Acre Test Research Articles

Can remote testing for chronic kidney disease improve outcomes without widening existing health inequalities? A collaborative quality improvement project in primary care.

In the UK, chronic kidney disease (CKD) is a prevalent, silent and strong predictor of cardiovascular disease. Identification of CKD is poor in primary care, particularly in minority ethnic and socio-economically deprived groups. To investigate feasibility of remote ACR testing to improve the detection and management of CKD in underserved groups. 13 591 tests were sent out across South East London. Individuals with diabetes and no ACR in the past year were offered a remote ACR test to complete at home with a smartphone using a validated app (Healthy.io). We extracted data on demographics, medical comorbidities and medication. Analyses (Stata) describe who completed the test. Twenty-seven practices agreed to participate. Analyses of 6082 tests sent show the test completion rate was 46.8%. Adjusted odds ratios demonstrated that people were less likely to complete testing if over 70 years (OR 0.71, 95% CI 0.57 to 0.89) and over 80 (OR 0.43, CI 95% 0.33 to 0.56) compared to <40 years old; people from CORE20 groups (most deprived quintile) were also less likely to complete testing (OR 0.68, 95% CI 0.61 to 0.76) and those with missing data and those with no recorded healthcare interactions within the last 5 years were also less likely to complete testing. Remote ACR testing presents an opportunity to diagnose early CKD but there is still inequity in who completes testing. Engagement with stakeholders is needed to explore innovative ways to implement remote ACR testing to achieve equitable CKD screening.

#4519 CAN WE REPLACE URINE TESTING AND DELIVER A STEP CHANGE IN ACCESS TO RENOPROTECTIVE MEDICATIONS?

Abstract Background and Aims Albuminuria is a medical condition characterized by leakage of albumin into the urine due to kidney damage. The condition is diagnosed by heightened Albumin to Creatinine ratio in the urine (ACR) and is typically categorized into microalbuminuria (ACR ≥ 30, &amp;lt; 300 mg/g mg/g) and macroalbuminuria (ACR ≥ 300 mg/g). Currently, despite compelling data, only a minority of patients with diabetes, and rarely individuals without diabetes, are screened for albuminuria in a systematic way. ACR tests also present high intra-person variability, making it harder to identify meaningful biologic changes and increasing complexity of clinical trials. In this study we develop a method using machine learning to predict ACR level from Electronic Health Records, excluding urine tests, and validated the model for identifying patients with albuminuria. Identifying patients with undiagnosed albuminuria could help slow progression of kidney disease and be used to speed up recruitment to, and reduce screen failures in, clinical trials. Method We developed a Quantile Regression model for ACR using US Limited IBM MarketScan Explorys Claims-EMR Data Set (LCED). We included subjects who had an ACR test (0 &amp;lt; ACR ≤ 5000 mg/g) and was of at least 18 years of age. Patient demographics (age, sex), vital signs (BMI, Blood Pressure) and 8 common blood tests (Albumin, Bilirubin, Creatinine, HbA1C, Triglyceride, Glucose, White Blood Cell count &amp; ALT) were used as covariates. A tree based gradient boosting framework (LightGBM) was used to train the quantile regression models, viz., the 25-, 50-, and 75-percentiles of ACR conditioned on the covariates. The model was then validated on all qualified subjects in Optum's de-identified Clinformatics® Data Mart Database (2007-2021). We evaluated performance using the metrics Area Under the Curve (AUC), precision (PPV), specificity (TNR), and sensitivity (TPR). Finally, we use Kaplan-Meier estimates to compare the risk of progression to kidney failure as identified by ICD codes (Chronic kidney disease, stage 5; End stage renal disease; Dependence on renal dialysis; Unspecified kidney failure; Kidney transplant) of both the predicted and measured ACR values. Results A final cohort of 63,459 individuals matched the inclusion and exclusion criteria in LCED and 5,857,385 individuals in Optum. Using the 25% quantile to predict patients at risk, the model consistently reaches a PPV greater than 0.8 and a specificity (TNR) greater than 0.99 (Table 1). The risk of progression to kidney failure increases with both increased predicted and measured ACR (Figure 1). Conclusion The results show that the models have discriminative power in all datasets. It predicts both micro- and macro-albuminuria with a PPV above 80% for the 25-quartile. However, classification performance is lacking in sensitivity, i.e., subjects suffering from albuminuria may not be classified as such. By using the median prediction of ACR we identify patient subpopulations that have a risk of kidney failure at least on par with the true ACR subpopulation targeted. This means that the method can be used confidently to identify at-risk individuals. Therefore, our model is advantageous in applications such as identifying undiagnosed albuminuria and pre-screening for clinical trials, where high PPV is more important than sensitivity. We intend to validate the model further for outcomes prediction in an upcoming CKD trial.

SU‐F‐J‐159: Influence of the Elevated Posterior Position by Using the Customized Vacuum‐Bag On the Abdominal MR Image Quality: A Quantitative Phantom Study

Purpose:Signal‐to‐noise ratio(SNR) of MR abdominal imaging in diagnostic radiology is maximized by minimizing the coil‐to‐patient distance. However, for radiotherapy applications, customized vacuum‐bag is needed for abdominal immobilization at the cost of the increasing distance to the posterior spine coil. This sub‐optimized coil setting for RT applications may compromise image quality, such as SNR and homogeneity, thus potentially affect tissue delineation. In this study, we quantitatively evaluate the effect of the vertical position change on SNR and image quality change using an ACR MR phantom.Methods:An ACR MR phantom was placed on the flat couch top. Images were acquired using an 18‐channel body array coil and spine coil on a dedicated 1.5T MR‐simulator. The scan was repeated three times with the ACR phantom elevated up to 7.5cm from the couch top, with a step size of 2.5cm. All images were acquired using standard ACR test sequence protocol of 2D spin‐echo T1‐weighted(TR/TE=500/200ms) and T2‐weighted(TR/TE1/TE2=2000/20/80) sequences. For all scans, pre‐scan normalization was turned on, and the distance between the phantom and the anterior 18‐channel body array coil was kept constant. SNR was calculated using the slice with a large water‐only region of the phantom. Percent intensity uniformity(PIU) and low contrast object detectability(LCD) were assessed by following ACR test guidelines.Results:The decrease in image SNR(from 335.8 to 169.3) and LCD(T1: from 31 to 19 spokes, T2: 26 to 16 spokes) were observed with increasing vertical distance. After elevating the phantom by 2.5cm(approximately the thickness of standard vacuum‐bag), SNR change(from 335.8 to 275.5) and LCD(T1: 31 to 26 spokes, T2: 26 to 21 spokes) change were noted. However, similar PIU was obtained for all choices of vertical distance (T1: 94.5%–95.0%, T2: 94.4%–96.8%).Conclusion:After elevating the scan object, reduction in SNR level and contrast detectability but no change in image homogeneity was observed.

Technical Note: Compact three-tesla magnetic resonance imager with high-performance gradients passes ACR image quality and acoustic noise tests.

A compact, three-tesla magnetic resonance imaging (MRI) system has been developed. It features a 37 cm patient aperture, allowing the use of commercial receiver coils. Its design allows simultaneously for gradient amplitudes of 85 millitesla per meter (mT/m) sustained and 700 tesla per meter per second (T/m/s) slew rates. The size of the gradient system allows for these simultaneous performance targets to be achieved with little or no peripheral nerve stimulation, but also raises a concern about the geometric distortion as much of the imaging will be done near the system's maximum 26 cm field-of-view. Additionally, the fast switching capability raises acoustic noise concerns. This work evaluates the system for both the American College of Radiology's (ACR) MRI image quality protocol and the Food and Drug Administration's (FDA) nonsignificant risk (NSR) acoustic noise limits for MR. Passing these two tests is critical for clinical acceptance. In this work, the gradient system was operated at the maximum amplitude and slew rate of 80 mT/m and 500 T/m/s, respectively. The geometric distortion correction was accomplished by iteratively determining up to the tenth order spherical harmonic coefficients using a fiducial phantom and position-tracking software, with seventh order correction utilized in the ACR test. Acoustic noise was measured with several standard clinical pulse sequences. The system passes all the ACR image quality tests. The acoustic noise as measured when the gradient coil was inserted into a whole-body MRI system conforms to the FDA NSR limits. The compact system simultaneously allows for high gradient amplitude and high slew rate. Geometric distortion concerns have been mitigated by extending the spherical harmonic correction to higher orders. Acoustic noise is within the FDA limits.

SU‐E‐J‐211: Assessing the Consistency of the ViewRay 0.35 T MRI System

Purpose:ViewRay is a novel image‐guided radiotherapy approach with an integrated 0.35 T MR unit and three Cobalt‐60 heads. In order to continuously ensure the high resolution and high soft tissue contrast available in MR images, we quantified a multitude of relevant imaging parameters over a period of six months to establish its stability and imaging quality. In the assessment process, consideration is also given to the need to establish the number of tests required to have confidence in the performance of the system for radiation therapy planning applications.Methods:Daily, weekly, monthly and annual imaging tests were performed over a period of six months using standardized phantoms (a 24 cm diameter sphere and the ACR phantom) to quantify the performance of the system. In addition to the ACR and NEMA recommended tests, we also included element testing, spatial integrity, Eddy current and magnetic field inhomogeneity measurements. The ACR test is used for assessing the following parameters for T1 and T2: geometric accuracy, high contrast spatial resolution, slice thickness accuracy, slice position accuracy, percent signal ghosting, low contrast object detectability. It also includes percent image uniformity (PIU) for T1. The NEMA test is primarily designed to check SNR and PIU.Results:Over the period of six months, all the parameters were maintained within the recommendations provided in the ACR and NEMA standards. PIU and SNR were found to be sensitive to malfunctions in the components of the multileaf collimators. Details of the findings will be presented.Conclusion:The data suggests that ViewRay imaging system has functioned in a consistent and reliable manner. MR imaging from ViewRay 0.35T system complies with the ACR and NEMA recommended acceptance standards.

SU‐E‐I‐47: Simultaneous Acquisition Quality Assurance and Design of Fused MRIMRS Phantom for the Performance Evaluation

Purpose:The objectives of this study were to develop MRI‐MRS fused phantom with metabolite inserts for QA, to optimize simultaneously QA parameters using fused phantom and to conduct quantitative analysis of sixteen metabolites solution with layered shape vials using localization sequence.Methods:The circular cylinder body was filled with waterdiluted CuSO4(0.7g/L) for having a T1 time shorting function and NaCl(75mM) to make similarly with bodily salt. The solutions of the 10 metabolites were prepared at about 100mM and pH of the solution was adjusted using K2HPO4(72mM) and KH2PO4(28mM) in H2O at pH 7.0. All measurements of MRI, MRS were made using a 3.0 T scanner (Achiva Tx 3.0 T) with SENSE – 32 channel head coil. The water signal of each volume of interest (VOI) was suppressed by variable pulse powers and optimized relaxation delays (VAPOR) applied before progress of the scan. The MRS scan parameters were as follows: point‐resolved spectroscopy (PRESS) sequence; TR, 2000 ms; TE, 35 ms; shim, iterative VOI; NSA, 64. In addition, this study was conducted with jMRUI‐5.0 software, with AMARES for spectral fitting.Results:Results of measured magnetic resonance imaging (MRI) factors were as follows: geometric accuracy (191.23±0.60), low contrast object detectability (28.13±0.835), image‐shift distortion (0.41±0.0032). Results of measured magnetic resonance spectroscopy (MRS) factors were as follows: signal‐to‐noise ratio (SNR) of the NAA (25.95±0.35), water suppression percent (99.70±0.09 %), line width of water peak (5.75±0.91 Hz).Conclusion:This study was to perform QA on SVS technique using the ACR‐MRS phantom which was refered ACR test guideline. The present study is being measured the quantitative accuracy of the metabolite and the accuracy of the position of the VOI which could be performed by layered shape vials. When QA protocol factors is established in this experiment, it is possible as MVS QA guideline.

The development of radioactive sample surrogates for training and exercises

Source term information is required for to reconstruct a device used in a dispersed radiological dispersal device. Simulating a radioactive environment to train and exercise sampling and sample characterization methods with suitable sample materials is a continued challenge. The Idaho National Laboratory has developed and permitted a radioactive response training range (RRTR), an 800 acre test range that is approved for open air dispersal of activated KBr, for training first responders in the entry and exit from radioactively contaminated areas, and testing protocols for environmental sampling and field characterization. Members from the Department of Defense, Law Enforcement, and the Department of Energy participated in the first contamination exercise that was conducted at the RRTR in the July 2011. The range was contaminated using a short lived radioactive 82Br isotope (activated KBr). Soil samples contaminated with KBr (dispersed as a solution) and glass particles containing activated potassium bromide that emulated dispersed radioactive materials (such as ceramic-based sealed source materials) were collected to assess environmental sampling and characterization techniques. This presentation summarizes the performance of a radioactive materials surrogate for use as a training aide for nuclear forensics.

Irbesartan in type 2 diabetic nephropathy treatment of microalbuminuria

Objective To observe irbesartan combined conventional therapy in treating type 2 diabetic patients with microalbuminuria results. Methods 80 cases in hospital with type 2 diabetic patients with microalbuminuria were randomly divided into two groups, in the conventional hypoglycemic, anticoagulant, lipidlowering, low-protein diet on the basis of the treatment, the treatment group:plus Heuberger losartan; control group: conventional treatment without irbesartan. All patients before treatment and at 3 months of treatment, at 6months for blood glucose determination of flight(FBG), postprandial blood glucose(PBG), endogenous creatinine clearance rate(Ccr), blood urea nitrogen(BUN), 24 h Upro, UAER, ACR test, then the two groups before and after treatment were analyzed. Results The treatment group of type 2 diabetic nephropathy in patients with microalbuminuria, in the conventional hypoglycemic, anticoagulant, lipid-lowering, low-protein diet based treatment, on the plus irbesartan, treatment for 3 nonths, 6 months after the 24 h Upro, UAER, ACR significantly better than the control group. Conclusion Irbesartan treatment of type 2 diabetic microalbuminuria in clinical efficacy and reliable. Key words: Type 2 diabetic nephropathy; Microalbuminuria; Irbesartan

Florfenicol residue depletion in channel catfish, Ictalurus punctatus (Rafinesque)

Florfenicol is a broad-spectrum antibiotic currently used in salmon aquaculture and proposed for use in channel catfish. A residue depletion study was performed under commercial aquaculture conditions to determine a withdrawal period. Market weight catfish (∼ 2 lb) maintained in a 0.1 acre test pond at a 7000 fish/acre stocking density were dosed with commercially formulated florfenicol in feed for 12 days at an average rate of 9.3 mg/kg b.w./day over the last 10 days, or 93% of the proposed dose. Twenty fish each were collected 1, 2, 4, 7, 14, and 21 days post withdrawal of medicated feed and levels of the marker residue, florfenicol amine (FFA), in muscle tissue were determined via a validated HPLC-UV method. By 4 days average muscle FFA levels were below the proposed 1000 ppb tolerance for FFA and beyond this time point all individual fish were below this level.

ACHIEVING OPTIMUM POST MINE RECLAMATION RESULTS THROUGH COMPUTER AIDED DESIGN

Recent technological advances have made it possible to map and model disturbed mine areas to plan the most cost effective manner in which to reclaim post mine land. The process not only can reduce the cost to reclaim each acre, but also enhances regulatory compliance. Results from a 21 acre test at Texas Utilities Mining Company`s Martin Lake-Oak Hill Mine have shown a significant reduction in dozer hours per acre to complete reclamation. A larger, more conclusive project has been completed at TUMCO`s Monticello-Winfield North Mine. The new project includes approximately 350 acres of the C-Area final pit. Results of this project have resulted in substantial cost savings versus conventional reclamation planning methods.

Insecticide Efficacy on the Pine Needle Midge, 1984

Abstract Eleven Vi acre test plots were installed in a Christmas tree stand in section 8 of Inverness township in Cheboygan County, MI. Each plot contained approximately 100 Scots pine trees ranging from 4 to 8 feet tall. Midge damage from the previous growing season was prevalent in all test plots and distributed evenly across the field. Experimental treatments were applied with a Solo 423 back pack mistblower calibrated in 15 gal/a. Sprays were applied once at the time of initial adult emergence as indicated by emergence trap catch (21 Jun). Winds were slight at the time of spray (&amp;lt;5mph) and the ambient air temperature was approximately 22°C. Meta-Systox R, the current industry standard, was applied by the cooperating grower twice with the first treatment applied 2 days after all other experimental treatments. The second treatment of Meta-Systox R was applied 1 wk after the first at recommended label rates. At that time all stages of larvae were present and damage was just beginning to show up in the area. Approximately 2 wk later the spray block was surveyed for infested fasicles. On 75 randomly selected Scots pine trees the number of infested fasicles were estimated on the top whorl and leader (Test 1). Total midge impact was measured at the end of the growing season using a rating system devised to rank trees ordinally according to the severity of damage. The system is as follows: 0, no discernable midge damage; 1, slight damage contributing to degrade slightly; 2, damage moderate causing noticible degrade and 3, damage severe, tree may be unmarketable for 1-3 years. During late October, just prior to harvest, fifty systematically selected trees were rated from each treatment plot (Test 2). Damage ratings were analysed using a Kruskal-Wallis analysis of variance. Individual treatment comparisons were made with a Wilcoxon Rank Sum test. This non parametric approach is analogous to a standard ANOVA and t tests although more appropriate for ordinal ratings that do not usually meet the assumptions of an ANOVA. Individual comparisons were made between the standard, Meta-systox R and each treatment. Comparisons marked with a “s –” performed significantly worse than the standard. Treatments marked with a “s + ” performed significantly better. Those treatments marked with a “ns” do not show a significantly different damage rating than the industry standard, Meta-systox R.