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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.

We describe the anatomy of incomplete interlobar fissures with and without septal structures. Twenty-eight fused areas in specimens obtained during 21 autopsies were examined histologically. In 12 of the 28 fused areas, there was a mixture of septal structures with and without defects. In the remaining 16, there were some septal structures. Septal structures consisted of inner layers from both lobes. These results suggest that linear shadows at interlobar fissures on computed tomography do not necessarily reflect complete interlobar fissures. Assessment of incomplete interlobar fissure is important with regard to collateral ventilation and pulmonary disease processes.

Rationale and Objectives: Some septal structures have been observed in the areas of incomplete interlobar fissures (IIFs) in resected lungs. We describe the anatomy of IIFs with or without the presence of septal structures., Methods: Twenty fused areas from 16 autopsy cases were examined histologically. Other septal structures outside the areas of IIFs also were examined., Results: In 10 of the 20 fused areas, there was a mixture of septal structures with and without defects. In the remaining 10, there were no septal structures. The septal structures consisted of two inner layers from both lobes. Other septal structures examined were the same as ones observed in the IIFs., Conclusion: Linear shadows seen at interlobar fissures and on computed tomography scans do not necessarily depict the presence of complete interlobar fissures. The absence of linear shadows does not necessarily imply the absence of septal structures.

Rationale and Objectives: Typical models of the human bronchial tree depict regular branching. However, some anatomic studies also have revealed irregular dichotomies in the human lung. We therefore studied the patterns of bronchial branching in the human lung., Methods: We examined a normal right lung. Bronchial branchings were traced up to terminal bronchioles (TBs) in both regular and irregular dichotomies., Results: In 256 TBs in peripheral regions, the number of branchings varied from 11 to 23; the largest number was found in the S10c of the basal segment, and the average was 15. In 354 TBs in hilar regions supplied by irregular dichotomies, the number of branchings ranged from 9 to 15, with the average being 10. In secondary pulmonary lobules, bronchioles supplying the secondary pulmonary lobules reached TBs in two or three divisions., Conclusion: Irregular dichotomies are too frequent to be neglected in the interpretation of radiologic and physiologic findings.

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.

There have been previous reports on the differentiation of benign pulmonary nodules from malignant ones using CT number. However, most of the nodules were without calcification, and diagnosis could be made only in limited cases. In the present study we established new multiple variables such as relative high density over the 75th percentile, inner gradient number (inner irregular rate), edge gradient number (edge irregular rate) and increased area rate (IAR). They are automatically calculated from CT data by computer. These variables are transformed into relative values, enabling comparisons of nodules without a standard reference phantom. With IAR, pulmonary nodules were classified into three types: type 1 (IAR 1.0-1.4), a high-density solid mass with well-defined margin; type 2 (IAR 1.4-2.0) between type 1 and type 3; and type 3 (IAR > 2.0) a low-density infiltrated mass with ill-defined margin. We studied 52 cases with solitary pulmonary nodules, whose diagnoses were confirmed either histologically or on follow-up. There were 34 benign nodules and 18 primary lung cancers. Using step-wise multiple regression with three variables, 42 of 52 cases were correctly diagnosed. Twenty-four of 28 type 1 cases and all 14 of type 2 cases were correctly diagnosed. This computer analysis is considered to be useful in distinguishing between benign and malignant solitary pulmonary nodules.

Azygos lobe is a comparatively rare anomaly of the lung, and its radiologic features are well known. However, reports concerning its bronchial and vascular supply are few. The authors describe the bronchial and vascular supply of an azygos lobe in the autopsied right lung of a 43-year-old man. In the inflated fixed lung, the azygos lobe was supplied by the bronchi of the apical sub-subsegmental branch of B1b (B1bi) and B1a (B1ai) accompanied by the accompanied by the pulmonary artery of the same sub-subsegments (A1bi, A1ai). The lateral sub-subsegmental branches of B1aii and B1bii accompanied by the pulmonary artery did not supply the azygos lobe. The azygos lobe was supplied by V1a. V2 but not V1b.

Three-Dimensional MR angiography (3D-MRA) of the lung was performed in 5 healthy volunteers and 14 patients with primary pulmonary cancer in the hilum, and compared with 2D-MRA. As 3D-MRA could be obtained with single breath holding after intravenous bolus injection of Gd-DTPA, pulmonary vessels of the hilum and peripheral zone were demonstrated more definitely than those of 2D-MRA. In all patients except one case, the relation between the tumor and pulmonary vessels was visualized more clearly by 3D-MRA than 2D-MRA. This technique is considered a non-invasive and effective method for evaluation of pulmonary vessels in the patient with hilar tumor.