Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Brain death determination (BDD) is primarily a clinical diagnosis, where death is defined as the permanent loss of brainstem function. In scenarios where clinical examinations are inaccurate, ancillary imaging tests are required. The choice of ancillary imaging test is variable, but the common denominator for all of them is to establish a lack of cerebral blood flow. The purpose of this study was to compare the diagnostic accuracy and interrater reliability of different ancillary imaging tests used for BDD. ⋯ The uses of ancillary imaging tests for BDD are increasing. Within this study's limitations, CTP followed by radionuclide scan were found to be the most accurate and reliable ancillary imaging test for BDD.
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The thalamus is a part of the diencephalon, containing numerous connections between the forebrain and subcortical structures. It serves an important function as a relay center between the cerebral cortex and the subcortical regions, particularly with sensory information. The thalamus also plays a major role in regulating arousal and the levels of awareness. ⋯ In addition, we will also review the variant thalamic territories and associated infarction syndromes of the anteromedian, central, and posterolateral territories. This review article is aimed to better the clinical and radiologic understanding as well as the diagnosis of classic and variant thalamic territory infarcts. This article will also briefly touch on the recovery of function after thalamic infarcts.
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Surgery is the first choice therapeutic approach in case of drug-resistant epilepsy. Unfortunately, up to 43% of patients referred for presurgical assessment do not have a lesion detectable by routine 3T magnetic resonance imaging (MRI) (MRI-negative), although most of them likely have an underlying epileptogenic lesion. Thus, new MRI modalities with increased sensibility for epileptogenic lesions are required. This paper describes the magnetization-prepared two rapid acquisition gradient echoes (MP2RAGE) and susceptibility-weighted imaging (SWI) findings at 7T in a series of patients with drug-resistant epilepsy of different etiologies. ⋯ MRI at ultra-high field is very promising for the detection of inconspicuous epileptogenic lesions and may facilitate epilepsy surgery of a great number of to-date MRI-negative patients.
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The purpose of this review is to provide an update on technology related to Transcranial Color Coded Doppler Examinations. Microvascularization (MicroV) is an emerging Power Doppler technology which can allow visualization of low and weak blood flows even at high depths, thus providing a suitable technique for transcranial ultrasound analysis. With MicroV, reconstruction of the vessel shape can be improved, without any overestimation. ⋯ In further neurosonology technology development efforts, attempts have been made to address morphology issues and overcome technical limitations. The use of contrast agents has helped in this regard by introducing harmonics and subtraction software, which allowed better morphological studies of vessels, due to their increased signal-to-noise ratio. Having no limitations in the learning curve, in time and contrast agent techniques, and due to its high signal-to-noise ratio, MicroV has shown great potential to obtain the best morphological definition.
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An imaging biomarker of myelin integrity is an unmet need in multiple sclerosis (MS). Selective inversion recovery (SIR) quantitative magnetization transfer imaging (qMT) provides assays of myelin content in the human brain. We previously translated the SIR method to 7T and incorporated a rapid turbo field echo (TFE) readout for whole-brain imaging within clinically acceptable scan times. We herein provide histological validation and test in vivo feasibility and applicability of the SIR-TFE protocol in MS. ⋯ SIR-qMT at 7T provides sensitive, quantitative measures of myelin integrity for clinical and research applications.