BACKGROUND AND PURPOSE:CSM is a common neurologic disease that results in progressive disability and eventual paralysis without appropriate treatment. Imaging plays a significant role in the evaluation of CSM and has evolved with recent technical advances. We sought to systematically explore the relationship between clinical disease severity and DTI in CSM, and to investigate the potential use of DTI in surgical decision-making models.

Highly accelerated dynamic MRI using compressed sensing and parallel imaging provides accurate permeability modeling and enables full brain, high resolution acquisitions.

IntroductionMedical imaging now accounts for most of the US population's exposure to ionizing radiation. A substantial proportion of this medical imaging is ordered in the emergency setting. We aim to provide a general overview of radiation dose from medical imaging with a focus on computed tomography, as well as a literature review of recent efforts to decrease unnecessary radiation exposure to patients in the emergency department setting.MethodsWe conducted a literature review through calendar year 2010 for all published articles pertaining to the emergency department and radiation exposure.ResultsThe benefits of imaging usually outweigh the risks of eventual radiation-induced cancer in most clinical scenarios encountered by emergency physicians. However, our literature review identified 3 specific clinical situations in the general adult population in which the lifetime risks of cancer may outweigh the benefits to the patient: rule out pulmonary embolism, flank pain, and recurrent abdominal pain in inflammatory bowel disease. For these specific clinical scenarios, a physician-patient discussion about such risks and benefits may be warranted.ConclusionEmergency physicians, now at the front line of patients' exposure to ionizing radiation, should have a general understanding of the magnitude of radiation dose from advanced medical imaging procedures and their associated risks. Future areas of research should include the development of protocols and guidelines that limit unnecessary patient radiation exposure.

Fifty-one male and two female patients were divided into the following three groups: (a) patients with symptomatic carotid artery disease who received carotid endarterectomies, (b) patients with symptomatic carotid artery disease who either declined or were not candidates for carotid endarterectomies, and (c) patients who received a surgical procedure unrelated to cerebral functioning. The three groups were not significantly different in terms of age or educational level. The subjects were examined using the WAIS, Wechsler Memory Scale, Halstead-Reitan Neuropsychological Battery, Sickness Impact Profile, and Profile of Mood States. The assessments were conducted presurgery and repeated at a 6 month follow-up. The results of two-way analyses of variance revealed a significant trials effect for a majority of the variables, including the average impairment rating and the full scale WAIS IQ. However, significant group x trials interactions were not found for either the neuropsychological measures or the quality of life indices. The results did not support the conclusion of improved mental status or increased psychosocial well-being in patients who received carotid endarterectomies.

✓ Radiosurgery has proven useful in the treatment of small arteriovenous malformations (AVMs) of the brain. However, the volume of healthy tissue irradiated around large lesions is rather significant, necessitating reduced radiation doses to avoid complications. As a consequence, this can produce poorer obliteration rates. Several strategies have been developed in the past decade to circumvent dose–volume problems with large AVMs, including repeated treatments as well as dose, and volume fractionation schemes. Although success on par with that achieved in lesions smaller than 3 ml remains elusive, improvements over the obliteration rate, the complication rate or both have been reported after conventional single-dose stereotactic radiosurgery (SRS). Radiosurgery with a marginal dose or peripheral dose < 15 Gy rarely obliterates AVMs, yet most lesions diminish in size posttreatment. Higher doses may then be reapplied to any residual nidi after an appropriate follow-up period. Volume fractionation divides AVMs into smaller segments to be treated on separate occasions. Doses > 15 Gy irradiate target volumes of only 5–15 ml, thereby minimizing the radiation delivered to the surrounding brain tissue. Fewer adverse radiological effects with the use of fractionated radiosurgery over standard radiosurgery have been reported. Advances in AVM localization, dose delivery, and dosimetry have revived interest in hypofractionated SRS. Investigators dispensing ≥ 7 Gy per fraction minimum doses have achieved occlusion with an acceptable number of complications in 53–70% of patients. The extended latency period between treatment and occlusion, about 5 years for emerging techniques (such as salvage, staged volume, and hypofractionated radiotherapy), exposes the patient to the risk of hemorrhage during that period. Nevertheless, improvements in dose planning and target delineation will continue to improve the prognosis in patients harboring inoperable AVMs.