EVALUATION OF IMAGE PROCESSING TECHNIQUES OF PHOTON-COUNTING X-RAY RADIOGRAPHY IN THORACIC DIAGNOSTIC IMAGING

【引言】光子计数X射线照相术（量子照相术：QR）是通过直接测量透过被摄体的X射线的光子数而生成的数字图像。利用CdTe多线传感器计算了光子数。它具有灵敏度高、线性度好、密度范围宽等特点，可获得高质量的图像。使用的X射线机是新设计的QR系统（Shimadzu，京都，日本）。[目的]通过与常规胸片（CONV）的对比研究，评价QR在肺部病变诊断中的应用价值。[材料与方法] 42例患者纳入本研究，其中肺癌18例，肺转移瘤9例，间质性肺炎5例，结核4例，淋巴瘤1例，错构瘤1例，过敏性肺炎1例，病毒性肺炎1例，尘肺病1例，机化性肺炎1例。8名放射科医师采用7分制评分法对QR与CONV进行评分比较， ...更多信息 D.所有观察者对高密度区（HFDA：外周肺野）和低密度区（LEDA：心后或脑下区）的正常结构和异常阴影的描述进行评分。结果采用Wilcoxon符号秩和检验。[结果] QR对所有正常结构及全区域各种异常阴影的显示均上级CONV（p<0.0001）。QR对肺内多发结节的描述上级CONY，尤其是LFDA。QR是一种数字成像技术。这与传统的射线照相或当前的数字射线照相有很大的不同，因为QR直接计数进入半导体传感器单元的光子的数量，而没有任何其他介质，例如，屏幕-胶片系统或存储荧光板。在临床上，QR对各种正常结构和整个密度区的异常阴影的描述优于CONY，具有上级的优势。这一结果可能反映了QR的上级密度分辨率，特别是在临床评价中，其密度分辨率的优越性可能超过空间分辨率的轻微劣性。QR被认为是一种非常有用的胸部数字诊断成像，具有宽动态范围。少

[INTRODUCTION] Photon counting X-ray radiography (quantum radiography : QR) offers digital images produced by directly measuring the number of photons of an X-ray which have permeated through the object. The photons are calculated by means of CdTe multi-line sensor. It gives a high quality image with the features of high sensitivity and good linearity over the wide range of density. X-ray machine used is newly devised QR system (Shimadzu, Kyoto, Japan).[PURPOSE] To evaluate the utility of QR on detection of pulmonary lesions, clinical studies were performed with comparison of conventional chest radiography (CONV).[MATERIALS AND METHODS] Forty two patients were included in this study ; eighteen lung cancer, nine metastatic lung tumor, five interstitial pneumonia, four tuberculosis, one lymphoma, one hamartoma, one hypersensitivity pneumonitis, one viral pneumonia, one pneumoconiosis, one organizing pneumonia. Eight radiologists scored QR comparing with CONV by 7-point rating scale metho … More d. All observers scored the description of normal structures and abnormal shadows in the high film density area (HFDA : peripheral lung field) and in the low film density area (LEDA : retrocardiac or subdiaphragmatic area). The results were analyzed by Wilcoxon signed rank sum test.[RESULTS] QR was superior to CONV in the depiction of all normal structures and all kinds of abnormal shadows in the whole area (p<0.000 1). QR was superior to CONY in the-description of multiple pulmonary nodules especially in LFDA.[DISCUSSION] QR is a kind of digital imaging technique. This is quite different from conventional radiography or current digital radiography on the point that QR directly counts the number of photons which come into the semi-conductive sensor unit without any other media, for example, screen-film system or storage phosphor plate. Clinically, QR was superior to CONY for description of many kinds of normal structures and abnormal shadows in the whole film density area. This result might reflect the superior density resolution of QR and its superiority of density resolution might surpass slight inferiority of spatial resolution especially in the clinical evaluation. QR was thought to be a very useful digital diagnostic imaging of the thorax with wide dynamic range. Less