Multimodality oncologic evaluation of superficial neck and facial lymph nodes.

Involvement of lymph nodes in patients with head and neck cancers impacts treatment and prognosis. Head and neck lymph nodes are comprised of superficial and deep groups which are interconnected. The deep lymph nodes, predominantly centered along internal jugular veins, are very well-known to radiologists and clinicians. However, superficial lymph nodes that drain lymph from the scalp, face, and neck are much less recognized. Here, we describe the anatomic and imaging features of these superficial lymph nodes on CT, MRI, and PET in oncologic settings.

Regional brain amyloid-ß accumulation associates with domain-specific cognitive performance in Parkinson disease without dementia.

Parkinson disease patients develop clinically significant cognitive impairment at variable times over their disease course, which is often preceded by milder deficits in memory, visuo-spatial, and executive domains. The significance of amyloid-ß accumulation to these problems is unclear. We hypothesized that amyloid-ß PET imaging by 18F-florbetapir, a radiotracer that detects fibrillar amyloid-ß plaque deposits, would identify subjects with global cognitive impairment or poor performance in individual cognitive domains in non-demented Parkinson disease patients. We assessed 61 non-demented Parkinson disease patients with detailed cognitive assessments and 18F-florbetapir PET brain imaging. Scans were interpreted qualitatively (positive or negative) by two independent nuclear medicine physicians blinded to clinical data, and quantitatively by a novel volume-weighted method. The presence of mild cognitive impairment was determined through an expert consensus process using Level 1 criteria from the Movement Disorder Society. Nineteen participants (31.2%) were diagnosed with mild cognitive impairment and the remainder had normal cognition. Qualitative 18F-florbetapir PET imaging was positive in 15 participants (24.6%). Increasing age and presence of an APOE ε4 allele were associated with higher composite 18F-florbetapir binding. In multivariable models, an abnormal 18F-florbetapir scan by expert rating was not associated with a diagnosis of mild cognitive impairment. However, 18F-florbetapir retention values in the posterior cingulate gyrus inversely correlated with verbal memory performance. Retention values in the frontal cortex, precuneus, and anterior cingulate gyrus retention values inversely correlated with naming performance. Regional cortical amyloid-ß amyloid, as measured by 18F-florbetapir PET, may be a biomarker of specific cognitive deficits in non-demented Parkinson disease patients.

Relative 11C-PiB Delivery as a Proxy of Relative CBF: Quantitative Evaluation Using Single-Session 15O-Water and 11C-PiB PET.

UNLABELLED: The primary goal of this study was to assess the suitability of (11)C-Pittsburgh compound B ((11)C-PiB) blood-brain barrier delivery (K1) and relative delivery (R1) parameters as surrogate indices of cerebral blood flow (CBF), with a secondary goal of directly examining the extent to which simplified uptake measures of (11)C-PiB retention (amyloid-ß load) may be influenced by CBF, in a cohort of controls and patients with mild cognitive impairment (MCI) and Alzheimer disease (AD). METHODS: Nineteen participants (6 controls, 5 AD, 8 MCI) underwent MR imaging, (15)O-water PET, and (11)C-PiB PET in a single session. Fourteen regions of interest (including cerebellar reference region) were defined on MR imaging and applied to dynamic coregistered PET to generate time-activity curves. Multiple analysis approaches provided regional (15)O-water and (11)C-PiB measures of delivery and (11)C-PiB retention that included compartmental modeling distribution volume ratio (DVR), arterial- and reference-based Logan DVR, simplified reference tissue modeling 2 (SRTM2) DVR, and standardized uptake value ratios. Spearman correlation was performed among delivery measures (i.e., (15)O-water K1 and (11)C-PiB K1, relative K1 normalized to cerebellum [Rel-K1-Water and Rel-K1-PiB], and (11)C-PiB SRTM2-R1) and between delivery measures and (11)C-PiB retention, using the Bonferroni method for multiple-comparison correction. RESULTS: Primary analysis showed positive correlations (ρ ≈0.2-0.5) between (15)O-water K1 and (11)C-PiB K1 that did not survive Bonferroni adjustment. Significant positive correlations were found between Rel-K1-Water and Rel-K1-PiB and between Rel-K1-Water and (11)C-PiB SRTM2-R1 (ρ ≈0.5-0.8, P < 0.0036) across primary cortical regions. Secondary analysis showed few significant correlations between (11)C-PiB retention and relative (11)C-PiB delivery measures (but not (15)O-water delivery measures) in primary cortical areas that arose only after accounting for cerebrospinal fluid dilution. CONCLUSION: (11)C-PiB SRTM2-R1 is highly correlated with regional relative CBF, as measured by (15)O-water K1 normalized to cerebellum, and cross-sectional (11)C-PiB retention did not strongly depend on CBF across primary cortical regions. These results provide further support for potential dual-imaging assessments of regional brain status (i.e., amyloid-ß load and relative CBF) through dynamic (11)C-PiB imaging.

A semi-quantitative method for correlating brain disease groups with normal controls using SPECT: Alzheimer's disease versus vascular dementia.

PURPOSE: To demonstrate the utility of semi-quantitative circumferential-profile analysis of regional cerebral blood flow (rCBF) SPECT in Alzheimer's disease (AD) versus white matter vascular dementia (WM-VaD). METHODS: Subjects underwent dementia evaluation, MRI and Tc-99m HMPAO SPECT. rCBF patterns from 11 AD and 20 WM-VaD patients were compared to 17 controls using semi-quantitative circumferential-profile analysis. RESULTS: AD patients showed more significant semi-quantitative circumferential-profile reductions in the posterior temporo-parietal regions, whereas WM-VaD patients demonstrated greater reductions involving the frontal regions of the brain. CONCLUSION: Semi-quantitative circumferential-profile analysis provides a practical semi-quantitative method to evaluate brain SPECT scans in AD versus WM-VaD patients.