Pulmonary blood flow evaluation using a dynamic flat-panel detector: Feasibility study with pulmonary diseases

金沢大学医薬保健研究域保健学系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. © CARS 2009

胸部X線動態撮影の再現性の臨床 : ピクセル値の呼吸性変化

金沢大学医薬保健研究域保健学系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

動画対応フラットパネルディテクタによる肺機能画像診断法 : 肺シンチグラフィ所見との比較

金沢大学医薬保健研究域保健学系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

フラットパネルX線ディテクターを用いた胸部呼吸動態診断支援システムの開発

金沢大学医薬保健研究域医学系「胸部呼吸動態情報に基づく診断支援システムの開発」に向けて,(1)局所肺換気と高い関連を示す肺野内のピクセル値の呼吸性変化を定量化する手法の開発とその臨床評価,(2)局所肺血流と高い関連を示す縦隔部および肺野内のピクセル値の心拍動変化を定量化する手法の開発,(3)本法により取得した機能情報を効果的に診断するための表示システムの開発,を行なった.18年度は,特に(2),(3)について主として開発研究を実施した.正常症例7例における肺野内局所のピクセル値変化と,既知の循環生理とを比較し,本法による肺血流イメージングの可能性を明らかにした.心室・心房・大動脈弓・肺動静脈に相当する位置で計測したピクセル値と,心周期には高い相関が見られた.全ての正常症例において,心室収縮期には,心室のピクセル値は減少した.大動脈弓・肺動脈のピクセル値は急激に増加し,その後,次の心室収縮期まで緩やかに減少した.心室拡張期には,心房のピクセル値は急激に減少し,心室のピクセル値は増加した.心房のピクセル値は次の拡張期まで緩やかに増加した.肺野内のピクセル値は心拍にともない緩やかに変動した.すなわち,可視化されたピクセル値の変化は,肺門部から肺野末梢に拍出される既知の正常循環動態と一致した.呼吸動態および画像診断のために,(1)動画像の再生が可能,(2)画像から定量化された動態情報を効率的に表示,(3)それらを詳細な形態情報と関連付けて観察可能,などの要件を満たす画像表示システムを開発した.以上,動画対応FPDによる肺血流イメージングの可能性が示された.前年度の研究成果である,局所肺換気評価法と合わせ,本法は,簡便かつ迅速に機能情報を提供する新しい動態画像診断法として期待できる.また,微小なピクセル値の変化として,動画像上に表れる肺換気および肺血流の理解には,フレーム間差分による可視化が有用であった.本研究課題の成果はCTやMRIによる動態撮影に応用することも可能であり,胸部動態検査の発展に大きく貢献することが期待される.研究課題/領域番号:17032004, 研究期間(年度):2005 – 2006出典：「フラットパネルX線ディテクターを用いた胸部呼吸動態診断支援システムの開発」研究成果報告書　課題番号17032004（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-17032004/)を加工して作

Functional shoulder radiography with use of a dynamic flat panel detector

Our purpose in this study was to develop a functional form of radiography and to perform a quantitative analysis for the shoulder joint using a dynamic flat panel detector (FPD) system. We obtained dynamic images at a rate of 3.75 frames per second (fps) using an FPD system. Three patients and 5 healthy controls were studied with a clinically established frontal projection, with abduction of the arms. The arm angle, glenohumeral angle (G-angle), and scapulothoracic angle (S-angle) were measured on dynamic images. The ratio of the G-angle to the S-angle (GSR) was also evaluated quantitatively. In normal subjects, the G-angle and S-angle changed gradually along with the arm angle. The G-angle was approximately twice as large as the S-angle, resulting in a GSR of 2 throughout the abduction of the shoulder. Changes in G-angle and S-angle tended to be irregular in patients with shoulder disorders. The GSR of the thoracic outlet syndrome, recurrent dislocation of the shoulder joint, and anterior serratus muscle paralysis were 3-7.5, 4-9.5, and 3.5-7.5, respectively. The GSR of the anterior serratus muscle paralysis improved to approximately 2 after orthopedic treatment. Our preliminary results indicated that functional radiography by FPD and computer-aided quantitative analysis is useful for diagnosis of some shoulder disorders, such as the thoracic outlet syndrome, recurrent dislocation of the shoulder joint, and anterior serratus muscle paralysis. The technique and procedures described comprise a simple, functional shoulder radiographic method for evaluation of the therapeutic effects of surgery and/or rehabilitation. © 2014 The Author(s)

Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology