| BackgroundThe small intestine is the main place of human digesting food and absorbing nutrition, is the longest period of muscular conduits in the gastrointestinal tract, it meanders, overlapping, adult’s small intestine is about5～7meters long, can be divided into the duodenum, jejunum and ileum.The special anatomical structure of small intestine brings certain difficulty to the examination and diagnosis of the small intestinal lesions. The diagnosis of small intestinal lesions mainly depends on imaging study. Oral barium small bowel imaging is the most common and the easiest way to observe the small intestinal mucosa, intestinal peristalsis and obvious space-occupying lesions, but the sensitivity of segmental lesions and small space-occupying lesions is not high, and is unable to observe the pathological changes parenteral infiltration or parenteral lesions in small intestine infiltration. Small bowel enema pneumobarium double contrast radiography shows the overlapping intestinal clearly, is advantageous to show microscopic lesions, but the SBE should be intubated, patients would be pain, display gut lesions and vascular lesions unclearly, and for fistula too. Electron enteroscopy examination can diagnose and biopsy and treat small intestinal lesions, but it is expensive, and enteroscopy operating require high technology, inspection consumed time. Double sac electronic enteroscopy’s price is expensive, and it easy to stay in the narrow place, lumen and it only observe the cavity, so its application in the small bowel lesions also be restricted. Capsule endoscopy plays an important role in gastrointestinal bleeding of unknown origin and the diagnosis of Crohn’s disease, but there are many taboos and dangerous complications-lodged. Due to the gas interference inside the lumen, ultrasonic inspection usually display not ideal, can’t clearly distinguish, so its application in small bowel lesions is less. MR small bowel imaging is a inspection method of combined with the advantages of traditional small bowel imaging and magnetic resonance (NMR) morphological imaging. But MR small bowel imaging examination has more taboo, and MR examination time is relatively long.The emergence of multislice CT and widely used in recent years, it expanded the check scope of small intestinal lesions. MSCT small bowel imaging is a inspection method of combined the advantages of routine abdominal multislice computed tomography (CT) and the small intestine angiography. The technology filled small intestinal lumen with contrast medium by mouth, and strengthened by the MSCT scan, and displayed viscera multi-dimensional the colon wall and lumen, parenteral mesangial, intra-abdominal vascular, retroperitoneum, and abdominal parenchymal by the image post-processing.Therefore, this study intends to evaluate small bowel expansion by oral mannite and discuss the application value of MSCTE in the small intestine lesions with enhancement scan.Chapter one:The optimization of MSCTE contrast agentsObjectiveTo discuss appropriate MSCTE oral contrast agent and optimize by comparing to the methods of small intestine expansion, fully filling insufflate.Materials and methods1. Clinical dataCollected30normal volunteers without small intestinal lesions which inspected by multislice spiral CT in our hospital, the male16, female14cases, aged17～69years old. Normal volunteers inclusion criteria:1. no diseases such as glaucoma, hypertrophy of the prostate and urinary retention;2. no systemic disease;3. no serious heart, liver, renal insufficiency, there is no history of allergies. Volunteers are randomly divided into3groups, take three different medium contrast to fill small intestine orally. The first group of10cases take isotonic mannitol as oral contrast agent; A second group of10cases take pure milk (3%fat) as oral contrast agent; The third group of10cases take water as oral contrast agent.2. CT examination method2.1Equipment and pharmaceutical preparation before inspection2.1.1Equipment:The Siemens dual-source CT scanners; The new communication station; CT binoculars high-pressure syringe; PASC;2.1.2Main drugs:Anisodamine injection,20%mannitol injection, CT contrast agent (sea iodine, alcohol,100ml,300mgi/ml).2.2Intestinal preparation before checkFirst booking inspection time, notify all normal volunteers check method, consent of myself and family members, sign CT enhancement scanning informed consent. Three days before the check not to do anything positive gastrointestinal contrast agent (barium, iodine). Check before two days have low fat, low fibre diet, Check before night take into semi-liquid diet without slag, clean intestine by using magnesium sulfate or senna, and drink water more than1500ml.Part of patients with constipation can be extended emptying time appropriately, until no waste, prohibited water and food before check.2.3The methods of filling small intestineThree groups of volunteers drink1500ml corresponding contrast agent in60minutes before the scheduled inspection4times, the interval of time is10minutes. Patients are told each recumbent on mobile carts after take oral contrast agent. Taked muscular injection of20mg654-2in5～10minutes before the examination. Take about300ml oral contrast agents before scanning again, and ready to CT examination. Ask patients what discomfort and pain tolerance for this inspection, presence of complications were observed after the check.2.4CT examination technology2.4.1Scanning scope:whole abdomen, since the diaphragmatic top to the edge of pubic symphysis;2.4.2Scanning parameters:the tube current:open automatic modulation current and reference mAs is300mAs, effective mAs is125～245mAs, flat sweep phases during250-270mAs, enhance phases during340～380mAs; Machine speed0.38s/r, collimating0.38mm, pitch of0.8; Layer thickness and spacing are7mm, effective thickness of1.5mm, reconstruction interval is1.0mm, the average scan time is6-7s.2.4.3Scanning methods A breathless from top to bottom to complete full abdominal scan, scan also adopts a breathless from top to bottom, using iodine sea alcohol injection (concentration of300mgi/ml) as a contrast agent, the dosage of about80-100ml, CT binocular high-pressure syringe, the elbow superficial vein injection, the injection velocity of about3～3.5ml/s; After injection of physiological saline at the same rate of30ml, arterial scanning using artificial intelligence to trigger software, monitoring stations in abdominal aorta, trigger threshold is set to110hu, when to trigger threshold, automatically start scanning program, complete the scan, arterial interval after about30～40s start scanning program, complete portal phase scanning.2.5Image post-processing Move each raw data retrospective reconstruction, thickness1.5mm, layer spacing of1.0mm, then transmit the data to the workstation for data analysis after reconstruction.3d reconstruction method mainly has many surface reconstruction and curved surface reconstruction, maximum density projection and volume imaging and CT angiography.3. The image analysisPrinciple by two experienced by blind method of doctor of vice director of the above abdomen to image analysis, image diagnosis expert diagnosis disagree agree through consultation, evaluation index including:Intestinal preparation; The patient’s tolerance level;Intestinal canal filling condition evaluation Small intestine score filling degree,90% or more of the small intestine to see filled with contrast medium, review4points;70a89% rating3points;40a69% rating2points; Less than40% for1minute. At the same time according to the distribution degree of overlap and the length of the small intestine can be divided into:the uniform type, compact type and discrete.Observe the duodenum, jejunum and ileum paragraphs insufflate the width, the thickness of the tube wall, the wall CT value of arterial phase, portal phase and contrast-enhanced CT value in the lumen.4. The statistical analysisData statistical analysis by SPSS17.0software package. Small bowel wall cavity expansion ratio, small intestine paragraphs CT value and luminal CT value to mean±standard deviation; Comparison between multiple sets of data set, meet the homogeneity of variance with Oneway ANOVA, P<0.05using LSD to do two more; Variance is used when Welch, P<0.05using Dunnett T3do two two compared. Comparison portal phase of oral contrast agents in the lumen and intestinal wall CT values to found no statistical difference, P<0.05, with statistical significance.ResultsAll volunteers are agreed to and complete the MSCTE and small bowel CT enhancement, no obvious discomfort, no contrast agent allergic reaction. Between groups of intestinal cleanliness higher, less residue of intestinal contents.1. No statistical difference between the three groups of age and gender.2.In the patient’s tolerance, no significant differences between the filling method (P>0.05).3.The distribution of the small intestine:uniform type (n=12), density (3) the case of discrete (n=15).4.Small bowel expansion degree of two two compared between three groups has statistics difference (P<0.05), mannitol group expansion degree good, pure milk group expansion center, plain water expansion ratio is a bit poor.5.Three groups all showed ileal expansion degree is best, jejunum second, duodenal expansion effect is a bit poor.6.The duodenum, the jejunum tube wall CT values compared with ileal wall CT value was statistically difference (P<0.05), no statistical difference between the duodenum and jejunum tube wall CT value (P>0.05).7.The arterial phase, portal phase between the three way wall compared with CT value.Conclusion1. Isotonic mannitol is a good oral contrast medium of small intestine.2. Intravenous contrast agent (sea iodine, alcohol) can make the intestinal wall reinforcement, increase the density difference between the tube cavity and the tube wall. It is advantageous to show the intestinal lesions.Chapter two Normal intestine MSCT small bowel imaging manifestations and normal researchObjectiveFor oral isotonic mannitol prepared small intestine after MSCT scan, summarizes its normal performance.Materials and methods1. Clinical dataCollect in our line of MSCT small bowel imaging examination of small intestinal lesions in30normal volunteers, the male17, female13cases, aged17-68years old. Normal volunteers inclusion criteria:1, no diseases such as glaucoma, hypertrophy of the prostate and urinary retention;2, no systemic disease;3, no serious heart, liver, renal insufficiency, and there is no history of allergies. All volunteers are filled with isotonic mannitol intestinal, the method of scanning5～10minutes before the20mg muscle injection of654-2.2. CT examination method2.1Equipment and pharmaceutical preparation before inspection:The same as first chapter. 2.2Intestinal preparation before check:The same as first chapter.2.3The methods of small intestinal filling:The same as first chapter Mannitol group filling method.2.4CT examination technology:The same as first chapter.3. The image analysis3.1Groups of intestine:duodenum, jejunum and ileum.3.2Observation index:Intestinal wall thickness, stratification of the intestinal wall, intestinal wall scan and enhanced CT value, jejunum mucosal fold number and mesenteric vessels, mesenteric fat density. The above indicators were diagnosed by two of the digestive tract has rich experience of doctor of vice director of the above radiologists blinded reading image data, the consistent conclusion.4. The statistical methodsMainly used SPSS17.0software, the mean±tandard deviation to the determination results, the stratification of pipe wall thickness, wall, wall reinforcement and mesenteric fat density, jejunum mucosal fold number and mesenteric vessels such as measurement data to carry on the analysis of variance between groups. Mesenteric lymph nodes and peritoneum lymph nodes after counting data rate compared by chi-square test, P<0.05, statistically significant.Results1. The normal small intestinal wall thickness between1.34～2.54mm, with a mean of2.06mm, the standard deviation of0.26mm; On intestinal wall thickness in the small groups analysis of variance, there was no statistically significant difference (F=0.069, P=0.069).2. Normal intestine filling insufflate width is14.10～33.46mm,23.22mm on average, standard deviation of4.86mm; With good segment of small intestine group, its association with width all around23mm; Difference was statistically significant between each paragraph (F=8.810, P=8.810).3. Normal intestinal wall scan CT value is (27.75±3.80)HU, the difference was statistically significant between each paragraph (F=7.376, P=7.376). Small intestine wall arterial wall strengthening overall average (65.82±8.28) HU, duodenum, jejunum of arterial enhancement CT average should be higher than the ileum; Difference was statistically significant between each paragraph (F=37.667, P=37.667). Small intestine wall portal phase of the intestinal wall strengthening overall average (81.28±10.92) HU, duodenum, jejunum portal phase enhancement CT average higher than the ileum; Difference was statistically significant between each paragraph (F=5.650, P=5.650).4. The normal intestinal wall layered rare, only the duodenum is3.75%in this group of data appear statified phenomenon, the walls of her intestines the rest of the paragraphs are single intestinal wall.5. Normal jejunum mucosal fold number was2.40±2.40; Normal mesenteric vessels was2.70±0.64.6. Minimum normal mesenteric fat density-114.71HU, a maximum of-63.44HU, an average of-79.17HU, standard deviations is12.87HU.ConclusionsNormal bowel CT performance and the measure can lay a foundation for diagnosis and differential diagnosis of small intestinal lesions, and can be used as a reference index of evaluation of the small intestine.Chapter three The applications of oral mannite MSCTE in small bowel lesionsObjectiveThrough oral isotonic mannitol with multislice CT to improve the detection of small bowel lesions, to investigate the value of MSCTE check in small bowel lesions and superiority.Materials and methods 1. Clinical dataCollected in our hospital cases suspected small intestinal barium meal, CT examination, and clinical examination and pathological changes of MSCT patients with small bowel imaging examination, a total of43cases,27cases of men, women,38cases, aged15-68years, mean age45.31±12.41years, the duration is7-16years. Major clinical manifestations for different level accompanied by abdominal pain, abdominal distention, diarrhea, nausea, vomiting, fever, anaemic, angular, abdominal mass, loss of weight and defecate occult blood and other symptoms.2. CT examination method2.1Equipment and pharmaceutical preparation before inspection:The same as first chapter.2.2Intestinal preparation before check:The same as first chapter.2.3The methods of small intestinal filling:The same as first chapter.2.4CT examination technology:The same as second chapter.3. Image analysis indicatorsFor multiple planar reconstruction (MPR), curved surface reconstruction (CPR), maximum density projection (MIP), volume imaging techniques (VRT), CT angiography (CTA) of pathological changes of image carries on the comprehensive analysis of small intestine mucosa thickening of intestinal wall and the intestinal lumen stenosis, small intestinal obstruction, intestinal nested, stratification of the intestinal wall longitudinal, cross the lesion signs, pathological changes, the density of lesions the average CT value, mesenteric fat, mesenteric vessels, mesenteric lymph nodes and peritoneum lymph nodes, after a long softness.Above post-processing workstation measurement analysis indicators, quantitative data:the transverse diameter measurement in shaft or MPR reconstruction images, longitudinal diameter measuring MPR reconstruction image. Quantitative data by two radiologists physician to complete all the measurements. By two in the digestive tract.4. The statistical methodsStatistical analysis using SPSS17.0statistical package. Measurement data analysis mainly USES the t test, analysis of count data is mainly using chi-square test, P<0.05, statistically significant.Results1. The general situationMost of patients are willing to accept MSCTE checked, and successfully completed, at the end of three of the patients with suspected small intestinal obstruction can be oral isotonic mannitol, other are feeling after taking taste slightly sweet, with no other discomfort. Intestinal well-prepared, filling degree of basic satisfaction, pathological changes around the intestine good filling and conform to the requirements of the diagnosis.43cases of suspected small bowel lesions in patients with small intestinal tumor lesions, a total of15cases, interstitial tumor in5cases, lymphoma and6cases of duodenal adenocarcinoma in2cases, omentum transfer in2cases, small intestine. Small intestinal inflammatory lesions, a total of20cases,8cases of Crohn’s disease (CD),5cases of intestinal tuberculosis, acidophil gastroenteritis (3cases), intestinal fiber adhesion with vascular hyperplasia in1case, Meckel diverticulum and bleeding in1case, empty the ileum chronic ulcer with inflammatory polyp in2cases, the others are,1case of intestinal lymphangiectasia, small intestine amyloidosis associated with incomplete intestinal obstruction in2cases, gastrointestinal dysfunction in1case,3cases of small intestinal mechanical obstruction, normal in1case. Case samples for the few and scattered, not signs of further analysis.37cases of surgery, endoscopic or biopsy pathology confirmed, the other6cases for clinical comprehensive diagnosis.2. MSCTE imaging findings of small bowel tumor lesions2.1Small intestine tumor lesions involving the most is the duodenum, accounted for50%of all cases, the minimum involvement of jejunum, accounted for19%, accounted for28%of the ileum, whole small intestine and intestinal colon segment joint under3%.2.2Small intestinal tumor lesions on CT signs show up for the small bowel wall thickening (80.00%), at least for small intestine nested (13.33%).2.3Small intestine tumor lesions of CT measurementsSmall intestinal tumor pathological lesions scan period the average CT value of43.83±6.61Hu, enhance arterial average CT value of66.80±10.43Hu, enhance portal period the average CT value of72.53±8.85Hu.Small intestinal tumor pathological lesions enhanced CT arterial than scan CT value increased an average of35.15±3.99mm; Enhance portal phase CT value than scan CT value increased an average of46.65±6.71mm; Enhance portal with enhanced CT arterial phase CT value value increased an average of11.98±2.30. By the single factor analysis of variance between groups F=9.567, P=0.000, tip small intestinal tumors in the scan period, enhance agent arterial enhancement portal period between CT value exists obvious difference, CT value increase.Small intestinal tumor pathological lesions on CT and longitudinal diameter with a mean of65.89±29.01mm, the transverse diameter of44.47±16.70mm.Small intestinal tumor pathological changes of mesenteric fat density of83.40±21.51Hu,mesenteric vessels2.46±0.79n/cm.3. Small intestinal inflammation lesions MSCTE performance3.1Small intestinal inflammatory lesions involving the ileum and ileocecus is more,37%and33%respectively, the minimum for total small bowel involvement, accounted for11.54%.3.2Trail inflammatory lesions CT signs appear most for small bowel wall thickening and intestinal wall layer (55.00%). The rest of the signs are less than50.00%.3.3Intestinal inflammatory diseases CT measurements of the ovenIntestinal inflammation lesions lesions scan period the average CT value of35.66±7.64Hu, enhance arterial average CT value of63.73±13.15Hu, enhance portal period the average CT value of100.13±21.11Hu.Intestinal inflammation lesions lesion enhancement CT arterial than scan CT values increased an average of43.45±11.35mm; Enhance portal phase CT value than scan CT value increased an average of59.13±15.60mm; Enhance portal with enhanced CT arterial phase CT value value increased an average of39.23±6.57. By the single factor analysis of variance between groups F=8.67, P=0.001, tip intestinal inflammation in the scan period, enhance agent thickening of arterial, portal vein phase, between CT value obvious raise, CT value increase.Intestinal inflammation lesions lesions with a mean of117.85CT measurement of longitudinal diameter, transverse diameter of9.73.Intestinal inflammation lesions mesenteric fat density up to29.65Hu, the lowest for-110.45Hu, on average.80.16Hu.ConclusionsOral mannite CT scanning is helpful to display small intestinal structure and morphology, to locate and qualitative small intestine lesion. It has a certain reference value of diagnosis and differential diagnosis of small intestinal lesions, and can be as one of the small intestine disease check option. |
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