Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Evidence of remote optic neuritis is often used to support a diagnosis of multiple sclerosis (MS). Optical coherence tomography (OCT) can provide qualitative and quantitative data on the retina, where the effects of optic neuritis can be seen. Our aim was to determine whether there is a quantitative difference in retinal structures in eyes with optic neuritis compared with those without, and which measures were best able to discriminate eyes with a history of optic neuritis from nonoptic neuritis eyes in MS patients. ⋯ Optic neuritis is associated with thinning in multiple regions of the retina. Optic neuritis eyes can be differentiated most accurately from nonoptic neuritis eyes using OCT. Our work suggests a potential role for OCT in documenting a remote history of optic neuritis to corroborate a diagnosis of MS.
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Apparent diffusion coefficient (ADC) values have been shown to assist in differentiating cerebellar pilocytic astrocytomas and medulloblastomas. Previous studies have applied only ADC measurements and calculated the mean/median values. Here we investigated the value of diffusion tensor imaging (DTI) histogram characteristics of the entire tumor for differentiation of cerebellar pilocytic astrocytomas and medulloblastomas. ⋯ The 25th percentile for MD yields the best results for the presurgical differentiation between pediatric cerebellar pilocytic astrocytomas and medulloblastomas. The analysis of other DTI metrics does not provide additional diagnostic value. Our study confirms the diagnostic value of the quantitative histogram analysis of DTI data in pediatric neuro-oncology.
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Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data. ⋯ Spatial smoothing of ASL images increased false positive results in the discrimination of hypoperfusion conditions from healthy elderly. It also decreased interreader agreement. However, regional characterization and subjective perception of image quality was improved.
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Pathologic diagnosis is the gold standard in evaluating imaging measures developed as biomarkers for pathologically defined disorders. A brain MRI atlas representing autopsy-sampled tissue can be used to directly compare imaging and pathology findings. Our objective was to develop a brain MRI atlas representing the cortical regions that are routinely sampled at autopsy for the diagnosis of Alzheimer's disease (AD). ⋯ In an atlas developed for imaging and pathologic correlation studies, we demonstrated that antemortem amyloid burden measured in the atlas ROIs on amyloid PET is strongly correlated with β-amyloid density measured on histology. This atlas can be used in imaging and pathologic correlation studies.
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Comparative Study
Comparison of Glioblastomas and Brain Metastases using Dynamic Contrast-Enhanced Perfusion MRI.
To compare glioblastoma and brain metastases using T1-weighted dynamic contrast-enhanced (DCE)-MRI perfusion technique. ⋯ DCE-MRI showed that it has a potential to differentiate glioblastomas, melanoma metastases and hypovascular brain tumors. Logarithmic slope of the washout phase and AUC of the signal intensity time curve were shown to be the best discriminator between hypervascular and hypovascular neoplasms.