Macro- and microstructural changes in patients with spinocerebellar ataxia type 6: assessment of phylogenetic subdivisions of the cerebellum and the brain stem.

BACKGROUND AND PURPOSE: Site-specific degeneration patterns of the infratentorial brain in relation to phylogenetic origins may relate to symptoms in patients with spinocerebellar degeneration, but the patterns are still unclear. We investigated macro- and microstructural changes of the infratentorial brain based on phylogenetic origins and their correlation with symptoms in patients with spinocerebellar ataxia type 6. MATERIALS AND METHODS: MR images of 9 patients with spinocerebellar ataxia type 6 and 9 age- and sex-matched controls were obtained. We divided the infratentorial brain on the basis of phylogenetic origins and performed an atlas-based analysis. Comparisons of the 2 groups and a correlation analysis assessed with the International Cooperative Ataxia Rating Scale excluding age effects were performed. RESULTS: A significant decrease of fractional volume and an increase of mean diffusivity were seen in all subdivisions of the cerebellum and in all the cerebellar peduncles except mean diffusivity in the inferior cerebellar peduncle in patients compared with controls (P < .0001 to <.05). The bilateral anterior lobes showed the strongest atrophy. Fractional volume decreased mainly in old regions, whereas mean diffusivity increased mainly in new regions of the cerebellum. Reflecting this tendency, the International Cooperative Ataxia Rating Scale total score showed strong correlations in fractional volume in the right flocculonodular lobe and the bilateral deep structures and in mean diffusivity in the bilateral posterior lobes (r = 0.73 to ±0.87). CONCLUSIONS: We found characteristic macro- and microstructural changes, depending on phylogenetic regions of the infratentorial brain, that strongly correlated with clinical symptoms in patients with spinocerebellar ataxia type 6.

Orbital masses: the usefulness of diffusion-weighted imaging in lesion categorization.

INTRODUCTION: Diffusion-weighted imaging (DWI) produces contrast among different kinds of tissues according to their diffusibility characteristics. The purpose of our study was to evaluate the role of DWI including measurement of apparent diffusion coefficient (ADC) values in recognizing benignancy or malignancy of orbital masses. METHODS: A total of 39 orbital masses were evaluated visually for signal characteristics on DWI and ADC maps. ADC values were calculated for each lesion. Visual signal characteristics were compared using the Fisher exact test. Receiver operating characteristic (ROC) analysis was carried out to determine sensitivity and specificity for distinguishing malignant from benign lesions using ADC values. The Mann-Whitney U test was applied to compare the ADC values between orbital lymphomas and idiopathic orbital inflammatory (IOI) lesions, and between optic nerve sheath meningiomas and gliomas. RESULTS: Visual assessment revealed no significant difference between benign and malignant lesions on DWI (p-value = 0.66). However, visual assessment of ADC maps revealed a statistically significant (p-value ≤ 0.0001) between benign and malignant lesions. ROC analysis showed a sensitivity of 83.33 % and a specificity of 85.71 % when using an optimal cut off ADC value of 0.84 × 10(-3) mm(2)/s for differentiating malignant from benign lesions. Significant differences in mean ADC values were observed between lymphomas and IOI lesions (p-value = 0.05), and between optic nerve sheath meningiomas and gliomas (p-value = 0.03). CONCLUSION: DWI is useful for differentiating malignant and benign orbital tumors if accompanied by visual assessment of ADC maps and ADC value calculations.

Evaluation of cervical myelopathy using apparent diffusion coefficient measured by diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Intramedullary high signal intensity on T2-weighted imaging was frequently observed in patients with CSM, although this finding does not well correlate with severity or prognosis of CSM. Instead of this nonquantitative information, another measure for CSM is desired. The work was focused primarily on assessing the relationships between ADC values and clinical and radiologic severity for the diagnosis of CSM. MATERIALS AND METHODS: The relationship between ADC values measured in the spinal cord at 322 intervertebral levels of 66 patients and clinical factors were analyzed. RESULTS: ADC values in the spinal cord significantly increased with the degree of spinal cord compression and decreased with time after decompression surgery. Patients with higher ADC values had lower preoperative JOA scores and tended to show poorer clinical recovery. CONCLUSIONS: ADC values appear to indicate the severity of spinal cord compression and clinical recovery after decompression surgery, so spondylotic myelopathy may partly be predicted preoperatively by using ADC values.

Thoracic chordoma: review and role of FDG-PET.

Chordoma is an uncommon primary bone tumor and the thoracic spine is the least common of all sites for a chordoma. It may recur despite slow-growing nature. Precise literature review will be performed and possible use of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) for detection of both primary and recurrent diagnosis will be discussed. This article presents the case of a 73-year-old male patient who complained of back pain. Magnetic resonance (MR) imaging, computed tomography (CT) and FDG-PET demonstrated thoracic lesion and biopsy revealed chordoma. The patient was operated on and histological findings showed the tumor was chondroid chordoma. He suffered recurrence after 7 months by FDG-PET. He received 6,000 rads radiation therapy and is neurological free but, suffered backache 15 months after initial diagnosis. Only 12 cases including this case were reported precisely and this is the first report of FDG-PET for both initial and recurrent diagnosis of chordoma.

Decreased diameter of the optic nerve sheath associated with CSF hypovolemia.

The subarachnoid space around the optic nerve can be detected by fat-saturated T2-weighted MR imaging of the orbit, and dilation of this space reflects increased intracranial pressure. We examined 3 patients with CSF hypovolemia with MR imaging of the orbit and measured the optic nerve sheath diameter before and after treatment. We showed that the subarachnoid space is decreased in patients with CSF hypovolemia and the usefulness of this finding.

Diffusion Tensor Imaging and 3D Tractography of the Cervical Spinal Cord Using the ECG-Gated Line-scan Technique. A Feasibility Study.

Diffusion tensor (DT) magnetic resonance (MR) imaging in addition to conventional MR images provide valuable information on the brain. This study compared line scan DT imaging with and without the ECG-gating technique to estimate clinical usefulness of the line scan diffusion tensor image (LSDTI) with ECG-gating in evaluating spinal cord diseases in vivo. First, five healthy volunteers participated in the comparison study. LSDWI was performed in three to five sagittal sections with a pulsed-field-gradient diffusion preparation pulse employing two different b-values (0 and 700 s/mm(2)) along six directions. Apparent diffusion coefficient (ADC) maps and fractional anisotropy (FA) were calculated and three-dimensional tract reconstruction and color schemes of the spinal cord were obtained. Image quality and the acquisition time of each LSDTI were compared. Second, LSDTI with ECG-gating was performed in eighteen patients with cervical spinal cord disorders and evaluated by two neuroradiologists. Images with the ECG-gated technique were all superior to those without ECG-gating. Mean extended time for LSDTI with ECG-gating was approximately two minutes. In clinical use, the ADC and FA of spinal cord in patients with cervical spondylotic myelopathy statically changed. Moreover, demonstration of fibers was correlated with clinical symptoms. ECG-gating technique is preferable to LSDTI. The ADC and FA measurements and 3D fiber tracking of LSDTI with ECG-gating are promising methods to estimate cervical spinal cord pathology in clinical use.

Duct-penetrating sign at MRCP: usefulness for differentiating inflammatory pancreatic mass from pancreatic carcinomas.

PURPOSE: To define the duct-penetrating sign at magnetic resonance (MR) cholangiopancreatography (MRCP) and to assess the usefulness of this sign for distinguishing an inflammatory pancreatic mass (IPM) from a conventional pancreatic carcinoma (CPC) compared with arterial phase computed tomography (hereafter, CT) and arterial phase MR imaging (hereafter, MR imaging). MATERIALS AND METHODS: MRCP, CT, and MR images were compared by means of receiver operating characteristic (ROC) analysis for 11 IPMs and 43 CPCs. With the MRCP images, a morphologic classification of the main pancreatic duct (MPD) was attempted for all lesions. On the basis of this classification and the enhancement patterns of a lesion, all readers graded the presence of IPM or CPC on a five-point scale for all images. RESULTS: On the MRCP images, the morphologic characteristics of the MPD were nonobstruction for IPM (28 of 33, 85%) and obstruction or irregular stenosis for CPC (124 of 129, 96%). At ROC analysis among all the techniques, MRCP images had the highest value (0.98) for significant areas under the ROC curve (CT, 0.84; MR, 0.76) (P <.001). For the duct-penetrating sign in the broad sense (nonobstructed MPD) and the sign in the narrow sense (only normal MPD), the sensitivity, specificity, and accuracy for diagnosis of IPM were 85%, 96%, and 94%, respectively, and 36%, 100%, and 87%, respectively. CONCLUSION: The duct-penetrating sign on MRCP images was more helpful to distinguish IPM from CPC than were the enhancement patterns on CT and MR images.

Effect of concurrent intra-arterial infusion of platinum drugs for patients with stage III or IV uterine cervical cancer treated with radical radiation therapy.

PURPOSE: The purpose of this study was to explore the effect of concurrent intra-arterial infusion of platinum drugs in patients with stage III or IV uterine cervical cancer treated with radical radiation therapy. PATIENTS AND METHODS: Thirty-three patients with advanced (stage IIIA, 2; IIIB, 28; IVA, 3) uterine cervical squamous cell carcinoma were randomized into a concurrent intra-arterial infusion of platinum drugs with radiation therapy (IAPRT) group (18 patients) and a radiation therapy alone group (15 patients). After altering intrapelvic blood flow by embolization of the superior and inferior gluteal arteries under pelvic angiography, intra-arterial infusion of platinum drug through catheters inserted into both internal iliac arteries was performed concurrently with radiation therapy. One-shot infusion of cisplatin (100 mg/m2) twice with a 2- to 3-week interval was performed in eight patients, weekly infusion of carboplatin (100 mg/m2) via a reservoir five to six times was performed in four patients, and daily shot of cisplatin (10 mg/body) or 21 days via a reservoir was performed in six patients. Radiation therapy consisted of external-beam irradiation of 50 Gy/25 fractions/5 weeks for the whole pelvis with midline block after 30 Gy and intracavitary high-dose-rate brachytherapy using tandem and ovoids of 24 Gy/4 fractions/4 weeks to point A. RESULTS: The local complete response rate of the IAPRT group was 94% and was significantly higher than that of the radiation therapy group (67%). There were no significant differences in local response in the three drug delivery methods. Two- and 5-year overall survival rates were 54.5% and 44.4% in the IAPRT group, and 74.5% and 50.0% in the radiation therapy group, respectively. There was no significant difference between the two groups. In the IAPRT group, grade 3 or 4 acute bowel complications were seen in 33% of patients, grade 3 or 4 late bowel complications were seen 44%, and grade 3 or 4 myelosuppression was seen in 33%, and these complications were seen more in the IAPRT group than in the radiation therapy group and caused death in some patients. CONCLUSIONS: IAPRT had a better local response than radiation therapy but showed no proof of control over recurrence and had a poorer survival than radiation therapy. There were many local recurrences and distant metastases, contrary to the better first response of the IAPRT group over the radiation therapy group. Complications of the IAPRT group were very severe and made the patient's performance status and prognosis worse than in the radiation therapy group. We need to design some methods to decrease these complications to make use of the good local response acquired with IAPRT. Furthermore, we should re-examine the indication of IAPRT in patients with a large tumor because local recurrence and distant metastasis would be inevitable.

Two-dimensional thick-slice MR digital subtraction angiography for assessment of cerebrovascular occlusive diseases.

Although spatial resolution of current MR angiography is excellent, temporal resolution has remained unsatisfactory. We evaluated clinical applicability of 2D thick-slice, contrast-enhanced subtraction MR angiography (2D-MR digital subtraction angiography) with sub-second temporal resolution in cerebrovascular occlusive diseases. Twenty-five patients with cerebrovascular occlusive diseases (8 moyamoya diseases, 10 proximal internal carotid occlusions, and 2 sinus thromboses ) were studied with a 1.5-T MR unit. The MR digital subtraction angiography (MRDSA) was performed per 0.97 s continuously just after a bolus injection of 15 ml of gadolinium chelates up to 40 s in sagittal (covering hemisphere) or coronal planes. Subtraction images were generated at a workstation. We evaluated imaging quality and hemodynamic information of MRDSA in comparison with those of routine MR imaging, non-contrast MR angiography, and X-ray intra-arterial DSA. Major cerebral arteries, all of the venous sinuses, and most tributaries were clearly visualized with 2D MRDSA. Also, pure arterial phases were obtained in all cases. The MRDSA technique demonstrated prolonged circulation in sinus thromboses, distal patent lumen of proximal occlusion, and some collateral circulation. Such hemodynamic information was comparable to that of intra-arterial DSA. Two-dimensional thick-slice MRDSA with high temporal resolution has a unique ability to demonstrate cerebral hemodynamics equivalent to that of intra-arterial DSA and may play an important role for evaluation of cerebrovascular occlusive diseases.

[Application of MR-guided intravascular procedures by passive tracking utilizing the magnetic susceptibility effect: a preliminary report].

In MR-guided intravascular procedures, the position of catheters must be confirmed on near-real-time MR images. One way of monitoring this is by passive tracking utilizing the magnetic susceptibility effect. A catheter with a stainless steel braid had suitable visibility when tracked by magnetic susceptibility on fast GRE images, although the direction of the static magnetic field affected the apparent width of the catheter. Passive tracking with a 1.5T MRI unit was performed in a patient at one image/2 seconds with fast GRE. The catheter could be introduced to the SMA and celiac artery from the aorta with passive tracking.

Structure and function of the cytoskeleton in heliozoa: 2. Measurement of the force of rapid axopodial contraction in Echinosphaerium.

The large heliozoan Echinosphaerium extends a number of needle-like axopodia by which it captures food organisms. Every axopodium contains a bundle of several hundreds of axonemal microtubules as a cytoskeletal element. When the tip of a poly-L-lysine-coated glass micro-needle came into contact with the distal part of an axopodium, a rapid axopodial contraction (2.6 mm/s) occurred with a concomitant bending of the needle toward the cell body. In this report, we measured the force of the axopodial contraction by utilizing the relation between force and bending displacement of the micro-needle, and examined a possibility that the axopodial contraction is ascribed to the axopodial tension (surface tension and/or cytoplasmic elasticity) that is developed as a result of microtubule degradation. The force of the axopodial contraction was estimated in the order of 10(-9) N. Treatment with 10 mM colchicine induced disassembly of the axopodial microtubules and a resulting slow retraction of the axopodia (0.1 µm/s) occurred. The force of the slow retraction was also measured by the same procedure to estimate the axopodial tension, and was in the order of 10(-11) N. It was thus demonstrated that the motive force for axopodial contraction cannot be explained as an axopodial tension generated as a result of disassembly of the microtubules.

Rupture of pararenal pseudocyst in a patient with Down's syndrome.

A rare case of Down's syndrome with spontaneous rupture of a pararenal pseudocyst has been reported. The rupture of the pararenal pseudocyst was treated nonsurgically. The presence of this cyst in conjunction with Down's syndrome may be due, in part, to muscular hypotonia.

C7 deficiency and persistent haematuria.

A 14-year-old boy had persistent haematuria along with complete C7 deficiency. No significant changes in glomeruli and tubules were found in a renal biopsy specimen by light microscopy and immunofluorescence gave negative results for immune deposits. Electron microscopic examination demonstrated an attenuation of the glomerular capillary basement membrane without lamination and a diagnosis of thin basement membrane disease was made. It would be difficult to conclude that patients with C7 deficiency were predisposed to develop glomerulonephritis caused by immunologic aberrations. A family study failed to provide evidence of an association of C7 deficiency and thin basement membrane disease.