Transillumination

Transillumination is the technique of sample illumination by transmission of light through the sample. Transillumination is used in a variety of methods of imaging. Transillumination is the technique of sample illumination by transmission of light through the sample. Transillumination is used in a variety of methods of imaging. In microscopy transillumination refers to the illumination of a sample by transmitted light. In its most basic form it generates a bright field image, and is commonly used with transillumination techniques such as phase contrast and differential interference contrast microscopy. In medicine transillumination generally refers to the transmission of light through tissues of the body. A common example is the transmission of light through fingers, producing a red glow due to red blood cells absorbing other wavelengths of light. Organs analysed include the sinuses, the breasts and the testes. It is widely used by pediatricians to shine light in bodies of infants and observe the amount of scattered light. Since their skeleton is not fully calcified, light can easily penetrate tissues. Common examples of diagnostic applications are: Failed obliteration of the processus vaginalis allows serous fluid to collect around the testes via a communicating connection between the tunica vaginalis and the peritoneum. The resulting hydrocele presents as a painless enlargement of the scrotum, similar to what may be encountered with testicular neoplasms. A convenient method to differentiate the conditions is to transilluminate the scrotum, as the hydrocele will appear a soft red while a solid tumor will not transmit light. Any uncertainty should be followed up with an ultrasound.