Development of a World Wide Web-based Interactive Education Program to Improve Detectability of Pulmonary Nodules on Chest Radiographs

PURPOSE: To design and develop a World Wide Web-based education program that will allow trainees to interactively learn and improve the diagnostic capability of detecting pulmonary nodules on chest radiographs. MATERIALS AND METHODS: Chest radiographs with known diagnosis were retrieved and selected from our institutional clinical archives. A database was constructed by sorting radiographs into three groups: normal, nodule, and false positive (i.e., nodule-like focal opacity). Each nodule was assigned with the degree of detectability: easy, intermediate, difficult, and likely missed. Nodules were characterized by their morphology (well-defined, ill-defined, irregular, faint) and by other associated pathologies or potentially obscuring structures. The Web site was organized into four sections: study, test, record and information. RESULTS: The Web site allowed a user interactively to undergo the training section appropriate to the user's diagnostic capability. The training was enhanced by means of clinical and other pertinent radiological findings included in the database. The outcome of the training was tested with clinical test radiographs that presented nodules or false positives with varying diagnostic difficulties. CONCLUSION: A Word Wide Web-based education program is a promising technique that would allow trainees to interactively learn and improve the diagnostic capability of detecting and characterizing pulmonary nodules.

Inhibitory and Eliminating Effects of Yeast-extracted Melanoston on Pigmentation and Preexisting Pigmentation, Respectively / 대한피부과학회지

BACKGROUND: Melanoston is a new melanogenesis inhibitor isolated from yeast. However, little is known about the mechanism of this agent in melanogenesis and also its clinical effectiveness on hyperpigmented lesions. OBJECTIVE: The purpose of this study was to examine the inhibitory effect of melanoston on in vivo activity of tyrosinase. METHODS: We assessed tyrosinase activity, which participates in the synthesis of melanin pigment and resides in melanocytes of guinea pig's epidermis, using immunohistochemical methods after application of 0.1% and 0.01% melanoston on the skin of guinea pigs. We also conducted an 8-week clinical trial on 30 women volunteers to determine the clinical efficacy and safety of melanoston. Participants were instructed to apply melanoston and vehicle on 7 small areas of skin on both forearms for 8 weeks, before and after UVB exposure, and they were examined daily for the first week, then weekly thereafter. RESULTS: The lowest level of tyrosinase activity was observed at the 3rd week after application of 0.1% and 0.01% melanoston on the skin of guinea pigs, and melanoston had a relatively strong inhibitory effect on tyrosinase, as compared with vehicle and arbutin. Differences in the degree of pigmentation between areas treated with 0.5% melanoston and application of vehicle only, and between before and after UVB exposure were considered to be significant (p<0.001, on each time). CONCLUSION: We conclude that melanoston has an inhibitory effect on melanogenesis and some eliminating effect on preexisting pigmentation.

Traumatic Intracranial Aneurysms in Children

PURPOSE: To describe the imaging findings of traumatic intracranial aneurysms (TICA) in children. MATERIALS AND METHODS: Five boys aged 3-15 (mean, 7) years with surgically confirmed TICA were included in this study. All had a history of nonpenetrating head trauma, and they underwent precontrast CT imaging immediately after the injury and follow-up CT or MRI. In all cases, angiography revealed the presence of aneurysms, which at surgery were shown to be pseudoaneurysms with severe adhesions. RESULTS: Angiography demonstrated that all aneurysms were located in the anterior cerebral artery (ACA) or its branches. The precise locations were the A2 segment of the ACA, the site of origin of the callosomarginal artery or its first branch, or of the anterior internal frontal artery, or between the first and second branch of the pericallosal artery. In all patients, precontrast CT performed immediately after trauma depicted subarachnoid hemorrhage (SAH) in the anterior interhemispheric fissure (AIHF). Follow-up precontrast CT showed nodular high density around the anterior falx in three, recurrent SAH in the AIHF in two, and intracerebral hemorrhage (ICH) with intraventricular hemorrhage in two. In two patients with a nodular high-density lesion, nodular enhancement was demonstrated at postcontrast CT, and in one, follow-up MRI revealed a nodular signal void around the anterior falx; nodular enhancement was seen at postcontrast imaging, and MR angiogram depicted a saccular aneurysm. In one patient, MRI demonstrated infarction in the caudate nucleus and ACA territory. CONCLUSION: If, after head injury, an area of nodular high density is revealed by CT, or a signal void by MRI, or if SAH or ICH is present around the anterior falx, the possibility of TICA should be considered.

Nasopharyngeal Teratoma in an Adult: A Case Report

Nasopharyngeal teratomas are rare congenital tumors which mainly cause neonatal respiratory difficulty or feeding problems. We report an extremely rare case of nasopharyngeal teratoma in which a 34-year-old woman experienced a foreign body sensation. Simple radiographs and CT scans revealed the presence of an exophytically growing mass with a region of fatty attenuation and a well-formed tooth in the nasopharyngeal wall. The mass was surgically removed, and found at histopathology to be a mature teratoma.

Mediastinal Lipoblastoma in a Child: A Case Report

Lipoblastoma is a benign tumor which frequently arises in the limbs but rarely in the mediastinum, and is common in children under the age of three years. We report a case of mediastinal lipoblastoma in a 27-month-old female child complaining of dyspnea. Plain radiography demonstrated a huge well-defined mass in the me-diastinum, while CT scanning revealed a soft tissue mass with an internal hypodense portion. When radi-ographic images in children under the age of three reveal a soft tissue mass with a fat component in the mediastinum, especially where there is no calcification or a cystic component, lipoblastoma should be included in the differential diagnosis.

Ductal Adenocarcinoma Arising from Heterotopic Pancreas in the Stomach: A Case Report

Malignant transformation of heterotopic pancreas is extremely rare. We report a case of ductal adenocarcinoma arising from heterotopic pancreas in the stomach of a 64-year-old man. Preoperative CT scans showed the lesion as a submucosal mass along the greater curvature of the pyloric antrum and protruding into the pyloric canal. After gastric surgery, the resected tumor was histopathologically diagnosed as a ductal adenocarcinoma arising from heterotopic pancreas with cystic dilatation of aberrant pancreatic duct.