Parietal Intraparenchymal Schwannoma: Case Report

We report a case of an intraparenchymal schwannoma of the left parietal lobe. A 51-year-old woman was admitted to our hospital with complaints of intermittent headaches. Computed tomography and magnetic resonance images revealed a 1.3 cm sized intra-axial homogeneous enhancing mass in the left parietal lobe. The lesion was pathologically confirmed to be a schwannoma.

The Usefulness of Diffusion-tensor MR Imaging (DTI) in the Grading of Gliomas

PURPOSE: The purpose of this study was to evaluate the usefulness of diffusion tensor imaging (DTI) in the grading of gliomas. MATERIALS AND METHODS: DTI was performed in 24 patients with histologically confirmed brain gliomas. After placing the regions of interest (ROI) in the tumor center, tumor border, white matter adjacent to tumor, and normal-appearing white matter (NAWM) of the contralateral hemisphere, the FA values were measured. The size of the ROI was found to be 61 ml. In addition, the FA ratios were calculated for the ROIs in relation to the NAWM of the contralateral hemisphere. RESULTS: The mean FA ratios in patients with grade II gliomas were 0.348 for the tumor center, 0.564 for the tumor border, and 0.897 for the white matter adjacent to the tumor. For patients with grade III gliomas, the mean FA values were 0.247, 0.346, 0.782, respectively. Further, for patients with grade IV gliomas, the mean FA values were 0.204, 0.226, 0.336, respectively. The differences in the FA ratios between the grade II and III tumors were significant in the tumor center and tumor border (p = 0.005, p = 0.002, respectively). Moreover, the differences in the FA ratios between the grade III and IV tumors were significant in the tumor border and white matter adjacent to the tumor (p = 0.004, p = 0.004, respectively). CONCLUSION: DTI is a non-invasive imaging modality that may provide valuable information for the pre-operative grading of gliomas.

Tracking of Neural Stem Cells in Rats with Intracerebral Hemorrhage by the Use of 3T MRI

OBJECTIVE: To access the feasibility of clinically available 3T MRI to detect the migration of labeled neural stem cells (NSCs) in intracerebral hemorrhage (ICH) in a rat model. MATERIALS AND METHODS: The ethics committee of our institution approved this study. ICH was induced by the injection of collagenase type IV into the right striatum of ten Sprague-Dawley rats. Human NSCs conjugated with Feridex (super-paramagnetic iron oxide: SPIO) were transplanted into the left striatum one week after ICH induction. MRI was performed on a 3T scanner during the first, second, third, fourth, and sixth weeks post-transplantation. MRI was obtained using coronal T2- and T2*-weighted sequences. Two rats were sacrificed every week after in vivo MRI in order to analyze the histological findings. RESULTS: ICH in the right striatum was detected by MRI one and two weeks after transplantation without migration of the NSCs. There was no migration of the NSCs as seen on the histological findings one week after transplantation. The histological findings two weeks after transplantation showed a small number of NSCs along the corpus callosum. On MRI three weeks after transplantation, there was a hypointense line along the corpus callosum and decreased signal intensity in the right periventricular region. Histological findings three weeks after transplantation confirmed the presence of the hypointense line representing SPIO-labeled NSCs. MRI four and six weeks after transplantation showed a hypointense spot in the right periventricular region. The histological findings four and six weeks after transplantation showed the presence of prominent NSCs in the right periventricular region. CONCLUSION: 3T MRI can detect the migration of NSCs in rats with ICH along the corpus callosum. Therefore, 3T MRI could be feasible for detecting the migration of NSCs in the clinical setting of stem cell therapy.

The Sentinel Clot Sign: a Useful CT Finding for the Evaluation of Intraperitoneal Bladder Rupture Following Blunt Trauma

OBJECTIVE: To evaluate the frequency and relevance of the "sentinel clot" sign on CT for patients with traumatic intraperitoneal bladder rupture in a retrospective study. MATERIALS AND METHODS: During a recent 42-month period, 74 consecutive trauma patients (45 men, 29 women; age range, 12-84 years; mean age, 50.8 years) with gross hematuria were examined by the use of intravenous contrast-enhanced CT of the abdomen and pelvis, followed by retrograde cystography. Contrast-enhanced CT scanning was performed by using a helical CT scanner. CT images were retrospectively reviewed in consensus by two radiologists. The CT findings including the sentinel clot sign, pelvic fracture, traumatic injury to other abdominal viscera, and the degree of intraperitoneal free fluid were assessed and statistically analyzed using the two-tailed x2 test. RESULTS: Twenty of the 74 patients had intraperitoneal bladder rupture. The sentinel clot sign was seen for 16 patients (80%) with intraperitoneal bladder rupture and for four patients (7%) without intraperitoneal bladder rupture (p < 0.001). Pelvic fracture was noted in five patients (25%) with intraperitoneal bladder rupture and in 39 patients (72%) without intraperitoneal bladder rupture (p < 0.001). Intraperitoneal free fluid was found in all patients (100%) with intraperitoneal bladder rupture, irrespective of an associated intraabdominal visceral injury, whereas 19 (35%) of the 54 patients without intraperitoneal bladder rupture had intraperitoneal free fluid (p < 0.001). CONCLUSION: Detection and localization of the sentinel clot sign abutting on the bladder dome may improve the accuracy of CT in the diagnosis of traumatic intraperitoneal bladder rupture, especially when the patients present with gross hematuria.

Efficacy of US-guided Hydrostatic Reduction in Children with Intussusception

PURPOSE: To assess the success rate and efficacy of US-guided hydrostatic reduction in children with intussusception. MATERIALS and METHODS: We retrospectively evaluated the ultrasonographic findings and clinical features of 121 children (M:F=80:41, mean age= 18 months) who underwent US-guided hydrostatic reduction between November, 2002 and February, 2007 for the diagnosis and treatment of intussusception. RESULTS: The 121 patients underwent 147 procedures, including recurred cases. Successful reduction was achieved in 132 cases (89.8% success rate), as confirmed by post-procedure ultrasonography and clinical findings. Emergency operations were performed in the 10 (6.8%) cases of irreducible intussusceptions, 8 of ileocolic type and 2 of ileoileal type. Perforation occurred in 4 cases (2.7%), and seizure in 1 case during the procedure (0.7%). CONCLUSION: US-guided hydrostatic reduction is a safe and effective tool for the diagnosis and treatment of pediatric intussusception.

Efficacy and Complications of Ultrasound-Guided Percutaneous Renal Biopsy Using Automatic Biopsy Gun in Pediatric Diffuse Renal Disease: Analysis of 97 Cases

PURPOSE: To evaluate the diagnostic efficacy and complications of ultrasound-guided percutaneous renal biopsy using automatic biopsy gun in patients with pediatric diffuse renal disease. MATERIALS and METHODS: Using an 18G automatic biopsy gun, biopsies were performed on 97 pediatric patients with clinically suspicious diffuse renal disease. The acquired tissue specimens were analyzed by photomicroscopy, immunofluorescence, and electron microscopy to support the diagnosis. In the 97 biopsies, the success of the histologic diagnosis, number of glomeruli, and complication rates were retrospectively evaluated by analyzing the variable exams and clinical records. RESULTS: Adequate tissue for histologic diagnosis was obtained in 91 of 97 biopsies (94%) and the mean number of glomeruli was 9.6. Complications such as minute pain, gross hematuria, and small perirenal hematoma presented in 22 of the 97 biopsies (23%), all of which either improved within 5-72 hours or did not need specific treatment. CONCLUSION: Ultrasound-guided percutaneous renal biopsy using 18G automatic biopsy gun is an effective and safe method for the histologic diagnosis of pediatric diffuse renal disease without any major complication.

Solitary Small Hepatic Angiosarcoma: Initial and Follow-up Imaging Findings

We report an uncommon case of solitary, small hepatic angiosarcoma that was initially considered as a hemangioma. We present the imaging findings, with an emphasis on the initial and follow-up CT and MR findings, as well as report on the more suggestive findings of angiosarcoma than those of a hemangioma.

CNS Involvement in Hemophagocytic Lymphohistiocytosis: CT and MR Findings

Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder that is characterized by proliferation of benign histiocytes, and this commonly involves the liver, spleen, lymph nodes, bone marrow and central nervous system (CNS). We report here on the CT and MR imaging findings in a case of CNS HLH that showed multiple ring enhancing masses mimicking abscess or another mass on the CT and MR imaging.

The Usefulness of 3T-TOF MR angiography in Patients with Cerebral Infarction

PURPOSE: This study was designed to evaluate the usefulness of 3T-TOF MR angiography (3T-TOF MRA) compared with transcranial Doppler sonography (TCD) and conventional angiography (CA) in patients with suspected cerebral infarction. MATERIALS AND METHODS: Fifty four patients with clinical symptoms of cerebral infarction were involved in this study, and had undergone 3T-TOF MRA and TCD, with CA in 11 patients. On the basis of divisions of the carotid artery, four groups were designated: group I, both vertebral arteries and basilar artery; group II, segment between 2 cm below bifurcation of common carotid artery and genu portion of internal carotid artery; group III, segment between petrous portion of internal carotid artery and bifurcation of anterior and middle cerebral artery; group IV, from bifurcation of anterior and middle cerebral artery to thier distal branches. Two radiologists retrospectively reviewed the vascular imaging and stenosis in 3T-TOF MRA, TCD, and CA. RESULTS: A total of 432 arteries, 108 in each group, were available. The assessment of vascular imaging quality in 3T-TOF MRA is scored 2.98, 2.96, 2.91, 2.88 in 4 groups, respectively. Agreement among 3TTOF MR angiography, TCD, and CA was high. CONCLUSION: 3T-TOF MR angiography may be useful method for the assessment of stenotic lesions of cranial vasculature in patients with cerebral infarction.

Five Cases of Neonatal Hepatic Hemangioendothelioma

Neonatal Hemangioendothelioma (HE) is the most common type of hepatic vascular tumor that presents in infancy. HE generally undergo spontaneous regression within a year, but it may become symptomatic and be associated with life-threatening complications including congestive heart failure, consumptive coagulopathy and hepatic rupture. We report five cases of neonatal hepatic HE with brief review of the literatures. The report include a case of HE associated with AV malformation complicated by congestive heart failure who was successfully treated by hepatic artery embolization, a case of HE associated with transposition of great artery (TGA), and three cases of asymptomatic HE with spontaneous involution.

Diagnostic Usefulness of Perilesional Edema around Intracerebral Hemorrhage in Predicting Underlying Causes

PURPOSE: We attempted to evaluate the diagnostic usefulness of the degree of perilesional edema around intracerebral hematoma in predicting the underlying cause. MATERIALS AND METHODS: This study included 54 patients with intracerebral hematoma for whom the underlying cause was confirmed by biopsy, radiological or clinical methods. Cases of subarachnoid hemorrhage, hemorrhagic transformation of cerebral infarction and intraventricular hemorrhage were excluded. The lesion size was defined as the average value of the longest axis and the axis perpendicular to this. The size of the perilesional edema was defined as the longest width of the edema. In all cases, the sizes of the lesion and edema were measured on the T2 weighted image. We defined the edema ratio as the edema size divided by the lesion size. RESULTS:23 cases were diagnosed as intracerebral hemorrhage due to neoplastic conditions, such as metastasis (n=17), glioblastoma (n=5), hemangioblastoma(n=1). 31 cases were caused by non-neoplastic conditions, such as spontaneous hypertensive hemorrhage (n=23), arteriovenous malformation (n=4), cavernous angioma (n=3), and moya-moya disease (n=1). In fourteen cases, which were confirmed as malignant intracerebral hemorrhage, the edema ratio was more than 100%. Of the other cases, only 8 were confirmed as malignant intracerebral hemorrhage. It was found that the larger the edema ratio, the more malignant the intracerebral hemorrhage, and this result was statistically significant (p<0.001). CONCLUSION: Measurement of perilesional edema and the intracerebral hematoma ratio may be useful in predicting the underlying causes.

MR Imaging Findings of Clonorchiasis

OBJECTIVE: The purpose of this study was to evaluate the MR spectrum and MR cholangiographic imaging findings of clonorchiasis. MATERIALS AND METHODS: We reviewed 26 patients with confirmed clonorchiasis by either stool tests (n=24) or surgery (n=2). MR imaging was performed on a 1.5 T system (GE Medical Systems, Milwaukee, WI) with a torso coil. Axial T1-and T2-weighted, gadolinium-enhanced dynamic images and MR cholangiography were obtained. Image analyses were used to identify abnormalities of the intrahepatic and extrahepatic bile ducts and the presence of hepatobiliary malignancy. All MR examinations were reviewed by the consensus of two abdominal radiologists. RESULT: Intrahepatic bile duct abnormalities were seen in 23 (89%) of the 26 patients. The most common finding was mild dilatation of the intrahepatic bile duct which was found in 21 (81%). "Too many intrahepatic ducts" were found in 16 (62%), wall enhancement and thickening in 21 (81%) and filling defects and ductal stricture in the intrahepatic bile duct in 6 (24%) and 3 (12%) patients, respectively. Extrahepatic ductal dilation was found in 5 (19%) and 9 (35%) revealed hepatobiliary malignancy. CONCLUSION: MR imaging revealed various findings of clonorchiasis, including dilatation, wall enhancement, stricture of the intrahepatic ducts and filling defect within the intrahepatic bile duct.

Three-Dimensional Computed Tomographic Angiography with Volume Rendering Technique in the Evaluation of Intracranial Aneurysms: Comparison with Three-Dimensional Digital Subtraction Angiography

PURPOSE: The author compared three-dimensional computed tomographic angiography with combined volume rendering technique (3D-CTA VR) with three-dimensional digital subtraction angiography (3D-DSA) in the detection and characterization of intracranial aneurysms, in order to assess the diagnostic capability of 3D-CTA VR. MATERIALS AND METHODS: This study included 50 patients with suspected intracranial aneurysm who underwent both 3D-CTA VR and 3D-DSA, and who were subsequently confirmed as having aneurysms by intracranial operation or other neurointerventional procedures. The detectability and the characteristics of the aneurysms, such as their aneurysmal neck, direction, and vasospasm of the adjacent vessels, were evaluated retrospectively. RESULTS: Sixty-five intracranial aneurysms were detected through surgery or other interventional procedures. 3D-DSA was more sensitive (96.92%) than 3D-CTA VR in the detection of the aneurysms. All of the aneurysms that were more than 3mm in size were detected with both techniques. 3D-DSA failed to reveal one posterior communicating artery aneurysm, while 3D-CTA VR missed three aneurysms. The aneurysmal necks were clearly visualized in 58 of 61 aneurysms (95.1%) on 3D-CTA VR, but all of the aneurysmal necks(100%) were clearly identified on 3D-DSA. CONCLUSION: 3D-CTA combined with VR technique showed good sensitivity for the depiction of intracranial aneurysms greater than 3 mm in size, and its usefulness in characterizing the aneurysms for surgical or endovascular treatment planning was equal to or less than that of 3D-DSA.

Detection of Hemorrhagic Transformation in Patients with Acute Cerebral Infarction: Comparison of CT with T1WI, FLAIR, and Gradient-Echo MR Imaging

PURPOSE: To determine the diagnostic accuracy of T1-weighted, FLAIR, and GRE MR imagings in the detection of hemorrhagic transformation in patients with acute cerebral infarction and to compare it with CT. MATERAILS AND METHODS: Fifty-three patients with acute territorial cerebral infarction were studied prospectively. All patients underwent nonenhanced CT and MRI including the T1-weighted, FLAIR, and GRE. Lesion conspicuity of hemorrhage was scored as follows: 0-none; 1-suspicious; 2-sure. CT and MR imagings were reviewed two radiologists respectively. The mean value of the lesion conspicuity in each CT and MR sequences was compared by means of a Wilcoxon signed ranks test. The time intervals between CT and MR imagings ranged from 3 to 14 hours (mean; 7.6 hours). RESULTS: Hemorrhagic transformation was detected on nonenhanced CT in 26 of 53 patients. In the detection of hemorrhage in patients with acute cerebral infarction, T1-weighted and FLAIR MR imagings were inferior to NECT (p<0.05). By contrast, lesion conspicuity of GRE MR imaging was not different from that of CT (p=0.5). In addition, lesion conspicuity of GRE MR imaging was greater than that of CT in five patients on reader A and two patients on reader B. CONCLUSION: GRE MR imaging was superior to T1-weighted and FLAIR MR imagings, equal to nonenhanced CT in the detection of hemorrhagic transformation in patients with acute cerebral infarction.

The Usefulness of Perfusion CT in Acute Cerebral Ischemic Infarction

PURPOSE: To determine the usefulness of cerebral perfusion computed tomography (CT) in patients with acute cerebral ischemic infarction. MATERIALS AND METHODS: Twelve patients with acute middle cerebral artery infarction underwent conventional CT and cerebral perfusion CT within 25 hours of the onset of symptoms. For each patient, perfusion CT scans were obtained at the levels of the basal ganglia and 1 cm caudal to them. Using special imaging software, perfusion imaging maps for cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to peak (TTP) were created, and the infarcted lesion was evaluated on each map. MTT and TTP delay times were measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Lesion size on each perfusion map was determined and compared with the value obtained by diffusionweighted MR imaging (DWMRI). RESULTS: In all patients, perfusion CT maps depicted the perfusion defect lesion, for which the MTT and TTP delay was remarkable. A comparison of lesion size between each perfusion map and DWMR images showed that the closest correlation involved CBF maps (8/12, 67%). On MTT maps, the lesion was larger than at DWMRI, suggesting that MTT mapping can be used to evaluate ischemic penumbra. CONCLUSION: Perfusion mapping facilitates the evaluation not only of the ischemic core and ischemic penumbra, but also of hemodynamic status in the area of the perfusion defect. This finding demonstrates that perfusion CT can be useful for the diagnosis and treatment of patients with acute cerebral ischemic infarction.

Assessment of Angiogenesis of Hepatic VX2 Carcinoma: Usefulness of Perfusion CT

PURPOSE: To investigate the perfusion characteristics of VX2 carcinoma and liver parenchyma in an animal model, and to evaluate the usefulness of perfusion CT in assessing the angiogenesis of hepatic VX2 carcinoma. MATERIALS AND METHODS: Ten rabbits (control, 5; VX2 carcinoma, 5) weighing 2.5 to 3.5 (average, 3.1) Kg were involved in this study. Between 7 and 14 days after implanting VX2 carcinoma, ultrasonography and CT were performed for the purpose of detecting this. Using the cine mode and involving four simultaneous sections, four perfusion CT images were obtained every second for 60 seconds. One radiologist measured the size of the region of interest (ROI) at each liver location, and using the time-density curves for each tumor and normal liver, semi-quantitative perfusion parameters -namely blood volume, mean transit time (MTT), blood flow, and time-to-peak enhancement-were determined. The microvascular densities (MVD) of VX2 tumors and normal liver were correlated with the perfusion CT findings. RESULTS: In the control group, there were no significant differences in perfusion parameters between the left and right hepatic lobes. In the VX2 carcinoma group, there were significant differences between the lobe containing the tumor and adjacent hepatic lobes with respect to blood volume (34.80 vs. 27.2 ml/100 g), MTT (14.1 vs. 19.4 sec), blood flow (119.7 vs. 84.3 ml/100 g/min), and time-to-peak (32.4 vs. 36.9 sec) (p<0.05). The blood volume (27.2 ml/100g) of the hepatic lobe with the VX2 tumor was higher than that of normal liver (22.8 ml/100 g) (p< 0.05), but blood flow (84.3 vs. 66.8 ml/100 g/min), MTT (19.4 vs. 21.3 sec) and time-to-peak (36.9 vs. 38.7 sec) values were not different. The MVD of VX2 tumors was higher than that of normal liver (p<0.05), and significantly higher than that of adjacent and contralateral liver (p<0.05). CONCLUSION: At perfusion CT, blood volume and blood flow of VX2 carcinomas increased more than those of normal liver, as were both mean transit time and time-to-peak. It was confirmed histopathologically that the angiogenesis of VX2 carcinoma was higher than that of normal liver. In conclusion, perfusion CT may be a practically useful diagnostic tool capable of reflecting the neoplastic angiogenesis of the liver.

The Usefulness of Air Insufflation Helical CT in Colorectal Cancer

PURPOSE: In patients with colorectal carcinoma, helical CT using air as a contrast agent provides axial images and a three-dimensional CT colonogram similar to that provided by barium enema. The purpose of this study was to assess the usefulness of air insufflation helical CT in colorectal cancer patients. MATERIALS AND METHODS: Thirty-three patients with colorectal carcinoma confirmed by surgery underwent air insufflation helical CT scanning after the infusion of air through the anus. In eleven who underwent barium studies, CT colonograms were also obtained. Two radiologists, who reached a consensus, analysed the detection rate, location and staging of the tumors; staging was based on the modified Dukes (Astler-Coller) classification. RESULTS: Using axial helical CT, the detection rate was 97%; staging was correct in 23 of the 33 patients, with an overall accuracy of 70%. Pathologic correlation was correct in 30 of the 33 cases (three were overestimated), and sensitivity, specificity and accuracy were 100%, 50%, and 91%, respectively. With regard to the involvement of lymph nodes, pathologic correlation was correct in 25 of the 33 patients; four were overestimated and four were underestimated. Sensitivity, specificity and accuracy were 69%, 80%, and 76%, respectively. The detection rate of CT colonography was 100%, but because in one case there was a discrepancy between CT colonography and barium enema as to the shape of the carcinoma, the agreement rate was 91%. CONCLUSION: Air insufflation helical CT, which provides a higher detection rate and more precise staging of colorectal carcinoma than the use of positive contrast materials and three dimensional depiction of tumor location, is helpful for the evaluation of colorectal carcinoma.

Acute Cerebral Infarction in a Rabbit Model: Perfusion and Diffusion MR Imaging

PURPOSE: The present study was undertaken to evaluate the usefulness of cerebral diffusion (DWI) and perfusion MR imaging (PWI) in rabbit models with hyperacute cerebral ischemic infarction. MATERIALS AND METHODS: Experimental cerebral infarction were induced by direct injection of mixture of Histoacryl glue, lipiodol, and tungsten powder into the internal cerebral artery of 6 New-Zealand white rabbits, and they underwent conventional T1 and T2 weighted MR imaging, DWI, and PWI within 1 hour after the occlusion of internal cerebral artery. The PWI scan for each rabbit was obtained at the level of lateral ventricle and 1cm cranial to the basal ganglia. By postprocessing using special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were obtained. The detection of infarcted lesion were evaluated on both perfusion maps and DWI. MTT difference time were measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. RESULTS: In all rabbits, there was no abnormal signal intensity on T2WI. But on DWI, abnormal high signal intensity, suggesting cerebral infarction, were detected in all rabbits. PWI (rCBV, CBF, and MTT map) also showed perfusion defect in all rabbits. In four rabbits, the calculated square of perfusion defect in MTT map is larger than that of CBF map and in two rabbits, the calculated size of perfusion defect in MTT map and CBF map is same. Any rabbits do not show larger perfusion defect on CBF map than MTT map. In comparison between CBF map and DWI, 3 rabbits show larger square of lesion on CBF map than on DWI. The others shows same square of lesion on both technique. The size of lesion shown in 6 MTT map were larger than DWI. In three cases, the size of lesion shown in CBF map is equal to DWI. But these were smaller than MTT map. The calculated square of lesion in CBF map, equal to that of DWI and smaller than MTT map was three. And in one case, the calculated square of perfusion defect in MTT map was largest, and that of DWI was smallest. CONCLUSION: DWI and PWI may be useful in diagnosing hyperacute cerebral ischemic infarction and in evaluating the cerebral hemodynamics in the rabbits.

Functional MR Imaging Using BOLD Technique in Patients with Brain Tumors

PURPOSE: To reveal clinical usefulness of functional MRI (fMRI) using sensorymotor and language stimuli for demonstrating anatomic relationship between sensorimotor or language cortices and lesions in the planning of brain tumor surgery. MATERIALS AND METHODS: This study included 12 right-handed patients with brain tumors in or around sensorimotor or language cortices. Eleven patients were evaluated with primary motor and sensory stimuli. Of these patients, six patients were also evaluated with language stimuli. One patient was evaluated with language stimuli only. For fMR imaging, a 1.5T scanner was used and the EPI BOLD technique was employed. For postprocessing image, the SPM99 program and a program made by our department was utilized. We evaluated whether sensorimotor and language stimuli activate sensorimotor and language cortices. And also, clinical efficacy of revealing anatomic relationship between cerebral cortices and lesions for planning neurosurgical operation were evaluated. Finally, we compared post-operative neurologic function with pre-operative neurologic function in same patients. RESULTS: The fMRI examination was successful in identifying the functional cortices and depicting anatomic relationship between functional cortices and lesions in all patients. In nine patients of 11 patients with identified sensorimotor cortices, postoperative grade of manual motor test was not changed, compared with preoperative grade. Whereas postoperative improved than preoperative grade in one patient of remaining two patients, postoperative aggravated than preoperative grade in the other. This result was due to atherosclerotic lacunar infarction, regardless of tumor resection. Postoperative deficit of language function was not found in seven patients with identified language cortices. CONCLUSION: fMRI could be a helpful method for determining the best approach to neurosurgical treatment in patients with brain tumors in or around sensorimotor or language cortices.

Enhancement Pattern of Focal Hepatic Tumors with Gadobenate Dimeglumine-Enhanced Delayed MR Imaging

PURPOSE: To investigate the enhancement pattern occurring at delayed gadobenate dimeglumine (Gd-BOPTA) MR imaging, as used to characterize focal hepatic tumors. MATERIALS AND METHODS: Forty patients with 64 focal hepatic tumors (32 hepatocellular carcinomas [HCC], 15 hemangiomas, 14 metastasis and 3 cholangiocarcinomas) underwent MR imaging before and 60 minutes after the intravenous administration of 0.1 ml/kg Gd-BOPTA. For all MR studies, a 1.5-T MR system was used, and T1-weighted in-phase gradient echo (GRE) imaging was porformed. The quantitative assessment of early and delayed images included determination of the signal-to-noise ratio (SNR), tumor-to-liver contrast-to-noise ratio (CNR), and degree of enhancement (DE). Two experienced radiologists evaluated lesion conspicuity and the pattern of contrast enhancement (CE), reaching their conclusions by consensus. RESULTS: At delayed imaging, SNR and CNR showed significant increases (p>0.05), and the DE of all lesions had also increased. Lesion conspicuity, however, was not significantly different between (p>0.05). The most common enhancement patterns seen at delayed imaging were inhomogeneous hypointense in HCCs, homogeneous iso- or hyperintense in hemangiomas, and target-like in metastases. CONCLUSION: At delayed imaging with Gd-BOPTA, tumors of both hepatocytic and non-hepatocytic origin showed enhancement, and in the characterization of focal hepatic lesions, observed differences in enhancement are thus of limited usefulness. However, the observed homogeneous iso- or hyperinteuse enhancement of hemangiomas, and the target-like enhancement of metastases, may help differentiate then from other tumors.