Ji Woong Kim

Treatment of Becker's nevi with a long-pulse alexandrite laser.

BACKGROUND Beckers nevus (BN) can be a distressing cosmetic handicap for patients and a treatment challenge for physicians. Various treatment modalities have been used, but repigmentation commonly occurs after treatment. OBJECTIVE To evaluate the efficacy of long‐pulse alexandrite laser in the treatment of BN. MATERIALS AND METHODS Eleven Korean patients with Fitzpatrick skin type III to V were included in this study. A long‐pulsed alexandrite laser with a wavelength of 755 nm and a pulse duration of 3 ms was used. Patients were treated with a fluence of 20 to 25 J/cm2 and a spot size of 15 to 18 mm. Cryogen spray cooling was not used. RESULTS Two patients had excellent responses, five had good responses, and four had fair responses. Hair density simultaneously decreased with treatment in all patients. Although mild hypopigmentation was observed in some patients, and partial hypertrophic scarring was observed in one patient, the outcomes were cosmetically acceptable. No repigmentation was noted during the follow‐up period. CONCLUSION A long‐pulsed alexandrite laser without cryogen spray cooling is an effective and safe alternative in the treatment of BN. The authors have indicated no significant interest with commercial supporters.

Better understanding of digital photography for skin color measurement: With a special emphasis on light characteristics

Background/Aim: Digital photography can be used to measure skin color colorimetrically when combined with proper techniques. To better understand the settings of digital photography for the evaluation and measurement of skin colors, we used a tungsten lamp with filters and the custom white balance (WB) function of a digital camera.

A novel consistent photomicrography technique using a reference slide made of neutral density filter

Obtaining consistent photomicrographic images of pathology slides is not always easy because of many different types and settings of the equipment such as the microscopes and digital cameras. In this study, we developed a photomicrography technique that could acquire consistent images of pathology slides. The neutral density (ND) filter was attached to a transparent glass slide as a reference slide, photographed using consistent settings, and acquired images that harbored all of the areas of gray, white, and black. In the same way, the slide was replaced by the actual pathology slide, and photomicrographed. To simulate different light environment, the above photographic session was repeated using two different light intensities and microscopes. A graphic program was used to adjust levels of the reference slide images and this leveling, or calibration, was saved as a file for each. This file for leveling process was applied to actual subsequent photomicrographic images. The same sites of noncalibrated and calibrated images of the pathology slide were calculated into CIELAB or CIE L*a*b* coordinates. Then, the color differences (ΔE*ab) were calculated. As results, in the study using a 50% transmittance ND filter, two original different images were made nearly identical to the unaided eye, especially in two‐point (white and gray) and three‐point (black, white, and gray) leveling. In comparison of different light intensities, the ΔE*ab of the selected area was 0.9 in two‐point leveling. Between different microscopes, 10.7 of ΔE*ab was the smallest value in three‐point leveling. This method would be helpful for acquiring consistent photomicrographic images of pathology slides. Microsc. Res. Tech., 2011.