Application value of wide detector CT target scanning technique in the preoperative evaluation of pancreatic cancer / 中华胰腺病杂志

ABSTRACT

Objective:To explore the application value of wide detector multi-slice spiral CT target scanning technique in the preoperative evaluation of pancreatic cancer.Methods:The clinical data of 22 patients with pancreatic cancer who underwent pancreatic arterial contrast enhanced CT scanning and were diagnosed by pathology in the First Affiliated Hospital of Naval Medical University from September 2019 to October 2019 were analyzed retrospectively. The CT phantom experiment was carried out on the international standard phantom CATPHON500. By changing the scanning radiation dose, scanning mode and scanning field of view, the spatial resolution and density resolution of the image were compared and analyzed. The target scan technical parameters obtained from the experiment were applied to the late arterial phase of MDCT enhanced scan in 22 patients with pancreatic cancer. Executive current, volume scanning mode and small scanning field were used for scanning. The attenuation value (CT value) and noise value (SD value) of pancreatic cancer tissue and normal pancreatic tissue were measured at different phases, the attenuation difference and contrast signal-to-noise ratio (CNR) of the two tissues were calculated, the contrast difference between the two tissues was evaluated, and the CT values of celiac trunk, renal artery and vein, superior mesenteric artery and vein, splenic vein and portal vein were measured, and the display of tumor tissue and peripancreatic important vessels was evaluated.Results:In the phantom experiment, under the condition of the same radiation dose, the image quality of the volume scan mode was better than that of the spiral scan mode (1%@4 mm versus 1%@9 mm at 5 mGy and 1%@2 mm versus 1%@6 mm at 25 mGy). In comparison between pancreatic tumor and pancreatic tissue, the enhancement process of pancreatic tumor tissue was increased at first and then decreased, while that of pancreatic tumor tissue was slightly enhanced. The attenuation difference between pancreatic tissue and tumor tissue and CNR also increased at first and then decreased, reaching the maximum at the late arterial stage [(91.96±29.29)HU, 8.60±5.71]. The differences between each phase were statistically significant ( F values were 47.20 and 19.80 respectively, all P values <0.05). The evaluation of vascular variation and invasion showed that a better arterial phase image could be obtained on the late arterial target scan images, while taking into account the display of splenic vein, mesenteric vein and portal vein. Conclusions:The wide detector MDCT target scanning technique can improve the spatial resolution and density resolution of the image, greatly improve the contrast between tumor tissue and peripancreatic tissue and blood vessels, and provide more accurate tumor staging and resectability evaluation information for preoperative evaluation of pancreatic cancer.