Operating instructions

65
Perfusion CT
IV injection protocol
Contrast medium Non-ionic
Concentration 300 – 370 ml
Injection rate 8 ml/sec.
Total volume 40 ml
Total injection time ~ 5 sec.
Start delay time 4 sec
The technique requires a short bolus. The original
studies were performed mostly using 50 ml injected at
10 ml/s.
The routine application has shown, that by sacrificing
some of the spatial resolution, the examination can also
be done with smaller amounts of contrast (35 to 40 ml)
and correspondingly smaller flow rates. The smaller the
total amount the more helpful it is to consider a saline
chaser bolus. In any case, a state-of-the-art power
injector is recommended.
If a flow rate of 8 ml/s is considered not recommen-
dable for a specific patient, the protocol can be reduced
to 40 ml at 5ml/s. Image quality will be reduced but
the technique will still be diagnostic.
• Additional measures to facilitate the injection, like
using a large gauge cannula (16 or 18 are usually
sufficient) and warming the contrast media to body
temperature to reduce its viscosity, should be con-
sidered.
Note: As with any contrast medium application,
verify that the particular models and brands that you
use in the chain injector/contrast medium/cannula
are approved by their respective manufactures for
the use with the parameters you select.
• Motion during acquisition must be avoided. There-
fore, if at all possible you should try to explain the
course of the examination to the patient and use
additional head fixation in any case.