Carotid Artery Imaging Research Articles

Correlation Between Internal Carotid Artery Tortuosity and Imaging of Cerebral Small Vessel Disease.

Background and Purpose: An association between artery tortuosity and neuroimaging of cerebral small vessel disease (SVD) has been reported, especially in the posterior circulation. However, few studies involved the whole magnetic resonance imaging (MRI) spectrum of SVD in association with anterior circulation arterial tortuosity. This study aimed to investigate the relationship between internal carotid artery (ICA) tortuosity and the neuroimaging of SVD.Methods: Data of 1,264 consecutive patients in whom cerebral vessel diseases were suspected and who underwent both MRI and computed tomography angiography were reviewed from a prospective registry. Internal carotid artery tortuosity was evaluated using the tortuosity index (TI), which was defined as the ratio of the vessel centerline length divided by the straight length. Magnetic resonance imaging was used to assess cerebral microbleeds (CMBs), white matter hyperintensities (WMHs), enlarged perivascular spaces (EPVSs), and lacunes.Results: The TIs of the ICA for patients with and without SVD MRI markers were 1.81 ± 0.42 and 1.72 ± 0.33, respectively (P < 0.001). Univariate analysis showed that the ICA TI were positively correlated with each SVD MRI marker (P < 0.001), and the correlation coefficients (rs) were 0.57, 0.42, 0.30, and 0.26 for EPVSs, WMHs, CMBs, and lacunes, respectively. The adjusted ORs of the ICA TI were 1.52 (95% CI 1.44–1.60, P < 0.001) for EPVS grade 1, 2.05 (95% CI 1.93–2.18, P < 0.001) for EPVS grades 2–4, and 1.09 (95% CI 1.03–1.15, P = 0.004) for WMH grade 3.Conclusions: The TI of ICA was higher in patients with neuroimaging of SVD. Internal carotid arteries tortuosity was associated with MRI-defined markers of SVD, including EPVS and high-grade WMH, and positively correlated with EPVS severity. Arterial tortuosity might be a risk factor for SVD. This finding may have potential clinical significance for identifying patients with suspected SVD.

Toward improved 3D carotid artery imaging with Adaptive CaRdiac cOne BEAm computed Tomography (ACROBEAT).

Interventional treatments of aneurysms in the carotid artery are increasingly being supplemented with three-dimensional (3D) x-ray imaging. The 3D imaging provides additional information on device sizing and stent malapposition during the procedure. Standard 3D x-ray image acquisition is a one-size fits all model, exposing patients to additional radiation and results in images that may have cardiac-induced motion blur around the artery. Here, we investigate the potential of a novel dynamic imaging technique Adaptive CaRdiac cOne BEAm computed Tomography (ACROBEAT) to personalize image acquisition by adapting the gantry velocity and projection rate in real-time to changes in the patient's electrocardiogram (ECG) trace. We compared the total number of projections acquired, estimated carotid artery widths and image quality between ACROBEAT and conventional (single rotation fixed gantry velocity and acquisition rate, no ECG-gating) scans in a simulation study and a proof-of-concept physical phantom experimental study. The simulation study dataset consisted of an XCAT digital software phantom programmed with five patient-measured ECG traces and artery motion curves. The ECG traces had average heart rates of 56, 64, 76, 86, and 100bpm. To validate the concept experimentally, we designed and manufactured the physical phantom from an 8-mm diameter silicon rubber tubing cast into Phytagel. An artery motion curve and the ECG trace with an average heart rate of 56bpm was passed through the phantom. To implement ACROBEAT on the Siemens ARTIS pheno angiography system for the proof-of-concept experimental study, the Siemens Test Automation Control System was used. The total number of projections acquired and estimated carotid artery widths were compared between the ACROBEAT and conventional scans. As the ground truth was available for the simulation studies, the image quality metrics of Root Mean Square Error (RMSE) and Structural Similarity Index (SSIM) were also utilized to assess image quality. In the simulation study, on average, ACROBEAT reduced the number of projections acquired by 63%, reduced carotid width estimation error by 65%, reduced RMSE by 11% and improved SSIM by 27% compared to conventional scans. In the proof-of-concept experimental study, ACROBEAT enabled a 60% reduction in the number of projections acquired and reduced carotid width estimation error by 69% compared to a conventional scan. A simulation and proof-of-concept experimental study was completed applying a novel dynamic imaging protocol, ACROBEAT, to imaging the carotid artery. The ACROBEAT results showed significantly improved image quality with fewer projections, offering potential applications to intracranial interventional procedures negatively affected by cardiac motion.

Fully Automatic Measurement of Intima-Media Thickness in Ultrasound Images of the Common Carotid Artery Based on Improved Otsu's Method and Adaptive Wind Driven Optimization.

The intima media thickness (IMT) of the common carotid artery (CCA) can be used to predict the risk of atherosclerosis. Many image segmentation techniques have been used for IMT measurement. However, severe noise in the ultrasound image can lead to erroneous segmentation results. To improve the robustness to noise, a fully automatic method, based on an improved Otsu's method and an adaptive wind-driven optimization technique, is proposed for estimating the IMT (denoted as "improved Otsu-AWDO"). First, an advanced despeckling filter, i.e., " Nagare's filter" is used to address the speckle noise in the carotid ultrasound images. Next, an improved fuzzy contrast method (IFC) is used to enhance the region of the intima media complex (IMC) in the blurred filtered images. Then, a new method is used for automatic extraction of the region of interest (ROI). Finally, the lumen intima interface and media adventitia interface are segmented from the IMC using improved Otsu-AWDO. Then, 156 B-mode longitudinal carotid ultrasound images of six different datasets are used to evaluate the performance of the automatic measurements. The results indicate that the absolute error of proposed method is only 10.1 ± 9.6 (mean ± std in μm). Moreover, the proposed method has a correlation coefficient as high as 0.9922, and a bias as low as 0.0007. From comparison with previous methods, we can conclude that the proposed method has strong robustness and can provide accurate IMT estimations.

Assessment of the Protocol-Guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) Program for Improving Quality of Care for Transient Ischemic Attack

Patients with transient ischemic attack (TIA) are at high risk of recurrent vascular events. Timely management can reduce that risk by 70%; however, gaps in TIA quality of care exist. To assess the performance of the Protocol-Guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) intervention to improve TIA quality of care. This nonrandomized cluster trial with matched controls evaluated a multicomponent intervention to improve TIA quality of care at 6 diverse medical centers in 6 geographically diverse states in the US and assessed change over time in quality of care among 36 matched control sites (6 control sites matched to each PREVENT site on TIA patient volume, facility complexity, and quality of care). The study period (defined as the data period) started on August 21, 2015, and extended to May 12, 2019, including 1-year baseline and active implementation periods for each site. The intervention targeted clinical teams caring for patients with TIA. The quality improvement (QI) intervention included the following 5 components: clinical programs, data feedback, professional education, electronic health record tools, and QI support. The primary outcome was the without-fail rate, which was calculated as the proportion of veterans with TIA at a specific facility who received all 7 guideline-recommended processes of care for which they were eligible (ie, anticoagulation for atrial fibrillation, antithrombotic use, brain imaging, carotid artery imaging, high- or moderate-potency statin therapy, hypertension control, and neurological consultation). Generalized mixed-effects models with multilevel hierarchical random effects were constructed to evaluate the intervention associations with the change in the mean without-fail rate from the 1-year baseline period to the 1-year intervention period. Six facilities implemented the PREVENT QI intervention, and 36 facilities were identified as matched control sites. The mean (SD) age of patients at baseline was 69.85 (11.19) years at PREVENT sites and 71.66 (11.29) years at matched control sites. Most patients were male (95.1% [154 of 162] at PREVENT sites and 94.6% [920 of 973] at matched control sites at baseline). Among the PREVENT sites, the mean without-fail rate improved substantially from 36.7% (58 of 158 patients) at baseline to 54.0% (95 of 176 patients) during a 1-year implementation period (adjusted odds ratio, 2.10; 95% CI, 1.27-3.48; P = .004). Comparing the change in quality at the PREVENT sites with the matched control sites, the improvement in the mean without-fail rate was greater at the PREVENT sites than at the matched control sites (36.7% [58 of 158 patients] to 54.0% [95 of 176 patients] [17.3% absolute improvement] vs 38.6% [345 of 893 patients] to 41.8% [363 of 869 patients] [3.2% absolute improvement], respectively; absolute difference, 14%; P = .008). The implementation of this multifaceted program was associated with improved TIA quality of care across the participating sites. The PREVENT QI program is an example of a health care system using QI strategies to improve performance, and may serve as a model for other health systems seeking to provide better care. ClinicalTrials.gov Identifier: NCT02769338.

Segmentation of the Common Carotid Intima-Media Complex in Ultrasound Images Using 2-D Continuous Max-Flow and Stacked Sparse Auto-encoder

The intima-media thickness (IMT) of a common carotid artery in an ultrasound image is considered an important indicator of the onset of atherosclerosis. However, it is challenging to segment the intima-media complex (IMC) directly in ultrasound images. This study proposes a fully automatic method to segment the IMC on longitudinal B-mode ultrasound images. Our method consists of two stages: (i) extraction of the region of interest with a continuous max-flow algorithm and region-of-interest reconstruction using a stacked sparse auto-encoder model, and (ii) IMC segmentation using a trained random forest classifier. The proposed method has been tested on three databases from three different imaging centres, comprising a total of 228 ultrasound images of the common carotid artery. On the three databases, our method yields mean absolute errors of 0.028 ± 0.016 mm, 0.579 ± 0.288 pixel and 0.582 ± 0.341 pixel; polyline distance (PD) measures of 0.026 ± 0.017 mm, 0.657 ± 0.275 pixel and 0.731 ± 0:282 pixel; Hausdorff distance measures of 0.249 ± 0.101 mm, 4.760 ± 1.085 pixels and 5.825 ± 2.059 pixels; and correlation coefficients of 95.19%, 93.79%, and 98.96%, respectively. These results indicate that the proposed method performs well in segmentation of the IMC and measurement of the IMT.

Co-registration of Intravascular Ultrasound With Angiographic Imaging for Carotid Artery Disease

Intravascular ultrasound (IVUS) provides endoluminal views and cross-sectional images of carotid arteries but lacks overview of vascular territory provided by angiography. Co-registration of IVUS with angiographic images may provide the potential to navigate both imaging modalities in a synchronous manner. The objective of this study is to evaluate the feasibility and accuracy of co-registering both imaging modalities in the carotid vasculature of the neck. Fourteen patients with 15 cervical carotid artery lesions underwent angiography and subsequent treatment. In each case, an IVUS catheter was advanced to the target lesion and a reference angiography sequence was acquired. This was followed by an electrocardiography-triggered fluoroscopy sequence that was initiated upon IVUS catheter pullback. IVUS data collected during pullback were registered with fluoroscopy and evaluated for error and clinical usability. A total of 32 landmarks were identified that demonstrated reasonable agreement during IVUS-angiography co-registration. There was a mean registration error distance of 3.36 mm (SD 2.82 mm) between targets. The longitudinal extent and severity of the disease through the target segment could be easily evaluated after co-registration. Semiautomatic tracking and co-registration of angiography and IVUS is a new technology and has the potential to increase the use of IVUS in carotid disease and to proivde the opportunity to optimize procedural outcomes.

Photon-counting CT with tungsten as contrast medium: Experimental evidence of vessel lumen and plaque visualization

Background and aimsWe aimed to investigate the potential of a preclinical photon-counting detector CT (PCT) scanner with an experimental tungsten-based contrast medium for carotid artery imaging. MethodsA carotid artery specimen was imaged on a PCT system using the multi-energy bin option (pixel size 0.5 × 0.5 mm2; tube voltage 140 kVp, contrast media-dependent energy thresholds: iodine 20, 75 keV; tungsten 20, 68 keV) at two radiation doses (CTDIvol of 100 mGy and 10 mGy) with iodine and tungsten as contrast media at equal mass-concentrations. Standard CT, virtual non-calcium (VNCa) and calcium-only images were reconstructed. Subjective image quality (4-point Likert scale) was rated using histology as reference. Noise and attenuation measurements were performed. Simulations were conducted to assess the material-decomposition efficiency for different object diameters. ResultsImage quality on VNCa images was significantly higher for tungsten at lower dose (reader 1/reader 2: 2, [2,2]/2, [2,2] vs 1.5, [2,1]/1, [1,1.75], p < 0.05). Noise was significantly lower at both dose levels for tungsten VNCa images as compared to iodine images (higher dose: tungsten 24 vs iodine 31; lower dose: tungsten 60 vs iodine 82; both p < 0.01). Simulations indicated improved material-decomposition efficiency for tungsten than for iodine pronounced at smaller object diameters. ConclusionsPCT employing the multi-energy bin option in combination with tungsten as contrast media enables improved carotid artery imaging with respect to lumen and plaque visualization and image noise.

Improved selective visualization of internal and external carotid artery in 4D-MR angiography based on super-selective pseudo-continuous arterial spin labeling combined with CENTRA-keyhole and view-sharing (4D-S-PACK)

PurposeFour-dimensional magnetic resonance angiography (4D-MRA) based on super-selective pseudo-continuous arterial spin labeling, combined with Keyhole and View-sharing (4D-S-PACK) was introduced for scan-accelerated vessel-selective 4D-MRA. Label selectivity and visualization effectiveness were assessed. MethodsNine healthy volunteers were included in the study. The label selectivity for the imaging of internal carotid artery (ICA) and external carotid artery (ECA) circulation was assessed qualitatively. The contrast-to-noise ratio (CNR) in 4D-S-PACK was measured in four middle cerebral artery (MCA) and superficial temporal artery (STA) segments and compared with that in contrast-inherent inflow-enhanced multi-phase angiography combined with the vessel-selective arterial spin labeling technique (CINEMA-select). Vessel-selective arterial visualization in 4D-S-PACK was assessed qualitatively in a patient with dural arteriovenous fistula and compared with digital subtraction angiography (DSA) and non-vessel selective 4D-PACK. Results4D-S-PACK vessel selectivity was judged to be at a clinically acceptable level in all cases except one ECA-targeted label. The CNR was significantly higher using 4D-S-PACK compared with CINEMA-select in MCA and STA peripheral segments (p < 0.001). In patient examination, territorial flow visualization in feeding artery and draining vein circulation on 4D-S-PACK were comparable with that on DSA and the identification of such responsible vessels was easier on 4D-S-PACK than on 4D-PACK. Conclusion4D-S-PACK showed high vessel-selectivity and higher visualization effectiveness compared with CINEMA-select. One clinical case was performed and ICA and ECA territorial flow was successfully visualized separately, suggesting clinical usefulness.

Intimointimal Intussusception in Acute Aortic Dissection.

HomeRadiology: Cardiothoracic ImagingVol. 2, No. 4 PreviousNext Images in Cardiothoracic ImagingFree AccessVascular ImagingIntimointimal Intussusception in Acute Aortic DissectionLucas de Pádua Gomes de Farias , João Manoel Miranda Magalhães Santos, Gustavo Borges da Silva Teles, Luciana de Pádua Silva BaptistaLucas de Pádua Gomes de Farias , João Manoel Miranda Magalhães Santos, Gustavo Borges da Silva Teles, Luciana de Pádua Silva BaptistaAuthor AffiliationsFrom the Hospital Samaritano Paulista, Avenida Brigadeiro Luís Antônio, 1895-Bela Vista, São Paulo, SP, CEP 01317-002, Brazil.Address correspondence to L.d.P.G.d.F. (e-mail: [email protected]).Lucas de Pádua Gomes de Farias João Manoel Miranda Magalhães SantosGustavo Borges da Silva TelesLuciana de Pádua Silva BaptistaPublished Online:Aug 27 2020https://doi.org/10.1148/ryct.2020200023MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In Intimointimal intussusception in aortic dissection is a rare but potentially life-threatening type of complication (1). The intimal tear and delamination process occur circumferentially, and the intimal flap separates from the aorta, partially or totally, with the detached tissue forced downstream. Furthermore, the intussuscepted flap can obstruct the aortic arch and its branches (1–3). Lack of typical imaging findings of type A aortic dissection can be a challenge due to the absence of intimal flap in the ascending aorta (1,3) (Figure).CT angiographic images (A–C, axial multiplanar reformations [MPRs]; D, sagittal oblique; E, MPR extended; F, axial oblique; G, coronal; and H, oblique maximum intensity projection) show Stanford type A aortic dissection with an intimal flap in aortic root (arrowheads) and an intussuscepted intima (white arrow) in aortic arch, with the false lumen wrapped around the true lumen. Furthermore, no intimal flap was seen in ascending aorta (*). Right coronary artery (RCA) originates from true lumen and left main (LM) coronary artery from false lumen. Dissection also extends into the origin of the brachiocephalic trunk (black arrow) and left common carotid artery (image not included). LV = left ventricle.Download as PowerPointOpen in Image Viewer Disclosures of Conflicts of Interest: L.d.P.G.d.F. disclosed no relevant relationships. J.M.M.M.S. disclosed no relevant relationships. G.B.d.S.T. disclosed no relevant relationships. L.d.P.S.B. disclosed no relevant relationships.Keywords: Adults, Aorta, CT-Angiography, Cardiac, Carotid Arteries, Dissection, Thorax, Vascular Authors declared no funding for this work.

Performance evaluation of unpreprocessed and pre-processed ultrasound images of carotid artery using CNN algorithm

Detection of plaques is an important task especially those which are prone to rupture and may dislocate to some other body parts. Also early detection reduces the risk of cardiac and cerebrovascular anomalies. Due to its wide availability and low cost, ultrasound images of carotid artery has the ability and potential to gain the preference over other resources for plaque detection and analysis in medical practice. However, the difficulty caused in automated techniques to identify plaques is significantly due to image noise, plaque size and the complex appearance of tissues comprising a plaque. So, in this paper, we have addressed this problem by using deep learning techniques such as CNN algorithm. Here we will build a CNN (Convolutional Neural Network) that will extract features from the dataset of images thereby giving detailed information which will help the clinicians to identify the abnormalities and constituents of different plaques in an image and report the image as “normal” or “abnormal”. In this paper we have used approximately 1000 images (JPG format) of 100 cases to process and has validated the proposed convolutional neural network (CNN). The process of cross-validation with the clinical assessment showed a correlation of about 0.75 for the detection of plaque. This results indicate the potential of deep learning techniques in medical fields, here, automatic detection of anomalies in carotid ultrasound images.

Evaluation and Analysis of Cardiovascular Function in Intensive Care Unit Patients by Ultrasound Image Segmentation Based on Deep Learning

Many studies have shown that cardiovascular disease has become one of the major diseases leading to death in the world. Therefore, it is a very meaningful topic to use image segmentation technology to segment blood vessels for clinical application. In order to automatically extract the features of blood vessel images in the process of segmentation, the deep learning algorithm is combined with image segmentation technology to segment the nerve cell membrane and carotid artery images of ICU patients, and to segment the blood vessel images from a multi-dimensional perspective. The relevant data are collected to observe the effect of this model. The results show that the three-dimensional multi-scale linear filter has a good effect on carotid artery segmentation in the image segmentation of nerve cell membranes and carotid artery. When analyzing the accuracy of vascular image segmentation from network parameters and training parameters, it is found that the accuracy of the threedimensional multi-scale linear filter can reach about 85%. Therefore, it can be found that the combination of deep learning algorithm and image segmentation technology has a good segmentation effect, and the segmentation accuracy is also high. The experiment achieves the desired effect, which provides experimental basis for the clinical application of the vascular image segmentation technology.

Simulations and human cadaver head studies to identify optimal acoustic receiver locations for minimally invasive photoacoustic-guided neurosurgery

Real-time intraoperative guidance during minimally invasive neurosurgical procedures (e.g., endonasal transsphenoidal surgery) is often limited to endoscopy and CT-guided image navigation, which can be suboptimal at locating underlying blood vessels and nerves. Accidental damage to these critical structures can have severe surgical complications, including patient blindness and death. Photoacoustic image guidance was previously proposed as a method to prevent accidental injury. While the proposed technique remains promising, the original light delivery and sound reception components of this technology require alterations to make the technique suitable for patient use. This paper presents simulation and experimental studies performed with both an intact human skull (which was cleaned from tissue attachments) and a complete human cadaver head (with contents and surrounding tissue intact) in order to investigate optimal locations for ultrasound probe placement during photoacoustic imaging and to test the feasibility of a modified light delivery design. Volumetric x-ray CT images of the human skull were used to create k-Wave simulations of acoustic wave propagation within this cranial environment. Photoacoustic imaging of the internal carotid artery (ICA) was performed with this same skull. Optical fibers emitting 750 nm light were inserted into the nasal cavity for ICA illumination. The ultrasound probe was placed on three optimal regions identified by simulations: (1) nasal cavity, (2) ocular region, and (3) 1 mm-thick temporal bone (which received 9.2%, 4.7%, and 3.8% of the initial photoacoustic pressure, respectively, in simulations). For these three probe locations, the contrast of the ICA in comparative experimental photoacoustic images was 27 dB, 19 dB, and 12 dB, respectively, with delay-and-sum (DAS) beamforming and laser pulse energies of 3 mJ, 5 mJ, and 4.2 mJ, respectively. Short-lag spatial coherence (SLSC) beamforming improved the contrast of these DAS images by up to 15 dB, enabled visualization of multiple cross-sectional ICA views in a single image, and enabled the use of lower laser energies. Combined simulation and experimental results with the emptied skull and >1 mm-thick temporal bone indicated that the ocular and nasal regions were more optimal probe locations than the temporal ultrasound probe location. Results from both the same skull filled with ovine brains and eyes and the human cadaver head validate the ocular region as an optimal acoustic window for our current system setup, producing high-contrast (i.e., up to 35 dB) DAS and SLSC photoacoustic images within the laser safety limits of a novel, compact light delivery system design that is independent of surgical tools (i.e., a fiber bundle with 6.8 mm outer diameter, 2 mm-diameter optical aperture, and an air gap spacing between the sphenoid bone and fiber tips). These results are promising toward identifying, quantifying, and overcoming major system design barriers to proceed with future patient testing.

Association between magnetic resonance imaging of carotid artery and coronary stenosis detected by computed tomography angiography

To investigate the correlation between carotid artery stenosis (CAS) measured by magnetic resonance imaging (MRI) and the coronary stenosis (CS) determined by computed tomography angiography (CTA). In this prospective study, 42 subjects diagnosed with coronary artery disease (CAD) underwent MRI and CTA examinations. The severity degree and number of CAS, the score, detection rate and type of carotid plaque, and also the severity degree and number of CS were assessed. Spearman's rank correlation test was used to evaluate the correlation between CAS and CS. CS was detected in 42 (100%) subjects, while CAS was detected in 36 (85.7%) subjects. Distribution of CAS severity grades in multiple-vessel group was significantly different from other groups, which with more moderate and severe stenosis (p < 0.05). A positive and significant correlation between the CAS severity and CS severity (r = 0.612, p < 0.05), and the number of involved coronary vessels (r = 0.572, p < 0.05) were observed, respectively. Both detection rate (r = 0.587, p < 0.05) and score (r = 0.735, p < 0.05) of carotid plaque showed a good correlation with the number of involved coronary vessels. After carotid MRI, 71 carotid plaques were detected in 42 subjects, with an incidence rate of 9.9% in subjects with mild CS, 18.3% in moderate CS and 71.8% in severe CS. Correlation between CAS measured by MRI and CS determined by CTA was identified in present study. These results indicated that the non-invasive CAS evaluation employing the MRI may be clinically useful for the assessment of CS.

Increased carotid artery wall stiffness and plaque prevalence in HIV infected patients measured with ultrasound elastography.

Assess carotid artery strain and motion in people living with HIV as markers of premature aging using ultrasound noninvasive vascular elastography (NIVE). Seventy-four HIV-infected and 75 age-matched control subjects were recruited from a prospective, controlled cohort study from October 2015 to October 2017 (mean age 56years±8years; 128 men). NIVE applied to longitudinal ultrasound images of common and internal carotid arteries quantified the cumulated axial strain, cumulated shear strain, cumulated axial translation, and cumulated lateral translations. The presence of plaque was also assessed. An association between elastography biomarkers and HIV status was evaluated with Mann-Whitney tests and multivariable linear regression models. A higher occurrence of carotid artery plaques was found in HIV-infected individuals (p= 0.011). Lower cumulated lateral translations were found in HIV-infected subjects on both common and internal carotid arteries (p=0.037 and p=0.026, respectively). These observations remained significant when considering multivariable models including common cardiovascular risk factors and clinical characteristics (p<0.05). Lower cumulated axial strains were also observed in internal carotid arteries when considering both multivariable models (p<0.05). Lower translation and strain of the carotid artery wall in HIV-infected individuals indicates increased vessel wall stiffness. These new imaging biomarkers could be used to characterize premature atherosclerosis development. • Noninvasive vascular elastography (NIVE) based on ultrasound imaging quantifies translations and strains of carotid arteries. • Lower translation and strain of the carotid artery wall found in HIV-infected individuals indicate premature arterial stiffening, compared with age-matched controls. • Carotid artery plaques were more prevalent in HIV-infected individuals than in control subjects.

Abstract WP452: Nurses Use Real-Time Patient Identification Tool to Improve Care Coordination for Transient Ischemic Attack Patients

Background: Programs emphasizing early evaluation and management have reduced 70% of transient ischemic attack (TIA) patients’ recurrent events. One barrier to guideline-concordant care is inadequate care coordination. Purpose: Our objective was to evaluate adoption of nurse care coordination programs on TIA care quality at two Veteran Health Administration (VHA) facilities. Methods: Nurse care coordination programs with real-time patient identification and using Consolidated Framework for Implementation Research (CFIR) to guide local adoption, were evaluated at 2 VHA facilities. Programs were coordinated by an Emergency Department (ED) Nurse Navigator or Neurology Stroke Nurse Coordinator. The nurses used a Patient Identification Tool which was updated daily and displayed: TIA patient’s name, event and discharge dates, diagnosis, visit type (ED or inpatient), and primary care team. Nurses reviewed patients’ charts for key care components (e.g., medications), identified gaps in care, and provided follow-up. TIA care quality was evaluated by Without Fail Rate (WFR) which describes the facility-level proportion of patients who received all eligible processes of care (anticoagulation for atrial fibrillation, antithrombotics, brain imaging, carotid artery imaging, hypertension control, moderate/high intensity statin, neurology consultation). Results: We compared the WFR before (Fiscal Year [FY] 2017) and after (FY2019) implementation of the care coordination programs: Site-1, 59.6% (N=48) to 71.4% (N=30), p=0.332 (not significant); Site-2, 15.9% (N=47) to 38.5% (N=29), p=0.045 (significant). The individual process of care with greatest improvement was high/moderate potency statin at Site-1 (68.4% to 82.6%, p=0.250 [not significant]) and neurology consultation at Site-2 (39.5% to 80.8%, p=0.001 [significant]). Conclusions: Nurse care coordination programs using real-time patient identification were associated with improved quality of care. These broadly generalizable programs were important components of a comprehensive, multidisciplinary quality improvement initiative. Healthcare systems interested in improving care for TIA patients may find real-time patient identification useful in coordinating their care.

Abstract WP347: The Effectiveness and Implementation of the Protocol-Guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) Quality Improvement Program: An Exampleofa Learning Healthcare System in Action

Objectives: Transient ischemic attack (TIA) patients are at high risk of recurrent vascular events; timely management can reduce that risk by 70%. The Protocol-guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) trial evaluated the implementation of a quality improvement (QI) program aligned with Learning Healthcare System principles to improve TIA care. Methods: A facility-based, stepped-wedge trial was conducted at six diverse sites. The intervention included five components: clinical programs, data feedback, professional education, electronic health record tools, and QI support. Implementation strategies included: team activation via audit and feedback, goal setting, reflecting and evaluating, and planning; external facilitation; and building a community of practice. The primary effectiveness outcome was the Without Fail rate (WFR); proportion of TIA patients who received all processes of care for which they were eligible among: brain imaging, carotid artery imaging, neurology consultation, hypertension control, anticoagulation for atrial fibrillation, antithrombotics, high/moderate potency statins. The primary implementation outcomes were the number of improvement activities completed and the Group Organization (GO) scores for providing and improving care (scale of 1-10). Results: The 6 PREVENT facilities cared for N=162 control period TIA patients and N=191 intervention period TIA patients. The mean facility WFR increased from 36.7% (baseline) to 53.9% (active implementation); p=0.002 (adjusted for temporal trend, hospital admission). The mean number of improvement activities completed during the 1-year implementation period was 26 (range 11-39). The mean facility GO scores increased: providing care, 1.2 to 6.5; improving care, 1.0 to 6.7. Conclusions: PREVENT advances three aspects of a learning healthcare system: Learning from Data (teams interacted with their facility’s performance data to explore hypotheses, plan QI activities, and evaluate change over time); Learning from Each Other (teams participated in monthly virtual collaborative conferences), and Sharing Best Practices (teams shared tools and protocols).

Segmentation of carotid arterial walls using neural networks.

BACKGROUNDAutomated, accurate, objective, and quantitative medical image segmentation has remained a challenging goal in computer science since its inception. This study applies the technique of convolutional neural networks (CNNs) to the task of segmenting carotid arteries to aid in the assessment of pathology.AIMTo investigate CNN’s utility as an ancillary tool for researchers who require accurate segmentation of carotid vessels.METHODSAn expert reader delineated vessel wall boundaries on 4422 axial T2-weighted magnetic resonance images of bilateral carotid arteries from 189 subjects with clinically evident atherosclerotic disease. A portion of this dataset was used to train two CNNs (one to segment the vessel lumen and the other to segment the vessel wall) with the remaining portion used to test the algorithm’s efficacy by comparing CNN segmented images with those of an expert reader.RESULTSOverall quantitative assessment between automated and manual segmentations was determined by computing the DICE coefficient for each pair of segmented images in the test dataset for each CNN applied. The average DICE coefficient for the test dataset (CNN segmentations compared to expert’s segmentations) was 0.96 for the lumen and 0.87 for the vessel wall. Pearson correlation values and the intra-class correlation coefficient (ICC) were computed for the lumen (Pearson = 0.98, ICC = 0.98) and vessel wall (Pearson = 0.88, ICC = 0.86) segmentations. Bland-Altman plots of area measurements for the CNN and expert readers indicate good agreement with a mean bias of 1%-8%.CONCLUSIONAlthough the technique produces reasonable results that are on par with expert human assessments, our application requires human supervision and monitoring to ensure consistent results. We intend to deploy this algorithm as part of a software platform to lessen researchers’ workload to more quickly obtain reliable results.

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: A quantitative, controlled study using Doppler echography

ObjectiveThe underlying hypothesis in orthostatic intolerance (OI) syndromes is that symptoms are associated with cerebral blood flow (CBF) reduction. Indirect CBF measurements (transcranial Doppler flow velocities), provide inconsistent support of this hypothesis. The aim of the study was to measure CBF during a 30 min head-up tilt test (HUT), using Doppler flow imaging of carotid and vertebral arteries, in individuals with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), a condition with a high prevalence of OI. Methods429 ME/CFS patients were studied: 247 had a normal heart rate (HR) and blood pressure (BP) response to HUT, 62 had delayed orthostatic hypotension (dOH), and 120 had postural orthostatic tachycardia syndrome (POTS). We also studied 44 healthy controls (HC). CBF measurements were made at mid-tilt and end-tilt. Before mid-tilt, we administered a verbal questionnaire to ascertain for 15 OI symptoms. ResultsEnd-tilt CBF reduction was 7% in HC versus 26% in the overall ME/CFS group, 24% in patients with a normal HR/BP response, 28% in those with dOH, and 29% in POTS patients (all P < .0005). Using a lower limit of normal of 2SD of CBF reduction in HC (13% reduction), 82% of patients with normal HR/BP response, 98% with dOH and 100% with POTS showed an abnormal CBF reduction. There was a linear correlation of summed OI symptoms with the degree of CBF reduction at mid-tilt (P < .0005). ConclusionsDuring HUT, extracranial Doppler measurements demonstrate that CBF is reduced in ME/CFS patients with POTS, dOH, and even in those without HR/BP abnormalities. SignificanceThis study shows that orthostatic intolerance symptoms are related to CBF reduction, and that the majority of ME/CFS patients (90%) show an abnormal cerebral flow reduction during orthostatic stress testing. This may have implications for the diagnosis and treatment of ME/CFS patients.

Study of duplex colour doppler imaging of carotid arteries in patients with peripheral vascular disease in Telangana population

Study of duplex colour doppler imaging of carotid arteries in patients with peripheral vascular disease in Telangana population

Filtering and Detection of Intima-media Thickness (IMT) for the risk of Carotid Artery Atherosclerosis

Ultrasound images of carotid artery in brightness mode (B-mode) are used to detect the probabilities of atherosclerosis and cardiovascular diseases. They are used to measure the intima-media thickness (IMT). Ultrasound images suffer from peculiar phenomena which creates speckle (a type of noise) on the image. The speckles present in the medical images detoriates the quality of the image. This paper presents a work which is used to remove the speckles by utilizing the local characteristics of the image in the filter named as local statistics mean variance (lsmv) filter. It is a preprocessing step of medical image processing. Conventional IMT was done by locating the far walls of the carotid artery. This can be changed by applying segmentation algorithm which could automatically detect the far walls and could measure the IMT. This paper approaches towards automatic edge detection method using Prewitt operator. The objective behind automatically calculating IMT of carotid artery is to reduce the human effort and at the same time would benefit the patient by diagnosing the patient condition. The work that is proposed is analyzed by calculating various parameters in case of despeckling (filtering) as well as segmentation method. The performance parameters show that the proposed method performs better and at the same time reduces the manual effort