Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Despite accumulating evidence for the clinical efficacy and neuroprotective properties of rasagiline in Parkinson's disease (PD), effects of rasagiline on brain perfusion in PD patients have not been elucidated. The present study aimed to investigate the effects of rasagiline on regional cerebral blood flow (rCBF) in patients with PD using single-photon emission computed tomography (SPECT). ⋯ Our results show that adjunctive rasagiline treatment had beneficial effects on perfusion in the precuneus of PD patients, suggesting potential neuroprotective effects.
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HIV-positive subjects suffer from neurocognitive deficits and disorder. We employ multishell diffusion imaging to investigate possible white matter microstructural correlates of infection severity, quantified through plasmatic percentage value of CD4 T-lymphocytes, Nadir-CD4 count, and plasma concentration of human immunodeficiency virus (HIV)-ribonucleic acid (RNA). ⋯ In HIV-positive subjects, associations between biochemical and diffusion-MRI variables are found along the association fibers, which connect brain areas involved in memory formation, providing a possible interpretation for the neurobiological substrate underlying cognitive disturbances in HIV.
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Variations in the venous drainage of the central nervous system can have imaging and clinical findings that mimic pathology, presenting a challenge for neuroimagers and clinicians. Patients with these variants may undergo unnecessary testing, and patients with pathology may receive delayed diagnoses because of overlap with benign findings. Consequently, the accurate identification of venous variations on cross-sectional imaging and angiography and their potential causes are critical for differentiating benign imaging variants from potential pathologic processes requiring further evaluation. ⋯ In addition, some supposedly benign variations, such as the developmental venous anomaly, can be complicated by pathology. The objective of this review article is to provide a descriptive and pictorial review of common anatomic and physiologic variations in the venous drainage system of the brain, spine, and orbits that can mimic pathology. Neuroimaging findings of related pathologies and differences in clinical presentations will also be discussed to assist in the approach to differential diagnosis.
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Amyloid deposition, tau neurofibrillary tangles, and cerebrovascular dysfunction are important pathophysiologic features in Alzheimer's disease. Pittsburgh compound B ([11 C]-PIB) is a positron emission tomography (PET) radiotracer used to quantify amyloid deposition in vivo. In addition, certain models of [11 C]-PIB delivery reflect cerebral blood flow rather than amyloid plaques. As cerebral blood flow and perfusion deficits are associated with white matter pathology, we hypothesized that [11 C]-PIB delivery in white matter regions may reflect white matter integrity. ⋯ Future studies are warranted to explore whether [11 C]-PIB PET is a "triple biomarker" that may provide information about amyloid deposition, cerebral blood flow, and white matter pathology.
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The cingulate island sign (CIS) on 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET); ie, the relative preservation of mid-posterior cingulate cortex metabolism, is a supportive biomarker in the diagnostic criteria for dementia with Lewy bodies (DLB). However, limited information is currently available on the diagnostic value of the CIS on FDG-PET or 123 I-iodoamphetamine single-photon emission computed tomography (IMP-SPECT) for differentiating between mild cognitive impairment (MCI) due to Alzheimer's disease (AD) (MCI-AD) and MCI due to DLB (MCI-DLB). ⋯ The FDG-PET and IMP-SPECT derived CIS ratios are both useful for differentiating between AD and DLB. The FDG-PET derived CIS ratio is more valuable than the IMP-SPECT derived CIS ratio for differential diagnosis in patients with MCI. A larger study is needed to confirm these results.