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BACKGROUND AND PURPOSE: DWI has the potential to improve the detection and evaluation of spine and spinal cord pathologies. This study assessed whether a recently described method (rFOV DWI) adds diagnostic value in clinical patients.

While no singular neuroimaging feature is pathognomonic of PPTID, these tumors are usually larger, demonstrate local invasion, and appear much more heterogeneous than pineocytoma. Because PPTIDs have a higher grade and increased potential for recurrence as compared to pineocytomas, it is important to consider this diagnosis as shorter follow-up, and adjuvant therapy may be indicated in selected cases.

Pilomyxoid astrocytoma (PmA) is a recently identified tumor type characteristically located in the hypothalamus and occurring in young children (<2 y). PmAs were formerly included in large series of pilocytic astrocytomas (PA) until it was realized in 1999 that this differing phenotype tended to manifest a more aggressive biologic course. PmA is defined by its pathologic features of a monomorphous architectural pattern, abundant myxoid background, and absence of features seen in classic PA. We present 4 histologically definite cases of PmA seen at our institution over a minimum 5-year follow-up time: one was rapidly fatal after initial treatment and 2 recurred during therapy. No singular neuroimaging feature can reliably diagnose PmA. However, PmAs tend to be solid, are more commonly necrotic and show extension of abnormal signal intensity into adjacent structures. Cysts, calcification, and perilesional edema are more common in classic PA. Serial neuroimaging in PmA shows early progression of predominantly solid, and later progression of predominantly cystic component. Radiologists should consider this diagnosis particularly in young children with hypothalamic tumors that lack the typical cystic appearance seen in PA.

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Pilomyxoid astrocytomas (PmA) are tumors characteristically located in hypothalamus of young children that may manifest a more aggressive biological course than pilocytic astrocytoma (PA). PmAs rarely have been documented to show maturation over time to PA. We present 4 PmAs, one of which was rapidly fatal after initial treatment and two of which recurred during therapy. Close follow‐up over a minimum 5 year interval showed evolution in neuroimaging and histological features. By neuroimaging, PmAs tend to be solid and show extension of abnormal signal intensity into adjacent structures. Necrosis is more common with PmA, contrasting with the cysts, calcification, and perilesional edema that are more common in classic PA. In our series, neuroimaging showed early tumor progression of predominantly the solid component and later progression of predominantly the cystic component. One case demonstrated evolution of histological features from classic angiocentric PmA to Rosenthal fiber‐rich PA over a 7 year interval.

We present a case of right hemispheric dominance for sign language but left hemispheric dominance for reading, in a left-handed deaf patient with epilepsy and left mesial temporal sclerosis. Atypical language laterality for ASL was determined by preoperative fMRI, and congruent with ASL modified WADA testing. We conclude that reading and sign language can have crossed dominance and preoperative fMRI evaluation of deaf patients should include both reading and sign language evaluations.

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