Which pathologic condition requires a decrease in exposure factors?

The pathologic condition that requires a decrease in exposure factors is typically associated with a reduction in tissue density. Each of the conditions listed often involves a reduction in the body's normal tissue density, which affects how X-ray imaging should be performed.

Pneumothorax involves air in the pleural space, leading to a decrease in the lung's overall density. Since air is less dense than lung tissue, this condition requires lower exposure factors to avoid overexposing the image.

Emphysema also leads to changes in lung density. The destruction of the alveoli results in increased air spaces and decreased overall lung density, necessitating a reduction in exposure factors for optimal imaging.

Multiple myeloma is a bone marrow cancer that often leads to the formation of lytic lesions in bones, which results in decreased bone density. As a result, using lower exposure factors helps ensure that the areas of decreased density are adequately visualized without producing overly bright images.

Thus, decreasing exposure factors is appropriate for all these conditions due to their effects on tissue density, making it necessary to adjust imaging techniques accordingly. Therefore, the conclusion that all listed conditions require a decrease in exposure factors is well-founded.