The Diagnostic Value Of GRE-T2* Weighted Imaging For Acute Pancreatitis

Objective: To quantitatively analyze T2* values of the head, body, and tail of normal pancreas.Methods: A total of 51 subjects with normal pancreas were included. T2* value were measured on T2*WI obtained with 16 echoes gradient recalled echo(GRE) sequence on the head, body and tail of normal pancreas, and were compared among those the three parts of pancreas, between different gender and among different ages groups, and the correlation of T2* value among those three parts of pancreas were analyzed.Results: The average T2* value of the head, body and tail of normal pancreas were(22.74±3.45) ms,(20.51±3.40) ms,(19.92±3.90) ms, respectively. There are no statistical differences between different gender and age groups(all P >0.05). T2* value was the obvious statistical significance difference between the head and body(t=3.59, P<0.01), as well as between the head and tail(t=4.30, P<0.01). But no statistical difference was found between the body and tail of pancreas(t=1.30, P=0.20). The T2* value had no correlation between the head and body(r=0.19, P=0.18), nor between the head and tail(r=0.15, P=0.32), but there is the obvious correlation between the body and tail(r = 0.50, P <0.01).Conclusions: T2* values of the head, body and tail of pancreas are preliminarily identified the normal pancreatic head, body and tail of the T2* value with MR GRE-T2*WI, which may provide references for the clinical diagnosis and research of pancreatic diseases.Objective: To study gradient recalled echo(GRE) T2* weighted imaging(T2*WI) for the normal pancreas and acute pancreatitis(AP).Methods: Fifty one patients without any pancreatic disorders(Control group) and 117 patients with clinically proved AP were recruited in this study. All patients had performed MRI with conventional sequences and T2* weighted imaging at 3.0T MR scanner. The T2* values of the head, body and tail of pancreas were respectively measured in both AP group(If AP with necrosis, measuring the corresponding to the area without necrosis) and Control group. The severity of AP was graded by MR severity index(MRSI) and the Acute Physiology And Chronic Healthy Evaluation II(APACHE II) scoring system. The relationship of T2* values with MRSI and APACHE II were analyzed.Results: On the T2*WI, the features of pancreas is well-marginated and consistently homogeneous iso-signal intensity. In AP group, the feature of pancreas is ill-defined and the pancreatic signal intensity is homogeneous in edematous pancreatitis, as well as in the area without necrosis in the necrotizing pancreatitis. When AP with pancreatic hemorrhage can result in decrease of the T2* value and the signal loss on the signal decay curve. The average T2* value of pancreas is(25.86±4.90) ms, which is higher than that of Control group(t=-8.20, P<0.01). There was a significant difference for the T2* value in the AP patients between with and without pancreatic necrosis(P<0.05). According to MRSI, the T2* values were significant difference between mild and moderate AP, mild and severe AP(P<0.05), except for between the moderate and severe AP(P>0.05). There was no significant difference for pancreatic T2* value between the mild and severe AP according to the APACHE II(P>0.05).Conclusions: T2*WI demonstrated some characteristics of the normal pancreas and AP, and may do some contributions to the diagnosis of AP, detection the pancreatic hemorrhage and determining the severity of AP.