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✓A desmoplastic infantile astrocytoma (DIA) is an extremely rare tumor that comprises a solid astrocytic tumor accompanied by a large cyst and involves the superficial cerebral cortex and leptomeninges in infants. The solid part of this type of tumor has been well described in various reports and books, but characteristics of the cystic portion have remained unclear. Because adequate resection is required to ensure a favorable prognosis, information about the cyst is very important for diagnostic purposes and surgical planning. The authors report on the clinical and histological features of the cyst in a case of a DIA. A 12-month-old boy presented with vomiting. Contrast-enhanced magnetic resonance imaging revealed a strongly enhancing single-lobed large cyst located in the deep white matter, under the solid part of the tumor attached to the dura mater of the left frontal lobe. Both the solid and cystic portions of the tumor were surgically removed. The border between the cyst wall and surrounding white matter was unclear. Histologically, the cyst wall was composed of gliosis representing a rough accumulation of reactive astrocytes, lymphocytes, and small capillary vessels in edematous parenchyma, but no tumor cells. The present case and previous reports suggest that the cyst does not contain tumor cells, even if strongly depicted on contrast-enhanced neuroimaging, and that a thickly enhancing cyst wall indicates gliosis with accumulation of numerous small vessels.

Background and purpose: Three-dimensional anisotropy contrast magnetic resonance axonography (3DAC) is a technique for diffusion weighted magnetic resonance imaging (DWI) that offers reliable visualization of the pyramidal tracts. This study evaluated condition of the pyramidal tract using 3DAC in glioblastoma patients with hemiparesis. Methods: In 18 glioblastoma patients before surgery, 3DAC findings of the pyramidal tract responsible for hemiparesis were compared with finding from proton density-weighted imaging (PDWI). To estimate extent of pyramidal tract destruction, fractional anisotropy (FA) values using diffusion tensor magnetic resonance imaging were examined for both the responsible and non-pathological pyramidal tracts. Results: In all five patients for whom PDWI indicated no hyperintense foci in the responsible pyramidal tract, 3DAC demonstrated no change in color. When PDWI revealed hyperintense foci, 3DAC showed two types of findings: no color change (five patients); or obscured dark area (six patients). When 3DAC showed a dark area, mean FA value in the responsible tract was significantly lower than that for the non-pathological tract.Conclusion: When PDWI indicates hyperintense foci on the pyramidal tract, 3DAC allows prediction of pyramidal tract condition, such as large tumor invasion.

Magnetic resonance (MR) imaging is an important diagnostic tool for neurosurgical diseases but susceptibility artifacts caused by biomaterial instrumentation frequently causes difficulty in visualizing postoperative changes. The susceptibility artifacts caused by neurosurgical biomaterials were compared quantitatively by 0.5, 1.5, and 3.0 Tesla MR imaging. MR imaging of uniform size and shape of pieces ceramic (zirconia), pure titanium, titanium alloy, and cobalt-based alloy was performed at 0.5, 1.5, and 3.0 Tesla. A linear region of interest was defined across the center of the biomaterial in the transverse direction, and the susceptibility artifact diameter was calculated. Susceptibility artifacts developed around all biomaterials at all magnetic field strengths. The artifact diameters caused by pure titanium, titanium alloy, and cobalt-based alloy increased in the order of 0.5, 1.5, to 3.0 Tesla magnetic fields. The artifact diameter of ceramic was not influenced by magnetic field strength, and was the smallest of all biomaterials at all magnetic field strengths. The artifacts caused by biomaterials except ceramic increase with the magnetic field strength. Ceramic instrumentation will minimize artifacts in all magnetic fields.

Background: The efficacy of surgical evacuation in patients with intracerebral hemorrhage (ICH) remains unclear for recovery of motor function. The relationship between improvement of motor function outcome and sequential change of fractional anisotropy (FA) values was investigated in patients with ICH, to explore whether motor function outcome can be predicted in the early phase. Indication of the surgical hematoma evacuation was also considered. Methods: This prospective study included 23 patients with ICH. All patients underwent diffusion tensor imaging to measure the FA value five times: within 3 days, day 14, day 30, day 60, and day 90 after the onset. The regions of interest were determined on the b = 0 step of the echo planar imaging scans in the bilateral cerebral peduncles and were automatically transferred onto the FA images. The FA value was then calculated for each patient. Patients were divided into good and poor recovery groups according to the motor function outcome on day 90. Results: The mean FA value of the poor recovery group gradually decreased until day 90, but remained unchanged in the good recovery group. The mean FA value on day 3 was significantly higher (p < 0.001) in the good recovery group (0.745 ± 0.0073) than in the poor recovery group (0.682 ± 0.0090). Receiver operating characteristic curve analysis showed that the FA value on day 3 could predict motor function outcome with a sensitivity of 100% and a specificity of 77.8% at an FA value of 0.7 on day 3. Conclusion: The main finding of this study was that the FA values of the cerebral peduncle on the pathological side in patients with ICH on day 3 could predict the motor function outcome on day 90.

A Case of osteoma with horn shape is rare. A 79-years-old man, in whom the osteoma with horn shape was not demonstrated three years ago. Slowly, the osteoma becomes accompanied with pain, and the slow growth of a horn. Computed tomography showed a bone tumor arising from the right parietal bone, but, the patient didn't request treatment. The osteoma changed its form, and an ulcer developed. The patient eventually accepted our advice about surgery, but with bad grace. On operation, the tumor proved to be hard. The tumor was detaches from the skull and the surrounding cranial bone was removed. The histological diagnosis was that it was a case of a compact type osteoma. The postoperative recovery of the patient was satisfactory and his pain disappeared, but, he died of pneumonia on the 40th postoperative day. We believe that the osteoma in our case must have grown slowly with time and ossification of the surrounding tissue.

This study investigated the changes in the valve pressure setting of several magnetic pressure-programmable valves after exposure to a 3-tesla magnetic field.Five each of four types of pressure-programmable shunt valves were tested: Sophy Polaris, Sophy SM8, Codman-Hakim, and Medtronic Strata. First, the valves were advanced toward the 3-tesla static magnetic field. Second, T1-, T2-, and diffusion-weighted magnetic resonance (MR) images were generated with a radiofrequency magnetic field. Any changes in the pressure setting were observed by visual inspection with a compass or radiography. The pressure settings were changed after exposure to the static magnetic field in all programmable valves except for the Sophy Polaris. All pressure settings studied were unchanged after exposure to both static and radiofrequency magnetic fields (T1-, T2-, and diffusion-weighted MR imaging) in the Sophy Polaris.The Sophy Polaris valve allows shunt-dependent patients who need a programmable valve to undergo 3-tesla MR imaging.

A 45-year-old female presented a peripheral nerve sheath tumor (MPNST), which had progressed to malignancy from a neurofibroma arising in the left cervical vagus nerve. Neuroimaging showed that a tumor grew in the left neck area of the patient, involving the internal carotid and vertebral arteries, and invading the intracranium through the left jugular foramen. The tumor was extensively removed using a combination of the lateral suboccipital approach and the neck incision, and the frontotemporal approach accompanied with EC-IC highflow bypass and EC-MCA anastomosis. Postoperatively, pathological features demonstrated a MPNST arising from the cervical vagus nerve. Here, we discuss the clinical behavior of MPNST by quoting previous reports, and conclude by emphasizing 2 points in the treatment of MPNST; 1) that prognosis of patients with MPNST is greatly affected by the time between presenting symptoms and diagnosis, and 2) that it is very important to carefully observe neurofibroma patients, because there is a possibility of progression to malignant MPNST.