Minimize Pediatric And Small Patient Doses; Perform Only Necessary Ct Examinations; Scan Only The Organ Or Anatomical Region Indicated - GE Revolution CT User Manual

conditions for scanning. However, it is important to recognize that the dose reported by these
indices is inversely proportional to phantom size (see the above chart). This means that for the
same scan technique, smaller phantoms (patients) will produce a higher absorbed dose than
larger phantom (patients). Therefore, it is critical to remember that the body filter uses the 32 cm
CTDI phantom and the head filter uses the 16 cm CTDI (Computed Tomography Dose Index)
phantom for dose reporting purposes (CTDIvol is displayed in the
Scan Settings window). The table below indicates the phantom size used for calculating dose
for each SFOV (Scan Field Of View).
In other words, when looking at the actual absorbed dose to the patient, understand that the
dose may be higher than reported if the part scanned is smaller than the phantom tested. Keep
this in mind when adjusting scan parameters to fit patients who are smaller than the phantoms
tested.
Table 1: CTDI phantom used dose report based on SFOV type
Ped Head
Ped Body
Small Head
Head
Small Body
Medium Body
Large Body
Cardiac Small
Cardiac Medium
Cardiac Large

2.3 Minimize pediatric and small patient doses

There are several steps that can be taken to reduce the amount of radiation that pediatrics and
small patients receive from CT examinations. Everyone shares the responsibility of minimizing
CT radiation dose. Use the following suggestions for minimizing unnecessary doses.

2.3.1 Perform only necessary CT examinations

Is CT the most appropriate study? This important communication between the patient's
physician and the radiologist is essential in determining the need for the CT examination. The
indications and the appropriate technique to be used should be reviewed by the radiologist prior
to every scan including the patient's number of previous scans, reasons for the scan, and
consideration of other effective lower dose modalities. In all circumstances, the expected
benefits of the scan must always exceed the overall risk.

2.3.2 Scan only the organ or anatomical region indicated

Limit scan coverage to cover only the organ or anatomical region of the body indicated to avoid
unnecessary exposure.
Chapter 5 Pediatrics and Small Patients
SFOV type
Direction 5480385-1EN, Revision 1
Dose Information area on the
CTDI phantom
16 cm phantom
32 cm phantom
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