Nobuaki Kohno

High-resolution CT findings of lung disease in patients with polymyositis and dermatomyositis.

The purpose of this study was to determine the type and distribution of interstitial lung disease seen in patients with polymyositis and dermatomyositis, using high-resolution computed tomography (HRCT). The presence and distribution of high-resolution CT findings were retrospectively evaluated in 25 patients with polymyositis/dermatomyositis. In 14 patients, a pathological diagnosis of pulmonary disease was obtained. Three lung specimens were also studied. Results showed that 23 patients had abnormal HRCT showing the following abnormalities: ground glass opacities (92%), linear opacities (92%), irregular interfaces (88%), airspace consolidation (52%), parenchymal micronodules (28%), and honeycombing (16%). A relatively high prevalence of airspace consolidation (52%) and a low prevalence of honeycombing (16%) were observed. Two patients with extensive consolidation proved to have diffuse alveolar damage; eight patients with either subpleural band-like opacities (n = 5) and/or airspace consolidation (n = 7) had bronchiolitis obliterans organizing pneumonia; four patients with honeycombing had usual interstitial pneumonitis. We conclude that HRCT findings in patients with polymyositis/dermatomyositis are nonspecific. However, a high prevalence of airspace consolidation and a low prevalence of honeycombing were observed. Predominant HRCT patterns are suggestive of the pathologic processes occurring in polymyositis/dermatomyositis.

Chronic eosinophilic pneumonia: evolution of chest radiograms and CT features.

Objective Our object is to describe and compare the findings on plain chest radiographs and CT scans in patients with chronic eosinophilic pneumonia of varying duration, as judged by their clinical history. Materials and Methods We retrospectively reviewed the initial chest radiographs and initial CT scans that were obtained before treatment with corticosteroid in 17 patients with pathologically proven or clinically diagnosed chronic eosinophilic pneumonia. Results Eleven of the 17 patients showed predominantly peripheral patchy or confluent consolidation with or without ground-glass opacities on chest radiography. Sixteen patients, on the other hand, showed various types of abnormalities with peripheral predominance on CT. The seven patients in whom the initial CT was performed within 1 month after the onset of symptoms had dense confluent consolidation (7/7) with or without ground-glass opacities. When the initial CT was performed 1–2 months after onset of symptoms, inhomogeneous patchy consolidation or nodules (5/7) or ground-glass opacities (2/7) were observed. When the initial CT was performed >2 months after the onset of symptoms, streaky or band-like opacities (1/3) or lobar atelectasis (1/3) was seen. Conclusion Patients with chronic eosinophilic pneumonia show an evolution of CT features at varying time intervals after the onset of disease.

Metastatic pulmonary calcification: early detection by high-resolution CT.

A 41-year-old man with a renal transplant was admitted with cough, fever, and dyspnea. Although chest radiography was normal, high-resolution CT demonstrated small hazy round opacities in the centrilobular regions throughout both lungs. The biopsy specimen revealed metastatic calcification in the alveolar septa and the walls of the bronchioles and arterioles. High-resolution CT may be useful for the early detection of metastatic pulmonary calcification when plain radiography is negative and therapy has the potential to reverse the process.

High-resolution CT and pulmonary function tests in collagen vascular disease: comparison with idiopathic pulmonary fibrosis.

To estimate whether the lung abnormalities seen in collagen vascular diseases (CVD) were similar or distinct to those seen in idiopathic pulmonary fibrosis (IPF), and to ascertain whether the extent of the abnormalities on high-resolution CT (HRCT) correlated with pulmonary function, we reviewed HRCT findings and pulmonary function test results of 64 patients with either CVD (n = 55) or IPF (n = 9). Response to corticosteroid treatment was also evaluated in 20 of the 64. High incidence of honeycomb lesion was observed in IPF (9/9, 100%) and in progressive systemic sclerosis (PSS) (11/14, 79%). CVD, except for PSS, had a low incidence of honeycomb lesion (27%). On the other hand, incidence of ground-glass shadow in CVD (47/55, 85%) was the same as that in IPF (8/9, 89%). Diffusing capacity significantly correlated with the extent of all parenchymal abnormalities in all CVD and IPF, with honeycomb lesion in PSS, and with ground-glass shadow or air-space consolidation in CVD except for PSS (r < -0.7, P < 0.001). In all 15 cases in which corticosteroid therapy was effective, no honeycomb lesions were seen. Collagen vascular disease, except for PSS, had a different pattern of disease than IPF. The morphologic changes seen on HRCT correlated well with pulmonary function in CVD.

CT findings in «pseudoalveolar» sarcoidosis

To determine the specific high resolution CT (HRCT) features for “pseudoalveolar” sarcoidosis, we reviewed HRCT of 10 patients with pathologically proven sarcoidosis. On HRCT the lesions of pseudoalveolar sarcoidosis were shown as homogeneous or inhomogeneous opacities 1–4 cm in diameter located either along the bronchovascular bundles or in the lung periphery adjacent to the pleural surface. The margin was irregular, and numerous nodules 1–2 mm in diameter were observed in the surrounding lung. Air bronchograms were observed in 6 patients. In addition to these lesions, other CT abnormalities such as nodules, groundglass opacities, thickened bronchovascular bundles, and interlobular septa were found in all 10 cases. Good response of pseudoalveolar sarcoid lesions to administration of corticosteroid was observed in all three cases in which follow-up CT was available.

Interpretation of Subtle Interstitial Chest Abnormalities: Conventional Radiography Versus High-Resolution Storage-Phosphor Radiography~A Preliminary Study

To evaluate the reliability of digital chest radiography in diagnosing subtle interstitial lung abnormalities, we performed several clinical studies including a comparison of conventional screen-film radiography and storage-phosphor radiography (2 K × 2 K pixels, 10 bit), and a comparison of conventional screen-film radiography and film-digitized radiography (2 K × 2 K pixels, 10 bit). From these previous studies, a spatial resolution of 0.2-mm pixel size was considered inadequate to diagnose subtle interstitial lung diseases. Under these circumstances, the newly developed Fuji Computed Radiography system (FCR 9000; Fuji Photo Film, Tokyo, Japan) has recently become available. This system provides 0.1-mm pixel size (4 K × 5 K pixels, 10-bit depth) and life-size hard copies (14×17 inches). To evaluate the reliability of new high-resolution storagephosphor radiography (FCR 9000) in diagnosing simulated subtle interstitial abnormalities (including simulated lines, micronodules, and groundglass opacities), the differences among radiologists in interpreting conventional screen-film radiographs and life-size high-resolution storage-phosphor radiographs were studied. Observation was made by eight experienced chest radiologists, and receiver-operating characteristic (ROC) analysis was performed. There was no significant difference in detecting in subtle simulated interstitial abnormalities between conventional film-screen radiography and high-resolution storage-phosphor radiography. For all three types of abnormalities, there was no significant difference between conventional and storage-phosphor radiography. In conclusion, the high-resolution storage-phosphor chest radiography (0.1-mm pixel size, 10-bit depth) may be substituted for conventional chest radiography in the detection of subtle interstitial abnormalities.

Dynamic range control processing of digital chest images : a clinical evaluation

Purpose: The clinical usefulness of an advanced image-processing system called “dynamic range control processing” was investigated, with which selected parts of the dynamic range of digital chest images could be controlled. Material and Methods: A comparative study of 3 different post-processed formats of storage phosphor (SR) images was performed in 35 patients with abnormalities in the chest. The 3 formats were SR images with standard mode (SR-standard), SR images with strong edge-enhancement (SR-enhanced), and dynamic range controlled SR images (SR-controlled). Results: For lung abnormalities, there was no difference among the 3 SR image formats. For normal mediastinal structures and lung abnormalities covered by the heart or diaphragm, SR-controlled and SR-enhanced images were significantly superior to SR-standard images, while no difference was found between SR-controlled and SR-enhanced images except for the trachea and bony structures. Conclusion: Dynamic range control processing appears to be a useful method for displaying SR chest images with an extremely wide dynamic range.

Dynamic Range Control Processing of Digital Chest Images

Purpose: The clinical usefulness of an advanced image-processing system called “dynamic range control processing” was investigated, with which selected parts of the dynamic range of digital chest images could be controlled.Material and Methods: A comparative study of 3 different post-processed formats of storage phosphor (SR) images was performed in 35 patients with abnormalities in the chest. The 3 formats were SR images with standard mode (SR-standard), SR images with strong edge-enhancement (SR-enhanced), and dynamic range controlled SR images (SR-controlled).Results: For lung abnormalities, there was no difference among the 3 SR image formats. For normal mediastinal structures and lung abnormalities covered by the heart or diaphragm, SR-controlled and SR-enhanced images were significantly superior to SR-standard images, while no difference was found between SR-controlled and SR-enhanced images except for the trachea and bony structures.Conclusion: Dynamic range control processing appears to be a usefu...

Image compression based on multiresolution decomposition: application to chest radiographs

We have designed an image compression scheme based on multiresolution decomposition using the quadrature mirror filters (QMFs), and applied it to chest radiographs. In order to assess the preservation of diagnostic image quality, we performed image review study using a diagnostic workstation. From the result of review by diagnostic radiologists, our method may be available in clinical practice.