Diagnostic value of CT perfusion imaging combined with markers of blood-brain barrier injuryin of sepsis associated encephalopathy

Abstract

Objective To explore the diagnostic value of CT perfusion imaging combined with markers of blood-brain barrier injury in sepsis-associated encephalopathy. Methods A total of 84 patients with sepsis were selected in the intensive medicine department from July 2015 to October 2017 and divided into observation and control groups according to the presence of sepsis-associated encephalopathy, there were 46 males and 38 females, aged 19-76(54.05±13.7). The serum levels of Occludin, nitric oxide synthase(NOS), neuron specific enolase(NSE), central nerve specific protein(S100β), glial fibrillary acidic protein(GFAP), and excitatory amino acids(EAA) were measured on the first and third day after admission. Brain CT perfusion imaging was performed to calculate regional cerebral blood flow(rCBF), relative cerebral blood volume(rCBV), and regional mean transit time(rMTT) in the region of interest(ROI). Serological and CT perfusion imaging parameters of the two groups were compared. T-test was performed for comparison between groups and within groups. The correlation between sepsis associated encephalopathy(SAE) and each indicator was analyzed by logistic regression analysis. The receiver operating characteristic(ROC) curve was used to analyze the clinical value of various variables in diagnosis of septic encephalopathy. Results The rCBF of patients in the observation group measured(45.63±16.56) and(34.83±15.64) mL·100 g-1·min-1 on the first and third day, respectively, which were lower than those of the control group at(63.61±16.61) and(56.34±15.74) mL·100 g-1·min-1. Statistically significant difference was observed(t=4.945, 8.003, both P=0.000). The rCBV on the first and third day reached(2.04±0.95) and(1.59±0.86) mL/100 g, respectively, which were lower than those of the control group(2.53±1.04) and (2.06±1.04) mL/100 g, presenting a statistically significant difference(t=2.234, 2.240, both P=0.028). The rMTT on the third day amounted to(3.92±0.93) s, which is higher than the(3.43±1.04) s of the control group, and the difference was statistically significant(t=2.254, P=0.027) . Three days after admission, the levels of occludin, NOS, NSE, S100β, GFAP, and EAA of the observation group reached (128.37± 15.61) ng/L, (56.04±10.54) U/mL, (23.03±4.96) mg/L, (0.29±0.05) µg/L, (125.39±37.83) ng/L, and (5.88±2.63) µmol/L, respectively, which were higher than those of the control group, which yielded values of (115.21±12.56) ng/L, (51.67±11.30) U/mL, (20.43±3.34) mg/L, (0.35±0.06) µg/L, (82.67±16.55) ng/L, and (4.73±1.05) µmol/L. Significant differences were observed between the two groups(t=4.282, 2.379, 2.858, 5.732, 10.351, 2.718, P=0.000, 0.020, 0.005, 0.000, 0.000, 0.008). Logistic regression analysis showed that the incidence of sepsis-associated encephalopathy was negatively correlated with rCBF(95%CI: 0.629-1.006, r=-0.624, P=0.037) and rCBV(95%CI: 0.010-1.174, r=-0.709, P=0.040) and positively correlated with occludin(95%CI: 1.011-1.553, r=0.722, P=0.039) and GFAP(95%CI: 1.005-1.154, r=0.688, P=0.035) levels on the third day. ROC curve analysis revealed that the area under the curve, with combined detection of rCBF + rCBV + occludin + GFAP, reached 0.939 on the third day. Conclusion The patients with sepsis showed a certain degree of neuronal injury in the early stage, and the combined detection of CT perfusion imaging and markers of blood-brain barrier injury presented a high diagnostic value for sepsis-associated encephalopathy. Key words: Sepsis; Sepsis associated encephalopathy; Tomography, X-ray computed; Perfusion imaging; Blood-brain barrier