Evaluating sunscreen ultraviolet protection using a polychromatic diffuse reflectance device.

Background: Sun protection factor (SPF) and UVA protection factor (UVA-PF) are determined using in vivo tests, with high exposures of subjects to ultraviolet (UV) radiation. Hybrid diffuse reflectance spectroscopy (HDRS) enables estimation of both indices using only trace amounts UVB. However, the equipment requires two expensive monochromators that must synchronously scan the spectrum.

Detection of retained surgical sponges.

The accuracy of radiographic detection of neurosurgical sponges was measured experimentally. Commercially available sponges were inserted into a cadaver in several paravertebral locations and radiographed. A total of 72 radiographs (90 sponges) were assessed, as well as an equal number of radiographs without sponges.

The effect of verification on the assessment of imaging techniques.

In order to measure the accuracy of a diagnostic imaging technique, the correctness of each observer decision must be determined. This is often difficult in clinical cases, and various strategies are frequently used to approximate the truth. Experiments using chest radiographs as an example are reported to show the pitfalls in those strategies.