CLINICAL MEDICINE

Detailed explanation-1: -Underexposed receptors result in images that are too light or low in density. Light images can also be caused by an increase in the source-object distance, or not placing the tubehead close enough to the patient’s face during exposure.

Detailed explanation-2: -This underexposure is likely due to improper radiographic technique (mAs too low) or Automatic Exposure Control phototimer malfunction.

Detailed explanation-3: -When the source to object distance increases, the intensity of the x-ray beam decreases following the inverse square law, this will result in a decrease in the intensity of the beam reaching the object, and this results in a decrease in image density (Figure 4).

Detailed explanation-4: -While the image processing adjusts the gray-scale, images with low signals will have increased noise and mottle, whereas images with high signal are associated with good image quality but high patient dose (Fig. 3). An underexposed image has high noise content, and therefore can be readily recognized.

Detailed explanation-5: -While underexposed images have smaller numbers of X-rays absorbed by the digital detector and can be recognized by a noisy appearance (Fig. 2), overexposed images can easily go unnoticed, resulting in needless overexposure and potential harm to the patient.