[Biological relativity of imaging of CT perfusion for pancreases to pancreatic cancer].

OBJECTIVE

To explore the relationships between perfusion values of pancreatic cancers and the microvessel density of tumors (MVD) and vessel endothelial growth factor (VEGF), and the clinical value of multiple-slice spiral CT perfusion imaging in diagnosing pancreatic cancers.

METHODS

Forty-two people with normal pancreas and eighteen patients with pancreatic cancers underwent multiple-slice spiral CT perfusion examinations. The time-density curve (TDC) of the region of interest (ROI) was drawn with the software equipped in the spiral CT. The CT perfusion parameters of the ROI peak reinforcement values were calculated, including blood flow (BF), blood volume (BV), time to start (TTS), time to peak (TTP), permeability, and mean of the patlak blood volume (pBV). Twenty patients (11 with pancreatic cancers and 9 with chronic pancreatitis) were chosen for CD34 and VGEF antibody immunohistochemistry staining on the same layers of pancreatic tissues as the CT perfusion targeted. The associations between the imaging of CT perfusion and MVD and VFGF were examined.

RESULTS

The patients with pancreatic cancers had lower BF, VB, and pBV, and higher permeability than the normal controls (P<0.01). No differences appeared between the two groups in time to start and time to peak (P>0.05). The difference in average MVD of the 9 patients with chronic pancreatitis (13.8 +/- 9.6), and the 11 patients with pancreatic cancers (30.5 +/- 14.8) was statistically significant. Eight patients with pancreatic cancers showed strong positive VEGF and three showed weak positive VEGF. Only one patient with chronic pancreatitis showed strong positive VEGF while eight showed weak positive VEGF. The difference in positive rate of VEGF between the two groups of patients was statistically significant (P<0.01). The MVD in patients with pancreatic cancers (median 40.2) was correlated with BF (median 26.9), TTS (median 14.8), and TTP (median 145.3) (r=0.42, 0.63, and 0.45, respectively). The expression of VGEF (median 4.3) was negatively correlated with BV (r=-0.39).

CONCLUSION

Imaging of CT perfusion has certain clinical value for diagnosing pancreatic cancers. The imaging of CT perfusion reflects the MVD and VEFG in the tumor tissues.