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Apparent diffusion coefficients (ADC) were measured in a rat spinal cord weight-drop injury model. After sacrifice, the spinal cords were fixed in situ and excised for MR imaging and ADC measurement. Diffusion is anisotropic in normal gray and white matter. There were significant decreases in ADCs measured along the longitudinal axis of the injured cord and increases in ADCs measured transverse to the cord. Injured segments demonstrated reductions in diffusion anisotropy in the white matter. Diffusion was completely isotropic at the epicenter of the weight-drop injury. Significant decreases in longitudinal ADC and increases in transverse ADC were observed in portions of the cord which appeared normal on conventional spin-echo and calculated T2 images. Thus ADC measurement may complement routine imaging for evaluation of spinal cord injury.

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for the ELGAN Study Investigators abstract BACKGROUND AND OBJECTIVE: Despite reductions in mortality and morbidity among children born extremely preterm, they remain at high risk of neurocognitive deficits, with up to 40% having significant cognitive deficits at school age. We assessed the rate of neurocognitive impairment in a contemporary US cohort of 873 children aged 10 years who were born <28 weeks' gestation.

Objectives To evaluate whether in children born extremely preterm, indicators of sustained systemic inflammation in the first month of life are associated with cognitive impairment at school age. Study design 873 of 966 eligible children previously enrolled in the multicenter Extremely Low Gestational Age Newborn Study from 2002–2004 were evaluated at age 10 years. We analyzed the relationship between elevated blood concentrations of inflammation-associated proteins in the first 2 weeks (“early elevations”; n=812) and the 3rd and 4th week (“late elevations”; n=532) of life with neurocognition. Results Early elevations of CRP, TNF-alpha, IL-8, ICAM-1, and EPO were associated with IQ values >2 SD below the expected mean (ORs: 2.0–2.3) and with moderate to severe cognitive impairment on a composite measure of IQ and executive function (ORs: 2.1–3.6). Additionally, severe cognitive impairment was associated with late protein elevations of CRP (OR:4.0; 95% CI 1.5, 10), IL-8 (OR:5.0; 1.9, 13), ICAM-1 (OR:6.5; 2.6, 16), VEGF-R2 (OR:3.2; 1.2, 8.3), and TSH (OR:3.1; 1.3, 7.3). Moderate cognitive impairment was most strongly associated with elevations of IL-8, ICAM-1, and VEGF-R2. When four or more inflammatory proteins were elevated early, the risk of having an IQ<70 and having overall impaired cognitive ability was more than doubled (ORs:2.1–2.4); the presence of four or more inflammatory protein elevated late was strongly linked to adverse cognitive outcomes (ORs:2.9–4.8). Conclusion EP children who had sustained elevations of inflammation-related proteins in the first postnatal month are more likely than EP peers without such elevations to have cognitive impairment at 10 years.

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Objectives To compare the prevalence of cognitive, neurological, and behavioral outcomes at 10 years of age in 428 girls and 446 boys who were born extremely preterm (EP). Study design 889 of 966 eligible children previously enrolled in the multi-center Extremely Low Gestational Age Newborns (ELGAN) Study from 2002–2004 were evaluated at 10 years of age. Children underwent a neuropsychological battery and testing for autism spectrum disorder (ASD), and parents reported on their child’s behavior, development, and seizures. Results 28% of boys and 21% of girls exhibited moderate to severe impairment on summary measures of cognitive abilities. Boys had a higher prevalence of impairment than girls in nearly all measures of cognition, were more than twice as likely to have microcephaly (15% in boys, 8% in girls), and require more often assistive devices to ambulate (6% in boys, 4% in girls). In contrast, boys and girls had comparable risk for a history of seizure (identified in 10% of the cohort) or epilepsy (identified in 7% of the cohort). The boy-to-girl ratio of ASD (9% in boys, 5% in girls) was lower than expected compared with the overall US autism population. Conclusion In this contemporary cohort of children born extremely premature and evaluated at school age, boys had higher prevalence of cognitive, neurological, and behavioral deficits than girls. The ratio of boys to girls among those with ASD deserves further study as does the perinatal environmental- genetic interactions that might contribute to male preponderance of deficits in this high-risk sample.

Two conceptually related variable-flip-angle 3D spin-echo pulse sequences were designed for imaging at voxel sizes of 2-5 x 10(-3) mm3 corresponding to pixel areas of less than 100 x 100 microns2 and section thicknesses on the order of 300-400 microns on a conventional 1.5 T MR imaging system equipped with 1 G/cm imaging field gradients, providing 12 sections in 10 min imaging time. The pulse sequences make use of the concept of restoring longitudinal magnetization inverted by the 180 degrees phase reversal pulse and are derivatives of pulse sequences previously dubbed "FATE" and "RASEE." It is shown that even in the small-voxel regime (< 10(-2) mm3 voxel size) and at echo times on the order of 10 ms, gradient echo images are sensitive to intrinsic fields causing artifactual boundary effects, including signal loss from intravoxel phase scrambling and spatial mismapping. At this resolution the variable flip-angle spin-echo pulse sequences are demonstrated to be better suited for imaging magnetically heterogeneous systems such as trabecular bone microstructure in vivo. These pulse sequences are found to be substantially less sensitive to distortions from magnetic dipole fields occurring at the boundaries of two phases of different magnetic permeability.