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Background and Purpose: Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation., Materials and Methods: A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects., Results: We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group., Conclusions: These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.

Background and Purpose: Deriving accurate language lateralization from fMRI studies in the clinical context can be difficult, with 10%-20% incorrect conclusions. Most interpretations are qualitative, performed by neuroimaging experts. Quantitative lateralization has been widely described but with little implementation in the clinical setting and is disadvantaged by the use of arbitrary threshold techniques. We investigated the application and utility of a nonthreshold CLI, in a clinical setting, as applied by a group of practicing neuroradiologists., Materials and Methods: Twenty-two patients with known language lateralization (11 left and 11 nonleft dominant) had their images reviewed by 8 neuroradiologists in 2 settings, all randomized, once by using a CLI and once without using a CLI. For each review, neuroradiologists recorded their impressions of lateralization for each language sequence, the overall lateralization conclusion, their impression of scan quality and noise, and the subjective confidence in their conclusion., Results: The inter-rater κ for lateralization was 0.64, which increased to 0.70 with the use of CLI. The group accuracy of overall lateralization was 78%, which increased to 81% with the use of a CLI. Using a CLI removed 2 instances of significant errors, with a neuroradiologist's impression of left lateralization in a patient with known right lateralization. Using a CLI had no effect on examinations with conclusions formed with either high confidence or no confidence., Conclusions: Although the overall clinical benefit of a CLI is modest, the most significant impact is to reduce the most harmful misclassification errors, particularly in fMRI examinations that are suboptimal.

Background and Purpose: DTI is an MR imaging measure of brain tissue integrity and provides an attractive metric for use in neuroprotection clinical trials. The purpose of our study was to use DTI to evaluate the longitudinal changes in brain tissue integrity in a group of patients with MS., Materials and Methods: Twenty-one patients with MS starting natalizumab were imaged serially for 12 months. Gadolinium-enhancing lesions and 20 regions of interest from normal-appearing white and gray matter brain tissue were followed longitudinally. Average values within each region of interest were derived for FA, λ(∥), λ(⊥), and MD. New T1 black holes were identified at 12 months. Analysis was performed by using mixed-model regression analysis with slope (ie, DTI change per month) as the dependent variable., Results: During 1 year, FA increased in gadolinium-enhancing lesions but decreased in NABT (P < .0001 for both). Changes in FA within gadolinium-enhancing lesions were driven by decreased λ(⊥) (P < .001), and within NABT, by decreased λ(∥) (P < .0001). A higher λ(⊥) within gadolinium-enhancing lesions at baseline predicted conversion to T1 black holes at 12 months. MD was unchanged in both gadolinium-enhancing lesions and NABT., Conclusions: We observed changes in DTI measures during 1 year in both gadolinium-enhancing lesions and NABT. The DTI results may represent possible remyelination within acute lesions and chronic axonal degeneration in NAWM. These results support the use of DTI as a measure of tissue integrity for studies of neuroprotective therapies.

Background and Purpose: A substantial number of clinical fMRI examinations inadequately assess language localization or lateralization, usually due to patient movement and suboptimal participation. We hypothesized that a prescan interview of the patient by the radiologist would reduce the fraction of nondiagnostic scans., Materials and Methods: A single noise score for each acquisition was produced from time-series data on the basis of a weighted sum of 22 factors. Scores were recorded as the following quartiles: 0-5 = excellent, 5-10 = adequate, 10-15= marginal, and >15 = unacceptable. This measure was evaluated for 202 consecutive fMRI patients: 96 without and 106 with a physician prescan interview. The data were analyzed to compute the fraction of all nondiagnostic sequences and entire studies and were compared between the 2 groups. Image-noise characteristics included the SDs of linear and angular displacements of the head and the number of time-series outliers caused by focal motion., Results: Of 999 sequences acquired, 539 had a prescan interview. The mean noise score significantly decreased for both individual sequence (from 7.9 to 6.3, P = <.001) and study-based (from 7.7 to 6.2, P = .05) methods. The fraction of sequences or studies scored as unacceptable decreased for sequence-based (from 15.2% to 10.9%, P = .04) and study-based (from 9.4% to 1.9%, P = .02) analyses. SDs of head motion decreased for linear (by 12%-14%, P < .01) and angular displacement (by 38%-48%, P < .001). The number of time-series spikes decreased by 10% (P = .004)., Conclusions: We report that a prescan physician-patient interview modestly but significantly reduces fMRI noise scores. These results support the newly added billable costs of professional intervention before fMRI scans.