Abstracts OPT12-005 Algorithmic Approaches to the Diagnosis of Gallbladder Intraluminal Lesions on Ultrasonography Chia-Hung Wu,1 Yukun Luo,2 Xiang Fei,2 Yi-Hong Chou,1 Hong-Jen Chiou,1 Hsin-Kai Wang,1 Yi-Chen Lai,1 Yung-Hui Lin,1 Chui-Mei Tiu,1 Jane Wang1 1 Department of Radiology, Taipei Veterans General Hospital, Taiwan, 2 Department of Ultrasound, The General Hospital of People’s Liberation Army, Beijing, China Objectives: To summarize the algorithmic approach to the diagnosis of polypoid lesions of the gallbladder on ultrasonography. Methods: We reviewed the imaging database from the picture archiving and communication system (PACS) in our hospital. After extensive literature review, typical ultrosonographic characteristics with pathological diagnosis were categorized according to the proposed algorithmic approaches flowchart. Our recent experiences in contrast-enhanced ultrasonography are also described. Results: Polypoid lesions of the gallbladder are common findings at abdominal ultrasonography. The term ‘‘polypoid’’ is defined as a focal elevation or a protrusion into the gallbladder lumen from the wall. However, not all polypoid lesions are malignant. In fact, most of the incidentally found polypoid lesions in the gallbladder are benign. Since most malignant tumors in the gallbladder are asymptomatic and usually diagnosed when advanced, differentiation between malignancy and benignity is crucial. Mellnick VM, et al. classified different spectrums of the gallbladder lesions into pseudotumors, benign tumors and malignant tumors. To evaluate a gallbladder polypoid lesion on ultrasonography, we suggest to confirm a ‘‘true’’ polypoid lesion first. After a ‘‘true’’ polypoid lesion is established, the next step is to distinguish pseudotumors from true tumor lesions. Finally, the differential diagnoses should be grouped into benign and malignant tumors separately. Several clinical factors have also been described to aid the differential diagnosis, including age, comobilidities and presence of clinical symptoms. The algorithmic diagnostic approach of gallbladder polypoid lesions is addressed. Conclusions: Ultrasonography is the first-line diagnostic tool for gallbladder polypoid lesions. It is important for radiologists to understand imaging characteristics of these lesions. OPT12-006 Utility Of Endoanal Ultrasound In Evaluation of Patients with Anorectal Abscess Hae Jeong Jeon,1 Mi Hye Yu,1 Hee Sun Park,1 Young Jun Kim,1 Sung Il Jung,1 Sang Woo Park,1 Ung Chae Park2 1 Department of Radiology, Konkuk University, School of Medicine, South Korea, 2Department of General Surgery, School of Medicine Konkuk University Objectives: Study was to assess the accuracy of endoanal ultrasonography for preoperative assessment of anorectal abscess(ARA) with reference to the types. Specifically, availability as a surveillance tool to monitor the residual or missed secondary(daughter) abscess after primary operation, was evaluated. Methods: 283 patients with ARA had the operation. All patients underwent pre and post-operative physical examination and endoanal ultrasonography. Agreement between the physical and endosonographic findings and the surgical findings were evaluated with reference to 4 types of classification; perianal(PA), ischiorectal(IR), intersphincteric(IS), supralevator(SL) type of abscesses. The changes and differences in findings of endosono-
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graphic assessment between pre and post-operative periods were also evaluated. Results: The incidence of the sonographic subtypes were; PA5 178(62.9%); IR5 68(24.0%); IS5 20(7.1%); SL type5 17(6.0%). Overall accuracy of ultrasonography was significantly higher than that of physical examination in detecting the primary abscess (92.8% vs. 83.0%, respectively, p , 0.01). The accuracy was as follows: sensitivity, 95 percent; specificity, 68 percent; positive predictive value, 91 percent; negative predictive value, 65 percent. Localization of IR type with horseshoe extension(n514) and distantly positioned SL type(n510) were attributed to the low value of specificity and negative prediction. Conclusions: Endoanal ultrasonography is reliable and useful for pre and post-operative localization and assessment of ARA. Specifically, endoanal ultrasound quickly gained usefulness for monitoring residual or missed secondary abscess pocket after primary operation. OPT12-007 Local Phase-Based Anisotropic Diffusion for Speckle Reduction Hai Zhang,1 Wangming Wei2 1 Department of Ultrasound Image, Department of Ultrasonography Image, Shenzhen People’s Hospital, The Second Affiliated Hospital of Jinan University Guangdong, China, 2Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences Objectives: Speckle in ultrasound images could be a useful pattern for tracking important structures, such as dilatate bile ducts and gallbladder, polycystic liver and multiple large hydatid cysts of liver, but may also be an annoying noise that degrades the image quality. This paper proposes an adaptive diffusion process to enhance the quality of ultrasound images by reducing the speckle noise while simultaneously preserving the features in the image, so as to simplify the use of ultrasound images in clinical diagnosis and therapy. Methods: We incorporate a local phase-based edge detector, called feature asymmetry (FA), into the forward-and-backward diffusion. Unlike intensity-based operators, the FA measurement is theoretically intensity-invariant and it can effectively discriminate the edges from noise even if they have similar gradient. Attributing to this property, forward diffusion is promoted in speckled regions while smoothing is prohibited on the edges, resulting in feature preserving speckle reduction. Meanwhile, the backward diffusion in the proposed method can better protect the intensity contrasts of different features by reserving the diffusion process happened at features. In addition, the parameters involved are automatically computed in order to enhance the robustness of our method so that it can be adapted to different images without repetitive parameter tuning. Results: We validate the performance of the proposed method with many clinical ultrasound images, and evaluate the segmentation accuracies on the despeckled results. Specifically, we compare our method with several state-of-the-art speckle reduction filters: SRAD, OBNLM, SUSAN AD and ADLG. Experimental results show that our method greatly reduces the noise and best preserves the boundaries of important structures. Furthermore, the segmentation results on despeckled images are evaluated with two widely used metrics: Hausdorff distance (HD) and average minimum Euclidean distance (AMED). Small values of HD and AMED indicate high segmentation accuracy. As can be seen in the experiments, our method achieves the lowest values of HD and AMED measurements, indicating best performance.
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Conclusions: In this paper, we propose a new variant of anisotropic diffusion for speckle reduction by integrating a local phase-based edge detector to guide the diffusion processing. Our method can suppress the noise and maintain the features in the image as the FA measurement can guide the forward-and-backward diffusion to perform despeckling adaptively. The robustness of the proposed method is further improved by automatically computing the parameters that affect the performance. OPT12-008 Sonographic Findings of Xanthogranulomatous Cholecystitis: A Pictorial Review Tan Gaik Mooi, Teo Si Min, Low Su Chong Albert, Lim Sze Ying Department of Diagnostic Radiology, Singapore General Hospital, Singapore Objectives: Xanthogranulomatous cholecystitis(XGC) is a rare inflammatory disease of the gallbladder characterised by a focal or diffuse destructive inflammatory process, with accumulation of acute and chronic inflammatory cells, fibrous tissues, and lipid laden macrophages. Its significance lies in the fact that it is a benign disease that is difficult to differentiate from gallbladder carcinoma which has a poor prognosis.1 Ultrasound nevertheless is a useful screening tool for suspected gallbladder pathology.The purpose of this exhibit is to:1. Describe the sonographic appearances of XGC and2. Present the corresponding CT, MRI or histological findings, with a review of the literature. Methods: We identified six cases of XGC with ultrasound in our institution between August 2009 and April 2017, five of which were confirmed on histology and one diagnosed based on serial imaging. A review of the literature was also made. Results: Focal or diffuse thickening of gallbladder wall as well as co-existence of gallstones, was seen in all cases, which concurred with those reported in the literature. We observed marked gallbladder mural thickening of . 10 mm thick with hypoechoic intramural nodules in all cases. The mural thickening could be symmetrical or asymmetrical, with varied degrees of echogenicity. Conclusions: While the diagnosis of XGC remains challenging on imaging, a better understanding of its sonographic appearances will increase its awareness and potentially enable a more accurate preoperative diagnosis that is essential in surgical planning and better patient outcome. OPT12-009 Diagnosis of Pancreatic Neuroendocrine Tumors with Endoscopic Ultrasound - A Rare Case of Multiple Endocrine Neoplasia Type 1 (Men-1 Syndrome) Chen-Wang Chang, Hsaing-Hung Lin, Cheng-Hsin Chu, Horng-Yuan Wang, Ming-Jen Chen Department of Gastroenterology and Hepatology, MacKay Memorial Hospital, Taiwan Objectives: Pancreatic neuroendocrine tumors (PNETs), one of MEN 1, is a rare disease. Early diagnosis of PNETs is difficult. Methods: A case of PNETs was included. Results: A 54-year-old female was a patient with past history of type 2 DM, hypertension for a long time and regular follow up in our hospital. Her mother also had past medical history of rectal adenocarcinoma post surgical resection and advanced pancreatic adenocarcinoma post gastrojejunostomy. Seven years ago, she had abdominal fullness and abdomen l ultrasound revealed an anechoic lesion about 5.8mm in the pancreatic head. Abdominal computed tomography showed several subcentimeter low densities at pancre-
Volume 43, Number S1, 2017 atic head and body and pancreatic cysts was impressed. However, the size of the pancreatic cystic lesions increased and up to 1.3cm in abdominal CT. CA 199 1.05 U/mL and CEA 2.11 ng/ mL were found. Endoscopic Ultrasound showed multiple anechoic to hypoechoic nodule in the pancreas, size up to 12.8x10.9 mm and pancreatic neuroendocrine tumors was diagnosed after fine needle aspiration. Two hyperfunctioning parathyroid glands in parathyroid scan and a pituitary microadenoma (5*7mm) were also found in the patient. Thus multiple endocrine neoplasia type 1 (MEN 1) was diagnosed. Conclusions: MEN 1 is a rare disorder that causes tumors in the endocrine glands and parts of the GI tract. The tumors are usually benign. A mutation in a tumor suppressor gene on chromosome 11q13, leads to hyperplastic and neoplastic disorders of endocrine organs, including the parathyroid gland (95 %), anterior pituitary gland (30%), and pancreas. Pancreatic neuroendocrine tumors (PNETs) are found in 30%– 75% of patients with MEN1 and are most often nonfunctional. An early diagnosis and timely intervention is thought to lead to a better long-term outcome. Endoscopic ultrasound (EUS) is the most sensitive tool to screen for PNETs and enables visualization of small lesions, like our case, that are frequently missed with computed tomography, magnetic resonance imaging (MRI), or somatostatin receptor scintigraphy. OPT12-010 Spectrum of Ultrasound Findings of Premalignant Cholangiocarcinomas Surachate Siripongsakun, Sirachat Vidhyarkorn Department of Diagnostic Radiology, Chulabhorn Hospital, Thailand Objectives: To study spectrum of sonographic findings of cholangiocarcinoma premalignant lesions including Biliary Intraepithelial Neoplasm (Bil-IN) and Intraductal Papillary Neoplasm of Biliary tract (IPNB). Methods: Ultrasonography (US) finding of the pathologic proved Bil-IN and IPNB are collected and analyzed from our ongoing cohort of cholangiocarcinoma surveillance program at Ban-Luang districted, Nan province, Northern Thailand, which involves 4,200 populations who are age between 30-60 in Ban Luang district. Liver ultrasonography is performed every 6 months for cancer detection and the patient with abnormal finding will be sent for CT/ MRI/MRCP studies and subsequently surgery for cholangiocarcinoma suspicious lesions. Results: At present of 4 years surveillance period, there are 7 and 6 cases of premalignant lesions proved cases of Bil-IN and IPNB respectively. US finding of Bil-IN includes focal bile duct narrowing without mass, cystic dilatation peripheral bile duct and focal bile duct obstruction associated with parasitic egg or cell debris.IPNB presents as focal bile duct dilatation without cause of obstruction, complex cystic lesion with demonstrable connection to biliary system orintraductal nodule which all of them are hyperechogenic. The echogenic nodule from IPNB may present at tubular-shaped due to bile ductal alignment. Conclusions: US findings of premalignant lesions of cholangiocarcioma varies and majority non-specific. Understanding disease spectrum of premalignant cholangiocarcioma lesions on US may help improve early detection. OPT12-011 Pancreas Ultrasound among Young Adult Diabetes Melitus Type II with Abdominal Tuberculosis Maria Goretti Ametembun
