TRANSILLUMINATION IMAGING FOR EARLY SKIN CANCER DETECTION

Frequent screening of suspicious skin pigmentations is of paramount importance since, at an early stage, skin cancer has a high cure rate and, in most cases, requires a simple treatment. In this paper, we present a new methodology for early detection of skin cancer based on the analysis of a pair of cross-polarization and side-transillumination images to examine surface pigmentation and vascularization characteristics of a lesion. Initially, the two images are automatically segmented by three separate procedures, and then the most accurate results are selected by a scoring stage. Finally, classification of the lesion as malignant or benign is accomplished by measuring the amount of hypervascularity around the pigmented area. When applied to a set of skin lesions, the two-stage methodology provided a 93.3 % success rate of correct image segmentation, and it was able to classify correctly lesions as malignant or benign with 86.9 % accuracy. The automatic segmentation procedure was validated against expert manual segmentation, whereas the final lesion classification was validated against findings from pathology. These results provide strong support for the importance of transillumination imaging in the early detection of skin cancer

Design of POSICAM: A high resolution multislice whole body positron camera

A high resolution (6mm), multislice (21) whole body positron camera has been designed with innovative detector and septa arrangement for 3-D imaging and tracer quantitation. An object of interest such as the brain and the heart is optimally imaged by the 21 simultaneous image planes which have 12 mm resolution and are separated by 5.5 mm to provide adequate sampling in the axial direction. The detector geometry and the electronics are flexible enough to allow BaF/sub 2/, BGO, GSO or time of flight BaF/sub 2/ scintillators. The mechanical gantry has been designed for clinical applications and incorporates several features for patient handling and comfort. A large patient opening of 58 cm diameter with a tilt of +-30/sup 0/ and rotation of +-20/sup 0/ permit imaging from different positions without moving the patient. Multiprocessor computing systems and user-friendly software make the POSICAM a powerful 3-D imaging device. 7 figs

Incorporating endoscope in middle ear surgery

We conducted a study to evaluate the use of a pediatric rigid otoendoscope for determining the extent of middle ear disease and for assessing ossicular integrity and mobility during tympanoplasty. Our study population was made up of 132 patients who were undergoing surgery for the treatment of chronic suppurative otitis media; of this group, 41 patients underwent otoendoscopy and 91 underwent scutum lowering for purposes of visualization. In the otoendoscopy group, the ossicles were successfully visualized and their mobility assessed in 34 patients; the remaining 7 patients subsequently underwent scutum lowering. A 30° endoscope allowed for complete visualization of the middle ear in almost all of the 34 cases. The mean duration of surgery for the 34 patients in the otoendoscopy group was 62.85 minutes (±15.57), which was significantly shorter than the duration of surgery (71.23 ± 15.65 min) for the 98 patients who underwent scutum lowering (p \u3c 0.005). A total of 50 patients required less than 60 minutes of surgical time-26 of 34 (76.5%) in the endoscopy group and 24 of 98 (24.5%) in the scutum-lowering group. Statistical analysis revealed that the possibility of completing a procedure in less than 60 minutes was 73.65% (±12.56%) when endoscopy was used and 58.62% (±12.60%) when scutum lowering was used-again, a statistically significant difference (p \u3c 0.005). We conclude that incorporation of an angled otoendoscope into middle ear surgery is a worthwhile alternative to scutum lowering