To study the complications of total laryngectomy, we evaluated 471 previously untreated patients who underwent total laryngectomy between 1980 and 1997. This series consisted of 358 patients with primary carcinoma of the larynx and 113 with carcinoma of the hypopharynx. Concurrent neck dissection was performed in 85% of patients. Complications were studied in relation to age, T and N stage, previous tracheostomy, neck dissection, margins, reconstruction, tracheoesophageal puncture, and surgeon. Complication treatment and hospitalization were also evaluated. The overall complication rate was 30.7%, with 29.2% major and 6.5% minor complications. The mortality rate was 0.6% (3/471). Pharyngocutaneous fistula was the most frequent wound complication (21%), followed by wound infection (4.2%) and hemorrhage (2.3%). Pneumonia (1.4%) and embolism (0.4%) were the most frequent medical complications. Hypopharyngeal tumors, neck dissection, and extended procedures had a significantly higher rate of complications. Complication causes, prevention, and treatment are discussed.

A computerized method to automatically detect malignant masses on digital mammograms based on bilateral subtraction to identify asymmetries between left and right breast images was developed. After the digitization, in order to align left and right mammograms the breast border and nipple were automatically detected. Images were corrected to avoid differences in brightness due to the recording procedure. Left and right mammograms were subtracted and a threshold was applied to obtain a binary image with the information of suspicious areas. The suspicious regions or asymmetries were delimited by a region growing algorithm. Size and eccentricity tests were used to eliminate false-positive responses and texture features were extracted from suspicious regions to reject normal tissue regions. The scheme, tested in 70 pairs of digital mammograms, achieved a true-positive rate of 71% with an average number of 0.67 false positives per image. Computerized detection was evaluated by using free-response operating characteristic analysis (FROC). An area under the AFROC (A1) of 0.667 was obtained. Our results show that the scheme may be helpful to the radiologists by serving as a second reader in mammographic screening. The low number of false positives indicates that our scheme would not confuse the radiologist by suggesting normal regions as suspicious.

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Abstract. An essential and indispensable component of automated microscopy framework is the automatic focusing system, which determines the in-focus position of a given field of view by searching the maximum value of a focusing function over a range of z-axis positions. The focus function and its computation time are crucial to the accuracy and efficiency of the system. Sixteen focusing algorithms were analyzed for histological and histopathological images. In terms of accuracy, results have shown an overall high performance by most of the methods. However, we included in the evaluation study other criteria such as computational cost and focusing curve shape which are crucial for real-time applications and were used to highlight the best practices.