Which two technologist errors are most likely to result in incorrect histogram rescaling and lookup table adjustment?

Using incorrect collimation and processing a knee radiograph as a chest are both critical errors that can significantly affect histogram rescaling and lookup table adjustments in digital radiography.

When collimation is incorrect, it means that the area of interest is not adequately exposed, leading to a histogram that does not accurately represent the density of the anatomy that has been imaged. Proper collimation is essential because it helps define the region that should be evaluated, and deviations from this can result in misinterpretation of the data, skewing the histogram.

Processing a knee radiograph as a chest further complicates this issue because different anatomical structures have unique exposure characteristics. Each type of radiograph has a specific histogram model associated with it, and if data from one region (the knee) is evaluated using the model for another (the chest), the system will apply inappropriate adjustments based on erroneous assumptions about what the data should look like. This misalignment leads to drastic inaccuracies in image quality and diagnostic information.

These two errors highlight the importance of both accurate positioning and understanding the anatomical context of the imaging parameters to ensure successful histogram analysis and proper image quality.