Send to:

Choose Destination
See comment in PubMed Commons below
AJR Am J Roentgenol. 2014 Feb;202(2):318-23. doi: 10.2214/AJR.12.9676.

Patient-tailored scan delay for multiphase liver CT: improved scan quality and lesion conspicuity with a novel timing bolus method.

Author information

  • 11 All authors: Department of Radiology, University of California San Francisco, Box 0628, M372, 505 Parnassus Ave, San Francisco, CA 94143-0628.



The purpose of this study was to compare scan quality and lesion conspicuity for late arterial and portal venous phase liver CT scans using fixed versus patient-tailored scan delay derived with an evidence-based timing bolus method.


We retrospectively identified the cases of 73 patients who underwent both multiphase liver CT with fixed late arterial and portal venous phase scan delay times of 45 and 80 seconds and subsequent multiphase liver CT with patient-tailored scan delay determined with a timing bolus and a previously reported relation between the time to peak aortic and liver enhancement. Both late arterial and portal venous phase scans were graded in terms of scan quality. Hepatic lesion conspicuity (difference in attenuation between lesion and liver parenchyma) for hypervascular lesions (late arterial phase) and hypovascular lesions (portal venous phase) was recorded.


Patient-tailored scan delay reflected a wide range of times to peak aortic enhancement (mean, 24 seconds; range, 18-32 seconds) and yielded a greater proportion of optimal scans compared with fixed scan delay for both late arterial phase (92% versus 74%, p < 0.01) and portal venous phase (86% versus 70%, p < 0.05) scans. Mean hypervascular lesion conspicuity was greater for lesions imaged with patient-tailored scan delay rather than fixed scan delay (84.0 versus 57.0 HU, p < 0.01).


Compared with examinations with fixed scan delay, multiphase liver CT that incorporates patient-tailored scan delay produces more optimally timed late arterial and portal venous phase CT scans with greater lesion conspicuity.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Atypon
    Loading ...
    Write to the Help Desk