Management of children with high flow arteriovenous shunts of the brain is among the most challenging areas in modern medicine. Intracranial arteriovenous shunts (AVS) in children differ considerably from those seen in adults, in whom brain arteriovenous malformations (AVMs) and acquired dural arteriovenous fistulae predominate. These differences are seen both in the types of lesion and in their effects. In the neonatal and infantile age groups, the most common type of AVS is the vein of Galen aneurysmal malformation (VGAM), which has a male-to-female ratio of 3:1. Progressing further into childhood, dural malformations and brain arteriovenous malformations become more common.1 The consequences of an AVS in the developing brain are different from those in an adult, principally because of the immature cerebral venous system: the arachnoid granulations by which cerebrospinal fluid will be returned to the cerebral venous sinuses are not fully matured until 16-18 months of age.2 In infancy, cerebrospinal fluid is reabsorbed across the ventricular ependyma and brain parenchyma into the medullary veins. The presence of a large AVS such as a VGAM may raise venous sinus pressure, which is transmitted in turn to the cortical and finally the medullary veins. This will result in water congestion of the brain parenchyma, and impaired oxygenation leading to subependymal atrophy and in severe cases a progressive "melting brain syndrome". 3 The most common presentation of VGAM results from the size of the shunt itself, imposing elevated preload on the right side of the heart leading to cardiac failure. This may progress to multisystem failure. Haemorrhage in children with VGAMs is rare. 4 These are rare lesions and experience in their management has been restricted generally to large paediatric centres where a close collaboration between neuroradiologists, neonatologists, paediatric cardiologists, and neurologists has been achieved. Foremost among these centres has been Bicetre Hospital in Paris where Professor Pierre Lasjaunias' group has done much to clarify the nature of the disease and its appropriate management. A typical neurosciences unit serving a population of about three million could expect approximately one new VGAM patient a year. The aetiology of VGAMs is unknown; however, an early insult, perhaps resulting in a somatic mutation in neural crest and/or adjacent cephalic mesoderm in the early embryo, could be expected to cause such vascular abnormalities. 5 c ANATOMY OF VGAMThe VGAM is a rare and dramatic form of embryonic arteriovenous shunt located in the midline in the choroidal fissure. It consists of multiple feeding arteries, principally the anterior and posterior choroidal arteries and the anterior cerebral artery (following the cingulate gyrus and representing the embryonic limbic arterial arch), draining directly into an enlarged venous pouch (fig 1). This usually grossly dilated vein was recognised by Raybaud and colleagues to be the embryonic precursor of the vein of Galen-the median vein of the prosence...

The most common unusual pattern of spinal TB is skip lesions (11.5%). The distribution of this pattern is statistically significant as an important MRI feature for defining unusual spinal TB.

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Background:To compare diagnostic accuracy between DWI visual scale assessment and ADC value measurement of solid portion of the tumor in grading gliomas. Methods: This retrospective study included 38 patients who had pathologically proven gliomas between January 2013 and August 2018 with 18 low grade and 20 high grade tumors. All patients underwent MRI and biopsy. Two readers reviewed DWI visual scale independently. Disagreement was resolved by consensus. One reviewer measured ADC value of entire solid part of the tumor in single axial slice with greatest dimension of tumor which was chosen by consensus. Two data sets of visual scale and ADC value were analyzed and comparison of diagnostic accuracy in glioma grading was done by using area under the curve (AUC) of receiver operating characteristic curve (ROC). Results: Visual scale and ADC value could be used to distinguish between low and high grade gliomas with a statistically significant difference. (P-value 0.002 and <0.001). Almost all high grade gliomas had visual scale 5. The sensitivity, specificity, PPV NPV and accuracy were 50%, 100%, 100% , 64.3%,73.68% respectively. The cutoff level for the ADC value was determined to be 1119.48 x10 -6 mm 2 /s in differentiation between low and high grade gliomas with the sensitivity, specificity, PPV, NPV, accuracy of 90%, 88.89% , 90%, 88.9% and 89.47% respectively. There was no statistically significant difference(P-value = 0.163). Conclusion: Both Visual scale and ADC value were capable of differentiating between low and high grade gliomas. Although visual scale may not replace ADC measurement, larger scale prospective study is needed for validate this initial result.

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