Containment Liner Plate Void Defect Detection Technique Using Phased Array Ultrasonic Testing and Acoustic Resonance Method.

The CLP (containment liner plate) of a nuclear power plant protects the internal system from the external environment and sudden changes in internal pressure or temperature, and it is a structure that blocks and protects radioactive materials leaking inside and outside in the event of a nuclear accident and is composed of a liner plate, reinforcing bars, tendons, and concrete. Recently, corrosion on the rear side of the liner plate and concrete voids has emerged as a severe defect in nuclear power plants across South Korea. Therefore, in this study, we proposed a new inspection method that a line-type inspection method applied phased array ultrasonic testing and the area inspection method applied acoustic resonance method using developed moveable tapper. The acoustic signals were signal-processed and reproduced to a mapping image following the inspection area, and with the image, it was possible to determine the type of defect. Furthermore, an automated inspection system for within the CLP was proposed.

Clinically useful diagnostic tool of contrast enhanced ultrasonography for focal liver masses: comparison to computed tomography and magnetic resonance imaging.

BACKGROUND/AIMS: To evaluate the diagnostic value of contrast (SonoVue(®)) enhancement ultrasonography (CEUS) and to compare this method with computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating liver masses. METHODS: CEUS (n=50), CT (n=47), and MRI (n=43) were performed on 50 liver masses in 48 patients for baseline mass haracterization. The most likely impression for each modality and the final diagnosis, based on the combined biopsy results (n=14), angiography findings (n=36), and clinical course, were determined. The diagnostic value of CEUS was compared to those of CT and MRI. RESULTS: The final diagnosis of the masses was hepatocellular carcinoma (n=43), hemangioma (n=3), benign adenoma (n=2), eosinophilic abscess (n=1), and liver metastasis (n=1). The overall diagnostic agreement with the final diagnosis was substantial for CEUS, CT, and MRI, with κ values of 0.621, 0.763, and 0.784, respectively. The sensitivity, specificity, and accuracy were 83.3%, 87.5%, and 84.0%, respectively, for CEUS; 95.0%, 87.5%, and 93.8%, respectively, for CT; and 94.6%, 83.3%, and 93.0%, respectively for MRI. After excluding the lesions with poor acoustic sonographic windows, the sensitivity, specificity, and accuracy for CEUS were 94.6%, 87.5%, and 93.3%, respectively, with a κ value of 0.765. CONCLUSIONS: If an appropriate acoustic window is available, CEUS is comparable to CT and MRI for the diagnosis of liver masses.

Magnifying endoscopy for the diagnosis of specialized intestinal metaplasia in short-segment Barrett's esophagus.

AIM: To determine whether magnified observation of short-segment Barrett's esophagus (BE) is useful for the detection of specialized intestinal metaplasia (SIM). METHODS: Thirty patients with suspected short-segment BE underwent magnifying endoscopy up to × 80. The magnified images were analyzed with respect to their pit-patterns, which were simultaneously classified into five epithelial types [I (small round), II (straight), III (long oval), IV (tubular), V (villous)] by Endo's classification. Then, a 0.5% solution of methylene blue (MB) was sprayed over columnar mucosa. The patterns of the magnified image and MB staining were analyzed. Biopsies were obtained from the regions previously observed by magnifying endoscopy and MB chromoendoscopy. RESULTS: Three of five patients with a type V (villous) epithelial pattern had SIM, whereas 21 patients with a non-type V epithelial patterns did not have SIM. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of pit-patterns in detecting SIM were 100%, 91.3%, 92.3%, 60% and 100%, respectively (P = 0.004). Three of the 12 patients with positive MB staining had SIM, whereas 14 patients with negative MB staining did not have SIM. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MB staining in detecting SIM were 100%, 60.9%, 65.4%, 25% and 100%, respectively (P = 0.085). The specificity and accuracy of pit-pattern evaluation were significantly superior compared with MB staining for detecting SIM by comparison with the exact McNemar's test (P = 0.0391). CONCLUSION: The magnified observation of a short-segment BE according to the mucosal pattern and its classification can be predictive of SIM.