Directional Regulation of Extrasellar Extension by Sellar Dura Integrity and Intrasphenoidal Septation In Pituitary Adenomas.

OBJECTIVE: Pituitary macroadenomas extend into the extrasellar space, such as the sphenoid sinus, cavernous sinuses, and suprasellar region. However, factors that regulate the direction of their extensions into the surrounding anatomical structures remain unknown. METHODS: This retrospective study included 162 patients who were treated for pituitary adenomas that had maximum diameters greater than 20 mm. According to the direction of adenoma extension, patients were divided into 4 groups: group A, inferior into the sphenoid sinus; group B, lateral into the cavernous sinus; group C, suprasellar region with enlarged sella turcica; and group D, supraellar region without enlarged sella turcica. Several anatomical structures surrounding the sella turcica were evaluated statistically, and multivariate logistic regression analysis was performed if the structures met the determining factors of adenomas extensions. RESULTS: The maximum diameter of adenomas was significantly larger in groups A and D. The maximum diameter of the diaphragmatic foramen was largest in group C (19.3 mm) and was significantly narrower in groups B (12.7 mm) and D (12.5 mm). Intrasphenoid septation, attached on the midline of the sella turcica, was observed most frequently in group D (78.6%) and was not detectable in group A (0%). Extension into the cavernous sinus, classified as dural discontinuity, was highly prevalent in group B (80.0%) and was uncommon in group C (12.3%). Erosion of the posterior clinoid process was most apparent in group B (92.0%). CONCLUSIONS: The integrity of the sella dura and the intrasphenoid septation can regulate adenoma extension by encouraging their growth towards paths of least resistance.

Delayed Occurrence of Diabetes Insipidus After Transsphenoidal Surgery with Radiologic Evaluation of the Pituitary Stalk on Magnetic Resonance Imaging.

BACKGROUND: Diabetes insipidus (DI) is a major complication of transsphenoidal surgery (TSS). DI usually occurs within a couple of days after TSS. Delayed occurrence of postoperative DI is rarely observed and its developing mechanisms remain unknown. METHODS: Six patients were identified as having postoperative delayed DI, which was defined as DI that first occurred 2 or more weeks after TSS. They consisted of 1 male and 5 females, and their mean age was 38.3 years (range, 10-76 years). Five patients were histologically diagnosed with Rathke cleft cyst (RCC), and one had RCC coexisting with prolactin-secreting adenoma. Sequential T1-weighted magnetic resonance imaging was evaluated for hyperintensity (HI) in the pituitary stalk and the posterior lobe, indicating the location of antidiuretic hormone. RESULTS: No patients had any DI before TSS. Delayed DI occurred 2 weeks to 3 months after TSS and persisted for 2 weeks to 5 months. T1-weighted magnetic resonance imaging showed that the HI in the posterior lobe became faint but did not disappear after DI occurrence, and their intensities increased with recovery from DI. In contrast, the HI in the pituitary stalk was found faintly preoperatively and turned clear postoperatively and decreased with recovery from DI. The morphologic patterns were dependent on DI duration. CONCLUSIONS: In the delayed occurrence of DI, it was suggested that preoperative antidiuretic hormone transport was mildly congested yet not completely blocked when DI manifested postoperatively. Gradual spreading of inflammation to the infundibulum after RCC removal was considered as 1 possible mechanism of this delayed DI development.

Contribution of sellar dura integrity to symptom manifestation in pituitary adenomas with intratumoral hemorrhage.

PURPOSE: Although hemorrhage within pituitary adenomas frequently exacerbates the symptoms, there are many grades of severity. Moreover, the contributing factors for symptom severity are still controversial. METHODS: This retrospective study included 82 patients who underwent transsphenoidal surgery for pituitary adenomas with intratumoral hemorrhage. The grades of preoperative symptoms were classified into group A, asymptomatic or minor symptoms; group B, moderate symptoms sufficient for complain; and group C, severe symptoms disturbing daily life. RESULTS: The hemorrhage volume within an adenoma was significantly higher in group C (92.6%) than in groups A (48.6%) and B (58.7%). Both headache and diplopia were dominant in group C, occurring in 72.2% and 27.8% of the patients, respectively. In group C, there was no significant difference in frequency between adenoma extensions into the sphenoid sinus (0%) and involvement of the cavernous sinus of Knosp grade 4 (0%), and extensions into the suprasellar region were not common (38.9%). The most distinctive feature was that "no extrasellar extension" was found only in group C (41.2%), and "multidirectional extension" was not detected in this group (0%). Multiple regression analysis revealed that the most powerful determining factors were the high frequencies of intratumoral hemorrhage and lack of extrasellar and multidirectional extensions. CONCLUSION: Rapid volume expansion of a hematoma and lack of extension or unidirectional extension might lead to significant compression of the sellar and surrounding structures. Of note, the integrity of the sellar dura might contribute to the acute onset of symptom manifestations caused by hemorrhage in pituitary adenomas.

Preoperative Evaluation of the Interface Between Tuberculum Sellae Meningioma and the Optic Nerves on Fast Imaging with Steady-State Acquisition for Extended Endoscopic Endonasal Transsphenoidal Surgery.

INTRODUCTION: Endoscopic endonasal transsphenoidal surgery (EETS) is increasingly applied to treat tuberculum sellae meningiomas. However, if the tumor adheres firmly to the optic nerve, dissection of the interface between both structures should be prudent to preserve visual function. The purpose of this study was to investigate whether tumor adhesion to the optic nerve can be predicted preoperatively by fast imaging with steady-state acquisition (FIESTA). METHODS: Twenty-two patients with tuberculum sellae meningioma treated with EETS were retrospectively identified. Clinical characteristics, radiologic studies, intraoperative findings, and outcomes were reviewed from their clinical charts. RESULTS: Patients' symptoms included visual function impairment in 18 patients and headaches in 4 patients. Symptoms were resolved in 19 patients after operation. Preoperative radiologic evaluation was performed in 44 sides (22 patients) of the interface between tumors and the optic nerves and showed absence of peritumoral hyperintensity on FIESTA in 7 sides in 7 patients. In 5 of the 7 sides, tumor dissection was complicated by firm adhesion to the optic nerves. Among these cases, visual functions were unchanged in 1 patient after complete removal of the adhesion but substantially improved in 3 patients after partial resection. In the remaining 37 sides with preoperative peritumoral hyperintensity, no adhesion was found between both structures intraoperatively. CONCLUSIONS: Absence of peritumoral hyperintensity between tuberculum sellae meningioma and the optic nerve on FIESTA may indicate firm adhesion at the interface, severely complicating complete removal. Preoperative recognition of this adhesion is important for safe tumor removal and preservation of visual functions.

Long-term predictive factors of the morphology based outcome in bare platinum coiled intracranial aneurysms: Evaluation by pre- and post-contrast 3D time-of-flight MR angiography.

PURPOSE: Our aim was to identify long-term predictive factors of the morphology-based outcome (MBO) of bare platinum coiled intracranial aneurysms. MATERIALS AND METHODS: A retrospective analysis of 96 bare platinum coiled intracranial aneurysms followed up from 1997 to 2016 using pre- and post-contrast 3D time-of-flight MR angiography (MRA) was performed. Logistic regression analysis was used to identify factors associated with a positive history of surrounding coil mass enhancement (SCME) and poor MBO. Spearman's rank correlation test was used to analyze the relationship between the initial angiographic result (IAR) class, sequential change of the SCME category, and MBO grade. RESULTS: Factors independently associated with poor MBO were incomplete IAR (OR=14.94, 95%CI: 2.46, 289.21, P=0.002) and a history of SCME (OR=4.13, 95% CI: 1.05, 18.65, P=0.043). The MBO grade strongly correlated with the IAR class (correlation coefficient [r]=0.84, P<0.0001). MBO grade correlated with sequential change of the SCME category (r=0.56, P<0.0001). The sequential change of the SCME category correlated with IAR class (r=0.53, P<0.0001). CONCLUSION: Although IAR and its class were strong long-term predictive factors of MBO, a history of SCME and upgrading of sequential change of SCME category were also long-term predictive factors of the MBO of bare platinum coiled intracranial aneurysms.

MR Spectroscopy to Distinguish between Supratentorial Intraventricular Subependymoma and Central Neurocytoma.

PURPOSE: The purpose of this study was to discriminate supratentorial intraventricular subependymoma (SIS) from central neurocytoma (CNC) using magnetic resonance spectroscopy (MRS). METHODS: Single-voxel proton MRS using a 1.5T or 3T MR scanner from five SISs, five CNCs, and normal controls were evaluated. They were examined using a point-resolved spectroscopy. Automatically calculated ratios comparing choline (Cho), N-acetylaspartate (NAA), myoinositol (MI), and/or glycine (Gly) to creatine (Cr) were determined. Evaluation of Cr to unsuppressed water (USW) was also performed. Mann-Whitney U test was carried out to test the significance of differences in the metabolite ratios. Detectability of lactate (Lac) and alanine (Ala) was evaluated. RESULTS: Although a statistically significant difference (P < 0.0001) was observed in Cho/Cr among SIS, control spectra, and CNC, no statistical difference was noted between SIS and control spectra (P = 0.11). Statistically significant differences were observed in NAA/Cr between SIS and CNC (P = 0.04) or control spectra (P < 0.0001). A statistically significant difference was observed in MI and/or Gly to Cr between SIS and control spectra (P = 0.03), and CNC and control spectra (P < 0.0006). There were no statistical differences between SIS and CNC for MI and/or Gly to Cr (P = 0.32). Significant statistical differences were found between SIS and control spectra (P < 0.0053), control spectra and CNC (P < 0.0016), and SIS and CNC (P < 0.0083) for Cr to USW. Lac inverted doublets were confirmed in two SISs. Triplets of Lac and Ala were detected in four spectra of CNC. CONCLUSION: The present study showed that MRS can be useful in discriminating SIS from CNC.

Cranial Pachymeningeal Involvement in POEMS Syndrome: Evaluation by Pre- and Post-contrast FLAIR and T1-weighted Imaging.

PURPOSE: To evaluate the cranial pachymeningeal involvement of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) syndrome using pre- and post-contrast fluid-attenuated inversion recovery (FLAIR) and T1-weighted imaging (T1WI). METHODS: The appearance of pachymeningeal involvement in nine cases of POEMS syndrome was evaluated using pre- and post-contrast FLAIR and T1WI. The degree of pachymeningeal thickening was graded as normal or abnormal using pre-contrast FLAIR. The degrees of contrast enhancement effect were evaluated based on pre- and post-contrast images, and recorded in each of three separate anatomical areas, i.e., the falx cerebri, cerebral convexity, and tentorium cerebelli. The degrees of contrast enhancement of pachymeninges were graded as not detected (ND), positive, or prominent on post-contrast FLAIR, and normal range (NR), positive, and prominent on post-contrast T1WI. RESULTS: Pre-contrast FLAIR demonstrated 41% of pachymeningeal anatomical regions as areas of thickening. Post-contrast FLAIR did not detect any contrast enhancement on 26% of the regions but showed positive enhancement on 30% and prominent enhancement on 44%. Post-contrast T1WI showed normal range enhancement on 48%, positive enhancement on 11%, and prominent enhancement on 41% of the regions. Post-contrast FLAIR showed the highest percentage for detection of pachymeningeal abnormalities (74%). CONCLUSION: Post-contrast FLAIR may contribute to objective judgment in the evaluation of pachymeningeal involvement in POEMS syndrome.

Prediction of postoperative diabetes insipidus using morphological hyperintensity patterns in the pituitary stalk on magnetic resonance imaging after transsphenoidal surgery for sellar tumors.

PURPOSE: Diabetes insipidus (DI) remains a complication of transsphenoidal surgery (TSS) for sellar and parasellar tumors. Antidiuretic hormone (ADH) appears as hyper intensity (HI) in the pituitary stalk and the posterior lobe of the pituitary gland on T1-weighted magnetic resonance (MR) imaging. Its disappearance from the posterior lobe occurs with DI, indicating a lack of ADH. The appearance of HI in the pituitary stalk indicates disturbances in ADH transport. METHODS: This retrospective study included 172 patients undergoing TSS for sellar tumors at our institute from 2006 to 2014. Sequential T1-weighted MR images without enhancement were evaluated for HI in the pituitary stalk and the posterior lobe to assess the localization of ADH before and at intervals after TSS. DI was assessed pre- and postoperatively. HI in the pituitary stalk showed the following morphology: (1) ovoid in the distal end of the pituitary stalk (group A), (2) linear in the distal part of the pituitary stalk (group B), (3) linear in the whole pituitary stalk (group C). RESULTS: Preoperative DI occurred in 6 patients (3.5 %) with no HI observed in the posterior lobe. Postoperative DI was transient in 82 patients (47.7 %), and permanent in 11 (6.4 %). One week after surgery, HI was absent in the posterior lobe in 74 patients (43.0 %), and present in the pituitary stalk in 99 patients (57.6 %); both were significantly correlated with postoperative DI (p < 0.001). The absence of HI in the posterior lobe (A, 48.9 %; B, 68.3 %; C, 92.3 %), persistence of DI (A, 3.7 days; B, 45.9 days; C, 20.5 months), and duration until HI recovery in the posterior lobe (A, 3.6 months; B, 6.8 months; C, 22.9 months) were greatest in group C, followed by group B, and then group A. Fourteen group A patients did not have postoperative DI despite having HI in the pituitary stalk and the posterior lobe. Four group C patients developed permanent DI with persistence HI in the pituitary stalk. CONCLUSION: HI in the pituitary stalk and its absence in the posterior lobe indicated postoperative DI, which was transient if HI was detected in the pituitary stalk. DI duration could be predicted by the length of HI in the pituitary stalk, which corresponded to the degree of ADH transport obstruction.

Optimizing the Volume of the Initial Framing Coil to Facilitate Tight Packing of Intracranial Aneurysms.

BACKGROUND: During endovascular treatment of an aneurysm, the importance of the initial coil volume for facilitating tight packing is unclear. We retrospectively studied the relationships between initial packing density (PD; initial coil volume divided by aneurysm volume), final PD (volume of all coils divided by aneurysm volume). METHODS: We reviewed 105 aneurysms in 98 patients who underwent endovascular coiling between April 2011 and March 2014. The initial coil was defined as the first coil in the single-catheter method and the first 2 coils in the double-catheter method. The patient data were divided into groups with or without a final PD ≥20%, and the significant predictors of a final PD ≥20% were determined using multivariable logistic regression. The optimal cutoff value for the initial PD was determined using a receiver operating characteristic curve. RESULTS: Of 105 aneurysms, 56 and 49 were treated with single- and double-catheter methods, respectively. Statistically significant differences in rupture status, neck size, dome/neck ratio, and initial PD were observed between aneurysms with and without a final PD ≥20% (all P < 0.05). Multivariate analysis showed that initial PD (P = 0.025; odds ratio, 1.22) and rupture status (P = 0.002; odds ratio, 0.19) were significantly associated with a final PD ≥20%. Using receiver operating characteristic curve analysis, the cutoff points of initial PD to achieve a final PD ≥20% were 8.0% and 10.0% in single- and double-catheter groups, respectively. CONCLUSIONS: Initial PD appears to be a critical factor for achieving tight packing.

Prediction of carotid artery in-stent restenosis by quantitative assessment of vulnerable plaque using computed tomography.

BACKGROUND AND PURPOSE: To assess the relationship between plaque volume evaluated by multidetector computed tomographic angiography (MDCT) and in-stent restenosis (ISR) after carotid artery stenting (CAS). MATERIALS AND METHODS: From a retrospectively maintained database, data were collected for 52patients with carotid artery stenosis treated with CAS between 2007 and 2012. We defined ISR of≥50% as a peak systolic velocity≥200cm/s on echo-duplex scan. Carotid plaques were subdivided into four components according to radiodensity in Hounsfield units (HU) as follows: <0, 0-60, 60-130, and>600HU. Risk factors that influenced ISR were compared using univariate and multivariate Cox regression analyses. RESULTS: During a median follow-up period of 36months, ISR of≥50% was detected in five patients (9.6%). In the univariate Cox proportional hazard regression analysis, renal insufficiency, coronary artery disease, total plaque volume, and plaque volumes with radiodensities<0 and≥600HU increased the risk for ISR (P<0.10). When the significant risk factors determined from the univariate analysis were subjected to a multivariate analysis, only the volumes of the plaque components with radiodensities<0 HU independently predicted the development of ISR (hazard ratio: 1.041; 95% confidence interval: 1.006-1.078; P=0.021). CONCLUSION: Our data suggest that the high volume of the plaque components with radiodensities<0HU was independently associated with the increased risk of ISR after CAS. Quantitative and qualitative tissue characterizations of carotid plaques using MDCT might be a useful predictive tool of the development of ISR.

Malignant transformation of diffuse infiltrating glial neoplasm after prolonged stable period initially discovered with hypothalamic hamartoma.

We present a case of malignant transformation of diffuse infiltrating glial neoplasm after a prolonged stable period on magnetic resonance imaging (MRI) and spectroscopy (MRS) initially discovered with a hypothalamic hamartoma. Although MRI and MRS suggest the possibility of malignant transformation in future, they cannot precisely predict the timing of rapid growth.

Differences between glioblastomas and primary central nervous system lymphomas in 1H-magnetic resonance spectroscopy.

PURPOSE: The present study aimed to distinguish between glioblastomas and primary central nervous system lymphomas (PCNSLs) using (1)H-magnetic resonance spectroscopy (MRS), especially glutamate (Glu)/creatine (Cr) and Glu/Glu+glutamine (Gln) ratios. MATERIALS AND METHODS: A total of 46 patients (31 cases diagnosed with glioblastoma, 15 with PCNSL) were examined by in vivo single-voxel proton (1)H-MRS with a 3-T MR imaging system. Differences in absolute concentration of Cr, choline/Cr, lipid (1.3 ppm)/Cr, Glu+Gln/Cr, Glu/Cr, and Glu/Glu+Gln ratios among groups were evaluated with Mann-Whitney U tests. RESULTS: PCNSLs [3.408 ± 1.194 (standard deviation)] showed significantly higher Glu/Cr ratios as compared to glioblastomas (2.220 ± 0.942; P = 0.003) [Glu/Cr cutoff ratio of 2.509 showed a sensitivity of 88 % (7/8) and a specificity of 92 % (22/24)], while glioblastomas (0.539 ± 0.098) showed significantly lower Glu/Glu+Gln ratios as compared to PCNSLs (0.728 ± 0.147; P < 0.001) [Glu/Glu+Gln cutoff ratio of 0.558 showed a sensitivity of 69 % (18/26) and a specificity of 100 % (13/13)]. And PCNSLs (1.101 ± 0.387) showed significantly higher Cho/Cr ratios as compared to glioblastomas (0.850 ± 0.465; P = 0.026). CONCLUSION: Glu/Cr, Glu/Glu+Gln, and Cho/Cr ratios may be useful in distinguishing between glioblastomas and PCNSLs.

Striatal hemihypoplasia: an early embryonic variant of cerebral hemiatrophy.

We present a case of hemihypoplasia of the striatum with ipsilateral cerebral hemispheric atrophy. The head of the caudate nucleus and putamen were hypoplastic, and gray matter cell bridges between them located in the anterior limb of the internal capsule were sparse. Cerebral atrophy was accompanied by ipsilateral mesial temporal sclerosis without thalamic atrophy. The anterior limb of the internal capsule showed no signal abnormalities or volume loss. These imaging findings and the hyperintensity at the fundus striati suggest an early embryonic insult of lateral striatal elevation.

Splenial and white matter lesions showing transiently-reduced diffusion in mild encephalopathy monitored with MR spectroscopy and imaging.

We report the time course of magnetic resonance imaging and spectroscopy of a case with lesions of the splenium and white matter with transiently reduced diffusion in clinically reversible encephalopathy. Initially normal spectroscopy showed slightly elevated choline. Signal abnormality in T2-weighted and fluid-attenuated inversion recovery images persisted for 90 days. Lesions of the splenium and white matter with transiently reduced diffusion in clinically reversible encephalopathy are not always reversible and may reflect heightened glial cell-membrane turnover without neuronal damage.

Prognostic paradox: brain damage around the glioblastoma resection cavity.

Hyperintense lesions around the resection cavity on magnetic resonance diffusion-weighted imaging (MR-DWI) frequently appear after brain tumor surgery due to the damage of surrounding brain. The putative connection between the lesion and the prognosis for patients with glioblastoma (GBM) was explored. This retrospective study reviewed consecutive sixty-one patients with newly diagnosed GBM. Postoperative MRI was performed within 2 weeks after the initial surgery. We classified the cases into two groups depending on whether DWI hyperintense lesions were observed or not [DWI(+) group and DWI(-) group]. Progression-free survival (PFS) and overall survival (OS) were compared between the two groups. Forty-two patients were identified. The various extents of hyperintense lesions around the resection cavity were observed in 28/42 (66.7%) cases. In the DWI(+) and DWI(-) groups, median PFS was 10.0 [95% confidence interval (CI) 8.4-11.5] and 6.7 (95% CI 4.9-8.5) months, respectively (p = 0.042), and median OS was 18.0 (95% CI 12.2-23.8) and 17.0 (95% CI 15.7-18.3) months, respectively (p = 0.254). On multivariate analysis, the presence of DWI hyperintense lesion was more likely to be an independent predictor for 6-month PFS (p = 0.019; HR, 0.038; 95% CI 0.002-0.582). Tumor recurrence appeared outside the former DWI hyperintense lesion. Hyperintense lesions surrounding the resected GBM on MR-DWI might be a favorable prognostic factor in patients with GBM.

Association between carotid plaque composition assessed by multidetector computed tomography and cerebral embolism after carotid stenting.

INTRODUCTION: We aimed to assess the relationship between atherosclerotic carotid plaque composition analyzed using multidetector computed tomography (MDCT) and the appearance of new ischemic lesions detected by diffusion-weighted images (DWI) after carotid artery stenting (CAS). METHODS: We quantitatively and qualitatively analyzed plaque characteristics in carotid arteries using MDCT before CAS in 19 patients. Carotid plaques were expediently subdivided into four components with Hounsfield unit (HU) values of <0, 0-60, 60-130, and >600. The incidence of distal embolism was evaluated with DWI. Pearson's correlation analyses were used to assess the association between plaque composition and the incidence of cerebral embolization. RESULTS: Fifteen patients (79%) demonstrated new DWI lesions after CAS. High-signal DWIs were noted as follows: one in six patients, 2 ~ 5 in five patients, 6 ~ 10 in two patients, and >10 in two patients. The mean volumes of the plaque components for HU < 0, 0-60, 60-130, and >600 were 5.4, 200, 260, and 59 mm(3), respectively. There was a strong correlation between the number of high-signal DWI lesions in the ipsilateral side and the plaque volume of HU < 0 (r = 0.927; P < 0.0001). There was a moderate correlation between the number of high-signal DWI lesions and the plaque volume of HU 0-60 (r = 0.568; P = 0.0099) and the sum total of HU < 0 and HU 0-60 (r = 0.609; P = 0.0047). CONCLUSIONS: Quantitative and qualitative tissue characterization of carotid plaques using MDCT might be a useful predictor for silent ischemic lesions after CAS.

Association fibers connecting the Broca center and the lateral superior frontal gyrus: a microsurgical and tractographic anatomy.

OBJECT: Recently, intraoperative mapping has disclosed that, in addition to the classic language centers (that is, the Broca and Wernicke centers), other cortical regions may also play an important role in language organization. In the prefrontal cortex, although the lateral superior frontal gyrus (LSFG) could have language-related functions, there are no detailed reports that demonstrate the anatomical connection between the LSFG and other well-known language cortices, such as the Broca center. To show the existence of the structural connection, white matter association fibers between the inferior frontal gyrus (IFG) and the LSFG were examined using fiber dissection (FD) and diffusion tensor (DT) imaging-based tractography. METHODS: Eight cadaveric cerebral hemispheres were dissected to reveal the association fibers between the IFG and LSFG. The DT imaging-based tractography studies targeting the prefrontal cortex were obtained in 53 right-handed patients who had no organic cerebral lesions. RESULTS: The association fiber tract between Brodmann area 44/45 (the Broca center in the dominant hemisphere) and LSFG were detected in all specimens by FD. In the DT imaging-based tractography studies, the tract was identified in all patients bilaterally, except for the 4 in whom the tract was detected only in the left hemisphere. This tract was spread significantly wider in the left than in the right hemisphere, and left lateralization was evident in male patients. CONCLUSIONS: Based on its character, this tract was named the Broca-LSFG pathway. These findings suggest a close relationship between this pathway and language organization. The structural anatomy of the Broca-LSFG pathway may explain speech disturbances induced by LSFG stimulation that are sometimes observed during intraoperative language mapping.

Automated MR spectroscopy of intra- and extraventricular neurocytomas.

PURPOSE: We evaluated the automated magnetic resonance spectroscopic (MRS) characteristics of intra- and extraventricular neurocytomas. MATERIALS AND METHODS: One extra- and 4 intraventricular neurocytomas were studied. Automated single-voxel proton MRS was performed with a 1.5 T MR scanner. The results of 6 total automated MR spectra were analyzed for each tumor. RESULTS: Lactate resonance was detected as a doublet in 3 MR spectra of 2 intraventricular neurocytomas. A peak corresponding to N-acetylaspartate (NAA) was small in 5 MR spectra of 4 intraventricular neurocytomas. Creatine (Cr) resonance was detected in all 6 MR spectra. Prominent choline (Cho) resonance was found in all 6 MR spectra. The myoinositol (MI) and/or glycine (Gly) peaks were large in 3 MR spectra of 2 intraventricular neurocytomas. CONCLUSION: The presence of the NAA signal and high MI and/or Gly signals may be characteristic features of intraventricular neurocytomas. A combination of prominent Cho resonance and detectable Cr resonance is a common feature of both intra- and extraventricular neurocytomas.

Anatomical study of the occipital sinus using contrast-enhanced magnetic resonance venography.

The frequency and anatomical features of the occipital sinus (OS) were analyzed in this study by contrast-enhanced magnetic resonance venography (MRV) with enhanced fast gradient echo three-dimensional (EFGRE3D) and we discuss the clinical usefulness of this method. The study included 555 patients who underwent contrast-enhanced MRV with EFGRE3D, and maximum intensity projection (MIP), multiplanar reformation (MPR) and multiprojection volume reconstruction (MPVR) images were obtained for the regions of interest. The frequency, size and communication of the OS with other vessels were assessed. The OS was identified in 209 of the 555 patients (37.7%). There were no statistically significant sex-related differences. The OS was observed less frequently in subjects younger than 50 years. Cranially and/or caudally, some OS were separated and communicated with multiple vessels. In five patients, the straight sinus (StS) communicated directly with the OS and not with the other sinuses; in two patients, the StS communicated with veins other than the OS only via small anastomotic veins. Many morphological differences in the OS can be seen. In addition, some OS function as the main drainage route of the intracranial veins instead of the transverse sinus or sigmoid sinus. In addition to MIP, detailed examination by MPR and MPVR is required for the preoperative evaluation of posterior cranial fossa lesions.

Anatomical study of the confluence of the sinuses with contrast-enhanced magnetic resonance venography.

INTRODUCTION: It is important that each dural sinus can be recognized during brain surgery and that the venous route can be used for interventional procedures. In this study, the anatomical features and patterns of the confluence of the sinuses were analyzed. METHODS: The technique of contrast-enhanced three-dimensional magnetic resonance venography was used in 549 patients. RESULTS: There were many anatomical variations in the confluence of the sinuses. Most cases had wide communication between the right and left transverse sinuses. CONCLUSION: Careful examination of the confluence of the sinuses is essential for the preoperative evaluation of posterior cranial fossa lesions and interventional procedures using the venous route.