Radiologic Findings of Childhood Lower Respiratory Tract Infection by Influenza Virus

PURPOSE: After the RS (respiratory syncytial) virus, the influenza virus is the most common cause of childhood lower respiratory tract infection. We assessed the radiologic findings of childhood lower respiratory tract infection by the influenza virus. MATERIALS AND METHODS: A total of 105 pediatric patients (76 males and 29 females; mean age, 2.4 years) with symptoms of respiratory tract infection were examined between March 1997 and April 2000. Nasopharyngeal aspirates were obtained and influenza virus infection was confirmed by direct or indirect immunofluorescent assays. Peribronchial infiltration, hyperinflation, atelectasis, pulmonary consolidation, and hilar lymphadenopathy were evaluated retrospectively at simple chest radiography. RESULTS: Bilateral perihilar peribronchial infiltration was noted in 78.1% of patients (n=82), hyperinflation in 63.8% (n=67), atelectasis in 3.8% (n=4; segmental 50%, lobar 50%), and pulmonary consolidation in 16.2% [n=17; segmental 70.6% (n=12), lobar 29.4% (n=5)]. Hilar lymphadenopathy was noted in one patient in whom there was no pleural effusion, and subglottic airway narrowing in 12 of 14 in whom the croup symptom complex was present. CONCLUSION: The major radiologic findings of influenza virus infection were bilateral perihilar peribronchial infiltration and hyperinflation. In some patients, upper respiratory tract infection was combined with subgolttic airway narrowing. Atelectasis or pleural effusion was rare.

Primary Retroperitoneal Synovial Sarcoma: A Case Report

A case of a 36-yr-old woman with retroperitoneal synovial sarcoma is described. Her presenting symptom was epigastric pain that radiating to the back. On radiologic study, bulky retropancreatic soft tissue mass was detected which showed cystic and solid components. At operation, complete resection of the tumor was not possible because of the adhesion to the vena cava and the liver. During the follow-up, extensive tumor recurrence and liver metastasis were revealed. Primary retroperitoneal synovial sarcoma is a very rare malignant tumor with high mortality and recurrence rates. Retroperitoneal synovial sarcoma usually appears as a nonspecific soft tissue mass that do not have specific imaging features differentiating it from other mesenchymal tumors. However general radiologic findings and anatomic location of the tumor may help the diagnosis. In addition, synovial sarcoma should be included in the differential diagnosis of retroperitoneal soft tissue mass detected in young adults.

Radiofrequency Thermal Ablation of Benign Cystic Lesion:An Experimental Pilot Study in a Porcine Gallbladder Model

PURPOSE: To determine whether radiofrequency thermal ablation can be used to treat benign cystic lesions in a porcine gallbladder model. MATERIALS AND METHODS: This experimental study of radiofrequency thermal ablation involved the use of 15 exvivo porcine gallbladders and 15-G expandable needle electrodes. To investigate optimal temperature parame-ters,three groups of five were designated according to target temperature: Group A: 70 degrees C; Group B: 80 degrees C; Group C: 90 degrees C. After the target temperature was reached, ablation lasted for one minute. Gallbladder width, height and length were measured before and after ablation, and the estimated volume reduction ratios of the three groups were compared. Whether adjacent liver parenchyma around the gallbladder fossa was ablated by heat conducted from hot bile was also determined, and the thickness of the ablated area of the liver was measured. RESULTS: The volume reduction ratio in Group A, B and C was 42.7%, 41.7% and 42.9%, respectively (p>.05). In all 15 cases, gallbladder walls lost their transparency and elasticity at about 70 degrees C. In nine of ten cases in Groups B and C, the hepatic capsule around the gallbladder fossa was retracted at about 80 degrees C. The mean thickness of liver parenchymal damage adjacent to the gallbladder was 5.4 mm in Group B and 9.8 mm in Group C. In Group A livers, only one case showed minimal gradual parenchymal change. Microscopically, all three groups showed complete coagulation necrosis of the wall. CONCLUSION: On the basis of this feasibility study, radiofrequency thermal ablation is potentially suitable for the ultrasound-guided treatment of symptomatic cystic lesions including benign hepatic or renal cyst.