High Scanning Research Articles

The utility of coronary artery calcium in non-gated high resolution CT thorax scans in predicting cardiac events as compared to the Framingham risk score: a retrospective study

Abstract Background There is existing evidence to suggest a correlation between coronary artery calcification (CAC) measured using ECG-triggered chest computed tomography and cardiovascular disease. Further evidence has emerged to suggest a correlation between CAC measured using non-gated CT scans and cardiovascular disease. Herein, we sought to ascertain the utility of incidental findings of CAC on non-triggered high resolution CT (HRCT) thorax used for patients undergoing lung cancer screening or follow-up for interstitial lung disease and Framingham risk score (FRS) in predicting cardiovascular events. Methods The Computerised Radiology Information Service (CRIS) database was manually searched to determine all HRCT scans performed in a single trust from 05/2015 to 05/2016. The reports issued by Radiologists and images of selected studies were reviewed. For patients with CAC, we calculated the calcium score for patients using the Agatston method. Clinical events were determined from the electronic medical record without knowledge of patients' CAC findings. For these patients, the Framingham Risk Score (FRS) was also calculated. The primary end point of the study was composite of all-cause mortality and cardiac events (non-fatal myocardial infarction, coronary revascularization, new atrial fibrillation or heart failure episode requiring hospitalization). Results We selected 300 scans from a total of approximately 2000 scans performed over this time. Data at follow up was available for 100% of the patients, with a median duration of follow up of 1.6 years. Moderate to severe CAC was found in 35% of people. Multivariable analysis showed good concordance between CAC and FRS in predicting composite clinical end point. The Odds Ratio for cardiac events in patients with moderate to severe CAC was 5.3 (p<0.01) and for composite clinical end point was 3.4 (p<0.01). This is similar to the OR predicted by the FRS: 4.8; p<0.01 and 3.1; p<0.01 respectively. Only 6.2% of patients with moderate to severe CAC were currently statin treated. Conclusion In this retrospective study of patients with respiratory disease attending for HRCT scanning, co-incidentally detected CAC predicts cardiac events, with good concordance with the FRS. The incidental finding of CAC on non-gated CT scanning should be reported with Agatston score calculation allowing consideration of intervention to mitigate cardiovascular risk and optimize. Further multi-centre prospective studies of this strategy, with a larger patient cohort should be conducted to clarify the utility of CAC as a prediction tool to modify cardiac risk. Funding Acknowledgement Type of funding source: None

Symmetry and Finite-Size Effects in Quasi-Optical Extraordinarily THz Transmitting Arrays of Tilted Slots

Extraordinarily transmitting arrays are promising candidates for quasi-optical (QO) components due to their high frequency selectivity and beam scanning capabilities owing to the leaky-wave mechanism involved. We show here how by breaking certain unit cell and lattice symmetries, one can achieve a rich family of transmission resonances associated with the leaky-wave dispersion along the surface of the array. By combining 2-D and 1-D periodic method of moments (MoM) calculations with QO terahertz (THz) time-domain measurements, we provide physical insights, numerical, and experimental demonstration of the different mechanisms involved in the resonances associated with the extraordinary transmission peaks and how these evolve with the number of slots. Thanks to the THz instrument used, we are also able to explore the time-dependent emission of the different frequency components involved.

3047 – THE ADULT HEMATOPOIETIC STEM CELL NICHE IN ZEBRAFISH DEFINED USING CORRELATIVE LIGHT AND ELECTRON MICROSCOPY

Hematopoietic stem and progenitor cells (HSPCs) that originate from the hemogenic endothelium in the dorsal aorta to finally home and engraft within the adult niche, the fetal bone marrow (BM), become surrounded by niche cells in a complex microenvironment. The ultrastructure of this niche is not well defined as current imaging technology does not allow direct visualization of the fetal BM niche. Zebrafish have a similar hematopoietic ontogeny to mammals, and because the embryos are transparent, intrinsic HSPC interactions with the niche can be directly visualized. To track HSPCs during colonization of the presumptive adult niche, the kidney marrow (KM), we used our previously validated HSPC-specific transgenic reporter lines. In 5 days post fertilization fixed larvae, we detected ∼100 HSPCs/larva. To precisely locate these rare HSPCs within the larger dense KM, we genetically tagged endogenous HSPCs to track them live using lightsheet microscopy, followed by high resolution serial block-face scanning electron microscopy (SBEM). Using this technique, we could visually track single mCherry+ HSPCs, then confirm their exact location in a SBEM dataset with high contrast APEX2 peroxidase label. We found HSPC clusters within vessel lumens, as well as single HSPC in a novel perivascular niche. In this perivascular site, a single HSPC was seen to simultaneously contact one mesenchymal stromal cell, multiple endothelial cells, a glial-like cell and other hematopoietic cells. The glial-like cells were dopamine beta hydroxylase positive (dbh+) cells and treatment with small molecules inhibitor of dopamine led to significantly reduced HSPC numbers within the niche. Our approach can be used to identify the ultrastructure of single rare cells within dense tissues by using multiple imaging modalities and can also lead to the identification of previously uncharacterized cell types.

Experimental Study of High Temperature Phase Equilibria in the Iron-Rich Part of the Fe-P and Fe-C-P Systems

During the solidification of steel, phosphorus strongly segregates in the interdendritic liquid phase. In the continuous casting process, even low levels of P may have a detrimental effect on the final product quality. However, phosphorus is partly added up to 0.10 wt pct to improve the mechanical properties of advanced steel grades nowadays, e.g., High-Strength Interstitial-Free (HSIF). To provide new experimental data for the development of thermodynamic databases and solidification models for P alloyed steel grades, phase equilibria in the Fe-P and Fe-C-P key systems were studied up to 1550 °C using differential scanning calorimetry (DSC) and high temperature laser scanning confocal microscopy (HT-LSCM). Special focus was placed on solid/liquid equilibrium temperatures in the Fe-rich part of the binary Fe-P system between 0.025 and 9 wt pct P. In the ternary system, three isoplethal sections with 0.10 mass pct. P, 0.20 mass pct. C and constant mass percent ratio P/C of 2 were investigated. In the latter section, HT-LSCM observations were linked with DSC signals to optically identify present phase stabilities. Particularly at [pct P] < 1, significant differences between performed measurements and calculated phase equilibrium temperatures using thermodynamic assessments from the literature were identified. In all ternary sections, the experiments indicate less influence of P on the hypo-peritectic range compared to the thermodynamic calculations.

Bilateral Langerhans Cells Histiocytosis in the Temporal Bone: A case report

Langerhans cells histiocytosis (LCH) or histiocytosis-X is a rare group diseases that includes three overlapping diseases of Hand-Schuller-Christian disease (HSC), Letterer-Siwe disease (LS)and Eosinophilic granuloma(EG). It results from clonal proliferation of histiocytes having similar morphology and immunophenotype to Langerhans cells in skin and mucosa Though head and neck manifestation is common, isolated simultaneous bilateral temporal bone Langerhans Cell Histiocytosis is an extremely rare presentation. Having same otological menifestations, high resolution CT scan is advocated for early identification and differentiation of LCH from other common conditions such as mastoidits,otitis externa ,chronic suppurative otitis media. Diagnosis of LCH is confirmed by biopsy and immunohistochemical staining of S-100 protein and or CD1a antigen. Chemotherapy is main mode of treatment.The prognosis is worse when presenting age of children is younger than 2 years.&#x0D; Bangladesh J Otorhinolaryngol; April 2020; 26(1): 68-72

Chemical vs. mechanical microstructure evolution in drying colloid and polymer coatings

Colloidal based films have been widely developed for a wide range of applications including chemical and electrical barrier coatings, photonic materials, biomaterials, and pharmaceutical oral drug delivery. Many previous studies investigate methods to generate uniformity or desired stratification of the final components with a desired microstructure. Few studies have been able to investigate this microstructure in-situ during drying. This experimental study directly tracks fluorescent colloids that are either stable in suspension or have attractive interactions during the drying process using high speed laser scanning confocal microscopy to obtain details of microstructural evolution during drying. The colloidal microstructure in stable suspensions evolves continuously during drying. Microstructures in these systems have a signature Voronoi polyhedra distribution that is defined by lognormal curve having a constant standard deviation that only depends on its chemical composition. Those formulations having strongly attractive constituents have microstructure that is heterogeneous and non-monotonic due to the mechanics associated with internal convection and capillary forces. Toward the end of drying, the influence of the mode of microstructure rearrangements remains evident.

English

English

Multi-Spectroscopic Approach for the Non-invasive Characterization of Paintings on Metal Surfaces.

The aim of this study is to propose a non-invasive multi-spectroscopic approach for the characterization of oil painting artworks that use a copper plates as substrate in place of a canvas. Indeed, in the last decade, many studies have been conducted on artworks made of single materials (e.g., paintings, stones, metals). However, the characterization and conservation of composite artifacts has never be fully investigated even though many masterpieces were created using this particular technique. In this work, several spectroscopic techniques such as Infrared Spectroscopy (FTIR), Energy-Dispersive X-Ray Fluorescence spectroscopy (EDXRF), and high spatial resolution Field Emission Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (EDS), and Optical Microscopy (OM) were performed. The obtained results allowed to fully characterize the micro-chemical and microstructural features of the painted surfaces and of the metal plate. Particularly effective was the use of MA-XRF, resulting in the chemical map of the painted surfaces. Furthermore, traces of the mechanical preparation of the plate were found under the painted layers. Finally, the interface area between the paint film and the metallic support was characterized at a micro scale. This was particularly important in order to identify the degradation products formed by the interaction between the fatty acids of the binder and copper-based substrates.

Imaging features of the initial chest high resolution CT scan in juvenile patient with coronavirus disease 2019

The coronavirus disease 2019 (COVID-19) was confirmed by nucleic acid test in 15 juvenile patients aged 4-17 years in Hangzhou Xixi Hospital from January 24 to February 10, 2020. The clinical data and the initial chest high resolution CT (HRCT) findings were retrospectively analyzed.Among 15 cases, 8 patients with a mean age of (6.5±2.3) years (4-11 year) had normal HRCT manifestations (mild disease), while 7 patients with a mean age of (11.9±3.0) years (7-17 years) showed abnormal manifestations (moderate disease). In the 7 moderate cases the CT findings included local thickening of bronchial wall in 2 cases, single lesion in 1 case, bilateral pulmonary lesions in 4 cases. There were total 11 lesions, 6 of which were ground glass and slightly high-density nodules, 5 of which were speckled ground glass and 2 with a little consolidation. There were 10 subpleural lesions, including 7 in the lower lobe of the two lungs, and 1 non-subpleural lesion; the thickened local bronchioles were observed in 3 cases. None of them had hilum and mediastinal lymph node enlargement or pleural effusion. Key words: Coronavirus infection; Coronavirus disease 2019; Minors; Tomography, X-ray computed; Diagnosis

Groove Formation in Glass Substrate by a UV Nanosecond Laser

This study reports the laser grooving of glass. In this study, an ultraviolet (UV) nanosecond laser is used to produce grooves in soda lime glass by varying laser power, scan speed, pulse repetition rate, and number of scans. The threshold power density to generate damage on glass surface is found to be ~6.37 × 108 W/cm2. According to the result of a single laser scan, at a high laser power and low scan speed, material removal does not nearly occur, and only volume melting underneath the glass surface and large thermal crack are induced. With the decreasing laser power and increasing scan speed, a groove with a smooth surface is formed owing to the melting-dominant material removal process. The groove of rough surface morphology is produced with the further increase of the scan speed due to shattering induced by shock wave. Under this condition, it is found that either small cracks are produced or a crack-free groove is obtained. In this study, the fabrication of the microchannel for bio-chip application is also attempted by multiple laser scans. The near rectangular-shaped and crack-free groove (width × depth: ~220 μm × ~500 μm) with quite a smooth surface is fabricated by the multiple laser scans with a non-zero scan spacing.

Abstract 19: Default Mode Network Alterations in Cerebral Amyloid Angiopathy: A Resting State FMRI Study

Introduction: Cerebral amyloid angiopathy (CAA) is an established cause of intracerebral hemorrhage and vascular dysfunction leading to ischemia. Functional connectivity analysis using MRI is becoming an important tool to analyze the brain activity during resting state, the default mode network (DMN) representing the prototypical set of connections. As CAA pathology has a posterior predominance, we sought to characterize the functional connectivity of the posterior DMN at resting state in patients with CAA. Methods: Patients with probable CAA diagnosed using Boston Criteria and healthy controls (HC) were prospectively enrolled and received high resolution 3T MRI scans including dedicated resting-state fMRI sequences. Functional seed-to-seed analyses were done using the default processing pipeline in the CONN Toolbox. Correlation maps between the established DMN and specific regions of the posterior DMN, the precuneus and posterior cingulate, were averaged within groups and compared in an ANCOVA model. Results: Study participants consisted of 60 patients with probable CAA and 20 healthy controls [aged 69 ± 7.5 vs 72.3 ± 8 years, P = 0.108]. Seed-to-seed analysis revealed a significantly lower strength of DMN connectivity in CAA when compared to controls in the precuneus [ P = 0.009] and posterior cingulate [ P = 0.003] adjusted for age and sex (Fig 1). Conclusion: Patients with CAA exhibited significant loss of connectivity in the posterior regions of the DMN when compared to controls. The precuneus and posterior cingulate are core regions of the DMN with reportedly high metabolic rates at rest. Disruption of these posterior DMN regions might occur due to vascular amyloid pathology that shows a predominantly posterior distribution.

Rendering hydrophobic nanoclusters water-soluble and biocompatible.

Hydrophobic and hydrophilic nanoclusters embody complementary superiorities. The means to amalgamate these superiorities, i.e., the atomic precision of hydrophobic clusters and the water dissolvability of hydrophilic clusters, remains challenging. This work presents a versatile strategy to render hydrophobic nanoclusters water-soluble—the micellization of nanoclusters in the presence of solvent-conjoined Na+ cations—which overcomes the above major challenge. Specifically, although [Ag29(SSR)12(PPh3)4]3− nanoclusters are absolutely hydrophobic, they show good dissolvability in aqueous solution in the presence of solvent-conjoined Na+ cations (Na1(NMP)5 or Na3(DMF)12). Such cations act as both counterions of these nanoclusters and surface cosolvent of cluster-based micelles in the aqueous phase. A combination of DLS (dynamic light scattering) and aberration-corrected HAADF-STEM (high angle annular dark field detector scanning transmission electron microscopy) measurements unambiguously shows that the phase-transfer of hydrophobic Ag29 into water is triggered by the micellization of nanoclusters. Owing to the excellent water solubility and stability of [Ag29(SSR)12(PPh3)4]3−[Na1(NMP)5]3+ in H2O, its performance in cell staining has been evaluated. Furthermore, the general applicability of the micellization strategy has been verified. Overall, this work presents a convenient and efficient approach for the preparation of cluster-based, biocompatible nanomaterials.

Research On Distributed Vulnerability Scanning Technology Based On Web Cross-Domain Authentication Architecture

In order to carry out vulnerability detection to improve the security of the network, a distributed vulnerability scanning technology under the Web cross-domain authentication architecture based on physical link reconstruction and association spectrum feature extraction is proposed. Firstly, the distributed network vulnerability information sampling model is constructed. Then, the virtual reconstruction model of distributed network vulnerability is established. The distributed network transmission channel equalisation design under the Web cross-domain authentication architecture, and the hybrid compression perception of distributed vulnerabilities are carried out. The validity features of distributed network vulnerability information are extracted by correlation spectrum feature extraction, and the distributed vulnerability scanning under the Web cross-domain authentication architecture is realised according to the results of feature extraction. The simulation results show that the method proposed in this paper has high accuracy and scanning accuracy, and improves the distributed vulnerability monitoring ability under the Web cross-domain authentication architecture.

高速扫描激光共聚焦显微内窥镜图像校正

高速扫描激光共聚焦显微内窥镜图像校正

Study Experimental and Numerical Simulations of the Micro-hardness Tests in AL-FE alloy in Different Laser Beam Scanning

In the Al–2.0 wt.%Fe alloy the laser surface remelting (LSR) treatment was executed to investigate the treated and untreated layers areas, at different laser beam scanning, among them, 80, 100 and 120 mm/s, to respect, was presented and discussed about microstructural characteristics using the FEG and EDS techniques, and numerical experiments of pyramidal indentations of the LSR-treated systems were conducted using the FEM method. In the sample-treated cross-sectional area, the microstructure presented a columnar growth characteristic, a lot of nano-porosities and large size of the molten pool geometry in low laser beam scanning, however, in high laser beam scanning, the microstructure consisted of a cellular arrangement or fine-grained microstructure, the nano-porosities concentration and the molten pool geometry are slightly decreased. Besides, the micro-hardness in the LSR-treated area increased slightly as a function of increase of the laser beam scanning, but, the micro-hardness was much higher than the untreated sample. Meanwhile, modeling of indentation on COMSOL of the LSR-treatment by finite element method of the micro-hardness was successfully calculated. Therefore, a good agreement was found between experimental and simulated data.

Weight-bearing Imaging in Adolescent Idiopathic Scoliosis.

This article reviews the weight-bearing imaging methods in the diagnosis and monitoring of patients with adolescent idiopathic scoliosis (AIS), a three-dimensional (3D) deformity of the spine with unknown etiology. The apical vertebrae in AIS rotate away from the midline in a complex 3D pattern that formerly could only be appreciated by computed tomography (CT). Despite its superb anatomical delineation, CT is not ideal due to high radiation and scanning in either the supine or prone position; hence the full effect of gravity on the spinal curvature cannot be assessed. The introduction of low-dose stereoradiography with the capacity of 3D reconstruction has recently opened up a new era of assessment of the scoliotic spine in the upright position at multiple time points during the preoperative and postoperative period. The handheld 3D ultrasound imaging system also provides a radiation-free alternative for close monitoring for disease progression and treatment outcomes for AIS. Upright magnetic resonance imaging is radiation free and superb for the assessment of spinal cord and intervertebral disks; however, its utilization in scoliosis is limited by high cost and limited availability.

Reduced thalamic volume is strongly associated with electrical status epilepticus in sleep.

To identify the relationship between thalamic volume and electrical status epilepticus in sleep (ESES). We analyzed subcortical gray matter volumes in patients with an ESES pattern on their electroencephalographs. All magnetic resonance imaging scans were considered within normal limits. The patients were not receiving antiepileptic drug at the time of the MRI study. High resolution T1-weighted 3-dimensional MPRAGE scans were assessed for segmentation and quantitative volumetric analysis of the brain by using the "volBrain" method. After correcting for total brain volume, volumes were compared with a group of healthy controls (HCs) and patients with benign childhood epilepsy with centrotemporal spikes (BECTS). Fifteen patients with ESES, 15 patients with BECTS, and 30 HCs were included. The median age of the patients with ESES was 8.5 (range, 5.8-13) years, 8 (range, 5-14) years for the HCs, and 7.8 (range, 4-13.5) years for the patients with BECTS. The total relative thalamic volume was significantly lower in patients with ESES than in the healthy controls (0.87 ± 0.07 vs. 0.93 ± 0.03, p = 0.002), and in patients with ESES than in those with BECTS (0.87 ± 0.07 vs. 0.93 ± 0.03, p = 0.006). There was no significant difference the HCs and patients with BECTS (0.93 ± 0.03 vs. 0.93 ± 0.03, p = 0.999). Both right and left relative thalamic volumes were lower in patients with ESES than in HCs (right thalamus: 0.43 ± 0.04 vs. 0.46 ± 0.02, p = 0.003, left thalamus: 0.44 ± 0.03 vs. 0.47 ± 0.02, p = 0.002), in patients with ESES than in patients with BECTS (right thalamus: 0.43 ± 0.04 vs. 0.46 ± 0.01, p = 0.01, left thalamus: 0.43 ± 0.04 vs. 0.47 ± 0.01, p = 0.007); however, there was no significant difference between the HCs and patients with BECTS (right thalamus: 0.46 ± 0.02 vs. 0.46 ± 0.01, p = 0.999, left thalamus: 0.47 ± 0.02 vs. 0.47 ± 0.01, p = 0.999). This study highlights the association between thalamic involvement and ESES, even when not severe enough to cause a detectable lesion on visual interpretation of MRI.

EARLY DIGNOSIS OF INTERTITIAL LUNG DISEASE WITHOUT OPEN LUNG BIOPSY

Background: &#x0D; Objective : The primary objective of this study was to diagnose interstitial lung disease in patients with thorough clinical history, physical exam, chest radiograph, high resolution CT scan, pulmonary function tests (without open lung biopsy) for early diagnosis of disease and to reduce the progression of disease.&#x0D; Design: This was a Cross sectional study, patients of ILD were selected and studied during the period from November 2017 - December2018)&#x0D; Setting: Department of Pulmonary Medicine, Shadan Institute of Medical Sciences&#x0D; Duration: One year (patients of ILD were selected and studied during the period from November 2017 - December2018)&#x0D; Participants: 69 Patients with ILD attending department of Pulmonary Medicine, Shadan Institute of Medical Sciences. Hyderabad, Telangana.&#x0D; Methods: Patients with ILD were included in the study. Radiologic, spirometric evaluation was done and the results are statistically analyzed.&#x0D; Results: Most common form ILD observed was IPF (37.2%) and collagen vascular disease (5.1%). Majority of cases belonged to the age groups 41-50yrs (26%) and 51 -60 yrs (26%). Most of the cases were males (63.7%) and dyspnoea (100%) on exertion and cough (97%) were the most common presenting features. In reference to radiological abnormalities most common pattern observed is honey combing (45.8%) and ground glass (15.2%) &amp; reticular in (13.5%) of patients. 63.6% of cases of IPF and 33 % of RA-ILD showed honey combing features. Associated features like shaggy cardiac borders, elevated domes of diaphragm and lymphadenopathy, pleural reaction were observed in 42.4% of patients. The Zonal distribution of the disease on chest X-ray showed that (6.8%) of patients involve mid and lower zones. Only lower zones were involved in 23.7 % subjects and mid-zone in 1.7%. Involvement of all zones was observed in 64.4 % of cases. Spiro metric function was observed in subjects. Restrictive defect was observed in 81.3 % of patients and mixed defect was observed in 18.6 % patients.&#x0D; Conclusion: HRCT is significantly superior to chest radiography in identifying and determining the correct diagnosis of ILD. A confident clinical diagnosis of IPF can be reliably made in the presence of characteristic HRCT and clinical findings. However small subset of young patients who are progressing the disease with rapid deterioration may require invasive tests like trans bronchial lung biopsy to rule out infective process or malignancy&#x0D; Keywords: Interstitial Lung Disease, Diagnosis, Clinical Methods.

108. Posterior bone graft options and success in single-level circumferential lumbar fusions

BACKGROUND CONTEXT Achieving spinal fusion requires bone graft and is most reliable using an anterior/posterior technique. Anterior fusion, due to the large bony surface area between the vertebral bodies, results in reliable fusion. Instrumentation which provides stability, also increases the fusion rate. The bone graft for the posterior fusion may come from a variety of sources. Historically, bone graft was obtained from the iliac portion of the patient's own pelvis, IBG, but this may result in additional postoperative pain. Alternatives are currently the most common form of bone graft, but there is very little knowledge as to the superiority of one alternative over another. PURPOSE To determine the ability to achieve a solid posterior spinal fusion using sources of bone graft derived from IBG, bone morphogenic protein (BMP), or from donor bone combined with stem cells derived from either autologous bone marrow aspirate (BMA) or donor bone, fat, or amniotic membrane/fluid. STUDY DESIGN/SETTING Prospective randomized single-blinded clinical study of 6 comparative groups with 27 patients in each group. PATIENT SAMPLE Adults with advanced degenerative disc disease (DDD) who underwent single-level lumbar spinal fusion. OUTCOME MEASURES Outcomes included self-assessment of back and leg pain, pain drawing, ODI, pain medication usage, and procedure success. High resolution CT scans at one year postoperative assessed fusion rates between groups. Costs of graft materials were compared. METHODS Outcomes were obtained prospectively. Patients were enrolled over a 7-year period and followed for 2-4 years. All single-level circumferential fusions used BMP anteriorly, instrumentation, and patients were randomized into 6 groups with a different type of bone-graft used posteriorly. RESULTS CT scans found solid interbody fusion in 98% of patients. However, solid posterior fusions varied between groups: 98% IBG, 94% BMP, 78% concentrated BMA, 70% bone allograft stem cells, and 64% each for amniotic tissue and fat derived stem cells. Clinical improvement was significant from preop to 2-4 year follow-up within all groups (p CONCLUSIONS One-level circumferential spinal fusion using IBG was the most reliable and cost-effective graft material. BMP was highly effective and the most expensive. Concentrated autologous BMA had moderate fusion success and cost. Allograft products with varying cellularity were marginally effective for their high cost. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

972-P: Expanded Real-World Use Reaffirms Strong Correlation between Scanning Frequency of Flash Glucose Monitoring and Glucose Control

Previous analysis of real-world flash glucose monitoring data showed a strong correlation between higher scan frequency and improved glucose control. Robust adoption since then has resulted in a ten-fold increase in data available to confirm these findings. Deidentified data between September 2014 to September 2018, comprising of 592,328 readers and 5,842,193 sensors worldwide, were analyzed. Scan rate per reader was determined and each reader was sorted into twenty equally-sized rank-ordered groups, categorized by scan frequency. Glucose parameters were calculated for each group, including estimated HbA1c, time above, below and within range identified as 70 -180 mg/dL. Users performed an average of 12 scans per day (median:10, interquartile range: 7-14) with a total of 1.71 billion hours of readings and 896 million scans. The estimated HbA1c decreased from 8.2% to 6.7% (66.2 to 50.0 mmol/mol) as scan rate increased from lowest to highest scan groups (3.5 and 38.5 scans/day, respectively; p &amp;lt; 0.001). The time below 54 mg/dL decreased by 26% (p &amp;lt; 0.001), from 31.6 to 23.4 min/day. Time above 240 mg/dL decreased from 5.9 to 2.2 h/day (63%, p &amp;lt; 0.001). Time in range increased from 11.7 h/day to 16.8 h/day (43%, p &amp;lt; 0.001). Overall, 63.0% of readers had time in range &amp;gt;12 hours/day, while comparing those below and above 10 scans per day were 52.1% and 73.1%, respectively. The expanded real-world analysis confirms prior observations that higher rates of scanning to self-monitor glucose strongly correlate with improved glucose measures, including decreased mean glucose and time in hyper- and hypoglycaemia as well as increased time in range. Disclosure J. Lang: Employee; Self; Abbott. S. Jangam: Employee; Self; Abbott Laboratories. Employee; Spouse/Partner; Abbott Laboratories. T. Dunn: Employee; Self; Abbott Laboratories. G. Hayter: Employee; Self; Abbott.