North Ryde Medical Imaging
The long used theoretical model that purports to predict the risk of cancer from radiation exposure looks to be obsolete. The many decade old LNT model predicted there was a small but significant cancer risk from low level radiation exposure. But this looks to be false. In fact, there has never really been empirical evidence to support the models predictions.
North Ryde Radiology
The linear No threshold Model (LNT model), was based on the belief that there was no safe dose level of radiation; that the risk of cancer increased in direct proportion to increased radiation exposure. But this ignored the notion that the human body can adequately repair damage from lower levels of radiation exposure. As we are always exposed to at least some background radiation on a regular basis this ability to repair low level damage is not a far-fetched claim. High levels of radiation do raise the risk of cancer, but below a certain point the low radiation levels appear completely insignificant.
Studies of insects have shown that high levels of radiation cause mutation and cancer, but that low levels basically have no effect at all. Studies of human beings exposed to radiation several decades ago have yielded identical results- low levels of radiation exposure have no effect on the risk of cancer.
The amount of radiation used in devices such as a CT scan or general X-ray is very low. It is comparable to the background radiation we are exposed to in a single day, and this appears to be well below the tolerable threshold. While members of the population do suffer cancer any earlier exposure to medical imaging does not appear to have any affect upon this problem.
North Ryde Ultrasound
Most medical imaging such as ultrasound does not involve radiation. The devices that do involve radiation operate at very low levels, which have become even lower as technology has advanced. There appear to be no significant risk from these devices.