No abstract available.
Mitral Valve*

PURPOSE: To evaluate the degree of contrast enhancement of intracranial tumors on delayed (6-8min.) MR imaging after administration of Gd-DTPA. MATERIALS AND METHODS: Both immediate and delayed post-contrast MR imagings were studied prospectively in 35 patients. with brain tumors (11 gliomas, 6 meningiomas, 4 neurinomas, 5 parencymal metastases, 5 hemangioblastoma, 4 others) at either 0.5 T or 2.0 T unit. After precontrast TI-, proton-density, and T2-weighted spin echo images were obtained, each patient underwent Tl-weighted imaging immediately following infusion of 0.1 mmol/Kg of Gd-DTPA. Subsequently, the second postcontrast Tl-weighted images were obtained with no additional injection of the contrast media. Time-interval between the postcontrast immediate and the delayed images was approximately 6-8 minutes. Degree of contrast enhancement of the lesions was assessed both visually and quantitatively. For quantitative study, contrast enhancement ratio(CER) of tumors was calculated in both immediate and delayed post-contrast images. RESULTS: There was stronger visual enhancement in 7 of 11 cases with gliomas and 3 of 5 cases with parenchymal metastasis on delayed images when compared with immediate images, whereas all 10 cases of extraaxial tumors(meningiomas and neurinomas) showed decreased enhancement on delayed images. Quantitatively, mean CERs of gliomas and metastases were higher on delayed study than on immediate study by 20. 5% and 49.2%, respectively. Extraaxial tumors showed decrease of CER on delayed study by 19.7% as compared with that of immediate study. Hemangioblastomas showed visually poor enhancement on delayed image in 4 cases and equal enhancement on both immediate and delayed images in remaining one case, and quantitatively demonstrated decrease of CER on delayed study by 15.4%. CONCLUSION: Since there was more conspicuous contrast enhancement in many intraaxial tumors such as gliomas and metastases on 6-8 minutes delayed post-contrast MR study, the delayed post-contrast study may be needed in some intraaxial tumors for their characterization, and may also be helpful for the differential diagnosis between intraaxial and extraaxial tumors.
Brain Neoplasms* ; Brain* ; Contrast Media ; Diagnosis, Differential ; Gadolinium DTPA ; Glioma ; Hemangioblastoma ; Humans ; Magnetic Resonance Imaging* ; Meningioma ; Neoplasm Metastasis ; Neurilemmoma ; Prospective Studies

PURPOSE: We retrospectively performed this study to evaluate the characteristic findings of maxillomandibular ameloblastomas on CT and MR imaging. MATERIAS AND METHODS: We reviewed histologically proved 12 cases of ameloblastomas, of which 7 cases were postoperative recurrent tumors. one of twelve cases was presumed ameloblastic carcinoma. Eleven cases were examined with CT and 3 cases with MR. RESULTS: The types were solid in 4, unicystic in 4, and mixed in the rest 4. CT and MRI of 11 ameloblastomas showed concentric expansile mass(n=11), cortical bone thinning and focal bone destruction by the tumors(n=9), well-margined, expansile destruction of surrounding sturctures(n=9), focal bulging of the tumors(n=6) and focal poorly-marginated invasion of tissue planes(n=4). Ameloblastic carcinoma showed ill defined irregular margin, aggressive invasion of surrounding structures and hematogeneous lung metastasis. Unerupted teeth or mural nodules were found in unicystic ameloblastomas. All three tumors examined by MRI showed isointensity to muscle on T1 weighted images and slight hyperintensity on T2 weighted images. The wall, septa and solid portions of the tumors were strongly enhanced on MR imaging. There was no difference in CT or MR finding between primary and recurrent tumors. CONCLUSION: Ameloblastomas showed solid, cystic or mixed pattern, and commonly well marginated expansile contour with local aggressiveness. Presence of mural nodules on CT in unicystic ameloblastoma with unerupted tooth was helpful in distinguishing ameloblastoma from dentigerous cyst.
Abdominal Pain ; Ameloblastoma* ; Ameloblasts ; Body Temperature ; Catheters ; Dentigerous Cyst ; Ethanol* ; Follow-Up Studies* ; Humans ; Kidney ; Liver ; Lung ; Magnetic Resonance Imaging* ; Neoplasm Metastasis ; Recurrence ; Retreatment ; Retrospective Studies ; Sleep Stages ; Tooth, Unerupted ; Ultrasonography

Gatric duplication is a rare congenital anomaly. Thus for about 90 cases of gastric duplication have been recorded in the literature. It is less frequent than small intestinal or eosphageal duplication, and accounts for only 3.8% of all gastrointestinal tract duplication. Most gastric duplications are seen during the first year of life. Palpable abdominal mass and gastric outlet obstruction in infancy are most common presentation. We experienced a case of non-communicating gastric duplication. A 12-year-old girl visited St. Mary's Hospital because of indigestion, intermittent vomiting, and left upper quandrant pain for about 40 days. She have had intemittent abdominal pain with concomitant increased level of amylase since 5 years old. Physical examination showed a hen's egg sized palpable mass on left upper quadrant of the abdomen. Upper GI series and barium enema revealed only indentation of duodenal C-loop, and sonogram and abdominal CT demonstrated isolated cystic mass along the greater curvature of gastric antrum. She had taken an operation under the impression of pancreatic pseudocyst. Operation revealed a cystic mass, located along the greater curvature. There was no pathologic change in the pancreas. Microscopic findings of the cyst wall revealed normal gastric mucosal lining and common muscle layer, shared with gastric antral muscle layer.
Cysts

We retrospectively analyzed the Magnetic Resonance (MR) imaging findings in 41 cases of histologically proved malignant tumors of oral cariey. The diagnostic value of MR imaging in detection and delineation of the lesions was assessed. The value of MRI was compared with that of Computed Tomography (CT) in 14 patients. Thirty-four cases of 41 malignant tumors were squamous cell carcinomas. Adenoic cystic carcinomas (2 cases), malignant melanomas (2 cases), non-Hodgkin lymphomas (2 cases) and mucoepidermoid carcinoma(1 cases) were also included in this study. Most of the lesions were isointense or slightly hyperintense to muscle on T1 weighted images and showed variable degrees of high signal intensity on T2 weighted images. Two cases of malignant melanomas showed characteristic hyperintensity on T1 weighted images. T2 weighted image was better in detection and delineation of tumor in most of the cases. In 6 cases, Gd-DTPA-enhanced T1 weighted image was better than T2 weighted image. T2 weighted image was useful for the evaluation of deep tissue infiltration and T1 weighted image was useful for the evaluation of bone invasion and superficial tissue plane invasion. The lesion was detected only by MR in 3 cases of 14 in which CT was also performed. MR imaging was more sensitive in the evalustion of bone marrow involvement. MR imaging is very useful modality in evaluating oral cavity malignany and is superior to CT in delineation of the as well as in the evaluation of mandible invasion.
Bone Marrow ; Carcinoma, Squamous Cell ; Humans ; Lymphoma, Non-Hodgkin ; Magnetic Resonance Imaging* ; Mandible ; Melanoma ; Mouth* ; Retrospective Studies

PURPOSE: The purpose of this study is to describe the anglographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of anglographic assessmant needed before embolization. MATERIALS AND METHODS: We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous realformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n=5), branches of external carotid artery (n=2) and common carotid artery (n=3). Common carotid artery or internal carotid artery (n=9), vertebral artery (n=5), ipsilateral external carotid artery (n=4), contralateral external carotid artery (n=5), costocervical trunk (n=2), thyrocervical trunk (n=2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. RESULTS: The collateral vascular channels were inferolateral trunk of internal carotid artery (n=8), vertebral artery (n=5), contralateral external carotid artery (n=5), ipsilateral external carotid artery (n=4), deep cervical artery (n=2) and ascending cervical artery (n=l). Embolizations were performed in 9 cases with operative cannulation(n=4), embolization via collateral branches of ipsilateral external carotid artery (n=l), embolization via collateral branches of contralateral external carotid artery (n=3) and balloon occulusion via direct puncture (n=l). CONCLUSION: The collateral channels in cervicofacial vascular lesions with previouly ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete anglographic assessment of possible collateral channels is mandatory for the effective and safe embolization.
Angiography ; Arteries ; Arteriovenous Malformations ; Carotid Arteries* ; Carotid Artery, Common ; Carotid Artery, External ; Carotid Artery, Internal ; Fistula ; Hemangioma ; Punctures ; Retrospective Studies ; Vertebral Artery

PURPOSE: Subacute necrotizing myelopathy(SNM) is a rare non-tumorous disease of spinal cord characterized by subacute clinical course of progressive neurological deterioration. We report MR findings of a patient with pathologically proved SNM. MATERIALS AND METHODS: 1 case of pathologically proved subacute necrotizing myelopathy. RESULTS: The patient was a 56-year-old man with progressive motor weakness and sensory loss of the lower extremities, and urinary and fecal incontinence for 11 months. Spine MRI revealed diffuse enlargement of the thoracic spinal cord from T2 to T7 level. Signal intensity of the expanded spinal cord was isointense relative to normal cord on T1 -weighted image and hyperintense on proton-density and T2-weighted images. On contrast enhanced T1-weighted image, there was diffuse homogeneous enhancement in the expanded cord lesion. CONCLUSION: MR demonstration of stable persistence of spinal cord lesion or atrophy over months or years with clinical findings of radual progressive neurologic deterioration may be helpful in the diagnosis of SN M(1 ).
Atrophy ; Diagnosis ; Fecal Incontinence ; Humans ; Lower Extremity ; Magnetic Resonance Imaging ; Middle Aged ; Spinal Cord ; Spinal Cord Diseases* ; Spine

PURPOSE: The purpose of this study is to correlate the MR findings with clinical stage and clinical outcome, and to describe the evolutional changes of abnormal MR findings of transverse myelitis. MATERIALS AND METHODS: Medical records and spinal MR images of 23 patients with both clinical and radiological diagnosis of transverse myelitis were retrospectively reviewed. MR findings were correlated with clinical stages including interval between MR imaging and full development of clinical symptoms, and compared with the clinical outcome. RESULTS: Diffuse high signal intensity of the spinal cord on T2-weighted image with mild cord bulging (67%) and focal contrast enhancement of the cord (75%) were observed within the first four weeks after full development of clinical symptoms. The findings decreased in extent or vanished later than four weeks on either initial or follow-up MR images. Most patients with either cord atrophy or focal hemorrhagewithin the cord lesion had poor clinical outcome. CONCLUSION: The MR findings of transverse myelitis are nonspecific, which may be seen in a variety of diseases. Serial MRIs, especially follow up examination over at least one month after full development of clinical symptoms are useful in the diagnosis of transverse myelitis and predicting its prognosis.
Atrophy ; Diagnosis ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Medical Records ; Myelitis, Transverse* ; Prognosis ; Retrospective Studies ; Spinal Cord

No abstract available.
Wernicke Encephalopathy*

OBJECTIVE: With the introduction of third-generation light-emitting diodes (LEDs) in dental practice, it is necessary to compare their bracket-bonding effects, safety, and efficacy with those of the second-generation units. METHODS: In this study, 80 extracted human premolars were randomly divided into eight groups of 10 samples each. Metal or polycrystalline ceramic brackets were bonded on the teeth using second- or third-generation LED light-curing units (LCUs), according to the manufacturers’ instructions. The shear bond strengths were measured using the universal testing machine, and the adhesive remnant index (ARI) was scored by assessing the residual resin on the surfaces of debonded teeth using a scanning electron microscope. In addition, curing times were also measured. RESULTS: The shear bond strengths in all experimental groups were higher than the acceptable clinical shear bond strengths, regardless of the curing unit used. In both LED LCU groups, all ceramic bracket groups showed significantly higher shear bond strengths than did the metal bracket groups except the plasma emulation group which showed no significant difference. When comparing units within the same bracket type, no differences in shear bond strength were observed between the second- and third-generation unit groups. Additionally, no significant differences were observed among the groups for the ARI. CONCLUSIONS: The bracket-bonding effects and ARIs of second- and third-generation LED LCUs showed few differences, and most were without statistical significance; however, the curing time was shorter for the second-generation unit.
Adhesives ; Bicuspid ; Ceramics ; Humans ; Plasma ; Tooth