Seong Whi Cho

Pretreatment Evaluation with Contrast-Enhanced Ultrasonography for Percutaneous Radiofrequency Ablation of Hepatocellular Carcinomas with Poor Conspicuity on Conventional Ultrasonography

OBJECTIVE To determine whether pretreatment evaluation with contrast-enhanced ultrasonography (CEUS) is effective for percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) with poor conspicuity on conventional ultrasonography (US). MATERIALS AND METHODS This retrospective study was approved by the institutional review board and informed consent was waived. From June 2008 to July 2011, 82 patients having HCCs (1.2 ± 0.4 cm) with poor conspicuity on planning US for RFA were evaluated with CEUS prior to percutaneous RFA. We analyzed our database, radiologic reports, and US images in order to determine whether the location of HCC candidates on planning US coincide with that on CEUS. To avoid incomplete ablation, percutaneous RFA was performed only when HCC nodules were identified on CEUS. The rate of technical success was assessed. The cumulative rate of local tumor progression was estimated with the use of the Kaplan-Meier method (mean follow-up: 24.0 ± 13.0 months). RESULTS Among 82 patients, 73 (89%) HCCs were identified on CEUS, whereas 9 (11%) were not. Of 73 identifiable HCCs on CEUS, the location of HCC on planning US corresponded with that on CEUS in 64 (87.7%), whereas the location did not correspond in 9 (12.3%) HCCs. Technical success was achieved for all 73 identifiable HCCs on CEUS in a single (n = 72) or two (n = 1) RFA sessions. Cumulative rates of local tumor progression were estimated as 1.9% and 15.4% at 1 and 3 years, respectively. CONCLUSION Pretreatment evaluation with CEUS is effective for percutaneous RFA of HCCs with poor conspicuity on conventional US.

Sonography of the first metatarsophalangeal joint and sonographically guided intraarticular injection of corticosteroid in acute gout attack.

The aims of this study were to identify the characteristic ultrasound (US) findings of the first metatarsophalangeal joint (MTPJ1) in acute gout attack and to evaluate the efficacy and safety of US‐guided intraarticular corticosteroid injection of the MTPJ1.

Terahertz imaging of metastatic lymph nodes using spectroscopic integration technique

Terahertz (THz) imaging was used to differentiate the metastatic states of frozen lymph nodes (LNs) by using spectroscopic integration technique (SIT). The metastatic states were classified into three groups: healthy LNs, completely metastatic LNs, and partially metastatic LNs, which were obtained from three mice without infection and six mice infected with murine melanoma cells for 30 days and 15 days, respectively. Under histological examination, the healthy LNs and completely metastatic LNs were found to have a homogeneous cellular structure but the partially metastatic LNs had interfaces of the melanoma and healthy tissue. THz signals between the experimental groups were not distinguished at room temperature due to high attenuation by water in the tissues. However, a signal gap between the healthy and completely metastatic LNs was detected at freezing temperature. The signal gap could be enhanced by using SIT that is a signal processing method dichotomizing the signal difference between the healthy cells and melanoma cells with their normalized spectral integration. This technique clearly imaged the interfaces in the partially metastatic LNs, which could not be achieved by existing methods using a peak point or spectral value. The image resolution was high enough to recognize a metastatic area of about 0.7 mm size in the partially metastatic LNs. Therefore, this pilot study demonstrated that THz imaging of the frozen specimen using SIT can be used to diagnose the metastatic state of LNs for clinical application.

Features of Pure Lobular Carcinoma In Situ on Magnetic Resonance Imaging Associated with Immediate Re-Excision after Lumpectomy

Purpose To evaluate imaging features of pure lobular carcinoma in situ (LCIS) on magnetic resonance imaging (MRI) in patients who underwent immediate re-excision after lumpectomy. Methods Twenty-six patients (46.1±6.7 years) with 28 pure LCIS lesions, who underwent preoperative MRI and received curative surgery at our institution between 2005 and 2013, were included in this study. Clinicopathologic features associated with immediate re-excision were reviewed and analyzed using Fisher exact test or the Wilcoxon signed rank test. Results Of the 28 lesions, 21.4% (6/28, six patients) were subjected to immediate re-excision due to resection margin involvement by LCIS. Nonmass lesions and moderate-to-marked background parenchymal enhancement on MRI were more frequently found in the re-excision group than in the single operation group (100% [6/6] vs. 40.9% [9/22], p=0.018; 83.3% [5/6] vs. 31.8% [7/22], p=0.057, respectively). The median lesion size discrepancy observed between magnetic resonance images and histopathology was greater in the re-excision group than in the single operation group (-0.82 vs. 0.13, p=0.018). There were no differences in the mammographic or histopathologic findings between the two groups. Conclusion Nonmass LCIS lesions or moderate-to-marked background parenchymal enhancements on MRI can result in an underestimation of the extent of the lesions and are associated with subsequent re-excision due to resection margin involvement.

Pancreatic Neuroendocrine Tumor Presenting as Acute Pancreatitis

We report a case of acute pancreatitis secondary to pancreatic neuroendocrine tumor. A 46-year old man presented with upper abdominal pain. The serum amylase and lipase were elevated. Abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography revealed a 1.7 cm sized mass at the pancreas body with a dilatation of the upstream pancreatic duct and mild infiltrations of peripancreatic fat. An endoscopic ultrasound-guided fine needle biopsy was performed for the pancreatic mass, but only necrotic tissue was observed on the pathologic examination. A chest and neck CT scan revealed anterior mediastinal, paratracheal, and cervical lymph node enlargement, which were indicative of metastasis. An ultrasound-guided core needle biopsy was performed for the enlarged neck lymph node, and pathologic examination revealed a metastatic poorly differentiated carcinoma. Immunohistochemical analysis showed positive staining for synaptophysin, chromogranin A, and CD 56, indicative of a neuroendocrine carcinoma.

Percutaneous cholecystostomy for biliary decompression in patients with cholangitis and pancreatitis

Objective This study was performed to assess the effectiveness and safety of percutaneous cholecystostomy (PC) for biliary decompression. Methods We retrospectively analyzed our institution’s PC database from March 2015 to August 2017 and selected patients with biliary obstruction. The primary outcomes were the technical and clinical success rates. As secondary outcomes, adverse events and pain after PC were compared with those of patients who underwent PC for acute cholecystitis during the same period. Results Twenty patients underwent PC for biliary obstruction (cholangitis, 19; pancreatitis, 1). The technical and clinical success rates were 100%. The median serum total bilirubin level decreased considerably from 4.5 to 1.4 mg/dL after PC. An adverse event (catheter migration) occurred in 1 patient, and 17 patients developed pain after PC. During the same period, 104 patients underwent PC for cholecystitis. Adverse events occurred in 7 patients, and 62 developed pain. There was no significant difference in the adverse event rate between the cholangitis/pancreatitis and cholecystitis groups (5.0% vs. 6.7%, respectively), but pain occurred considerably more frequently in the cholangitis/pancreatitis group (94.4% vs. 63.9%, respectively). Conclusions PC is an effective and safe method for biliary decompression in selected patients. However, attention should be paid to postoperative pain.

Adult Intussusception Caused by Inverted Meckel's Diverticulum Containing Mesenteric Heterotopic Pancreas and Smooth Muscle Bundles.

pISSN 2383-7837 eISSN 2383-7845

Neonatal head ultrasound: systematic approach to congenital Central Nervous System anomalies. A pictorial essay.

Brain ultrasound is widely used for the screening of prematurely born babies. Although the best imaging modality for the central nervous system anomaly is brain MRI, the first imaging study in the post-natal period is brain ultrasonography in most cases. Anomalies could be found incidentally on screening ultrasound, or in those cases already suspected on prenatal ultrasound. In order not to miss congenital structural abnormalities of the brain on screening ultrasound, systematic approaches would be very helpful. The ventricles and sylvian fissures are very important structures to suspect central nervous system anomalies: they are symmetric structures so we should look for any asymmetry or maldevelopment. And then, on sagittal images, the midline structures including the corpus callosum and cerebellar vermis should be observed carefully. Finally, we should look for any abnormality in gyration or cortical development. Skull defect with herniation of intracranial contents, a spectrum of encephalo-meningocele, could be also identified on ultrasound. Congenital infections such as cytomegalovirus infection may show ventriculomegaly and malformation of the cortical development on imaging studies.