BACKGROUND AND PURPOSE: Synthetic MR imaging enables reconstruction of various image contrasts from 1 scan, reducing scan times and potentially providing novel information. This study is the first large, prospective comparison of synthetic-versus-conventional MR imaging for routine neuroimaging.

The American Academy of Neurology now recommends that all cases of cerebral palsy of unknown origin undergo neuroimaging. Controversy surrounds this recommendation because of concerns about the adequacy of the supporting evidence. This article reviews the evidence provided by magnetic resonance imaging (MRI) and computed tomography (CT) imaging studies in cerebral palsy and discusses the potential benefits of imaging, techniques in current use, and future directions, with a focus on improving etiologic understanding. Most (83%) children with cerebral palsy have abnormal neuroradiological findings, with white matter damage the most common abnormality. Combined gray and white matter abnormalities are more common among children with hemiplegia; isolated white matter abnormalities are more common with bilateral spasticity or athetosis, and with ataxia; isolated gray matter damage is the least common finding. About 10% of cerebral palsy is attributable to brain malformations, and 17% of cerebral palsy cases have no abnormality detectable by conventional MR or CT imaging. Although neuroimaging studies have increased our understanding of the abnormalities in brain development in cerebral palsy, they are less informative than they might be because of 4 common problems: (1) inappropriate assignment of etiology to morphologic findings, (2) inconsistent descriptions of radiologic findings, (3) uncertain relationship of pathologic findings to brain insult timing estimates, and (4) study designs that are not based on generalizable samples. Neuroimaging is not necessarily required for diagnosis of cerebral palsy because the disorder is based on clinical findings. The principal contribution of imaging is to the understanding of etiology and pathogenesis, including ruling in or out conditions that may have implications for genetic counseling, such as malformations. In the future, as more sophisticated imaging procedures are applied to cerebral palsy, specific morphologic findings may be linked to etiologic events or exposures, thus leading to potential pathways for prevention.

Previous studies show that transient increases in both blood flow and magnetic resonance image signal intensity (SI) occur in human muscle after brief, single contractions, and that the SI increases are threefold larger in physically active compared with sedentary subjects. This study examined the relationship between these transient changes by measuring anterior tibial artery flow (Doppler ultrasound), anterior muscle SI (3T, one-shot echo-planar images, TR/TE = 1,000/35), and muscle blood volume and hemoglobin saturation [near-infrared spectroscopy (NIRS)] in the same subjects after 1-s-duration maximum isometric ankle dorsiflexion contractions. Arterial flow increased to a peak 5.9 ± 0.7-fold above rest (SE, n = 11, range 2.6-10.2) within 7 s and muscle SI increased to a peak 2.7 ± 0.6% (range 0.0-6.0%) above rest within 12 s after the contractions. The peak postcontractile SI change was significantly correlated with both peak postcontractile flow (r = 0.61, n = 11) and with subject activity level (r = 0.63, n = 10) estimated from 7-day accelerometer recordings. In a subset of 7 subjects in which NIRS data acquisition was successful, the peak magnitude of the postcontractile SI change agreed well with SI calculated from the NIRS blood volume and saturation changes (r = 0.80, slope = 1.02, intercept = 0.16), confirming the blood-oxygenation-level-dependent (BOLD) mechanism underlying the SI change. The magnitudes of postcontractile changes in blood saturation and SI were reproduced by a simple one-compartment muscle vascular model that incorporated the observed pattern of postcontractile flow, and which assumed muscle O(2) consumption peaks within 2 s after a brief contraction. The results show that muscle postcontractile BOLD SI changes depend critically on the balance between O(2) delivery and O(2) consumption, both of which can be altered by chronic physical activity.

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Our initial hypothesis was not confirmed, in that there were findings that were confined to the symptomatic group of elite-level female gymnasts.

The cortical regions specialized in speech-language exhibit a left-right asymmetry, e.g., a larger cortical size in the left auditory cortex and Wernicke's area. The possibility of developmental asymmetry in axonal fibers interconnecting speech-language cortical areas can be investigated by in vivo diffusion tensor imaging. Fifteen right-handed native English speakers showed a markedly significant asymmetry (P < 0. 0005) in the relative anisotropy of water diffusion in the subinsular white matter, greater on the left. Additionally, the first principal diffusivity was greater and the second and third principal diffusivities were smaller on the left than right side. These results suggest the subinsular axonal structures developed differently between the left and right sides. A possible association between the hemispheric specialization in language and speech and the subinsular axonal fiber development is discussed.

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Thoracic radiculopathy represents an uncommon spinal disorder that is frequently overlooked in the evaluation of spinal pain syndromes. Degenerative disc disease and diabetes mellitus may frequently cause radiculopathy at the thoracic level. Electromyography and magnetic resonance imaging are useful in the evaluation of radiculopathy and thoracic spinal pain syndromes. Percutaneous vertebroplasty is a procedure that may be used in the treatment of thoracic spinal pain syndromes. Surgical intervention for thoracic radiculopathy usually is reserved for patients with progressive myelopathy and neurologic compromise.