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Note: these are injector guidelines based on an
antecubital injection site. These guidelines may need
to be adjusted if the site is more peripheral.
Needle Size (gauge) Flow Rate (ml/sec)
22 1.5
20 2.0 – 3.0
18 3.0 – 5.0
Central lines and ports may need to be hand injected
or power injected at a very low flow rate (1 ml/sec).
PIC lines and 24 gauge (or smaller) lines are usually
hand injected. All of these protocols should be decided
on by your institution’s appropriate personnel.
8. Applications with 80 kV: For CTA protocols, the tube
voltage was set to 80 kV and the mAs values were
raised by a factor of 1.5 over the reduced 120 kV values.
This measure roughly reduces the dose by another
factor of 2. At a lower kV, substances with a high atomic
number (such as iodine) have a significantly higher CT
value (= vascular contrast). Iodine CT values at 80 kV
are about 50% higher than at 120 kV.
80 kV was also used for applications when the lowest
achievable mAs at 120 kV was still higher than neces-
sary for sufficient noise level (for technical reasons,
generators need to operate at a certain minimum
current for stable operation). For applications such
as neonate or airway scanning, the low tube output at
80 kV can be used to further reduce the dose to the
patient.
9. Please observe the recommended mAs settings in
the chronicle.
Note, that these recommendations are valid for the
default tube voltage of the specific protocol.
If the voltage is lowered from 120 kV to 80 kV sub-
stantially higher mAs values have to be used (at least
by a factor of 2).
Children