PurposeTo explore the CT features and its diagnostic value of mediastinal congenital bronchogenic cysts.Materials and MethodsThe clinical findings and CT manifestations of 14 patients with mediastinal bronchogenic cysts confirmed by surgery and pathology were retrospectively analyzed, among which 12 were performed by both plain and enhanced CT scan, and the other 2 only received either plain or enhanced CT scan.ResultsAll the patients presentedfluid-filled cysts, and 3 of them had CT number lower than 20 HU, 7 cases from 20 to 60 HU, and 4 more than 60 HU. Four patients had lesions in anterior mediastinum, 4 others in posterior mediastinum, and all the 8 lesions were on the left side; 6 patients had lesions in middle mediastinum, among which 5 lesions were on the right side; and 1 case of posterior bronchogenic cysts cancerated into adenocarcinoma.ConclusionMediastinal bronchogenic cysts can appear in any part of mediastinum; lesions in middle mediastinum are more likely to occur on the right side, whilst lesions in anterior and posterior mediastinum are often located on the left side. The typical CT manifestations show well-defined round or oval masses of homogeneous soft-tissue or cysts with watery density.

Objective To show the distinctive resonance pattern in 7 cases of intracranial abscess and 19 cases of cystic lesions as to evaluating these specific resonance peaks. Methods Characteristics of ~1H-MRS in 7 patients with brain abscesses and 19 with cystic or necrotic intracranial tumors were analyzed and compared. Peak assignment was based on reference values from in vivo and in vitro studies. Results Among 7 patients with brain abscesses, 6 showed the presence of cytosolic amino acid (AA) at 0.9 ppm, 5 showed alanine (Ala) at 1.5 ppm, 2 showed acetate (Ac) at 1.9 ppm and 1 patient showed succinate (Suc) at 2.4 ppm. None of the above resonances had been detected in spectra from 19 cases of cystic or necrotic intracranial tumors. Conclusions ~1H-MRS might reflect the different histochemical specificity of abscesses and cystic or necrotic tumors effectively. It should have special values in diagnosis and differential diagnosis of the brain abscess.

Objective To analyze CT features of xanthogranulomatous cholecystitis(XGC)so that to improve the accuracy of diagnosis.Methods The data of CT,clinic and operation in 11 cases with XGC proved pathologically were analysed.The following CT features were analyzed:the cholecystic wall thickness,intramural hypoattenuated nodules,inner wall,mucosal line,patterns of enhancement of thickened wall,involved liver tissue and the presence of stones.The changes around the gallbladder were also noticed.Results The gallbladder wall was thickened and intramural hypoattenuated nodules were seen in all patients.The inner wall of gallbladder was smooth in 9 patients,the mucosal line was observed in 6 cases,the size of gallbladder was enlarged in 3 while 4 gallbladders were smaller than normal.Stones were found in 4 gallbladders.There were hepatic involvement in 6,pericholecystic infiltration in 3 and dilatation of biliary tract in 6 cases.Conclusion CT features of thickened gallbladder wall with intramural hypoattenuated nodules(sandwich sign)and continuous mucosal line were characteristic of XGC.

Purpose To explore the CT features of mediastinal cystic mature teratoma. Materials and Methods CT images of 11 patients with pathologically confirmed mediastinal cystic mature teratoma were retrospectively analyzed, distribution within mediastinum, shape of cysts, capsule contents density, walls of cysts and mass cardiovascular interface (MCI) were analyzed. Results All the 11 cases were located in the anterior mediastinum, including three cases confined to the anterior mediastinum, seven cases located mainly within or involving the anterior and middle mediastinum, and one case confined to the anterior inferior mediastinum. Nine cases were round, one case was oval, one case was half round. Seven cases with fat ingredients displayed within the lesions, four cases with fat nodules within the cystic walls;ten cases showed as cysts with significant walls;MCI protrude type in six cases and smooth type in five cases. Fat, hair, keratosis, mucus and other ingredients were found in each cavity in surgery and pathology examination. Conclusion CT features of mediastinal cystic mature teratoma are complex and diverse, but with certain characteristics, thus CT is of great significance in the diagnosis and differential diagnosis of mediastinal cystic mature teratoma.