Because visual inspection cannot reliably distinguish certain skin discolorations from skin cancers, dermatologists at clinics have needed to perform tests of skin tissue taken from patients  At Westville Hospital, dermatological diagnostic costs were reduced by the purchase of a new imaging machine that diagnoses skin cancer in such cases as reliably as the tissue tests do
Consequently, even though the machine is expensive, a dermatological clinic in Westville is considering buying one to reduce diagnostic costs
Whether the principles on which the machine operates have been known to science for a long time