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OBJECTIVE - To estimate effective dose of kidney-ureter-bladder (KUB) radiographs in a contemporary population of patients with urolithiasis.
METHODS - A retrospective review was performed to identify patients visiting a urology clinic for urolithiasis where a KUB was obtained and whom had a recent computed tomography (CT). Effective dose for KUBs was estimated using a Monte Carlo based simulation program and for CT utilizing the reported dose-length-product. Age, gender, body mass index, and abdominal diameter were analyzed for association with effective dose. KUBs performed at outside facilities in referred patient were compared to those obtained locally when available.
RESULTS - Fifty-four patients were identified meeting criteria. The majority (92.6%) of KUBs contained multiple radiographs. Mean effective dose was 2.15 mSv ± 1.67 mSv. Only 26% of examinations effective dose was under 1 mSv. Body mass index, abdominal thickness, and image count were all associated with an increase in dose (P < .01 each). Similar to local KUBs, 88% of outside examinations contained multiple images.
CONCLUSION - KUB examinations in this contemporary setting are associated with a 2-fold higher effective dose then is often referenced. Increased effective dose is associated with increased patient size and number of images acquired. Nearly 1 in 5 patient's KUB effective dose was similar to a low-dose CT. KUBs role should be re-examined given its limited sensitivity, specificity, associated radiation, and other available imaging options.
Copyright © 2018. Published by Elsevier Inc.
BACKGROUND - Determine the prognostic impact of magnetic resonance imaging (MRI)-defined diffuse axonal injury (DAI) after traumatic brain injury (TBI) on functional outcomes, quality of life, and 3-year mortality.
METHODS - This retrospective single center cohort included adult trauma patients (age > 17 years) admitted from 2006 to 2012 with TBI. Inclusion criteria were positive head computed tomography with brain MRI within 2 weeks of admission. Exclusion criteria included penetrating TBI or prior neurologic condition. Separate ordinal logistic models assessed DAI's prognostic value for the following scores: (1) hospital-discharge Functional Independence Measure, (2) long-term Glasgow Outcome Scale-Extended, and (3) long-term Quality of Life after Brain Injury-Overall Scale. Cox proportional hazards modeling assessed DAI's prognostic value for 3-year survival. Covariates included age, sex, race, insurance status, Injury Severity Score, admission Glasgow Coma Scale Score, Marshall Head computed tomography Class, clinical DAI on MRI (Y/N), research-level anatomic DAI Grades I-III (I, cortical; II, corpus callosum; III, brainstem), ventilator days, time to follow commands, and time to long-term follow-up (for logistic models).
RESULTS - Eligibility criteria was met by 311 patients, who had a median age of 40 years (interquartile range [IQR], 23-57 years), Injury Severity Score of 29 (IQR, 22-38), intensive care unit stay of 6 days (IQR, 2-11 days), and follow-up of 5 years (IQR, 3-6 years). Clinical DAI was present on 47% of MRIs. Among 300 readable MRIs, 56% of MRIs had anatomic DAI (25% Grade I, 18% Grade II, 13% Grade III). On regression, only clinical (not anatomic) DAI was predictive of a lower Functional Independence Measure score (odds ratio, 2.5; 95% confidence interval, 1.28-4.76], p = 0.007). Neither clinical nor anatomic DAI were related to survival, Glasgow Outcome Scale-Extended, or Quality of Life after Brain Injury-Overall Scale scores.
CONCLUSION - In this longitudinal cohort, clinical evidence of DAI on MRI may only be useful for predicting short-term in-hospital functional outcome. Given no association of DAI and long-term TBI outcomes, providers should be cautious in attributing DAI to future neurologic function, quality of life, and/or survival.
LEVEL OF EVIDENCE - Epidemiological, level III; Therapeutic, level IV.
Limited information exists on the anatomically-specific early stage events leading to clinically detectable mineral aggregates in the renal papilla. In this study, quantitative multiscale correlative maps of structural, elemental and biochemical properties of whole medullo-papillary complexes from human kidneys were developed. Correlative maps of properties specific to the uriniferous and vascular tubules using high-resolution X-ray computed tomography, scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy, and immunolocalization of noncollagenous proteins (NCPs) along with their association with anatomy specific biominerals were obtained. Results illustrated that intratubular spherical aggregates primarily form at the proximal regions distant from the papillary tip while interstitial spherical and fibrillar aggregates are distally located near the papillary tip. Biominerals at the papillary tip were closely localized with 10 to 50 μm diameter vasa recta immunolocalized for CD31 inside the medullo-papillary complex. Abundant NCPs known to regulate bone mineralization were localized within nanoparticles, forming early pathologic mineralized regions of the complex. Based on the physical association between vascular and urothelial tubules, results from light and electron microscopy techniques suggested that these NCPs could be delivered from vasculature to prompt calcification of the interstitial regions or they might be synthesized from local vascular smooth muscle cells after transdifferentiation into osteoblast-like phenotypes. In addition, results provided insights into the plausible temporal events that link the anatomically specific intratubular mineral aggregates with the interstitial biomineralization processes within the functional unit of the kidney.
OBJECTIVE - To compare the measured stone burden recorded between urologists and radiologists, and examine how these differences could potentially impact stone management. As current urologic stone surgery guideline recommendations are based on stone size, accurate stone measurements are crucial to direct appropriate treatment. This study investigated the discrepant interpretation that often exists between urologic surgeons and radiologists' estimation of patient urinary stone burden.
MATERIALS AND METHODS - From November 2015 through August 2016, new patients prospectively enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU) were included if they had computed tomography images available and an accompanying official radiologic report at the time of their urologist provider visit. Stone number and aggregate stone size were compared between the urologic interpretation and the corresponding radiologic reports.
RESULTS - Of 219 patients who met the inclusion criteria, concordance between urologic and radiologic assessment of aggregate stone size was higher for single stone sizing (63%) compared with multiple stones (32%). Statistical significance was found in comparing the mean difference in aggregate stone size for single and multiple stones (P <.01). Over 33% of stone-containing renal units had a radiologic report with an unclear size estimation or size discrepancy that could lead to non-guideline-driven surgical management.
CONCLUSION - Significant variation exists between urologic and radiologic computed tomography interpretations of stone burden. Urologists should personally review patient imaging when considering stone surgical management. A standardized method for measuring and reporting stone parameters is needed among urologists and radiologists.
Copyright © 2017 Elsevier Inc. All rights reserved.
Background - Adiposity depots may differentially affect cognition. African Americans (AA) have higher rates of obesity and dementia but lower visceral adipose tissue (VAT) than whites, yet are underrepresented in studies of adiposity and cognition. Our study compared relations of cognitive function to clinical adiposity measures and computed tomography (CT)-imaged abdominal adiposity in AA.
Methods - CT-imaged subcutaneous adipose tissue (SAT) and VAT measurements were obtained in the AA cohort of the Genetic Epidemiology Network of Arteriopathy Study (N = 652, mean age 68 ± 8.4 years, 74% females, 59% obese, 82% hypertensive). Clinical adiposity measures included waist circumference (WC) and body mass index (BMI). Global cognition was operationalized as a global cognitive z-score generated from the average of four cognitive domain z-scores. Generalized estimating equations were used to examine cross-sectional associations between individual standardized adiposity measures and cognition, accounting for age, sex, education, smoking status, and familial clustering. A collective model was constructed including multiple supported adiposity measures and age-by-adiposity interactions.
Results - In the collective model, higher WC was associated with worse global cognition, β = -0.12 (95%CI: -0.21, -0.03); higher SAT was associated with better cognition, β = 0.09 (0.01, 0.18); higher BMI was associated with worse cognition at younger ages with attenuation at older ages (BMI-by-age-interaction p = .004). VAT was not significantly associated with global cognition, β = -0.03 (-0.07, 0.02).
Conclusions - WC may be the simplest and most efficient measure of adiposity to assess with respect to cognition in clinical settings, although studies to determine mechanistic effects of subcutaneous and other adiposity depots on cognition are warranted.
PURPOSE - The identification and targeting of biomarkers specific to prostate cancer (PCa) could improve its detection. Given the high expression of translocator protein (TSPO) in PCa, we investigated the use of [F]VUIIS1008 (a novel TSPO-targeting radioligand) coupled with positron emission tomography (PET) to identify PCa in mice and to characterize their TSPO uptake.
PROCEDURES - Pten, Trp53 prostate cancer-bearing mice (n = 9, 4-6 months old) were imaged in a 7T MRI scanner for lesion localization. Within 24 h, the mice were imaged using a microPET scanner for 60 min in dynamic mode following a retro-orbital injection of ~ 18 MBq [F]VUIIS1008. Following imaging, tumors were harvested and stained with a TSPO antibody. Regions of interest (ROIs) were drawn around the tumor and muscle (hind limb) in the PET images. Time-activity curves (TACs) were recorded over the duration of the scan for each ROI. The mean activity concentrations between 40 and 60 min post radiotracer administration between tumor and muscle were compared.
RESULTS - Tumor presence was confirmed by visual inspection of the MR images. The uptake of [F]VUIIS1008 in the tumors was significantly higher (p < 0.05) than that in the muscle, where the percent injected dose per unit volume for tumor was 7.1 ± 1.6 % ID/ml and that of muscle was < 1 % ID/ml. In addition, positive TSPO expression was observed in tumor tissue analysis.
CONCLUSIONS - The foregoing preliminary data suggest that TSPO may be a useful biomarker of PCa. Therefore, using TSPO-targeting PET ligands, such as [F]VUIIS1008, may improve PCa detectability and characterization.
BACKGROUND - The clinical significance of pneumonia visualized on CT scan in the setting of a normal chest radiograph is uncertain.
METHODS - In a multicenter prospective surveillance study of adults hospitalized with community-acquired pneumonia (CAP), we compared the presenting clinical features, pathogens present, and outcomes of patients with pneumonia visualized on a CT scan but not on a concurrent chest radiograph (CT-only pneumonia) and those with pneumonia visualized on a chest radiograph. All patients underwent chest radiography; the decision to obtain CT imaging was determined by the treating clinicians. Chest radiographs and CT images were interpreted by study-dedicated thoracic radiologists blinded to the clinical data.
RESULTS - The study population included 2,251 adults with CAP; 2,185 patients (97%) had pneumonia visualized on chest radiography, whereas 66 patients (3%) had pneumonia visualized on CT scan but not on concurrent chest radiography. Overall, these patients with CT-only pneumonia had a clinical profile similar to those with pneumonia visualized on chest radiography, including comorbidities, vital signs, hospital length of stay, prevalence of viral (30% vs 26%) and bacterial (12% vs 14%) pathogens, ICU admission (23% vs 21%), use of mechanical ventilation (6% vs 5%), septic shock (5% vs 4%), and inhospital mortality (0 vs 2%).
CONCLUSIONS - Adults hospitalized with CAP who had radiological evidence of pneumonia on CT scan but not on concurrent chest radiograph had pathogens, disease severity, and outcomes similar to patients who had signs of pneumonia on chest radiography. These findings support using the same management principles for patients with CT-only pneumonia and those with pneumonia seen on chest radiography.
Copyright © 2017 American College of Chest Physicians. All rights reserved.