Hepatic spiral CT: reduction of dose of intravenous contrast material.
OBJECTIVE
To assess the potential for reduction of contrast material dose in hepatic spiral computed tomography (CT).


METHODS
Four hundred eighty-seven outpatients were randomized prospectively into nine biphasic and eight uniphasic injection protocols: 75, 100, or 125 mL of 240, 300, or 350 mg of iodine per milliliter of iohexol (18-44 grams of iodine). Protocols were compared according to the maximum hepatic enhancement (MAX) and the contrast enhancement index (CEI).


RESULTS
Uniphasic injection was superior to biphasic injection for all protocols. No statistically significant difference in contrast enhancement was present for 38-44 grams of iodine with the uniphasic technique. Adequate enhancement thresholds (MAX > 50 HU, CEI at 30 HU > 300 HU x sec) were exceeded in more than 70% of heavy patients ( > 183 lb [83 kg]) with uniphasic injection of 38 g. For thin patients ( < 183 lb [83 kg]), uniphasic injection of 26 g produced adequate enhancement.


CONCLUSIONS
Contrast material dose may be reduced by up to 40% in thin patients undergoing hepatic spiral CT after uniphasic injection of contrast material; this may result in substantial cost savings.
Brink
J A
JA
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO 63110, USA.
Heiken
J P
JP
Forman
H P
HP
Sagel
S S
SS
Molina
P L
PL
Brown
P C
PC
D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage*; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D007472:Iohexol