Impact of Brain MRI Markers on Major and Mild Vascular Cognitive Impairment in CADASIL

Background@#Cognitive impairment is the second most common clinical manifestation in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, understanding of cognitive impairment in CADASIL has been hampered by lack of consensus on diagnosis of vascular cognitive impairment (VCI). We used vascular impairment of cognition classification consensus study principles (VICCCS-1) and protocols (VICCCS-2) to assess the cognitive impairment in CADASIL. We also evaluated the impact of MRI markers on major and mild VCI in CADASIL. @*Methods@#We prospectively recruited 64 patients who underwent standardized brain MRI and detailed neuropsychological test. MRI analysis included number of lacunes, number of cerebral microbleeds (CMB), normalized volume of white-matter hyperintensities (nWMH), and brain parenchymal fraction (BPF). BPF has been used to measure brain atrophy. The patients were divided into three groups: those with normal cognition (CADASIL-NC, n=14), those with mild VCI (CADASIL-mild VCI, n=38), and those with major VCI (CADASIL-major VCI, n=11). @*Results@#The three groups differed according to age, with the major VCI group being older. The major VCI group had more lacunes, more CMB, more extensive white matter lesions and lower BPF than NC group. There were no significant differences between NC and mild VCI groups in BPF. BPF and age were the independent predictors of major VCI. There was a tendency that women were at higher risk for mild VCI, though it did not reach statistical significance. Women were older than men, but had lower number of lacunes in mild VCI. @*Conclusions@#These findings suggest that brain atrophy and age are the main predictors of major VCI in CADASIL.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1–2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Glyphosate-Induced Encephalopathy: A Case Report

No abstract available.

Recurrent Painful Ophthalmoplegic Neuropathy: a Case Report

Upon review, it is noted that recurrent painful ophthalmoplegic neuropathy (RPON) is a rare neurological syndrome characterized by recurrent unilateral headaches and painful ophthalmoplegia of the ipsilateral oculomotor nerve. As seen on brain MRI, thickening and enhancement of the oculomotor cranial nerve can be observed in these cases. We experienced a case of RPON in an adult patient who showed thickening and enhancement of the oculomotor nerve on gadolinium-enhanced 3D-FLAIR image. The authors report a case of RPON with a review of the literature.

Venous Thromboembolism Following Acute Ischemic Stroke: A Prospective Incidence Study

BACKGROUND: Asians were known to have a relatively lower incidence of venous thromboembolism (VTE), and there is insufficient evidence to suggest a specific D-dimer threshold level for screening VTE in patients with acute stroke. METHODS: We prospectively enrolled patients with acute ischemic stroke admitted to Jeju National University Hospital. The inclusion criteria were: 1) aged ≥18 years, 2) admission within seven days of symptom onset, and 3) an initial National Institute of Health Stroke Scale (NIHSS) score >1 for the affected lower limb. Ultrasound scans of the lower limbs and plasma D-dimer assays were performed on days 7–14 and 15–28 after stroke onset. RESULTS: Of 285 patients admitted during the study period, 52 patients met inclusion criteria (mean age 74.5, male 40.4%, median initial NIHSS score 12, and unable to walk unassisted at discharge 76.9%). During 7–14 days, 23 of 52 patients (44.2%) had a D-dimer level above 1.57 mg/L, and 9.6% had a level above 5.50 mg/L. Proximal deep vein thrombosis (DVT) was detected in 3 patients (5.8%, 95% confidence Interval 1.2–16.0%) on ultrasound examination. All DVTs were found in elderly female patients with severe leg weakness. No patient was diagnosed with pulmonary embolism during the study period. CONCLUSION: The incidence of VTE seems to be very low among Korean patients with acute ischemic stroke. Advanced age, female sex, and severe leg weakness were important risk factors for developing DVT in this study.

Feasibility of Quadruple Arterial Phase of Motion Insensitive Radial Volumetric Imaging Breath-Hold Examination with k-Space Weighted Image Contrast in the Detection of Hepatocellular Carcinoma in Patients with Chronic Liver Disease

PURPOSE@#To evaluate the detection performance of hepatocellular carcinoma and image quality in patients with chronic liver disease with quadruple arterial MR imaging using radial volumetric imaging breath-hold examination (VIBE) with k-space weighted image contrast (KWIC).@*MATERIALS AND METHODS@#Forty-four patients underwent liver MR examinations with quadruple arterial imaging using radial VIBE-KWIC sequence (full-frame and four sub-frame images). Diagnostic performance was evaluated with receiver operating characteristics (ROC) for detection of hepatocellular carcinoma. The image quality and severity of artifact were scored by using the five-point scale.@*RESULTS@#The area under the ROC curve (Az) value of Hepatocelluar Carcinoma (HCC) detectability was the highest on third sub-frame images, followed by full-frame images. The Az values of third sub-frame and full-frame about the detection of HCC were statistically significantly different from the Az value of first sub-frame images. The full-frame and four sub-frame images showed acceptable image quality and low degree artifact with rating of higher than grade 3.@*CONCLUSION@#Quadruple arterial MRI using radial VIBE-KWIC is a feasible method for detecting hepatocellular carcinoma in patients with chronic liver disease without deterioration of image quality. The third sub-frame and full-frame image are superior to other sub-frame images in detecting hepatocellular carcinoma.

Optimization of the Flip Angle and Scan Timing in Hepatobiliary Phase Imaging Using T1-Weighted, CAIPIRINHA GRE Imaging

PURPOSE: This study was designed to optimize the flip angle (FA) and scan timing of the hepatobiliary phase (HBP) using the 3D T1-weighted, gradient-echo (GRE) imaging with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique on gadoxetic acid-enhanced 3T liver MR imaging. MATERIALS AND METHODS: Sixty-two patients who underwent gadoxetic acid-enhanced 3T liver MR imaging were included in this study. Four 3D T1-weighted GRE imaging studies using the CAIPIRINHA technique and FAs of 9° and 13° were acquired during HBP at 15 and 20 min after intravenous injection of gadoxetic acid. Two abdominal radiologists, who were blinded to the FA and the timing of image acquisition, assessed the sharpness of liver edge, hepatic vessel clarity, lesion conspicuity, artifact severity, and overall image quality using a five-point scale. Quantitative analysis was performed by another radiologist to estimate the relative liver enhancement (RLE) and the signal-to-noise ratio (SNR). Statistical analyses were performed using the Wilcoxon signed rank test and one-way analysis of variance. RESULTS: The scores of the HBP with an FA of 13° during the same delayed time were significantly higher than those of the HBP with an FA of 9° in all the assessment items (P < 0.01). In terms of the delay time, images at the same FA obtained with a 20-min-HBP showed better quality than those obtained with a 15-min-HBP. There was no significant difference in qualitative scores between the 20-min-HBP and the 15-min-HBP images in the non-liver cirrhosis (LC) group except for the hepatic vessel clarity score with 9° FA. In the quantitative analysis, a statistically significant difference was found in the degree of RLE in the four HBP images (P = 0.012). However, in the subgroup analysis, no significant difference in RLE was found in the four HBP images in either the LC or the non-LC groups. The SNR did not differ significantly in the four HBP images. In the subgroup analysis, 20-min-HBP imaging with a 13° FA showed the highest SNR value in the LC-group, whereas 15-min-HBP imaging with a 13° FA showed the best value of SNR in the non-LC group. CONCLUSION: The use of a moderately high FA improves the image quality and lesion conspicuity on 3D, T1-weighted GRE imaging using the CAIPIRINHA technique on gadoxetic acid, 3T liver MR imaging. In patients with normal liver function, the 15-min-HBP with a 13° FA represents a feasible option without a significant decrease in image quality.

Phenotypic Features of Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy Subjects with R544C Mutation

BACKGROUND AND PURPOSE: Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most-common single gene disorder of cerebral small vessel disease. There is no definite evidence of genotype-phenotype correlation in CADASIL. However, recent studies have shown the unique phenotypic feature of NOTCH3 R544C mutation. METHODS: We investigated the phenotypic spectrum of NOTCH3 R544C mutation in 73 CADASIL patients in Jeju between April 2012 and January 2014. RESULTS: Of the 73 subjects from 60 unrelated families included in this study, 40 (55%) were men. The mean age of the subjects was 62.2±12.2 (range 34-86 years). Cerebral infarction was the most frequent manifestation (37%), followed by cognitive impairment (32%), headache (17%), psychiatric symptom (16%), intracerebral hemorrhage (12%), transient ischemic attack (7%), and seizure (1%). The mean age of the subjects with ischemic or hemorrhagic episodes was 64.9±10.9 (range 41-86 years). A diagnosis of dementia was made in 12 subjects (16%). The mean age of the subjects with dementia was 75.6±6.5 (range 62-86 years). About 3% of subjects were unable to walk without assistance at assessment. Only one subject had developed chronic headache before the 40s. CONCLUSIONS: Our data support the hypothesis that CADASIL patients with R544C mutation in Jeju have relatively late onset disease.

Imaging Features of Nasal-Type Natural Killler/T-cell Lymphomas: Frequent Involvement of Skin and Subcutaneous Tissue

PURPOSE: We wanted to evaluate the radiologic characteristics of nasal-type NK/T cell lymphomas. MATERIALS AND METHODS: We reviewed twenty-one cases of pathologically proven nasal-type NK/T-cell lymphomas. CT scans were obtained for 21 patients, MR image were obtained for 3 patients, and both CT and MR scans were obtained for 3 patients. The imaging features regarding patterns of the masses, extension to adjacent tissue, bony changes and the degree of contrast enhancement were evaluated. RESULTS: All of the 21 patients had diffuse mucosal thickening and 12 patients (12/21, 57%) also had polypoid masses. Nasal cavity lesions showed extension to the adjacent tissue in 20 cases (20/21, 95%). Adjacent bone erosion or destruction was noted in 14 cases (14/21, 67%) and the bone destruction was mild. CONCLUSION: Nasal-type NK/T-cell lymphomas revealed a tendency to involve the superficial soft tissue and to extend into the adjacent structures. The typical imaging features of nasal-type NK/T-cell lymphoma were diffuse infiltrative lesion with or without polypoid masses in the nasal cavity and frequently extension to adjacent soft tissue, and especially the subcutaneous tissue.

Blood Loss of Image-free Navigation Assisted Minimal Invasive total Knee Arthroplasty

PURPOSE: To assess blood loss and transfusion between Navigation assisted minimally invasive total knee arthroplasty (TKA) performed with immediate release of drain and 1-hour - delayed release of drain. MATERIALS AND METHODS: We carried out a prospective randomised study to evaluate the blood loss in 100 knees having a Navigation-assisted minimally invasive TKA by dividing into two groups, one having a immediate release of drain (group A) and the other having a 1 hour-delayed release of drain(group B). All patients had a unilateral primary TKA using cemented type. RESULTS: The mean drainage of blood was 464.9 ml in a immediate release of drain group and 409.1ml in 1 hour-delayed release of drain group. This difference was not statistically significant (p=0.117). The pre- and postoperative hemoglobin were mean 13.36g/dl and 10.77 g/dl in group A, mean 12.8 g/dl and 10.37 g/dl in group B. All patients were not transfused in intra- and post operation. CONCLUSION: There was no significant difference in total blood loss of drain and pre- and postoperative hemoglobin between the two groups by the Navigation-assisted minimally invasive TKA. All patients were not transfused in intra- and post operation.

Encoding and Retrieval of Words and Scenes Assessed by Functional MRI in Normal Right-Handed Volunteers / 대한간질학회지

PURPOSE: To find the activation patterns of frontal and medial temporal lobe during memory tasks (encoding and retrieval) with novel stimuli (words, scenes) in normal right-handed volunteers. Another aim is to examine which memory paradigms and processes are effective to activate medial temporal lobe. METHODS: We included 10 right-handed normal volunteers. Stimuli consisted of encoding and retrieval of novel word (15 items)/novel scenes (15 items). During scanning, each stimulus was presented for 2000 ms. Imaging was performed on 1.5 GE scanner. Group analysis was performed in volunteers with SPM 2 (uncorrected p10). RESULTS: Scenes encoding and retrieval activated both medial temporal lobes, more on the right side. Word encoding activated predominantly dominant frontal lobe, but failed to activate the medial temporal lobes. The word stimuli activated more the frontal lobe than the picture stimuli. Retrieval process activated more the medial temporal lobe than encoding process. CONCLUSION: Our results showed that the scenes encoding/retrieval and word retrieval are useful to activate the medial temporal lobe and word encoding is useful for activating dominant frontal lobe. Further studies will be necessary in patient groups with unilateral temporal lobe lesion to document the usefulness of this study.

Neurological Complications Following Liver Transplant: A Pictorial Review of Radiological and Clinical Findings

Neurological complications are a rare but important and significant source of information about morbidity and mortality in liver transplant patients. Based on the clinical and radiological findings of 21 patients, neurological complications were categorized into five main groups; focal hemorrhagic or occlusive complications (n=11); diffuse hypoxic-ischemic injury (n=3); hypertensive encephalopathy (n=1); central pontine or extra-pontine myelinolysis (n=4); and infection (n=2). Neurological manifestations varied according to the location of the lesion, although seizures were the most common manifestation. In this pictorial review, we illustrate the radiological findings, focusing on MR and CT images, of a spectrum of neurological complications following liver transplants, as well as their clinical correlations.

MR Imaging of Solitary Fibrous Tumors in the Head and Neck

OBJECTIVE: Solitary fibrous tumor (SFT) is a very rare tumor. The purpose of this study is to determine the MR imaging features of SFT in the intracranial and extracranial head and neck regions. MATERIALS AND METHODS: We retrospectively reviewed six MR images and two CT images of six histologically proven cases of SFT that occurred in four men and two women, and their ages ranged from 46 to 59 years. These imaging findings were correlated with the microscopic findings of their surgical specimens. RESULTS: Six SFTs arose in the meninges (the petrous ridge and the pituitary fossa), the parotid gland, the parapharyngeal space, the buccal space and the maxillary sinus. On the MR images, SFTs in the intracranial and extracranial head and neck regions were mostly isointense to the muscle on the T1-weighted images, they were hyperintense on the T2-weighted images and they all had intense enhancement. On the T1- and T2-weighted images, hypointense lines were observed within in five SFTs. On the CT images, the SFTs were hypodense to the muscle on the unenhanced images and they were heterogeneously enhanced on the contrast-enhanced images. An exceptional case of pituitary SFT was hypointense on the T2-weighted images and it was hyperdense on the unenhanced CT images, which correlated with the increased collagenous component and the cellular compactness. CONCLUSION: The imaging features of SFT are nonspecific; however, SFT should be included in the differential diagnosis of masses involving the intracranial and extracranial head and neck regions.

Autogenous Bone Graft for Medial Tibial Bone Defect in Total Knee Arthroplasty

PURPOSE: To evaluate clinical and radiographic results associated with the use of autogenous bone graft with preservation of cortical bone in the patients with severe bone defect of the proximal medial tibia in total knee arthroplasty. MATERIALS AND METHODS: From January 2000 to June 2003, thirty three primary total knee arthroplasty were performed with autogenous bone graft for severe peripheral defect of the proximal medial tibia. After sclerotic bone of defect site was removed by the burr, reconstruction of medial wall was done by use of resected bone, which was fixed by wedge-shaped bone. Autogenous cancellous bone was grafted in the central type bone defect area. We reviewed the result using the HSS knee rating scores and observed the radiographic changes. RESULTS: The mean HSS knee rating score was 43.5 preoperatively and was 91.3 at last follow-up. Radiologically, union of the tibial bone grafts were impossible to determine, but there were no evidence of the displacement of grafted bone, osteolysis and loosening of the inserted implants. CONCLUSION: The method of autogenous bone graft applied with preservation of cortical bone and wedge bone graft could be supposed as useful in the reconstruction of the tibial bone defects as well as in the stability of the tibial component.

Comparative Analysis of Image-free Navigation System-Assisted TKA and Conventional TKA

PURPOSE: To compare the roentgenographic results between Image-free navigation system-assisted total knee arthroplasty (TKA) using the OrthoPilot(R) and conventional TKA. MATERIALS AND METHODS: Of 120 primary TKA that operated by one surgeon, 60 cases were operated with a Image-free navigation system (OrthoPilot(R) 4.0, Aesculap, Tuttlingen, Germany) (group A) and 60 cases were operated with conventional method (manual alignment system) (group B). The alignment of the lower extremity and the position of the components were determined on postoperative long-leg standing anteroposterior radiogram and lateral radiogram. RESULTS: Mechanical axis was significantly more accurate in group A than group B(95% compared with 80%). The coronal inclination of femoral component to mechanical axis (theta) was significantly more accurate in group A than group B(96.7% compared with 80%). There were no significant differences between two groups in the sagittal inclination of femoral component(gamma), the coronal inclination of tibial component (beta) and the sagittal inclination of tibial component(delta). In all five measurements being excellently implanted, a significantly higher number was in group A(60% compared with 40%). CONCLUSION: Image-free navigation system-assisted TKA using the OrthoPilot(R) led to significantly increased precision of restoration of the alignment of the lower extremity and the position of the components compared with the conventional method. Potential benefits in long-term outcome and functional improvement require further investigation.

CSF Flow Quantification of the Cerebral Aqueduct in Normal Volunteers Using Phase Contrast Cine MR Imaging

OBJECTIVE: To evaluate whether the results of cerebrospinal fluid (CSF) flow quantification differ according to the anatomical location of the cerebral aqueduct that is used and the background baseline region that is selected. MATERIALS AND METHODS: The CSF hydrodynamics of eleven healthy volunteers (mean age = 29.6 years) were investigated on a 1.5T MRI system. Velocity maps were acquired perpendicular to the cerebral aqueduct at three different anatomical levels: the inlet, ampulla and pars posterior. The pulse sequence was a prospectively triggered cardiac-gated flow compensated gradient-echo technique. Region-of-interest (ROI) analysis was performed for the CSF hydrodynamics, including the peak systolic velocity and mean flow on the phase images. The selection of the background baseline regions was done based on measurements made in two different areas, namely the anterior midbrain and temporal lobe, for 10 subjects. RESULTS: The mean peak systolic velocities showed a tendency to increase from the superior to the inferior aqueduct, irrespective of the background baseline region, with the range being from 3.30 cm/sec to 4.08 cm/sec. However, these differences were not statistically significant. In the case of the mean flow, the highest mean value was observed at the mid-portion of the ampulla (0.03 cm3/sec) in conjunction with the baseline ROI at the anterior midbrain. However, no other differences were observed among the mean flows according to the location of the cerebral aqueduct or the baseline ROI. CONCLUSION: We obtained a set of reference data of the CSF peak velocity and mean flow through the cerebral aqueduct in young healthy volunteers. Although the peak systolic velocity and mean flow of the CSF differed somewhat according to the level of the cerebral aqueduct at which the measurement was made, this difference was not statistically significant.

Localized 1H-MR Spectroscopy in Moyamoya Disease before and after Revascularization Surgery

OBJECTIVE: To evaluate, using localized proton magnetic resonance spectroscopy (1H-MRS), the cerebral metabolic change apparent after revascularization surgery in patients with moyamoya disease. MATERIALS AND METHODS: Sixteen children with moyamoya disease and eight age-matched normal controls underwent MR imaging, MR angiography, conventional angiography, and 99mTc- ECD SPECT. Frontal white matter and the basal ganglia of both hemispheres were subjected to localized 1H-MRS, and after revascularization surgery, four patients underwent follow-up 1H-MRS. RESULTS: Decreased NAA/Cr ratios (1.35+/-0.14 in patients vs. 1.55+/-0.24 in controls) and Cho/Cr ratios (0.96+/-0.13 in patients vs. 1.10+/-0.11 in controls) were observed in frontal white matter. After revascularization surgery, NAA/Cr and Cho/Cr ratios in this region increased. In the basal ganglia, there is no abnormal metabolic ratios. CONCLUSION: Localized 1H-MRS revealed abnormal metabolic change in both hemispheres of children with moyamoya disease. Because of its non-invasive nature, 1H-MRS is potentially useful for the preoperative evaluation of metabolic abnormalities and their postoperative monitoring.

Ultrasonography-guided Fine Needle Aspirations of Thyroid Incidentaloma: Correlation with Pathologic Findings / 대한내분비외과학회지

PURPOSE: There are many reports that diagnostic accuracy of fine needle aspiration (FNA) of thyroid is improved with ultrasound guidance, especially for impalpable nodules. Despite its general acceptance, routine use of ultrasound guided fine needle aspiration (USGFNA) has been the source of much controversy due to the lack of large-scale studies and lack of data on the natural course of welldifferentiated thyroid cancer of small size. METHODS: The aim of our study was to define the rate of malignancy in relatively large numbers of patients with incidentally detected impalpable thyroid nodules and to assess the extent of disease in patients with suspicious or malignant cytology on USGFNA of thyroid nodules by surgery. We retrospectively reviewed the medical records of the 267 patients who underwent USGFNA of incidental thyroid nodules from January 2000 through December 2001. RESULTS: Three hundred and seventeen nodules from 267 patients were aspirated. The average size of nodules was 0.9±0.3 cm, a range of 0.2 cm to 1.5 cm. All 317 lesions were impalpable. Cytological diagnosis included 101 inadequate specimen (32%), 139 benign (44%), 29 indeterminate (9%), 4 suspicious of follicular or Hrthle cell neoplasm (1%), 42 papillary carcinoma (13%), and 2 others. The size of the nodule was not related to the probability of getting an adequate specimen for cytological diagnosis. Forty of 48 patients with suspicious or malignant cytology underwent surgery. All 35 patients with a cytological diagnosis of papillary carcinoma were confirmed to have papillary carcinoma on histological results. One of 3 patients with a cytological diagnosis of follicular neoplasm had a follicular carcinoma. In 36 patients with well-differentiated thyroid cancer, extrathyroidal extension was observed in 44% (16/36), regional lymph node metastasis was found in 50% (18/36), and multifocal tumors were found in 39% (14/36). CONCLUSION: The rate of malignancy in incidentally detected impalpable thyroid nodules was 12% in retrospective analysis of our patients. Among those, 69% (25/36) of patients had either extrathyroidal extension or regional node involvement and 39% had multifocal tumors at surgery. This suggests that the small size itself could not guarantee a good prognosis in incidentally found thyroid cancers. USGFNA is a useful diagnostic method in those patients.

Preoperative transarterial embolization of hypervascular vertebral tumor with permanent particles / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the safety and value of preoperative transarterial embolization of hypervascular vertebral tumors.</p><p><b>METHODS</b>Sixteen patients with hypervascular vertebral tumors underwent transarterial embolization before surgery. The lesions were located between the middle cervical and lower lumbar spine. Forty-one arteries were embolized with permanent particles injected through a microcatheter, including polyvinyl alcohol (PVA) particles (150 - 500 micro m) in 25 arteries and Dextran particles (150 - 350 micro m) in 16. Of these, 31 had pieces of gelatin sponge added for proximal pedicled embolization. The criteria for judging the effectiveness of embolization were completeness of tumor removal and estimated blood loss during surgery.</p><p><b>RESULTS</b>The particles were injected into the tumor feeders through superselection in 17 arteries or flow control in 24. Tumor embolization was defined as "total" in five patients, "nearly total" in eight, "subtotal" in two, and "partial" in another. There were no symptomatic complications associated with embolization. Tumors were entirely removed in all patients. The average estimated blood loss during surgery was 1510 ml (range of 200 - 6000 ml) for all 16 patients.</p><p><b>CONCLUSION</b>Preoperative embolization of hypervascular vertebral tumors is safe and effective. It can make complete resection of a tumor possible and can make a previously unresectable tumor resectable. Superselection or flow control is necessary to achieve effective devascularization and to avoid complications.</p>

MR Imaging of Optic Chiasmatic Glioma

PURPOSE: To evaluate the MR findings of optic chiasmatic glioma (OCG). MATERIALS AND METHODS: MR images were reviewed in 14 patients with histologically proven OCGs and one with neurofibromatosis type 1 (male: female=8:7, mean age=8.5 years). Tumors were evaluated retrospectively with respect to their size, involvement of the optic pathway, transverse/vertical diameter ratio based on the coronal plane, signal intensities, enhancement pattern, and the presence of a cyst or calcification. RESULTS: Tumors was measured 1.7-5.5 (mean, 3.3) cm in maximum diameter. In ten patients, the optic tracts were involved, and in three, the optic nerves. In 12 patients, tumors had a transverse/vertical diameter ratio of over one, and showed iso (n=5) or low signal intensity (n= 10) compared with gray matter at T1-weighted imaging and high signal intensity (n=15) at T2-weighted imaging. Cyst formations were seen in eight patients, and tumors were enhanced strongly and homogeneously in nine and peripherally in four. In seven there was associated hydrocephalus, and in one, calcification. CONCLUSION: OCG is a suprasellar tumor which can extend into the optic pathway, has a transverse/vertical diameter ratio of more than one, and shows strong and homogeneous enhancement. These MR imaging findings are useful for the differentiation of OCG from other suprasellar tumors.