4. The problem of dose in tomography

One of the most critical (and criticized) features of 3D reconstructions is that they require a large number of projections, and therefore a high dose absorbed by the patient. A few figures by way of example (in FBP):

• The effective dose of a chest CT scan is approximately that of 150 x-ray procedures (2 x-rays);

• The effective dose of a CT scan of the abdomen is approximately that of 250 x-ray procedures (2 x-rays);

• The effective dose of a heart scan is approximately that of 1,000 X-ray procedures (2 images);

• Globally, in the United States, CT represents only 5% of radiology procedures, but between 40% and 67% of the cumulative effective dose for the entire population!

Manufacturers of X-ray equipment (CT-scanner...