The Applied Research Of Imaging In The Diagnosis Of Normal And Disease Of The Ileocecal Region

Objectives:1. To investigate the appearance of normal ileocecal region, and research the diagnosis and differential diagnosis value of imageology examination in ileocecal region diseases.2. To investigate the diagnositic and differential diagnositic values of CE CT and DCE MRI in ileocecal region diseases.Methods:1. To study the anatomy of appendix in 31corpses, recorded by the digital photo, to observe the shape of the appendix,to measure the length,the diameter,the position,and the relationship between the ileoceal vavle and the appendix.2. The Philips 1.5T MRI(thickness 7mm) and TOSHIBA 16 rows spiral CT(thickness 1mm) images of normal appendix were obtained in 134 subjects and 108 subjects, respectively, with emphasis on its position, size, shape and intensity or density.3. The TOSHIBA 16 rows spiral CT(thickness 1mm) and Philips 1.5T MRI(thickness 7mm) images of normal ileoceal valve were obtained in 74 subjects and 100 subjects, respectively, with emphasis on its position,size, shape and intensity or density.4. A study of 20 subjects who underwent TOSHIBA 16 rows spiral CT plain scaning and three stage enhancement scaning for other diseases, emphasized on the manifestation of the change of the mean ,CT value,vessel of the cecum,terminal ileum,appendix.5. The imaging appearances of 25 cases of the malignant tumor and 44 cases of the inflammation of the ileocecal region confirmed by operation and pathology were analysised retrospectively, to summarize the valve of various kinds'examination.Results:1. The appendix were present in all 31 corpses, it was a short or a earthworm-like caecus, There were uniform diameter in 18 (18/31,58%)corpses, and the distal segment were hypertrophied in 13(13/31,42%)corpses. The root of the appendix located at the posterior wall of the caecum in 27(27/31,87.1%) corpses, at the top of the caecum in 4 (4/31,12.9%)corpses. The distance between the appendix and the top of caecum was 0.1～5.9cm, between the appendix and ileoceal valve was 0.7～3.5cm. The direction variation of appendix were ante-terminal ileum in 17(17/31,54.8%)corpses, poster- terminal ileum in 14(14/31,45.2%)corpses. The length and diameter of the appendix were 1.5～8.9cm, 4～7mm ,retrospectively.2. The visibility of a normal appendix on routine MR imaging was 76.9 % (103/134). Its distance from ileal valve was 2 cm, it,s diameter was 5 mm ,it,s length was 1～9cm,it,s wall thickness was 1～2mm. It appeared as a cord-like structure of mediumT1, T2 intensity without fluid collection in the lumen. The visibility of a normal appendix on CT imaging was 82.4 % (89/108). It,s distance from ileal valve was 2 cm, it,s diameter was 5 mm ,it,s length was 1～8cm,it,s wall thickness was 1～2mm. It appeared as a para-caecum ring-shaped structure of isodensity or a caecus conjointed to posterior paries of caecum.3. The ileocecal valve was visible 100% (74/74) in CT group. The density of the valve was similar to the bowel wall. It,s morphology was divided into 5 types, bill, target,lip ,round cyst,mixed type. 69 cases(69/74,93.2%)valve located on the medial wall of the cecum,5 cases (5/74,6.8%)located on the posterior wall. The average valve height was1.20～2.80cm, average anteroposterior diameter was 1.02～3.02cm,and average width was 1.00～2.64cm.The ileocecal valve were visible 88%(88/100),14%(14/100),10%(10/100)on coronal,sagital,traverse,respectively in MRI group. The density of the valve was similar to the bowel wall tissue in T1WI, T2WI. The morphology were similar to CT imaging. 93 case(s93/100,93%)valve located on the medial wall of the cecum,7 cases (7/100,7%)located on the posterior wall. The average valve height was1.09～3.22cm, average anteroposterior diameter was 0.74～2.67cm,and average width was 0.90～2.70cm.4. The average CT valve of the cecum, terminal ileum,appendix respectively are 39.3HU,39HU,34.6HU,43.5HU in plain scan, ileocecal region has distinct structure,clear boundary,negative surrounding fat interspace. The average CT valve of the cecum at arterial phase, venous phase, delay period respectively are 67.6HU, 70.5HU, 58.3HU. The average CT valve of terminal ileum at arterial phase, venous phase, delay period differentially are67.4HU,79.7HU,69HU,The average CT valve of the appendix at arterial phase, venous phase, delay period respectively are 60.7HU,69.8 HU,47.6HU. The average CT valve of the right arteria iliaca at arterial phase, venous phase, delay period respectively are 288.6HU, 130HU, 84.3HU. 5. In 25 cancers,there were 22 adenocarcinoma,1 lymphoma,1 tumor in situ,1 malignant interstitialoma.The location of lesions were in ileoceal junction, in right hemicolon, in terminal ileum, in caecue, by turn. The tumor pathology shape were anabrotic form in 9 cases, hut form in 2 cases, irregular form in 14 cases.On ultrasound examination, 2 cases intussusception on right lower quadrant, 1 case small quantity ascites, 13 cases solid mass on ileocecal region, 1 case sack-solid mass on ileocecal region,1 case post-peritoneum multi- lymphadenectasis, 4 cases small intestine obstruction could be seen,2 ceses no abnormality seen. On barium meal, 10 cases lobulated, lateralization, irregular filling defection, mucosa destruction, and irregular intestinal stenosis could be seen. 2 cases round, filling defect on terminal ileum and small intestine obstruction,1 case lump, soft tissue on mesangial region, 2 cases niche sign, 1 case intussusception, 1 case whole colonospasm could be seen. On CT, 14 cases obviously irregular wall thickening, lump on ileocecal region,1 case round lump, 1 case small intestine obstruction,1 case invaded consol appendix, 2 cases right ureter invaded,1 case right psoas muscles invaded,1 case metastatic macrosis lump on right ovaries, 1 case liver and lung metastasis meanwhile,1 case liver metastasis,2 cases invaded necrosis on head of pancreas,3 cases a great quantity ascites,1 case small quantity hydrops para-intestine,2 cases irregular lobulated lump on para-wall,12 cases multi-node,consol on mesentery, 6 case post-peritoneum multi-lymphoid node, 1 case widespread peritoneum metastasis.1 case well-differentiated adenocarcinoma on MRI, obviously irregular wall thickening ,lumina narrowed on caecum and ileocecal junction, inner margin nodosity, outer margin lobulated,long T1,long T2 singal, multi mesenteric lymphadenectasis,right pelvic cavity lymphadenectasis, bilateralis inguinal lymphadenectasis,head of pancreas swelling and abnormity singal, liver abnormity singal multi-nodus,above-mentioned pathological changes obviously uneven intensification after enhancement,accompanying microcyst.In 44 inflammations, there were 14 acute purulent inflammations, which including 12 cellularis phlegmasia, 1 empyema, 2 abscess. There were 26 common chronic inflammations, 1 accompany abscess. There were 4 chronic granulomatous inflammation,which including 2 crohn disease, 1 tuberculosis, 1 syphilis.The location of lesions were in appendix,in ileoceal junction,in caecue,in terminal ileum,in right hemicolon,in ileoceal valve by turn. On ultrasound examination, 4 cases limitations, segment,wall thickening in right lower quadrant,1 case a great quantity ascites,7 cases a small quantity ascites,5 cases peritoneum thickening,1 case solid lump, 1 case strong echo lump,3 cases sack lump,3 cases mixed lump, 4 cases multi-lymphadenectasis in right abdominal cavity,5 cases appendix thickening, swelling, echo abnormity,2 cases appendix mild wall thicking,3 cases intestinal canal conglutination could be seen,8 cases no abnormality seen.On barium meal,6 cases bowel underfilling and quick peristalsis,2 cases appendix paramorphia, 2 cases post-peritoneum-liked lump, among these 3 cases intestinal canal borderline irregular, 10 cases mucous membrane thickening, mucous membrane derangement, 3 cases air-fluid level,1 case niche sign could be seen.On CT scan, 3 cases a small quantity ascites,3 cases air-fluid level,2 cases wall thicking,4 cases surrounding exudation,7 cases sack-solid lump,1 case embedding right ureter, 1 case surrounding conglutination,1 case caecum empyema,3 cases abdominal cavity or pelvic cavity empyema, 1 case appendix stercorolith could be seen.Conclusion:1. Most of appendix has invariable morphous and fixed location, mild diversitary length and diameter, although has some extent direction variation, but the majority appendix could be present clearly by normative imageology examination.2. The diameter of the appendix partly or entirely exceeded 6 mm; its wall thickness exceeded 2 mm, and accompanied phlegmona or abscess, were reliable signs to diagnose the appendicitis in CT. MRI is a supplementary method for examining appendix.3. 16-slices spiral CT is a pratical method for acquision of high-quality imaging of the ileocecal valve, allowing differentiating if the ileoceal vavle be involved in diseases. MRI is no X ray, it could be a supplementary method for examining ileoceal vavle for pregnant women and children.4. The normal ileocecal region has distinct structure, clear boundary in both plain and enhancement CT scanning, from light to moderate enhancement slowly, these signs is helpful to diagnose and differentially diagnose for ileocecal region diseases.5. The imaging examination has important value in diagnosis of the malignant tumor and the inflammation of the ileoceal region, especially CT could definitely localize and make sure the extent of diseases,directly show the thickness wall and the narrow lumens, extraordinarily swell lymphade and invaded surrounding mesentery,blood vessel,ureter,and remoteness organ metastasis.