Loss of methylthioadenosine phosphorylase immunoreactivity correlates with poor prognosis and elevated uptake of 11C-methionine in IDH-mutant astrocytoma.

PURPOSE: The proximate localization of MTAP, which encodes methylthioadenosine phosphorylase, and CDKN2A/B on Chromosome 9q21 has allowed the loss of MTAP expression as a surrogate for homozygous deletion of CDKN2A/B. This study aimed to determine whether MTAP status correlates with clinical outcomes and 11C-methionine uptake in astrocytomas with IDH mutations. METHODS: We conducted immunohistochemistry for MTAP in 30 patients with astrocytoma, IDH-mutant who underwent 11C-methionine positron emission tomography scans prior to surgical resection. The tumor-to-normal (T/N) ratio of 11C-methionine uptake was calculated using the mean standardized uptake value (SUV) for tumor and normal brain tissues. Cox regression analysis was used for multivariate survival analysis. RESULTS: Among IDH-mutant astrocytomas, 26.7% (8/30) exhibited the loss of cytoplasmic MTAP expression, whereas 73.3% (22/30) tumors retained MTAP expression. The median progression-free survival (PFS) was significantly shorter in patients with MTAP loss than those with MTAP retention (1.88 years vs. 6.80 years, p = 0.003). The median overall survival (OS) was also shorter in patients with MTAP loss than in MTAP-retaining counterparts (5.23 years vs. 10.69 years, p = 0.019). Multivariate analysis identified MTAP status (hazard ratio (HR), 0.081) and extent of resection (HR, 0.104) as independent prognostic factors for PFS. Astrocytomas lacking cytoplasmic MTAP expression showed a significantly higher median T/N ratio for 11C-methionine uptake than tumors retaining MTAP (2.12 vs. 1.65, p = 0.012). CONCLUSION: Our study revealed that the loss of MTAP expression correlates with poor prognosis and an elevated T/N ratio of 11C-methionine uptake in astrocytoma, IDH-mutant.

Spontaneous occlusion of ruptured microaneurysm formed on postoperative transosseous anastomosis after indirect revascularization in a patient with moyamoya disease.

A 40-year-old female with a history of ischemic moyamoya disease treated with indirect revascularization at ages 12 and 25 years presented with a sudden severe headache. Imaging studies revealed focal parenchymal hemorrhage and acute subdural hematoma, confirming a microaneurysm formed on the postoperative transosseous vascular network as the source of bleeding. Conservative management was performed, and no hemorrhage recurred during the 6-month follow-up period. Interestingly, follow-up imaging revealed spontaneous occlusion of the microaneurysm. However, due to the rarity of this presentation, the efficacy of conservative treatment remains unclear. Further research on similar cases is warranted.

[Microvascular Decompression Surgery Using Exoscope(ORBEYE)].

Compared with an operative microscope, the ORBEYE has several advantages, including fatigue reduction for the operator in a relaxed and head-up natural position, infinite access, wide working space, and high educational value owing to the 3D images shared by everyone. Microvascular decompression surgery(MVDS)has similar advantages. Although operators need to learn surgical skills using different visual and surgical axes, in my personal experience, 10 cases of MVDS were practical for acquiring the skill in terms of operation time. Moreover, arranging proper ORBEYE settings in the operating room is essential for the assistants' accurate support.

T2-FLAIR mismatch sign correlates with 11C-methionine uptake in lower-grade diffuse gliomas.

PURPOSE: The T2-FLAIR mismatch sign is recognized as an imaging finding highly suggestive of IDH-mutant astrocytomas. This study was designed to determine whether the T2-FLAIR mismatch sign correlates with uptake of 11C-methionine in lower-grade gliomas. METHODS: We included 78 histopathologically verified lower-grade gliomas (grade 2: 31 cases, grade 3: 47 cases) in this study. 78 patients underwent 11C-methionine positron emission tomography (MET-PET) scans and magnetic resonance (MR) imaging scans prior to histological diagnosis. The tumor-to-normal ratio (T/N) of 11C-methionine uptake was calculated by dividing the maximum standardized uptake value (SUV) for the tumor by the mean SUV of the normal brain. MR imaging scans were evaluated for the presence of the T2-FLAIR mismatch sign by three independent reviewers. We compared molecular status, the T2-FLAIR mismatch sign and 11C-methionine uptake among patients with different lower-grade glioma molecular types. RESULTS: The 78 lower-grade gliomas were assigned to one of three molecular groups: Group A (IDH-mutant and 1p/19q non-codeleted, n = 22), Group O (IDH-mutant and 1p/19q codeleted, n = 20), and Group W (IDH wildtype, n = 36). T2-FLAIR mismatch was found in 16 cases (20.5%) that were comprised of 8 (36.4%), 0 (0%), 8 (22.2%) cases in the molecular group A, O and W, respectively. The median T/N ratio of MET-PET in tumors with T2-FLAIR mismatch was 1.50, which was significantly lower than that of tumors without T2-FLAIR mismatch (1.83, p < 0.001, Mann-Whitney U test). In the Groups A and W (excluding Group O), the median T/N ratio on MET-PET in groups A and W (but not group O) with T2-FLAIR mismatch was 1.50, which was significantly lower than that of tumors without T2-FLAIR mismatch (1.81, p = 0.002, Mann-Whitney U test). CONCLUSION: The T2-FLAIR mismatch sign correlated with lower 11C-methionine uptake in lower grade gliomas.

Changes in the clinical spectrum of pediatric moyamoya disease over 40 years.

OBJECTIVE: To investigate the chronological changes in the clinical presentation and long-term prognosis of pediatric-onset moyamoya disease in our institute over 40 years. METHODS: We evaluated 282 pediatric-onset (≤ 15 years old) moyamoya disease patients who visited our institute from 1981 to 2020 (divided into the former period, 1981-2000, and the latter period, 2001-2020). Differences in the clinical presentation and the long-term outcome were compared between the periods. Multivariate analysis was also performed to reveal the risk factors for poor long-term outcomes. RESULTS: Compared to the former period, the total number of patients, the onset age and both the number of patients with family history and relatively older patients without symptoms or with headache were greater in the latter period (p < 0.05). The number of patients with poor long-term outcomes was significantly lower in the latter period (24.9% vs. 6.7%, p < 0.01). Multivariate analysis revealed that stroke onset, late cerebrovascular events and postoperative complications were independent risk factors for poor long-term outcomes (odds ratio = 31.4, 40.8 and 5.4, respectively). CONCLUSIONS: Over the last 40 years, the number of pediatric moyamoya disease patients has increased, especially in relatively older patients with mild presentation and favorable long-term outcomes. In clinical studies, these chronological changes and the inclusion period of the participants need to be accounted for. Whether the increased diagnostic rate in the recent era has led to a decrease in late cerebrovascular events and favorable outcomes throughout life remains unknown and should be evaluated in the future.

Differences in cerebral blood flow measurement using arterial spin labeling MRI between patients with moyamoya disease and patients with arteriosclerotic cerebrovascular disease.

BACKGROUND: It is unclear whether the accuracy of arterial spin labeling (ASL) magnetic resonance imaging (MRI) is the same between moyamoya disease (MMD), which is known to have markedly elevated cerebral blood volume (CBV), and atherosclerotic intracranial arterial stenosis (AS), which has relatively less elevated CBV. PURPOSE: To investigate how the differences in hemodynamics affect measurement of ASL-cerebral blood flow (CBF) using ASL for patients with MMD and AS. MATERIAL AND METHODS: Fourteen MMD and ten AS patients were evaluated with ASL-MRI, magnetic resonance angiography (MRA), and 15O-gas positron emission computed tomography (PET). The regional CBF values of ASL using two post-labeling delays (PLDs; 1525 ms and 2525 ms) were compared with the PET-derived CBF, CBV, and mean transit time (MTT). Corresponding anterior circulation results were evaluated by flow territory map-based analysis. RESULTS: The correlation between the ASL-CBF values (2525 ms) and PET-CBF declined in the MMD group (r = 0.28; P < 0.01), while the AS group showed good correlation (r = 0.77; P < 0.01). In the MMD group, the ASL-CBF values (2525 ms) overestimated the PET-CBF values as the regional CBV values increased (r = 0.35; P < 0.01). When the regions of interest were divided into two subgroups according to the degree of arterial stenosis by MRA, the correlation coefficient between the ASL-CBF (2525 ms) and PET-CBF values improved (mild stenosis: r = 0.36; P = 0.06; severe stenosis: r = 0.51; P < 0.01). CONCLUSION: The accuracy of CBF measurements using ASL-MRI differed between patients with MMD and AS. The prominent increase of CBV and the degree of arterial stenosis may have affected the accuracy of ASL-CBF in patients with MMD.

Long-term prognosis of 452 moyamoya disease patients with and without revascularization under perfusion-based indications.

OBJECTIVES: To evaluate the long-term outcomes of patients treated under our perfusion-based strategy and assess whether conservative treatment without surgical treatment under our strategy is acceptable. MATERIALS AND METHODS: A total of 315 adult and 137 pediatric MMD patients (follow-up period ≥ 3 years from 2001 to 2020) were included. Follow-up events in each patient group (pediatric or adult, surgically treated or conservatively treated) were evaluated and compared to each other using a log-rank test. Risk factors for stroke and nonstroke events were also investigated using a multivariate Cox proportional hazard model. RESULTS: In adult-onset patients, the stroke event rates (person-year %) were not different between surgically treated patients and conservatively treated patients (2.00 % vs. 1.59 %, p = 0.558); however, conservative patients showed a higher stroke rate than surgically treated hemispheres (0.34 %; p = 0.025) and hemorrhagic stroke was the major type (18/26, 69.2 %). Hemorrhagic onset was associated with increased risk of stroke in adults (hazard ratio (95 % confidence interval) = 2.43 (1.10-5.36)). In pediatric-onset patients, no conservatively treated patients experienced stroke; however, nonstroke events occurred more frequently than in surgically treated hemispheres (4.86 % vs. 1.71 %, p = 0.020 for transient ischemic attack; and 7.91 % vs. 1.31 %, p < 0.001 for asymptomatic progression on magnetic resonance angiography). CONCLUSIONS: In adult patients, conservatively treated patients experienced stroke more frequently, especially hemorrhagic stroke. An additive strategy to prevent stroke in hemorrhagic-onset patients without hemodynamic disturbance seems to be needed. Pediatric patients with mild hemodynamic disturbance can be safely observed without initial surgical intervention, but close follow-up for disease progression is necessary.

Spatial coefficient of variation of arterial spin labeling MRI for detecting hemodynamic disturbances measured with 15O-gas PET in patients with moyamoya disease.

PURPOSE: The aim of this study was to investigate whether the spatial coefficient of variation of arterial spin labeling (ASL-CoV) acquired in clinical settings can be used to estimate the hemodynamic disturbances measured with 15O-gas positron emission tomography (PET), especially an increased oxygen extraction fraction (OEF), in patients with moyamoya disease. METHODS: We evaluated 68 adult patients with moyamoya disease who underwent ASL (postlabeling delay (PLD) = 1525 ms and 2525 ms) and PET. Regional values were measured using the middle cerebral artery territorial atlas divided into proximal, middle, and distal regions based on the arterial transit time, and correlations of ASL-CoV with cerebral blood flow, cerebral blood volume, mean transit time, and OEF, as well as the relationship between increased OEF and ASL-CoV, were evaluated. RESULTS: Regardless of the choice of region and PLD, ASL-CoV was significantly correlated with PET-measured parameters, including OEF (|ρ|= 0.30-0.80, P < 0.001). Regions with an increased OEF showed a significantly higher ASL-CoV than regions with a nonincreased OEF (P ≤ 0.03) regardless of the choice of region and PLD. The accuracy of identification of an increased OEF was highest when using a PLD of 1525 ms and the middle region (area under the curve = 0.750; using a cutoff value of 31.27, sensitivity = 97.4%, specificity = 41.7%, negative predictive value = 92.6%, and positive predictive value = 67.9%). CONCLUSION: ASL-CoV may help identify patients with increased OEF.

Quantitative collateral assessment evaluated by cerebral blood volume measured by CT perfusion in patients with acute ischemic stroke.

OBJECTIVES: Collateral status (CS) is considered a predictor of clinical outcome after reperfusion therapy (RT) in patients with acute ischemic stroke (AIS). We proposed a quantitative assessment of CS using cerebral blood volume (CBV) measured by computed tomography perfusion (CTP) imaging. MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board. Between February 2019 and September 2020, 60 patients with anterior circulation large-vessel occlusion who presented to our institution within 8 h after stroke onset were included. The ratio of the average CBV values in the affected middle cerebral artery (MCA) territories to the unaffected side was defined as the CBV ratio. CS was assessed by scores from previously reported qualitative scoring systems (Tan & regional leptomeningeal collateral (rLMC) scores). RESULTS: The CBV ratio was an independent factor contributing to a good functional outcome (P<0.01) and was significantly correlated with the Tan score (ρ=0.73, P<0.01) and the rLMC score (ρ=0.77, P<0.01). Among the patients with recanalization, the CBV ratio was a useful parameter that predicted both a good functional outcome (area under the receiver operating characteristic curve (AUC-ROC), 0.76; 95% CI, 0.55-0.89) and a good radiological outcome (AUC-ROC, 0.90; 95% CI, 0.72-0.97), and it was an independent predictor for good radiological outcome (OR: 4.38; 95% CI:1.29-14.82; P<0.01) in multivariate models. CONCLUSIONS: The CBV ratio is a suitable parameter for evaluating CS quantitatively for patients with AIS that can predict patient response to recanalization.

[A Case of Cerebral Tuberculoma].

Cerebral tuberculoma is a rare and serious form of tuberculosis. Despite advancements in imaging and laboratory diagnostics, it is challenging to diagnose cerebral tuberculoma due to its insidious nature and nonspecific findings. A 56-year-old woman was referred to our hospital for headaches. The patient had previously undergone treatment for pulmonary tuberculosis, which had been completely cured 2 months prior to presentation. Brain MRI revealed an enhanced mass lesion with surrounding edema in the right frontal lobe. Although a mild increase in the serum carcinoembryonic antigen(CEA)level and a moderate accumulation of FDG on FDG-PET indicated inflammatory changes or a malignant brain tumor, other imaging and laboratory findings were nonspecific. The mass lesion was indistinguishable from a brain tumor. Hence, the patient underwent surgical removal, and the pathological diagnosis was tuberculoma. In patients with a history of tuberculosis, cerebral tuberculoma should be considered in the differential diagnosis of intracranial mass lesions, even if the original lesion is completely cured. A mild increase in the serum CEA level and a moderate accumulation of FDG on FDG-PET were considered indicative of intracranial inflammation and consistent with cerebral tuberculoma.

[Clinical Findings of Thalamic and Brainstem Glioma Including Diffuse Midline Glioma, H3K27M Mutant:A Clinical Study].

BACKGROUND: Diffuse midline glioma, H3K27M mutant is a glioma located in the thalamus, brainstem, or spine with the H3K27M mutation, which is a new entity in the 2016 revised WHO classification. The treatment of thalamic glioma(TG)and brainstem glioma(BSG), which includes diffuse midline gliomas, the H3K27M mutant is challenging, and there are no standard therapeutic strategies. It is important to determine the characteristics of these brain tumors. Here, we retrospectively reviewed 31 consecutive patients with TG and BSG who were treated at our institute between January 1994 and May 2018, including methionine-positron emission tomography(MET-PET)data. RESULTS: Fourteen patients had TG, while 17 patients had BSG. Six patients were children, and 25 were adults. Nine patients with TGs and seven with BSG were enhanced by gadolinium. Twenty-seven patients were treated with radiotherapy, and 20 patients were treated with chemotherapy. All 21 tumors that underwent surgery showed wild-type IDH. The H3K27M mutation was present in four TG and two BSG. There was no statistically significant association between methionine uptake and gadolinium contrast enhancement and tumor grade. The median overall survival period(OS)of all cases was 16.9 months, whereas those of TG and BSG were 22.8 and 10.0 months, respectively. CONCLUSION: Because TG and BSG still have poor prognoses, it is necessary to elucidate the pathology of the disease and establish its standard therapy.

[A Case Report of Clivus Chordoma Presenting with Cerebrospinal Fluid Rhinorrhea].

Chordomas are uncommon tumors occurring from remnants of the notochord. They are mainly localized in the sacrococcygium, the spine and the central skull base. Here we report a rare case of clivus chordoma presenting with cerebrospinal fluid(CSF)rhinorrhea. A 41-year-old man with a 11-year history of recurrent CSF rhinorrhea was found to have a clival lesion. Bone image CT revealed lytic bone destruction at the clivus. MRI showed a cystic mass with a membrane enhanced by gadolinium protruding into the sphenoid sinus thorough the bone defect. However, there was no solid component observed. The membrane was partially resected and the CSF fistula was repaired via endoscopic endonasal approach. The pathological diagnosis was chordoma, and there has been no recurrence for three years after the surgery. It is necessary for chordoma to be considered as a differential diagnosis for cystic lesions of the clivus when the cyst membrane is enhanced by gadolinium.

[Remarkable Recovery of Chronic Symptoms in an Adult with Middle Fossa Convexity Arachnoid Cyst after Cystoventriculostomy:A Case Report].

Intracranial arachnoid cysts(ACs)are thought to develop during infancy and remain clinically asymptomatic in most cases. AC is often diagnosed incidentally during imaging studies. The prognosis for the recovery of newly developed symptoms is usually favorable. However, the prognosis following surgery for chronic symptoms is still unclear. Herein, we report the case of an adult patient with right convexity AC whose chronic symptoms improved after surgery. The patient was a 63-year-old woman who had an AC in her right temporal convexity since the age of 59, without any symptoms, which was incidentally diagnosed on MRI. At 61 years of age, she visited a hospital complaining of slight weakness in her left upper limb. No changes were found on the MRI scan, but her visual field indicated the presence of a left homonymous hemianopia, and her cognitive function had decreased slightly. Two years later, she developed modest left hemiparesis;therefore, she underwent cystoventriculostomy to improve the symptoms of hemiparesis. After the surgery, the left hemiparesis recovered fully, and a remarkable improvement was noted in the left homonymous hemianopia and the degenerated cognitive functions. There are no clear guidelines regarding the surgical indications for AC in adults. Many reports suggest that new symptoms related to AC can be improved with surgery. However, amelioration of chronic symptoms has rarely been reported. The present case indicates that it is possible to improve the chronic symptoms of AC in adults with surgical procedures.

[Cerebellar Glioblastoma with Intrathecal Dissemination:A Report of Four Cases].

Primary cerebellar glioblastoma is a rare disease that accounts for 0.4-3.4% of glioblastoma multiforme(GBM)cases. The clinicopathological characteristics and prognosis of primary cerebellar GBM are not well understood due to its rarity and the lack of an established treatment strategy. To elucidate the prognostic factors and dissemination pattern, we retrospectively assessed four cases of cerebellar GBM that we treated between 2003 and 2013. All cases involved men, and the age range was 53 to 76 years(median 69.5 years);each patient underwent surgical removal and received adjuvant chemotherapy or radiotherapy. Every cerebellar GBM patient developed intrathecal dissemination at every stage of cerebellar GBM. Two patients had spinal metastases with tumor recurrence, and no patient had brain stem invasion. IDH1 mutation and MGMT expression were both negative in three cases. The median overall survival of cerebellar GBM patients was 13.8 years, and the median progression-free survival was 5.5 years, which is similar to that reported in previous reports-and similar in terms of results-for supratentorial GBM treated at the same time at our institution. In conclusion, the prognosis of cerebellar GBM appears to be similar to that of supratentorial GBM;however, the pattern of tumor progression, such as intrathecal dissemination, is different. Craniospinal irradiation on cerebellar GBM should be carefully considered with frequent follow-up by whole spine survey using MRI.

Unraveling Specific Brain Microstructural Damage in Moyamoya Disease Using Diffusion Magnetic Resonance Imaging and Positron Emission Tomography.

BACKGROUND AND PURPOSE: Chronic ischemia may induce brain microstructural damage and lead to neurocognitive dysfunction in patients with Moyamoya disease (MMD). We applied neurite orientation dispersion and density imaging (NODDI) and 15O-gas positron emission tomography (PET) to elucidate the specific ischemic brain microstructural damage of MMD in the cortex and the white matter. MATERIALS AND METHODS: Thirty-one patients (16-63years old, 9 males) and 20 age- and sex-matched normal controls were enrolled in this study. NODDI evaluates quantitative parameters reflecting neurite and axonal density, network complexity and the interstitial fluid in all participants. Of 31 patients, 12 newly diagnosed patients were evaluated with PET, also. We evaluated correlations between the microstructural parameters of NODDI and the hemodynamic and metabolic parameters of PET, the relationship between NODDI and clinical severity of each hemisphere (Normal, Asymtpomatic, Symptomatic, and Infarcted) as well as neurocognitive performance. RESULTS: All NODDI parameters significantly correlated with PET parameters (absolute r = 0.46-0.83, P ≤ .048) and clinical severity (P < .001), suggesting that neurite and axonal density and network complexity decreased, and the interstitial fluid increased, as the ischemic burden became severe. NODDI parameters reflecting neurite and axonal density and network complexity significantly correlated with neurocognitive profiles (r = 0.36-0.64, P ≤ .048), but the interstitial fluid component did not. CONCLUSIONS: Chronic ischemia in patients with MMD may induce decreased neurite and axonal density, simplified network complexity, and may lead to neurocognitive dysfunction. The increased interstitial fluid accompanying hemodynamic impairment may not be identical to the decreased neurite density and might be driven by another mechanism.

[Effectiveness of Color-Coded Doppler Ultrasonography for Detecting the Trajectory in the Surgical Management of Distal ACA Aneurysms].

Distal anterior cerebral artery(DACA)aneurysms are relatively rare. The detection of the surgical trajectory of DACA aneurysmal clipping is difficult because DACA aneurysms are located at various sites in the ACA. The purpose of this study was to evaluate the effectiveness of intraoperative use of color Doppler ultrasonography for the surgery of DACA aneurysms. DACA aneurysms of ten patients(three men, seven women;64.5 years old on median)were examined using intraoperative color Doppler imaging(CDI), which was performed before microscopic procedures, to detect the location of the aneurysms. Among them, six patients had ruptured aneurysms with diameters ranging from 2.5 to 10.8mm, and four of them had intracerebral hematomas. All the aneurysms and surrounding arteries were clearly detected using CDI. Moreover, in larger aneurysms, blood flow dynamics inside the aneurysm were also observed using CDI. As a result, we concluded that the intraoperative use of color Doppler ultrasonography was effective of detecting the trajectory for the DACA aneurysms without causing any damage to the brain by redundant dissections.

Microstructural Damage in Normal-Appearing Brain Parenchyma and Neurocognitive Dysfunction in Adult Moyamoya Disease.

Background and Purpose -Microstructural damage in the brain induced by chronic ischemia is suggested to play a pivotal role in the neurocognitive dysfunction of adults with Moyamoya disease (MMD). We investigated specific changes in the brain microstructure and their correlations with neurocognitive dysfunction in patients with MMD using a multishell diffusion magnetic resonance imaging technique called neurite orientation dispersion and density imaging. Methods- We evaluated 26 patients with MMD (16-63 years old, 20 females) and 20 age- and sex-matched normal volunteers using neurite orientation dispersion and density imaging and neuropsychological batteries. Neurite orientation dispersion and density imaging calculates 2 parameters: the intracellular volume fraction (Vic), which reflects the axon density in the white matter and dendrite density in the cortex, and the orientation dispersion index (OD), which reflects the network complexity. The microstructural damage and its correlation with neurocognitive performance were evaluated by performing a whole-brain analysis using SPM12 and correlation analysis with regional values. Results- Patients with MMD had significantly lower Vic in the white matter and a lower OD mainly in the cortex than those of the controls ( P<0.001, family-wise error corrected). Of all neuropsychological scores, Processing Speed Index (PS) exhibited the strongest correlation with Vic in the white matter ( P<0.001, family-wise error corrected). The Vic and OD values for regions with group differences, including both temporoparietal and frontal areas, correlated with neurocognitive performance (absolute r=0.37-0.64; P<0.01). Conclusions- Chronic ischemia in MMD may decrease the axon density in the white matter and dendrite density in the cortex (Vic) and simplify network complexity (OD), leading to neurocognitive dysfunction. Processing Speed Index may be the most sensitive index used to evaluate the ischemic burden, and the posterior part of the brain may play an important role in neurocognitive function. Clinical Trial Registration- URL: http://www.umin.ac.jp/ctr/ . Unique identifier: UMIN000023082.

Unique Angiographic Appearances of Moyamoya Disease Detected with 3-Dimensional Rotational Digital Subtraction Angiography Imaging Showing the Hemodynamic Status.

BACKGROUND: The aim of this study was to identify the unique morphological arterial features in patients with moyamoya disease on 3-dimensional rotational digital subtraction angiography. MATERIALS AND METHODS: One hundred seven hemispheres of 58 consecutive patients with moyamoya disease that were analyzed with fused 3-dimensional images of internal carotid angiograms and vertebral angiograms that were marked with different colors were reviewed. Angiographic findings in the posterior watershed area were classified, and the utility of the classification was analyzed by comparing it with clinical presentations and quantitative hemodynamic parameters obtained with positron emission tomography. RESULTS: Two unique angiographic appearances were identified. A vacant vessel appearance (no arterial inflow despite absence of cortical infarction) was observed mostly in transient ischemic attack hemispheres. In hemispheres with a vacant vessel appearance, cerebral blood flow was decreased, cerebral blood volume was increased, and mean transit time was prolonged significantly (P = .00017, P = .0061, and P = .00026, respectively). A cocktail vessel appearance (mixture of carotid and vertebral arterial flow) was most commonly observed in asymptomatic cases, as well as in ischemic hemispheres. Cerebral blood volume increased and mean transit time was prolonged significantly (P = .036 and P = .014, respectively) in hemispheres with a cocktail vessel appearance. The trend of progression in hemodynamic severity in the order of normal appearance, cocktail vessel appearance, and vacant vessel appearance in the watershed area was statistically significant. CONCLUSION: Fused 3-dimensional digital subtraction angiography demonstrated unique angiographic features in the watershed area, and this represented the degree of cerebral hemodynamic impairment in moyamoya disease.

[A Rare Case of Radiation-Induced Meningioma that Occurred Only 3 Years and 6 Months after Radiation Therapy for Oligodendroglioma].

We describe an adult case of radiation-induced meningioma(RIM)that was identified within a short interval from the initial treatment for brain tumor. A 45-year-old woman, who had tumor resection followed by radiation therapy for right frontal oligodendroglioma, showed a small enhanced lesion on the right frontal region 3 years and 6 months after the initial radiation therapy. The pathological diagnosis was meningioma(World Health Organization(WHO)grade I)and the Ki-67 labeling index was 3.2%. Most RIMs occur after a long period of time(18.7-24.0 years on average)following radiation therapy. Several studies have suggested that the period before the occurrence of RIM is correlated with both the age of a patient and the radiation dose at the time of radiation therapy. A patient that receives a higher dose of radiation at a younger age has a higher risk of RIM occurrence. In this case, the patient was middle aged;however, she was exposed to a high dose of radiation(54 Gy). High-dose radiation might induce the early onset of RIM. Recently, treatments for glioma have been developed, thus resulting in an increased long-term survival rate among patients. Physicians must pay attention not only to the recurrence of gliomas but also to the occurrence of RIMs.

Correlation between Clinical Presentations and Hemodynamic Parameters Measured by Dynamic Susceptibility Contrast Magnetic Resonance Imaging in Adult Patients with Moyamoya Disease.

BACKGROUND: The examination of cerebral hemodynamics is indispensable for the clinical management of patients with moyamoya disease (MMD). In this study, we examined the correlation between clinical presentations and hemodynamic parameters measured by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) in adult patients with MMD. METHODS: One hundred fifty-seven hemispheres in 122 adult patients with MMD were examined by DSC-MRI to measure the regional relative cerebral blood volume (CBV) and relative mean transit time (MTT). The patients were divided into 4 groups based on their clinical presentations: a nonsymptomatic (NS), hemorrhagic (H), infarction (I), and transient ischemic attack (T) group. The regional CBV and MTT values were compared among the 4 groups. RESULTS: The relative value of CBV was significantly higher in groups T and I than in the NS group (P < .01). The CBV of group H was higher than that of the NS group only in the frontal lobe cortex. There were no significant statistical differences among the 3 symptomatic groups. Prolongation of the MTT in comparison with the cerebellum (MTT delay) was significantly higher in groups T and I than in the NS group in all regions of the cerebral cortex (P < .05). The MTT delay was significantly lower in group H than in group T in the frontal lobe and the Rolandic area (P < .05). CONCLUSIONS: Hemodynamic factors measured by DSC-MRI reflected the variable clinical presentations of patients with MMD. DSC-MRI is a useful modality for evaluating the clinical conditions of individual adult patients with MMD.