European Radiology

, Volume 23, Issue 11, pp 3213–3218 | Cite as

Novel connecting tube for saline chaser in contrast-enhanced CT: the effect of spiral flow of saline on contrast enhancement

  • Masafumi KidohEmail author
  • Takeshi Nakaura
  • Kazuo Awai
  • Koji Yuba
  • Takayuki Kobayashi
  • Young-Kwang Park
  • Takanobu Yagi
  • Kazunori Harada
  • Yasuyuki Yamashita
Contrast Media



To evaluate the effect of a newly developed connecting tube, which generates a spiral flow of saline, on aortic and hepatic contrast enhancement during hepatic-arterial phase (HAP) and portal venous phase (PVP) computed tomography (CT).


Eighty patients were randomly assigned to one of two protocols: with a new or a conventional tube. The contrast material (600 mgI/kg) was delivered over 30 s; this was followed by the administration of 25 ml saline solution delivered at the same injection rate as the contrast material. Unenhanced and contrast-enhanced CT images of the upper abdomen were obtained. We calculated the changes in the CT number (∆HU) for the aorta during HAP and PVP, and for the liver during PVP. We compared ∆HU between protocols.


The mean ∆HU for the abdominal aorta during HAP was significantly higher with the new tube protocol than with the conventional tube protocol (322 ± 53 vs. 290 ± 53, P < 0.01). There were no significant differences in the mean ∆HU for the abdominal aorta and liver during PVP between the two protocols (P > 0.05).


The new connecting tube increased the effect of a saline chaser and significantly improved aortic enhancement during HAP.

Key Points

• Optimal administration of intravenous contrast material is essential for optimal CT quality.

• A new connecting tube can generate spiral flow, which improves intravenous administration.

• The new connecting tube improved aortic contrast enhancement during the hepatic-arterial phase.

• The new connecting tube increased the effect of a saline chaser.


Contrast-enhanced CT Saline chaser Contrast medium Contrast enhancement Spiral flow 



There was no direct financial support from industry for this study. This study received the connecting tube from Nemoto-Kyorindo, Tokyo, Japan, the manufacturer of the connecting tube used in this study. K.Y. is an employee of Nemoto-Kyorindo. Y.P. is chief executive officer of EBM, Tokyo, Japan. Y.P. and T.Y have pending and/or awarded patents for the subject matter described in the manuscript and receive royalty income for a patent license from Nemoto-Kyorindo. The authors (M.K, T.N, K.A, T.K, K.H, Y.Y) who were not employees of Nemoto-Kyorindo or EBM had control of data and information that might have presented a conflict of interest.

Supplementary material

Movie 1 (Electronic Supplementary Material

An image obtained by actually imaging the pushed state of the contrast agent using the new connecting tube. A black ink was mixed to the contrast agent. The saline flow rate was 4 ml/s. The pushed state was imaged by 500 frames per second using a high-speed camera. The portion appearing black in Movie 1 was the flow of the contrast agent. As understood from Movie 1, the new connecting tube was able to generate the spiral flow (MPG 2948 kb)


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Copyright information

© European Society of Radiology 2013

Authors and Affiliations

  • Masafumi Kidoh
    • 1
    • 2
    Email author
  • Takeshi Nakaura
    • 1
    • 2
  • Kazuo Awai
    • 3
  • Koji Yuba
    • 4
  • Takayuki Kobayashi
    • 5
  • Young-Kwang Park
    • 6
  • Takanobu Yagi
    • 6
  • Kazunori Harada
    • 7
  • Yasuyuki Yamashita
    • 2
  1. 1.Diagnostic RadiologyAmakusa Medical CenterAmakusaJapan
  2. 2.Department of Diagnostic Radiology, Graduate School of Medical SciencesKumamoto University 1-1-1HonjoJapan
  3. 3.Department of Diagnostic RadiologyHiroshima UniversityHiroshimaJapan
  4. 4.Sales Division, Nemoto KyorindoTokyoJapan
  5. 5.Kitasato Institute HospitalTokyoJapan
  6. 6.Faculty of Science and EngineeringWaseda UniversityTokyoJapan
  7. 7.Department of SurgeryAmakusa Medical CenterAmakusaJapan

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