Gouji Miura

High resolution CT findings in community-acquired pneumonia

PURPOSE Our goal was to clarify the high resolution CT (HRCT) findings of community-acquired pneumonia based on pathologic findings and to make a differential diagnosis between bacterial and atypical pneumonias. METHOD This study evaluated 32 cases with community-acquired pneumonia, including 18 cases with bacterial pneumonia and 14 cases with atypical pneumonia [mycoplasma pneumonia (n = 12), chlamydia pneumonia (n = 1), and influenza viral pneumonia (n = 1)]. HRCT images in these cases were space consolidation, ground-glass attenuation, thickening of the bronchovascular bundle, and distribution of abnormal attenuation. RESULTS Bacterial pneumonia frequently showed air space consolidation with segmental distribution (72.2%) that tended to locate at the middle and outer zones of the lung. Atypical pneumonia frequently showed centrilobular shadow (64.3%), acinar shadow (71.4%), air space consolidation and ground-glass attenuation with lobular distribution (57.1 and 85.7%, respectively), and tendency of the lesions to distribute at the inner layer of the lung in addition to the middle and outer layers (85.7%). CONCLUSION Characteristic HRCT findings of both bacterial and atypical pneumonia were demonstrated. These HRCT features seemed to reflect pathologic findings and the manner of lesional progression. This information may support the appropriate antibiotic therapy in medical practice.

CT findings of leukemic pulmonary infiltration with pathologic correlation

The aim of this study was to demonstrate the characteristic CT findings of leukemic pulmonary infiltration based on the pathologic findings. The CT findings of 11 leukemic patients with leukemic pulmonary infiltration were compared with those of 22 leukemic patients with other diseases as a control group. Evaluated pulmonary parenchymal CT findings included thickening of bronchovascular bundles and interlobular septa, prominence of peripheral pulmonary arteries, ground-glass opacities, air-space consolidation, and nodules. The CT-pathologic correlations for leukemic infiltration were evaluated in 7 patients. Frequent parenchymal CT findings were thickening of bronchovascular bundles (81.8%), prominence of peripheral pulmonary arteries (81.8%), and non-lobular and non-segmental ground-glass opacities (90.9%). The first two findings were significantly more frequently observed in leukemic infiltration than in the control group, had good interobserver agreement, and corresponded pathologically to leukemic cell infiltration around the pulmonary arteries, bronchi, or bronchioles. Non-lobular and non-segmental ground-glass opacity corresponded to leukemic cell infiltration within alveolar spaces and septa adjacent to the pulmonary arteries or bronchi and also corresponded to hemorrhage, edema, or diffuse alveolar damage. Thickening of bronchovascular bundles and prominence of peripheral pulmonary arteries are CT findings suggestive for leukemic infiltration and correspond to peribronchovascular tumor extension.

HRCT findings of chest complications in patients with leukemia

Abstract. High-resolution CT (HRCT) findings of several chest complications occurring in leukemic patients were reviewed. Although most entities show non-specific HRCT findings including ground-glass opacity and air-space consolidation, characteristic findings are observed in several pulmonary complications including Pneumocystis carinii pneumonia, fungal infections, miliary tuberculosis, leukemic infiltration, pulmonary edema, bronchiolitis obliterans, and bronchiolitis obliterans organizing pneumonia. A combination of these characteristic HRCT findings and the information obtained from the clinical setting may help in achieving a correct diagnosis of chest complications occurring in leukemic patients.

Paired inspiratory–expiratory thin-section CT findings in patients with small airway disease

Abstract The objective of this study was to evaluate minimal small airway disease (SAD) as reflected on paired inspiratory–expiratory CT findings. Seventy-two subjects, 34 with SAD, 11 with normal lung function, and 27 with chronic obstructive pulmonary diseases (COPD), underwent thin-section CT during deep inspiration and expiration at upper, middle, and lower lung levels. Evaluation of CT measurement was performed between inspiratory and expiratory CT attenuation of lung parenchyma, in non-dependent and dependent lung at each of the three levels. Visual assessment of mosaic patterns and attenuation differences was also performed using the inspiratory and expiratory images. Patients with SAD were differentiated from those with COPD, by visual assessment and from the CT measurements. Visual assessment failed to differentiate between the SAD and normal groups. However, one measurement, an inspiratory–expiratory attenuation difference in the dependent lower lung, was different between SAD and normal group. Early small airway disease may be indicated by an inspiratory–expiratory attenuation difference in the dependent lower lung using the simple method of a paired inspiratory–expiratory CT.

201Tl SPECT as an indicator for early prediction of therapeutic effects in patients with non-small cell lung cancer

This study retrospectively investigated the good parameters on thallium-201 chloride (201T1) SPECT for early assessment of the therapeutic effects in patients with non-small cell lung cancer.Based on tumor response as determined by chest CT scan about 9 weeks after the end of irradiation with adjuvant chemotherapy, the subjects were divided to the responder group (tumor regression > 50%, n = 13) and non-responder group (tumor regression < 50%, n = 13).201T1 SPECT was performed before and at the halfway through the course of therapy (average tumor dose, 27.4 Gy ± 4.5) in all the patients. SPECT was conducted twice 15 min (early scan) and 120 min (delayed scan) after intravenous injection of 148 MBq (4 mCi) of201T1. Tumor-to-contralateral normal lung tissue count ratios on both scans were calculated as early and delayed uptake ratios (EUR and DUR), and a retention index (RI) was also derived from these ratios.In the responder group, a significant decrease in DUR and RI halfway through the therapy was observed compared to pretreatment (2.6 ± 0.6 vs. 3.5 ± 1.0; p < 0.01, and -2.3% ± 25.5 vs. 37.4% ± 17.8; p < 0.001, respectively), even though EUR did not change significantly (N.S.). By contrast, in the non-responder group, there were no significant changes in any of these parameters (N.S.). When comparing DUR and RI for the two groups halfway through the therapy, DUR and RI were significantly lower in the responder group (both; p < 0.01), but no significant difference was noted in EUR (N.S.), and the percent reduction in tumor size did not correlate with the percent decrease in DUR or RI (N.S.).These results indicate that the extent of decrease in DUR and RI after therapy can be a useful parameter for early assessment of the therapeutic effects in patients with non-small cell lung cancer.

Radionuclide Angiography and Ventilation/Perfusion Studies in Two Patients With Systemic Arterial Supply to the Basal Segment of the Left Lung

The findings of radionuclide studies in two adult men with systemic arterial supply to the basal segment of the left lung without sequestration are reported. Radionuclide angiography with Tc-99m human serum albumin-diethylenetriamine showed that the lung was perfused by the systemic circulation rather than by the pulmonary artery. Ventilation and perfusion scans with Xe-133 and Tc-99m MAA showed a V/Q mismatch in this area, suggesting the presence of normal bronchial communication without a pulmonary arterial supply. These results also suggest the presence of a left-to-left shunt in the well-ventilated lung in this area. MRI and conventional angiography showed an aberrant artery arising from the descending thoracic aorta, supplying the basal segment of the left lung without a pulmonary artery. In both patients, left lower lobectomy showed normal alveobronchial structures without sequestration. Radionuclide angiography and ventilation/perfusion imaging appear to be reliable noninvasive methods for diagnosing this rare anomaly with a left-to-left shunt.

Superimposition of In-111 platelet SPECT and CT/MR imaging in intracardiac thrombus

An initial attempt to superimpose in-111-labeled platelet SPECT over CT/MRI in two patients with intracardiac thrombus is presented. One patient was a 65-year-old woman with a history of mitral and tricuspid valve replacement. This patient had a large thrombus measuring 74 x 43 x 34 mm in the right atrium. Fusion imaging with CT showed increased in-111 activity on the surface of the thrombus, which was visualized as circular activity on a planar image. The other patient was a 72-year-old woman who had a thrombus measuring 17 x 14 x 12 mm at the cardiac apex. Planar imaging showed two discrete areas of abnormal in-111 activity. Superimposition of the SPECT image over MR revealed that one of these areas corresponded to the small thrombus, whereas the other related to a previous subendomyocardial biopsy. In both patients, the activity ratio of the abnormal in-111 accumulation versus the cardiac chamber on SPECT was greater than that on planar images. The correlation of in-111 platelet SPECT and CT/MRI was useful in accurately localizing the intracardiac thrombus.

Thin-section oblique CT with 25° cranially tilted images Evaluation of pulmonary tumors adjacent to the interlobar fissures

Purpose: Thin-section oblique CT with cranially tilted axial scans can provide better visualization of the interlobar fissures than thin-section CT with conventional axial scans. the purpose of this study was to evaluate the usefulness of oblique CT scans for pulmonary tumors adjacent to the interlobar fissures. Material and Methods: Cranially tilted and conventional axial images were obtained by thin-section CT in 10 patients with solitary pulmonary tumors adjacent to the interlobar fissures. Conventional CT with a 2-mm collimation and thin-section oblique CT with a 25° cranial tilt were obtained. Results: the images obtained by thin-section oblique scanning visualized the relationship between the pulmonary tumor and the interlobar fissures in all 10 patients, whereas in 6 patients the thin-section conventional images did not. the pulmonary tumors in these 6 patients included all 5 that were adjacent to the minor fissures. Conclusion: Thin-section oblique CT may be more useful than thin-section conventional CT in evaluating the relationship between pulmonary tumors and the minor fissures.