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To assess the ability to detect and characterize middle ear effusion in children using A-mode ultrasonography.

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Purpose To further enhance and assess the ability to characterize middle ear effusion (MEE) using non-invasive ultrasound technology. Materials and Methods This is a prospective unblinded comparison study. Fifty-six children between the ages of 6 months and 17 years scheduled to undergo bilateral myringotomy with pressure equalization tube placement were enrolled. With the child anesthetized, the probe was placed into the external ear canal after sterile water was inserted. Ultrasound recordings of middle ear contents were analyzed by computer algorithm. Middle ear fluid was collected during myringotomy and analyzed for bacterial culture and viscosity. Results Ultrasound waveforms yielded a computer algorithm interpretation of middle ear contents in 66% of ears tested. When a result was obtained, the sensitivity and specificity for successfully characterizing middle ear fluid content as either void of fluid, thick fluid (mucoid), or thin fluid (serous or purulent) was at least 94%. Mucoid effusions had higher measured viscosity values (P=0.002). Viscosity measures were compared to culture result, and those with low viscosity (thin consistency) had a higher likelihood of having a positive culture (P=0.048). Conclusion The device sensitivity and specificity for fluid detection was 94% or greater among interpretable waveforms (66% of those tested). Although this technology provides important information of the middle ear effusion presence and characteristic, further technological improvements are needed.

The distal airways, defined anatomically as the region of the respiratory system including the terminal bronchioles through alveoli, were characterized in the guinea pig by means of light microscopy and by both scanning and transmission electron microscopy. The epithelium of the terminal bronchioles was comprised of two cell types. Ciliated cells were cuboidal and contained long thin microvili, ellipsoid mitochondria, and both rough and smooth endoplasmic reticulum. Nonciliated (Clara) cells were dome-shaped and usually protruded into the bronchiolar lumen. Numerous large mitochondria, granules of varying density, and crystalloid inclusions were notable in nonciliated cells. Respiratory bronchioles were characterized by a smooth-surfaced, low cuboidal epithelium. The cells in this region contained the crystalloid material found in terminal bronchioles, numerous large mitochondria, lysosomelike inclusions, and unusual tubular structures arranged in a matrix. The epithelium became progressively squamous toward the alveolar duct, where transition from bronchiolar cells to pneumocytes occurred. Transitional zones consisted of cells which, in addition to the above-mentioned structures, contained inclusions with internal laminations. These inclusions were structurally similar to the lamellar bodies observed in typical type II pneumocytes of the alveoli. The epithelium of both the alveolar ducts and alveoli was composed of type I and type II pneumocytes. Classical type I pneumocytes were squamous and very similar in cytoplasmic characteristics to the endothelial cells of the adjacent capillaries. Type II pneumocytes were characterized by the presence of lamellar bodies and numerous mitochondria.