The Value of CT in detecting Pathologic Bowel Perforation

PURPOSE: To evaluate the usefulness of CT for assessing the location and cause of pathologic gastrointestinal perforation. MATERIALS AND METHODS: A retrospective analysis of abdominal CT was performed in 27 perforations of 26 patients with underlying gastrointestinal pathology. Fifteen benign and 12 malignant perforations consisted of five gastric cancers, one gastric ulcer, ten duodenal bulb ulcers, two bowel adhesions, one jejunal metastasis from lung cancer, one ileocolic Crohn's disease, one radiation colitis and six colon cancers. CT scans were evaluated for 1) diagnosis of bowel perforation, 2) assessment of the cause and site of perforation, and, in particular, differentiation between benignancy and malignancy, and 3) complications and their extent. RESULTS: CT easily detected varying amounts of free air or fluid collection, and infiltration or abscess formation adjacent to the main lesion, and the diagnosis of gastrointestinal perforation was therefore easy. In 11 of the 12 malignancies (92%), primary tumor was diagnosed, but detection of the site of perforation was possible in only seven cases (7/12, 58%). The 15 benign lesions revealed nonspecific CT findings, and the perforation site could be presumed in six (6/15, 40%). In one case of Crohn's disease, the primary cause was visualized. Among six colonic cancers, four pericolic abscesses and two fistulas to adjacent organs were found, but there was no evidence of diffuse peritonitis. CONCLUSION: CT was helpful to lead to optimal treatment of pathologic gastrointestinal On CT, the detectability of perforation, primary benign or malignant lesion, perforation site and extent of complication was high, and this modality was therefore a useful indicator of the optimal treatment for pathologic gastrointestinal perforations.

Experimental Study on the Rim-Enhancing Lesion of Rabbit Brain Abscess: MR Imaging and Histopathologic Correlation

PURPOSE: To evaluate on the basis of histopathologic carrelation the MR findings of mature brain abscess inthe rabbit, with particular attention to rim-enhancing lesions. MATERIALS AND METHODS: The evolution of abscess formation was obtained by the direct inoculation of Staphylococcus aureus into the gray-white matter junctions ofthe brains of 16 rabbits. The stages of brain abscesses were divided into four : early cerebritis (days 1 to 5after inoculation of the organism) ; late cerebritis (days 6 to 14) ; early capsular (days 16 to 21) ; and latecapsular (days 22 to 28). The available MR images showed 14 cases at the stage of early cerebritis, seven at thelate cerebritis stage, three at the early capsular, and one at the late capsular stage. According to the known pathology of brain abscesses and on the basis of both MR imaging and histopathologic findings, the lesions weregrouped according to whether they were found in the central necrotic, border, or peripheral zone. We analyzed the patterns of rim-enhancement (completeness of the rim, thickness, and margin) and the signal intensities of theabscess walls on MR images at each stage. Histopathologic correlation was performed in one case of each stage. We evaluated the presence or absence and degree of infiltration by inflammatory granulation tissue, microhemorrhage, reticulin, collagen, and hemosiderin of the abscess walls. RESULTS: Rim-enhancing lesions were present in threeof 14 cases at the late cerebritis stage, in all three cases at the early capsular, in one at the late capsular, but in none at the early cerebritis stage. The enhancing pattern of the late cerebritis stage was irregular-margined incomplete rim-enhancement, with irregular thickness of the abscess walls (3/3). The enhancing pattern of the capsular stages was well-defined, complete rim-enhancement with uniform thickness of the abscess walls (3/4). The signal intensities of the abscess walls at the late cerebritis and early capsular stages were variable. The late capsular stage was characterized by hypointensity of the abscess wall on both T1- and T2-weighted images. Histopathologically, the capsular stages were distinguished from the late cerebritis stage bythe marked infiltration of reticulin and the presence of collagen in the abscess walls. The most conspicuous pathologic finding distinguishing the late from the early capsular stage was abundant infiltration of the abscess wall by collagen and hemosiderin. CONCLUSION: The enhancing pattern of a brain abscess with mature capsule formation was characterized by a well-defined, complete rim-enhancing abscess wall of uniform thickness. The mature abscess wall was hypointense on both T1- and T2-weighted images, may be explained by marked infiltration bymature collagen and hemosiderin.

Pelvic Actinomycosis

PURPOSE: To demonstrate the radiologic characteristics of the pelvic actinomycosis. MATERIALS AND METHODS: We retrospectively reviewed the radiologic findings of seven patients with pathologically proven pelvic actinomycosis and analyzed the anatomical location, characteristics of the lesion and alteration of surrounding structures. RESULTS: The location of the lesions were the ovary and adnexa(n=4), rectum(n=1), cecum and terminalileum(n=1), and bladder(n=1). Three of the seven patients had a past history of intrauterine devices.Post-contrast enhanced CT showed an ill-defined mass with inhomogeneous enhancement and a tendency to invade th esurrounding normal tissue plane. CONCLUSION: Pelvic actinomycosis should be included in differential diagnosis when an unusually aggressive infiltrative mass is located in the pelvic cavity, especially in a patient with long-term use of intrauterine contraceptive devices.

CT and MR Findings of Intracranial Ganglioglioma

PURPOSE: The purpose of this study was to evaluate clinical, CT and MRI findings of intracranial ganglioglioma. MATERIALS AND METHODS: All patient were between 9 and 30 years old, and were men. Four patients with pathologically proved gangliogliomas were included in this study. CT and MR images were assessed retrospectively for location, type, density, signal intensity and contrast enhancement pattern of tumors. RESULTS: All patients suffered from epileptic seizure of long history. The tumors were located in temporal lobe(3 cases) and frontal lobe(1 case). The type of tumor were solid (2 cases) and cystic(2 cases). On the CT scan, the cystic lesions were hypodense and the solid lesions were isodense to normal brain parenchyme. Calcification within lesion was noted in 3 cases. On the MR imaging, cystic lesions reveal high signal intensity on T2-weighted image(T2WI) and low signal intensity on Tl-weighted image(T1WI). One of the solid lesions showed iso-signal intensity on T1WI and high signal intensity on T2WI. Another revealed high signal intensity on both T1WI and T2WI. The signal intensity of the calcifications(3 case) was variable. Two cases showed signal void, one case revealed high signal intensity on T1WI and low signal intensity on T2WI. In three patients, the lesions enhanced after intravenous administration of Gd-DTPA. CONCLUSION: Ganglioglioma should be considered in the differential diagnosis when the children or young male with epilepy have a cystic mass with calcification or ill- defined solid mass, especially in temporal lobe on CT or MRI.

CT and MR Findings of Intracranial Ganglioglioma

PURPOSE: The purpose of this study was to evaluate clinical, CT and MRI findings of intracranial ganglioglioma. MATERIALS AND METHODS: All patient were between 9 and 30 years old, and were men. Four patients with pathologically proved gangliogliomas were included in this study. CT and MR images were assessed retrospectively for location, type, density, signal intensity and contrast enhancement pattern of tumors. RESULTS: All patients suffered from epileptic seizure of long history. The tumors were located in temporal lobe(3 cases) and frontal lobe(1 case). The type of tumor were solid (2 cases) and cystic(2 cases). On the CT scan, the cystic lesions were hypodense and the solid lesions were isodense to normal brain parenchyme. Calcification within lesion was noted in 3 cases. On the MR imaging, cystic lesions reveal high signal intensity on T2-weighted image(T2WI) and low signal intensity on Tl-weighted image(T1WI). One of the solid lesions showed iso-signal intensity on T1WI and high signal intensity on T2WI. Another revealed high signal intensity on both T1WI and T2WI. The signal intensity of the calcifications(3 case) was variable. Two cases showed signal void, one case revealed high signal intensity on T1WI and low signal intensity on T2WI. In three patients, the lesions enhanced after intravenous administration of Gd-DTPA. CONCLUSION: Ganglioglioma should be considered in the differential diagnosis when the children or young male with epilepy have a cystic mass with calcification or ill- defined solid mass, especially in temporal lobe on CT or MRI.

MR measurements of corpus callosum in normal adults

To evaluate criterial for detecting corpus callosum (CC) abnormality, measurements of CC were done in 100 Korean adults on midline sagittal T1 weighted images using the spin echo technique with a 2.0 Tesla MR unit. The mean (±SD) anteroposterior diameter of CC, and the mean (±SD) thicknesses of genu, body, transition, and splenium were 71.1±5.0, 11.2±1.6, 5.7±1.0, 3.6±10, and 11.6±1.6mm, respectively. The outlines of CC were traced directly from the scans, and the maximal anteroposterior length of the CC was divided into quartiles. Area measurements of the anterior quartile, body, splenium, and whole CC were made with a digitizer pad and computer, and the mean (±SD) areas of these were 211±36, 194±36, 205±34, and 610±90mm, respectively. The following ratios were calculated; Maximum anteroposterior diameter of CC/length of brain, area of anterior quartile/area of whole CC, area of body/area of whole CC, and area of splenium/area of whole CC. There was a statistically significant increased of maximum anteroposterior diameter of CC/length of brain by age, and a statistically significant decrease of the area of the body by age. However, there were no statistically significant differences of all measurements between males and females.

MR imaging of avascular necrosis of the femoral head: correlation with radiograph, radionuclide scan and clinical finding

To explore the ability of magnetic resonance imaging(MRI) in the diagnosis of avascular necrosis(AVN) of the femoral head, we compared appearances on MRI of 85 proven AVN lesions with those on radiographs(n=79)and radionuclide scans(n=75). Clinical symptoms(n=85) were also correlated. All MR studies included coronal and axial T1WI and coronal T2WI. All lesions involved the anterosuperior aspect of the femoral head and were surrounded by a low signal intensity rim of both T1 and T2WI. The signal intensity of the lesions was variable depending on the disease course, and lesions were divided into four classes according to the classification suggested by Mitchell. Radiogrphs were normal in 16%(13/79) of the lesions which were in MR class A(10), B(1), C(2). The radionuclide scans showed normal in 16%(12/75) of the lesions which were in MR class A(8), B(1), C(2), D(1). On the other hand. 93% of the lesions with MR class A(27/29) showed stage 1 and 2 lesions on radiographs. Clinical symptoms were absent in 25%(21/85) of the leions, and among these. 81%(17/21) were MR class A. Conclusively. MR is superior to the radiograph and radionuclide scan in the early detection of AVN, and can also show the exact location, extent and signal chasacteristics of the lesion. Therefore, MR is essential in diagnosis and management of AVN.

MR findings of craniopharyngioma

Craniopharyngioma is a benign, slow-growing tumor that constitues 3-9% of all intracranial tumors, and arises from epithelial remnants of the Rathke's pouch. We analized MR (2.0T) findings of ten cases with surgically proved craniopharyngioma retrospectively. CT was avilable in five cases, and Gd-DTPA was used in six cases. Characteristic findings of craniopharyngioma in MRI included multilocularity and variable signal intensities within each loculus that were more prominent in T1WI. Detection rate of calcification in MR was 60%. Six cases with Gd-DTPA enhancement revealed irregular or rim-like enhancement. MRI provides useful informations regarding the location, extent and biochemical characteristics of the oraniopharyngioma as well as its relationship to the neighboring structures which will be valuable in planning surgical resection.

Measurement of mesencephalic tectum by magnetic resonance imaging in adults

No abstract available.

ERCP findings of extrahepatic bile duct carcinoma

In the diagnosis of bile duct carcinoma, oral or intravenous cholangiography is of no air in the majority ofpatients with bile duct carcinoma who are jaundiced. Recently ultrasonography and CT are widely used for evalutionof biliary disease, but direct visualizing methods of the biliary tract by ERCP and PTC gives more detailed information and exact localization of the lesion. ERCP is less invasive and dangerous and has some more advantages than PTC. We analyzed 33 cases of confirmed extrahepatic bile duct caracinoma who were performed ERCP. The resultswere as follows; 1. The 7th decade was the predilection age, and the radio of male to female was 3.:1. 2. Thelocations of extrahepatic bile duct carcinomas were common bile duct in 45.5%, common hepatic duct in 27.3%,junction of cystic duct and widely extended in 12.1% respectively and junction of hepatic duct in 3.05 in order offrequency. 3. ERCP finding of extrahepatic bile duct carcinomas revealed complete obstruction of bile duct in mostcases, and irregular margined protuberant type was more common than smooth margined constricted type atobstruction site. 4. ERCP finding according to the location of lesion showed that protuberant type was relativelyfrequent in common bile duct and constircted type in common hepatic duct respectively.

Computed tomography of late-onset epilepsy

Epilepsy can be divided into idiopathic epilepsy and symptomatic epilepsy according to the existence ofunderlying organic disease. It has been said that the incidence of the symptomatic epilepsy caused by underlyingorgainic brain disease is higher in late-onset epilepsy after the age of 20 than in childhood-onset epoilepsy. CTis very sensitive and non-invasive method for detection of organic brain disease. 168 cases of late-onset epilepsyafter the age of 20 were studied by CT in recent 2 years were analyzed. The results were as follows; 1. The 3rddecade was the most frequent age group, and the ratio of male to female was 2.5;1. 2. Structural abnormality onbrain CT was demonstrated in 51.8% of hte patient. 3. The older the onset of age was, the higher the rate of theabnormal CT finding, except 5th decade which showed less CT abnormality than 4th decade. 4. The most frequenthistory related to epilepsy was trauma. 63.1% of the patients had no relevant history; and they showed CT findingsof brain tumor, atrophy and infarction in decreasing order of frequency. 5. Abnormal CT finding was demonstratedin 49.2% of normal neurologic examination and in 46.4% of normal EEG study. 6. The most frequent lesion ofabnormal CT scan in late-onset epilepsy was 30 cases(18.4% )of brain atrophy. The next frequent lesion was 18cases (10.7%) of brain tumor. Infarction, parasites and calcification were other frequnet lesions.