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Purpose: The present study assessed the usefulness of CT for diagnosis of pulmonary emphysema (PE) using teleradiology., Methods: We reviewed 95 cases (56 men and 39 women, ranging in age from 18 to 89 years) who had undergone CT examination between June 2002 and January 2003. CT images were transmitted via ISDN by DICOM to our hospital, and displayed in 4-image and 1-image format for reading on an image viewer., Results: In 72 of the total 95 cases, both 1-image and 4-image displays were normal, and no PE was detected. Of the remaining 23 patients, PE was found in 22 on 4-image display and in all 23 on 1-image display. The same grade and subtype were observed on 4-image and 1-image displays in 19 cases. On the other hand, difference in diagnosis between the two types of display was obtained in four cases, in which mild low attenuation areas (LAAs) such as grade 1 or grade 2 centrilobular emphysema were found on the 1-image display but not seen on the 4-image display., Conclusions: The diagnosis of PE can be made by CT examination using teleradiology even in cases of mild lesions, when, for example, LAAs were found on the 1-image display but not seen on the other one. Therefore, teleradiology enables rapid diagnosis even in medical institutions where no expert chest radiologist is present.

99mTc-Technegas scintigraphy is used for evaluation of abnormality of ventilation in pulmonary emphysema. Although the abnormality of ventilation distribution is very easy to find, there is not an objective index. The evaluation is subjective and different by each radiologist. It was also difficult to compare each cases and the clinical course in the same case. The present study for quantitative evaluation has proved that excellent correlations is obtained between the mean voxel values of the lung and stage classification. Furthermore, a correlation is observed between the mean and FEV1.0%. These deta indicate that quantitative analysis of SPECT seem to be useful to classify the clinical stage and compare the each cases. And respiratory function decreases as much as chronic pulmonary emphysema exists in the lower lung field.

Scintigraphy with 99mTc-technegas was recently introduced for clinical imaging of lung ventilation. This method has been found to be useful in emergencies, to be more suitable for single photon emission computed tomography (SPECT) than other agents used in ventilation scintigraphy, and could reveal abnormalities in ventilation more easily than high resolusion computed tomography (HRCT) in pulmonary emphysema. We compared 99mTc-technegas SPECT with HRCT in six regions: the right upper, middle, and lower lobes, the left upper lobe, the lingula, and the left lower lobe, in 15 patients with pulmonary emphysema. Patients with centrilobular emphysema tended to show stronger changes in upper lobes than in lower lobes on both 99mTc-technegas SPECT and HRCT. Some regions showed no change on HRCT but various changes on 99mTc-SPECT. Patients with panlobular emphysema showed severe changes on 99mTc-SPECT in lower lung fields in which well-demarcated areas of low attenuation were not seen on HRCT. We conclude that 99mTc-SPECT is useful for detecting early changes and panlobular changes in pulmonary emphysema.

Interstitial pulmonary emphysema (IPE) is the initial manifestation of ventilator-induced barotrauma. We report two patients in whom computed tomography was useful in showing IPE.

This study was undertaken to assess the usefulness of technetium-99m technegas scintigraphy axial images (technegas) compared with high resolution CT (HRCT) in 12 patients with pulmonary emphysema. All patients were male adult and heavy smokers and their mean age was 65. All patients inhaled 505 MBq technegas in several tidal volume breaths in the supine position without breath holding. SPECT imaging was performed by a Picker model Prism 2000. HRCT was performed after technegas. The technegas images showed different degree of changes from areas of heterogeneity to hot spots or defects. In emphysema, HRCT images showed low attenuation areas varying in size and number. In 4 of 12 patients, the degree of abnormal findings on technegas increased according to the degree of abnormal findings on HRCT. In the remaining 8 patients, however, more detailed findings were shown by technegas than by HRCT. There was no patients in which HRCT showed a greater changes than on technegas. HRCT can demonstrate low attenuation areas, even less than 5 mm in diameter. Moreover previous reports showed that aerosol inhalation would also demonstrate the airway disease. Assessment of the degree of involvement revealed by both methods indicated the superiority of technegas over HRCT. We conclude that technegas can represent the ventilation involvement easily more than HRCT in pulmonary emphysema.

A 17-year-old female with anorexia nervosa developed pneumomediastinum, subcutaneous emphysema, retroperitoneal emphysema, interstitial pulmonary emphysema and epidural emphysema (epidural emphysema; air between the dura mater and the vertebral arch). She had no history of bronchial asthma. The mechanism was presumed to be weakness of the alveolar wall due to malnutrition, leading to rupture of alveoli, followed by air entering the interstitium and dissecting along perivascular sheaths (interstitial pulmonary emphysema) into the mediastinum. A further increase in mediastinal pressure may bring about opening of the fascial planes along great vessels and allow air to penetrate into subcutaneous tissues and the spinal canal. These types of emphysema have been reported in bronchial asthma cases and in those on positive pressure breathing. To our knowledge, there are no previous reports of anorexia nervosa associated with these phenomena.