Role of Gd-DTPA Enhanced Fat-Suppression MR Imaging in Ovarian Tumors

PURPOSE: To determine the value of Gd-DTPA enhanced fat-suppression(GEFS) MR imaging in the characterization and differentiation of benign from malignant ovarian tumors. MATERIALS AND METHODS: MRI findings of thirty-seven patients with surgically proved 44 ovarian tumors (30 benign, 14 malignant) were studied retrospectively. MR imaging with conventional spin echo (CSE;Tl-weighted image TR/TE 450/20, T2-weighted image TR/TE 3500/30, 90) and GEFS were performed with a 1.5T GE signa. MRI findings of tumors including cystic or solid, wall and septal thickness, necrosis, invasion to adjacent organ, ascites and lymphadenopathy were assessed separately by using CSE and GEFS images, and then tumors were characterized as benign or malignant. RESULTS: Compared with CSE image, GEFS MR image showed better visualization of solid component in 5 malignant lesions, wall thickness in 5 malignant and 1 benign lesions, septal thickness in 3 malignant and 1 benign lesions, necrosis in 1 malignant lesion, and adjacent soft tissue invasion in 5 malignant lesions. Correct characterization of malignant tumors was increased from 71% on CSE image to 93% on GEFS image. However, correct characterization of benign tumors was 93% on both images. CONCLUSION: GEFS MR imaging could be useful for characterization of ovarian tumors, especially in malignant cases, and employed for differentiation of benign from malignant tumors.

Prognostic Significance of MR Angiography in Patients with Cerebral Infarction

PURPOSE: This study was designed to evaluate the prognostic significance of Magnetic resonance angiography(MRA) in patients with cerebral infarction. MATERIALS AND METHODS: Magnetic Resonance imaging(MRI) and 2 dimensional or 3 dimensional Time-of-Flight MR were performed subsequently in 83 patients with cerebral infarction proven by brain CT and clinical manifestations, using GE Signa Advantage 1.5T. We classified the size of infarction on MRI as Extent I((2cm), Extent 11(2-6cm), Extent ill( > 6cm) and classified the intracranial vascular occlusion according to visualizations of intracranial vascular branches on MRA as Grade 0, Grade I, Grade II, Grade III. And we evaluated clinical outcomes of these patients according to Rankin's disability scale, compared with MRI and MRA. RESULTS: In 72 cases(86.8%), the larger the size of infarction on MRI, the more severe vascular occlusion on MRA, the worse the clinical outcomes were noted(p < 0.01). However, in 7 cases(8.4%) who showed huge cerebral infarction on MRI with low grade intracranial vascular occlusion on MRA, the clinical outcomes were improved. In 4 cases(4.8%) who noted small sized cerebral infarction on MRI with high grade vascular occlusion on MRA, the clinical outcomes were worsened. CONCLUSION: MRA provides additional useful information to that provided by MRI in predicting the prognosis of patients with cerebral infarction.

3 Dimensional Volume MR Imaging of Intratemporal Facial Nerve

PURPOSE: To evaluate the usefulness of 3 dimensional-volume MR imaging technique for demonstrating the facial nerves and to describe MR findings in facial palsy patients and evaluate the significance of facial nerve enhancement. MATERIALS AND METHODS: We reviewed the MR images of facial nerves obtained with 3 Dimensional-volume imaging technique before and after intravenous administration of Gadopentetate dimeglumine in 13 cases who had facial paralysis and 33 cases who had no facial palsy. And we analyzed the detectabilty of anatomical segments of intratemporal facial nerves and facial nerve enhancement. RESULTS: When the 3 Dimensional-volume MR images of 46 nerves were analyzed subjectively, the nerve courses of 43(93%) of 46 nerves were effectively demonstrated on 3 Dimensional-volume MR images. Internal acoustic canal portions and geniculate ganglion of facial nerve were well visualized on axial images and tympanic and mastold segments were well depicted on oblique sagittal images. 10 of 13 patients(77%) were visibly enhanced along at least one segment of the facial nerve with swelling or thickening, and nerves of 8 of normal 33 cases(24%) were enhanced without thickening or swelling. CONCLUSION: MR findings of facial nerve paralysis is asymmetrical thickening of facial nerve with contrast enhancement. The 3 Dimensional-volume MR imaging technique should be a useful study for the evaluation of intratemporal facial nerve disease.

MR Imaging of Malignant Ovarian Tumors

PURPOSE: To evaluate MRI findings of malignant ovarian tumors. MATERIALS AND METHODS: MRI findings were retrospectively reviewed in 25 patients with surgically confirmed 30 malignant ovarian tumors(common epithelial tumor;23, sex cord stromal tumor;2, endodermal sinus tumor ; 1, metastatic tumor ;4). The findings evaluated were the lesion size, solid and/or cystic component, wall thickness, septal thickness, necrosis, invasion of adjacent organ, ascites, and adenopathy. RESULTS: MRI findings of the malignant ovarian tumors were as follow:Size of lesion was 5-35cm(mean 14cm) ;solid component was present in 80%(24/30);wall thickness was more than 3ram in 90%(27/30);septal thickness was more than 3ram in 70%(21/30);tumor necrosis was present in 40%(12/30%) ;invasion of adjacent organ was present in 76%(19/25);ascites was present in 56%(14/25);lymphadenopathy was present in 24% (6/25). MRI findings of absence of solid component(6/6), even wall and septal thickness(7/7, 19/19) were found only in epithelial tumors. Uneven septal thickness more than 3mm(7/11) was a predominant MRI findings of non-epithelial tumors. Well-defined cystic lesion within solid component was seen in Krukenberg tumors. CONCLUSION: Evaluation of the lesion size, internal architecture, invasion of adjacent organ, ascites, and lymphadenopathy in MRI would enable diagnosis of malignant ovarian tumors and could lead to possible differential diagnosis of epithelial tumors from non-epithelial tumors.

Usefulness of Magnetic Resonance Angiography in Intracranial Arteriovenous Malformation

PURPOSE: To evaluate clinical usefulness of magnetic resonance angiography(MRA) as a diagnostic modality and for treatment planning of intracranial arteriovenous malformations(AVM). METHODS AND MATERIALS: In 14 patients with intracranial AVM which were confirmed by operations, radiologic studies and clinical evaluations, magnetic resonance imaging(MRI), MRA and conventional angiography(CA) were retrospectively reviewed with specific regards to nidus depiction, detectability of feeding arteries and draining veins, and number and anatomic consistency of these vessles. MRA was obtained by 3 D TOF, 2 D PC, and 3 D methods with adequate VENC selection. RESULTS: Nidus of AVM was well demonstrated in MRI and MRA, and no remarkable difference in detection and size estimation of nidus among MRI, MRA and CA except 2 cases of associated intracranial hemorrhage, in which 3 D PC MRA well depicted nidus that were not visualized on MRI because of subacute hemorrhage. Feeding arteries were well demonstrated on 3 D TOF and 3 D PC MRA. Dilated draining veins were well depicted on 3 D PC MRA by scannig with adequate VENC selection, and the results were no remarkable difference compared with the ones on CA. CONCLUSION: MRA of a consecutive scan after MRI is a excellent modality for evaluation and treatment planning of intracranial AVM, and possible substitutive method for CA except for radiotherapy or transarterial embolization.

Usefulness of MR Angiography in Patients with Non-Traumatic Intracranial Hemorrhagic DiseasesI

PURPOSE: We assessed the usefulness of magnetic resonance angiography(MRA) and its techniques for differential diagnosis of hemorrhagic causes in patients with non-traumatic intracranial hemorrhagic disease. MATERIALS AND METHODS: We retrospectively reviewed 74 patients with non-traumatic intracranial hemorrhagic diseases, which were confirmed by radiological examinations(36 cases) and operations(38 cases). We compared the usefulness of magnetic resonance imaging(MRI) alone from MRI with MRA in evaluation of hemorrhagic causes. MRA was obtained by Time-of-Flight(TOF) and Phase Contrast(PC) technique. We investigated the usefulness of TOF and PC technique. RESULTS: MRI with MRA for detection of hemorrhagic causes(89%, 66 cases) was better than MRI only (64%, 47 cases). PC was better than TOF for evaluation of arteriovenous malformation and aneurysm due to subtraction of background noise(hemorrhage). CONCLUSION: MRI with MRA in more useful than MRI alone for evaluation of non-traumatic intracranial hemorrhagic causes.