ABSTRACT
BACKGROUND AND AIM: To evaluate CT findings of pulmonary alveolar microlithiasis and correlate the CT with the pathologic findings. METHODS: The study included 10 patients with pathologically proven microlithiasis. Two independent observers evaluated the presence, extent and distribution of the CT findings. CT findings were compared with those at autopsy in two patients and with transbronchial biopsy in eight patients. RESULTS: All patients had a myriad of calcified nodules measuring approximately 1 mm in diameter. Close apposition of the nodules resulted in areas of ground-glass attenuation and consolidation, which were the predominant abnormality on CT in all 10 patients, involving 41% +/- 16.3 (mean +/- SD) and 30% +/- 4.8 of the lung parenchyma, respectively. Calcifications were also seen along interlobular septa, bronchovascular bundles and pleura. Other findings included interlobular septal thickening, thickening of bronchovascular bundles, nodules, and subpleural cysts. There was a solid agreement between the observers for the presence (kappa value; 0.77) and extent (Spearman rank correlation; r = 0.81 to 1.0 p < 0.01) of abnormalities. Autopsy specimens demonstrated microliths in alveolar airspaces and along interlobular septa, bronchovascular bundles and pleura. Subpleural small cysts were shown to represent dilated alveolar ducts. CONCLUSION: Pulmonary microlithiasis is characterised by the presence of numerous small, calcified nodules, calcifications along interlobular septa, bronchovascular bundles and pleura, ground-glass opacities, consolidation, and subpleural cysts. The cysts represent dilated alveolar ducts.
Subject(s)
Calcinosis/diagnostic imaging , Lung Diseases/diagnostic imaging , Pulmonary Alveoli/diagnostic imaging , Adult , Aged , Calcinosis/pathology , Diagnosis, Differential , Female , Humans , Lung Diseases/pathology , Male , Middle Aged , Pulmonary Alveoli/pathology , Statistics, Nonparametric , Tomography, X-Ray ComputedABSTRACT
We have developed an extremely small integrated microencoder whose sides are less than 1 mm long. It is 1/100 the size of conventional encoders. This microencoder consists of a laser diode, monolithic photodiodes, and fluorinated polyimide waveguides with total internal reflection mirrors. The instrument can measure the relative displacement between a grating scale and the encoder with a resolution of the order of 0.01 microm; it can also determine the direction in which the scale is moving. By using the two beams that were emitted from the two etched mirrors of the laser diode, by monolithic integration of the waveguide and photodiodes, and by fabrication of a step at the edge of the waveguide, we were able to eliminate conventional bulky optical components such as the beam splitter, the quarter-wavelength plate, bulky mirrors, and bulky photodetectors.
