Outcome of degenerative nonprolapse mitral regurgitation using the average pixel intensity method

2020 ◽  
Vol 37 (9) ◽  
pp. 1329-1335
Author(s):  
Victor Kamoen ◽  
Milad El Haddad ◽  
Tine De Backer ◽  
Marc De Buyzere ◽  
Frank Timmermans
Keyword(s):  
Mitral Regurgitation ◽  
Pixel Intensity ◽  
Average Pixel Intensity

Grading of mitral regurgitation in mitral valve prolapse using the average pixel intensity method

2018 ◽  
Vol 258 ◽  
pp. 305-312 ◽  
Author(s):  
Victor Kamoen ◽  
Milad El Haddad ◽  
Marc De Buyzere ◽  
Tine De Backer ◽  
Frank Timmermans
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Prolapse ◽  
Pixel Intensity ◽  
Average Pixel Intensity

Average pixel intensity method for prediction of outcome in secondary mitral regurgitation

Heart ◽  
2020 ◽  
Vol 106 (12) ◽  
pp. 904-909 ◽  
Author(s):  
Victor Kamoen ◽  
Marc De Buyzere ◽  
Milad El Haddad ◽  
Tine L M de Backer ◽  
Frank Timmermans
Keyword(s):  
Heart Failure ◽  
Clinical Outcome ◽  
Mitral Regurgitation ◽  
Continuous Wave ◽  
Independent Predictor ◽  
Multivariable Analysis ◽  
Systolic Heart Failure ◽  
Pixel Intensity ◽  
Secondary Mitral Regurgitation ◽  
Average Pixel Intensity

BackgroundEchocardiographic grading of secondary mitral regurgitation (SMR) severity is challenging and involves multiple guideline-recommended parameters. We previously introduced the average pixel intensity (API) method for grading SMR. In this study, the clinical outcome in SMR based on the API method for grading MR was compared with conventional grading methods.Methods231 patients with systolic heart failure and reduced ejection fraction (ischaemic/non-ischaemic) and SMR were prospectively enrolled. MR was graded using all guideline-recommended parameters and the API method, which is based on the pixel intensity of the continuous wave Doppler signal. The primary outcome was MACE (major adverse cardiac event).ResultsThe API method was applicable in 98% of patients with SMR (n=227). During a median follow-up of 24 months, 98 patients (43%) had a MACE (cardiovascular mortality (n=50, 22%), heart failure hospitalisation (n=44, 19%), mitral valve surgery (n=11, 5%), percutaneous mitral intervention (n=12, 5%), heart transplantation (n=5, 2%)). On log-rank test, the API method was highly significant in predicting clinical outcome. On multivariable Cox proportional hazard analysis, SMR grading with the API method was an independent predictor of clinical outcome (along with NYHA class and right ventricular systolic pressure; p<0.001), increasing the event risk by 9% per 10 au API rise (p=0.001). In the same multivariable analysis, proximal isovelocity surface area (PISA)-effective regurgitant orifice area or PISA-regurgitant volume were not independent predictors of events (p=0.18 and 0.26, respectively).ConclusionSMR grading with the API method is an independent predictor of clinical outcome and provides prognostic information in addition to clinical and other echocardiographic variables.

scholarly journals P1554 Assessment of functional mitral regurgitation with leg lift and exercise echocardiography using the average pixel intensity method

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
V Kamoen ◽  
M El Haddad ◽  
T De Backer ◽  
F Timmermans
Keyword(s):  
Mitral Regurgitation ◽  
Continuous Wave ◽  
Color Doppler ◽  
Significant Rise ◽  
Added Value ◽  
Functional Mitral Regurgitation ◽  
Exercise Echocardiography ◽  
Pixel Intensity ◽  
Vena Contracta ◽  
Average Pixel Intensity

Abstract Background Dynamic changes in functional mitral regurgitation (FMR) during exercise echocardiography were shown to be of prognostic value. However grading of FMR is challenging, especially during exercise echocardiography and therefore questioning its applicability in clinical practice. We recently introduced and validated the Average Pixel Intensity (API) for grading MR based on the pixel intensity of the continuous wave Doppler signal. In the current study we investigate the use of the API method using leg lift and exercise echocardiography in FMR. Methods We prospectively included 50 heart failure patients (mean ejection fraction 36%) in sinus rhythm with different grades of pure, FMR. After assessment of FMR severity at rest, the same acquisitions were repeated during leg lift and exercise echocardiography. FMR was assessed using the API method, color Doppler and quantitative grading methods (proximal isovelocity surface area (PISA) and vena contracta width (VCW)). Results The API method could be performed in all patients (100%) with leg lift (n = 50) and in 94% of the patients undergoing exercise echocardiography (n = 44), which was more than PISA and VCW (p &lt; 0.001). During leg lift, there was a small but significant increase on visual color Doppler grading (grade 1.93 to 2.11 (p = 0.004); increase of FMR in 35% of patients, and no difference in 65%). For API, we found the same significant increase (93 to 101 au), however, API values showed increase of MR in 62% and decrease of FMR in 20%. During exercise echocardiography, we found no differences in color Doppler grade and API in the overall cohort (p 0.252 and p 0.832, respectively), despite 62% of patients showing some degree of increase in API during leg lift. On multivariate analysis, no specific echo parameter could be identified as independent predictor of API increase. Conclusions The novel API method is highly feasible for assessing dynamic FMR and may be of added value for in this setting, allowing the detection of even small increments of FMR severity. In the current study, we found only mild increases of FMR during exercise echocardiography. Leg lift testing however proved to be a simple and quick loading approach that induced a significant rise in FMR compared to exercise echocardiography. The prognostic relevance of the findings during leg lift remains to be determined.

The Average Pixel Intensity Method and Outcome of Mitral Regurgitation in Mitral Valve Prolapse

2020 ◽  
Vol 33 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Victor Kamoen ◽  
Milad El Haddad ◽  
Tine De Backer ◽  
Marc De Buyzere ◽  
Frank Timmermans
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Prolapse ◽  
Pixel Intensity ◽  
Average Pixel Intensity

Insights into functional mitral regurgitation using the average pixel intensity method

2018 ◽  
Vol 35 (5) ◽  
pp. 761-769 ◽  
Author(s):  
Victor Kamoen ◽  
Milad El Haddad ◽  
Tine De Backer ◽  
Marc De Buyzere ◽  
Frank Timmermans
Keyword(s):  
Mitral Regurgitation ◽  
Functional Mitral Regurgitation ◽  
Pixel Intensity ◽  
Average Pixel Intensity

A Comparison of Near-Infrared Imaging and Computerized Tomography Scan for Detecting Maxillary Sinusitis

2021 ◽  
pp. 000348942110606
Author(s):  
Mehdi Abouzari ◽  
Brooke Sarna ◽  
Joon You ◽  
Adwight Risbud ◽  
Kotaro Tsutsumi ◽  
...  
Keyword(s):  
Maxillary Sinus ◽  
Computerized Tomography ◽  
Sensitivity And Specificity ◽  
Near Infrared ◽  
Maxillary Sinusitis ◽  
Tertiary Care ◽  
Pixel Intensity ◽  
Sinus Disease ◽  
Nir Imaging ◽  
Average Pixel Intensity

Objective: To investigate the use of near-infrared (NIR) imaging as a tool for outpatient clinicians to quickly and accurately assess for maxillary sinusitis and to characterize its accuracy compared to computerized tomography (CT) scan. Methods: In a prospective investigational study, NIR and CT images from 65 patients who presented to a tertiary care rhinology clinic were compared to determine the sensitivity and specificity of NIR as an imaging modality. Results: The sensitivity and specificity of NIR imaging in distinguishing normal versus maxillary sinus disease was found to be 90% and 84%, normal versus mild maxillary sinus disease to be 76% and 91%, and mild versus severe maxillary sinus disease to be 96% and 81%, respectively. The average pixel intensity was also calculated and compared to the modified Lund-Mackay scores from CT scans to assess the ability of NIR imaging to stratify the severity of maxillary sinus disease. Average pixel intensity over a region of interest was significantly different ( P < .001) between normal, mild, and severe disease, as well as when comparing normal versus mild ( P < .001, 95% CI 42.22-105.39), normal versus severe ( P < .001, 95% CI 119.43-174.14), and mild versus severe ( P < .001, 95% CI 41.39-104.56) maxillary sinus disease. Conclusion: Based on this data, NIR shows promise as a tool for identifying patients with potential maxillary sinus disease as well as providing information on severity of disease that may guide administration of appropriate treatments.

An innovative model to quantify corneal transparency in donor corneal buttons

2017 ◽  
Vol 6 (6) ◽  
pp. 202-205
Author(s):  
Jeyanth Rose ◽  
Syrpailyne Wankhar ◽  
Aarwin Joshua ◽  
Sanita Korah ◽  
Thomas Kuriakose
Keyword(s):  
Anterior Chamber ◽  
Digital Camera ◽  
Laser Source ◽  
Corneal Transplant ◽  
Human Cornea ◽  
Proof Of Concept ◽  
Pixel Intensity ◽  
Corneal Transparency ◽  
Average Pixel Intensity ◽  
Corneal Button

Assessment of corneal transparency in donor corneal buttons has only been performed qualitatively. The quantification of corneal transparency has implications with respect to clinical suitability of the donor cornea and research involving corneal transparency as an outcome measure. In this study an artificial anterior chamber was modified to create a central transparent passage. This was made possible by replacing the base of the chamber with Perspex and a water  tight seal. An inlet and outlet tube was a ached to the sides of chamber. This was done to maintain a standardized pressure within the chamber when connected to an IV bo le. A corneal button rejected for corneal transplant was placed on the artificial anterior chamber and the chamber was  filled with normal saline. A digital camera and a laser source were placed on either side of the chamber at predetermined intervals. Alignment was achieved so that the laser light passed through the center of the cornea. The image of the laser spot was acquired and subjected to image analysis. To test this proof of concept, a human cornea rejected for human transplant was injected with intrastromal saline to create corneal haze. Pre and Post injection images were analyzed. The average pixel intensity that was calculated was found to be 111 pre-saline injury and 17.2 post-saline injection. Pre and Post-saline measurement showed a marked difference in average pixel intensity. This simple inexpensive setup and ease of analysis are advantages of this method of quantification.

Impaired Intracellular Ca2+Dynamics in Live Cardiomyocytes Revealed by Rapid Line Scan Confocal Microscopy

2005 ◽  
Vol 11 (3) ◽  
pp. 235-243 ◽  
Author(s):  
David M. Plank ◽  
Mark A. Sussman
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Intensity ◽  
Linear Regression Analysis ◽  
Data Interpretation ◽  
Live Cells ◽  
Correction Factors ◽  
Pixel Intensity ◽  
Scanning Confocal Microscopy ◽  
Intracellular Ca ◽  
Average Pixel Intensity

Altered intracellular Ca2+dynamics are characteristically observed in cardiomyocytes from failing hearts. Studies of Ca2+handling in myocytes predominantly use Fluo-3 AM, a visible light excitable Ca2+chelating fluorescent dye in conjunction with rapid line-scanning confocal microscopy. However, Fluo-3 AM does not allow for traditional ratiometric determination of intracellular Ca2+concentration and has required the use of mathematic correction factors with values obtained from separate procedures to convert Fluo-3 AM fluorescence to appropriate Ca2+concentrations. This study describes methodology to directly measure intracellular Ca2+levels using inactivated, Fluo-3-AM-loaded cardiomyocytes equilibrated with Ca2+concentration standards. Titration of Ca2+concentration exhibits a linear relationship to increasing Fluo-3 AM fluorescence intensity. Images obtained from individual myocyte confocal scans were recorded, average pixel intensity values were calculated, and a plot is generated relating the average pixel intensity to known Ca2+concentrations. These standard plots can be used to convert transient Ca2+fluorescence obtained with experimental cells to Ca2+concentrations by linear regression analysis. Standards are determined on the same microscope used for acquisition of unknown Ca2+concentrations, simplifying data interpretation and assuring accuracy of conversion values. This procedure eliminates additional equipment, ratiometric imaging, and mathematic correction factors and should be useful to investigators requiring a straightforward method for measuring Ca2+concentrations in live cells using Ca2+-chelating dyes exhibiting variable fluorescence intensity.

P3372Prediction of outcome in functional mitral regurgitation using the average pixel intensity method

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
V Kamoen ◽  
M El Haddad ◽  
M De Buyzere ◽  
T De Backer ◽  
F Timmermans
Keyword(s):  
Heart Failure ◽  
Multivariate Analysis ◽  
Mitral Valve ◽  
Mitral Valve Surgery ◽  
Valve Surgery ◽  
Functional Mitral Regurgitation ◽  
Heart Failure Hospitalization ◽  
Pixel Intensity ◽  
Clinical Events ◽  
Average Pixel Intensity

Abstract Background Functional mitral regurgitation (FMR) is a frequent finding in patients with systolic heart failure. However, the echocardiographic grading of MR is challenging and different severity cut-offs are recommended by international guidelines. We developed and validated a novel echocardiographic parameter to grade MR, the average pixel intensity (API) method, based on pixel intensity analysis of the continuous wave Doppler signal. Purpose In this study, we assessed the long-term predictive value of the API method on clinical endpoints in FMR. Methods Transthoracic echocardiography was performed in consecutive heart failure patients with reduced EF (HF-REF) (n=221). MR was assessed using the API method, vena contracta width (VCW), effective regurgitant orifice area (PISA-EROA) and regurgitant volume (PISA-RV). The primary clinical events were major adverse cardiac events (MACE: cardiovascular mortality, mitral valve surgery, percutaneous mitral intervention or heart failure hospitalization). Results The API method was feasible in 97% of all FMR patients, which was significantly higher than parameters such as VCW, PISA-EROA and PISA-RV. 84 patients (37%) had one or more clinical events during the follow-up period (cardiovascular mortality (20%), mitral valve surgery (5%), percutaneous mitral intervention (5%), heart failure hospitalization (16%) or heart transplantation (2%)). Based on ROC curves, an API cut-off of 121 au was defined as “severe” MVP-MR with an overall better sensitivity and specificity than current guideline-recommended parameters. On multivariate analysis, MR graded with API was independently predictive for clinical events, whereas PISA-based methods were not independent. In addition, pulmonary pressures and NYHA class were powerful independent predictors of clinical outcome in FMR on multivariate analysis. Conclusions The API method better predicts clinical events and outcome in FMR compared to established grading methods. Therefore, the API method may be considered for grading FMR severity in clinical practice.

scholarly journals THU0540 A PHASE 2B STUDY OF INTRAVENOUSLY (IV) ADMINISTERED TC 99M TILMANOCEPT TO DETERMINE DIFFERENTIAL UPTAKE, REPRODUCIBILITY OVER TIME AND IMAGE STABILITY IN HEALTHY SUBJECTS AND IN PATIENTS WITH RHEUMATOID ARTHRITIS (RA) ON STABLE TREATMENT

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 509.2-510
Author(s):  
A. Hussein ◽  
D. Ralph ◽  
B. Potter ◽  
B. Abbruzzese ◽  
R. Hershey ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Joint Disease ◽  
Current Phase ◽  
Specific Reference ◽  
Activated Macrophages ◽  
Planar Imaging ◽  
Pixel Intensity ◽  
Cut Points ◽  
Over Time ◽  
Average Pixel Intensity

Background:At present, there are no reliable noninvasive means to directly monitor disease activity in RA patients. Activated macrophages are a critical component of the inflammatory etiology of RA due to their role in prolonged RA joint inflammation and destruction through the release of pro-inflammatory cytokines and chemokines. Tc 99m tilmanocept is a radiopharmaceutical imaging agent that binds with high affinity to the macrophage mannose receptor CD206 that resides on activated macrophages. Previous clinical trials demonstrated safety and tolerability of Tc 99m tilmanocept, as well as a determination of optimal clinical dose and timeframe for RA imaging.Objectives:The current phase 2b study aims to evaluate reproducibility and stability of imaging and will assess quantitative Tc 99m tilmanocept uptake cut points that reliably enable discrimination between joints of healthy people and RA patients.Methods:The analysis cohort contained 18 healthy controls (HC) clinically free of inflammatory joint disease and 12 subjects with clinically diagnosed RA who are on stable anti-inflammatory and/or anti-rheumatic therapy. Each subject received a 150-mcg dose of tilmanocept radiolabeled with 10 mCi of Tc 99m in a 3mL IV injection. Injection was followed by planar imaging at 60 and 180 minutes for both HC and RA subjects on study Day 0 and repeated in RA subjects on Day 8. Images were quantitatively assessed to detect localization within synovial spaces of bilateral hands and wrists by determining average pixel intensity in each region of interest relative to average pixel intensity in a joint-specific reference region.Results:Data obtained from the interim analysis support the hypothesis that Tc 99m tilmanocept imaging can provide robust quantitative imaging in HC and RA subjects. Repeat images within and between days demonstrate root mean squared differences that are approximately 10% or less of the observed localization of Tc 99m tilmanocept. Qualitatively, images of HC indicated no disease-related site-specific localization, whereas localization is present in RA subjects at levels expected given the difference in macrophage number and density in different pathotypes of RA. Notably, images from patients with active RA exhibit the same localization patterns on images taken in a test-retest fashion on the same day as well as in subjects with images acquired on Day 0 and Day 8 (see Figure 1). These results show low imaging readout variability, enabling reliable quantification of joints with RA-involved macrophage-mediated inflammation. Analysis of the HC and RA images was used to determine initial quantitative “cut-points” to differentiate between joints with and without the inflammation typically seen in RA.Figure 1.Tilmanocept consistently localizes in areas of macrophage-driven inflammation, demonstrating low variability. RA patients exhibit reproducible localization over a 1-week period. Typical of healthy subjects, no evidence of inflammation-related Tc 99m tilmanocept uptake was observed in the healthy control. Images on the right show same patient imaged on 2 different days.Conclusion:Tc 99m tilmanocept imaging of the joints in healthy subjects as well as in patients with active RA under stable treatment is reproducible and stable over time. The results confirmed that the signal in joints of healthy subjects and RA patients can be quantified and used to establish cut points to distinguish inflamed and non-inflamed joints on a joint-by-joint basis. These results provide the foundation for a noninvasive, objective method to monitor activity in macrophage-driven inflammation in joints of patients with RA.Disclosure of Interests:Ayah Hussein Employee of: Currently employed by Navidea Biopharmaceuticals, David Ralph Consultant of: Previous consultant for Navidea Biopharmaceuticals, Employee of: Currently employed by Navidea Biopharmaceuticals, Beth Potter Employee of: Currently employed by Navidea Biopharmaceuticals, Bonnie Abbruzzese Employee of: Currently employed by Navidea Biopharmaceuticals, Rachael Hershey Employee of: Currently employed by Navidea Biopharmaceuticals, Katherine Repp Employee of: Previously employed by Navidea Biopharmaceuticals, Haya Shakhtra Employee of: Currently employed by Navidea Biopharmaceuticals, Mehak Goel Employee of: Currently employed by Navidea Biopharmaceuticals, Madison Palmer Employee of: Currently employed by Navidea Biopharmaceuticals, Allison Kissling Employee of: Previously employed by Navidea Biopharmaceuticals, Carley Hartings Employee of: Previously employed by Navidea Biopharmaceuticals, Michael Blue Employee of: Currently employed by Navidea Biopharmaceuticals, Michael Rosol Employee of: Currently employed by Navidea Biopharmaceuticals

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