Radiotherapy<unk>  is used in radiation therapy planning to reduce doses to healthy organs such as the heart or lungs. Most radiation therapy is planned using the results of a 3D CT scan. A 3D scan largely presents a snapshot of the body at a particular point in time, however due to the time of the acquisition, in which the patient is likely to have moved in some way (even if only breathing), there will be an element of blurring or averaging in the 3D scan. When it comes to treatment planning, this motion can mean there is less accuracy in the positioning of treatment beams, and reduce the likelihood of a repeatable set-up on the linear accelerator when it comes to treatment. To minimise physical movements of the patient, some sort of immobilisation is typically used. To overcome physiological motion, such as breathing,<unk>  acquires images at a range of times and positions, allowing the extent of motion to be visualised (e.g. from maximum inspiration to maximum exhalation). The treatment plan can then be designed with a knowledge of the full range of possible positions of important organs, and the tumour (target) itself.<unk>  will usually involve a gating technique, such as breathing tracking, so that image acquisition is automatically triggered at set points. This gating can also be applied at treatment, where the radiotherapy beam is only switched on at certain points in the breathing cycle (as in the deep inspiration breath-hold technique). Diagnostic radiology<unk>  has started to be used for diagnostic radiology procedures, for example looking at joint problems, the cardiac cycle and parathyroid washout of contrast. Downsides of<unk>  for diagnostic purposes include large and complex datasets, and increased radiation dose to the patient.
4DCT
PAIR 
SNOMED CT
Radiomics
Medicine chest
Medicine chest 
Tomosynthesis
X-ray