J Vet Sci.  2016 Dec;17(4):555-561. 10.4142/jvs.2016.17.4.555.

Optimal scan delay depending on contrast material injection duration in abdominal multi-phase computed tomography of pancreas and liver in normal Beagle dogs

• Choi SY
• Lee I
• Seo JW
• Park HY
• Choi HJ
• Lee YW

• KMID: 2412612
• DOI: http://doi.org/10.4142/jvs.2016.17.4.555

Abstract

This study was conducted to establish the values for optimal fixed scan delays and diagnostic scan delays associated with the bolus-tracking technique using various contrast material injection durations in canine abdominal multi-phase computed tomography (CT). This study consisted of two experiments employing the crossover method. In experiment 1, three dynamic scans at the porta hepatis were performed using 5, 10 and 15 sec injection durations. In experiment 2, two CT scans consisting of five multi-phase series with different scan delays of 5 sec intervals for bolus-tracking were performed using 5, 10 and 15 sec injection duration. Mean arrival times to aortic enhancement peak (12.0, 15.6, and 18.6 sec for 5, 10, and 15 sec, respectively) and pancreatic parenchymal peak (17.8, 25.1, and 29.5 sec) differed among injection durations. The maximum mean attenuation values of aortas and pancreases were shown at the scan section with 0 and 5, 0 and 10 and 5 and 10 sec diagnostic scan delays during each injection duration, respectively. The optimal scan delays of the arterial and pancreatic parenchymal phase in multi-phase CT scan using fixed scan delay or bolus-tracking should be determined with consideration of the injection duration.

Keyword

bolus-tracking technique; computed tomography; dogs; injection duration; scan delay

MeSH Terms

Animals
Contrast Media/*chemistry
Dogs
Female
Injections, Intravenous/veterinary
Iohexol/*chemistry
Liver/*diagnostic imaging
Male
Pancreas/*diagnostic imaging
Radiographic Image Interpretation, Computer-Assisted/*methods
Tomography, X-Ray Computed/*veterinary
Contrast Media
Iohexol

Figure

• 

  Fig. 1 Diagram for a concept of bolus-tracking technique. In transverse CT images of the level of the L3–4 intervertebral space, the region of interest (dotted circle) was placed at the aorta (A), and the attenuation value measured continuously after contrast injection. The scan start was triggered automatically when the attenuation value of the aorta arrived at a desired value (B).

• 

  Fig. 2 The change curves of mean attenuation values at the aorta (A), pancreatic parenchyma (B), portal vein (C), and liver parenchyma (D) versus scan delays of 5 sec after automatic triggering by the bolus-tracking technique with the injection durations.

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  Fig. 3 Transverse CT images of pancreatic body level obtained using 5 sec scan delay after triggering by the bolus-tracking technique with 5 (A), 10 (B), and 15 (C) sec injection durations in a Beagle dog. Note the difference in pancreatic parenchymal contrast enhancement (arrows) by the injection duration of contrast material.

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