There is no risk to develop cancer or leukemia if the exposure to radiation is under 100mSv according to the International Commission of Radiation Protection (ICRP)'s counsel.
http://www.icrp.org/The health screening tests levels conducted at Tokyo Midtown Clinic
are thought to be a health concern since the figures are Chest X-ray (0.04mSv or less), Chest CT (10mSv or less), Abdomen CT (10mSv or less), Visceral Fat CT (0.5mSv or less), Upper gastro-Intestinal tract radiographic examination (0.6mSv or less) which comes to less than 100mSv even when all tests are summed up.
※These figures will be smaller for people with a slender figure.
Some sources state that the risk of cancer increases by frequent use of the CT, but the CT has a capability to do a detailed test without a preliminary treatment in which results in reducing the patient's burden. As a result, there is merit of detecting lung and other cancers at an early stage.
As for the upper abdomen, the patients have a choice between Upper gastrointestinal tract radiographic examination or the more precise endoscopy.
The MRI/MRA is recommended for examination of the head and the MRI is also recommended for the follow-up to the abdominal ultrasound test.
There is no radioactivity generated by the MRI, ultrasound or endoscopy. We also do not use the contrast for CT for normal examinations.
Blood draw markers are being developed for non-invasive early detection of cancer