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Timing of parenchymal enhancement on dual-phase dynamic helical CT of the liver: how long does the hepatic arterial phase predominate?

Publication ,  Journal Article
Frederick, MG; McElaney, BL; Singer, A; Park, KS; Paulson, EK; McGee, SG; Nelson, RC
Published in: AJR Am J Roentgenol
June 1996

OBJECTIVE: Dual-phase dynamic helical CT is now being used to detect and characterize benign and malignant hypervascular lesions in the liver. The purpose of this study is to define the timing and degree of parenchymal enhancement of normal liver during the hepatic arterial phase. SUBJECTS AND METHODS: This prospective study included 102 patients with known or suspected hypervascular hepatic lesions who underwent dual-phase helical CT. After unenhanced CT scanning, we injected iopamidol (Isovue 300; Bracco Diagnostics, Princeton, NJ) at 3 ml/sec for 120 ml, then at 2 ml/sec for 55-60 ml. Scan delay for the hepatic arterial phase was 25 sec and for the portal venous phase was 76 sec. Section thickness was 7 mm and pitch was 1:1. Operator-defined regions of interest were obtained from all three phases. RESULTS: Mean unenhanced attenuation of the liver was 51 +/- 12 H. The liver revealed progressive enhancement during the hepatic arterial phase as follows: an increase of 10 H occurred at a mean time of 33 +/- 4 sec, 20 H at 39 +/- 6 sec, 30 H at 44 +/- 8 sec, 40 H at 46 +/- 6 sec, and 50 H at 48 +/- 5 sec. At 20 H and 30 H of enhancement, we found a statistically significant difference (p < .01) for the mean times of men and women. Mean peak enhancement during the portal venous phase was 89 +/- 23 H. CONCLUSIONS: Because the hepatic arterial contribution to liver perfusion is approximately 30%, parenchymal enhancement greater than approximately 30% of peak might indicate portal venous predominance. In our study, this percentage corresponded to an increase of approximately 30 H. Therefore, detection of hypervascular lesions in the hepatic arterial phase may be compromised when imaging lasts longer than approximately 44 sec after the initiation of contrast material injection because 44 sec was the mean time for 30 H of enhancement in our series. However, variability between patients was marked, particularly between men and women. Furthermore, the data suggests that the hepatic arterial phase may be relatively brief and that it may be difficult to image properly using current helical CT technology.

Duke Scholars

Published In

AJR Am J Roentgenol

DOI

ISSN

0361-803X

Publication Date

June 1996

Volume

166

Issue

6

Start / End Page

1305 / 1310

Location

United States

Related Subject Headings

  • Tomography, X-Ray Computed
  • Retrospective Studies
  • Radiographic Image Enhancement
  • Prospective Studies
  • Nuclear Medicine & Medical Imaging
  • Middle Aged
  • Male
  • Liver Circulation
  • Liver
  • Iopamidol
 

Citation

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MLA
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Frederick, M. G., McElaney, B. L., Singer, A., Park, K. S., Paulson, E. K., McGee, S. G., & Nelson, R. C. (1996). Timing of parenchymal enhancement on dual-phase dynamic helical CT of the liver: how long does the hepatic arterial phase predominate? AJR Am J Roentgenol, 166(6), 1305–1310. https://doi.org/10.2214/ajr.166.6.8633437
Frederick, M. G., B. L. McElaney, A. Singer, K. S. Park, E. K. Paulson, S. G. McGee, and R. C. Nelson. “Timing of parenchymal enhancement on dual-phase dynamic helical CT of the liver: how long does the hepatic arterial phase predominate?AJR Am J Roentgenol 166, no. 6 (June 1996): 1305–10. https://doi.org/10.2214/ajr.166.6.8633437.
Frederick MG, McElaney BL, Singer A, Park KS, Paulson EK, McGee SG, et al. Timing of parenchymal enhancement on dual-phase dynamic helical CT of the liver: how long does the hepatic arterial phase predominate? AJR Am J Roentgenol. 1996 Jun;166(6):1305–10.
Frederick, M. G., et al. “Timing of parenchymal enhancement on dual-phase dynamic helical CT of the liver: how long does the hepatic arterial phase predominate?AJR Am J Roentgenol, vol. 166, no. 6, June 1996, pp. 1305–10. Pubmed, doi:10.2214/ajr.166.6.8633437.
Frederick MG, McElaney BL, Singer A, Park KS, Paulson EK, McGee SG, Nelson RC. Timing of parenchymal enhancement on dual-phase dynamic helical CT of the liver: how long does the hepatic arterial phase predominate? AJR Am J Roentgenol. 1996 Jun;166(6):1305–1310.

Published In

AJR Am J Roentgenol

DOI

ISSN

0361-803X

Publication Date

June 1996

Volume

166

Issue

6

Start / End Page

1305 / 1310

Location

United States

Related Subject Headings

  • Tomography, X-Ray Computed
  • Retrospective Studies
  • Radiographic Image Enhancement
  • Prospective Studies
  • Nuclear Medicine & Medical Imaging
  • Middle Aged
  • Male
  • Liver Circulation
  • Liver
  • Iopamidol