Diffusion tensor imaging and proton magnetic resonance spectroscopy in brain tumor Correlation between structure and metabolism

Proton magnetic resonance spectroscopy and diffusion tensor imaging are non-invasive techniques used to detect metabolites and water diffusion in vivo. Previous studies have confirmed a positive correlation of individual fractional anisotropy values with N-acetylaspartate/creatine and N-acetylaspartate/choline ratios in tumors, edema, and normal white matter. This study divided the brain parenchyma into tumor, pedtumoral edema, and normal-appearing white matter according to MRI data, and analyzed the correlation of metabolites with water molecular diffusion. Results demonstrated that in normal-appearing white matter, N-acetylaspartate/creatine ratios were positively correlated with fractional anisotropy values, negatively correlated with radial diffusivities, and positively correlated with maximum eigenvalues. Maximum eigenvalues and radial diffusivities in peritumoral edema showed a negative correlation with choline, N-acetylaspartate, and creatine. Radial diffusivities in tumor demonstrated a negative correlation with choline. These data suggest that the relationship between metabolism and structure is markedly changed from normal white matter to peritumoral edema and tumor. Neural metabolism in the peritumoral edema area decreased with expanding extracellular space. The normal relationship of neural function and microstructure disappeared in the tumor region.

Langerhans cell histiocytosis presenting as an isolated brain tumour:A case report

Langerhans cell histiocytosis(LCH)is a rare proliferative histiocyte disorder.It can affect any organ or system,especially the bone,skin,lung,and central nervous system(CNS).In the CNS,the hypothalamic-pituitary is predominantly affected,whereas the brain parenchyma is rarely affected.LCH occurring in the brain parenchyma can be easily confused with glioblastoma or brain metastases.Thus,multimodal imaging is useful for the differential diagnosis of these intracerebral lesions and detection of lesions in the other organs.CASE SUMMARY A 47-year-old man presented with a headache for one week and sudden syncope.Brain computed tomography(CT)and magnetic resonance imaging showed an irregularly shaped nodule with heterogeneous enhancement.On^(18)F-fluorodeoxyglucose(^(18)F-FDG)positron emission tomography/CT,a nodule with^(18)F-FDG uptake and multiple cysts in the upper lobes of both lungs were noted,which was also confirmed by high-resolution CT.Thus,the patient underwent surgical resection of the brain lesion for further examination.Postoperative pathology confirmed LCH.The patient received chemotherapy after surgery.No recurrence was observed in the brain at the 12-mo follow-up.CONCLUSION Multimodal imaging is useful for evaluating the systemic condition of LCH,developing treatment plans,and designing post-treatment strategies.

MRI Features of Intracranial Primitive Neuroectodermal Tumors in Adults:Comparing with Histopathological Findings

The MRI appearances of 7 adult patients with pathologically proven intracranial primitive neuroectodermal tumors (PNET) were retrospectively analyzed. The MRI features were compared with findings in pathology and surgery. In this group, the tumor masses were most commonly found in the semisphere of cerebrum and in the vermis of cerebellum. They were relatively large and 4 were in lobulated shape. All of them had well defined margins. MR images showed the tumors to be mildly or obviously hypointense on T 1 weighted images and hyperintense on T 2 weighted images. Most masses had heterogeneous appearances with some cystic and necrotic areas. Intratumoral haemorrhage and focal calcification were occasionally seen. Mostly, there was no or only mild surrounding edema. Marked inhomogeneous contrast enhancement on MRI was seen in 6 cases except one. Two patients with multiple intracranial metastases were revealed on MR images. In this series, there was good correlation between MRI features and findings in pathology and surgery. These results showed that certain MRI features might suggest the diagnosis of intracranial PNET in adults. MRI is an effective technique to detect these tumors and is helpful to treatment planning and follow up.

Magnetic resonance imaging characteristics of postoperative intracranial dissemination of recurrent gliomas

Ten intracranial gliomas cases, that had postoperative intracranial dissemination, underwent magnetic resonance imaging （MRI） examinations, including T1 weighted imaging, fat-suppressed T1 weighted imaging, T2 weighted imaging and fluid attenuated inversion recovery （FLAIR）. Results showed that tumor metastasis had occurred via the cerebrospinal fluid, the brain white matter fibers and the surgical access site alone. On the plain MRI scans, 1/7 cases were linearly thickened with isointensity and 5/7 cases exhibited nodular foci on T1 weighted imaging; the cerebral sulci and cisterns in 2/7 cases had become shallow and five cases had nodular foci on T2 weighted imaging. FLAIR imaging revealed that the cerebral sulci and cisterns in 2/7 cases had become shallow and that six cases had affected nodular foci. The contrast-enhanced MRI scans revealed linear thickening in seven cases, nodules in seven cases, similarities to ＂mould-like＂ signs in six cases and hydrocephalus in six cases. These findings suggested that MRI with different sequences can diagnose glioma metastasis.

Multiple cerebral lesions in a patient with refractory celiac disease:A case report

BACKGROUND Enteropathy-associated T cell lymphoma(EATL)is an aggressive intestinal T cell lymphoma derived from intraepithelial lymphocytes,which occurs in individuals with celiac disease(CD).Cerebral involvement is an extremely rare condition and as described so far,lymphoma lesions may present as parenchymal predominantly supratentorial or leptomeningeal involvement.We describe a case of EATL with multifocal supra-and infratentorial brain involvement in a patient with refractory celiac disease(RCD).CASE SUMMARY A 58-years old man with known CD developed ulcerative jejunitis and was diagnosed with RCD type II.Six months later he presented with subacute cerebellar symptoms(gait ataxia,double vision,dizziness).Cranial magnetic resonance imaging(MRI)revealed multifocal T2 hyperintense supra-and infratentorial lesions.Laboratory studies of blood and cerebrospinal fluid were inconspicuous for infectious,inflammatory or autoimmune diseases.18Ffluorodeoxyglucose-positron emission tomography/computed tomography(18FDG-PET/CT)scan showed a suspect hypermetabolic lesion in the left upper abdomen and consequent surgical jejunal resection revealed the diagnosis of EATL.During the diagnostic work-up,neurological symptoms aggravated and evolved refractory to high-dosage cortisone.Recurrent MRI scans showed progressive cerebral lesions,highly suspicious for lymphoma and methotrexate chemotherapy was initiated.Unfortunately,clinically the patient responded only transiently.Finally,cerebral biopsy confirmed the diagnosis of cerebral involvement of EATL.Considering the poor prognosis and deterioration of the performance status,best supportive care was started.The patient passed away three weeks after diagnosis.CONCLUSION EATL with cerebral involvement must be considered as a possible differential diagnosis in patients with known RCD presenting with neurological symptoms.

Development of a rat C6 brain tumor model

OBJECTIVE: To establish rat C6 brain-tumor models and find a simple reliable index to judge tumor volume. METHODS: C6 cell suspension (10 microl) containing 10 g/L agarose and 1 x 10(6) cells was injected into the right caudate nucleus of the rat brain by a stereotaxic method. After implantation, rats were observed and given MRI scans. Rats were perfused with paraformaldehyde trans-aorta at the 10th, 15th, 20th and 25th day and before natural death. All brains, lungs, spinal cords and tumors were sectioned and inspected. Tumor-containing samples were prepared histologically by hematoxylin and eosin (HE) stains. RESULTS: Fifty implanted rats had 100% yield of intracerebral growth, with distant metastasis of 0% to 4%. CONCLUSION: A rat C6 brain-tumor model was successfully established. Rat survival time is correlated with tumor volume and may be useful as an index of tumor size.

Pleomorphic xanthoastrocytoma in the lateral ventricle with extensive subarachnoid dissemination： report of a case and review of the literature

Pleomorphic xanthoastrocytoma （PXA） is a rare benign tumor that is usually located in the superficial cerebral hemisphere.Most reports of PXAs have included only a single case or small series.Therefore,the data with respect to the natural history of this tumor are fragmentary.We report a case of a PXA in the unusual location of the right lateral ventricle with extensive subarachnoid dissemination.To our knowledge,this is a rare case of PXA in the lateral ventricle.In addition,extensive subarachnoid space dissemination of this distinctly benign type of glioma is exceedingly rare.In our case,there was meningeal dissemination and metastases to the bilateral trigeminal nerves and oculomotor nerves.The neuroradiographic features,tumor location,and dissemination were reviewed.

ntraoperative ultrasound assistance in the resection of small, leep-seated, or ill-defined intracerebral lesions

Background Intraoperative ultrasound （IOUS） has been procedures. In this study, we aimed to evaluate the potential the resection of small, deep-seated, or ill-defined lesions. ncreasingly used as a guiding tool during neurosurgical application of intraoperative ultrasound assisted surgery in Methods Eighty-six consecutive patients with small, deep-seated, or ill-defined intracerebral lesions were studied prospectively. An improved intraoperative imaging technique and surgical setup were practiced during the surgery. IOUS was performed in three orthogonal imaging planes （horizontal, coronal and sagittal）. Results Histopathological diagnoses of these 86 cases included cavernomas, metastases, hemangioblastomas, gliomas, and radiation necrosis. Forty-seven of the 86 lesions （54.7%） were small and deep-seated, 34/86 （39.5%） were ill-defined, and 5/86 （5.8%） were small, deep-seated, and ill-defined. Sonograms in the horizontal plane were obtained in all 86 cases. Sonograms in the sagittal plane and in the coronal plane were obtained only in 52 cases and in 46 cases, respectively, due to technical limitation. In 13 cases, sonograms in all three orthogonal planes were available. All lesions were successfully identified and localized by IOUS. Total resection was performed in 67 lesions （77.9%） and partial resection was performed in 19 lesions （22.1%）. Conclusions We propose IOUS to be performed in three orthogonal planes when surgery is planned for small, deep-seated, or ill-defined brain lesions. By applying this simple, improved technique, surgeons can perform resection of these lesions precisely.

功能磁共振成像/弥散张量成像图像融合:脑肿瘤治疗术前计划新方法(英文)

Objective To develop and test an image fusion software(fDf,fMRI/DTI fusion) which can overlap the anatomical(T1WI images),functional MRI(fMRI) and diffusion tensor imaging(DTI) simultaneously for preoperational evaluation of patients′ tumor.Methods fMRI with bilateral hands grasp movement and DTI were performed using GE 1.5 T magnetic resonance system on 10 subjects(5 healthy volunteers and 5 patients with brain tumor,of which 3 were metastases,1 was cavernous hemangioma and 1 was glioma).All data were input to the personal computer and offline postprocessing of fMRI and DTI data was performed using SPM5 and VolumeOne software package to visualize the activated functional cortex areas and corticospinal tracts.fDf was used to import the fMRI and structural images to VolumeOne to show them simultaneously.Results Brain functional activation maps and diffusion tensor fiber tracking images were obtained in all five healthy volunteers and four patients except one who suffered from left hemiplegia.The functional activation maps and the fiber tracking images were successfully fused by the fDf software,where the activations areas and the white matter fiber were displayed together.The fusion images of healthy volunteers showed the hand motion areas and corresponding corticospinal tracts,while that of the patients display the relationship of the eloquent cortex and peritumoral fiber tracts,which were useful in guiding the treatments for the surgeons and radiotherapists.It only took hours to present the fused images to the neurosurgeons or the radiotherapists.Conclusions All the results confirm that the image fusion software work well for all the data.It is an easy,free and fast way to realize the image fusion.The neurosurgeon and radiotherapist consider the software were very helpful for preoperative planning.