Diagnostic value of i-Scan high definition endoscopy for screening polypoid lesions in right hemicolon / 中华消化内镜杂志

Objective To explore the diagnostic value of the i-Scan for detection of polypoid lesions in right hemicolon during colonoscopy. Methods A total of 200 patients who underwent colonoscopy in Beijing Shijitan Hospital from January 2015 to December 2015 were enrolled. After completion of the first colonoscopy in right hemicolon, a second withdrawal was performed, using white light mode ( white light group, n=93) and i-Scan mode ( i-scan group, n=96) to detect polypoid lesions in the proximal colon. The detection rates of polyp and adenoma were compared between the two groups. Results During the twice withdrawal, compared with white light group, more polyps and adenomas were detected in i-Scan group (1. 469 VS 1. 011, P=0. 028; 0. 979 VS 0. 624,P=0. 039). The proportion of patients with more polyps and adenomas in the i-Scan group was significantly higher than that in the white light group [ 37. 5％( 36/96) VS 22. 6％ ( 21/93) , P=0. 025;24. 0％ ( 23/96) VS 11. 8％ ( 11/93) ,P=0. 030] . i-Scan mode detected more small polyps with diameter<5 mm [ 84. 0％ ( 42/50 ) VS 58. 3％ ( 14/24 ) , P=0. 016 ] . However, there were no differences between the two groups in the size, location, and morphology of the detected adenomas ( all P>0. 05) . The polyp detection rates of the i-Scan group and white light group were 61. 5％ (59/96) and 48. 4％ (45/93), respectively (P=0. 071), and the adenoma detection rates were 47. 9％ (46/96) and 35. 5％ (33/93), respectively (P=0. 083). Conclusion I-Scan mode can increase the detection rate of polyps and adenomas in right hemicolon, and improve detection of polypoid lesions and bsmall polyps in patients with multiple polyps and adenomas.

La cromoendoscopia virtual i-Scan y su aplicación en la detección y caracterización de los pólipos de colon / Virtual Chromoendoscopy with I-Scan and its Application for Detection and Characterization of Colon Polyps

La limitación de la colonoscopia con luz blanca respecto a la omisión de neoplasias avanzadas en un 6%, y de adenomas hasta un 25%, ha motivado el desarrollo de técnicas como la cromoendoscopia virtual, entre ellas el sistema i-Scan, para detectar un mayor número de pólipos, como estrategia de prevención del cáncer de colon. Con esta revisión se resume la aplicación actual de este método en la detección de adenomas y su caracterización. Se ha encontrado que este nuevo sistema es una alternativa posible en nuestro medio a las ya existentes y mejor conocidas, como el NBI y FICE.

The limitations of white light colonoscopy result in missing 6% of advanced neoplasias in 6% and up to 25% of adenomas. This has motivated the development of techniques such as virtual chromoendoscopy including the i-Scan system to detect larger numbers of polyps as a strategy for preventing colon cancer. This review summarizes the current application of this technique for detection and characterization of adenomas. The new system is a possible alternative in our environment to the better known NBI and FICE which are already being used here

Increased Detection of Colorectal Polyps in Screening Colonoscopy Using High Definition i-SCAN Compared with Standard White Light

BACKGROUND/AIMS: The aim of this study was to evaluate the efficacy of high definition (HD) i-SCAN for colorectal polyp detection in screening colonoscopy. METHODS: We retrospectively analyzed the records of 501 patients who had undergone screening colonoscopy performed by three endoscopists with either HD i-SCAN (n=149) or standard white light (n=352) from January 2, 2014 through June 30, 2014. Patient information and inter-endoscopist variation as well as polyp number, endoscopic findings, and pathologic characteristics were reviewed. RESULTS: The detection rates of colorectal and neoplastic polyps were significantly higher using HD i-SCAN than standard white light colonoscopy (52% vs. 38.1%, p=0.004 for colorectal polyps; and 37.2% vs. 27.9%, p=0.041 for neoplastic polyps). Analysis of endoscopic findings revealed no difference in detected polyp size between HD i-SCAN and standard white light colonoscopy (4.59+/-2.35 mm vs. 4.82+/-2.81 mm, p=0.739), but non-protruding polyps were more commonly detected by i-SCAN than by standard white light colonoscopy (24.6% vs. 13.5%, p=0.007). CONCLUSIONS: Colonoscopy using HD i-SCAN had a significantly higher detection rate of colorectal polyps, including neoplastic polyps, because of improved sensitivity for detecting non-protruding lesions.

The Past, Present, and Future of Image-Enhanced Endoscopy

Despite the remarkable progress recently made to enhance the resolution of white-light endoscopy, detection, and diagnosis of premalignant lesions, such as adenomas and subtle early-stage cancers, remains a great challenge. As for example, although chromoendoscopy, such as endoscopy using indigo carmine, is useful for the early diagnosis of subtle lesions, the technique presents various disadvantages ranging from the time required for spray application of the dye and suctioning of excess dye to the increased difficulty in identifying lesions in the presence of severe inflammation and obstruction of visual field due to the pooling of solution in depressed-type lesions. To overcome these diagnostic problems associated with chromoendoscopy, research has focused on the development of endoscopes based on new optical technologies. Several types of image-enhanced endoscopy methods have recently been presented. In particular, image-enhanced endoscopy has emerged as a new paradigm for the diagnosis of gastrointestinal disorders. Image-enhanced endoscopes provide high-contrast images of lesions by means of optical or electronic technologies, including the contrast enhancement of the mucosal surface and of blood vessels. Chromoendoscopy, narrow-band imaging, i-SCAN, and flexible spectral imaging color enhancement are representative examples of image-enhanced endoscopy discussed in this paper.

Advanced Imaging Technology Other than Narrow Band Imaging

To improve the detection rate of gastrointestinal tumors, image-enhanced endoscopy has been widely used during screening and surveillance endoscopy in Korea. In addition to narrow band imaging (NBI) with/without magnification, various types of electronic chromoendoscopies have been used, including autofluorescence imaging, I-scan, and flexible spectral imaging color enhancement. These technologies enable the accurate characterization of tumors because they enable visualization of microvascular and microsurface patterns. The present review focuses on understanding the principle and clinical applications of advanced imaging technologies other than NBI.

Digital chrome endoscopy and confocai laser endomicroscopy in diagnosis of Barrett esophagus / 中华消化内镜杂志

ObjectiveTo evaluate digital chrome endoscopy (I-Scan) and confocal laser endomicroscopy (CLE) for diagnosis of Barrett esophagus (BE).MethodsFrom July 2010 to July 2011,a total of 878 outpatients who had upper gastrointestinal symptoms underwent routine endoscopy and I-Scan examination,screened patients with suspected Barrett's epithelial were further referred to CLE and endoscopy.The detection rate and image features of BE between routine endoscopy and I-Scan,and the diagnosis of BE between pathology and CLE,were compared respectively.ResultsSuspected BE was diagnosed in 46 patients (5.2％) by routine endoscopy,and in52 (5.9％) by I-Scan,and there was no significant difference in detection rate between 2 methods (x2 =0.533,P ＞ 0.05 ).The detection rate of paliform blood vessels between SCJ and GEJ was higher using I-Scan (35/52,67.3％ ) than routine endoscope (21/46,45.7％,P ＜0.05).A total of 19 suspected BE underwent CLE and biopsy,and BE was diagnosed by CLE with a sensitivity of 93％ and a specificity of 100％.ConclusionI-Scan is capable of identifying paliform blood vessels between SCJ and GEJ,and can improve the detection rate of suspected BE.CLE is able to provide in-vivo histological diagnosis of BE with a high sensitivity and specificity.

Efficacy of I-scan Endoscopy in the Diagnosis of Gastroesophageal Reflux Disease with Minimal Change

BACKGROUND/AIMS: The aim of the study was to evaluate the efficacy of i-scans for the diagnosis of gastroesophageal reflux disease, especially where only minimal change is involved. METHODS: The esophageal mucosa was inspected using an i-scan following conventional white light endoscopy. The examination with iscan was performed under tone enhancement (TE) esophagus (e) mode. Patients with subtle distal esophageal mucosal changes without definite mucosal breaks, such as blurring of Z-line (B), mucosal coarseness (C), hyperemic or purplish discoloration (D), erythema (E), ectopic gastric mucosal islet (I) and mixed type were classified as minimal change. RESULTS: A total of 156 patients were included. Using i-scan endoscopy, the number of minimal change was found to further increase from 94 (conventional endoscopy; 19B, 9C, 29D, 13E, 5I, 19 mixed type) to 109 (i-scan; 15B, 8C, 29D, 16E, 5I, 36 mixed type). And 14 patients who had single type by conventional endoscopy were converted to mixed type after i-scan. Therefore, 29 of 156 patients were upgraded after i-scan, they were account for 19% (p<0.0001; 95% confidence interval, 0.13 to 0.25). CONCLUSIONS: The use of i-scan endoscopy significantly improves the identification of minimal change and helps to identify more precisely the type of minimal change.

Efficacy of I-scan Endoscopy in the Diagnosis of Gastroesophageal Reflux Disease with Minimal Change

BACKGROUND/AIMS: The aim of the study was to evaluate the efficacy of i-scans for the diagnosis of gastroesophageal reflux disease, especially where only minimal change is involved. METHODS: The esophageal mucosa was inspected using an i-scan following conventional white light endoscopy. The examination with iscan was performed under tone enhancement (TE) esophagus (e) mode. Patients with subtle distal esophageal mucosal changes without definite mucosal breaks, such as blurring of Z-line (B), mucosal coarseness (C), hyperemic or purplish discoloration (D), erythema (E), ectopic gastric mucosal islet (I) and mixed type were classified as minimal change. RESULTS: A total of 156 patients were included. Using i-scan endoscopy, the number of minimal change was found to further increase from 94 (conventional endoscopy; 19B, 9C, 29D, 13E, 5I, 19 mixed type) to 109 (i-scan; 15B, 8C, 29D, 16E, 5I, 36 mixed type). And 14 patients who had single type by conventional endoscopy were converted to mixed type after i-scan. Therefore, 29 of 156 patients were upgraded after i-scan, they were account for 19% (p<0.0001; 95% confidence interval, 0.13 to 0.25). CONCLUSIONS: The use of i-scan endoscopy significantly improves the identification of minimal change and helps to identify more precisely the type of minimal change.

Recent Advances in Image-enhanced Endoscopy

The desire to better recognized such malignancies, which may be difficult to distinguish from inflammation or trauma, has accelerated the development of endoscopy with new optical technologies. Narrow-band imaging is a novel endoscopic technique that may enhance the accuracy of diagnosis using narrow-bandwidth filters in a red-green-blue sequential illumination system. Autofluorescence imaging is based on the detection of natural tissue fluorescence emitted by endogenous molecules. I-scan technology using a digital filter that modifies normal images through software functions, is the newly developed image-enhanced endoscopic technology from PENTAX. Flexible spectral imaging color enhancement enhances the visualization of mucosal structure and microcirculation by the selection of spectral transmittance with a dedicated wavelength. Confocal laser endomicroscopy images were collected with an argon beam with a scanning depth of 0 (epithelium) to 250 microm (lamina propria) and analyzed using the reflected light.

Timo persistente y su implicancia en el seguimiento del cáncer diferenciado del tiroides / Abnormal mediastinal radioiodine uptake due to persistent thymus: report of one case

We report a 37 years old female operated for a multifocal papillarythyroid carcinoma. During her follow up, mediastinal uptake of radioiodine due to a persistent thymus, was detected. Thisis a situation may cause a false positive uptake of radioiodine that may be interpreted as a tumor relapse or metastasis.

The Current Status of Virtual Chromoscopy / 대한소화기내시경학회지

Virtual chromoscopy is a novel technology that enhances endoscopic visualization of superficial mucosal surfaces and microvascular architecture. Currently available virtual chromoscopy techniques include narrow band imaging, Fujinon intelligent color enhancement and I-scan. Refinements are expected to improve detection of the lesions, which will lead to further insight into the pathological processes, in turn, providing guidance in selecting the optimal treatment. Presently, we review the currently available literature regarding virtual chromoscopy and provide technical principles, clinical usefulness, and limitations.

Molecular Diagnosis of Recurrent Thyroid Cancer by Reverse Transcription-Polymerase Chain Reaction of Thyroglobulin Messenger Ribonucleic Acid in Peripheral Blood / 대한내분비학회지

BACKGROUND: Differentiated thyroid cancer is the most common endocrine malignancy. Despite advances in the treatment of thyroid cancer, disease recurrence and metastasis may occur in as many as 20% of patients, and so continues to pose major problems in its clinical management. Serum thyroglobulin (Tg) measurements, by immunoassay, are used to detect residual or recurrent thyroid cancer following thyroid ablation. However, the usefulness of immunoassay is limited by both the requirement for thyroid hormone withdrawal, to attain optimal test sensitivity, and interference by the antithyroglobulin antibody (Anti-Tg Ab). Recent studies have reported the clinical usefulness of reverse transcription-polymerase chain reaction (RT-PCR) detection of Tg mRNA in the peripheral blood of patients with differentiated thyroid carcinomas. We performed this study to evaluate the usefulness RT-PCR of Tg mRNA in peripheral blood of patients with thyroid carcinoma following a total thyroidectomy and radioiodine ablation therapy. METHODS: Forty cases that underwent a total thyroidectomy and radioiodine ablation therapy were included in this study. Of the 40 patients, 35 were papillary carcinomas and 5 were follicular carcinomas. Ten normal control subjects were also studied. Tg mRNA was extracted. Then RT-PCR, and nested RT-PCR, were run with specific Tg primers. Concurrently, DNA sequencing of the isolates was carried out to prove the isolates were identical to the nucleotide sequence of the Tg. RESULTS: The Tg was detected in 4 of 19 patients, with either a residual thyroid bed, or metastasis, on a 131I whole body scan and in 1 of 21 patients with a negative radioiodine scan. Surprisingly, the Tg mRNA was detected in all the patients and normal controls. CONCLUSION: From our results we can not recommend Tg mRNA, detected by RT-PCR in peripheral blood, as a tumor marker superior to that of the Tg serum level. We consider an intensive re-evaluation of the method is required before considering its clinical applications.

FDG-PET as a Predictor of Recurrence with 131I Scan Negative Differentiated Thyroid Cancer: An Evaluation Compared with Pathologic Findings / 대한내분비학회지

BACKGROUND: FDG-PET has been suggested to have a supplementary role in localizing recurred sites of differentiated thyroid carcinoma. This study was performed to show whether FDG-PET is feasible as an alternative diagnostic modality for patients with I-131 scan negative thyroid carcinoma by verification of post-surgical pathology findings. METHODS: Eighteen patients of papillary thyroid carcinoma (M:F=4:14, age 41+/-16 year) who had total thyroidectomy and I-131 ablation therapy were included. All patients showed negative I-131 scan on therapeutic dose but they were suspected as disease recurrence because of elevated serum Tg or anti-Tg Ab during follow-up periods. FDG-PET was performed, and then cervical lymph node dissection on either side or both sides of the neck was done according to FDG-PET results. RESULTS: A total of 77 cervical lymph node groups were dissected in 18 patients; internal jugular chain 49, spinal accessory 9, jugulodigastric 5, anterior jugular 4, paratracheal 3, supraclavicular 2, and others 5. Forty eight lymph node groups revealed metastatic papillary carcinoma on pathology and their largest diameter ranged from 0.4 to 7.0cm (1.2+/-0.7cm). All patients had at least one malignant lymph node group. FDG-PET detected 37 among 48 malignant lymph nodes (sensitivity 77%), and their count ratio ranged 1.7-31.1 (6.1+/-6.3). Among the 30 malignant lymph nodes less than 1cm, FDG-PET detected 20 lymph nodes. Of the 29 lymph node groups without malignant cells, FDG-PET was also negative in 24 groups (specificity S3%). Positive predictive value of FDG-PET on I-131 scan negative differentiated thyroid carcinoma was 88%; negative predictive value was 69%. CONCLUSION: FDG-PET has been confirmed as a valuable diagnostic modality to detect cervical lymph nodes of differentiated thyroid carcinoma who are suspicious for recurrence but with negative I-131 scan, by pathologic findings.

Comparosin of Pretreatment and Postreatment Whole Body Iodine-131 Scans in Patients with Differentiated Thyroid Carcinoma / 대한내분비학회지

BACKGROUND: Whole body 131I scan is routinely performed in the postoperative evaluation of patients with differentiated thyroid carcinoma to detect recurrence and functioning metastasis. Previous reports suggested that posttreatment whole body scan had higher rate of detecting metastatic lesions that were not visualized by pretreatment images. We observed the frequency of discordance of the two scans and analysed the clinical significances. METHODS: Forty-one patients with differentiated thyroid carcinoma underwent radioactive iodine-131 whole body scans after administration of diagnostic dose (4 mCi) and then therapeutic dose (100~200 mCi of iodine-131). The median age of the patients was 46.9 +/- 15.7 years (range, 17~76). RESULTS: In 16 of the 41 patients (39.0%), pretreatment scan showed additional uptakes that were not seen in the pretreatment scan. Serum thyroglobulin was elevated in 13 of the 16 patients. Of the 22 patients who had been received radioactive iodine therapy previously, eight patients showed new additional lesions in the therapeutic scans but there was no significance according to the history of radioactive iodine therapy, Addisional uptakes after therapeutic dose were noted in neck area in 9 cases, lung in 2 cases, bone in 4 cases and mediastinum in one case. Diffuse hepatic uptake was definitely seen in 7 cases and there were 2 cases whose scans showed liver uptake without any thyroid uptake. CONCLUSION: Posttreatment whole body scan is more sensitive to detect residual tissues and metastasis compared to the usual pretreatment diagnostic whole body scan, and it is suggested that posttreatment whole body scan should be routinely performed after 'I therapy in patients with differentiated thyroid carcinoma for exact evaluation.

Thallium-291 Whole Body Scintigraphy in Postoperative Follow-up of Differentiated Thyroid Carcinoma / 대한내분비학회지

BACKGROUND: The advantages of thallium (Tl)-201 whole body scan in follow-up of patients with thyroid carcinoma include no need to discontinue thyroid hormone replacement, a shorter period of time between injection and imaging, a lower radiation dose, and preservation of affinity for subsequent therapeutic dose of 131I. To evaluate the reliability of whole body scintigraphy using Tl-201 in postoperative follow-up of thyroid carcinoma, this procedure was performed in patients after total thyroidectomy for thyroid carcinoma. The results were compared with those of 131I scintigraphy. METHODS: One hundred nineteen cases (119 patients) with a median age of 43 years (range, 20 85 years) were included in the study. After optimal endogenous thyroid-stimulating hormone stimulation (>50 mIU/mL), 131I (4 mCi) scan and Tl 201 (3 mCi) scan were simultaneously performed. Concomitantly serum thyroglobulin and anti-thyroglobulin antibody levels were checked. If abnormal findings on any of the scintigraphic methods or high levels of thyroglobulin (> 10 ng/mL) were detected, high dose (150~200mCi) 131I was administered as therapy and then whole body scans were performed repeatedly after the therapy. The presence or absence of thyroid cancer was established by pathologic, radiologic, and/or high dose 131I scan findings. RESULTS: In 12 patients, ll-201 scan revealed positive accumulations which were not found on 131I scan, of whom 9 had elevated thyroglobulin levels. In these cases, 5 cases were interpreted to have normal thyroid remnant and 7 cases showed pathologic findings (1 lung, 2 lymph node, 1 bone, and 2 lung and lymph node metastasis, and 1 false positive accumulation of thallium). Metastasis were confirmed histologically in 2 and radiologically in 5 cases. Negative Tl-201 scans, despite of positive 131I scans, occurred in 20 patients, of whom 6 had abnormal thyroglobulin levels. Seventeen cases were interpreted to have thyroid remnant, 2 cases were diagnosed to have thyroid carcinoma metastasis (1 lung, 1 lung and lymph node), and 1 case was not confumed. CONCLUSION: These results suggest that 131I scan is superior to 11-201 scan for detection of residual or metastatic differentiated thyroid carcinoma. However, the use of combined modalities may provide a higher diagnostic yield. TI-201 scan can be useful especially in cases in which 'I scan is negative despite of abnormal thyroglobulin levels.