuclear medicine technique. Eur J Nucl Med Mol Imaging 2019; 46:2427-2428. [PMID: 31392369 DOI: 10.1007/s00259-019-04464-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 07/25/2019] [Indexed: 10/26/2022]
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Brudecki K, Borkowska E, Gorzkiewicz K, Kostkiewicz M, Mróz T. 99mTc activity concentrations in room air and resulting internal contamination of medical personnel during ventilation-perfusion lung scans. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2019; 58:469-475. [PMID: 30997611 PMCID: PMC6609588 DOI: 10.1007/s00411-019-00793-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/09/2019] [Indexed: 05/27/2023]
Abstract
This paper presents the results of measurements of 99mTc activity concentrations in indoor air in a nuclear medicine department and resulting estimated 99mTc intake by medical personnel. 99mTc air activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow, Poland, during ventilation-perfusion SPECT lung scans. Technetium from the air was collected by means of a mobile aerosol sampler with a Petryanov filter operating at an average flow rate of 10 dm3 min-1. Measured activities ranged from 99 ± 11 to 6.1 ± 0.5 kBq m-3. The resulting daily average intake of 99mTc by medical staff was estimated to be 5.4 kBq, 4.4 kBq, 3.0 kBq and 2.5 kBq, respectively, for male technicians, female technicians, male nurses and female nurses. Corresponding annual effective doses were 1.6 µSv for technicians and 1 µSv for nurses. The highest equivalent dose values were determined for extrathoracic (ET) airways: 5 µSv and 10 µSv for nurses and technicians, respectively. It is concluded that estimated annual absorbed doses are over three orders of magnitude lower than the dose limit established in the Polish Atomic Law Act and in recommendations of the International Commission on Radiological Protection for medical staff.
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Affiliation(s)
- K Brudecki
- Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342, Kraków, Poland.
| | - E Borkowska
- Electroradiology Department, Faculty of Health Sciences, Institute of Physiotherapy, Jagiellonian University, Collegium Medicum, Michalowskiego 12, 31-126, Kraków, Poland
- Nuclear Medicine Department, John Paul II Hospital, Prądnicka 80, Kraków, Poland
| | - K Gorzkiewicz
- Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342, Kraków, Poland
| | - M Kostkiewicz
- Heart and Vascular Diseases Department, Faculty of Medicine, Institute of Cardiology, Jagiellonian University, Collegium Medicum, Prądnicka 80, 31-202, Kraków, Poland
- Nuclear Medicine Department, John Paul II Hospital, Prądnicka 80, Kraków, Poland
| | - T Mróz
- Institute of Physics, Jagiellonian University, Kraków, Poland
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Bajc M, Lindqvist A. Ventilation/Perfusion SPECT Imaging—Diagnosing Other Cardiopulmonary Diseases Beyond Pulmonary Embolism. Semin Nucl Med 2019; 49:4-10. [DOI: 10.1053/j.semnuclmed.2018.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Pinkham DW, Negahdar M, Yamamoto T, Mittra E, Diehn M, Nair VS, Keall PJ, Maxim PG, Loo BW. A Feasibility Study of Single-inhalation, Single-energy Xenon-enhanced CT for High-resolution Imaging of Regional Lung Ventilation in Humans. Acad Radiol 2019; 26:38-49. [PMID: 29606339 DOI: 10.1016/j.acra.2018.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/01/2018] [Accepted: 03/07/2018] [Indexed: 11/30/2022]
Abstract
RATIONALE AND OBJECTIVES The objective of this study was to assess the feasibility of single-inhalation xenon-enhanced computed tomography (XeCT) to provide clinically practical, high-resolution pulmonary ventilation imaging to clinics with access to only a single-energy computed tomography scanner, and to reduce the subject's overall exposure to xenon by utilizing a higher (70%) concentration for a much shorter time than has been employed in prior studies. MATERIALS AND METHODS We conducted an institutional review board-approved prospective feasibility study of XeCT for 15 patients undergoing thoracic radiotherapy. For XeCT, we acquired two breath-hold single-energy computed tomography images of the entire lung with a single inhalation each of 100% oxygen and a mixture of 70% xenon and 30% oxygen, respectively. A video biofeedback system for coached patient breathing was used to achieve reproducible breath holds. We assessed the technical success of XeCT acquisition and side effects. We then used deformable image registration to align the breath-hold images with each other to accurately subtract them, producing a map of lung xenon distribution. Additionally, we acquired ventilation single-photon emission computed tomography-computed tomography (V-SPECT-CT) images for 11 of the 15 patients. For a comparative analysis, we partitioned each lung into 12 sectors, calculated the xenon concentration from the Hounsfield unit enhancement in each sector, and then correlated this with the corresponding V-SPECT-CT counts. RESULTS XeCT scans were tolerated well overall, with a mild (grade 1) dizziness as the only side effect in 5 of the 15 patients. Technical failures in five patients occurred because of inaccurate breathing synchronization with xenon gas delivery, leaving seven patients analyzable for XeCT and single-photon emission computed tomography correlation. Sector-wise correlations were strong (Spearman coefficient >0.75, Pearson coefficient >0.65, P value <.002) for two patients for whom ventilation deficits were visibly pronounced in both scans. Correlations were nonsignificant for the remaining five who had more homogeneous XeCT ventilation maps, as well as strong V-SPECT-CT imaging artifacts attributable to airway deposition of the aerosolized imaging agent. Qualitatively, XeCT demonstrated higher resolution and no central airway deposition artifacts compared to V-SPECT-CT. CONCLUSIONS In this pilot study, single-breath XeCT ventilation imaging was generally feasible for patients undergoing thoracic radiotherapy, using an imaging protocol that is clinically practical and potentially widely available. In the future, the xenon delivery failures can be addressed by straightforward technical improvements to the patient biofeedback coaching system.
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Affiliation(s)
- Daniel W Pinkham
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305
| | - Mohammadreza Negahdar
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305; Almaden Research Center, IBM Research, San Jose, California
| | - Tokihiro Yamamoto
- Department of Radiation Oncology, University of California, Davis, Sacramento, California
| | - Erik Mittra
- Department of Radiology, Stanford University, Stanford, California
| | - Maximilian Diehn
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305
| | - Viswam S Nair
- Division of Pulmonary & Critical Care Medicine, Stanford University, Stanford, California
| | - Paul J Keall
- Radiation Physics Laboratory, The University of Sydney, NSW, Australia
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, 875 Blake Wilbur Dr., Stanford, CA 94305.
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Cui T, Miller GW, Mugler JP, Cates GD, Mata JF, de Lange EE, Huang Q, Altes TA, Yin FF, Cai J. An initial investigation of hyperpolarized gas tagging magnetic resonance imaging in evaluating deformable image registration-based lung ventilation. Med Phys 2018; 45:5535-5542. [PMID: 30276819 DOI: 10.1002/mp.13223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/21/2018] [Accepted: 09/19/2018] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Deformable image registration (DIR)-based lung ventilation mapping is attractive due to its simplicity, and also challenging due to its susceptibility to errors and uncertainties. In this study, we explored the use of 3D Hyperpolarized (HP) gas tagging MRI to evaluate DIR-based lung ventilation. METHOD AND MATERIAL Three healthy volunteers included in this study underwent both 3D HP gas tagging MRI (t-MRI) and 3D proton MRI (p-MRI) using balanced steady-state free precession pulse sequence at end of inhalation and end of exhalation. We first obtained the reference displacement vector fields (DVFs) from the t-MRIs by tracking the motion of each tagging grid between the exhalation and the inhalation phases. Then, we determined DIR-based DVFs from the p-MRIs by registering the images at the two phases with two commercial DIR algorithms. Lung ventilations were calculated from both the reference DVFs and the DIR-based DVFs using the Jacobian method and then compared using cross correlation and mutual information. RESULTS The DIR-based lung ventilations calculated using p-MRI varied considerably from the reference lung ventilations based on t-MRI among all three subjects. The lung ventilations generated using Velocity AI were preferable for the better spatial homogeneity and accuracy compared to the ones using MIM, with higher average cross correlation (0.328 vs 0.262) and larger average mutual information (0.528 vs 0.323). CONCLUSION We demonstrated that different DIR algorithms resulted in different lung ventilation maps due to underlining differences in the DVFs. HP gas tagging MRI provides a unique platform for evaluating DIR-based lung ventilation.
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Affiliation(s)
- Taoran Cui
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, 08901, USA
| | - G Wilson Miller
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - John P Mugler
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - Gordon D Cates
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - Jaime F Mata
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - Eduard E de Lange
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, 22908, USA
| | - Qijie Huang
- Department of Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Talissa A Altes
- Department of Radiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA
| | - Fang-Fang Yin
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Jing Cai
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong, China
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Abstract
Ventilation-perfusion scintigraphy is a functional imaging biomarker that has the potential of captivating the heterogeneity of chronic obstructive pulmonary disease (COPD). It specifically images the distribution of ventilation and perfusion within the lungs, which is a critical pathophysiological component of COPD. The extent of ventilation defects and ventilation inhomogeneity, as well as the ventilation-perfusion ratio distribution thus correlate with severity of disease. Furthermore, specific scintigraphic patterns, such as the "stripe sign" may detect centrilobular emphysematous lesions with a higher sensitivity than other imaging techniques. Although ventilation-perfusion scintigraphy may conceivably detect COPD before any specific changes can be detected by spirometry or high-resolution CT, it is currently mostly used in the workup of lung volume reduction treatment, and for diagnosing various complications and comorbidities of COPD when combined with low-dose CT.
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Affiliation(s)
- Jann Mortensen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; Department of Medicine, The National Hospital, Torshavn, Faroe Islands.
| | - Ronan M G Berg
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark; Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
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Guo F, Capaldi DPI, McCormack DG, Fenster A, Parraga G. A framework for Fourier-decomposition free-breathing pulmonary 1 H MRI ventilation measurements. Magn Reson Med 2018; 81:2135-2146. [PMID: 30362609 DOI: 10.1002/mrm.27527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 08/20/2018] [Indexed: 12/20/2022]
Abstract
PURPOSE To develop a rapid Fourier decomposition (FD) free-breathing pulmonary 1 H MRI (FDMRI) image processing and biomarker pipeline for research use. METHODS We acquired MRI in 20 asthmatic subjects using a balanced steady-state free precession (bSSFP) sequence optimized for ventilation imaging. 2D 1 H MRI series were segmented by enforcing the spatial similarity between adjacent images and the right-to-left lung volume-ratio. The segmented lung series were co-registered using a coarse-to-fine deformable registration framework that used dual optimization techniques. All pairwise registrations were implemented in parallel and FD was performed to generate 2D ventilation-weighted maps and ventilation-defect-percent (VDP). Lung segmentation and registration accuracy were evaluated by comparing algorithm and manual lung-masks, deformed manual lung-masks, and fiducials in the moving and fixed images using Dice-similarity-coefficient (DSC), mean-absolute-distance (MAD), and target-registration-error (TRE). The relationship of FD-VDP and 3 He-VDP was evaluated using the Pearson-correlation-coefficient (r) and Bland Altman analysis. Algorithm reproducibility was evaluated using the coefficient-of-variation (CoV) and intra-class-correlation-coefficient (ICC) for segmentation, registration, and FD-VDP components. RESULTS For lung segmentation, there was a DSC of 95 ± 1.5% and MAD of 2.3 ± 0.5 mm, and for registration there was a DSC of 97 ± 0.8%, MAD of 1.6 ± 0.4 mm and TRE of 3.6 ± 1.2 mm. Reproducibility for segmentation DSC (CoV/ICC = 0.5%/0.92), registration TRE (CoV/ICC = 0.4%/0.98), and FD-VDP (Cov/ICC = 3.9%/0.97) was high. The pipeline required 10 min/subject. FD-VDP was correlated with 3 He-VDP (r = 0.69, P < 0.001) although there was a bias toward lower FD-VDP (bias = -4.9%). CONCLUSIONS We developed and evaluated a pipeline that provides a rapid and precise method for FDMRI ventilation maps.
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Affiliation(s)
- Fumin Guo
- Robarts Research Institute, Western University, London, Ontario, Canada.,Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Dante P I Capaldi
- Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - David G McCormack
- Division of Respirology, Department of Medicine, Western University, London, Ontario, Canada
| | - Aaron Fenster
- Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Grace Parraga
- Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada.,Division of Respirology, Department of Medicine, Western University, London, Ontario, Canada
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Jögi J, Al-Mashat M, Rådegran G, Bajc M, Arheden H. Diagnosing and grading heart failure with tomographic perfusion lung scintigraphy: validation with right heart catheterization. ESC Heart Fail 2018; 5:902-910. [PMID: 30015395 PMCID: PMC6165926 DOI: 10.1002/ehf2.12317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/30/2018] [Indexed: 12/01/2022] Open
Abstract
Aims Pulmonary congestion remains a diagnostic challenge in patients with heart failure (HF). The recommended method, chest X‐ray (CXR), lacks in accuracy, whereas quantitative tomographic lung scintigraphy [ventilation/perfusion single‐photon emission computed tomography (V/P SPECT)] has shown promising results but needs independent validation. The aim of this study is to evaluate V/P SPECT as a non‐invasive method to assess and quantify pulmonary congestion in HF patients, using right heart catheterization as reference method. The secondary objective was to investigate the performance of V/P SPECT in the clinical setting compared with CXR. Methods and results Forty‐six consecutive patients with HF that were under consideration for heart transplantation were studied prospectively. All participants were examined with V/P SPECT, CXR, and right heart catheterization. Pulmonary artery wedge pressure served as reference method. Quantitative perfusion gradients were derived from V/P SPECT images. Ventilation/perfusion single‐photon emission computed tomography images were also assessed both by expert readers and clinical nuclear medicine physicians. Expert readers correctly identified 87% of all patients with an elevated pulmonary artery wedge pressure > 15 mmHg. The average sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for V/P SPECT assessed by the expert readers were 87%, 72%, 85%, and 75%, respectively. In the clinical nuclear medicine setting, V/P SPECT had 87% sensitivity, 63% specificity, 81% PPV, and 71% NPV. Clinically, V/P SPECT outperformed CXR, which had 27% sensitivity, 75% specificity, 67% PPV, and 35% NPV. Conclusions Ventilation/perfusion single‐photon emission computed tomography can be used as a non‐invasive method to diagnose and quantify pulmonary congestion in patients with HF and is more accurate than CXR in diagnosing pulmonary congestion in the clinical setting.
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Affiliation(s)
- Jonas Jögi
- Department of Clinical Sciences Lund, Department of Clinical Physiology, Lund University, Skåne University Hospital, Lund, Sweden
| | - Mariam Al-Mashat
- Department of Clinical Sciences Lund, Department of Clinical Physiology, Lund University, Skåne University Hospital, Lund, Sweden
| | - Göran Rådegran
- Department of Clinical Sciences Lund, Department of Cardiology, Heart and Lung Medicine, Lund University, Skåne University Hospital, Lund, Sweden
| | - Marika Bajc
- Department of Clinical Sciences Lund, Department of Clinical Physiology, Lund University, Skåne University Hospital, Lund, Sweden
| | - Håkan Arheden
- Department of Clinical Sciences Lund, Department of Clinical Physiology, Lund University, Skåne University Hospital, Lund, Sweden
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Hegi-Johnson F, Keall P, Barber J, Bui C, Kipritidis J. Evaluating the accuracy of 4D-CT ventilation imaging: First comparison with Technegas SPECT ventilation. Med Phys 2017; 44:4045-4055. [PMID: 28477378 DOI: 10.1002/mp.12317] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 03/21/2017] [Accepted: 04/05/2017] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Computed tomography ventilation imaging (CTVI) is a highly accessible functional lung imaging modality that can unlock the potential for functional avoidance in lung cancer radiation therapy. Previous attempts to validate CTVI against clinical ventilation single-photon emission computed tomography (V-SPECT) have been hindered by radioaerosol clumping artifacts. This work builds on those studies by performing the first comparison of CTVI with 99m Tc-carbon ('Technegas'), a clinical V-SPECT modality featuring smaller radioaerosol particles with less clumping. METHODS Eleven lung cancer radiotherapy patients with early stage (T1/T2N0) disease received treatment planning four-dimensional CT (4DCT) scans paired with Technegas V/Q-SPECT/CT. For each patient, we applied three different CTVI methods. Two of these used deformable image registration (DIR) to quantify breathing-induced lung density changes (CTVIDIR-HU ), or breathing-induced lung volume changes (CTVIDIR-Jac ) between the 4DCT exhale/inhale phases. A third method calculated the regional product of air-tissue densities (CTVIHU ) and did not involve DIR. Corresponding CTVI and V-SPECT scans were compared using the Dice similarity coefficient (DSC) for functional defect and nondefect regions, as well as the Spearman's correlation r computed over the whole lung. The DIR target registration error (TRE) was quantified using both manual and computer-selected anatomic landmarks. RESULTS Interestingly, the overall best performing method (CTVIHU ) did not involve DIR. For nondefect regions, the CTVIHU , CTVIDIR-HU , and CTVIDIR-Jac methods achieved mean DSC values of 0.69, 0.68, and 0.54, respectively. For defect regions, the respective DSC values were moderate: 0.39, 0.33, and 0.44. The Spearman r-values were generally weak: 0.26 for CTVIHU , 0.18 for CTVIDIR-HU , and -0.02 for CTVIDIR-Jac . The spatial accuracy of CTVI was not significantly correlated with TRE, however the DIR accuracy itself was poor with TRE > 3.6 mm on average, potentially indicative of poor quality 4DCT. Q-SPECT scans achieved good correlations with V-SPECT (mean r > 0.6), suggesting that the image quality of Technegas V-SPECT was not a limiting factor in this study. CONCLUSIONS We performed a validation of CTVI using clinically available 4DCT and Technegas V/Q-SPECT for 11 lung cancer patients. The results reinforce earlier findings that the spatial accuracy of CTVI exhibits significant interpatient and intermethod variability. We propose that the most likely factor affecting CTVI accuracy was poor image quality of clinical 4DCT.
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Affiliation(s)
- Fiona Hegi-Johnson
- Radiation Physics Laboratory, Faculty of Medicine, Sydney University, Camperdown, NSW, 2006, Australia.,Department of Medical Physics, School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW, 2300, Australia.,Radiation Oncology Centre, Seventh Day Adventist Hospital, Wahroonga, NSW 2076, Australia.,Department of Radiation Oncology, Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Vic., 3000, Australia
| | - Paul Keall
- Radiation Physics Laboratory, Faculty of Medicine, Sydney University, Camperdown, NSW, 2006, Australia
| | - Jeff Barber
- Crown Princess Mary Cancer Care Centre, Blacktown Hospital, Blacktown, NSW, 2148, Australia
| | - Chuong Bui
- Department of Nuclear Medicine, Nepean Hospital, Nepean, NSW, 2750, Australia
| | - John Kipritidis
- Radiation Physics Laboratory, Faculty of Medicine, Sydney University, Camperdown, NSW, 2006, Australia.,Department of Radiotherapy, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia
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31
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Bajc M, Chen Y, Wang J, Li XY, Shen WM, Wang CZ, Huang H, Lindqvist A, He XY. Identifying the heterogeneity of COPD by V/P SPECT: a new tool for improving the diagnosis of parenchymal defects and grading the severity of small airways disease. Int J Chron Obstruct Pulmon Dis 2017; 12:1579-1587. [PMID: 28603413 PMCID: PMC5457181 DOI: 10.2147/copd.s131847] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Introduction Airway obstruction and possible concomitant pulmonary diseases in COPD cannot be identified conventionally with any single diagnostic tool. We aimed to diagnose and grade COPD severity and identify pulmonary comorbidities associated with COPD with ventilation/perfusion single-photon emission computed tomography (V/P SPECT) using Technegas as the functional ventilation imaging agent. Methods 94 COPD patients (aged 43–86 years, Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages I–IV) were examined with V/P SPECT and spirometry. Ventilation and perfusion defects were analyzed blindly according to the European guidelines. Penetration grade of Technegas in V SPECT measured the degree of obstructive small airways disease. Total preserved lung function and penetration grade of Technegas in V SPECT were assessed by V/P SPECT and compared to GOLD stages and spirometry. Results Signs of small airway obstruction in the ventilation SPECT images were found in 92 patients. Emphysema was identified in 81 patients. Two patients had no signs of COPD, but both of them had a pulmonary embolism, and in one of them we also suspected a lung tumor. The penetration grade of Technegas in V SPECT and total preserved lung function correlated significantly to GOLD stages (r=0.63 and −0.60, respectively, P<0.0001). V/P SPECT identified pulmonary embolism in 30 patients (32%). A pattern typical for heart failure was present in 26 patients (28%). Parenchymal changes typical for pneumonia or lung tumor were present in several cases. Conclusion V/P SPECT, using Technegas as the functional ventilation imaging agent, is a new tool to diagnose COPD and to grade its severity. Additionally, it revealed heterogeneity of COPD caused by pulmonary comorbidities. The characteristics of these comorbidities suggest their significant impact in clarifying symptoms, and also their influence on the prognosis.
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Affiliation(s)
- M Bajc
- Department of Clinical Science Physiology and Nuclear Medicine, Skåne University Hospital, Lund, Sweden
| | - Y Chen
- Respiratory Department, Changzheng Hospital, Shanghai
| | - J Wang
- Respiratory Department, Xinqiao Hospital, Chongqing
| | - X Y Li
- Respiratory Department, Huadong Hospital, Shanghai, China
| | - W M Shen
- Respiratory Department, Huadong Hospital, Shanghai, China
| | - C Z Wang
- Respiratory Department, Xinqiao Hospital, Chongqing
| | - H Huang
- Respiratory Department, Changzheng Hospital, Shanghai
| | - A Lindqvist
- Department of Pulmonary Medicine, Heart and Lung Center, Helsinki University Hospital and Helsinki University, Helsinki, Finland
| | - X Y He
- Suzhou University Affiliated Tumor Hospital, Wuxi, China
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Bailey DL, Eslick EM, Schembri GP, Roach PJ. (68)Ga PET Ventilation and Perfusion Lung Imaging-Current Status and Future Challenges. Semin Nucl Med 2017; 46:428-35. [PMID: 27553468 DOI: 10.1053/j.semnuclmed.2016.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gallium-68 ((68)Ga) is a positron-emitting radionuclide suitable for positron emission tomography (PET) imaging that has a number of convenient features-it has a physical half life of 68 minutes, it is generator produced at the PET facility and needs no local cyclotron, and being a radiometal is able to be chelated to a number of useful molecules for diagnostic imaging with PET. (68)Ga has recently been investigated as a radiotracer for ventilation and perfusion (V/Q) lung imaging. It is relatively easy to produce both V/Q radiopharmaceuticals labeled with (68)Ga for PET studies, it offers higher spatial resolution than equivalent SPECT studies, the short half life allows for multiple (repeated) scans on the same day, and low amounts of radiotracer can be used thus limiting the radiation dose to the subject. In the usual clinical setting requiring a V/Q scan, that of suspected pulmonary embolism, the role of (68)Ga V/Q PET may be limited from a logistical perspective, however, in nonacute applications such as lung function evaluation, radiotherapy treatment planning, and respiratory physiology investigations it would appear to be an ideal modality to employ.
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Affiliation(s)
- Dale L Bailey
- Department of Nuclear Medicine, Royal North Shore Hospital, Sydney, Australia; Faculty of Health Sciences, University of Sydney, Sydney, Australia.
| | - Enid M Eslick
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Geoffrey P Schembri
- Department of Nuclear Medicine, Royal North Shore Hospital, Sydney, Australia; Sydney Medical School, University of Sydney, Sydney, Australia
| | - Paul J Roach
- Department of Nuclear Medicine, Royal North Shore Hospital, Sydney, Australia; Sydney Medical School, University of Sydney, Sydney, Australia
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33
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Milà M, Bechini J, Vázquez A, Vallejos V, Tenesa M, Espinal A, Fraile M, Monreal M. Acute pulmonary embolism detection with ventilation/perfusion SPECT combined with full dose CT: What is the best option? Rev Esp Med Nucl Imagen Mol 2017. [DOI: 10.1016/j.remnie.2017.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Guo F, Svenningsen S, Kirby M, Capaldi DP, Sheikh K, Fenster A, Parraga G. Thoracic CT-MRI coregistration for regional pulmonary structure-function measurements of obstructive lung disease. Med Phys 2017; 44:1718-1733. [PMID: 28206676 DOI: 10.1002/mp.12160] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/06/2017] [Accepted: 02/08/2017] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Recent pulmonary imaging research has revealed that in patients with chronic obstructive pulmonary disease (COPD) and asthma, structural and functional abnormalities are spatially heterogeneous. This novel information may help optimize treatment in individual patients, monitor interventional efficacy, and develop new treatments. Moreover, by automating the measurement of regional biomarkers for the 19 different anatomical lung segments, there is an opportunity to embed imaging biomarkers into clinically acceptable clinical workflows and improve lung disease clinical care. Therefore, to exploit the regional structure-function information provided by thoracic imaging, and as a first step toward this goal, our objective was to develop a fully automated registration pipeline for thoracic x-ray computed tomography (CT) and inhaled gas functional magnetic resonance imaging (MRI) whole lung and segmental structure-function biomarkers. METHODS Thirty-five patients including 15 severe, poorly controlled asthmatics and 20 COPD patients [classified according to the global initiative for chronic obstructive lung disease (GOLD) criteria)] provided written informed consent to a study protocol approved by Health Canada and underwent pulmonary function tests, MRI, and CT during a single 2-hour visit. Using this diverse patient dataset, we developed and evaluated a joint deformable registration approach to simultaneously coregister CT with both 1 H and 3 He MRI by enforcing the similarity of the deformation fields from the two individual registrations. We derived a simpler model that was equivalent to the original challenging optimization problem through variational analysis and the simpler model gave rise to an efficient numerical solver that was parallelized on a graphics processing unit. The coregistered CT-3 He MRI and whole lung/segmental lung masks were used to generate whole lung and segmental 3 He MRI ventilation defect percent (VDP). To estimate fiducial localization reproducibility, a single observer manually identified 109 pairs of CT and 3 He MRI fiducials for 35 patient images on five separate occasions and determined the fiducial localization error (FLE). CT-3 He MRI registration accuracy was evaluated using the target registration error (TRE). Whole lung VDP generated using the algorithm was compared with VDP generated using a previously validated semiautomated approach and computational efficiency was evaluated using run time. RESULTS In 35 patients including 15 with severe asthma and 20 with COPD, mean forced expiratory volume in 1 s (FEV1 ) was 63±24%pred and FEV1 /forced vital capacity (FVC) was 54 ± 17%. FLE was 0.16 mm and 0.34 mm for 3 He MRI and CT, respectively. TRE was 4.5 ± 2.0 mm, 4.0 ± 1.7 mm, 4.8 ± 2.3 mm for asthma, COPD GOLD II, and GOLD III groups, respectively, with a mean of 4.4 ± 2.0 mm for the entire dataset. TRE was significantly improved for joint CT-1 H/3 He MRI registration compared with CT-1 H MRI rigid registration (P < 0.0001). Whole lung VDP generated using the pipeline was not significantly different (P = 0.37) compared to a semiautomated method with which it was strongly correlated (r = 0.93, P < 0.0001). The fully automated pipeline required 11 ± 0.4 min to generate whole lung and segmental VDP. CONCLUSIONS For a diverse group of patients with COPD and asthma, whole lung and segmental VDP was measured using an automated lung image analysis pipeline which provides a way to incorporate lung functional biomarkers into clinical research and patient care.
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Affiliation(s)
- Fumin Guo
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada
| | - Sarah Svenningsen
- Robarts Research Institute, The University of Western Ontario, London, Canada
| | - Miranda Kirby
- James Hogg Research Centre, St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | - Dante Pi Capaldi
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Medical Biophysics, The University of Western Ontario, London, Canada
| | - Khadija Sheikh
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Medical Biophysics, The University of Western Ontario, London, Canada
| | - Aaron Fenster
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada.,Department of Medical Biophysics, The University of Western Ontario, London, Canada
| | - Grace Parraga
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Canada.,Department of Medical Biophysics, The University of Western Ontario, London, Canada
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Milà M, Bechini J, Vázquez A, Vallejos V, Tenesa M, Espinal A, Fraile M, Monreal M. Acute pulmonary embolism detection with ventilation/perfusion SPECT combined with full dose CT: What is the best option? Rev Esp Med Nucl Imagen Mol 2017; 36:139-145. [PMID: 28185782 DOI: 10.1016/j.remn.2016.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/21/2016] [Accepted: 11/01/2016] [Indexed: 11/16/2022]
Abstract
AIM To compare diagnostic accuracy of Ventilation/Perfusion (V/P) single-photon emission computed tomography (SPECT) combined with simultaneous full-dose CT with a hybrid SPECT/CT scanner versus planar ventilation/perfusion (V/P) SPECT and CT angiography (CTA) in patients suspected with acute pulmonary embolism (PE). METHODS Between 2009 and 2011, consecutive patients suspected of acute PE were referred for V/P SPECT/CT (reviewed board approved study). A contrast agent was administered to patients who had no contraindications. Non-contrast V/P SPECT/CT was performed on the remaining patients. All patients were followed-up for at least 3 months. RESULTS A total of 314 patients were available during the study period, with the diagnosis of PE confirmed in 70 (22.29%) of them. The overall population sensitivity and specificity was 90.91% and 92.44%, respectively for V/P SPECT, 80% and 99.15%, respectively, for CTA, and 95.52% and 97.08% for V/P SPECT/CT. SPECT/CT performed better than V/P SPECT (AUC differences=0.0419, P=0.0043, 95% CI; 0.0131-0.0706) and CTA (AUC differences=0.0681, P=0.0208, 95% CI; 0.0103-0.1259)). Comparing imaging modalities when contrast agent could be administered, sensitivity and specificity increased and V/P SPECT/CT was significantly better than CTA (AUC differences=0.0681, P=0.0208, 95% CI; 0.0103-0.1259) and V/P SPECT (AUC differences=0.0659, P=0.0052, 95% CI; 0.0197-0.1121). In case of non-contrast enhancement, there was non-significant increase of specificity. Secondary findings on CT impacted patient management in 14.65% of cases. CONCLUSION Our study shows that combined V/P SPECT/CT scanning has a higher diagnostic accuracy for detecting acute PE than V/P SPECT and CTA alone. When feasible, V/P SPECT/CT with contrast enhancement is the best option.
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Affiliation(s)
- M Milà
- Department of Nuclear Medicine (ICS-IDI), Hospital Universitari Germans Trias i Pujol, Badalona, Spain.
| | - J Bechini
- Department of Radiology, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - A Vázquez
- Applied Statistics Service, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - V Vallejos
- Department of Nuclear Medicine (ICS-IDI), Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - M Tenesa
- Department of Radiology, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - A Espinal
- Applied Statistics Service, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M Fraile
- Department of Nuclear Medicine (ICS-IDI), Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - M Monreal
- Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
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Capaldi DPI, Guo F, Parraga G. Imaging how and where we breathe oxygen: another Big Short? J Thorac Dis 2016; 8:E204-7. [PMID: 27076971 DOI: 10.21037/jtd.2016.01.83] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Dante P I Capaldi
- 1 Robarts Research Institute, 2 Department of Medical Biophysics, 3 Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada
| | - Fumin Guo
- 1 Robarts Research Institute, 2 Department of Medical Biophysics, 3 Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada
| | - Grace Parraga
- 1 Robarts Research Institute, 2 Department of Medical Biophysics, 3 Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada
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Schembri GP, Roach PJ, Bailey DL, Freeman L. Artifacts and Anatomical Variants Affecting Ventilation and Perfusion Lung Imaging. Semin Nucl Med 2015; 45:373-91. [DOI: 10.1053/j.semnuclmed.2015.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Siva S, Hardcastle N, Kron T, Bressel M, Callahan J, MacManus MP, Shaw M, Plumridge N, Hicks RJ, Steinfort D, Ball DL, Hofman MS. Ventilation/Perfusion Positron Emission Tomography--Based Assessment of Radiation Injury to Lung. Int J Radiat Oncol Biol Phys 2015; 93:408-17. [PMID: 26275510 DOI: 10.1016/j.ijrobp.2015.06.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/11/2015] [Accepted: 06/02/2015] [Indexed: 12/25/2022]
Abstract
PURPOSE To investigate (68)Ga-ventilation/perfusion (V/Q) positron emission tomography (PET)/computed tomography (CT) as a novel imaging modality for assessment of perfusion, ventilation, and lung density changes in the context of radiation therapy (RT). METHODS AND MATERIALS In a prospective clinical trial, 20 patients underwent 4-dimensional (4D)-V/Q PET/CT before, midway through, and 3 months after definitive lung RT. Eligible patients were prescribed 60 Gy in 30 fractions with or without concurrent chemotherapy. Functional images were registered to the RT planning 4D-CT, and isodose volumes were averaged into 10-Gy bins. Within each dose bin, relative loss in standardized uptake value (SUV) was recorded for ventilation and perfusion, and loss in air-filled fraction was recorded to assess RT-induced lung fibrosis. A dose-effect relationship was described using both linear and 2-parameter logistic fit models, and goodness of fit was assessed with Akaike Information Criterion (AIC). RESULTS A total of 179 imaging datasets were available for analysis (1 scan was unrecoverable). An almost perfectly linear negative dose-response relationship was observed for perfusion and air-filled fraction (r(2)=0.99, P<.01), with ventilation strongly negatively linear (r(2)=0.95, P<.01). Logistic models did not provide a better fit as evaluated by AIC. Perfusion, ventilation, and the air-filled fraction decreased 0.75 ± 0.03%, 0.71 ± 0.06%, and 0.49 ± 0.02%/Gy, respectively. Within high-dose regions, higher baseline perfusion SUV was associated with greater rate of loss. At 50 Gy and 60 Gy, the rate of loss was 1.35% (P=.07) and 1.73% (P=.05) per SUV, respectively. Of 8/20 patients with peritumoral reperfusion/reventilation during treatment, 7/8 did not sustain this effect after treatment. CONCLUSIONS Radiation-induced regional lung functional deficits occur in a dose-dependent manner and can be estimated by simple linear models with 4D-V/Q PET/CT imaging. These findings may inform future studies of functional lung avoidance using V/Q PET/CT.
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Affiliation(s)
- Shankar Siva
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Australia.
| | - Nicholas Hardcastle
- Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Tomas Kron
- Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Mathias Bressel
- Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Jason Callahan
- Centre for Molecular Imaging, Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Michael P MacManus
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Mark Shaw
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Nikki Plumridge
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Rodney J Hicks
- Centre for Molecular Imaging, Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia; Department of Medicine, University of Melbourne, Parkville, Australia
| | - Daniel Steinfort
- Department of Medicine, University of Melbourne, Parkville, Australia; Department of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - David L Ball
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Michael S Hofman
- Centre for Molecular Imaging, Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia; Department of Medicine, University of Melbourne, Parkville, Australia
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Magnetic resonance imaging biomarkers of chronic obstructive pulmonary disease prior to radiation therapy for non-small cell lung cancer. Eur J Radiol Open 2015; 2:81-9. [PMID: 26937440 PMCID: PMC4750562 DOI: 10.1016/j.ejro.2015.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 05/15/2015] [Indexed: 11/21/2022] Open
Abstract
Three imaging phenotypes of COPD and ventilation heterogeneity. We examine relationships for non-tumour lobe ventilation voids and clinical tests. Smoking history and airflow obstruction were diagnostics for imaging phenotypes.
Objective In this prospectively planned interim-analysis, the prevalence of chronic obstructive lung disease (COPD) phenotypes was determined using magnetic resonance imaging (MRI) and X-ray computed tomography (CT) in non-small-cell-lung-cancer (NSCLC) patients. Materials and methods Stage-III-NSCLC patients provided written informed consent for pulmonary function tests, imaging and the 6-min-walk-test. Ventilation defect percent (VDP) and CT lung density (relative-of-CT-density-histogram <−950, RA950) were measured. Patients were classified into three subgroups based on qualitative and quantitative COPD and tumour-specific imaging phenotypes: (1) tumour-specific ventilation defects (TSD), (2) tumour-specific and other ventilation defects without emphysema (TSDV), and, (3) tumour-specific and other ventilation defects with emphysema (TSDVE). Results Seventeen stage-III NSCLC patients were evaluated (68 ± 7 years, 7 M/10 F, mean FEV1 = 77%pred) including seven current and 10 ex-smokers and eight patients with a prior lung disease diagnosis. There was a significant difference for smoking history (p = .02) and FEV1/FVC (p = .04) for subgroups classified using quantitative imaging. Patient subgroups classified using qualitative imaging findings were significantly different for emphysema (RA950, p < .001). There were significant relationships for whole-lung VDP (p < .05), but not RECIST or tumour-lobe VDP measurements with pulmonary function and exercise measurements. Preliminary analysis for non-tumour burden ventilation abnormalities using Reader-operator-characteristic (ROC) curves reflected a 94% classification rate for smoking pack-years, 93% for FEV1/FVC and 82% for RA950. ROC sensitivity/specificity/positive/negative likelihood ratios were also generated for pack-years, (0.92/0.80/4.6/0.3), FEV1/FVC (0.92/0.80/4.6/0.3), RA950 (0.92/0.80/4.6/0.3) and RECIST (0.58/0.80/2.9/1.1). Conclusions In this prospectively planned interim-analysis of a larger clinical trial, NSCLC patients were classified based on COPD imaging phenotypes. A proof-of-concept evaluation showed that FEV1/FVC and smoking history identified NSCLC patients with ventilation abnormalities appropriate for functional lung avoidance radiotherapy.
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Froeling V, Heimann U, Huebner RH, Kroencke TJ, Maurer MH, Doellinger F, Geisel D, Hamm B, Brenner W, Schreiter NF. Ventilation/perfusion SPECT or SPECT/CT for lung function imaging in patients with pulmonary emphysema? Ann Nucl Med 2015; 29:528-34. [PMID: 25939639 DOI: 10.1007/s12149-015-0976-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 04/13/2015] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the utility of attenuation correction (AC) of V/P SPECT images for patients with pulmonary emphysema. MATERIALS AND METHODS Twenty-one patients (mean age 67.6 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. AC/non-AC V/P SPECT images were compared visually and semiquantitatively. Visual comparison of AC/non-AC images was based on a 5-point likert scale. Semiquantitative comparison assessed absolute counts per lung (aCpLu) and lung lobe (aCpLo) for AC/non-AC images using software-based analysis; percentage counts (PC = (aCpLo/aCpLu) × 100) were calculated. Correlation between AC/non-AC V/P SPECT images was analyzed using Spearman's rho correlation coefficient; differences were tested for significance with the Wilcoxon rank sum test. RESULTS Visual analysis revealed high conformity for AC and non-AC V/P SPECT images. Semiquantitative analysis of PC in AC/non-AC images had an excellent correlation and showed no significant differences in perfusion (ρ = 0.986) or ventilation (ρ = 0.979, p = 0.809) SPECT/CT images. CONCLUSION AC of V/P SPECT images for lung lobe-based function imaging in patients with pulmonary emphysema do not improve visual or semiquantitative image analysis.
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Affiliation(s)
- Vera Froeling
- Department of Radiology, Charité, Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany,
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Siva S, Devereux T, Ball DL, MacManus MP, Hardcastle N, Kron T, Bressel M, Foroudi F, Plumridge N, Steinfort D, Shaw M, Callahan J, Hicks RJ, Hofman MS. Ga-68 MAA Perfusion 4D-PET/CT Scanning Allows for Functional Lung Avoidance Using Conformal Radiation Therapy Planning. Technol Cancer Res Treat 2015; 15:114-21. [PMID: 25575575 DOI: 10.1177/1533034614565534] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 12/01/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Ga-68-macroaggregated albumin ((68)Ga-perfusion) positron emission tomography/computed tomography (PET/CT) is a novel imaging technique for the assessment of functional lung volumes. The purpose of this study was to use this imaging technique for functional adaptation of definitive radiotherapy plans in patients with non-small cell lung cancer (NSCLC). METHODS This was a prospective clinical trial of patients with NSCLC who received definitive 3-dimensional (3D) conformal radiotherapy to 60 Gy in 30 fx and underwent pretreatment respiratory-gated (4-dimensional [4D]) perfusion PET/CT. The "perfused" lung volume was defined as all lung parenchyma taking up radiotracer, and the "well-perfused" lung volume was contoured using a visually adapted threshold of 30% maximum standardized uptake value (SUV max). Alternate 3D conformal plans were subsequently created and optimized to avoid perfused and well-perfused lung volumes. Functional dose volumetrics were compared using mean lung dose (MLD), V5 (volume receiving 5 Gy or more), V10, V20, V30, V40, V50, and V60 parameters. RESULTS Fourteen consecutive patients had alternate radiotherapy plans created based on functional lung volumes. When considering the original treatment plan, the dose to perfused and well-perfused functional lung volumes was similar to that of the conventional anatomical lung volumes with an average MLD of 12.15, 12.67, and 12.11 Gy, respectively. Plans optimized for well-perfused lung improved functional V30, V40, V50, and V60 metrics (all P values <.05). The functional MLD of well-perfused lung was improved by a median of 0.86 Gy, P < .01. However, plans optimized for perfused lung only showed significant improvement in the functional V60 dose parameter (median 1.00%, P = .04) but at a detriment of a worse functional V5 (median 3.33%, P = .05). CONCLUSIONS This study demonstrates proof of principle that 4D-perfusion PET/CT may enable functional lung avoidance during treatment planning of patients with NSCLC. Radiotherapy plans adapted to well-perfused but not perfused functional lung volumes allow for reduction in dose to functional lung using 3D conformal radiotherapy.
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Affiliation(s)
- Shankar Siva
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Thomas Devereux
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - David L Ball
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Michael P MacManus
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Nicholas Hardcastle
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Tomas Kron
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Mathias Bressel
- Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Farshad Foroudi
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Nikki Plumridge
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Daniel Steinfort
- Division of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Mark Shaw
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Jason Callahan
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - Rodney J Hicks
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Michael S Hofman
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
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Hoover DA, Capaldi DP, Sheikh K, Palma DA, Rodrigues GB, Dar AR, Yu E, Dingle B, Landis M, Kocha W, Sanatani M, Vincent M, Younus J, Kuruvilla S, Gaede S, Parraga G, Yaremko BP. Functional lung avoidance for individualized radiotherapy (FLAIR): study protocol for a randomized, double-blind clinical trial. BMC Cancer 2014; 14:934. [PMID: 25496482 PMCID: PMC4364501 DOI: 10.1186/1471-2407-14-934] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 11/05/2014] [Indexed: 12/25/2022] Open
Abstract
Background Although radiotherapy is a key component of curative-intent treatment for locally advanced, unresectable non-small cell lung cancer (NSCLC), it can be associated with substantial pulmonary toxicity in some patients. Current radiotherapy planning techniques aim to minimize the radiation dose to the lungs, without accounting for regional variations in lung function. Many patients, particularly smokers, can have substantial regional differences in pulmonary ventilation patterns, and it has been hypothesized that preferential avoidance of functional lung during radiotherapy may reduce toxicity. Although several investigators have shown that functional lung can be identified using advanced imaging techniques and/or demonstrated the feasibility and theoretical advantages of avoiding functional lung during radiotherapy, to our knowledge this premise has never been tested via a prospective randomized clinical trial. Methods/Design Eligible patients will have Stage III NSCLC with intent to receive concurrent chemoradiotherapy (CRT). Every patient will undergo a pre-treatment functional lung imaging study using hyperpolarized 3He MRI in order to identify the spatial distribution of normally-ventilated lung. Before randomization, two clinically-approved radiotherapy plans will be devised for all patients on trial, termed standard and avoidance. The standard plan will be designed without reference to the functional state of the lung, while the avoidance plan will be optimized such that dose to functional lung is as low as reasonably achievable. Patients will then be randomized in a 1:1 ratio to receive either the standard or the avoidance plan, with both the physician and the patient blinded to the randomization results. This study aims to accrue a total of 64 patients within two years. The primary endpoint will be a pulmonary quality of life (QOL) assessment at 3 months post-treatment, measured using the functional assessment of cancer therapy–lung cancer subscale. Secondary endpoints include: pulmonary QOL at other time-points, provider-reported toxicity, overall survival, progression-free survival, and quality-adjusted survival. Discussion This randomized, double-blind trial will comprehensively assess the impact of functional lung avoidance on pulmonary toxicity and quality of life in patients receiving concurrent CRT for locally advanced NSCLC. Trial registration Clinicaltrials.gov identifier: NCT02002052.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Brian P Yaremko
- Department of Radiation Oncology, London Regional Cancer Program, 790 Commissioners Rd, E, London, Ontario N6A 4L6, Canada.
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Milne S, King GG. Advanced imaging in COPD: insights into pulmonary pathophysiology. J Thorac Dis 2014; 6:1570-85. [PMID: 25478198 DOI: 10.3978/j.issn.2072-1439.2014.11.30] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/10/2014] [Indexed: 12/31/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) involves a complex interaction of structural and functional abnormalities. The two have long been studied in isolation. However, advanced imaging techniques allow us to simultaneously assess pathological processes and their physiological consequences. This review gives a comprehensive account of the various advanced imaging modalities used to study COPD, including computed tomography (CT), magnetic resonance imaging (MRI), and the nuclear medicine techniques positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Some more recent developments in imaging technology, including micro-CT, synchrotron imaging, optical coherence tomography (OCT) and electrical impedance tomography (EIT), are also described. The authors identify the pathophysiological insights gained from these techniques, and speculate on the future role of advanced imaging in both clinical and research settings.
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Affiliation(s)
- Stephen Milne
- 1 The Woolcock Institute of Medical Research, Glebe, Sydney NSW 2037, Australia ; 2 Northern Clinical School, University of Sydney, NSW 2006, Australia ; 3 Northern and Central Clinical Schools, University of Sydney, NSW 2006, Australia ; 4 Department of Respiratory Medicine, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
| | - Gregory G King
- 1 The Woolcock Institute of Medical Research, Glebe, Sydney NSW 2037, Australia ; 2 Northern Clinical School, University of Sydney, NSW 2006, Australia ; 3 Northern and Central Clinical Schools, University of Sydney, NSW 2006, Australia ; 4 Department of Respiratory Medicine, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
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Bajc M, Markstad H, Jarenbäck L, Tufvesson E, Bjermer L, Jögi J. Grading obstructive lung disease using tomographic pulmonary scintigraphy in patients with chronic obstructive pulmonary disease (COPD) and long-term smokers. Ann Nucl Med 2014; 29:91-9. [PMID: 25315109 PMCID: PMC4284371 DOI: 10.1007/s12149-014-0913-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/30/2014] [Indexed: 01/08/2023]
Abstract
UNLABELLED The severity of chronic obstructive lung disease (COPD) is defined by the degree of flow limitation measured as forced expiratory volume in 1 s, which mainly reflects impairment of large and intermediate airways. However, COPD is primarily a small airways disease. Therefore, better diagnostic tools are needed. Ventilation-Perfusion (V/P) SPECT is a sensitive method to detect obstructive lung changes but criteria for staging airway obstruction are missing. PURPOSE To define and validate criteria to stage COPD using V/P SPECT. METHOD 74 subjects (healthy non-smokers, healthy smokers or with stable COPD) were included. All were examined with V/P SPECT in a hybrid SPECT/CT system. Spirometry was performed and patients were evaluated with the clinical COPD questionnaire (CCQ). V/P SPECT was interpreted independently. Preserved lung function (%) was evaluated. The degree of airway obstruction on V/P SPECT was graded according to newly-developed grading criteria. The degree of airway obstruction was graded from normal (0) to severe (3). The airway obstructivity-grade and degree of preserved lung function were compared to GOLD, CCQ and LDCT emphysema extent. RESULTS Obstructivity-grade (r = 0.66, P < 0.001) and the degree of preserved lung function (r = -0.70, P < 0.001) both correlated to GOLD. Total preserved lung function decreased in relation to higher GOLD stage. There was a significant difference between healthy controls and apparently healthy long time smokers both regarding obstructivity-grade (P = 0.001) and preserved lung function (P < 0.001). Long-time smokers did not differ significantly from GOLD 1 COPD patients (P = 0.14 and P = 0.55 for obstructivity-grade and preserved lung function, respectively). However, patients in GOLD 1 differed in obstructivity-grade from non-smoking controls (P = 0.02). CONCLUSION Functional imaging with V/P SPECT enables standardized grading of airway obstruction as well as reduced lung function, both of which correlate with GOLD stage. V/P SPECT shows that long-term smokers in most cases have signs of ventilatory impairment and airway obstruction not shown by spirometry.
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Affiliation(s)
- Marika Bajc
- Department of Clinical Physiology and Nuclear Medicine, Department of Imaging and Physiology, Skåne University Hospital and Lund University, 22185, Lund, Sweden,
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Siva S, Callahan J, Kron T, Martin OA, MacManus MP, Ball DL, Hicks RJ, Hofman MS. A prospective observational study of Gallium-68 ventilation and perfusion PET/CT during and after radiotherapy in patients with non-small cell lung cancer. BMC Cancer 2014; 14:740. [PMID: 25277150 PMCID: PMC4192760 DOI: 10.1186/1471-2407-14-740] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 09/25/2014] [Indexed: 12/25/2022] Open
Abstract
Background Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancers, and is the leading cause of cancer deaths. Radiation therapy (RT), alone or in combination with chemotherapy, is the standard of care for curative intent treatment of patients with locally advanced or inoperable NSCLC. The ability to intensify treatment to achieve a better chance for cure is limited by the risk of injury to the surrounding lung. Methods/Design This is a prospective observational study of 60 patients with NSCLC receiving curative intent RT. Independent human ethics board approval was received from the Peter MacCallum Cancer Centre ethics committee. In this research, Galligas and Gallium-68 macroaggregated albumin (MAA) positron emission tomography (PET) imaging will be used to measure ventilation (V) and perfusion (Q) in the lungs. This is combined with computed tomography (CT) and both performed with a four dimensional (4D) technique that tracks respiratory motion. This state-of-the-art scan has superior resolution, accuracy and quantitative ability than previous techniques. The primary objective of this research is to observe changes in ventilation and perfusion secondary to RT as measured by 4D V/Q PET/CT. Additionally, we plan to model personalised RT plans based on an individual’s lung capacity. Increasing radiation delivery through areas of poorly functioning lung may enable delivery of larger, more effective doses to tumours without increasing toxicity. By performing a second 4D V/Q PET/CT scan during treatment, we plan to simulate biologically adapted RT depending on the individual’s accumulated radiation injury. Tertiary aims of the study are assess the prognostic significance of a novel combination of clinical, imaging and serum biomarkers in predicting for the risk of lung toxicity. These biomarkers include spirometry, 18 F-Fluorodeoxyglucose PET/CT, gamma-H2AX signals in hair and lymphocytes, as well as assessment of blood cytokines. Discussion By correlating these biomarkers to toxicity outcomes, we aim to identify those patients early who will not tolerate RT intensification during treatment. This research is an essential step leading towards the design of future biologically adapted radiotherapy strategies to mitigate the risk of lung injury during dose escalation for patients with locally advanced lung cancer. Trials registration Universal Trial Number (UTN) U1111-1138-4421.
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Affiliation(s)
- Shankar Siva
- Division of Radiation Oncology and Cancer Imaging, St Andrews Place, East Melbourne 3002, Australia.
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Lung scintigraphy in the diagnosis of pulmonary embolism: current methods and interpretation criteria in clinical practice. Radiol Oncol 2014; 48:113-9. [PMID: 24991200 PMCID: PMC4078029 DOI: 10.2478/raon-2013-0060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 08/18/2013] [Indexed: 11/25/2022] Open
Abstract
Background In current clinical practice lung scintigraphy is mainly used to exclude pulmonary embolism (PE). Modified diagnostic criteria for planar lung scintigraphy are considered, as newer scitigraphic methods, especially single photon emission computed tomography (SPECT) are becoming more popular. Patients and methods. Data of 98 outpatients who underwent planar ventilation/perfusion (V/Q) scintigraphy and 49 outpatients who underwent V/Q SPECT from the emergency department (ED) were retrospectively collected. Planar V/Q images were interpreted according to 0.5 segment mismatch criteria and revised PIOPED II criteria and perfusion scans according to PISA-PED criteria. V/Q SPECT images were interpreted according to the criteria suggested in EANM guidelines. Final diagnosis of PE was based on the clinical decision of an attending physician and evaluation of a 12 months follow-up period. Results Using 0.5 segment mismatch criteria and revised PIOPED II, planar V/Q scans were diagnostic in 93% and 84% of cases, respectively. Among the diagnostic planar scans readings specificity for 0.5 segment mismatch criteria was 98%, and 99% for revised PIOPED II criteria. V/Q SPECT showed a sensitivity of 100% and a specificity of 98%, without any non-diagnostic cases. In patients with low pretest probability for PE, planar V/Q scans assessed by 0.5 segment mismatch criteria were diagnostic in 92%, and in 85% using revised PIOPED II criteria, while perfusion scintigraphy without ventilation scans was diagnostic in 80%. Conclusions Lung scintigraphy yielded diagnostically definitive results and is reliable in ruling out PE in patients from ED. V/Q SPECT has excellent specificity and sensitivity without any non-diagnostic results. Percentage of non-diagnostic results in planar lung scintigraphy is considerably smaller when 0.5 segment mismatch criteria instead of revised PIOPED II criteria are used. Diagnostic value of perfusion scintigraphy according to PISA-PED criteria is inferior to combined V/Q scintigraphy; the difference is evident especially in patients with low pretest probability for PE.
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High-resolution imaging of pulmonary ventilation and perfusion with 68Ga-VQ respiratory gated (4-D) PET/CT. Eur J Nucl Med Mol Imaging 2013; 41:343-9. [DOI: 10.1007/s00259-013-2607-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/04/2013] [Indexed: 11/25/2022]
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Abstract
Planar ventilation-perfusion (V/Q) scanning is often used to investigate pulmonary embolism; however, it has well-recognized limitations. SPECT overcomes many of these through its ability to generate 3-dimensional imaging data. V/Q SPECT has higher sensitivity, specificity, and accuracy than planar imaging and a lower indeterminate rate. SPECT allows for new ways to display and analyze data, such as parametric V/Q ratio images. Compared with CT pulmonary angiography, SPECT has higher sensitivity, a lower radiation dose, fewer technically suboptimal studies, and no contrast-related complications. Any nuclear medicine department equipped with a modern hybrid scanner can now perform combined V/Q SPECT with CT (using low-dose protocols) to further enhance diagnostic accuracy. V/Q SPECT (with or without CT) has application in other pulmonary conditions and in research.
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Affiliation(s)
- Paul J Roach
- Department of Nuclear Medicine, Royal North Shore Hospital, and Sydney Medical School, University of Sydney, Sydney, Australia.
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Introduction to 4D Motion Modeling and 4D Radiotherapy. 4D MODELING AND ESTIMATION OF RESPIRATORY MOTION FOR RADIATION THERAPY 2013. [DOI: 10.1007/978-3-642-36441-9_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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