The Clinical Features Of Spiral CT Perfusion Index In Patients With Acute Pancreatitis

OBJECTIVE This study was to investigate the technique of CT perfusion in healthy people and acute pancreatitis of human with Lightspeed VCT64row CT made by GE company and correlated with biochemistry markers (C-reactive protein, hematocrit, serum amylase, urine amylase, D-dimer, triglyceride) and clinical outcomes(APACHE II score, Ranson score, hospitalization time, abdominal pain relief time).METHODS A total of86cases and15healthy controls are included in this study from April in2010to March in2012. All patients undertook the procedure of CT perfusion test with the GE Lightspeed VCT64row CT after the admission for two or three days. The parameters are as follows, thickness5mm,8layers,120KV,60mA, distance between layers0, matrix512x512, speed1r/s. The scan begins after the contrast agent50ml (300mgI/ml) is injected, and the rate is4ml/s with the total dose50ml. The duration of the scan lasts for30s. The following CT perfusion parameters are computed by the soft ware of CT Perfusion4in ADW4.4system. Four parameters are obtained, blood flow (BF), blood volume (BV), mean time transit (MTT), permeability surface (PS) The sample of blood and urine are collected as soon as the scan finishes. The test includes serum amylase, urine amylase, C reaction protein, D-dimer, triglyceride and hematocrit. Also, Ranson score and APACHE Ⅱ are evaluated as well as admission time and abdominal pain relief time for Pearson correlation analysis.RESULTS The mean B V, BF,MTT,PS in acute pancreatitis (AP) are71.31±25.85(ml·100g-1·min-1)、15.20±4.31(mL/100g)、7.91±2.47(s)、42.21±13.82(ml·100g-1·min-1) respectively. BF and BV are significantly lower than healthy control (P=0.0047,0.0130), while the MTT and PS shows no significance(P=0.148,0.289). SAP (D grade and E grade in Balthazar score) showes the same tendency, in which BF and BV are significantly lower than MAP (A to C grade)(P<0.05), and the MTT and PS show no significance. In different age groups, the old group (>60y) is significantly lower in BF and BV, compared with the younger groups (<40y&41-60y)(P<0.05).The CRP, triglyceride, D-dimer and Hct in MAP are significantly lower than SAP (P=0.038、0.035、0.013、0.025), and the S-Amy and U-Amy don’t show significance. There is a relationship between the biochemistry markers and perfusion parameters and Hct and D-dimer are significantly correlated with BF and BV (r=-0.515, r=-0.624, P<0.05; r=-0.625, r=-0.584, P<0.05). The correlation analysis between perfusion parameters and clinical outcomes shows a significant correlationship between BF、BV and Ranson score, APACHE II score, abdominal pain relief time and admission time.CONCULUSION The perfusion in the pancreas is significantly decreased in acute pancreatitis and it is negatively correlated with the severity of the disease. CT perpusion can be helpful in diagnosis and evaluation of acute pancreatitis. BF and BV are can assist in evaluation of acute pancreatitis, while MTT and PS show no significance.