T1ρ demonstrates changes related to the processes of normal aging.

Participation in contact sports places athletes at elevated risk for repeated head injuries and is associated with negative mental health outcomes later in life. The current study identified changes observable on neuroimaging that persisted beyond the apparent resolution of acute symptoms of concussion. Sixteen young adult ice hockey players with a remote history of concussion but no subjective complaints were compared against 13 of their teammates with no history of concussion. Participants completed a detailed phenotypic assessment and a neuroimaging battery including diffusion kurtosis imaging and resting-state functional magnetic resonance imaging. Athletes with a history of concussion performed no differently from those without on phenotypic assessment, but showed significantly elevated fractional anisotropy (FA) in the left genu and anterior corona radiata relative to those without. Post hoc analyses revealed that elevated FA was associated with increased microstructural complexity perpendicular to the primary axon (radial kurtosis). Athletes with concussion history also showed significant differences in the organization of the default mode network (DMN) characterized by stronger temporal coherence in posterior DMN, decreased temporal coherence in anterior DMN, and increased functional connectivity outside the DMN. In the absence of deficits on detailed phenotypic assessment, athletes with a history of concussion displayed changes to the microstructural architecture of the cerebral white matter and to the functional connectivity of the brain at rest. Some of these changes are consistent with those previously associated with persisting deficits and complaints, but we also report novel, complementary changes that possibly represent compensatory mechanisms.

T1ρ MRI demonstrates enhanced lesion contrast compared with T2 , and in some cases may provide complementary information. T1ρ may provide a useful measure of demyelinating processes in MS.

The methods described enable routine DTI and tractography of the lower spinal cord at 3 T. Compared with conventional imaging, tractography offers additional information that may prove useful in the characterization and surgical planning for congenital lesions involving the lower spinal cord.

Background/Aims: As a preoperative planning tool, conventional magnetic resonance (MR) imaging may have limited value in differentiating tumors from white matter tracts. MR diffusion tensor imaging (MRDTI) has become a useful tool for evaluating white matter tracts in relation to surrounding structures and has been used in surgical planning for brain tumors involving white matter. We investigated the use of DTI of the optic nerves in surgical planning for pediatric suprasellar tumors. Methods: We present findings in 10 pediatric control patients and 2 cases of pediatric suprasellar tumors in which a routine 6-direction DTI of the brain was performed at 3 T. Postprocessing permitted the study of the diffusion tensor parameters, as well as the tractography, of the optic nerves. Results: The control patients demonstrated the optimization of the technique and permitted the quantitation of fractional anisotropy and apparent diffusion coefficient values. The tumor cases demonstrated the utility of optic nerve DTI to differentiate between optic nerves and suprasellar/chiasmatic brain tumors. Conclusions: A routine 6-direction DTI of the pediatric brain at 3 T permits a detailed DTI study of the optic nerves. Optic nerve tractography can be used to aid in the evaluation and treatment of pediatric brain tumors in the area of the optic chiasm.