More explanation provided in the following example, by using fluorescent stain with two different colors, one stain in preferentially attached to the blood vessel walls and the other two regions of hypoxia. when the specimen scanned with two different laser, the two stain fluoresce with different colors and the resulting image clearly shows the relationship between the blood vessels and the hypoxia. This could be very useful to detect and monitoring the relationship between the density of blood vessels in tumor and regions of hypoxia.

We do believe now that the ability to image simultaneously with two laser wavelengths is important for fluorescence imaging, where it is important particularly in examining whole organ tissue slices.

Another microscope designed for characterization of charging and contaminating nano scale samples using low-vacuum, Field Emission Scanning - Electron Microscope (FEG-SEM).

Samples such as organic materials, substrates, porous materials, plastics and polymers are characterizing and contaminating by (FEG-SEM). Proprietary Helix detector technology combines a magnetic immersion lens and low vacuum SEM technology.

The SEM is type of electron microscope capable of producing high resolution images of sample surface. Due to the manner of which the image is created. SEM images have a characteristics 3D appearance and are useful for judging the surface structure of the sample image. The spatial resolution of the SEM depends on the size of the electron spot which in turn depends on the magnetic electron-optical system which produce the scanning beam.

Depending on the instrument, the resolution can fall somewhere between less than 1nm and 20 nm. In general SEM images are much easier and could be faster to interpret than other emission microscope devices, and many SEM images, beyond their scientific value, are actually beautiful.

Dr.Mohamed Selim El Kayyali
IEEE, CIPPRS, DICOM member