Purpose
To determine the correlation in abdominal aortic stiffness obtained using magnetic resonance elastography (MRE) (μMRE) and MRI-based pulse wave velocity (PWV) shear stiffness (μPWV) estimates in normal volunteers of varying age; and also to determine the correlation between μMRE and μPWV.
Methods
In-vivo aortic MRE and MRI were performed on 21 healthy volunteers with ages ranging from 18 to 65 years to obtain wave and velocity data along the long-axis of the abdominal aorta. The MRE wave images were analyzed to obtain mean stiffness, and the phase contrast images were analyzed to obtain PWV measurements and indirectly estimate stiffness values from Moens-Korteweg equation.
Results
Both μMRE and μPWV measurements increased with age, demonstrating linear correlations with R2 values of 0.81 and 0.67, respectively. Significant difference (p≤0.001) in mean μMRE and μPWV between young and old healthy volunteers was also observed. Furthermore, a poor linear correlation of R2 value of 0.43 was determined between μMRE and μPWV in initial pool of volunteers.
Conclusion
The results of this study indicate linear correlations between μMRE and μPWV with normal aging of the abdominal aorta. Significant differences in mean μMRE and μPWV between young and old healthy volunteers were observed.
Summary
In considering the challenges of approaches to clinical imaging, we are faced with choices that sometimes are impacted by rather dogmatic notions about what is a better or worse technology to achieve the most useful diagnostic image for the patient. For example, is PET or SPECT most useful in imaging any particular disease dissemination? The dictatorial approach would be to choose PET, all other matters being equal. But is such a totalitarian attitude toward imaging selection still valid? In the face of new receptor targeted SPECT agents one must consider the remarkable specificity and sensitivity of these agents. 99mTc-Tilmanocept is one of the newest of these agents, now approved for guiding sentinel node biopsy (SLNB) in several solid tumors. Tilmanocept has a Kd of 3×10−11 M, and it specificity for the CD206 receptor is unlike any other agent to date. This coupled with a number of facts, that specific disease-associated macrophages express this receptor (100 to 150 thousand receptors), the receptor has multiple binding sites for tilmanocept (>2 sites per receptor) and that these receptors are recycled every 15 minutes to bind more tilmanocept (acting as intracellular “drug compilers” of tilmanocept into non-degraded vesicles), give serious pause as to how we select our approaches to diagnostic imaging. Clinically, the size of SLNs varies greatly, some, anatomically, below the machine resolution of SPECT. Yet, with tilmanocept targeting, the SLNs are highly visible with macrophages stably accruing adequate 99mTc-tilmanocept counting statistics, as high target-to-background ratios can compensate for spatial resolution blurring. Importantly, it may be targeted imaging agents per se, again such as tilmanocept, which may significantly shrink any perceived chasm between the imaging technologies and anchor the diagnostic considerations in the targeting and specificity of the agent rather than any lingering dogma about the hardware as the basis for imaging approaches. Beyond the elements of imaging applications of these agents is their evolution to therapeutic agents as well, and even in the neo-logical realm of theranostics. Characteristics of agents such as tilmanocept that exploit the natural history of diseases with remarkably high specificity are the expectations for the future of patient- and disease-centered diagnosis and therapy.
Introduction: Obesity, DM, HTN and metabolic syndrome (MtS) are associated with nonalcoholic fatty liver disease (NAFLD). NAFLD is characterized into, nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH), which are increasingly prevalent chronic liver diseases in the US. Data shows that there is a high incidence of MtS in African American (AA) individuals, however the AA population is known to have a lower incidence of NAFLD as compared to Caucasian and Hispanic Americans. Given the high number of AA patients in our clinic and paucity of data on the reason for the low incidence of NAFLD in the AA population, we assessed risk factors and non-invasive serum markers for fibrosis between AA and nonAA patients at their earliest clinic visits to ascertain potential underlying causes. Methods: Using the ICD-10 codes for NAFLD (K76.0) and NASH (K75.81), we identified patients between 2017 and 2020 with sufficient data to confirm accurate diagnosis. We defined NAFL patients as those with significant steatosis (by ultrasound) and minimal fibrosis and NASH patients as those with significant steatosis and advanced fibrosis (F2-F4). Statistical analysis was performed using JMP-SAS software. Results: We identified 216 patients with NAFLD (NAFL5133, NASH583). Despite the predominance ( .80%) of AA patients in our clinic, AA patients constituted only 54% of the NAFLD patients (AA5116, Asian518, Caucasian548, Hispanic517, Middle Eastern516). Of the total AA patients with NAFLD, 34% had NASH which was not statistically significant in proportion when compared to the nonAA NASH patients. When differences between AA and nonAA NAFL patients were evaluated, age at diagnosis (AA older), APRI and FIB-4 (AA lower) were significantly different. APRI and FIB-4 scores were lower in AA NASH than nonAA NASH patients but the difference was not significant. Common risk factors for NAFLD (HTN, DM, obesity, and MtS) were not significant when compared in proportion of population between AA and nonAA patients (Table ). Conclusion: Our percentage of NAFLD AA patients did not reflect the percentage of the broader clinic population suggesting a potential protective effect of ethnicity with relation to NAFLD. Most of the risk factors were more pronounced in NASH as compared to NAFL, but there were no major racial differences in risk factors that could account for the known lower incidence of NAFLD in AA versus nonAA patients. Further study over a longer time period is necessary to elucidate the underlying causality.
Introduction: There is a rise in colorectal cancer (CRC) in younger patients less than 45 years of age. However, there is limited data on the prevalence of colorectal neoplasia in patients younger than 45 years. Our study's objective was to evaluate the adenoma positivity rate (APR) for patients 40-49 years undergoing colonoscopy regardless of indication Methods: We retrospectively reviewed our endoscopy database for all patients ages 40-49 who underwent colonoscopy at our institution between January 2018 and December 2021. We analyzed patients' demographics, BMI, indication, findings, and bowel preparation. Colonoscopies were excluded if the bowel preparation was inadequate (n548), or the pathology revealed colonic adenocarcinoma (n52). Statistical analysis was performed utilizing Chi-square testing with significance set at a P , 0.05
Figure 1. a-Spiration Valve in place (endoscopic image) b-TEF before treatment (fluoroscopic image) c-Spiration valve in situ controlling the leak (fluoroscopic image).
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