Although environmental lead exposure is associated with significant deficits in cognition, executive functions, social behaviors, and motor abilities, the neuroanatomical basis for these impairments remains poorly understood. In this study, we examined the relationship between childhood lead exposure and adult brain volume using magnetic resonance imaging (MRI). We also explored how volume changes correlate with historic neuropsychological assessments. Volumetric analyses of whole brain MRI data revealed significant decreases in brain volume associated with childhood blood lead concentrations. Using conservative, minimum contiguous cluster size and statistical criteria (700 voxels, unadjusted p < 0.001), approximately 1.2% of the total gray matter was significantly and inversely associated with mean childhood blood lead concentration. The most affected regions included frontal gray matter, specifically the anterior cingulate cortex (ACC). Areas of lead-associated gray matter volume loss were much larger and more significant in men than women. We found that fine motor factor scores positively correlated with gray matter volume in the cerebellar hemispheres; adding blood lead concentrations as a variable to the model attenuated this correlation. Childhood lead exposure is associated with region-specific reductions in adult gray matter volume. Affected regions include the portions of the prefrontal cortex and ACC responsible for executive functions, mood regulation, and decision-making. These neuroanatomical findings were more pronounced for males, suggesting that lead-related atrophic changes have a disparate impact across sexes. This analysis suggests that adverse cognitive and behavioral outcomes may be related to lead's effect on brain development producing persistent alterations in structure. Using a simple model, we found that blood lead concentration mediates brain volume and fine motor function.

Objectives: The pathophysiology of sports-related concussion (SRC) is incompletely understood. Human adult and experimental animal investigations have revealed structural axonal injuries, decreases in the neuronal metabolite N-acetyl aspartate, and reduced cerebral blood flow (CBF) after SRC and minor traumatic brain injury. The authors of this investigation explore these possibilities after pediatric SRC.Patients And Methods: Twelve children, ages 11 to 15 years, who experienced SRC were evaluated by ImPACT neurocognitive testing, T1 and susceptibility weighted MRI, diffusion tensor imaging, proton magnetic resonance spectroscopy, and phase contrast angiography at 30 days after SRC.Conclusions: Pediatric SRC is primarily a physiologic injury, affecting CBF significantly without evidence of measurable structural, metabolic neuronal or axonal injury. Further study of CBF mechanisms is needed to explain patterns of recovery.

To assess the clinical usefulness of spatially localized hydrogen-1 magnetic resonance (MR) spectroscopy in distinguishing benign from malignant lesions on the basis of total choline levels. These studies were performed at 1.5 T with a four-channel multicoil that compresses the breast sagittally. Contrast material-enhanced MR imaging and single-voxel H-1 MR spectroscopy were performed in 17 patients (age range, 25-68 years) who had nonspecific mammographic findings. Histopathologic correlations were made from biopsy or surgical specimens. Ten patients had various malignant breast lesions 1-4 cm in diameter, and seven patients had benign processes. Most studies were performed with nominal voxel sizes (< 2 cm3). Spectra obtained with an echo time of 31 msec showed resonances from water and mobile fatty acids and, in some cases, the N-trimethyl resonance of choline-containing compounds (Cho) at 3.2 ppm. The absolute concentration of Cho in each lesion was determined with a phantom containing 1 mmol/L Cho as an external reference. On the basis of reference measurements, the least detectable level of Cho was 0.2 mmol/L. With this threshold, seven of 10 malignant lesions showed detectable levels of Cho. In contrast, Cho was seen in only one patient with an extremely rare benign process, a tubular adenoma. The remaining six patients with benign processes demonstrated no detectable Cho levels. Spatially localized H-1 MR spectroscopy can provide sufficient sensitivity and spectral resolution at 1.5 T to demonstrate Cho in human breast lesions with a spectroscopic protocol that provides up to 1-cm3 resolution. Determining the presence of Cho may provide a useful test for malignancy.