| Objective: To explore and study the display capabilities of3.0T magnetic resonance onvisualization the vitro small intestinal wall layers of the canine, and to analyze the signalcharacteristics of the layers.Materials and methods: Seven in vitro specimens of the canine small intestine werescanned using clinical3.0T MR and eight channel phased array head receive coil. Thesequences used were T1-weighted fast spin echo with fat saturation and T2-weighted fastspin echo with fat saturation. There are three specimens of duodenum, two specimens ofjejunum and two specimens of ileum. The specimens were placed in a container filled withthe solution of ferric ammonium citrate. The specimens were scanned three hours after thetissue was separated from a beagle. To observe the number of the small intestinal walllayers, the signal characteristics of T1WI and T2WI, and compare with histopathologicalresults of the specimens.Results: On T1WI images, four different intestinal wall layers were observed, of which thesignal intensity was isointensity, low signal intensity, high signal/low signal intensity fromthe inside to outside of the intestinal wall; On T2WI images, three layers were visible, and the signal intensity was high signal intensity, low signal intensity, and high signal intensity.Due to histopathological correlation, three layers were depicted from inside to outside ofthe intestinal wall as follows: mucosa, submucosa and musculars on T1WI and T2WI; thefourth layer was serosa on T1WI. On T1WI and T2WI images, the signal intensity ofsubmucosa is generally lower than that of mucosa and muscular, and CNR of submucosa isstatistically different with that of mucosa and musculars.Conclusion:3.0T magnetic resonance with the head receive coil can distinctly display thevitro small intestinal wall layers, T1WI and T2WI can show three or four layers of smallintestinal tissue. Objective: To investigate the appearance of small intestine wall layers of the normalcanine on clinical3.0T MR and to compare with the histopathological results.Materials and methods: Randomly select five normal Beagles, fasting for12-24hoursbefore scanning, water deprivation for6-8hours, then accept3.0T MR scan, with TORSObody coil, T2-weighted fast spin echo with or without fat saturation, respiratory triggered,the thickness3mm, matrix288x288. Sacrifice one beagle dog by overdose anesthetic agent,and take tissue samples of duodenum, jejunum and ileum for HE and Masson staining.Analysize MR images and histopathological images analysis, record the number of smallintestine intestinal wall layers, thickness and signal intensity of each layer and compareMR appearance with histological results, by statistical analysis of single factor analysis ofvariance and Pearson correlation analysis between MR images and histological findings.Results: On T2WI images，duodenum and jejunum can be shown four different layers of,of which the signal intensity was isointesnsity, high signal intensity, low signal intensityand isointensity from inside to outside of the small intestinal wall. The inner two layers iscorresponding to histological mucous; the outer two layers is the submucosa andmuscularis. On T2WI images, ileum can be seen three different layers, mucous layershowed high signal, submucosa showed low signal, muscularis were isointensity. There aregood correlation between MR images and histopathology results.Conclusion:3.0T magnetic resonance can distinctly display the vivo small intestinal walllayers, and MR images are in good agreement with histopathology. Objective: Analyse the performance of small intestinal wall of mesenteric ischemia on thebasis of appearance of normal small intestinal wall layers of beagle dogs. Explore thediagnostic value of magnetic resonance on the small intestinal wall ischemia after acutemesenteric ischemia for early diagnosis of mesenteric ischemia.Materials and Methods:9beagle dogs were randomly divided into three groups, eachgroup had three, namely ischemia1h group, ischemia3h group and ischemic6h group.Superior mesenteric artery (SMA) angiography was made by the DSA, then embolize partsof the jejunum and ileum artery branch by gelatin sponge and clot. Respectively after1h,3h,6h, MR scanning was carried out with T2-weighted fast spin echo with or without fatsaturation. Obtain histological specimens of the ischemic bowel after the end of the scanfor HE and Masson staining, and examination of the electron microscope.Results:9experimental beagle dogs were successfully established ischemic model of acutemesenteric ischemia. The bowel wall ischemic changes were observed on T2WI images.The degree of bowel wall ischemia was progressively increased as the ischemic timeprolonged. MR appearance of ischemia1h group mainly showed that mucous layer contourwas visible or part of the layer was incomplete, the signal of mucosal layer was increased,or a ring of uniform high signal in mucosal layer can be seen, the structure and signal ofsubmucosa and muscular were normal. MR appearance of ischemia3h group mainlyshowed uniform or slightly mixed high signal in the mucosal layer, and submucosa andmuscular were normal. MR appearance of ischemia6h group showed that the normalcontour of mucosal layer was disappeared, a mixed high signal can be seen in mucosallayer, parts of the structure of submucosa were incomplete and the signal of muscularisincreased. Ischemia1h group and3h group mainly displayed the changes of mucous layer structure and the signal, and submucosa and muscular structure were involved in ischemia6h group. There was good consistency between MR images and histopathology results.Conclusion: MR images can clearly display the changes of the small intestinal wallischemia, and make a diagnosis of ischemic intestine in the early stage. |
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