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at about 70 degrees C. In nine of ten cases in Groups B and C, the hepatic capsule around the gallbladder fossa was retracted at about 80 degrees C. The mean thickness of liver parenchymal damage adjacent to the gallbladder was 5.4 mm in Group B and 9.8 mm in Group C. In Group A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.

Brain MRI Findings of the Olivopontocerebellar Atrophy

PURPOSE: To demonstrate the MRI findings of olivopontocerebellar atrophy. MATERIALS AND METHODS: We retrospectively reviewed the MRI findings of eight patients who had been diagnosed by clinical manifestation and the peculiar pattern of atrophy and signal change on MRI. RESULTS: Seven patients had an atrophy of the olive, pons and cerebellum and increased signal change of the transverse pontine fiber, median raphe and middle cerebellar peduncle on T2WI. Of these, six patients had severe atrophy of the olive, pons and cerebellum and decreased signal change of the basal ganglia, red nucleus, substantia nigra or dentate nucleus on T2WI. Additionally, four of six patients had a cerebral atrophy. Except one patient who had an urinary incontinence, these 5 patients had not been associated with extrapyramidal or autonomic symptom. The other patient with relatively short duration of the disease had only cerebellar atrophy without signal change on T2WI . CONCLUSION: With progressing of the olivopontocerebellar atrophy, cerebral atrophy and decreased signal change of the basal ganglia, red nucleus, substantia nigra or dentate nucleus on T2WI is combined. Thus, MRI is essential in establishing the diagnosis and evaluating the severity of olivopontocerebellar atrophy.

Systemic Lupus Erythematosus: Abdominal Radiologic Findings

Systemic lupus erythematosus(SLE) is a systemic disease of unknown etiology. Its main pathology is vasculitis and serositis, due to deposition of the immune complex or antibodies. Most findings are nonspecific ; abdominal manifestations include enteritis, hepatomegaly, pancreatic enlargement, serositis, lymphadenopathy, splenomegaly,nephritis, interstitial cystitis, and thrombophlebitis. We described radiologic findings of various organinvolvement of SLE; digestive system, serosa, reticuloendothelial system, urinary system, and venous system.Diagnosis of SLE was done according to the criteria of American Rheumatism Association. Understanding of thevariable imaging findings in SLE may be helpful for the early detection of abdominal involvement andcomplications.

Subacromial Bursitis with Rice Bodies: A Case Report

Multiple rice bodies in joints or bursae are rarely encountered in patients with rheumatoid arthritis. Wereport the radiologic findings of massive subacromial bursitis with innumerable rice bodies on the right shoulderof a 38-year-old man with rheumatoid arthritis. Subacromial bursography showed markedly distended bursa withmultiple nodular filling defects. Preconstrast CT scanning revealed well-demarcated hypodense lesion withoutcalcification in subacromio-subdeltoid bursa. Multiple rice bodies showed slightly high signal intensity on T1WIand T2WI, and no enhancement after gadolinium injection.

CT Angiography in the Diagnosis of Cerebral Aneurysm: Comparison of MIP and SSD Techniques

PURPOSE: To evaluate the usefulness of CT angiography and to compare SSD(Shaded Surface Display) andMIP(Maximum Intensity Projection) in the diagnosis and preoperative evaluation of the cerebral aneurysms. MATERIALS AND METHODS: Twenty-six aneurysms in 20 patients were diagnosed on conventional angiography and surgerywas performed. For preoperative evaluation, all patients underwent CT angiography, with spiral CT for preoperativeevaluation. Using SSD and MIP techniques, the results were proccessed and compared; three radiologistsretrospectively analysed detectability, size, neck visualization, delineation of shape, direction, therelationship with surrounding vessels-including the feeding artery of the aneurysm-and intraluminal thrombicontaining calcification. RESULTS: Twenty five of 26 aneurysms (96.2%) were detected by CT angiography, while MIPand SSD depicted 25 (96.2%) and 24 (92.3%), respectively. The largest diameter of the aneurysms was 11-15mm infour cases, 6-10mm in ten, and 3-5mm in 12 (mean 7.38mm, SD=3.34). With regard to detectability, MIP led to onefalse negative result, and SSD to two false negative and one false-positive results. Aneurysm neck assessment byMIP was clear in 96.0% of cases (24/25), and by SSD in 83.3% (20/24). For the depiction of directions and feedingvessels of the aneurysms, and intraluminal thrombi containing calcification, MIP was superior to SSD, while fordepicting shape and the relationship with surrounding structures, SSD was superior to MIP. CONCLUSION: For theassessment of cerebral aneurysms, MIP is somewhat superior to SSD. The characteristics of aneurysms and theirrelationship with surrounding structures can, however, be better evaluated by combining the two techniques.

Normal Anatomical Variation of the Intrahepatic Portal Vein in Korean

PURPOSE: To determine the prevalence of variations in the intrahepatic portions of portal veins, as visualized by arterial portograms, and to examine the surgical implications of these findings in Koreans. MATERIALS AND METHODS: Five hundred and nineteen arterial portograms of 519 patients with no evidence of vascular tumor invasion or distortion were retrospectively reviewed. In all patients, the main, right, right anterior, right posterior and left portal vein were visualized. RESULTS: Variations in intrahepatic portal anatomy were found in 102 patients (19.6%) and involved an immediate trifurcation of the main portal vein in 82 (15.8%) a right posterior segment from the main portal vein in ten (1.9%), a right anterior segment from the left portal vein in nine (1.7%) and an absent horizontal portion from the left portal vein in one (0.2%). CONCLUSION: On arterial portogram, variations in the intrahepatic portions of the portal veins are frequently seen. The recognition of such variations is important in the preoperative evaluation of patients with hepatic tumors, since the variations may have implications for tumor resection, for the localization of tumor thrombi and in interventional radiologic procedures involving the portal vein.

Hemoptysis: Comparison of High-resolution CT with Fiberoptic Bronchoscopy

PURPOSE: To compare the precise roles of high-resolution computed tomography (HRCT) and fiberoptic bronchoscopy (FOB) in the evaluation of patients presenting with hemoptysis and to determine the optimal timing for HRCT. MATERIALS AND METHODS: The results of HRCT and FOB were compared in 23 patients (15 men, 8 women) presenting with hemoptysis. Etiologies included bronchietasis (n=4), parenchymal pulmonary tuberculosis (n=4), lung cancer (n=4), endobronchial tuberculosis (n=2), and broncholithiasis (n=2). Hemoptysis was proved to be due to miscellaneous causes in an additional three cases and to be cryptogenic in four. The diagnostic results of FOB performed before and after HRCT were compared as were those of HRCT performed within and after the first 48 hours of active bleeding. RESULTS: FOB and HRCT offered a correct diagnosis in 39% and 65% of cases, respectively (p=0.005). HRCT demonstrated three cases of bronchiectasis and three of parenchymal pulmonary tuberculosis which were beyond the range of a bronchoscope. In two of five cases in which HRCT findings were nonspecific, chondromatous hamartoma and lung cancer were confirmed by FOB. In cases where HRCT was performed prior to FOB, the latter demonstrated the location and diagnosis in 82% and 47% of cases, respectively (p=0.303) ; when HRCT was performed after FOB, HRCT was correct in 67% and 17% of cases, respectively (p=0.178). In none of three cases (0%) in which HRCT was performed during the first 48 hours of active bleeding did the procedure allow a specific diagnosis. In 15 of 20 (75%) cases in which HRCT was performed after the first 48 hours, however, the diagnosis provided by CT was correct. CONCLUSION: The results of this study suggest that in patients presenting with hemoptysis, both HRCT and FOB should be used for evaluation, since they are diagnostically complementary. FOB is more useful for the diagnosis of endobronchial lesion, and HRCT for bronchiectasis and parenchymal pulmonary tuberculosis. If, in cases of hemoptysis, initial diagnosis is attempted within the first 48 hours of active bleeding, FOB should be the initial step, and HRCT images should not be obtained until active bleeding has been shown on plain chest radiograph to have abated. If this initial approach takes place after the first 48 hours of active bleeding, FOB and HRCT are equally suitable.

Multiple Bone Metastasis of Medulloblastoma: A Case Report

Medulloblastoma is one of the most undifferentiated primitive neuroectodermal tumors and represents about 30% of all posterior fossa tumors in children. Disseminated medulloblastoma, mainly involving cerebral surfaces, ventricles and the subarachnoid space can, in 50% of patients, be identified on intial imaging studies. One thirdof these lesions metastasize to an extracranial site, primarily to bone. Osseous metastases, which occur mainly after craniectomy are typically lytic, but osteoblastic lesions also may occur. We experienced the case of a 14year-old female patient with multiple bone metastases of medulloblastoma after craniectomy. Bone metastaticlesions were present in the right femur and thoracic spine and were osteoblastic or osteolytic