Quality evaluation of microscopy and scanned histological images for diagnostic purposes.

In this work we present a study for assessing and comparing the fidelity of biopsy and cytology images captured with two different devices, that is optical microscopes and scanners, at 40× magnification in bright field. The devices use different ways to magnify images. Microscopes use a set of lenses while scanners capture light through arrays of micro-photoreceptors. The objective is to carry out a quantitative evaluation to discern which of the two devices provides better image quality in terms of contrast, colour and stain. Since there is no unanimous consensus on quality metrics, we will make use of both an objective metric based on perceptual features, together with a subjective psychophysical test as the International Telecommunications Union (ITU) recommends in ITU-R BT.500 for such type of tests. Both techniques indicate a slight preference for the scanner over the microscope in terms of better image quality, considering defocus as the main problem followed by colour distortions. However, the image quality of both devices is suitable for clinical, educational and research purposes.

Laryngeal carcinoma: sclerotic appearance of the cricoid and arytenoid cartilage--CT-pathologic correlation.

PURPOSE: To assess the significance of sclerotic-appearing cricoid and arytenoid cartilage with computed tomography (CT) in patients with laryngeal carcinoma. MATERIALS AND METHODS: CT scans obtained in 75 patients with laryngeal carcinoma were prospectively studied; laryngeal CT studies obtained in 50 patients without laryngeal carcinoma were retrospectively reviewed. RESULTS: Twenty-four of the 75 patients (32%) with laryngeal carcinoma had sclerotic cartilage. Evaluation of pathologic specimens obtained in 12 of these 24 patients showed 11 cases of sclerotic arytenoid cartilage and two cases of sclerotic cricoid cartilage. Tumor infiltration was demonstrated in six of these cases but not in the seven others. In 11 of the 12 cases with pathologic proof, however, tumor was adjacent to the perichondrium. In the 12 cases without pathologic proof, the proportion was similar. The positive predictive value of this sign for cartilaginous invasion was 46%. CONCLUSION: Although it is not a reliable sign of cartilaginous invasion, sclerotic-appearing cricoid and arytenoid cartilage in patients with laryngeal carcinoma is predictive of the tumor to this cartilage.

Diameter, length and branching ratios in the bronchial tree.

This paper is concerned with morphology and pattern of branching in the bronchial tree and their interrelationships. Branching ratio (Rb), diameter ratio (Rd), and length ratio (R1) are the factors by which the number of branches, mean diameter and mean length increase in successive orders of branching. An analysis based on the concept of minimum work suggests that ideally Rd = R1/3 b, whilst geometric considerations suggest that R1 = R1/3 b. Thus Rd = R1. These theoretical results are compared with those obtained from measuring one human and six dog bronchial tree casts. Values obtained from the human lung are in close agreement with the predicted values, whilst in the dog lungs the agreement, though less good, is still close. Rb is determined antenatally, the reason for its particular value being unknown. Diameter and length of branches may be modelled postnatally by growth in a manner which ensures that Rd = R1 - R1/3 b.