J Korean Radiol Soc.  1999 Jun;40(6):1159-1164. 10.3348/jkrs.1999.40.6.1159.

Optimal Scan Time of Dual-phase Spiral CT in Normal Rabbit Liver: Effect of Contrast Injection Rate

• Kwak BK
• Kim SH
• Liu WC
• Kim SA
• Woo JJ
• Hong JH
• Kim SY
• Bae KH
• Kim CS
• Yang SJ
• Shim HJ
• Jeong HS

• KMID: 2200941
• DOI: http://doi.org/10.3348/jkrs.1999.40.6.1159

Abstract

PURPOSE: To determine the effect of contrast injection rate on rabbit liver enhancement and the optimaltem-poral window for dual-phase spiral CT of rabbit liver at each injection rate.
MATERIALS AND METHODS
Usingspiral CT, seven New Zealand White rabbits underwent dynamic scanning at one level of liver. Three protocols ofcontrast injection rates were employed, namely 0.3 ml/sec(group 1), 1ml/sec(group 2) and 2 ml/sec(group 3). During120 seconds of total scan time, the scan interval was 3 seconds. Densities of the aorta, liver and portal veinwere averaged in equivalent time. The different injection rate protocols were compared for peak enhancement/timeon a time density curve.
RESULTS
Mean peak enhancement (HU) in equivalent time(secs) was 310/18(group 1),383/9(group 2) and 357/6(group 3) in the aorta ; 34/36, 40/36 and 41/30 in the liver ; and 135/36, 153/24 and170/21 in the portal vein. The temporal window during the arterial phase was 12-21 sec(group 1), 6-12 sec(group2), and 6-12 sec(group 3). The temporal window during the portal phase was from 30 sec(0.3ml/sec), 21sec(1ml/sec)and 21 sec(2 ml/sec).
CONCLUSION
During dual-phase spiral CT, the temporal window for liver scanningshould be determined according to each contrast injection rate. A slow contrast injection rate prolongs thetemporal window during the arterial phase.

Keyword

Computed tomography(CT), helical; Contrast media, experimental studies; Liver, CT

MeSH Terms

Aorta
Liver*
Portal Vein
Rabbits
Tomography, Spiral Computed*