• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.39-48
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• 2000

Background: There arc two theories in the development of colon cancer. One is the adenoma-carcinoma sequence theory and the other is the de novo cancer theory. Western countries believe in the adenoma-carcinoma sequence theory, however there are many recent reports from, Japan about cancers developing from small adenomas. Methods: The present study analyzed 408 polyps from 508 cases that were taken by colonoscopic polypectomy at the Department of internal Medicine, Yeungnam University Hospital. Results: The percentage of patients who had a polyp was 41.3% (210 cases out of 526 cases), and the peak incidence was noted in patients in their 50s and 60s, There was no difference between the sexes, but we noted significant increase in the incidence of polyps in patients over the age of thirty. We found 395 polyps below 1cm and 13 polyps above 1cm. Among 408 polyps, 5 cases were cancerous polyps and 3 cases showed polyp size of less than 1cm each. The first case was a polyp of 0.4cm in size with elevated mucosa at the ascending colon. The second was 0.5cm in size with round elevation and hyperemic mucosa in the rectum. The third was 0.6cm in size with tubular elevation at the hepatic flexure. Conclusions: Colon polyp is a common disease in Koreans, Even small polyps can have cancer tissue, which should be removed if discovered during colonoscopy. We believe that not all colon cancer originates in the manner described by the adenoma-carcinoma sequence theory. However further studies with a larger sample population arc needed to determine the exact role of colon polyps in the development of colon cancer.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.69-75
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• 2003

Virtual colonoscopy is one of the Powerful tool for non-invasive colon examination and many in-vitro and in-vivo studies have shown its accuracy in Polyp or adenoma detection. But most of virtual colonoscopy requires high quality workstation and software and its cost is high to setup whole system. We developed PC-based 3D model creation and navigation program which has diverse functions. It can be easily installed to PC and connected to network system. The performance. when used as a virtual colonoscopy. is evaluated by calculating sensitivity of detection for the simulated polyp which is artificially made inside the Pig's colon and checked its clinical feasibility, Its total sensitivity is 76%. Grouping according to Polyps diameter, the sensitivity for detection of polyps 10 ㎜ or larger was 100%(40 of 40); 5.0-9.9 ㎜, 90.0(90 of 100): and smaller then 5 ㎜. 36.7%(22 of 60).

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5163-5167
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• 2015

Background: Colon polyps need to be excised upon detection during colonoscopy due to the risk of malignancy irrespective of their size. In our study, we retrospectively evaluated the clinicopathological characteristics of polyps detected during colonoscopy. Materials and Methods: We assessed 379 patients with polyps detected during colonoscopy between January 2010 and May 2012. The demographics, complaints, colonoscopy findings (shape, place and size of the polyp) and histopathological findings were recorded. We carried out statistical analysis using PASW 18.0 for Windows. Results: There were 227 males (59.9%) and 152 females (40.1%) in the trial. The mean age was 53.8 years (32-90). The most common complaint was rectal bleeding (36.1%), followed by abdominal pain (35.4%). Polyps were detected most commonly in the rectosigmoid region (43.8%), followed by the descending colon (17.4%). Some 239 patients had a single polyp (63.1%) while 140 were found to have multiple polyps (36.9%). While tubular adenoma was the most common pathological type, occurring in 181 patients (47.8%), tubulovillous adenoma (14.2%) and hyperplastic polyp (12.7%) followed, occurring in 54 and 48 patients respectively. While 313 patients (82.6%) did not feature dysplasia, 37 patients (9.7%) exhibited low-grade dysplasia, 28 (7.7%) had high-grade dysplasia and 4 had cancer (1.1%). The rates of villous components and dysplasia were detected to be high among pedunculated polyps and polyps larger than 1 cm (p<0.001). Conclusions: Due to the fact that large-diameter polyps with malignant potential are commonly located in the left colon and have a high prevalence among the middle-aged individuals, it would be appropriate to screen this population at regular intervals via rectosigmoidoscopy.

• Journal of Yeungnam Medical Science
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• v.22 no.1
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• pp.113-118
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• 2005

Diverticulosis of the small intestine is a rare entity, compared with that of duodenum or colon, and is found in only 1% of autopsied patients. The main complications are diverticulitis with or without a perforation, obstruction and hemorrhage, which are associated with a high mortality. Intussusception is primarily a disease of childhood; with only 5 to 10% of cases occurring in adults. In contrast to childhood intussusception, 90% of adult intussusception cases are had an associated pathologic processes. An inflammatory fibroid polyp is an uncommonly localized non-neoplastic lesion of the gastrointestinal tract. It occurs most often in the stomach and secondly in the ileum. It rarely occurs in other organs such as the colon, jejunum, duodenum and esophagus. We report a case of jejunal diverticulitis with a perforation combined with intussusception caused by an inflammatory fibroid polyp. A 78-year-old female presented with abdominal pain, fever and chill. Contrast CT scan showed intussusception of the ileum. The patient was treated with a small bowel segmental resection. After surgery, the specimen showed jejunal diverticulitis with perforation.

• Journal of KIISE:Software and Applications
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• v.35 no.8
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• pp.493-500
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• 2008

This paper proposes an electronic colon cleansing method using a patient CT profile for a virtual colonoscopy. The proposed method extracts the colon using cubic seeded region growing, and removes tagged materials adjacent to the colon. Residuals produced by a partial volume effect at the boundary of air-tagged material are deleted, and the removed soft tissue pixels due to a partial volume effect at the boundary of tagged material-soft tissue are recovered using a patient CT profile. The proposed method was applied to 16 virtual colonoscopy patient data sets, and produced promising results by a subjective evaluation of a radiologist and by a quantitative evaluation of a computer-aided diagnosis system.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1361-1364
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• 2012

Background: Results of screening colonoscopy from Western countries reported adenoma detection rates (ADRs) of 30-40% while those from Asia had ADR as low as 10%. There have been limited data regarding screening colonoscopy in Thailand. The objectives of this study were therefore to determine polyp and adenoma detection rates in Thai people, to evaluate the incidence of colorectal cancer detected during screening colonoscopy and to determine the endoscopic findings of the polyps which might have some impact on endoscopists to perform polypectomy. Materials & Methods: This study was a retrospective electronic chart review of asymptomatic Thai adults who underwent screening colonoscopy in our endoscopic center from June 2007 to October 2010.Results: A total of 1,594 cases were reviewed. The patients had an average age of $58.3{\pm}10.5$ years (range 27-82) and 55.5% were female. Most of the cases (83.8%) were handled by staff who were endoscopists. A total of 488 patients (30.6%) were reported to have colonic polyps. Left-sided colon was the most common site (45.1%), followed by right-sided colon (36.5%) and the rectum (18%). Those polyps were removed in 97.5% of cases and 88.5 % of the polyps were sent for histopathology (data lost 11.5%). Two hundred and sixty three cases had adenomatous polyps, accounting for 16.5 % ADR. Advanced adenomas were detected in 43 cases (2.6%). Hyperplastic polyps were mainly located distal to the splenic flexure of the colon whereas adenomas were found throughout the large intestine. Ten cases (0.6%) were found to have colorectal cancer. Four advanced adenomas and two malignant polyps were reported in lesions ${\leq}$ 5 mm. Conclusion: The polyp detection rate, adenoma detection rate, advanced adenoma detection rate and colorectal cancer detection rate in the screening colonoscopy of Thai adults were 30.9%, 16.5%, 2.6% and 0.6% respectively. Malignant transformation was detected regardless of the size and location of the polyps. Therefore, new technology would play an important role indistinguishing polyps.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5111-5116
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• 2014

Computed Tomography Colonography (CTC) is a medical imaging technology used in identifying polyps and colon cancer masses in the large intestine. The technique has evolved a great deal since its invention and has become a routine diagnostic procedure in Western countries due to its non invasiveness and ease of use. The objective of our study was to explore the possibility of CTC application in Indian hospitals. This paper gives an overview of the procedure and its commercial viability. The explanation begins with the domain aspects from gastroenterologist perspective, the new way of thinking in polyp classification, the technical components of CTC procedure, and how engineering solutions have helped clinicians in solving the complexities involved in colon diagnosis. The colon cancer statistics in India and the results of single institution study we carried out with retrospective data is explained. By considering the increasing number of patients developing colon malignancies, the practicality of CTC in Indian hospitals is discussed. This paper does not reveal any technical aspects (algorithms) of engineering solutions implemented in CTC.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8351-8358
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• 2016

Electronic cleansing is an image post processing technique in which the tagged colonic content is subtracted from colon using CTC images. There are post processing artefacts, like: 1) soft tissue degradation; 2) incomplete cleansing; 3) misclassification of polyp due to pseudo enhanced voxels; and 4) pseudo soft tissue structures. The objective of the study was to subtract the tagged colonic content without losing the soft tissue structures. This paper proposes a novel adaptive method to solve the first three problems using a multi-step algorithm. It uses a new edge model-based method which involves colon segmentation, priori information of Hounsfield units (HU) of different colonic contents at specific tube voltages, subtracting the tagging materials, restoring the soft tissue structures based on selective HU, removing boundary between air-contrast, and applying a filter to clean minute particles due to improperly tagged endoluminal fluids which appear as noise. The main finding of the study was submerged soft tissue structures were absolutely preserved and the pseudo enhanced intensities were corrected without any artifact. The method was implemented with multithreading for parallel processing in a high performance computer. The technique was applied on a fecal tagged dataset (30 patients) where the tagging agent was not completely removed from colon. The results were then qualitatively validated by radiologists for any image processing artifacts.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4143-4147
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• 2016

Purpose: We evaluated all PET/CTs acquired for patients without a primary diagnosis of colorectal cancer, and compared results for those who had subsequent colonoscopy within 6 months, to assess the accuracy of FDG PET/CT for detection of incidental pre-malignant polyps and malignant colon cancers. Materials and Methods: Medical records of 9,545 patients who underwent F-18 FDG PET/CT studies over 3.5 years were retrospectively reviewed. Due to pre-existing diagnosis of colorectal cancer, 818 patients were excluded. Of the remainder, 157 patients had colonoscopy within 6 months (79 males; mean age 61). We divided the colon into 4 regions and compared PET/CT results for each region with colonoscopy and histopathologic findings. True positive lesions included colorectal cancer, villous adenoma, tubulovillous adenoma, tubular adenoma and serrated hyperplastic polyp/hyperplastic polyposis. Results: Of 157 patients, 44 had incidental colonic uptake on PET/CT (28%). Of those, 25 had true positive (TP) uptake, yielding a 48% positive predictive value (PPV); 9% (4/44) were adenocarcinoma. There were 23 false positive (FP) lesions of which 4 were hyperplastic polyp, one was juvenile polyp and 7 were explained by diverticulitis. Fifty eight patients had false negative PET scans but colonoscopy revealed true pre-malignant and malignant pathology, yielding 23% sensitivity. The specificity, negiative predictive value (NPV) and accuracy were 96%, 90% and 87%, respectively. The average SUVmax values of TP, FP and FN lesions were 7.25, 6.11 and 2.76, respectively. There were no significant difference between SUVmax of TP lesions and FP lesions (p>0.95) but significantly higher than in FN lesions (p<0.001). The average size (by histopathology and colonoscopy) of TP lesions was 18.1 mm, statistically different from that of FN lesions which was 5.9 mm (p<0.001). Fifty-one percent of FN lesions were smaller than 5 mm (29/57) and 88% smaller than 10 mm (50/57). Conclusions: The high positive predictive value of incidental focal colonic FDG uptake of 48% for colonic neoplasia suggests that colonoscopy follow-up is warranted with this finding. We observed a low sensitivity of standardly acquired FDG-PET/CT for detecting small polyps, especially those less than 5 mm. Clinician and radiologists should be aware of the high PPV of focal colonic uptake reflecting pre-malignant and malignant lesions, and the need for appropriate follow up.

• Journal of Digestive Cancer Research
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• v.12 no.2
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• pp.90-101
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• 2024

The incidence of colon cancer in South Korea has recently been the highest among gastrointestinal cancers. Early diagnosis is critical, and image-enhanced endoscopy (IEE) is a key diagnostic method. Colon tumors primarily include serrated polyps, adenomatous polyps, and colon cancer. Early endoscopic techniques relied on simple visual inspection for diagnosis, with tumor size and shape being the primary considerations. Low-resolution images made these methods ineffective for detecting small or early-stage lesions. IEE now enables detailed examination using high-resolution images and various color and structure analyses. Techniques like narrow band imaging (NBI) allow precise observation of vascular patterns and surface structures. Hyperplastic polyps often appear similar in color to the surrounding mucosa, with no visible vascular pattern. Sessile serrated lesions have a cloudy surface with distinct boundaries and irregular patterns, often with black spots in the crypts. Adenomatous polyps are darker brown, with a visible white epithelial network and various pit patterns. Magnified images help differentiate between low- and high-grade dysplasia, with low-grade showing regular patterns and high-grade showing increased irregularities. The NBI International Colorectal Endoscopic classification identifies malignant colon tumors as brown or dark brown with disorganized vascular patterns. The Japan NBI Expert Team classification includes loose vascular areas and disrupted thick vessels. The Workgroup serrAted polypS and Polyposis classification aids in differentiating between hyperplastic polyps and sessile serrated lesions/adenomas when deciding whether to resect polyps larger than 5 mm. Suspected high-grade dysplasia warrants endoscopic submucosal dissection and follow-up. Future advancements in IEE are expected to further enhance early detection and diagnostic accuracy.