Three-dimensional image detection

In another application of multiple position detection, a cooled CCD detector has been used to detect four spots of fluorescein-labeled HSA, which bind to anti-HSA antibody that is immobilized on a fused silica plate.(134) Irradiation of the waveguide at a 70° angle of incidence on the top surface generates an evanescent wave in the waveguide. The CCD is positioned parallel to the top surface of the waveguide to capture the emission of the labeled HSA. Three-dimensional images of the scans are shown in this study. 

ToF systems are well suited to the pulsed nature of SIMS and MALDI measurements, and combine many characteristics that are advantageous to imaging experiments. High detection efficiency, parallel detection, and a wide m/z detection range have made them ubiquitous for MALDI and SIMS-MSI. Recent improvements in measurement speed have particularly benefited MSI experiments. Modem commercially available MALDI-ToF instruments are equipped with solid-state lasers that allow acquisitions at up to 2 kHz. Such speed is a prerequisite for the development of higher spatial resolution analysis and three-dimensional imaging or for the analysis of large animal/ patient series of tissues. 

Figure 7.17. By lighting up each hght emitting diode (LED) successively and noting which photodiodes grouped opposite detect the light the position of the limiting surfaces of the log can be determined very accurately, +1 mm. Typically there are three pairs of scaimers around the log. Scans are repeated at 100 mm intervals along the log to build up a three-dimensional image. This is a robust system with no moving parts from Kockums Rema).

One of the most recent applications of nuclear chemistry is the use of positron emission tomography (PET) in the measurement of dynamic processes in the body, such as oxygen use or blood flow. In this application, a compound is made that contains a positron-emitting nuclide such as C-11, 0-15, or N-13. The compound is injected into the body, and the patient is placed in an instrument that detects the positron emission. A computer produces a three-dimensional image of the area. 

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