Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · May 2003
ReviewNeuroimaging in Alzheimer disease: an evidence-based review.
Current clinical criteria (DSM-IIIR and NINCDS-ADRDA) for the diagnosis of dementia and AD are reliable; however, these criteria remain to be validated by clinicians of different levels of expertise at different clinical settings. Structural neuroimaging has an important role in initial evaluation of dementia for ruling out potentially treatable causes. Although CT is the appropriate choice when brain tumors, subdural hematoma, or normal pressure hydrocephalus is suspected, MR imaging is more sensitive to the white-matter changes in vascular dementia. ⋯ These neuroimaging markers may be useful for monitoring symptomatic progression in groups of patients with AD for drug trials. Furthermore, antemortem MR-based hippocampal volumes correlate with the pathologic stage of AD, and the rate of hippocampal volume loss on MR imaging correlates with clinical disease progression in the cognitive continuum from normal aging to MCI and to AD. Hence, as an in vivo correlate of pathologic involvement, structural imaging measures are potential surrogate markers for disease progression in patients with established AD and in patients with prodromal AD, who will benefit most from disease-modifying therapies underway.
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Neuroimaging Clin. N. Am. · May 2003
ReviewAdults and children with headache: evidence-based diagnostic evaluation.
Headache represents one of the most common complaints in the outpatient and emergency room setting [1]. Most causes of headache are benign and do not require emergent imaging or intervention. The authors' review of the diagnostic tests does not offer absolute indications for neuroimaging because most of the evidence is based on studies that are not randomized controlled trials. ⋯ In high-risk patients, MR imaging is the test of choice whereas in low-risk patients, close clinical observation with periodic reassessment is the best strategy [44]. Clinical diagnosis will always play a key role in the evaluation of headache disorders; however, for the small subset of patients who present with headache secondary to an intracranial space-occupying lesion, bleeding, or SAH, making the diagnosis is crucial to decreasing morbidity and mortality. CT, MR imaging, and lumbar puncture play important roles in the assessment of headache disorders, but their future roles will continue to evolve as the technology becomes more sophisticated and robust, and physicians become more expert with their use [1].
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Neuroimaging Clin. N. Am. · May 2003
ReviewAmyotrophic lateral sclerosis and primary lateral sclerosis: evidence-based diagnostic evaluation of the upper motor neuron.
Magnetic resonance imaging and MR spectroscopy are important tools in the diagnostic evaluation of patients with suspected motor neuron disease. Further investigation is needed to determine and to compare the utility of various neuroimaging markers for diagnosis and disease progression [112]. Newer MR tools, such as diffusion tensor imaging, magnetization transfer imaging, and functional MR imaging, have substantial promise as scientific and clinical tools in this ongoing endeavor.
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Neuroimaging Clin. N. Am. · May 2003
ReviewSickle cell disease and stroke in a pediatric population. Evidence-based diagnostic evaluation.
Cerebrovascular complications are common in SCD and constitute a major source of concern to the pediatric hematologist. These complications can be either clinically overt or covert. ⋯ Imaging guidelines for children have emerged based on the available level 2 and 3 literature, however, CT and MR imaging remain the initial tests of choice for stroke assessment, and TCD is the imaging tool of choice for stroke prevention. Based on guidelines handed down from the NIH, TCD has become a part of routine continuing care of children with SCD.
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The imaging work-up of patients with acute neurologic deficits should begin with noncontrast CT to exclude intracerebral hemorrhage. Based on positive results from the NINDS t-PA trial, the overriding objectives of imaging in the selection of patients for t-PA treatment are the detection of hemorrhage and rapid evaluation (speed of imaging). ⋯ Clinical outcome data are lacking; therefore, the routine use of screening MR imaging before t-PA therapy is not supported. Rigorous validation and correlation to clinical outcomes will be required.