| Chapter oneExperimental Evaluation of detection for space-occupying in porcine jejunum model with 64-slice CT scannerBackgroud and ObjectiveSmall intestinal tumours, being non-specific in clinical symptoms and lack of ideal examination methods for anatomical reasons, are difficult to diagnose, especially tumours of jejunum and ileum, with a low preoperative diagnosis rate. New methods of examining the small intestinal tumour have been explored in recent years. In this paper, through the experiment of detection for space-occupying in porcine jejunum model with 64-slice CT scanner, to assess the impact of detection for mimic space-occupying in porcine jejunum in different filling conditions (complete filling, half filling, quarter filling and no filling) and filling methods (gas or water) with 64-slice CT scanner. MethodsMade space-occuping model with fresh porcine jejunum:We have made 32 segments of fresh porcine jejunum with 30 cm in length and implanted space-occupying lesions on the mucous surface in each segment. There were six lesions in each segment with a pair of lesions with a diameter of 5 mm,10 mm and 15 mm respectively. Then all the segments were divided into 2 groups: gas-filling group(group A) and water-filling group(group B) with 16 segments separately. The samples for each group were scanned with 64-slice CT under different filling conditions:complete filling, half filling, quarter filling and no filling. The datas then were transported to workstation and analyzed with post-processing techniques. We have used 0-3 point score system to evaluate the detection of lesions in different filling samples:nothing detected for score 0, suspectable lesion for score 1, the lesion was showed with blurry border for score 2 and with clear border for score 3. The features of space-occupying lesions were observed and compared between two groups and different filling conditions.Results1 The quality of CT images of 32 segments of jejunum were excellent and with no artifacts in the observational areas.2 The comparison between different filling conditions:Different filling conditions did have impact on the detection of occuping lesions(group A:x2=287.730, P＜0.001;group B:X2=66.375, P＜0.001). The better intestine filled, the better lesions were displayed.3 The comparison between groups A and B:For the lesions with diameter of 5 mm, statistical difference were showed between A and B in complete filling (X2=56.392, P<0.05), half filling (X2=51.404, P＜0.05) and quarter filling (X2=26.359, P<0.05). As well as for the lesions of 10 mm, there were significant differences in complete filling (X2=19.286, P<0.05); half filling (X2=57.600, P<0.05) and quarter filling (X2=11.403, P＜0.05). For the lesions of 15mm, there were no differences between A and B in the complete filling and both groups displayed the lesions clearly; However, significant differences were showed between A and B in half filling(X2=28.638, P<0.05) and quarter filling(X2=12.106, P＜0.05). Gas-filling group was superior to water-filling group.Conclusions1. Adequate filling with gas or water at CT scanning is very important for the display of small intestinal neoplasms. The better intestine filled, the better lesions are displayed.2. Gas-filling is superior to water-filling for the display of lesions with diameter 5 mm and 10 mm. The navigation software of filling wih gas can show mucosal surface of small bowel and improve the detection rate of smaller lesions.Chapter twoThe Diagnostic Accuracy of Enhanced Multi-slice Spiral CT Virtual Endoscopy for Small Intestinal TumoursBackgroud and ObjectiveThrough the model experiment in the chapter one, we had concluded that gas-filling is superior to water-filling, the better intestine filled, the better lesions are displayed. In this chapter, our purpose is that through the analysis of clinical cases performed multi-slice spiral CT examination in the condition of sufficient gas-filling, to further study the diagnostic accuracy of enhanced multi-slice spiral CT virtual endoscopy (MSCT-VE) for small intestinal tumours, to analyze the CT characteristic for diagnosis and differential diagnosis of intestinal tumors.Materials and Methods There were 133 cases with complete clinical data, undertaken small intestinal CTVE examination from 2001 to 2011 in our hospital were reviewed. Clinical symptoms:long-time unexplained chronic abdominal pain, diarrhoea, constipation, fatigue, weight loss or intermittent gastrointestinal bleeding. All patients were excluded by gastroscopy and colonoscopy for stomogastric and colonic causes before examination and were given standard gastrointestinal tracts cleansing and took aerogenic agent orally to make sure gas filling into the duodenum and upper jejunum from the stomach. When patients were laying on the scanning table, addition gas was introduced into colon by a remotely controlled coloclysis equipment with slow speed to make sure that the gas be imported to small bowel via ileocecal valve and made the small bowel filled up.54 cases were examined on 4-slice CT(GE Lightspeed Plus), 79 cases on 64-slice CT(GE Lightspeed VCT). Unenhanced CT was performed first, followed by a dual phase enhancement in the supine position with 30s and 80s delay after the intravenous injection of contrast medium; this was followed by CT with a 180s delay in the prone position. Occasionally, additional CT in a lateral decubitus position would be necessary if the small bowel was not well distended. A total of 90-100ml(the total of children were computed by weight,1.5ml/kg) non-ionic contrast media (350mgI/ml omnipaque) was injected intravenously at 3.5-5ml/s. Images were reviewed on post-processing workstations with virtual endoscopy software and other post-processing methods including multi-planner reconstruction (MPR), maximum intensity projection (MIP) and volume rendering (VR). The study objects in this paper were the patients of small intestinal tumor who had been confirmed by histopathology among all cases to further evaluate the diagnostic value and accuracy of the enhanced MSCT-VE for small intestinal tumours.Results133 patients were successfully examined by CTVE. There were 38 small intestine tumours and 95 nontumourous cases among all 133 patients examined. All 38 tumours were proved by pathology. Among 38 cases of small-bowel neoplasm, 35 were detected by MSCT including 9 gastrointestinal stromal tumours, 10 lymphomas, 9 adenocarcinomas, 3 hemangiomas, 2 Brunner gland adenoma,1 lipoma, 1 leiomyoma. Three lesions were missed by CTVE, including 2 low-grade stromal tumours which were examined by a 4-detector spiral CT, and 1 fibrous harmatoma scanned by a 64-slice spiral CT. Two cases were false positive. Using the clinical diagnosis as the gold standard, we obtained the overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy with CTVE in identifying patients with small-bowel tumour at 92.1%,97.9%,94.6%, 96.9%,96.2% respectively.Conclusion1. Small intestinal CTVE technique has high diagnostic accuracy for the detection of intestinal tumours. Contrast enhancement, multi-position scanning and adequate intestinal tract gas-filling can improve the detection rate for small intestinal tumours.2. The shape of tumor and the feature of enhancement are helpful for the diagnosis and differential diagnosis of tumors. |
