Objective:

To compare the value of dual-energy CT (DECT) and multi-slice spiral CT (MSCT) in evaluation on histodifferentiation of gastric cancer.

Methods:

From Sep. 2018 to Oct. 2019

115 cases of gastric cancer were selected in Yancheng First Peoples Hospital

who were diagnosed with gastric cancer by gastroscopy and underwent CT enhanced scanning before surgery

including MSCT enhancement 55 cases and DECT enhancement 60 cases randomly). The pathological results after operation were taken as the gold standard and these cases can be divided into poorly differentiated and intermediately/highly differentiated group respectively. Two independent sample t test methods were used to compare the difference of plain CT value

arterial CT value

venous CT value

arterial CT value added and venous CT value added between the two groups of gastric cancer under the MSCT mode. The differences of normalized iodine concentration and the slope （

a

/

v

） of the energy spectrum curve in the 40~70 keV interval in arterial and venous phase were compared between the two groups under the DECT enhancement mode. Meanwhile

receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of each parameter.

Results:

The venous CT value and venous CT value added were 97.818.94

92.008.00

61.887.50

56.526.86 in poorlydifferentiated and intermediately/highly differentiated groups. The normalized iodine concentration and the slope of energy spectrum curve were (21.571.98)%

(20.071.49)%

(58.752.91)%

(54.843.55)%

and -(3.200.25)

-(2.980.14)

-(3.710.30)

-(3.390.13) respectively in the two groups. The differences were statistically significant (

P

＜0.05). The area under curves (AUC) with the above parameters were 0.682

0.696

0.722

0.804

0.764 and 0.828. Combined with normalized iodine concentration and energy spectrum curves in the venous phase

AUC was 0.917

and the sensitivity and specific

ity were 0.862 and 0.871 when the appropriate threshold was selected.

Conclusion:

The normalized iodine concentration and energy spectrum curve of DECT can provide a new index for preoperative evaluation of the differentiation degree of gastric cancer

which is better than the traditional MSCT.