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Prolongation of the T2 relaxation time, an increase in T2-weighted signal intensity (T2-SI), and a decrease in the apparent diffusion coefficient (ADC) calculated from diffusion-weighted images (DWI) on magnetic resonance imaging (MRI) are conventional indicators of the vasogenic (interstitial) or cytotoxic (cellular) cerebral edema that develops after ischemic stroke. However, these parameters obtained on stroke imaging have not given us a precise threshold at which we can determine the viability or vulnerability of the tissue, allowing us to decide on an intervention that will help reversible tissue in the acute phase. Here, we introduce a new indicator-the essential diffusion coefficient or EDC, calculated from the T2-SI and ADC-that permits detection of irreversible brain damage after induction of experimental, focal cerebral ischemia. Our three-vessel occlusion (3-VO) method (Yang et al. Eur Neurol 71:4-18, 2014) was applied to investigate early changes on 7-T MRI. In the 3-VO model, which targets only a part of the cortex, animals seldom die at least within 24 h. The T2-SI and the ADC value were monitored, starting at 60 min after reperfusion, and every 30-60 min, for 10 h after the induction of focal ischemia. The region of interest (ROI) was set in each of the following: (1) the ischemic core (the dead zone); (2) the medial border area (the dying/dead mixed zone, including the ischemic penumbra); (3) the lateral border area (the surviving zone after the ischemic stress, where the rCBF is above the threshold for death); and (4) The intact area (outside the ischemic zone). The diagnosis was made by histological analysis performed 24 h after reperfusion. Significant increases in the T2-SI were observed, in ROI-1 at 1 h, in ROI-2 at 2.5 h, and in ROI-3 at 4 h post-reperfusion (1.10, 1.11, or 1.11; > 1.10, respectively, p < 0.001). Significant reductions in the ADC were also observed in ROI-1, ROI-2, and ROI-3, at 1 h post-reperfusion (0.55, 0.52, or 0.58; < 0.60, respectively, p < 0.001), indicating that both types of cerebral edema develop simultaneously in the acute phase. In the EDC analysis, from 5.0 h post-reperfusion, the value in the dying/dead zone (ROI-1 and ROI-2) was consistently reduced to < 50%, showing repeated, significant differences from the value in the surviving zone (ROI-3). A reduction in the EDC to below 50% indicated irreversible tissue damage, with transformation to cerebral infarction. We could detect a sign of cerebral infarction (initial necrosis-like irreversible lesion) as early as 5.25 h after the onset of ischemia. Although the biological time that depends on the body weight must be different between mice and humans, the earliest irreversible tissue damage or tissue destruction (to have achieved the risk of hemorrhagic transformation) that progressed after invisible or silent cell death in the ultra-acute phase, seems to occur at a similar time point.

Background Context: There is little information on the relationship between magnetic resonance imaging (MRI) T2-weighted high signal change (T2HSC) in the spinal cord and surgical outcome for cervical myelopathy. We therefore examined whether T2HSC regression at 1 year postoperatively reflected a 5-year prognosis after adjustment using propensity scores for potential confounding variables, which have been a disadvantage of earlier observational studies., Purpose: The objective of this study was to clarify the usefulness of MRI signal changes for the prediction of midterm surgical outcome in patients with cervical myelopathy., Study Design/setting: This is a retrospective cohort study., Patient Sample: We recruited 137 patients with cervical myelopathy who had undergone surgery between 2007 and 2012 at a median age of 69 years (range: 39-87 years)., Outcome Measures: The outcome measures were the recovery rates of the Japanese Orthopaedic Association (JOA) scores and the visual analog scale (VAS) scores for complaints at several body regions., Materials and Methods: The subjects were divided according to the spinal MRI results at 1 year post surgery into the MRI regression group (Reg+ group, 37 cases) with fading of T2HSC, or the non-regression group (Reg- group, 100 cases) with either no change or an enlargement of T2HSC. The recovery rates of JOA scores from 1 to 5 years postoperatively along with the 5-year postoperative VAS scores were compared between the groups using t test. Outcome scores were adjusted for age, sex, diagnosis, symptom duration, and preoperative JOA score by the inverse probability weighting method using propensity scores., Results: The mean recovery rates in the Reg- group were 35.1%, 34.6%, 27.6%, 28.0%, and 30.1% from 1 to 5 years post surgery, respectively, whereas those in the Reg+ group were 52.0%, 52.0%, 51.1%, 49.0%, and 50.1%, respectively. The recovery rates in the Reg+ group were significantly higher at all observation points. At 5 years postoperatively, the VAS score for pain or numbnessin the arms or hands of the patients in the Reg+ group (24.7 mm) was significantly milder than that of the patients in the Reg- group (42.2 mm)., Conclusions: Spinal T2HSC improvement at 1 year postoperatively may predict a favorable recovery until up to 5 years after surgery., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Study Design: A retrospective analysis., Objective: To evaluate the association between early postoperative dural sac cross-sectional area (DCSA) and radicular pain., Summary of Background Data: The correlation between postoperative magnetic resonance imaging (MRI) findings and postoperative neurological symptoms after lumbar decompression surgery is controversial., Methods: This study included 115 patients who underwent lumbar decompression surgery followed by MRI within 7 days postoperatively. There were 46 patients with early postoperative radicular pain, regardless of whether the pain was mild or similar to that before surgery. The intervertebral level with the smallest DCSA was identified on MRI and compared preoperatively and postoperatively. Risk factors for postoperative radicular pain were determined using univariate and multivariate analyses. Subanalysis according to absence/presence of a residual suction drain also was performed., Results: Multivariate regression analysis showed that smaller postoperative DCSA was significantly associated with early postoperative radicular pain (per -10 mm; odds ratio, 1.26). The best cutoff value for radicular pain was early postoperative DCSA of 67.7 mm. Even with a cutoff value of <70 mm, sensitivity and specificity are 74.3% and 75.0%, respectively. Early postoperative DCSA was significantly larger before suction drain removal than after (119.7±10.1 vs. 93.9±5.4 mm)., Conclusions: Smaller DCSA in the early postoperative period was associated with radicular pain after lumbar decompression surgery. The best cutoff value for postoperative radicular pain was 67.7 mm. Absence of a suction drain at the time of early postoperative MRI was related to smaller DCSA.

OBJECTIVE Transient neurological symptoms are frequently observed during the early postoperative period after direct bypass surgery for moyamoya disease. Abnormal signal changes in the cerebral cortex can be seen in postoperative MR images. The purpose of this study was to reveal the radiological features of the "cortical hyperintensity belt (CHB) sign" in postoperative FLAIR images and to verify its relationship to transient neurological events (TNEs) and regional cerebral blood flow (rCBF). METHODS A total of 141 hemispheres in 107 consecutive patients with moyamoya disease who had undergone direct bypass surgery were analyzed. In all cases, FLAIR images were obtained during postoperative days (PODs) 1-3 and during the chronic period (3.2 ± 1.13 months after surgery). The CHB sign was defined as an intraparenchymal high-intensity signal within the cortex of the surgically treated hemisphere with no infarction or hemorrhage present. The territory of the middle cerebral artery was divided into anterior and posterior parts, with the extent of the CHB sign in each part scored as 0 for none; 1 for presence in less than half of the part; and 2 for presence in more than half of the part. The sum of these scores provided the CHB score (0-4). TNEs were defined as reversible neurological deficits detected both objectively and subjectively. The rCBF was measured with SPECT using N-isopropyl-p-[ 123 I]iodoamphetamine before surgery and during PODs 1-3. The rCBF increase ratio was calculated by comparing the pre- and postoperative count activity. RESULTS Cortical hyperintensity belt signs were detected in 112 cases (79.4%) and all disappeared during the chronic period. Although all bypass grafts were anastomosed to the anterior part of the middle cerebral artery territory, CHB signs were much more pronounced in the posterior part (p < 0.0001). TNEs were observed in 86 cases (61.0%). Patients with TNEs showed significantly higher CHB scores than those without (2.31 ± 0.13 vs 1.24 ± 0.16, p < 0.0001). The CHB score, on the other hand, showed no relationship with the rCBF increase ratio (p = 0.775). In addition, the rCBF increase ratio did not differ between those patients with TNEs and those without (1.15 ± 0.033 vs 1.16 ± 0.037, p = 0.978). CONCLUSIONS The findings strongly suggest that the presence of the CHB sign during PODs 1-3 can be a predictor of TNEs after bypass surgery for moyamoya disease. On the other hand, presence of this sign appears to have no direct relationship with the postoperative local hyperperfusion phenomenon. Vasogenic edema can be hypothesized as the pathophysiology of the CHB sign, because the sign was transient and never accompanied by infarction in the present series.

Object: The purpose of the present study was to investigate the association between carotid artery (CA) expansive remodeling (ER) and symptoms of cerebral ischemia., Methods: One hundred twenty-two consecutive CAs scheduled for CA endarterectomy (CEA) or CA stent placement (CAS) were retrospectively studied. After excluding 22 CAs (2 were contraindicated for MRI, 8 had near-occlusion, 6 had poor image quality, and 6 had restenosis after CEA or CAS), there were 100 CAs (100 patients) included in the final analysis. The study included 50 symptomatic patients (mean age 73.6 ± 8.9 years, 6 women, mean stenosis 68.5% ± 21.3%) and 50 asymptomatic patients (mean age 72.0 ± 5.9 years, 5 women, mean stenosis 79.4% ± 8.85%). Expansive remodeling was defined as enlargement of the internal carotid artery (ICA) with outward plaque growth. The ER ratio was calculated by dividing the maximum distance between the lumen and the outer borders of the plaque perpendicular to the axis of the ICA by the maximal luminal diameter of the distal ICA at a region unaffected by atherosclerosis using long-axis, high-resolution MRI., Results: The ER ratio of the atherosclerotic CA was significantly greater than that of normal physiological expansion (carotid bulb; p < 0.01). The ER ratio of symptomatic CA stenosis (median 1.94, interquartile range [IQR] 1.58-2.23) was significantly greater than that of asymptomatic CA stenosis (median 1.52, IQR 1.34-1.81; p = 0.0001). When the cutoff value of the ER ratio was set to 1.88, the sensitivity and specificity to detect symptoms were 0.6 and 0.78, respectively. The ER ratio of symptomatic patients was consistently high regardless of the degree of stenosis., Conclusions: There was a significant correlation between ER ratio and ischemic symptoms. The ER ratio might be a potential indicator of vulnerable plaque, which requires further validation by prospective observational study of asymptomatic patients.

Background: Central neurocytoma was initially believed to be benign tumor type, although atypical cases with more aggressive behavior have been reported. Preoperative estimation for proliferating activity of central neurocytoma is one of the most important considerations for determining tumor management., Purpose: To investigate predictive values of image characteristics and quantitative measurements of minimum apparent diffusion coefficient (ADCmin) and maximum standardized uptake value (SUVmax) for proliferative activity of central neurocytoma measured by MIB-1 labeling index (LI)., Material and Methods: Twelve cases of central neurocytoma including one recurrence from January 2001 to December 2011 were included. Preoperative scans were conducted in 11, nine, and five patients for computed tomography (CT), diffusion-weighted imaging (DWI), and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET), respectively, and ADCmin and SUVmax of the tumors were measured. Image characteristics were investigated using CT, T2-weighted (T2W) imaging and contrast-enhanced T1-weighted (T1W) imaging, and their differences were examined using the Fisher's exact test between cases with MIB-1 LI below and above 2%, which is recognized as typical and atypical central neurocytoma, respectively. Correlational analysis was conducted for ADCmin and SUVmax with MIB-1 LI. A P value <0.05 was considered significant., Results: Morphological appearances had large variety, and there was no significant correlation with MIB-1 LI except a tendency that strong enhancement was observed in central neurocytomas with higher MIB-1 LI (P = 0.061). High linearity with MIB-1 LI was observed in ADCmin and SUVmax (r = -0.91 and 0.74, respectively), but only ADCmin was statistically significant (P = 0.0006)., Conclusion: Central neurocytoma had a wide variety of image appearance, and assessment of proliferative potential was considered difficult only by morphological aspects. ADCmin was recognized as a potential marker for differentiation of atypical central neurocytomas from the typical ones., (© The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Objectives: To evaluate the validity of 3D dynamic pituitary MR imaging with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), with special emphasis on demarcation of pituitary posterior lobe and stalk., Methods: Participants comprised 32 patients who underwent dynamic pituitary MR imaging due to pituitary or parasellar lesions. 3D dynamic MR with CAIPIRINHA was performed at 3T with 20-s-interval, precontrast, 1st to 5th dynamic images. Normalized values and enhanced ratios (dynamic postcontrast image values divided by precontrast ones) were compared between 3D and 2D dynamic MR imaging for patients with visual identification of posterior lobe and stalk., Results: In 3D, stalk was identified in 29 patients and unidentified in 3, and posterior lobe was identified in 28 and unidentified in 4. In 2D, stalk was identified in 26 patients and unidentified in 6 patients, and posterior lobe was identified in 15 and unidentified in 17. Normalized values of pituitary posterior lobe and stalk were higher in 3D than 2D (P<0.001). No significant difference in enhancement ratio was seen between 3D and 2D., Conclusions: 3D dynamic pituitary MR provided better identification and higher normalized values of pituitary posterior lobe and stalk than 2D., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Introduction: Quantitative values of CT attenuation, apparent diffusion coefficient (ADC), and standardized uptake value (SUV) were investigated for differentiation between pineal parenchymal tumors (PPTs) and germinomas. Differences in age, sex, and calcification pattern were also evaluated., Methods: Twenty-three patients with PPTs and germinomas in 20 years were retrospectively enrolled under the approval of the institutional review board. CT attenuation, ADC, and SUV (20, 13, and 10 patients, respectively) were statistically compared between the two tumors. Differences in sex and patterns of calcification ("exploded" or "engulfed") were also examined. Mean patient ages were compared among three groups of pineoblastoma, pineal parenchymal tumor of intermediate differentiation, (PPTID) and pineocytoma and germinoma., Results: None of the quantitative values of CT attenuation, ADC, and SUV showed significant differences between PPTs and germinomas (p > .05). However, there was a significant difference in age (p < .05) among the three groups of pineoblastoma (mean age ± standard deviation 7.0 ± 8.7 years), PPTID, and pineocytoma (53.7 ± 11.4 years) and germinoma (19.1 ± 8.1 years). Sex also showed significant differences between PPTs and germinomas (p = .039). Exploded pattern of calcification was found in 9 of 11 PPT patients and engulfed pattern in 7 of 9 patients with germinomas. No reverse pattern was observed, and the patterns of calcification were considered highly specific of tumor types., Conclusions: None of the quantitative imaging values could differentiate PPTs from germinomas. Age, sex, and calcification patterns were confirmed useful in differentiating these tumors to some degree.

Objective: We qualitatively evaluated the differences among susceptibility-weighted (SWI), magnitude (MAG), and high pass filtered phase (PHA) images in depicting interlobar differences in the appearance of the signal of the corticomedullary junction (CMJ). We conducted quantitative evaluation to validate the qualitative results., Materials and Methods: We obtained SWI images from 25 preoperative brain tumor patients (12 men, 13 women, aged 19 to 82 years, mean, 52 years). Two trained neuroradiologists evaluated MAG, PHA, and SWI images. Qualitative evaluation of the CMJ signal and quantitative calculation of the relative signal ratio (RSR) percentages between the CMJ and deep white matter (WM) were conducted at 3 different slice levels of the brain independently for 4 different lobes (frontal, parietal, temporal, and occipital) and compared among MAG, PHA, and SWI. The extent of the area of the CMJ signal was graded on a 4-point scale (Grade 3, >75%; Grade 2, 50 to 75%; Grade 1, 25 to 50%; Grade 0, <25%). Data were statistically analyzed using a nonparametric Friedman test., Results: The Kappa coefficients between the qualitative and quantitative grades were 0.002 for MAG, 0.0047 for PHA, and 0.050 for SWI. Qualitatively, on the PHA images and SWI, grades of the occipital lobes were significantly higher than those of the other lobes (P < 0.005). Quantitatively, PHA images showed statistically significant interlobar differences in RSR percentage values of the CMJ (P = 0.025)., Conclusion: Qualitatively, the appearance of the CMJ differed significantly among the different lobes of the brain on SWI and underlying PHA images but not on MAG images. Quantitatively, only PHA images showed significant interlobar differences in the RSR. PHA images are most sensitive to the CMJ signal contrast due to local paramagnetic iron content.

A 44-year-old man presented with a 12-day history of severe non-throbbing headache. He showed no physical abnormality but obesity. On day 12, ring-shaped low intensity lesions inside straight sinus were revealed on T2*-weighted MRI image (T2*WI). On the following day (day 13), he was found unresponsive at home, and ambulated with disturbed consciousness. FLAIR and diffusion-weighted MRI image disclosed high intensity signals in bilateral thalamus which were postulated as vasogenic edema. MR venography and conventional cerebral angiography showed an absence of flow in inferior sagittal sinus, vein of Galen, and straight sinus. These findings confirmed the diagnosis of cerebral venous thrombosis (CVT). Anticoagulant treatment was introduced and his consciousness level was gradually improved. On day 43, he was discharged with no neurological sequelae. A delay of correct diagnosis and treatment with CVT can lead to devastating disability or even to death. An early diagnosis of CVT is often dismissed owing to the nonspecific symptoms such as headache and nausea. Recent reports described high sensitivity of T2*WI for detecting CVT. Alterations in blood flow and oxyhemoglobin reduced products, deoxyhemoglobin, in thrombosed veins often produce the magnetic susceptibility on T2*WI. A detection of ring-shaped low intensity lesions within venous sinus on T2*WI were quite rare, and the signal changes of these sinus lesions were successfully visualized by chronological T2*WI. Taken together, our case implies that T2*WI is the powerful tool for the early detection of CVT, even before the critical symptoms might happen.

Introduction: It is important to have information on cavernous sinus extension and bony destruction in pituitary macroadenomas before surgery, but magnetic resonance (MR) imaging cannot always depict them. In the present study we sought to determine whether multidetector-row computed tomography (MDCT) could provide preoperative information in addition to that provided by MR imaging in pituitary macroadenoma., Methods: The subjects comprised 33 consecutive patients (15 women, 18 men; mean age 50 years) with surgically proven macroadenoma. For MDCT, using the soft-tissue window and bone window, three orthogonal multiplanar reconstruction images were generated from venous-phase contrast-enhanced 0.5-mm isotropic voxel data. MDCT and MR images were evaluated with regard to: (1) clarity of tumor margins; (2) identification of the normal pituitary gland; (3) identification of erosion or destruction of the sellar floor; and (4) visualization of the adjacent optic pathways., Results: MDCT more clearly demonstrated the lateral tumor margin than MR imaging (P = 0.002). No significant differences in visualization of the normal pituitary gland were noted between MDCT and dynamic MR imaging (P = 0.7). MDCT more clearly demonstrated sellar floor erosion or destruction at the sphenoid sinus than MR imaging (P < 0.001). MR imaging was superior to MDCT for visualizing the adjacent optic pathways (P < 0.001)., Conclusion: MDCT is superior to MR imaging for assessing lateral tumor margin and the sellar floor at the sphenoid sinus. MDCT offers useful preoperative information in addition to that obtained from MR imaging.

Liliequist's membrane is an arachnoid structure well-known to neurosurgeons. However, the importance of this membrane had been lost until the development of endoscopic third ventriculostomy (ETV). ETV is superior in its minimal invasiveness, but in some subgroups of hydrocephalus, the effectiveness of ETV may be reduced. Liliequist's membrane may block the cerebrospinal fluid (CSF) flow from the defect of the third ventricle floor, which may cause failure of ETV. Liliequist's membrane can be visualized on magnetic resonance (MR) imaging in normal healthy individuals, however, its visibility is different among individuals. CSF artifacts exist to varying degrees, but do not impede visualization of Liliequist's membrane in most subjects. Since Liliequist's membrane is a cisternal structure, the three-dimensional (3D) constructive interference in steady state (CISS) sequence is useful. The outcome of ETV could be predicted with MR imaging findings of Liliequist's membrane in a patient with obstructive hydrocephalus. High-field (> or =3 Tesla) MR imaging of Liliequist's membrane also offers superior resolution and is expected to provide additional information about Liliequist's membrane.

Background and Purpose: In patients with macroadenoma, posterior pituitary high signal (PPHS) on T1-weighted magnetic resonance (MR) imaging is sometimes observed in an ectopic location. The present study compared incidences of ectopic PPHS before and after macroadenoma surgery using MR imaging, including dynamic MR imaging to ascertain whether this ectopic change is irreversible., Materials and Methods: MR imaging was performed preoperatively in 111 cases of macroadenoma, and then repeated more than 1-year postoperatively in 47 patients. Enhancement of PPHS was assessed using dynamic MR imaging. Areas of enhanced hyperintensity were considered true PPHS, and the relationship between presence and location of true PPHS and adenoma volume was analyzed. Moreover, changes in the presence and location of true PPHS were ascertained among the patients who underwent postoperative follow-up MR imaging., Results: Preoperatively, PPHS was seen only in the normal location in 29 patients (Group A: 26.1%). High signal was detected only in an ectopic location in 58 patients, and early enhancement of this ectopic high signal was confirmed by dynamic MR imaging in 56 patients (Group B: 50.5%). No PPHS was observed in 24 patients (Group C: 21.6%). Adenoma volume was significantly greater for Group B than for Group A (p<0.001). Among the Group B patients who underwent MR imaging postoperatively (n=31), the location of PPHS was not changed, except for two patients in whom PPHS was absent. Postoperatively, PPHS was not observed in the normal location in any patient in the Group B., Conclusions: Greater volume of adenoma is associated with a higher incidence of ectopic PPHS, and the ectopic change is irreversible.

Objective: Magnetic resonance (MR) imaging and computed tomography (CT) findings of neurohypophyseal germinoma have not previously been described in detail. The purpose of the present study was to establish the spectrum of MR imaging and CT findings in neurohypophyseal germinomas., Materials and Methods: MR and CT images of 13 consecutive patients (seven males, six females; mean age: 15 years; range: 6-31 years) with neurohypophyseal germinoma were retrospectively analyzed. The diagnosis had been made either histologically (n=8) or clinically according to established criteria (n=5). All patients had been examined using MR imaging and CT before treatment., Results: On MR imaging, infundibular thickening (up to 16 mm) was observed in all 13 cases. Hyperintensity of the posterior pituitary on T1-weighted image was absent in all 13 cases (100%) and 12 of the 13 displayed central diabetes insipidus. Ten germinomas (77%) were isointense to cerebral cortex on T1-weighted image, but variable intensities were exhibited on T2-weighted image. MR images revealed intratumoral cysts in six cases (46%), most of which demonstrated intra-third ventricular extension. Eleven of the 13 cases (85%) revealed hyperdense solid components on unenhanced CT. Calcification was absent in all cases (100%)., Conclusion: Infundibular thickening, absence of the posterior pituitary high signal on T1-weighted image, lack of calcification and hyperdensity on unenhanced CT are common imaging features of neurohypophyseal germinoma.

Purpose: To evaluate the Liliequist membrane in healthy volunteers by using three-dimensional (3D) Fourier transformation constructive interference in steady state (CISS) magnetic resonance (MR) imaging., Materials and Methods: In 31 volunteers, the authors performed 3D CISS MR imaging. They divided the membrane into three segments: the sellar, diencephalic, and mesencephalic segments. MR images were evaluated to identify the segments, superior and inferior attachments, lateral border, and thickness of the Liliequist membrane., Results: Three-dimensional CISS MR imaging depicted the sellar, diencephalic, and mesencephalic segments of the Liliequist membrane in the sagittal plane in 25 (81%), 16 (52%), and five (16%) of the 31 subjects, respectively. Transverse MR imaging depicted these segments in 24 (77%), 10 (32%), and two (6%) subjects, respectively, and coronal MR imaging depicted them in 24 (77%), 12 (39%), and two (6%) subjects, respectively. Clear attachment of the membrane to the dorsum sellae was observed in 22 (88%) of 25 subjects in whom the sellar segment was identified. Clear attachment to the mamillary body was identified in eight (50%) of 16 subjects in whom the diencephalic segment was identified. The Liliequist membrane was attached to the oculomotor nerve on seven (14%) of 50 sides of the lateral border and to the arachnoid membrane around the oculomotor nerve on 28 (56%) sides. In the sagittal plane, the thickness of the membrane was less than one-half the thickness of the third ventricle floor in 22 (88%) of 25 subjects., Conclusion: The Liliequist membrane can be visualized by using 3D CISS MR sequences., (Copyright RSNA, 2003)

The most serious complication of neurovascular interventions is distal cerebral embolism. Diffusion-weighted MR imaging (DWI) appears to be the most sensitive technique for detecting early and small ischemic lesions. To evaluate the incidence and radiological features of embolic events associated with neuro-intervention, we applied DWI to screening for procedure-related ischemic lesions including silent embolisms. One hundred and thirty-seven patients who have received 154 neuro-interventional procedures were studied with DWI before and within 5 days after treatment. Imaging was performed, using single-shot echo-planar imaging with b value of 1000-1100 sec/mm2. DWI findings were classified into 5 groups by size and location of lesions: type 0 (n = 71), no lesions; I (n = 33), lesions in border-zone regions only; II (n = 9), lesions at perforator territories mainly; III (n = 29), small territorial lesions (< 5 mm); IV (n = 12), large territorial lesions (> or = 5 mm). DWI detected procedure-related lesions in 83 of 154 procedures (53.9%), 36 of which demonstrated new neurological symptoms during and/or after procedures. The parent artery occlusion for cerebral aneurysms had a higher incidence of symptomatic embolisms than other procedures. In 71 of 154 procedures (46.1%), DWI detected no lesions (type 0). Although type I was the most frequent pattern presented, it included few neurological symptoms. Type III often resulted in transient symptoms, and type II and IV tended to induce strokes. Because ischemic lesions detected by DWI were likely to arise in border-zone territories by parent artery occlusions, we considered that hypoperfusion as well as emboli were involved in the evolution of cerebral infarctions. Thus, DWI is a useful method to detect silent embolisms, and to determine the safety of neuro-intervention and the mechanism of embolic ischemia.

Purpose: To investigate the effects of a new remnant-preserving double-bundle anterior cruciate ligament reconstruction (ACLR) technique, focused on avoiding remnant damage and preserving continuity of remnants, on graft maturity using magnetic resonance imaging (MRI). Methods: A total of 169 patients were divided into three groups: 41 in the preservation group, 70 in the resection group, and 58 in the absent group. In the preservation group, rather than passing the graft through the remnant tissue, the graft was reconstructed such that the anteromedial and posterolateral bundles sandwiched the remnant to avoid damage to the remnant and maintain its continuity. Based on 1-year postoperative MRI, the grafts were divided into three regions: distal, middle, and proximal. The signal/noise quotient (SNQ) of each region of interest was calculated to evaluate the signal intensity of the graft and was compared among the three groups. Additionally, to identify factors influencing graft maturity, a multiple regression analysis was performed with SNQ as the dependent variable and patient demographics, bone morphology, and surgical factors as independent variables. Results: In a three-group comparison of mean SNQs, the distal region was 3.3 ± 3.4, 8.9 ± 8.3, and 9.0 ± 8.6 (p < 0.001), the middle region was 5.3 ± 3.7, 10.9 ± 11.1, and 11.3 ± 10.2 (p < 0.001), and the proximal region was 6.8 ± 4.5, 11.1 ± 8.8, and 11.7 ± 10.8 (p = 0.017), in order of the preservation, resection, and absent groups, respectively. That indicated that the remnant-preserving ACLR was more hypointense than ACLR with remnant resection or absent in all three regions. Multiple regression analysis showed that remnant preservation remained the relevant factor affecting SNQ of the graft at the distal and middle levels. Conclusion: The new remnant-preserving anatomic double-bundle ACLR had significantly better graft maturity, measured by SNQ on MRI, than the remnant resection and absent groups. The remnant procedure was the relevant factor affecting graft maturity. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Background. Previous studies have shown that intratumoral hemorrhage is a common finding in glioblastoma multiforme, but is rarely observed in primary central nervous system lymphoma. Our aim was to reevaluate whether intratumoral hemorrhage observed on T2-weighted imaging (T2WI) as gross intratumoral hemorrhage and on susceptibilityweighted imaging as intratumoral susceptibility signal can differentiate primary central nervous system lymphoma from glioblastoma multiforme.

• We often encounter cases with inconsistent between deep tendon reflex (DTR) findings and stenosis on cervical spine MRI. • We evaluated the surgical results of patients with CSM with inconsistent between DTR findings and cervical MRI findings. • We showed that unmatched CSM was present in 46% of the cases and postoperative clinical score is significantly inferior to among unmatched CSM patients. To evaluate the surgical results of patients with cervical spondylotic myelopathy (CSM) with inconsistency between deep tendon reflex findings and cervical magnetic resonance imaging (MRI) findings and to analyze the differences between patients with good and poor surgical outcomes. We evaluated 50 subjects with CSM (30 males, 20 females; mean age: 70.4 years) who underwent posterior surgery and were followed for at least 1 year postoperatively. Matched CSM was defined as a consistent preoperative neurological pattern determined by deep tendon reflex and cervical MRI T2-weighted high-signal intramedullary area or stenosis in the most cranial compression levels. A lack of consistency was classified as unmatched CSM. Recovery rate (RR) according to Japanese Orthopaedic Association (JOA) scoring preoperatively and at 1 year postoperatively were compared between the groups. The matched and unmatched CSM group included 27 subjects (13 males, 14 females; mean age: 68.2 years) and 23 subjects (17 males, 6 females; mean age: 72.8 years), respectively. RR was significantly higher in the matched CSM group (56.1 ± 3.7 % vs 36.8 ± 2.7 %; p = 0.002). Unmatched CSM was significantly associated with a lower RR independently of sex, patient age, surgical procedure, preoperative JOA score, diagnosis levels, and complication of diabetes. Postoperative JOA score RR was significantly diminished among unmatched CSM patients comprising of 46% of cases. Some patients with unmatched CSM had multiple levels of spinal canal stenosis, foraminal stenosis, and peripheral neuropathy, suggesting that surgical results were poorer than those of matched CSM. [ABSTRACT FROM AUTHOR]

The clinical significance of asymptomatic microbleeds in moyamoya disease remains unclear. The purpose of this study was to clarify the relationship between bypass surgery and the incidence of asymptomatic microbleeds. This retrospective study included 142 adult patients (mean age, 37.7 ± 13.5 years) with moyamoya disease, 36 of whom (25.3%) underwent bypass surgery in childhood. Hemorrhagic onset was diagnosed in 31 patients (21.8%). The incidence of microbleeds was evaluated on T2*-weighted or susceptibility-weighted imaging from 3-T magnetic resonance imaging. The patients were subsequently categorized into MBs (microbleeds) or non-MBs groups. Because previous microbleeds potentially lead to hemorrhage, the MBs group was defined as patients with radiographic evidence of bleeding, including asymptomatic microbleeds and/or hemorrhagic onset. The association of baseline characteristics was evaluated. Asymptomatic microbleeds were detected in 38 patients (26.8%). Of 31 patients with hemorrhagic onset, 18 had microbleeds, whereas 13 had no microbleeds. Therefore, 51 patients (35.9%) were classified into the MBs group. Bypass surgery in childhood (MBs, 7.8% vs. non-MBs, 35.2%; P < 0.01) and age (MBs, 42.9 ± 1.8 years vs. non-MBs, 34.7 ± 1.4 years; P < 0.01) were statistically significant factors associated with microbleeds, but only bypass surgery in childhood remained statistically significant after multivariable adjustment (odds ratio, 0.25; 95% confidence interval, 0.07–0.87; P = 0.03). This study shows the clinical significance of revascularization surgery in childhood associated with a low incidence of asymptomatic microbleeds in adult patients with moyamoya disease. This finding indicates that a newly established bypass can reduce hemodynamic overstress. [ABSTRACT FROM AUTHOR]

Compressed sensing (CS) reconstructions of under-sampled measurements generate missing data based on assumptions of image sparsity. Non-contrast time-of-flight MR angiography (TOF-MRA) is a good candidate for CS based acceleration, as MRA images feature bright trees of sparse vessels over a well-suppressed anatomical background signal. A short scan time derived from CS is beneficial for patients of moyamoya disease (MMD) because of the frequency of MR scans. The purpose of this study was to investigate the reliability of TOF-MRA with CS in the evaluation of MMD. Twenty-two patients were examined using TOF-MRA with CS (CS-TOF) and parallel imaging (PI-TOF). The acceleration factors were 3 (CS3) and 5 (CS5) for CS-TOF, and 3 (PI3) for PI-TOF. Two neuroradiologists evaluated the MMD grading according to stenosis/occlusion scores using the modified Houkin’s system, and the visibility of moyamoya vessels (MMVs) using a 3-point scale. Concordance was calculated with Cohen’s κ. The numbers of MMVs in the basal ganglia were compared using Bland-Altman analysis and Wilcoxon’s signed-rank tests. MRA scan times were 4:07, 3:53, and 2:42 for PI3, CS3, and CS5, respectively. CS-reconstruction completed within 10 minutes. MMD grading and MMV visibility scales showed excellent correlation (κ > .966). Although the number of MMVs was significantly higher in CS3 than in PI3 (p < .0001) and CS5 (p < .0001), Bland-Altman analysis showed a good agreement between PI3, CS3, and CS5. Compressed sensing can accelerate TOF-MRA with improved visualization of small collaterals in equivalent time (CS3) or equivalent results in a shorter scan time (CS5). [ABSTRACT FROM AUTHOR]

Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disease that causes abnormal enlargement of collateral pathways (moyamoya vessels) in the region of the basal ganglia and thalamus. Cerebral revascularization procedures remain the preferred treatment for patients with MMD, improving the compromised cerebral blood flow (CBF). However, voxel based analysis (VBA) of revascularization surgery for MMD based on data from pre- and postoperative data has not been established. The latest algorithm called as Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) has been introduced for VBA as the function of statistical parametric mapping (SPM8), and improved registration has been achieved by SPM8 with DARTEL. In this study, VBA was conducted to evaluate pre- and postoperative single photon emission computed tomography (SPECT) images for MMD by SPM8 with DARTEL algorithm, and the results were compared with those from SPM8 without DARTEL (a conventional method). Thirty-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery as the first surgery were included and all patients underwent pre- and postoperative 3D T1-weighted imaging and SPECT. Pre- and postoperative SPECT images were registered to 3D T1-weighted images, then VBA was conducted. Postoperative SPECT showed more statistically increased CBF areas in the bypassed side cerebral hemisphere by using SPM8 with DARTEL (58,989 voxels; P<0.001), and increased ratio of CBF after operation was less than 15%. Meanwhile, postoperative SPECT showed less CBF increased areas by SPM8 without DARTEL. In conclusion, VBA was conducted for patients with MMD, and SPM8 with DARTEL revealed that postoperative SPECT showed statistically significant CBF increases over a relatively large area and with at most 15% increase ratio. [ABSTRACT FROM AUTHOR]

Abstract: Background: In degenerative lumbar spinal disease with nerve root compression, the L5 and S1 nerve roots are the most often affected and the L3 nerve root is involved infrequently. The purpose of this study was to investigate the characteristics of L3 nerve root radiculopathy. Methods: Seventeen consecutive patients with L3 radiculopathy were treated. The symptomatic nerve roots were determined by the pain distribution, the neurologic findings, and selective nerve root injection. The clinical characteristics and outcomes of these patients were assessed retrospectively. Results: The average age was 76 years. The spinal diseases that were associated with L3 radiculopathy were lumbar canal stenosis in 6 patients, lumbar extraforaminal stenosis and lumbar disk herniation in 5 each, and lumbar canal stenosis with degenerative scoliosis in 1. The patients'' symptoms were thigh pain in 12 patients, and hip or knee pain in 5. Four patients were nonambulatory because of severe pain. Although a sensory disturbance was reported in 9 patients, motor weakness was present in 2. Selective nerve root injection was completely effective in 10 patients. Six had decompressive surgery and/or fusion followed by a favorable outcome. Four patients were misdiagnosed and received conservative treatment for hip and/or knee joint diseases. Conclusions: L3 radiculopathy was characterized by various lower limb pain and neurologic deficit. Selective nerve root injection was effective for most patients. In elderly patients who do not respond to treatment for hip and/or knee joint diseases, L3 nerve root radiculopathy should be considered as the cause of lower limb pain. [Copyright &y& Elsevier]

Antiphospholipid syndrome is characterized with arterial and venous thrombosis. In this article, a 38-year old man presented with headache and swelling of his left limb, which had lasted for 2 months. Duplex ultrasonography showed thrombosis of the left femoral vein. Cerebral magnetic resonance imaging also showed cerebral sinus thrombosis. Serological examination showed that antiphospholipid syndrome was the underlying disease condition in this patient. Despite adequate anticoagulant therapy, deep vein thrombosis and cerebral sinus thrombosis exacerbated, resulting in inferior vena cava occlusion, papilloedema, and abducent nerve paralysis. Optic canal decompression and cistern-peritoneal shunt operation were performed, following which his neurological symptoms were relieved. The occurrence of cerebral sinus thrombosis as initial presentation of antiphospholipid syndrome is extremely rare and remains a diagnostic challenge. Although the clinical presentation is highly variable, the diagnosis should be considered in patients with antiphospholipid syndrome presenting with recent unusual headaches. Improved diagnosis and treatment strategy may ultimately improve the clinical outcome of these patients. [ABSTRACT FROM AUTHOR]

Background Context: Osteoid osteoma of the thoracic spine is relatively uncommon and is often difficult to diagnose, especially when patients do not complain of pain.Purpose: This study aims to describe an unusual case of scoliosis caused by osteoid osteoma of the thoracic spine that was challenging to diagnose.Study Design/setting: A case report of a 12-year-old girl who presented with scoliosis caused by osteoid osteoma of the thoracic spine without apparent pain was carried out.Methods: Diagnosis of the lesion was made using computed tomography (CT) and magnetic resonance imaging as well as the Scoliosis Research Society-22 (SRS-22) patient-based questionnaire.Results: A preoperative CT myelogram revealed a mass lesion in the lamina of the 10th thoracic vertebra that was considered to be osteoid osteoma. This diagnosis was histologically confirmed following tumor excision. The patient's spinal deformity and SRS-22 scores were both improved at 5 months postoperatively.Conclusions: Osteoid osteoma of the thoracic spine may present as non-painful scoliosis. Tumor resection is effective. Clinicians should bear this uncommon lesion in mind during recommended CT examination before scoliosis surgery. [ABSTRACT FROM AUTHOR]

Background Context: Posterior spinal fusion with pedicle screws is commonly used for the treatment of adolescent idiopathic scoliosis (AIS). To reduce radiation exposure, methods other than computed tomography (CT) are desirable for preoperative determination of pedicle diameter.Purpose: Investigate the differences between magnetic resonance imaging (MRI) and CT measurements of pedicle diameter.Study Design: Cross-sectional research.Patient Sample: Twenty-one AIS Lenke type 1 patients (19 female and 2 males, mean age at surgery: 15.4 years) who underwent posterior spinal fusion between April 2009 and October 2019.Outcome Measures: Gap between CT and MRI pedicle diameters.Methods: The inner and outer diameters of the right and left pedicles from T1 to L3 were measured separately by two spine surgeons for statistical comparisons.Results: The respective minimum and maximum CT-MRI values were -3.7 mm and 4.7 mm for inner diameter and -4.6 mm and 5.3 mm for outer diameter. Regarding inter-examiner error, the probability of a 2 mm difference in measurement was less than 5% for both modalities. The probability of a 1 mm difference was also less than 5%, and that of a 3 mm or more difference was 2.1% for the inner diameter and 2.9% for the outer diameter. Whereas low body weight was significantly associated with measurement differences, pedicle laterality was not.Conclusions: MRI does not have the reliability to measure pedicle size in AIS patients at present. However, with advancements in image processing technology, the accuracy of pedicle size measurement by MRI may soon improve. [ABSTRACT FROM AUTHOR]

Study Design: Case report.Objective: We report here on an 18-month-old boy with brachytelephalangic chondrodysplasia punctata (BCDP), whose atlantoaxial instability was successfully managed with occipitocervical instrumented fusion (OCF) using screw and rod instrumentations.Summary Of Background Data: Recently, there have been a number of reports on BCDP with early onset of cervical myelopathy. Surgical OCF is a vital intervention to salvage affected individuals from the life-threatening morbidity. Despite recent advancement of instrumentation techniques, however, rigid OCF is technically demanding in very young children with small and fragile osseous elements. To our best knowledge, this is the first report on application of the instrumentation technique to a toddler patient with BCDP.Methods: A 16-month-old boy with BCDP presented with tetraplegia and swallow obstacle. Hypoplasia of the odontoid process and atlantoaxial instability were present in lateral radiographs. T2-weighted magnetic resonance (MR) images revealed a high signal region in the spinal cord at the C1-2 and C7-T1 levels. Cervical computed tomography (CT) showed that the pedicles and lateral masses in the cervical spine were small and immature, but the laminae were comparatively thick.Results: One week before surgery, the patient was fitted with a Halo-body jacket. We performed plate-rod placement with occipital cortical screws and C2/C3 interlaminar screws, and added an autogenous bone graft using the right 8 and 9 ribs. Rigid fixation of the occipito-cervical spine was completed successfully without major complications. Postoperative halo-body jacket immobilization was continued for 3 months, after which Aspen collar was fitted. CT confirmed occipitocervical bone fusion at 6 months after surgery. Mild clinical improvements in motor power of the affected muscles and swallowing were witnessed at 1 year postoperatively.Conclusion: Rigid fixation using screw, rod, and occipital plate instrumentation was successful in an 18-month-old toddler with BCDP and atlantoaxial instability. Bone fusion was achieved at postoperative 6 months.Level Of Evidence: 5. [ABSTRACT FROM AUTHOR]

Objective Hemangioblastomas remain a surgical challenge because of their arteriovenous malformation–like character. Recently, indocyanine green (ICG) videoangiography has been applied to neurosurgical vascular surgery. The aim of this study was to evaluate the usefulness of tumor blood flow imaging by intraoperative ICG videoangiography in surgery for hemangioblastomas. Methods Twenty intraoperative ICG videoangiography procedures were performed in 12 patients with hemangioblastomas. Seven lesions were located in the cerebellum, two lesions were in the medulla oblongata, and three lesions were in the spinal cord. Results Ten procedures were performed before or during dissection, and 10 procedures were performed after tumor resection. ICG videoangiography could provide dynamic images of blood flow in the tumor and its related vessels under surgical view. Interpretation of these dynamic images of tumor blood flow was useful for discrimination of transit feeders (feeders en passage) and also for estimation of unexposed feeders covered with brain parenchyma. Postresection ICG videoangiography could confirm complete tumor resection and normalized blood flow in surrounding vessels. Conclusions In surgery for hemangioblastomas, careful interpretation of dynamic ICG images can provide useful information on transit feeders and unexposed hidden vessels that cannot be directly visualized by ICG. [ABSTRACT FROM AUTHOR]