Impact of double-bolus tracking to individualize scan timing of the portal venous phase in preoperative computed tomography colonography angiography for right-sided colon cancer

TL;DR

A new method called double-bolus tracking improves the timing of scans in CT colonography for better imaging of blood vessels in right-sided colon cancer patients.

Contribution

The double-bolus tracking method individualizes scan timing, enhancing contrast and image quality in portal venous phase imaging.

Findings

CT values in the DBT group were significantly higher than in the fixed-delay group for multiple veins.

Visual assessment scores for the gastrocolic trunk were significantly better in the DBT group.

The DBT method improves contrast effect and image quality in portal venous systems.

Abstract

In computed tomography colonography angiography (CTC-A), used for preoperative screening of right-sided colon cancer, the timing of venous phase imaging is conventionally determined by a fixed-delay time; however, the contrast effect may be insufficient because of individual differences in blood flow status. Therefore, we developed the double-bolus tracking (DBT) method to solve this issue.

We compared the contrast effect and image quality of the portal venous systems between two methods of the conventional fixed-delay and DBT which utilizes low-dose monitoring to individualize venous scan timings. Data from 30 consecutive patients who underwent CTC-A for right-sided colon cancer using the DBT method were prospectively collected and compared with that from 30 consecutive patients who underwent the conventional fixed-delay method between August 2018 and July 2022. CT values of the portal vein, gastrocolic trunk, and middle colic veins were measured. Additionally, two gastrointestinal surgeons performed a five-point visual evaluation of the three-dimensional volume rendering image of the gastrocolic trunk.

CT values in the DBT group were significantly higher than those in the fixed-delay group. (portal vein: 266.7 HU vs. 210.0 HU; p <  0.001, gastrocolic trunk: 251.6 HU vs. 191.0 HU; p <  0.001, middle colic vein: 257.2 HU vs. 190.1 HU; p <  0.001). Visual assessment of the gastrocolic trunk was significantly higher in the DBT group than that in the fixed-delay group (DBT, 3.6, 3.4; fixed-delay, 2.6, 2.8; p =  0.003, p =  0.044).

The DBT method can enhance the contrast effect of the portal venous systems and improve image quality.

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