Periampullary Obstructive Disease: Bowel Preparation And LAVA Dynamic Enhanced MR Scan

Objective:To study the value of detection of the periampullay anatomy structure with LAVA sequence scanned with different bowel preparations such as adminstration hypotonic drug (654-2) only, oral contrast agent (water) only, or hypotonic drug combined with oral contrast agent.Materials and Methods:36 cases of healthy volunteers were randomly divided into three groups according to different bowel prepared methods including Group A with intermuscular injection of 654-2 only, Group B with drinking water only, and Group C with intermuscular injection of 654-2 combined with drinking water. All volunteers were scanned with SPGR T1WI sequence, and LAVA sequence before bowel preparation, with LAVA sequence after bowel preparation. An independent blinded analysis was performed by two abdominal imaging specialists. The MR imagings were scored with four grades according to the dilation of duodenal lumen dilation, the finding of duodenal mucosa and the periampullary structure such as common bile duct, ampullary and duodenal papilla. The value of detection of the periampullay anatomy structure with different bowel preparations combined with LAVA sequence were analyzed with rank sum test statistics.Results:The number of cases with duodenal lumen dilatation Grade 1 and 2 for different bowel preparation in Group A, B, C were 9 (from axial imaging)and 9 (from coronary imaging), 3 (from axial imaging)and 3(from coronary imaging), 10 (from axial imaging )and 10(from coronary imaging);P<0.05. The number of cases with periampullary structure Grade 1 and 2 for different bowel preparation in Group A, B, C were 10 (from axial imaging)and 9 (from coronary imaging), 3 (from axial imaging)and 3(from coronary imaging), 10 (from axial imaging)and 10(from coronary imaging);P<0.05. The number of cases with the finding duodenal mucosa Grade 1 and 2 for different bowel preparation in Group A, B, C were 3 (from axial imaging)and 3 (from coronary imaging), 10 (from axial imaging)and 9 (from coronary imaging),9 (from axial imaging)and 10(from coronary imaging);P<0.05.Conclusions:The value of detection of the periampullay anatomy structure with intermuscular injection of 654-2 combined with drinking water is prior to with intermuscular injection of 654-2 only or drinking water only in LAVA sequence .Part Two: Clinical CasesObjective::To analyze the diagnostic value of LAVA sequence with gadobenate dimeglumine dynamic contrast-enhanced combined with 654-2 and drinking water for.periampullary obstructive diseases, which MR imaging findings were descript.Materials and Methods:43 patients with ampullary obstruction disease were scanned with traditional MR sequences and LAVA dynamic contrast-enhanced (with gadobenate dimeglumine) sequence after intramuscular injection of 654-2 and drinking water. Then delayed scanning were performed at 6-8 min and 90 min after using intravenous injected contrast agent. An independent blinded analysis was performed by two abdominal imaging specialists for the MR imaging findings of periampullary obstructive diseases and the diagnosis value of these scanning methods.Results:Imaging features of choledocholithiasis included intraductal unenhanced nodules (94.1%, 16/17) and biliary distension (100%, 17/17). Imaging findings of periampullary tumor included biliary distension (100%, 19/19) and irregular thickened bile duct wall, soft tissue nodules, masses enhancement (89.5%, 17/19). The diagnosis sensitivity, specificity and accuracy of LAVA dynamic enhancement scanned combined bowel preparation were 94.1%, 100%, 97.7%, respectively, for the choledocholithiasis cases, and 94.7%, 95.8%, 95.3%, respectively, for the periampullary tumors.Conclusions:MRI LAVA dynamic enhanced scanned after bowel preparation can be used to improve the accuracy of MRI diagnosis for the periampullary obstructive disease.