[en] To investigate significance of three dimension (3D) magnetic resonance (MR) lumbosacral radiculography by principles of the selective excitation technique (Proset) in the diagnosis of symptomatic foraminal stenosis. A total of 288 foramina in 48 patients were analyzed (from L3 4 to L5 S1). Conventional spin echo sequence and 3D coronal fast field echo sequences with selective water excitation by Proset were acquired. Through conventional MR imaging, the presence of lumbar foraminal stenosis was evaluated. Three morphologic changes (swelling, indentation, and tilting angle abnormality) of corresponding nerve roots were assessed on 3D MR lumbosacral radiculography. Relationships between the three morphologic findings and corresponding symptoms were evaluated. In 288 foramina, symptomatic and asymptomatic foraminal stenoses were found in 49 and 14 foramina, respectively. In symptomatic foraminal stenosis, swelling, indentation and tilting angle abnormality of the nerve root were found in 36, 18, and 10 foramina, respectively. One or more of the three findings was found in 46 foramina. In 12 foramina with asymptomatic foraminal stenosis, no morphologic changes were found. A statistically significant difference among three morphologic changes of nerve root in symptomatic foraminal stenosis was found (χ2 test, p < 0.001). 3D MR lumbosacral radiculography by Proset was useful for the detection of morphologic changes of the nerve root for the diagnosis of symptomatic foraminal stenosis

[en] We investigated the causes and mechanisms driving acute border zone infarctions using diffusion-weighted imaging (DWI). We analyzed DWI in 104 patients (male: 72 years, female: 32 years, age range: 44 to 84 years) with acute border zone infarction. The DWI patterns were classified as follows: pattern A-An acute border zone infarction combined with multiple small disseminated cortical infarctions, pattern B-An acute border zone infarction only. The most common cause of acute border zone infarctions was extracranial internal carotid artery (ICA) stenosis (45 cases, 43%). Other causes included middle cerebral artery stenosis (22 cases, 21%), intracranial ICA stenosis (14 cases, 13%), unknown, (12 cases 12%), iatrogenic (6 cases, 6%) and cardiogenic (5 cases, 5%), respectively. The most common pattern for DWI was pattern A (83 cases, 80%). We performed a transcranial Doppler in 7 of 75 cases (11%), and found at least 1 embolic pulse. The most common pattern of DWI for acute border zone infarction was pattern A. We propose that the mechanisms driving acute border zone infarctions are emboli coupled with hypoperfusion

[en] Although the neuroradiological findings of congenital cytomegalovirus (CMV) infection are well known, little has been reported concerning the imaging findings of paraventricular cysts occurring in patients with cytomegalovirus infection involving the brain. The purpose of this study is to describe the features of paraventricular cysts observed at MRI and ultrasonography. MR and ultrasonographic studies of ten patients with congenital cytomegalovirus infections involving the brain were retrospectively reviewed. Diagnosis was confirmed by positive culture of the virus in urine (n=4), the presence of CMV Ig G antibody (n=4), or positive CMV Ig M antibody (n=2), and on the basis of characteristic MR imaging findings. Initial MRI in all patients and initial ultrasonography in four of five with paraventricular cysts were performed. Three patients underwent follow-up MRI and ultrasonography for the evaluation of cystic change, and the size, location, bilaterality and morphology of the cysts were evaluated. Bilateral paraventricular cysts averaging 15 (range. 10-23) mm in size were found in five of the ten patients (50%). They were adjacent to the foramen of Monro in three cases, the occipital horn in one, an dthe temporal horn in one. MR imaging showed that the fluid content of all cysts was of similar signal intensity to cerebrospinal fluid (T1-WI, hypointense; T2-WI, hyperintense). The ultrasonographic findings varied: there was one pure cyst and one with a thick wall and septations, and two contained complex fluid. In three patients, follow up MRI and ultrasonography showed that the cysts disappeared after 4-23 months. Although paraventricular cysts may appear at MRI to be purely cystic, ultrasonography may indicate that their contents are more complex, or that septations are present

[en] The malignant transformation of an epidermoid cyst can be discovered at the same time as a pre-existing epidermoid cyst, or during a follow-up examination after an incomplete excision. We describe a rare case of malignant transformation of a cerebello-pontine angle epidermoid cyst which extended into the middle cerebellar peduncle

[en] To investigate the role of lumbosacral radiculography using 3-dimentional (3D) magnetic resonance (MR) rendering for diagnostic information of symptomatic extraforaminal stenosis in lumbosacral transitional vertebra. The study population consisted of 18 patients with symptomatic (n = 10) and asymptomatic extraforaminal stenosis (n = 8) in lumbosacral transitional vertebra. Each patient underwent 3D coronal fast-field echo sequences with selective water excitation using the principles of the selective excitation technique (Proset imaging). Morphologic changes of the L5 nerve roots at the symptomatic and asymptomatic extraforaminal stenosis were evaluated on 3D MR rendered images of the lumbosacral spine. Ten cases with symptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. On 3D MR lumbosacral radiculography, indentation of the L5 nerve roots was found in two cases, while swelling of the nerve roots was seen in eight cases at the exiting nerve root. Eight cases with asymptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. Based on 3D MR lumbosacral radiculography, indentation or swelling of the L5 nerve roots was not found in any cases with asymptomatic extraforaminal stenosis. Results from 3D MR lumbosacral radiculography Indicate the indentation or swelling of the L5 nerve root in symptomatic extraforaminal stenosis. Based on these findings, 3D MR radiculography may be helpful in the diagnosis of the symptomatic extraforaminal stenosis with lumbosacral transitional vertebra.

[en] Desmoplastic infantile ganglioglioma is an uncommon variety of ganglioglioma that shows evidence of glial and ganglionic differentiation accompanied by an extreme desmoplastic reaction. A 16-month-old girl was admitted with a six-day history of left hemiparesis. MR imaging demonstrated a large multiseptated cystic mass, with a solid portion, in the white matter of the right frontotemporoparietal lobe. After contrast injections, the solid portion was clearly enhanced. The presence of desmoplastic infantile ganglioglioma was confirmed by surgical resection. We describe the characteristic radiologic and pathologic features of desmoplastic infantile ganglioglioma, and include a review of the literature

[en] To evaluate MRI findings of Guillain-Barre syndrome. In six patients with Guillain-Barre syndrome diagnosed by clinical, cerebrospinal fluid and electrophysiologic findings, a retrospective review of MR findings was conducted. Follow-up MRI scans were carried out in two patients showing minimal clinical improvement. Marked or moderate enhancement of thickened nerve roots was seen in all cases on gadopentetate dimeglumine enhanced axial T1-weighted images. Two patterns were seen; one was even enhancement of both anterior and posterior nerve roots (n=1) and the other was enhancement of anterior nerve roots only (n=5). Enhancement and thickness of nerve roots was seen to have slightly decreased on MRI follow-up at 32 and 50 days; clinical and electrophysiologic examination showed minimal improvement. Although MRI findings of nerve root enhancement are nonspecific and can be seen in neoplastic and other inflammatory diseases, the enhancement of thickened anterior nerve roots within the cal sac suggests Guillain-Barre syndrome

[en] We report a case of dural-based intracranial primary mesenchymal chondrosarcoma, initially thought to be a meningioma. This rare tumor should be included in the differential diagnosis of an aggresive dural-based lesion occurring in a young adult. A 27-year-old man presented with headache, mausea and vomiting, first experienced months earlier. Pre-enhanced CT revealed the presence of a well-marginated isodense mass with dense calcifications in the frontoparietal convexity, while MR images depicted a lobulated extra-axial mass with peritumoral edema. At T1-weighted imaging, the signal intensity of the mass was slightly lower than of gray matter, while T2-weighted imaging demonstrated heterogeneous high signal intensity. Some portions of the tumor showed low signal intensity at all sequences, suggesting the presence of calcification. After the injection of contrast medium, heterogeneous enhancement was observed. We report the radiologic findings of an intracranial primary mesenchymal chondrosarcoma, confirmed pathologically

[en] FK506 is widely used as a potent immunosuppressive agent following organ transplantation. However, the use of FK506 is associated with a wide spectrum of neurotoxicity. FK506-induced cerebral infarctions have rarely been reported. We report here on a case of the acute cerebral infarction caused by vasospasm after FK506 administration in a kidney transplantation recipient. There were areas with increased signal intensity on the diffusion-weighted image. The areas showing increased signal intensity on the diffusion- and T2-weighted images demonstrated decreased signal intensity on the apparent diffusion coefficient mapping. MR angiography showed diffuse stenosis in both the anterior and middle cerebral arteries

[en] Linear sebaceous nevus syndrome, which is the association of nevus sebaceous of Jadassohn in the midfacial area with seizure and mental deficiency, has been reported in at least 100 cases. Hemimegalencephaly is a rare malformation consisting of unilateral hypertrophy of the brain, an abnormal gyral pattern, thickened cortex, white matter abnormality, and lateral ventricular dilatation. The authors report a case of linear sebaceous nevus syndrome with hemimegalencephaly, diagnosed on the basis of clinical data and brain MRI