Rana Patir

Complications related to pre-craniotomy shunts in posterior fossa tumours.

Among 344 patients with posterior fossa tumours treated from 1979 to 1986 a ventriculoperitoneal, or, less commonly, a ventriculatrial shunt was inserted in 164 cases pre-operatively. Haematoma following the insertion of a shunt was found to be an important cause of deterioration. While the occurrence of cerebrospinal fluid leak (p less than 0.3) and pseudomeningocele (p less than 0.01) was more frequent in the non-shunted cases, seizures (p less than 0.01) were found to occur more frequently in the shunted cases.

Imaging appearances of meningeal melanocytoma.

Meningeal melanocytoma is an uncommon, benign melanocytic tumour of the meninges. Only 15 cases have been reported to date. We present the MR and CT appearance of a case of compressive myelopathy due to cervical meningeal melanocytoma. Careful analysis of the imaging features, as illustrated in the present case, allows a preoperative diagnosis. The differential diagnosis includes malignant melanoma and melanocytic meningioma.

Application of a Far-Lateral Approach to the Subaxial Spine: Application, Technical Difficulties, and Results

OBJECTIVE The far-lateral approach has traditionally been used as an approach to ventral foramen magnum pathologies. Ventral pathologies in the cervical spine and cervicodorsal regions also provide unique surgical challenges. Traditional posterior surgical approaches to the ventral cervical pathologies require significant cord retraction, and anterior approaches require significant bone removal with implant stabilization. We approached these lesions using a modification of the far-lateral approach for lesions in the subaxial spine. METHODS Four patients underwent operations using this approach for ventral intradural pathologies in the subaxial spine. Two of the patients had recurrence of the lesions and underwent previous operations using a traditional midline approach. RESULTS All 4 patients underwent operations using this approach. This provided a unique view of the ventral pathologies and a scarless field in recurrent cases. All 4 patients improved neurologically after the surgery and had no deterioration or complications related to the surgery. CONCLUSION We propose extension of far-lateral approach to ventral intradural extramedullary lesions in the subaxial spine up to the cervicothoracic junction. The far-lateral approach can be extended safely to the ventral and ventrolateral lesions of the subaxial cervical spine, especially for recurrent or residual lesions previously approached from the midline posteriorly.

Diagnostic accuracy of automatic normalization of CBV in glioma grading using T1- weighted DCE-MRI

PURPOSE Aim of this retrospective study was to compare diagnostic accuracy of proposed automatic normalization method to quantify the relative cerebral blood volume (rCBV) with existing contra-lateral region of interest (ROI) based CBV normalization method for glioma grading using T1-weighted dynamic contrast enhanced MRI (DCE-MRI). MATERIAL AND METHODS Sixty patients with histologically confirmed gliomas were included in this study retrospectively. CBV maps were generated using T1-weighted DCE-MRI and are normalized by contralateral ROI based method (rCBV_contra), unaffected white matter (rCBV_WM) and unaffected gray matter (rCBV_GM), the latter two of these were generated automatically. An expert radiologist with >10years of experience in DCE-MRI and a non-expert with one year experience were used independently to measure rCBVs. Cutoff values for glioma grading were decided from ROC analysis. Agreement of histology with rCBV_WM, rCBV_GM and rCBV_contra respectively was studied using Kappa statistics and intra-class correlation coefficient (ICC). RESULT The diagnostic accuracy of glioma grading using the measured rCBV_contra by expert radiologist was found to be high (sensitivity=1.00, specificity=0.96, p<0.001) compared to the non-expert user (sensitivity=0.65, specificity=0.78, p<0.001). On the other hand, both the expert and non-expert user showed similar diagnostic accuracy for automatic rCBV_WM (sensitivity=0.89, specificity=0.87, p=0.001) and rCBV_GM (sensitivity=0.81, specificity=0.78, p=0.001) measures. Further, it was also observed that, contralateral based method by expert user showed highest agreement with histological grading of tumor (kappa=0.96, agreement 98.33%, p<0.001), however; automatic normalization method showed same percentage of agreement for both expert and non-expert user. rCBV_WM showed an agreement of 88.33% (kappa=0.76,p<0.001) with histopathological grading. CONCLUSION It was inferred from this study that, in the absence of expert user, automated normalization of CBV using the proposed method could provide better diagnostic accuracy compared to the manual contralateral based approach.

Primary intraosseous paraganglioma of the sacrum

Primary intraosseous sacral paraganglioma is a rare case of location for spinal paragangliomas, which generally manifest as intradural extramedullary tumors of the cauda equina region. The diagnosis can be elusive considering the rarity of sacral paragangliomas. The clinical importance of recognizing this relatively benign tumor cannot be overemphasized as the outcome, extent of surgery and management differs significantly from other common bony sacral tumors which are generally malignant. We report a rare case of sacral paraganglioma that was diagnosed only after histopathological examination, along with a relevant review of the literature.

Advanced and amplified BOLD fluctuations in high-grade gliomas: BOLD Fluctuations in Gliomas

Glioma grade along with patients age and general health are used for treatment planning and prognosis.

Role of Dynamic Contrast-Enhanced Perfusion Magnetic Resonance Imaging in Grading of Pediatric Brain Tumors on 3T

Background/Aims: Perfusion magnetic resonance imaging (MRI) is useful for preoperative assessment of brain tumors. Dynamic susceptibility contrast perfusion MRI is commonly used for evaluation of brain tumors. Dynamic contrast-enhanced (DCE) MRI is an alternative method that has mainly been used in adult brain tumors. In this preliminary study, we report our initial experience with the DCE perfusion MRI in pediatric brain tumors. Methods: Sixty-four newly diagnosed pediatric brain tumor patients underwent DCE perfusion MRI on a 3-T scanner. Hemodynamic and kinetic parametric maps were generated and the regions with the highest values were measured on each map. Statistical differences were sought to differentiate between low-grade tumors, high-grade tumors, and medulloblastomas. The perfusion metrics of common posterior fossa tumors were also compared. Results: Relative corrected cerebral blood volume (rCBV) and fractional plasma volume measures differed significantly between high- and low-grade tumors (p < 0.05). High-grade tumors could be differentiated from low-grade tumors, with an rCBV cutoff value of 2.41 and 88.6% sensitivity and 65% specificity. There was no significant difference in Ktrans, Kep, Ve, or λtr between these 2 groups of tumors. rCBV, relative quantification of the cerebral blood flow, and permeability indices were found to be significantly different in various posterior fossa tumors, i.e., pilocytic astrocytoma, ependymoma, and medulloblastoma (p < 0.05). Conclusion: DCE-derived perfusion metrics are useful in differentiating high-grade tumors from low-grade ones and discriminating among various posterior fossa tumors in the pediatric age group.

Comparison of actual with default hematocrit value in dynamic contrast enhanced MR perfusion quantification in grading of human glioma

PURPOSE Dynamic contrast enhanced (DCE) MRI is used to grade and to monitor the progression of glioma while on treatment. Usually, a fixed hematocrit (Hct) value for adults is assumed to be ~45%; however, it is actually known for individual variations. Purpose of this study was to investigate the effect of measured Hct values in glioma grading using DCE-MRI. MATERIALS AND METHODS Fifty glioma patients were included in this study. Kinetic and hemodynamic parameters were estimated for each patient using assumed as well as measured Hct values. To look the changes in Hct value over time, Hct was measured multiple times from 10 of these glioma patients who were on treatment. Simulation was done to look for the effect of extreme variations of Hct values on perfusion metrics. The data was compared to look for significant differences in the perfusion metrics derived from assumed and measured Hct values. RESULTS The measured Hct value in patients was found to be (40.4±4.28)%. The sensitivity and specificity of DCE-MRI parameters in glioma grading were not significantly influenced by using measured vis-a-vis assumed Hct values. The serial Hct values from 10 patients who were on treatment showed a fluctuation of 15-20% over time. The simulated data showed linear influence of Hct values on kinetic parameters. The tumor grading was altered on altering the Hct values in borderline cases. CONCLUSION Hct values influence the hemodynamic and kinetic metrics linearly and may affect glioma grading. However, perfusion metrics values might change significantly with large change in Hct values, especially in patients who are on chemotherapy necessitating its use in the DCE model.

Syringe Port: A Convenient, Safe, and Cost-Effective Tubular Retractor for Transportal Removal of Deep-Seated Lesions of the Brain

OBJECTIVE Minimally invasive transportal resection of deep intracranial lesions has become a widely accepted surgical technique. Many disposable, mountable port systems are available in the market for this purpose, like the ViewSite Brain Access System. The objective of this study was to find a cost-effective substitute for these systems. METHODS Deep-seated brain lesions were treated with a port system made from disposable syringes. The syringe port could be inserted through minicraniotomies placed and planned with navigation. All deep-seated lesions like ventricular tumours, colloid cysts, deep-seated gliomas, and basal ganglia hemorrhages were treated with this syringe port system and evaluated for safety, operative site hematomas, and blood loss. RESULTS 62 patients were operated on during the study period from January 2015 to July 2017, using this innovative syringe port system for deep-seated lesions of the brain. No operative site hematoma or contusions were seen along the port entry site and tract. CONCLUSIONS Syringe port is a cost-effective and safe alternative to the costly disposable brain port systems, especially for neurosurgical setups in developing countries for minimally invasive transportal resection of deep brain lesions.

Role of preoperative imaging in the diagnosis of primary diffuse craniospinal leptomeningeal gliomatosis

We present an unusual case of primary diffuse craniospinal leptomeningeal gliomatosis (PGDL), who was initially diagnosed on the basis of imaging, laboratory findings, and cranial meningeal biopsy as tuberculous meningitis and showed clinical deterioration while on anti-tuberculous treatment for 2 months. The patient was subsequently correctly diagnosed on diffusion weighted and post-contrast T1-weighted imaging of the craniospinal axis along with whole body imaging. The radiological findings were confirmed on histopathology and immunohistochemistry performed from the previous block as well as biopsy from the nodular mass in the lumbosacral meninges. We conclude that peroperative imaging may help in pinpointing the correct diagnosis and assist in guiding the surgeon to the site of biopsy.