ABSTRACT
Objective To study the portal venous systemic thrombosis (PVST) in early acute pancreatitis (AP) and its correlations with the classification and severity of AP. Methods A total of 396 patients with AP were admitted to the affiliated hospital of north sichuan medical college from January 2013 to May 2017 and underwent MRI in the early stage of AP. PVST was evaluated on the T1WI, T2WI fat-suppression, and dynamic-enhancement sequences. Evaluating the MR imaging, AP was graded as mild, moderate, and severe AP based on the MR severity index (MRSI) and was also classified into interstitial edematous AP and necrotizing AP. According to the New Revised Classification of AP 2012, AP in the clinic setting was graded as mild, moederately severeand severe AP. χ2 test or Fisher exact test calculated the differences of the prevalence of PVST in different severity and classification of AP, Mann-Whitney U test calculated the difference of hospitalization time between patients with PVST and those without PVST. Results Among the 396 patients with AP, PVST was detected in 30 patients (7.5％,30/396), it formed most frequently in splenic vein(73.3％, 22/30), followed by portal (30.0％, 9/30) and superior mesenteric(16.7％, 5/30) veins. According to MRSI, there were 205, 177, and 14 patients with mild, moderate, and severe AP, respectively;among mild, moderate, and severe AP, there were 2, 21, and 7 patients with PVST, respectively (χ2=41.455, P<0.01), there were also statistical differences in the prevalence of portal and splenic vein thrombosis (P<0.05), but there was no statistical difference in the prevalence of superior mesenteric vein thrombosis (P>0.05). Three hundred and eleven patients had interstitial edematous AP and 65 patients had necrotizing AP, among which there were 11 and 19 patients with PVST(χ2=48.447,P<0.01), the prevalence of portal, splenic and superior mesenteric vein thrombosis in necrotizing AP were all higher than that in interstitial edematous AP (P<0.05). Based on the New Revised Classification of AP 2012, there were 194, 184 and 18 patients with mild, moderately severe, and severe AP, respectively; among mild, moderately severe, and severe AP, there were 0, 25, and 5 patients with PVST, respectively (χ2=42.130, P<0.01), there was no statistical differences in the prevalence of portal, splenic and superior mesenteric vein thrombosis (P>0.05). Patients with PVST and those without PVST in the early AP, the hospitalization time [median (interquartile range)] were 18 (13 to 22) days and 13 (10 to 19) days (Z=-2.913, P=0.004). Conclusion PVST in early AP presented more frequently with the increase in severity of AP based on both the MRSI and Newly Revised Classification of AP 2012, along with longer duration ofhospitalization.
ABSTRACT
Objective To investigate the dynamic changes of blood-brain barrier(BBB) permeability after acute cerebral ischemia in rats with middle cerebral artery occlusion (MCAO) by dynamic contrast-enhanced(DCE)-MRI. Methods Sixty MCAO rat models were established by suture-occlusion method. All rats were divided randomly into twelve groups with different ischemia duration (3 hours, 6 hours, permanent) and reperfusion times (2, 6, 12 and 24 hours after reperfusion). Each group was examined by MRI at the time points. The BBB permeability parameters(Ktrans, Ve, Kep, rKtrans, rVe, rKep) were calculated by Siemens workstation and compared with Evans blue(EB) extravasation results. Multivariate analysis of variance (M-ANOVA), one-way analysis of variance (one-way ANOVA), Pearson analysis were respectively used to verify the influences of ischemia duration and reperfusion time on BBB permeability parameters, EB extravasation and relationships between parameters. Results In 3 hours and 6 hours ischemia duration groups, change of BBB permeability after reperfusion appeared biphasic. At 2 hours and 6 hours after reperfusion, BBB permeability increased, while rKtrans values and rVe values rose and rKep values dropped. BBB permeability decreased at 12 hours and increased again at 24 hours after reperfusion. The highest BBB permeability was observed at 6 hours after reperfusion. However, BBB permeability in permanent ischemia groups had uniphasic change, as its increase was rather mild as ischemia time went on. rKtrans values(1.99± 0.79)were positively correlated with rVe values(2.88 ± 1.78) (r=0.93, P<0.01) and negatively correlated with rKep values(0.66 ± 0.21) (r=-0.84, P<0.01). The negative correlation between rVe values and rKep valueswas also significant(r=- 0.80, P<0.01). EB extravasation results were consistent with MRI findings. Conclusions BBB permeability change was biphasic in reperfusion groups, while it was uniphasic in permanent ischemia groups. DCE-MRI may accurately reflect the changes of BBB permeability after acute cerebral ischemia. Both ischemic duration and reperfusion time had influences on BBB permeability. With prolongation of ischemic time, the duration of BBB permeability increase became shorter, BBB damage appeared earlier, with increased degree of ischemic damage.
ABSTRACT
Objective To evaluate the value of magnetic source imaging(MSI) in localizing the epileptic foci of patients with histologically proved grey matter heterotopia(GMH) and seizure. Methods MSI examinations were performed on 8 patients with GMH and seizure. The location of the epileptic foci defined by MSI was compared with the results of the ECoG. After imaging examinations, all patients received operation with 13-48 months follow up to observe the effectiveness of the operation. Results Among the 8 patients, 1 had hippocampal sclerosis,2 had focal cortical dysplasiaof type Ⅰ B and 1 had focal cortical dysplasia of type Ⅱ B. MRI showed normal findings in 2 cases, subcortical heterotopia in 4 cases, and nodulor heterotopia in 2 cases with one having schizencephaly. The epileptic foci defined by MSI were at right temporal lobe in 2 cases, left frontal lobe in 2 cases, biparietal lobe in1 case, left parietal lobe in 1 case, left temporal lobe in 1 case, and left frontal-parietal lobe in 1 case. The epileptic foci defined by MSI were completely overlaid with area of GMH in 4 cases, closely behind the area of GMH in case, and partly overlaid with area of GMH in 1 cases with size larger than that of the latter. One patient showed two epileptic foci with one located within the area of GMH and the other one 2 centimeters anterior to the area of GMH.One case's epileptic focus located 2 centimeters posteolateral to the area of GMH . The locations of the epileptic foci defined by MSI showed no difference with those defined by ECoG in all patients. According to Engel classification of treatment effect of epilepsy, 6 patients achieved Engle class Ⅰ ( seizure free after operation ), and 2 patients Engel class Ⅳ ( no changes in the frequcenty of occurrence of seizures before and after operation ). Conclusion MSI can noninvasively and precisely localize the epileptic foci before operation in patients with GMH and seizure.