The Path of Radiation
The Path of Radiation must include the area of interest (teeth and surrounding bone) and active sensor (Figure 1). As an example, if you expect to capture the distal half of a canine crown on a bitewing image, the canine must be covered with radiation and there must be active sensor in the path of radiation as shown by the PID’s position. The operator is responsible for putting all the pieces together to create diagnostic images. Here’s an analogy to make it easier to understand…the baseball glove has to be in the exact position to catch the baseball or the ball will land on the ground!
Figure 1 - The Path Of Radiation.
There are consequences when the path of radiation does not contain the teeth and the full sensor: if the sensor and the required teeth are not in the radiation’s path, they will not appear on the image (Figure 2A) and if the path of radiation does not cover the entire sensor, a cone-cut (an area of non-exposure) will result (Figure 2B)
(A) Active sensor was not behind the canine. (B) Sensor not fully covered by radiation resulted in a cone-cut.