Fig 1.
Scanning protocol for DBT and fixed-delay methods.
DBT, double-bolus tracking.
Fig 2.
Venous vascular measuring point.
(a) The portal vein at the hepatic hilum. (b) The root of the gastrocolic trunk (GCT) draining into the superior mesenteric vein (SMV). The root of the inferior mesenteric vein (IMV) draining into the splenic vein (SPV) or the SMV. (c) The root of the middle colic vein (MCV) draining into the SMV. (d) Three-dimensional volume rendering (3D-VR).
Table 1.
Patient characteristics.
Fig 3.
Venous phase scan timing, computed tomography (CT) values, and the contrast-to-noise ratio (CNR) in the double-bolus tracking (DBT) method compared with the conventional fixed-delay method.
(a) Cumulative histogram showing the trigger delay in the DBT method (range, 20.4–27.6 s; median, 23.4 s). (b) (c) Bar graph showing the comparison of CT value and CNR for the portal, gastrocolic, middle colic, and inferior mesenteric veins between the DBT and fixed-delay groups (mean ± standard error, * p < 0.001).
Table 2.
Differences in the CT values and contrast-to-noise ratios.
Fig 4.
Image quality scoring of three-dimensional volume rendering (3D-VR) images evaluated using a five-point scale by two blinded surgeons.
Image quality is scaled as follows: 1) nondiagnostic (no GCT delineated), 2) poor (only the base of the GCT delineated), 3) acceptable (the distal portion of the GCT delineated), 4) good (terminal branches of the GCT delineated), and 5) excellent (terminal branches of the GCT clearly delineated). a and b represent the results of each surgeon. Comparison of the number of each score and the average of those scores (mean ± standard error).
Fig 5.
Representative three-dimensional volume rendering (3D-VR) images of transverse colon cancer.
(a) The 3D-VR images obtained using the double-bolus tracking (DBT) method clearly show the gastrocolic trunk (GCT) consisting of the accessory right colic vein (ARCV) and right gastroepiploic vein (RGEV). (b) The 3D-VR images obtained using the conventional fixed-delay method do not clearly visualize the GCT. (c) Fused image of arteries and veins without mis-registration used in surgical simulation. The relationship between the middle colic artery (MCA), middle colic vein (MCV), accessory right colic vein (ARCV), and pancreas is clear.