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Wada N, Tsunomori A, Kubo T, Hino T, Hata A, Yamada Y, Ueyama M, Nishino M, Kurosaki A, Ishigami K, Kudoh S, Hatabu H. Assessment of pulmonary function in COPD patients using dynamic digital radiography: A novel approach utilizing lung signal intensity changes during forced breathing. Eur J Radiol Open 2024; 13:100579. [PMID: 39041056 PMCID: PMC11260941 DOI: 10.1016/j.ejro.2024.100579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/23/2024] [Accepted: 06/10/2024] [Indexed: 07/24/2024] Open
Abstract
Objectives To investigate the association of lung signal intensity changes during forced breathing using dynamic digital radiography (DDR) with pulmonary function and disease severity in patients with chronic obstructive pulmonary disease (COPD). Methods This retrospective study included 46 healthy subjects and 33 COPD patients who underwent posteroanterior chest DDR examination. We collected raw signal intensity and gray-scale image data. The lung contour was extracted on the gray-scale images using our previously developed automated lung field tracking system and calculated the average of signal intensity values within the extracted lung contour on gray-scale images. Lung signal intensity changes were quantified as SImax/SImin, representing the maximum ratio of the average signal intensity in the inspiratory phase to that in the expiratory phase. We investigated the correlation between SImax/SImin and pulmonary function parameters, and differences in SImax/SImin by disease severity. Results SImax/SImin showed the highest correlation with VC (rs = 0.54, P < 0.0001), followed by FEV1 (rs = 0.44, P < 0.0001), both of which are key indicators of COPD pathophysiology. In a multivariate linear regression analysis adjusted for confounding factors, SImax/SImin was significantly lower in the severe COPD group compared to the normal group (P = 0.0004) and mild COPD group (P=0.0022), suggesting its potential usefulness in assessing COPD severity. Conclusion This study suggests that the signal intensity changes of lung fields during forced breathing using DDR reflect the pathophysiology of COPD and can be a useful index in assessing pulmonary function in COPD patients, potentially improving COPD diagnosis and management.
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Affiliation(s)
- Noriaki Wada
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
| | - Akinori Tsunomori
- R&D Promotion Division, Healthcare Business Headquarters, KONICA MINOLTA, INC., 2970 Ishikawa-machi, Hachioji-shi, Tokyo 192-8505, Japan
| | - Takeshi Kubo
- Department of Radiology, Tenri Hospital, 200 Mishimacho, Tenri, Nara 632-8552, Japan
| | - Takuya Hino
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Akinori Hata
- Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoshitake Yamada
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masako Ueyama
- Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan
| | - Mizuki Nishino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
| | - Atsuko Kurosaki
- Department of Diagnostic Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan
| | - Kousei Ishigami
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Shoji Kudoh
- Department of Respiratory Medicine, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan
| | - Hiroto Hatabu
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
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Ikari J, Katsumata M, Urano A, Imamoto T, Suzuki Y, Nishiyama A, Yokota H, Ono K, Okamoto K, Abe E, Kamata T, Fujii S, Okumura K, Ota J, Suzuki E, Kawata N, Ozawa Y, Masuda Y, Matsushita K, Sakao S, Uno T, Tatsumi K, Suzuki T. Dynamic chest radiographic evaluation of the effects of tiotropium/olodaterol combination therapy in chronic obstructive pulmonary disease: the EMBODY study protocol for an open-label, prospective, single-centre, non-controlled, comparative study. BMJ Open Respir Res 2024; 11:e002374. [PMID: 39107000 PMCID: PMC11337696 DOI: 10.1136/bmjresp-2024-002374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 07/08/2024] [Indexed: 08/09/2024] Open
Abstract
INTRODUCTION To date, there is limited evidence on the effects of bronchodilators on respiratory dynamics in chronic obstructive pulmonary disease (COPD). Dynamic chest radiography (DCR) is a novel radiographic modality that provides real-time, objective and quantifiable kinetic data, including changes in the lung area (Rs), tracheal diameter, diaphragmatic kinetics and pulmonary ventilation during respiration, at a lower radiation dose than that used by fluoroscopic or CT imaging. However, the therapeutic effect of dual bronchodilators on respiratory kinetics, such as chest wall dynamics and respiratory muscle function, has not yet been prospectively evaluated using DCR. AIM This study aims to evaluate the effects of bronchodilator therapy on respiratory kinetics in patients with COPD using DCR. METHODS AND ANALYSIS This is an open-label, prospective, single-centre, non-controlled, comparative study. A total of 35 patients with COPD, aged 40-85 years, with a forced expiratory volume in the first second of 30-80%, will be enrolled. After a 2-4 weeks washout period, patients will receive tiotropium/olodaterol therapy for 6 weeks. Treatment effects will be evaluated based on DCR findings, pulmonary function test results and patient-related outcomes obtained before and after treatment. The primary endpoint is the change in Rs after therapy. The secondary endpoints include differences in other DCR parameters (diaphragmatic kinetics, tracheal diameter change and maximum pixel value change rate), pulmonary function test results and patient-related outcomes between pre-therapy and post-therapy values. All adverse events will be reported. ETHICS AND DISSEMINATION Ethical approval for this study was obtained from the Ethics Committee of Chiba University Hospital. The results of this trial will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER jRCTs032210543.
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Affiliation(s)
- Jun Ikari
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Megumi Katsumata
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Akira Urano
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Takuro Imamoto
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Yuri Suzuki
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Akira Nishiyama
- Department of Radiology, Tsudanuma Central General Hospital, Narashino, Chiba, Japan
| | - Hajime Yokota
- Department of Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Kojiro Ono
- Medical Imaging R&D Center, Healthcare Business Headquarters, Konica Minolta Inc, Chiyoda-ku, Tokyo, Japan
| | - Kentaro Okamoto
- Medical Imaging R&D Center, Healthcare Business Headquarters, Konica Minolta Inc, Chiyoda-ku, Tokyo, Japan
| | - Eriko Abe
- Division of laboratory medicine, Chiba University Hospital, Chiba, Chiba, Japan
| | - Tomoko Kamata
- Division of laboratory medicine, Chiba University Hospital, Chiba, Chiba, Japan
| | - Shota Fujii
- Department of Radiology, Chiba University Hospital, Chiba, Chiba, Japan
| | - Kenichiro Okumura
- Department of Radiology, Chiba University Hospital, Chiba, Chiba, Japan
| | - Joji Ota
- Department of Radiology, Chiba University Hospital, Chiba, Chiba, Japan
| | - Eiko Suzuki
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Naoko Kawata
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Yoshihito Ozawa
- Biostatistics Section, Clinical Research Center, Chiba University Hospital, Chiba, Chiba, Japan
| | - Yoshitada Masuda
- Department of Radiology, Chiba University Hospital, Chiba, Chiba, Japan
| | - Kazuyuki Matsushita
- Division of laboratory medicine, Chiba University Hospital, Chiba, Chiba, Japan
| | - Seiichiro Sakao
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
- Department of Respiratory Medicine, international university of health and welfare, Narita, Chiba, Japan
| | - Takashi Uno
- Department of Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Koichiro Tatsumi
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
| | - Takuji Suzuki
- Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Chiba, Japan
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Yamaguchi S, Tanaka R, Matsumoto I, Ohkura N, Segars WP, Abadi E, Samei E. Estimation of threshold thickness of residual normal tissue in lung dysfunction detectable by dynamic chest radiography: A virtual imaging trial. Med Phys 2024. [PMID: 38923538 DOI: 10.1002/mp.17271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Dynamic chest radiography (DCR) is a recently developed functional x-ray imaging technique that detects pulmonary ventilation impairment as a decrease in changes in lung density during respiration. However, the diagnostic performance of DCR is uncertain owing to an insufficient number of clinical cases. One solution is virtual imaging trials (VITs), which is an emerging alternative method for efficiently evaluating medical imaging technology via computer simulation techniques. PURPOSE This study aimed to estimate the typical threshold thickness of residual normal tissue below which the presence of emphysema may be detected by DCR via VITs using virtual patients with different physiques and a user-defined ground truth. METHODS Twenty extended cardiac-torso (XCAT) phantoms that exhibited changes in lung density during respiration were generated to simulate virtual patients. To simulate a locally collapsed lung, an air sphere was inserted into each lung regions in the phantom. The XCAT phantom was virtually projected using an x-ray simulator. The respiratory changes in pixel value (ΔPV) were measured on the projected air spheres (simulated lesions) to calculate the percentage of decrease (ΔPV%) relative to ΔPVexp-ins in the absence of an air sphere. The relationship between the amount of residual normal tissue and ΔPV% was fitted to a cubic approximation curve (hereafter, performance curve), and the threshold at which the ΔPV% began to decrease (normal-tissuethre) was determined. The goodness of fit for each performance curve was evaluated according to the coefficient of determination (R2) and the 95% confidence interval derived from the standard errors between the measured and theoretical values corresponding to each performance curve. The ΔPV% was also visualized as a color scaling to validate the results of the VITs in both virtual and clinical patients. RESULTS For each lung region in all body sizes, the ΔPV% decreased as the amount of residual normal tissue decreased and could be defined as a function of the amount of residual normal tissue in front of and behind the simulated lesions with high R2 values. Meanwhile, the difference between the measured and theoretical values corresponding to each performance curve was only partially included in the 95% confidence interval. The normal-tissuethre values were 146.0, 179.5, and 170.9 mm for the upper, middle, and lower lungs, respectively, which were demonstrated in virtual patients and one real patient, where the value of the residual normal tissue was less than that of normal-tissuethre; any reduction in the residual normal tissue was reflected as a reduced ΔPV and depicted as a reduced color intensity. CONCLUSIONS The performance of DCR-based pulmonary impairment assessment depends on the amount of residual normal tissue in front of and behind the lesion rather than on the lesion size. The performance curve can be defined as a function of the amount of residual normal tissue in each lung region with a specific threshold of normal tissue remaining where lesions become detectable, shown as a decrease in ΔPV. The results of VITs are expected to accelerate future clinical trials for DCR-based pulmonary function assessment.
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Affiliation(s)
- Shunya Yamaguchi
- Graduate School of Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Rie Tanaka
- College of Medical, Pharmaceutical & Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Isao Matsumoto
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Noriyuki Ohkura
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
| | - William Paul Segars
- Carl E Ravin Advanced Imaging Labs, Department of Radiology, Duke University, Durham, North Carolina, USA
| | - Ehsan Abadi
- Carl E Ravin Advanced Imaging Labs, Department of Radiology, Duke University, Durham, North Carolina, USA
| | - Ehsan Samei
- Carl E Ravin Advanced Imaging Labs, Department of Radiology, Duke University, Durham, North Carolina, USA
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Cè M, Oliva G, Rabaiotti FL, Macrì L, Zollo S, Aquila A, Cellina M. Portable Dynamic Chest Radiography: Literature Review and Potential Bedside Applications. Med Sci (Basel) 2024; 12:10. [PMID: 38390860 PMCID: PMC10885043 DOI: 10.3390/medsci12010010] [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: 01/06/2024] [Revised: 02/01/2024] [Accepted: 02/03/2024] [Indexed: 02/24/2024] Open
Abstract
Dynamic digital radiography (DDR) is a high-resolution radiographic imaging technique using pulsed X-ray emission to acquire a multiframe cine-loop of the target anatomical area. The first DDR technology was orthostatic chest acquisitions, but new portable equipment that can be positioned at the patient's bedside was recently released, significantly expanding its potential applications, particularly in chest examination. It provides anatomical and functional information on the motion of different anatomical structures, such as the lungs, pleura, rib cage, and trachea. Native images can be further analyzed with dedicated post-processing software to extract quantitative parameters, including diaphragm motility, automatically projected lung area and area changing rate, a colorimetric map of the signal value change related to respiration and motility, and lung perfusion. The dynamic diagnostic information along with the significant advantages of this technique in terms of portability, versatility, and cost-effectiveness represents a potential game changer for radiological diagnosis and monitoring at the patient's bedside. DDR has several applications in daily clinical practice, and in this narrative review, we will focus on chest imaging, which is the main application explored to date in the literature. However, studies are still needed to understand deeply the clinical impact of this method.
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Affiliation(s)
- Maurizio Cè
- Postgraduation School in Radiodiagnostics, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan, Italy; (F.L.R.); (L.M.); (A.A.)
| | - Giancarlo Oliva
- Radiology Department, Fatebenefratelli Hospital, ASST Fatebenefratelli Sacco, 20121 Milan, Italy; (G.O.); (M.C.)
| | - Francesca Lucrezia Rabaiotti
- Postgraduation School in Radiodiagnostics, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan, Italy; (F.L.R.); (L.M.); (A.A.)
| | - Laura Macrì
- Postgraduation School in Radiodiagnostics, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan, Italy; (F.L.R.); (L.M.); (A.A.)
| | - Sharon Zollo
- Konica Minolta Business Solutions Europe GmbH, Capellalaan 65, 2132 JL Hoofddorp, The Netherlands;
| | - Alessandro Aquila
- Postgraduation School in Radiodiagnostics, Università degli Studi di Milano, Via Festa del Perdono 7, 20122 Milan, Italy; (F.L.R.); (L.M.); (A.A.)
| | - Michaela Cellina
- Radiology Department, Fatebenefratelli Hospital, ASST Fatebenefratelli Sacco, 20121 Milan, Italy; (G.O.); (M.C.)
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Yamasaki Y. New Path and Remaining Issues in Clinical Applications of Dynamic Chest Radiography. Circ J 2023; 88:168-169. [PMID: 38057080 DOI: 10.1253/circj.cj-23-0853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Affiliation(s)
- Yuzo Yamasaki
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University
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Fyles F, FitzMaurice TS, Robinson RE, Bedi R, Burhan H, Walshaw MJ. Dynamic chest radiography: a state-of-the-art review. Insights Imaging 2023; 14:107. [PMID: 37332064 DOI: 10.1186/s13244-023-01451-4] [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: 02/15/2023] [Accepted: 05/14/2023] [Indexed: 06/20/2023] Open
Abstract
Dynamic chest radiography (DCR) is a real-time sequential high-resolution digital X-ray imaging system of the thorax in motion over the respiratory cycle, utilising pulsed image exposure and a larger field of view than fluoroscopy coupled with a low radiation dose, where post-acquisition image processing by computer algorithm automatically characterises the motion of thoracic structures. We conducted a systematic review of the literature and found 29 relevant publications describing its use in humans including the assessment of diaphragm and chest wall motion, measurement of pulmonary ventilation and perfusion, and the assessment of airway narrowing. Work is ongoing in several other areas including assessment of diaphragmatic paralysis. We assess the findings, methodology and limitations of DCR, and we discuss the current and future roles of this promising medical imaging technology.Critical relevance statement Dynamic chest radiography provides a wealth of clinical information, but further research is required to identify its clinical niche.
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Affiliation(s)
- Fred Fyles
- Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Thomas S FitzMaurice
- Department of Respiratory Medicine, Liverpool Heart and Chest Hospital NHS Trust, Liverpool, UK.
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK.
| | - Ryan E Robinson
- Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Ram Bedi
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Hassan Burhan
- Respiratory Research Group, Liverpool University Hospitals Foundation Trust, Liverpool, UK
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Martin J Walshaw
- Department of Respiratory Medicine, Liverpool Heart and Chest Hospital NHS Trust, Liverpool, UK
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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FitzMaurice TS, McCann C, Nazareth DS, Walshaw MJ. Characterisation of hemidiaphragm dysfunction using dynamic chest radiography: a pilot study. ERJ Open Res 2021; 8:00343-2021. [PMID: 35211619 PMCID: PMC8862633 DOI: 10.1183/23120541.00343-2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives Dynamic chest radiography (DCR) is a novel real-time digital fluoroscopic imaging system that produces clear, wide field-of-view diagnostic images of the thorax and diaphragm in motion, alongside novel metrics on moving structures within the thoracic cavity. We describe the use of DCR in the measurement of diaphragm motion in a pilot series of cases of suspected diaphragm dysfunction. Methods We studied 21 patients referred for assessment of diaphragm function due to suspicious clinical symptoms or imaging (breathlessness, orthopnoea, reduced exercise tolerance and/or an elevated hemidiaphragm on plain chest radiograph). All underwent DCR with voluntary sniff manoeuvres. Results Paradoxical motion on sniffing was observed in 14 patients, and confirmed in six who also underwent fluoroscopy or ultrasound. In four patients, DCR showed reduced hemidiaphragm excursion, but no paradoxical motion; in three, normal bilateral diaphragm motion was demonstrated. DCR was quick to perform, and well tolerated in all cases and with no adverse events reported. DCR was achieved in ∼5 min per patient, with images available to view by the clinician immediately within the clinical setting. Conclusion DCR is a rapid, well-tolerated and straightforward chest radiography technique that warrants further investigation in the assessment of diaphragm dysfunction. Dynamic chest radiography is a rapid, well-tolerated and straightforward chest radiography technique that warrants further investigation in the assessment of diaphragm dysfunctionhttps://bit.ly/3HFriWk
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Tanaka R, Kasahara K, Ohkura N, Matsumoto I, Tamura M, Takata M, Inoue D, Izumozaki A, Horii J, Matsuura Y, Sanada S. [Paradigm Shift in Respiratory Diagnosis: Current Status and Future Prospects of Dynamic Chest Radiography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:1279-1287. [PMID: 34803108 DOI: 10.6009/jjrt.2021_jsrt_77.11.1279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dynamic chest radiography (DCR) is a flat-panel detector (FPD) -based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view of FPDs permits real-time observation of motion/kinetic findings on the entire lungs, right and left diaphragm, ribs, and chest wall; heart wall motions; respiratory changes in lung density; and diameter of the intrathoracic trachea. Since the dynamic FPDs had been developed in the early 2000s, we focused on the potential of dynamic FPDs for functional X-ray imaging and have launched a research project for the development of an imaging protocol and digital image-processing techniques for the DCR. The quantitative analysis of motion/kinetic findings is helpful for a better understanding of pulmonary function, because the interpretation of dynamic chest radiographs is challenging and time-consuming for radiologists, pulmonologists, and surgeons. Recent clinical studies have demonstrated the usefulness of DCR combined with the digital image processing techniques for the evaluation of pulmonary function and circulation. Especially, there is a major concern in color-mapping images based on dynamic changes in radiographic lung density, where pulmonary impairments can be detected as color defects, even without the use of contrast media or radioactive medicine. Dynamic chest radiography is now commercially available for the use in general X-ray room and therefore can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. This review article describes the current status and future prospects of DCR, which might bring a paradigm shift in respiratory diagnosis.
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Affiliation(s)
- Rie Tanaka
- College of Medical, Pharmaceutical & Health Sciences, Kanazawa University
| | - Kazuo Kasahara
- Department of Respiratory Medicine, Kanazawa University Hospital
| | - Noriyuki Ohkura
- Department of Respiratory Medicine, Kanazawa University Hospital
| | | | | | | | - Dai Inoue
- Department of Radiology, Kanazawa University Hospital
| | | | - Junsei Horii
- Division of Radiology, Kanazawa University Hospital
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Tanaka R, Matsumoto I, Tamura M, Takata M, Yoshida S, Saito D, Tanaka Y, Inoue D, Ohkura N, Kasahara K. Dynamic chest radiography: clinical validation of ventilation and perfusion metrics derived from changes in radiographic lung density compared to nuclear medicine imaging. Quant Imaging Med Surg 2021; 11:4016-4027. [PMID: 34476186 DOI: 10.21037/qims-20-1217] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 04/08/2021] [Indexed: 01/04/2023]
Abstract
Background Dynamic chest radiography (DCR) is a type of non-contrast-enhanced functional lung imaging with a dynamic flat-panel detector (FPD). This study aimed to assess the clinical significance of ventilation and perfusion metrics derived from changes in radiographic lung density on DCR in comparison to nuclear medicine imaging-derived metrics. Methods DCR images of 42 lung cancer patients were sequentially obtained during respiration using a dynamic FPD imaging system. For each subdivided lung region, the maximum change in the averaged pixel value (Δmax), i.e., lung density, due to respiration and cardiac function was calculated, and the percentage of Δmax relative to the total of all lung regions (Δmax%) was computed for ventilation and perfusion, respectively. The Δmax% was compared to the accumulation of radioactive agents such as Tc-99m gas and Tc-99m macro-aggregated albumin (radioactive agents%) on ventilation and perfusion scans in the subdivided lung regions, by Spearman's correlation coefficient (r) and the Dice similarity coefficients (DSC). To facilitate visual evaluation, Δmax% was visualized as a color scaling, where larger Δmax values were indicated by higher color intensities. Results We found a moderate correlation between Δmax% and radioactive agents% on ventilation and perfusion scans, with perfusion metrics (r=0.57, P<0.001) showing a higher correlation than ventilation metrics (r=0.53, P<0.001). We also found a good or strong correlation (r≥0.5) in 80.9% (34/42) of patients for perfusion metrics (r=0.60±0.16) and in 52.4% (22/42) of patients for ventilation metrics (r=0.53±0.16). DSC indicated a moderate correlation for both metrics. Decreased pulmonary function was observed in the form of reduced color intensities on color-mapping images. Conclusions DCR-derived ventilation and perfusion metrics correlated reasonably well with nuclear medicine imaging findings in lung subdivisions, suggesting that DCR could provide useful information on pulmonary function without the use of radioactive contrast agents.
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Affiliation(s)
- Rie Tanaka
- College of Medical, Pharmaceutical & Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Isao Matsumoto
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Masaya Tamura
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Munehisa Takata
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Shuhei Yoshida
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Daisuke Saito
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yusuke Tanaka
- Department of Thoracic Surgery, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Dai Inoue
- Department of Radiology, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
| | - Noriyuki Ohkura
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
| | - Kazuo Kasahara
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
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Katsume Y, Miwa Y, Ueda A, Soejima K. Underdiagnosis of phrenic nerve palsy caused by cryoballoon ablation for atrial fibrillation with upright position chest radiography: usefulness of supine position dynamic chest radiography. Europace 2021; 23:1567. [PMID: 34352087 DOI: 10.1093/europace/euab173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yumi Katsume
- Department of Cardiovascular Medicine, Kyorin University Hospital, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
| | - Yosuke Miwa
- Department of Cardiovascular Medicine, Kyorin University Hospital, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
| | - Akiko Ueda
- Department of Cardiovascular Medicine, Kyorin University Hospital, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
| | - Kyoko Soejima
- Department of Cardiovascular Medicine, Kyorin University Hospital, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan
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Ohkura N, Tanaka R, Watanabe S, Hara J, Abo M, Nakade Y, Horii J, Matsuura Y, Inoue D, Takata M, Tamura M, Matsumoto I, Sanada S, Kasahara K. Chest Dynamic-Ventilatory Digital Radiography in Chronic Obstructive or Restrictive Lung Disease. Int J Chron Obstruct Pulmon Dis 2021; 16:1393-1399. [PMID: 34040366 PMCID: PMC8140888 DOI: 10.2147/copd.s309960] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/04/2021] [Indexed: 12/04/2022] Open
Abstract
Objective The aim of this study was to identify the relationships between parameters obtained from dynamic-ventilatory digital radiography (DR) and ventilatory disorders. Methods This study comprised 273 participants with respiratory diseases who underwent spirometry and functional residual capacity measurements (104 with normal findings on spirometry as controls, 139 with an obstructive lung disorder, 30 with a restrictive lung disorder) were assessed by dynamic-ventilatory DR. Sequential chest radiography images of the patient’s slow and maximum breathing were captured at 15 frames per second by a dynamic flat-panel imaging system. The system measured the following parameters: lung area at maximum inspiration divided by height (lung area_in/height), changes in tracheal diameter due to respiratory motions, rate of tracheal narrowing, diaphragmatic motion, and rate of change in lung area due to respiratory motion. Relationships between these parameters and ventilatory disorders were analyzed. Results Lung area_in/height in patients with restrictive disorders showed significant decreases. Tracheal diameter change and tracheal narrowing rate in patients with obstructive disorders were significantly increased compared to both the control participants and patients with restrictive disorders. Patients with obstructive disorders and patients with restrictive disorders showed decreased diaphragmatic motion and lung area change rate. With the restrictive disorders as references, the area under the curve (AUC), sensitivity and specificity of lung area_in/height were 0.88, 0.77, and 0.88, respectively. With the obstructive disorders as references, the AUC, sensitivity and specificity of tracheal narrowing rate were 0.67, 0.53 and 0.81, respectively. Conclusion Dynamic-ventilatory DR shows potential as a method for the detection and evaluation of ventilatory disorders in patients with respiratory diseases.
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Affiliation(s)
- Noriyuki Ohkura
- Kanazawa University Hospital, Respiratory Medicine, Ishikawa, Japan
| | - Rie Tanaka
- Kanazawa University, College of Medical, Pharmaceutical & Health Sciences, Ishikawa, Japan
| | - Satoshi Watanabe
- Kanazawa University Hospital, Respiratory Medicine, Ishikawa, Japan
| | - Johsuke Hara
- Kanazawa University Hospital, Respiratory Medicine, Ishikawa, Japan
| | - Miki Abo
- Kanazawa University Hospital, Respiratory Medicine, Ishikawa, Japan
| | - Yusuke Nakade
- Kanazawa University Hospital, Clinical Laboratory, Ishikawa, Japan
| | - Junsei Horii
- Kanazawa University Hospital, Department of Radiology, Ishikawa, Japan
| | - Yukihiro Matsuura
- Kanazawa University Hospital, Department of Radiology, Ishikawa, Japan
| | - Dai Inoue
- Kanazawa University Hospital, Radiology, Ishikawa, Japan
| | - Munehisa Takata
- Kanazawa University, Thoracic, Cardiovascular and General Surgery, Ishikawa, Japan
| | - Masaya Tamura
- Kanazawa University, Thoracic, Cardiovascular and General Surgery, Ishikawa, Japan
| | - Isao Matsumoto
- Kanazawa University, Thoracic, Cardiovascular and General Surgery, Ishikawa, Japan
| | - Shigeru Sanada
- Komatsu University, Faculty of Health Sciences, Ishikawa, Japan
| | - Kazuo Kasahara
- Kanazawa University Hospital, Respiratory Medicine, Ishikawa, Japan
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12
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Miyatake H, Tabata T, Tsujita Y, Fujino K, Tanaka R, Eguchi Y. Detection of Pulmonary Embolism Using a Novel Dynamic Flat-Panel Detector System in Monkeys. Circ J 2021; 85:361-368. [PMID: 33583868 DOI: 10.1253/circj.cj-20-0835] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Recently, dynamic chest radiography (DCR) was developed to evaluate pulmonary function using a flat-panel detector (FPD), which can evaluate blood flow in the pulmonary artery without injection of contrast agents. This study investigated the ability of a FPD to measure physiological changes in blood flow and to detect pulmonary embolism (PE) in monkeys.Methods and Results:DCR was performed in 5 monkeys using a FPD. Regions of interest (ROI) were placed in both lung fields of the image, and maximum changes in pixel value (∆pixel value) in the ROI were measured during 1 electrocardiogram cardiac cycle. Next, a PE model was induced using a Swan-Ganz catheter and additional images were taken. The ∆pixel value of the lungs in normal and PE models were compared in both supine and standing positions. The lung ∆pixel value followed the same cycle as the monkey electrocardiogram. ∆pixel values in the upper lung field decreased in the standing as compared to the supine position. In the PE model, the ∆pixel value decreased in the area of pulmonary blood flow occlusion and increased in the contralateral lung as compared to the normal model (normal model 1.287±0.385, PE model occluded side 0.428±0.128, PE model non-occluded side 1.900±0.431). CONCLUSIONS A FPD could detect postural changes in pulmonary blood flow and its reduction caused by pulmonary artery occlusion in a monkey model.
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Affiliation(s)
- Hidemitsu Miyatake
- Department of Critical and Intensive Care Medicine, Shiga University of Medical Science
| | - Takahisa Tabata
- Department of Critical and Intensive Care Medicine, Shiga University of Medical Science
| | - Yasuyuki Tsujita
- Department of Critical and Intensive Care Medicine, Shiga University of Medical Science
| | - Kazunori Fujino
- Department of Critical and Intensive Care Medicine, Shiga University of Medical Science
| | - Rie Tanaka
- College of Medical, Pharmaceutical & Health Sciences, Kanazawa University
| | - Yutaka Eguchi
- Department of Critical and Intensive Care Medicine, Shiga University of Medical Science
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13
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Hanaoka J, Yoden M, Hayashi K, Shiratori T, Okamoto K, Kaku R, Kawaguchi Y, Ohshio Y, Sonoda A. Dynamic perfusion digital radiography for predicting pulmonary function after lung cancer resection. World J Surg Oncol 2021; 19:43. [PMID: 33563295 PMCID: PMC7874664 DOI: 10.1186/s12957-021-02158-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 01/31/2021] [Indexed: 12/25/2022] Open
Abstract
Background Accurate prediction of postoperative pulmonary function is important for ensuring the safety of patients undergoing radical resection for lung cancer. Dynamic perfusion digital radiography is an excellent and easy imaging method for detecting blood flow in the lung compared with the less-convenient conventional lung perfusion scintigraphy. As such, the present study aimed to confirm whether dynamic perfusion digital radiography can be evaluated in comparison with pulmonary perfusion scintigraphy in predicting early postoperative pulmonary function and complications. Methods Dynamic perfusion digital radiography and spirometry were performed before and 1 and 3 months after radical resection for lung cancer. Correlation coefficients between blood flow ratios calculated using dynamic perfusion digital radiography and pulmonary perfusion scintigraphy were then confirmed in the same cases. In all patients who underwent dynamic perfusion digital radiography, the correlation predicted values calculated from the blood flow ratio, and measured values were examined. Furthermore, ppo%FEV1 or ppo%DLco values, which indicated the risk for perioperative complications, were examined. Results A total of 52 participants who satisfied the inclusion criteria were analyzed. Blood flow ratios measured using pulmonary perfusion scintigraphy and dynamic perfusion digital radiography showed excellent correlation and acceptable predictive accuracy. Correlation coefficients between predicted FEV1 values obtained from dynamic perfusion digital radiography or pulmonary perfusion scintigraphy and actual measured values were similar. All patients who underwent dynamic perfusion digital radiography showed excellent correlation between predicted values and those measured using spirometry. A significant difference in ppo%DLco was observed for respiratory complications but not cardiovascular complications. Conclusions Our study demonstrated that dynamic perfusion digital radiography can be a suitable alternative to pulmonary perfusion scintigraphy given its ability for predicting postoperative values and the risk for postoperative respiratory complications. Furthermore, it seemed to be an excellent modality because of its advantages, such as simplicity, low cost, and ease in obtaining in-depth respiratory functional information. Trial registration Registered at UMIN on October 25, 2017. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_his_list.cgi?recptno=R000033957 Registration number: UMIN000029716 Supplementary Information The online version contains supplementary material available at 10.1186/s12957-021-02158-w.
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Affiliation(s)
- Jun Hanaoka
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan.
| | - Makoto Yoden
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Kazuki Hayashi
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Takuya Shiratori
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Keigo Okamoto
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Ryosuke Kaku
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Yo Kawaguchi
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Yasuhiko Ohshio
- Division of General Thoracic Surgery, Department of Surgery, Shiga University of Medical Science, Shiga, Japan
| | - Akinaga Sonoda
- Department of Radiology, Shiga University of Medical Science, Shiga, Japan
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Hata A, Yamada Y, Tanaka R, Nishino M, Hida T, Hino T, Ueyama M, Yanagawa M, Kamitani T, Kurosaki A, Sanada S, Jinzaki M, Ishigami K, Tomiyama N, Honda H, Kudoh S, Hatabu H. Dynamic Chest X-Ray Using a Flat-Panel Detector System: Technique and Applications. Korean J Radiol 2020; 22:634-651. [PMID: 33289365 PMCID: PMC8005348 DOI: 10.3348/kjr.2020.1136] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Dynamic X-ray (DXR) is a functional imaging technique that uses sequential images obtained by a flat-panel detector (FPD). This article aims to describe the mechanism of DXR and the analysis methods used as well as review the clinical evidence for its use. DXR analyzes dynamic changes on the basis of X-ray translucency and can be used for analysis of diaphragmatic kinetics, ventilation, and lung perfusion. It offers many advantages such as a high temporal resolution and flexibility in body positioning. Many clinical studies have reported the feasibility of DXR and its characteristic findings in pulmonary diseases. DXR may serve as an alternative to pulmonary function tests in patients requiring contact inhibition, including patients with suspected or confirmed coronavirus disease 2019 or other infectious diseases. Thus, DXR has a great potential to play an important role in the clinical setting. Further investigations are needed to utilize DXR more effectively and to establish it as a valuable diagnostic tool.
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Affiliation(s)
- Akinori Hata
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Yoshitake Yamada
- Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Rie Tanaka
- Department of Radiological Technology, School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa, Japan
| | - Mizuki Nishino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tomoyuki Hida
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takuya Hino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Masako Ueyama
- Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Masahiro Yanagawa
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Atsuko Kurosaki
- Department of Diagnostic Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Shigeru Sanada
- Clinical Engineering, Komatsu University, Ishikawa, Japan
| | - Masahiro Jinzaki
- Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Kousei Ishigami
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Noriyuki Tomiyama
- Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shoji Kudoh
- Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Hiroto Hatabu
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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15
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Hino T, Hata A, Hida T, Yamada Y, Ueyama M, Araki T, Kamitani T, Nishino M, Kurosaki A, Jinzaki M, Ishigami K, Honda H, Hatabu H, Kudoh S. Projected lung areas using dynamic X-ray (DXR). Eur J Radiol Open 2020; 7:100263. [PMID: 32953949 PMCID: PMC7486627 DOI: 10.1016/j.ejro.2020.100263] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 07/31/2020] [Accepted: 08/24/2020] [Indexed: 11/30/2022] Open
Abstract
The right projected lung area (PLA) was significantly larger than left one. PLA had correlation with height, weight, BMI, vital capacity (VC), and forced expiratory volume in one second (FEV1). Multivariate analysis showed that body mass index (BMI), sex and VC were considered independent correlation factors, respectively.
Background Dynamic X-ray (DXR) provides images of multiple phases of breath with less radiation exposure than CT. The exact images at end-inspiratory or end-expiratory phases can be chosen accurately. Purpose To investigate the correlation of the projected lung area (PLA) by dynamic chest X-ray with pulmonary functions. Material and Methods One hundred sixty-two healthy volunteers who received medical check-ups for health screening were included in this study. All subjects underwent DXR in both posteroanterior (PA) and lateral views and pulmonary function tests on the same day. All the volunteers took several tidal breaths before one forced breath as instructed. The outlines of lungs were contoured manually on the workstation with reference to the motion of diaphragm and the graph of pixel values. The PLAs were calculated automatically, and correlations with pulmonary functions and demographic data were analyzed statistically. Results The PLAs have correlation with physical characteristics, including height, weight and BMI, and pulmonary functions such as vital capacity (VC) and forced expiratory volume in one second (FEV1). VC and FEV1 revealed moderate correlation with the PLAs of PA view in forced inspiratory phase (VC: right, r = 0.65; left, r = 0.69. FEV1: right, r = 0.54; left, r = 0.59). Multivariate analysis showed that body mass index (BMI), sex and VC were considered independent correlation factors, respectively. Conclusion PLA showed statistically significant correlation with pulmonary functions. Our results indicate DXR has a possibility to serve as an alternate method for pulmonary function tests in subjects requiring contact inhibition including patients with suspected or confirmed covid-19.
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Key Words
- %FEV1, percent predicted FEV1
- %VC, percent vital capacity
- BMI, body mass index
- COPD, chronic obstructive pulmonary disease
- Chest radiograph
- DXR, dynamic X-ray
- FEV1%, forced expiratory volume percent in one second divided by FVC
- FEV1, forced expiratory volume in one second
- FPD, flat-panel detector
- FVC, forced vital capacity
- Health screening cohort
- IPF, idiopathic pulmonary fibrosis
- PA, posteroanterior
- PFTs, pulmonary function tests
- PLA, projected lung area
- Projected lung area
- Pulmonary function
- TLC, total lung capacity
- TV, tidal volume
- VC, vital capacity
- dynamic X-ray
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Affiliation(s)
- Takuya Hino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA, USA
- Corresponding author at: Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
| | - Akinori Hata
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA, USA
| | - Tomoyuki Hida
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, Japan
| | - Yoshitake Yamada
- Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Masako Ueyama
- Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo, Japan
| | - Tetsuro Araki
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA, USA
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, Japan
| | - Mizuki Nishino
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA, USA
| | - Atsuko Kurosaki
- Department of Diagnostic Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo, Japan
| | - Masahiro Jinzaki
- Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Kousei Ishigami
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka, Japan
| | - Hiroto Hatabu
- Center for Pulmonary Functional Imaging, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA, USA
| | - Shoji Kudoh
- Japan Anti-Tuberculosis Association, 1-3-12 Kanda-Misakicho, Chiyoda-ku, Tokyo, Japan
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Tanaka R, Matsumoto I, Tamura M, Takata M, Kasahara K, Ohkura N, Inoue D, Matsuura Y. Comparison of dynamic flat-panel detector-based chest radiography with nuclear medicine ventilation-perfusion imaging for the evaluation of pulmonary function: A clinical validation study. Med Phys 2020; 47:4800-4809. [PMID: 32687607 DOI: 10.1002/mp.14407] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/07/2020] [Accepted: 07/13/2020] [Indexed: 01/18/2023] Open
Abstract
PURPOSE Dynamic chest radiography (DCR) is a flat-panel detector (FPD)-based functional lung imaging technique capable of measuring temporal changes in radiographic lung density due to ventilation and perfusion. The aim of this study was to determine the diagnostic performance of DCR in the evaluation of pulmonary function based on changes in radiographic lung density compared to nuclear medicine lung scans. METHODS This study included 53 patients with pulmonary disease who underwent DCR and nuclear medicine imaging at our institution. Dynamic chest radiography was conducted using a dynamic FPD system to obtain sequential chest radiographs during one breathing cycle. The maximum change in the average pixel value (Δmax ) was measured, and the percentage ofΔmax in each lung region, calculated relative to the sum of all lung regions (Δmax %), was calculated for each factor (ventilation and perfusion). The Δmax % was compared with the accumulation of radioactive agents (radioactive agents%) on ventilation and perfusion scans in each lung and lung region using correlation coefficients and scatter plots. The ratio of ventilation to perfusion Δmax % was calculated and compared with nuclear medicine ventilation-perfusion (V/Q) findings in terms of sensitivity and specificity for V/Q mismatch in each lung region. RESULTS There was a high correlation between Δmax % and radioactive agents% for each lung (Ventilation: r = 0.81, perfusion: r = 0.87). However, correlation coefficients were lower (0.37 to 0.80) when comparing individual lung regions, with the upper lung regions showing the lowest correlation coefficients. The sensitivity and specificity of DCR for V/Q mismatch were 63.3% (19/30) and 60.1% (173/288), respectively. Motion artifacts occasionally increased Δmax %, resulting in false negatives. CONCLUSIONS Ventilation and perfusion Δmax % correlated reasonably with radioactive agents% on ventilation and perfusion scans. Although the regional correlations were lower and the detection performance for V/Q mismatch was not enough for clinical use at the moment, these results suggest the potential for DCR to be used as a functional imaging modality that can be performed without the use of radioactive contrast agents. Further technical improvement is required for the implementation of DCR-based V/Q studies.
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Affiliation(s)
- Rie Tanaka
- College of Medical, Pharmaceutical & Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa, 920-0942, Japan
| | - Isao Matsumoto
- Department of Thoracic Surgery, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Masaya Tamura
- Department of Thoracic Surgery, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Munehisa Takata
- Department of Thoracic Surgery, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Kazuo Kasahara
- Department of Respiratory Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Noriyuki Ohkura
- Department of Respiratory Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Dai Inoue
- Department of Respiratory Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
| | - Yukihiro Matsuura
- Department of Radiology, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan
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Tamura M, Matsumoto I, Saito D, Yoshida S, Takata M, Takemura H. Case report: uniportal video-assisted thoracoscopic resection of a solitary fibrous tumor preoperatively predicted visceral pleura origin using dynamic chest radiography. J Cardiothorac Surg 2020; 15:166. [PMID: 32641164 PMCID: PMC7346465 DOI: 10.1186/s13019-020-01212-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/29/2020] [Indexed: 11/24/2022] Open
Abstract
Background Dynamic chest radiography (DCR) is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. DCR provides objective and quantifiable information, such as diaphragm movement, pulmonary ventilation and circulation, and is reasonable for detecting tumor invasion or adhesion. Case presentation We present a case of Solitary Fibrous Tumor of Pleura (SFTP), preoperatively predicted visceral pleura origin using Dynamic chest radiography (DCR) and surgically resected through single-access (uniportal) video-assisted thoracoscopic surgery (UVATS). Conclusions UVATS may be a suitable surgical option for pedunculated SFTPs. Dynamic chest radiography provides information, such as tumor invasion or adhesion and helpful for predicting origin of the tumor.
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Affiliation(s)
- Masaya Tamura
- Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University, Takara-machi 13-1, Kanazawa, 920-8640, Japan.
| | - Isao Matsumoto
- Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University, Takara-machi 13-1, Kanazawa, 920-8640, Japan
| | - Daisuke Saito
- Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University, Takara-machi 13-1, Kanazawa, 920-8640, Japan
| | - Shuhei Yoshida
- Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University, Takara-machi 13-1, Kanazawa, 920-8640, Japan
| | - Munehisa Takata
- Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University, Takara-machi 13-1, Kanazawa, 920-8640, Japan
| | - Hirofumi Takemura
- Department of Thoracic, Cardiovascular and General Surgery, Kanazawa University, Takara-machi 13-1, Kanazawa, 920-8640, Japan
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18
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Ohkura N, Kasahara K, Watanabe S, Hara J, Abo M, Sone T, Kimura H, Takata M, Tamura M, Matsumoto I, Nakade Y, Sanada S, Tanaka R. Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping. Respiration 2020; 99:382-388. [PMID: 32348982 DOI: 10.1159/000506881] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/02/2020] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE The aim of this study was to determine the utility of dynamic-ventilatory digital radiography (DR) for pulmonary function assessment in patients with airflow limitation. METHODS One hundred and eighteen patients with airflow limitation (72 patients with lung cancer before surgery, 35 patients with chronic obstructive pulmonary disease [COPD], 6 patients with asthma, and 5 patients with asthma-COPD overlap syndrome) were assessed with dynamic-ventilatory DR. The patients were instructed to inhale and exhale slowly and maximally. Sequential chest X-ray images were captured in 15 frames per second using a dynamic flat-panel imaging system. The relationship between the lung area and the rate of change in the lung area due to respiratory motion with respect to pulmonary function was analyzed. RESULTS The rate of change in the lung area from maximum inspiration to maximum expiration (Rs ratio) was associated with the RV/TLC ratio (r = 0.48, p < 0.01) and the percentage of the predicted FEV1 (r = -0.33, p < 0.01) in patients with airflow limitations. The Rs ratio also decreased in an FEV1-dependent manner. CONCLUSION The rate of change in the lung area due to respiratory motion evaluated with dynamic DR reflects air trapping. Dynamic DR is a potential tool for the comprehensive assessment of pulmonary function in patients with COPD.
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Affiliation(s)
- Noriyuki Ohkura
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan,
| | - Kazuo Kasahara
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan
| | - Satoshi Watanabe
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan
| | - Johsuke Hara
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan
| | - Miki Abo
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan
| | - Takashi Sone
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan
| | - Hideharu Kimura
- Department of Respiratory Medicine, Kanazawa University Hospital, Kanazawa, Japan
| | - Munehisa Takata
- Department of Thoracic, Cardiovascular, and General Surgery, Kanazawa University Hospital, Kanazawa, Japan
| | - Masaya Tamura
- Department of Thoracic, Cardiovascular, and General Surgery, Kanazawa University Hospital, Kanazawa, Japan
| | - Isao Matsumoto
- Department of Thoracic, Cardiovascular, and General Surgery, Kanazawa University Hospital, Kanazawa, Japan
| | - Yusuke Nakade
- Clinical Laboratory, Kanazawa University Hospital, Kanazawa, Japan
| | - Shigeru Sanada
- Faculty of Health Sciences, Komatsu University, Komatsu, Japan
| | - Rie Tanaka
- College of Medical, Pharmaceutical, and Health Sciences, Kanazawa University, Kanazawa, Japan
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19
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Dynamic chest radiography: Novel and less-invasive imaging approach for preoperative assessments of pleural invasion and adhesion. Radiol Case Rep 2020; 15:702-704. [PMID: 32280402 PMCID: PMC7138928 DOI: 10.1016/j.radcr.2020.02.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 11/24/2022] Open
Abstract
Here, we report a case of lung cancer with preoperatively predicted invasion to the parietal pleura on dynamic chest radiography (DCR). An 82-year-old patient was referred for staging of a right lung tumor. Preoperative DCR revealed invasion or adhesion of the tumor to the chest wall, and intraoperative findings revealed invasion of the tumor to the parietal pleura. DCR provides objective and quantifiable information, including diaphragmatic movement, pulmonary ventilation, and circulation, as well as tumor invasion or adhesion and is less invasive compared to 3-dimensional chest computed tomography or cine magnetic resonance imaging. This study was our initial attempt at performing a quantitative assessment using DCR.
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Pulmonary Function Diagnosis Based on Respiratory Changes in Lung Density With Dynamic Flat-Panel Detector Imaging: An Animal-Based Study. Invest Radiol 2019; 53:417-423. [PMID: 29505487 DOI: 10.1097/rli.0000000000000457] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVES The aims of this study were to address the relationship between respiratory changes in image density of the lungs and tidal volume, to compare the changes between affected and unaffected lobes, and to apply this new technique to the diagnosis of atelectasis. MATERIALS AND METHODS Our animal care committee approved this prospective animal study. Sequential chest radiographs of 4 pigs were obtained under respiratory control with a ventilator using a dynamic flat-panel detector system. Porcine models of atelectasis were developed, and the correlation between the tidal volume and changes in pixel values measured in the lungs were analyzed. The mean difference in respiratory changes in pixel values between both lungs was tested using paired t tests. To facilitate visual evaluation, respiratory changes in pixel values were visualized in the form of a color display, that is, as changes in color scale. RESULTS Average pixel values in the lung regions changed according to forced respiration. High linearity was observed between changes in pixel values and tidal volume in the normal models (r = 0.99). Areas of atelectasis displayed significantly reduced changes in pixel values (P < 0.05). Of all atelectasis models with air trapping and air inflow restriction, 92.7% (19/20) were visualized as color-defective or color-marked areas on functional images, respectively. CONCLUSION Dynamic chest radiography allows for the relative evaluation of tidal volume, the detection of ventilation defects in the lobe unit, and a differential diagnosis between air trapping and air inflow restriction, based on respiratory changes in image density of the lungs, even without the use of contrast media.
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Time-resolved quantitative evaluation of diaphragmatic motion during forced breathing in a health screening cohort in a standing position: Dynamic chest phrenicography. Eur J Radiol 2019; 113:59-65. [DOI: 10.1016/j.ejrad.2019.01.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/21/2019] [Accepted: 01/30/2019] [Indexed: 11/18/2022]
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Hida T, Yamada Y, Ueyama M, Araki T, Nishino M, Kurosaki A, Jinzaki M, Honda H, Hatabu H, Kudoh S. Decreased and slower diaphragmatic motion during forced breathing in severe COPD patients: Time-resolved quantitative analysis using dynamic chest radiography with a flat panel detector system. Eur J Radiol 2019; 112:28-36. [PMID: 30777216 DOI: 10.1016/j.ejrad.2018.12.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 12/17/2018] [Accepted: 12/30/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To assess the diaphragmatic motion in chronic obstructive pulmonary disease (COPD) patients during forced breathing by time-resolved quantitative analysis using dynamic chest radiography and to demonstrate the characteristics and the difference from that in normal subjects. MATERIALS AND METHODS Thirty-one COPD patients and a matched control of 31 normal subjects on age, sex, height, and weight, who underwent chest radiographs during forced breathing using dynamic chest radiography, were included in this study. COPD patients were classified based on the criteria of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) (GOLD 1, n = 3; GOLD 2, n = 12; GOLD 3, n = 13; GOLD 4, n = 3). We measured excursions and peak motion speeds of the diaphragms for each participant. We compared the results among GOLD 1/2, GOLD 3/4 groups and normal subjects and investigated associations between the data, and participants' demographics, or pulmonary function. RESULTS The excursions of bilateral diaphragms were significantly decreased in the GOLD 3/4 group relative to normal subjects (right, 39.8 ± 15.3 mm vs. 52.7 ± 15.1 mm, P = 0.030; left, 43.7 ± 14.0 mm vs. 56.9 ± 15.5 mm, P = 0.017; mean ± standard deviation) and the GOLD 1/2 group (right, 39.8 ± 15.3 mm vs. 54.4 ± 16.7 mm, P = 0.036; left, 43.7 ± 14.0 mm vs. 60.5 ± 13.9 mm, P = 0.008). The peak motion speeds of the left diaphragm in the inspiratory phase were slower in the GOLD 1/2 group than in normal subjects (24.5 ± 8.0 mm/s vs. 33.6 ± 14.0 mm/s, P = 0.038), and in the GOLD 3/4 group than in normal subjects (25.6 ± 6.8 mm/s vs. 33.6 ± 14.0 mm/s, P = 0.067). The excursions of the diaphragms showed correlation with VC, %VC, and FEV1, while the peak motion speeds showed no significant correlation with pulmonary function tests. CONCLUSIONS Time-resolved quantitative analysis of diaphragms with dynamic chest radiography indicated differences in diaphragmatic motion between COPD groups and normal subjects during forced breathing. The excursions of the diaphragms during forced breathing were significantly lower in the GOLD 3/4 group than those in the GOLD 1/2 group and normal subjects.
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Affiliation(s)
- Tomoyuki Hida
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA; Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Yoshitake Yamada
- Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masako Ueyama
- Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan
| | - Tetsuro Araki
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
| | - Mizuki Nishino
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
| | - Atsuko Kurosaki
- Department of Diagnostic Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan
| | - Masahiro Jinzaki
- Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hiroto Hatabu
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA.
| | - Shoji Kudoh
- Department of Respiratory Medicine, Fukujuji Hospital, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8522, Japan
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Yamada Y, Ueyama M, Abe T, Araki T, Abe T, Nishino M, Jinzaki M, Hatabu H, Kudoh S. Time-Resolved Quantitative Analysis of the Diaphragms During Tidal Breathing in a Standing Position Using Dynamic Chest Radiography with a Flat Panel Detector System ("Dynamic X-Ray Phrenicography"): Initial Experience in 172 Volunteers. Acad Radiol 2017; 24:393-400. [PMID: 27989446 DOI: 10.1016/j.acra.2016.11.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/02/2016] [Accepted: 11/02/2016] [Indexed: 11/28/2022]
Abstract
RATIONALE AND OBJECTIVES Diaphragmatic motion in a standing position during tidal breathing remains unclear. The purpose of this observational study was to evaluate diaphragmatic motion during tidal breathing in a standing position in a health screening center cohort using dynamic chest radiography in association with participants' demographic characteristics. MATERIALS AND METHODS One hundred seventy-two subjects (103 men; aged 56.3 ± 9.8 years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions of and peak motion speeds of the diaphragms. Associations between the excursions and participants' demographics (gender, height, weight, body mass index [BMI], smoking history, tidal volume, vital capacity, and forced expiratory volume) were investigated. RESULTS The average excursion of the left diaphragm (14.9 ± 4.6 mm, 95% CI 14.2-15.5 mm) was significantly larger than that of the right (11.0 ± 4.0 mm, 95% CI 10.4-11.6 mm) (P <0.001). The peak motion speed of the left diaphragm (inspiratory, 16.6 ± 4.2 mm/s; expiratory, 13.7 ± 4.2 mm/s) was significantly faster than that of the right (inspiratory, 12.4 ± 4.4 mm/s; expiratory, 9.4 ± 3.8 mm/s) (both P <0.001). Both simple and multiple regression models demonstrated that higher BMI and higher tidal volume were associated with increased excursions of the bilateral diaphragm (all P <0.05). CONCLUSIONS The average excursions of the diaphragms are 11.0 mm (right) and 14.9 mm (left) during tidal breathing in a standing position. The diaphragmatic motion of the left is significantly larger and faster than that of the right. Higher BMI and tidal volume are associated with increased excursions of the bilateral diaphragm.
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Affiliation(s)
- Yoshitake Yamada
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215; Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - Masako Ueyama
- Department of Health Care, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan
| | - Takehiko Abe
- Department of Radiology, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan
| | - Tetsuro Araki
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215
| | - Takayuki Abe
- Department of Preventive Medicine and Public Health, Biostatistics Unit at Clinical and Translational Research Center, Keio University School of Medicine, Tokyo, Japan
| | - Mizuki Nishino
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215
| | - Masahiro Jinzaki
- Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hiroto Hatabu
- Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02215.
| | - Shoji Kudoh
- Department of Respiratory Medicine, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan
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Dynamic chest radiography: flat-panel detector (FPD) based functional X-ray imaging. Radiol Phys Technol 2016; 9:139-53. [PMID: 27294264 DOI: 10.1007/s12194-016-0361-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function. The basic concept was proposed in the 1980s; however, it was not realized until the 2010s because of technical limitations. Dynamic FPDs and advanced digital image processing played a key role for clinical application of dynamic chest radiography. Pulmonary ventilation and circulation can be quantified and visualized for the diagnosis of pulmonary diseases. Dynamic chest radiography can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. Here, we focus on the evaluation of pulmonary ventilation and circulation. This review article describes the basic mechanism of imaging findings according to pulmonary/circulation physiology, followed by imaging procedures, analysis method, and diagnostic performance of dynamic chest radiography.
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Tanaka R, Sanada S, Sakuta K, Kawashima H. Quantitative analysis of rib kinematics based on dynamic chest bone images: preliminary results. J Med Imaging (Bellingham) 2015; 2:024002. [PMID: 26158097 DOI: 10.1117/1.jmi.2.2.024002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/13/2015] [Indexed: 11/14/2022] Open
Abstract
An image-processing technique for separating bones from soft tissue in static chest radiographs has been developed. The present study was performed to evaluate the usefulness of dynamic bone images in quantitative analysis of rib movement. Dynamic chest radiographs of 16 patients were obtained using a dynamic flat-panel detector and processed to create bone images by using commercial software (Clear Read BS, Riverain Technologies). Velocity vectors were measured in local areas on the dynamic images, which formed a map. The velocity maps obtained with bone and original images for scoliosis and normal cases were compared to assess the advantages of bone images. With dynamic bone images, we were able to quantify and distinguish movements of ribs from those of other lung structures accurately. Limited rib movements of scoliosis patients appeared as a reduced rib velocity field, resulting in an asymmetrical distribution of rib movement. Vector maps in all normal cases exhibited left/right symmetric distributions of the velocity field, whereas those in abnormal cases showed asymmetric distributions because of locally limited rib movements. Dynamic bone images were useful for accurate quantitative analysis of rib movements. The present method has a potential for an additional functional examination in chest radiography.
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Affiliation(s)
- Rie Tanaka
- Kanazawa University , College of Medical, Pharmaceutical, and Health Sciences, School of Health Sciences, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan
| | - Shigeru Sanada
- Kanazawa University , College of Medical, Pharmaceutical, and Health Sciences, School of Health Sciences, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan
| | - Keita Sakuta
- Kanazawa University Hospital , Department of Radiology, 13-1 Takara-machi, Kanazawa 920-8641, Japan
| | - Hiroki Kawashima
- Kanazawa University Hospital , Department of Radiology, 13-1 Takara-machi, Kanazawa 920-8641, Japan
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Tanaka R. [State-of-the-Art technology and research topics in digital radiography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2014; 70:1319-29. [PMID: 25410340 DOI: 10.6009/jjrt.2014_jsrt_70.11.1319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kawashima H, Tada K, Suganuma S, Tsuchiya H, Sanada S. Wrist rhythm during wrist joint motion evaluated by dynamic radiography. ACTA ACUST UNITED AC 2014; 19:343-7. [PMID: 25121940 DOI: 10.1142/s0218810414500257] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We hypothesized that wrist joint motion involves a "wrist rhythm" similar to the scapulohumeral rhythm. Therefore, we used a flat-panel detector to evaluate the ratio of radiolunate and capitolunate joint motions during wrist joint motion by dynamic radiography. The subjects were 20 healthy men. Dynamic imaging of the wrist joint was performed during active exercise for a total of ten seconds. In this study, we defined the radiocarpal (RL angle) and midcarpal joint angle (CL angle) as the wrist joint angle in the obtained images and measured the variation of these angles. The average curve was plotted and regression lines calculated from the average curve. The ratio was calculated from the slopes of the regression lines of the RL CL angles. These findings indicated that the ratio of the RL and CL angle motions was approximately 1:4 during palmar flexion and approximately 2:1 during dorsiflexion.
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Affiliation(s)
- Hiroki Kawashima
- Radiology Division, Kanazawa University Hospital, Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
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Wang Z, Xiong YX. Lung sound patterns help to distinguish congestive heart failure, chronic obstructive pulmonary disease, and asthma exacerbations. Acad Emerg Med 2012; 19:79-84. [PMID: 22251194 DOI: 10.1111/j.1553-2712.2011.01255.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
OBJECTIVES Although congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and asthma patients typically present with abnormal auscultatory findings on lung examination, respiratory sounds are not normally subjected to rigorous analysis. The aim of this study was to evaluate in detail the distribution of respiratory sound intensity in CHF, COPD, and asthma patients during acute exacerbation. METHODS Respiratory sounds throughout the respiratory cycle were captured and displayed using an acoustic-based imaging technique. Breath sound distribution was mapped to create a gray-scale sequence of two-dimensional images based on intensity of sound (vibration). Consecutive CHF (n = 22), COPD (n = 19), and asthma (n = 18) patients were imaged at the time of presentation to the emergency department (ED). Twenty healthy subjects were also enrolled as a comparison group. Geographical area of the images and respiratory sound patterns were quantitatively analyzed. RESULTS In healthy volunteers and COPD patients, the median (interquartile range [IQR]) geographical areas of the vibration energy images were similar, at 75.6 (IQR = 6.0) and 75.8 (IQR = 10.8) kilopixels, respectively (p > 0.05). Compared to healthy volunteers and COPD patients, areas for CHF and asthma patients were smaller, at 66.9 (IQR = 9.9) and 53.9 (IQR = 15.6) kilopixels, respectively (p < 0.05). The geographic area ratios between the left and right lungs for healthy volunteers and CHF and COPD patients were 1.0 (IQR = 0.2), 1.0 (IQR = 0.2), and 1.0 (IQR = 0.1), respectively. Compared to healthy volunteers, the geographic area ratio between the left and right lungs for asthma patients was 0.5 (IQR = 0.4; p < 0.05). In healthy volunteers and CHF patients, the ratios of vibration energy values at peak inspiration and expiration (peak I/E ratio) were 4.6 (IQR = 4.4) and 4.7 (IQR = 3.5). In marked contrast, the peak I/E ratios of COPD and asthma patients were 3.4 (= 2.1) and 0.1 (IQR = 0.3; p < 0.05), respectively. CONCLUSIONS The pilot data generated in this study support the concept that relative differences in respiratory sound intensity may be useful in distinguishing acute dyspnea caused by CHF, COPD, or asthma.
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Affiliation(s)
- Zhen Wang
- Department of Emergency Medicine, Beijing Shi-ji-tan Hospital, Capital Medical University, Beijing, China.
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Xu T, Ducote JL, Wong JT, Molloi S. Dynamic dual-energy chest radiography: a potential tool for lung tissue motion monitoring and kinetic study. Phys Med Biol 2011; 56:1191-205. [PMID: 21285477 DOI: 10.1088/0031-9155/56/4/019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dual-energy chest radiography has the potential to provide better diagnosis of lung disease by removing the bone signal from the image. Dynamic dual-energy radiography is now possible with the introduction of digital flat-panel detectors. The purpose of this study is to evaluate the feasibility of using dynamic dual-energy chest radiography for functional lung imaging and tumor motion assessment. The dual-energy system used in this study can acquire up to 15 frames of dual-energy images per second. A swine animal model was mechanically ventilated and imaged using the dual-energy system. Sequences of soft-tissue images were obtained using dual-energy subtraction. Time subtracted soft-tissue images were shown to be able to provide information on regional ventilation. Motion tracking of a lung anatomic feature (a branch of pulmonary artery) was performed based on an image cross-correlation algorithm. The tracking precision was found to be better than 1 mm. An adaptive correlation model was established between the above tracked motion and an external surrogate signal (temperature within the tracheal tube). This model is used to predict lung feature motion using the continuous surrogate signal and low frame rate dual-energy images (0.1-3.0 frames per second). The average RMS error of the prediction was (1.1 ± 0.3) mm. The dynamic dual energy was shown to be potentially useful for lung functional imaging such as regional ventilation and kinetic studies. It can also be used for lung tumor motion assessment and prediction during radiation therapy.
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Affiliation(s)
- Tong Xu
- Department of Physics, Carleton University, Ottawa, ON, Canada.
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Ventilatory impairment detection based on distribution of respiratory-induced changes in pixel values in dynamic chest radiography: a feasibility study. Int J Comput Assist Radiol Surg 2010; 6:103-10. [PMID: 20549376 DOI: 10.1007/s11548-010-0491-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 05/17/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE Decreased ventilation is observed on chest radiographs as small changes in X-ray translucency, and ventilatory impairments can therefore be detected by analyzing the distribution of respiratory-induced changes in pixel value. This study was performed to develop a ventilatory impairment detection method based on the distribution of respiratory-induced changes in pixel values. METHODS Sequential chest radiographs during respiration were obtained using a dynamic flat panel detector system. Respiratory-induced changes in pixel value were measured in each local area and then compared for symmetrical positions in both lungs, which were located at the same distance from the axis of the thorax at the same level. The right-left symmetry was assessed in 20 clinical cases (Abnormal, 14; Normal, 6). RESULTS In normal controls, the distribution was symmetrical, and there were good correlations of the pixel value changes in both lungs at symmetrical positions (r = 0.66 ± 0.05). In contrast, abnormal cases did not show a symmetrical distribution of pixel value changes (r = 0.40 ± 0.23) due to ventilation abnormalities observed as reductions in pixel value changes. CONCLUSIONS Ventilatory impairment could be detected as deviation from the right-left symmetry of respiratory-induced changes in pixel value. In particular, the present method could be useful for detecting unilateral abnormalities. However, to detect bilateral abnormalities, further studies are required to develop multilevel detection methods combined with several methods of pattern analysis.
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Tanaka R, Sanada S, Fujimura M, Yasui M, Tsuji S, Hayashi N, Nanbu Y, Matsui O. [Pulmonary functional diagnostic imaging using a dynamic flat-panel detector: comparison with findings in pulmonary scintigraphy]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2009; 65:728-37. [PMID: 19602797 DOI: 10.6009/jjrt.65.728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pulmonary ventilation and circulation dynamics are reflected on dynamic chest radiographs as changes in X-ray translucency,i.e., pixel values. The present study was performed to develop a pulmonary functional evaluation method based on the changes in pixel value, and to investigate the clinical usefulness of our method. Sequential chest radiographs of 20 subjects (abnormal,n=12; normal,n=8) during respiration were obtained with a dynamic flat-panel detector (FPD) system. The average pixel value in each local area was measured tracking the same area. To facilitate visual evaluation, the results were mapped on the original image using a grayscale in which small changes were shown in black and large changes were shown in white. In our clinical evaluation in comparison with a pulmonary scintigraphy, pulmonary ventilation disorder was indicated as a reduction of changes in pixel values. In many patients, there was a correlation between our result and a pulmonary scintigraphy (0.7<r, 4 cases; 0.4<r<or=0.7, 6 cases; 0.2<r<or=0.4, 1 case; 0<r<or=0.2, 1 case). The present method with real-time computer analysis is expected to be a rapid and simple method for evaluating pulmonary function and as an additional examination in conventional chest radiography.
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Affiliation(s)
- Rie Tanaka
- Department of Radiological Technology, School of Health Sciences, College of Medical, Pharmaceutical and Health Sciences, Kanazawa University
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Tanaka R. [Expectation of new diagnostic imaging with a dynamic flat-panel detector (FPD)]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2009; 65:861-868. [PMID: 19602815 DOI: 10.6009/jjrt.65.861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Kawashima H, Tanaka R, Sanada S. [Reproducibility of dynamic chest radiography with a flat-panel detector - respiratory changes in pixel value]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2009; 65:738-44. [PMID: 19602798 DOI: 10.6009/jjrt.65.738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dynamic chest radiography using a flat panel detector (FPD) with a large field of view is expected to be a useful pulmonary functional evaluation method based on the respiratory changes in pixel value. For clinical use as a follow-up and therapeutic evaluation tool, the system must have a high degree of reproducibility in measurements of pixel values. The present study was performed to investigate the reproducibility of respiratory changes in pixel values. Dynamic chest radiographs of five normal subjects and one patient were obtained. Imaging was performed twice in each subject. The slope (X-ray translucency variation) was then calculated from the changes in pixel value from distance lung apex-diaphragm, and the slopes of two sequences were compared. The results showed there were no significant differences in changes in pixel value between the two sequences in all normal subject (5 males, p>0.05). The results indicated that the present method has reproducibility for measuring pulmonary function and also has potential as a tool for follow-up and therapeutic evaluation.
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Affiliation(s)
- Hiroki Kawashima
- Division of Health Sciences, Radiology, Graduate School of Medical Science, Kanazawa University
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Pulmonary blood flow evaluation using a dynamic flat-panel detector: feasibility study with pulmonary diseases. Int J Comput Assist Radiol Surg 2009; 4:449-55. [PMID: 20033527 DOI: 10.1007/s11548-009-0364-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE Pulmonary ventilation and circulation dynamics are reflected on fluoroscopic images as changes in X-ray translucency. The purpose of this study was to investigate the feasibility of non-contrast functional imaging using a dynamic flat-panel detector (FPD). METHODS Dynamic chest radiographs of 20 subjects (abnormal, n = 12; normal, n = 8) were obtained using the FPD system. Image analysis was performed to get qualitative perfusion mapping image; first, focal pixel value was defined. Second, lung area was determined and pulmonary hilar areas were eliminated. Third, one cardiac cycle was determined in each of the cases. Finally, total changes in pixel values during one cardiac cycle were calculated and their distributions were visualized with mapping on the original image. They were compared with the findings of lung perfusion scintigraphy. RESULTS In all normal controls, the total changes in pixel value in one cardiac cycle decreased from the hilar region to the peripheral region of the lung with left-right symmetric distribution. In contrast, in many abnormal cases, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on a mapping image. The findings of mapping image coincided with those of lung perfusion scintigraphy. CONCLUSIONS Dynamic chest radiography using an FPD system with computer analysis is expected to be a new type of functional imaging, which provides pulmonary blood flow distribution additionally.
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Tanaka R, Sanada S, Okazaki N, Kobayashi T, Suzuki M, Matsui T, Matsui O. Detectability of regional lung ventilation with flat-panel detector-based dynamic radiography. J Digit Imaging 2008; 21:109-20. [PMID: 17356803 PMCID: PMC3043825 DOI: 10.1007/s10278-007-9017-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This study was performed to investigate the ability of breathing chest radiography using flat-panel detector (FPD) to quantify relative local ventilation. Dynamic chest radiographs during respiration were obtained using a modified FPD system. Imaging was performed in three different positions, ie, standing and right and left decubitus positions, to change the distribution of local ventilation. We measured the average pixel value in the local lung area. Subsequently, the interframe differences, as well as difference values between maximum inspiratory and expiratory phases, were calculated. The results were visualized as images in the form of a color display to show more or less x-ray translucency. Temporal changes and spatial distribution of the results were then compared to lung physiology. In the results, the average pixel value in each lung was associated with respiratory phase. In all positions, respiratory changes of pixel value in the lower area were greater than those in the upper area (P < 0.01), which was the same tendency as the regional differences in ventilation determined by respiratory physiology. In addition, in the decubitus position, it was observed that areas with large respiratory changes in pixel value moved up in the vertical direction during expiration, which was considered to be airway closure. In conclusion, breathing chest radiography using FPD was shown to be capable of quantifying relative ventilation in local lung area and detecting regional differences in ventilation and timing of airway closure. This method is expected to be useful as a new diagnostic imaging modality for evaluating relative local ventilation.
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Affiliation(s)
- Rie Tanaka
- Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Japan.
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Wang Z, Bartter T, Baumann BM, Baugmann BM, Baumman BM, Abouzgheib W, Chansky ME, Jean S. Asynchrony between left and right lungs in acute asthma. J Asthma 2008; 45:575-8. [PMID: 18773329 DOI: 10.1080/02770900802017744] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Asthma is a disease of air flow obstruction. Transmitted sounds can be analyzed in detail and may shed light upon the physiology of asthma and how it changes over time. The goals of this study were to use a computerized analytic acoustic tool to evaluate respiratory sound patterns in asthmatic patients during acute attacks and after clinical improvement and to compare asthmatic profiles with those of normal individuals. METHODS Respiratory sound analysis throughout the respiratory cycle was performed on 22 symptomatic asthma patients at the time of presentation to the emergency department (ED) and after clinical improvement. Fifteen healthy volunteers were analyzed as a control group. Vibrations patterns were plotted. Right and left lungs were analyzed separately. RESULTS Asthmatic attacks were found to be correlated with asynchrony between lungs. In normal subjects, the inspiratory and expiratory vibration energy peaks (VEPs) occurred almost simultaneously in both lungs; the time interval between right and left expiratory VEPs was 0.006 +/- 0.012 seconds. In symptomatic asthmatic patients on admission, the time interval between right and left expiratory VEPs was 0.14 +/- 0.09 seconds and after clinical improvement the interval decreased to 0.04 +/- 0.04 seconds. Compared to healthy volunteers, asynchrony between two lungs was increased in asthmatics (p < 0.05). The asynchrony was significantly reduced after clinical improvement (p < 0.05). CONCLUSIONS Respiratory sound analysis demonstrated significant asynchrony between right and left lungs in asthma exacerbations, a finding which, to our knowledge, has never been reported to date. The asynchrony is significantly reduced with clinical improvement following treatment.
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Affiliation(s)
- Zhen Wang
- Department of Emergency Medicine, Third Hospital, Peking University, Beijing, China
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Development of functional chest imaging with a dynamic flat-panel detector (FPD). Radiol Phys Technol 2008; 1:137-43. [PMID: 20821139 DOI: 10.1007/s12194-008-0020-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 03/11/2008] [Accepted: 03/12/2008] [Indexed: 10/22/2022]
Abstract
Dynamic FPD permits the acquisition of distortion-free radiographs with a large field of view and high image quality. In the present study, we investigated the feasibility of functional imaging for evaluating the pulmonary sequential blood distribution with an FPD, based on changes in pixel values during cardiac pumping. Dynamic chest radiographs of seven normal subjects were obtained in the expiratory phase by use of an FPD system. We measured the average pixel value in each region of interest that was located manually in the heart and lung areas. Subsequently, inter-frame differences and differences from a minimum-intensity projection image, which was created from one cardiac cycle, were calculated. These difference values were then superimposed on dynamic chest radiographs in the form of a color display, and sequential blood distribution images and a blood distribution map were created. The results were compared to typical data on normal cardiac physiology. The clinical effectiveness of our method was evaluated in a patient who had abnormal pulmonary blood flow. In normal cases, there was a strong correlation between the cardiac cycle and changes in pixel value. Sequential blood distribution images showed a normal pattern at determined by the physiology of pulmonary blood flow, with a symmetric distribution and no blood flow defects throughout the entire lung region. These findings indicated that pulmonary blood flow was reflected on dynamic chest radiographs. In an abnormal case, a defect in blood flow was shown as defective in color in a blood distribution map. The present method has the potential for evaluation of local blood flow as an optional application in general chest radiography.
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Development of a cardiac evaluation method using a dynamic flat-panel detector (FPD) system: a feasibility study using a cardiac motion phantom. Radiol Phys Technol 2007; 1:27-32. [PMID: 20821160 DOI: 10.1007/s12194-007-0003-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Revised: 09/01/2007] [Accepted: 09/05/2007] [Indexed: 10/22/2022]
Abstract
The purpose of this study is to investigate the feasibility of cardiac evaluation with a dynamic flat-panel detector (FPD), based on changes in pixel values during cardiac pumping. To investigate the feasibility of cardiac evaluation with a dynamic flat-panel detector (FPD), based on changes in pixel values during cardiac pumping. Sequential radiographs of a cardiac motion phantom and water-equivalent material step were obtained with an FPD system. Various combinations of cardiac output and heart rate were evaluated with and without contrast medium. The ventricular area and summation of pixel values in the ventricles were measured. The ejection fraction (EF) was calculated based on the rate of changes and then compared to EF obtained from computed tomography images. In addition, slight changes in pixel values were visualized by use of inter-frame subtraction and color-mapping. The result of a clinical case was examined according to cardiac physiology. There were strong correlations between EF and our results. There was no significant difference between the findings with and without contrast medium. When the heart rate was greater than 60 bpm, EF obtained with our method were underestimated. It is necessary for a patient to be examined at an imaging rate between 7.5 and 10 fps at least. In addition, a +/-1.2% change in pixel value was equivalent to a +/-10 mm change in the thickness of water. Color-mapping images were supported by cardiac physiology. Evaluating changes in pixel values on dynamic chest radiography with FPD has the potential to demonstrate cardiac function without contrast medium. Inter-frame subtraction and color-mapping are very useful for interpreting changes in pixel value as velocities of blood flow.
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Elgeti T, Proquitté H, Rogalla NE, Mews J, Hamm B, Schmalisch G, Rogalla P. Evaluation of a Reduced Dose Protocol for Respiratory Gated Lung Computed Tomography in an Animal Model. Invest Radiol 2007; 42:230-4. [PMID: 17351429 DOI: 10.1097/01.rli.0000255817.54192.eb] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We sought to evaluate and validate a low-dose protocol for respiratory-gated multislice computed tomography (CT) for volume calculations in small ventilated neonatal animals as a model for the ventilated human neonatal lung. MATERIALS AND METHODS Five mechanically ventilated newborn piglets were imaged in a multislice CT scanner (0.5-mm slice thickness, 4:16 pitch, 0.5 seconds rotation time, 120 kV) using a normal (100 mAs) and a reduced (10 mAs) dose protocol. All animals were scanned twice (at 100 and 10 mAs) at each of 3 different ventilator settings. Complete volume datasets were reconstructed throughout the respiratory cycle in increments of 10% using retrospective half-scan reconstruction. End-inspiratory volumes and volumes during maximal expiration (functional residual capacity) were calculated by a customized software and values for normal and reduced dose protocols were compared using Kolmogorov-Smirnov test and Bland-Altman plots. RESULTS Two volume datasets (one normal and one reduced dose protocol) showed artifacts on the axial images, which could not be analyzed by the software. Those values were determined after manual segmentation and excluded from final analysis. The mean (+/-SD) end-inspiratory volumes and functional residual capacity were 34.3 +/- 10.1 mL and 25.3 +/- 8.0 mL for the normal-dose protocol versus 33.1 +/- 10.0 mL and 24.7 +/- 8.1 mL for the reduced-dose protocol, respectively. There was no statistically significant difference between normal and reduced dose protocol (KS-Test: D = 0.14 < Dmax). CONCLUSION Lung volume calculation in ventilated newborn piglets (end-inspiratory volumes and functional residual capacity) can be performed using respiratory-gated multislice CT even at a substantially reduced dose (eg, to 10 mAs). This makes the technique a candidate for future pediatric use.
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Affiliation(s)
- Thomas Elgeti
- Department of Radiology, Charité Campus Mitte, Universitätsmedizin Berlin, Germany.
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