scholarly journals An Improved Level Set Algorithm Based on Prior Information for Left Ventricular MRI Segmentation

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 707
Author(s):  
Lei Xu ◽  
Yuhao Zhang ◽  
Haima Yang ◽  
Xuedian Zhang
Keyword(s):  
Level Set ◽  
Prior Information ◽  
Left Ventricular ◽  
Initial Contour ◽  
Curve Evolution ◽  
Segmentation Result ◽  
Mri Segmentation ◽  
Position Information ◽  
Original Algorithm ◽  
The Mean

This paper proposes a new level set algorithm for left ventricular segmentation based on prior information. First, the improved U-Net network is used for coarse segmentation to obtain pixel-level prior position information. Then, the segmentation result is used as the initial contour of level set for fine segmentation. In the process of curve evolution, based on the shape of the left ventricle, we improve the energy function of the level set and add shape constraints to solve the “burr” and “sag” problems during curve evolution. The proposed algorithm was successfully evaluated on the MICCAI 2009: the mean dice score of the epicardium and endocardium are 92.95% and 94.43%. It is proved that the improved level set algorithm obtains better segmentation results than the original algorithm.

scholarly journals An Integrated Strategy toward the Extraction of Contour and Region of Sonar Images

2020 ◽  
Vol 8 (8) ◽  
pp. 595
Author(s):  
Huipu Xu ◽  
Wenjie Lu ◽  
Meng Joo Er
Keyword(s):  
Level Set ◽  
Lattice Boltzmann ◽  
Initial Contour ◽  
Segmentation Result ◽  
Clustering Method ◽  
Region Segmentation ◽  
Sonar Images ◽  
Segmentation Task ◽  
Boltzmann Method ◽  
Improved Methods

In this paper, an integrated underwater sonar image extraction strategy, which combines two improved methods, namely the level set method (LSM) and the Lattice Boltzmann Method (LBM), is proposed. First, sonar images are processed by a clustering method and a connected domain analysis to generate the target minimum rectangle frame. Next, the segmentation task is decomposed into two subtasks, namely a coarse segmentation task to obtain the initial contour and a fine segmentation task after embedding the initial contour. Finally, the improved LSM is used to obtain the target contour, and the coarse contour of the segment is embedded into the LBM to obtain the region segmentation of the target in the sonar images. The main contributions of the paper are as follows: (1) The contours and regions of the sonar images are extracted simultaneously. (2) The original LBM method is enhanced to solve the level set iteration problem. (3) The region segmentation with the original image background is extracted, and a more intuitive region segmentation result than that of directly extracting the contour of the level set is achieved. Experimental results based on four evaluation indices of image segmentation show that our method is effective, accurate, and superior to other existing methods.

Improved Algorithm Based on Level Set Image Segmentation Methods

2014 ◽  
Vol 687-691 ◽  
pp. 4128-4131
Author(s):  
Hong Wei Han
Keyword(s):  
Image Segmentation ◽  
Level Set ◽  
Active Contour Model ◽  
Level Set Methods ◽  
Initial Contour ◽  
Segmentation Result ◽  
Level Set Function ◽  
Segmentation Methods ◽  
Set Function ◽  
Image Segmentation Algorithm

Image segmentation is one of the most fundamental and important areas in the field of image processing and computer vision. The traditional level set methods need initialize the level set function as a distance function. If the initial contour is selected inappropriate, we may not get the desired ideal segmentation result. In order to solve the problem of level set automation initial, we proposed a new image segmentation algorithm based on level set and marker extraction. First, we extract the internal mark as level set initial curve by using Extended-minima transform. And then, through using the local binary fitting active contour model, we evolve the labeled image to get the final segmentation result. The simulation results show that this method has low computing complexity than the traditional level set method requirements, and can effectively solve the initialization problem of level set.

Left Ventricular Dysfunction and Blood Glycohemoglobin Levels in Young Diabetics

1991 ◽  
Vol 30 (05) ◽  
pp. 183-188
Author(s):  
A. Aydrner ◽  
A. Oto ◽  
E. Oram ◽  
O. Gedik ◽  
C. F. Bekdik ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Left Ventricular Function ◽  
Ventricular Function ◽  
Left Ventricular ◽  
Diabetic Patients ◽  
Filling Fraction ◽  
Time To Peak ◽  
Significant Difference ◽  
The Mean ◽  
Hba1c Levels

Left ventricular function including regional wall motion (RWM) was evaluated by 99mTc first-pass and equilibrium gated blood pool ventriculography and glycohemoglobin (HbA1c) blood levels determined by a quantitative column technique in 25 young patients with insulin-dependent diabetes mellitus without clinical evidence of heart disease, and in healthy controls matched for age and sex. Phase analysis revealed abnormal RWM in 19 of 21 diabetic patients. The mean left ventricular global ejection fraction, the mean regional ejection fraction and the mean 1/3 filling fraction were lower and the time to peak ejection, the time to peak filling and the time to peak ejection /cardiac cycle were longer in diabetics than in controls. We found high HbA1c levels in all diabetics. There was no significant difference between patients with and without retinopathy and with and without peripheral neuropathy in terms of left ventricular function and HbA1c levels.

Direct Myocardial Implantation of Human Fetal Stem Cells in Heart Failure Patients: Long-term Results

2010 ◽  
Vol 13 (1) ◽  
pp. 31 ◽  
Author(s):  
Federico Benetti ◽  
Ernesto Pe�herrera ◽  
Teodoro Maldonado ◽  
Yan Duarte Vera ◽  
Valvanur Subramanian ◽  
...  
Keyword(s):  
Heart Failure ◽  
Stem Cells ◽  
Cardiac Function ◽  
Nyha Class ◽  
Left Ventricular ◽  
Long Term Results ◽  
Walk Test ◽  
The Mean ◽  
6 Minute Walk Test ◽  
Minute Walk

Background: End-stage heart failure (HF) is refractory to current standard medical therapy, and the number of donor hearts is insufficient to meet the demand for transplantation. Recent studies suggest autologous stem cell therapy may regenerate cardiomyocytes, stimulate neovascularization, and improve cardiac function and clinical status. Although human fetal-derived stem cells (HFDSCs) have been studied for the treatment of a variety of conditions, no clinical studies have been reported to date on their use in treating HF. We sought to determine the efficacy and safety of HFDSC treatment in HF patients.Methods and Results: Direct myocardial transplantation of HFDSCs by open-chest surgical procedure was performed in 10 patients with HF due to nonischemic, nonchagasic dilated cardiomyopathy. Before and after the procedure, and with no changes in their preoperative doses of medications (digoxin, furosemide, spironolactone, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, betablockers), patients were assessed for New York Heart Association (NYHA) class, performance in the exercise tolerance test (ETT), ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD) via transthoracic echocardiography, performance in the 6-minute walk test, and performance in the Minnesota congestive HF test. All 10 patients survived the operation. One patient had a stroke 3 days after the procedure, and although she later recovered, she was unable to perform the follow-up tests. Another male patient experienced pericardial effusion 3 weeks after the procedure. Although it resolved spontaneously, the patient abandoned his control tests and died 5 months after the procedure. An autopsy of the myocardium suggested that new young cells were present in the cardiomyocyte mix. At 40 months, the mean (SD) NYHA class decreased from 3.4 0.5 to 1.33 0.5 (P = .001); the mean EF increased 31%, from 26.6% 4% to 34.8% 7.2% (P = .005); and the mean ETT increased 291.3%, from 4.25 minutes to 16.63 minutes (128.9% increase in metabolic equivalents, from 2.46 to 5.63) (P < .0001); the mean LVEDD decreased 15%, from 6.85 0.6 cm to 5.80 0.58 cm (P < .001); mean performance in the 6-minute walk test increased by 43.2%, from 251 113.1 seconds to 360 0 seconds (P = .01); the mean distance increased 64.4%, from 284.4 144.9 m to 468.2 89.8 m (P = .004); and the mean result in the Minnesota test decreased from 71 27.3 to 6 5.9 (P < .001).Conclusion: Although these initial findings suggest direct myocardial implantation of HFDSCs is feasible and improves cardiac function in HF patients at 40 months, more clinical research is required to confirm these observations.

scholarly journals Does age at aortic coarctation repair have an impact on left ventricle size and function?

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
S Cardoso Torres ◽  
CX Resende ◽  
PG Diogo ◽  
P Araujo ◽  
RA Pinto ◽  
...  
Keyword(s):  
Aortic Coarctation ◽  
Surgical Repair ◽  
Myocardial Dysfunction ◽  
Global Longitudinal Strain ◽  
Negative Relationship ◽  
Late Complications ◽  
Left Ventricular ◽  
Funding Sources ◽  
The Mean ◽  
Clinical Records

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Adults with repaired aortic coarctation (CoA) require lifelong follow-up due to late complications, including left ventricular (LV) myocardial dysfunction. Age at the time of CoA repair is an important prognostic factor in these patients (pts). Purpose To evaluate LV size, ejection fraction (EF) and global longitudinal strain (GLS) values using 2D speckle tracking echocardiography (STE) in a population of adult pts with repaired CoA and to assess the relationship between these echocardiographic parameters and age at the time of CoA repair. Methods Retrospective analysis of adult pts with repaired CoA, followed in a Grown Up Congenital Heart Disease Centre. Pts with hemodynamically significant concomitant cardiac lesions were ruled out. Epidemiologic and clinical data were obtained from clinical records. Transthoracic echocardiograms were reviewed in order to assess GLS using 2DSTE (Echopac Software, GE). Results The study population consisted of 63 pts (61.9% male), with a mean age of 35.3 years at the time of the echocardiographic evaluation. The mean age at the time of the CoA repair was 117 months (95% CI 89.8-144.1 months). Surgical repair was performed in 46 pts (73%): resection with subclavian artery flap aortoplasty (n = 21); patch aortoplasty (n = 15) and head-to-head anastomosis (n = 10). In 10 pts there was no data regarding the type of surgical repair. Seven pts (11.1%) were submitted to percutaneous intervention (6 with aortic stent implantation and 1 with balloon aortic angioplasty). Mean LVEF was 63.4% (CI 95% 55.6 – 71.2%) and mean LV end-diastolic diameter (LVEDD) was 50mm (CI 95% 43-57mm). Mean GLS was - 17.3 (CI 95% 14.8- 19.8), which is inferior to the mean normal values reported for the software used. Age at the time of CoA repair had a statistically significant positive linear relationship with LVEDD (r= 0.282; p= 0.026) and a linear negative relationship with both GLS (r= -0,29; p= 0.022) and LVEF (r= -0.33; p= 0.05). Conclusion Older age at the time of CoA repair was associated with increased LVEDD and decreased GLS and LVEF. Also, GLS may be an important tool for the identification of subclinical LV dysfunction in adult pts with repaired CoA.

scholarly journals Accuracy, Labor-Time and Patient-Reported Outcomes with Partially versus Fully Digital Workflow for Flapless Guided Dental Implants Insertion—A Randomized Clinical Trial with One-Year Follow-Up

2021 ◽  
Vol 10 (5) ◽  
pp. 1102
Author(s):  
Corina Marilena Cristache ◽  
Mihai Burlibasa ◽  
Ioana Tudor ◽  
Eugenia Eftimie Totu ◽  
Fabrizio Di Francesco ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Randomized Clinical Trial ◽  
Dental Implants ◽  
Entry Point ◽  
Angular Deviation ◽  
Digital Workflow ◽  
Position Information ◽  
Patient Reported ◽  
The Mean ◽  
Edentulous Patients

(1) Background: Prosthetically-driven implant positioning is a prerequisite for long-term successful treatment. Transferring the planned implant position information to the clinical setting could be done using either static or dynamic guided techniques. The 3D model of the bone and surrounding structures is obtained via cone beam computed tomography (CBCT) and the patient’s oral condition can be acquired conventionally and then digitalized using a desktop scanner, partially digital workflow (PDW) or digitally with the aid of an intraoral scanner (FDW). The aim of the present randomized clinical trial (RCT) was to compare the accuracy of flapless dental implants insertion in partially edentulous patients with a static surgical template obtained through PDW and FDW. Patient outcome and time spent from data collection to template manufacturing were also compared. (2) Methods: 66 partially edentulous sites (at 49 patients) were randomly assigned to a PDW or FDW for guided implant insertion. Planned and placed implants position were compared by assessing four deviation parameters: 3D error at the entry point, 3D error at the apex, angular deviation, and vertical deviation at entry point. (3) Results: A total of 111 implants were inserted. No implant loss during osseointegration or mechanical and technical complications occurred during the first-year post-implants loading. The mean error at the entry point was 0.44 mm (FDW) and 0.85 (PDW), p ≤ 0.00; at implant apex, 1.03 (FDW) and 1.48 (PDW), p ≤ 0.00; the mean angular deviation, 2.12° (FDW) and 2.48° (PDW), p = 0.03 and the mean depth deviation, 0.45 mm (FDW) and 0.68 mm (PDW), p ≤ 0.00; (4) Conclusions: Despite the statistically significant differences between the groups, and in the limits of the present study, full digital workflow as well as partially digital workflow are predictable methods for accurate prosthetically driven guided implants insertion.

Coronary artery z score values in adolescent elite male soccer players

2020 ◽  
pp. 1-5
Author(s):  
Stephan Gerling ◽  
Tobias Pollinger ◽  
Markus Johann Dechant ◽  
Michael Melter ◽  
Werner Krutsch ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Arteries ◽  
High Intensity ◽  
Left Main Coronary Artery ◽  
Left Ventricular ◽  
Soccer Players ◽  
Z Score ◽  
Left Main ◽  
Luminal Diameter ◽  
The Mean

Abstract Background: With the increased training loads at very early ages in European elite youth soccer, there is an interest to analyse coronary artery remodelling due to high-intensity exercise. Design and methods: Prospective echocardiographic study in 259 adolescent elite male soccer players and 48 matched controls. Results: The mean age was 12.7 ± 0.63 years in soccer players and 12.6 ± 0.7 years in controls (p > 0.05). Soccer players had significant greater indexed left ventricular mass (93 ± 13 g/m2 versus 79 ± 12 g/m2, p = 0.001). Both coronary arteries origin could be identified in every participant. In soccer players, the mean diameter of the left main coronary artery was 3.67 mm (SD ± 0.59) and 2.61 mm (SD ± 0.48) for right main coronary artery. Controls showed smaller mean luminal diameter (left main coronary artery, p = 0.01; right main coronary artery, p = 0.025). In soccer players, a total of 91% (n = 196) and in controls a total of 94% (n = 45) showed left main coronary artery z scores within the normal range: −2.0 to 2.0. In right main coronary artery, a pattern of z score values distribution was comparable (soccer players 94%, n = 202 vs. controls 84%, n = 40). A subgroup of soccer players had supernormal z score values (>2.0 to 2.5) for left main coronary artery (9%, n = 19, p = 0.01) and right main coronary artery (6%, n = 10, p = 0.025), respectively. Conclusion: Elite soccer training in early adolescence may be a stimulus strong enough to develop increased coronary arteries diameters. In soccer players, a coronary artery z score >2.0–2.5 might reflect a physiologic response induced by multiannual high-intensity training.

Mechanical circulatory support with the Impella 5.0 and the Impella Left Direct pumps for postcardiotomy cardiogenic shock at La Pitié-Salpêtrière Hospital

2019 ◽  
Vol 57 (1) ◽  
pp. 183-188 ◽  
Author(s):  
Charles-Henri David ◽  
Astrid Quessard ◽  
Ciro Mastroianni ◽  
Guillaume Hekimian ◽  
Julien Amour ◽  
...  
Keyword(s):  
Cardiogenic Shock ◽  
Mechanical Circulatory Support ◽  
Heart Function ◽  
Left Ventricular ◽  
Survival Outcome ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
The Mean ◽  
Postcardiotomy Cardiogenic Shock

Abstract OBJECTIVES Postcardiotomy cardiogenic shock (PCCS) is associated with high mortality rates of 50–80%. Although veno-arterial extracorporeal membrane oxygenation has been used as mechanical circulatory support in patients with PCCS, it is associated with a high rate of complications and poor quality of life. The Impella 5.0 and Impella Left Direct (LD) (Impella 5.0/LD) are minimally invasive left ventricular assist devices that provide effective haemodynamic support resulting in left ventricular unloading and systemic perfusion. Our goal was to describe the outcome of patients with PCCS supported with the Impella 5.0/LD at La Pitié-Salpêtrière Hospital. METHODS We retrospectively reviewed consecutive patients supported with the Impella 5.0/LD for PCCS between December 2010 and June 2015. Survival outcome and in-hospital complications were assessed. RESULTS A total of 29 patients (63 ± 14 years, 17% women) with PCCS were supported with the Impella 5.0/LD. At baseline, 69% experienced chronic heart failure, 66% had dilated cardiomyopathy and 57% had valvular disease. The mean EuroSCORE II was 22 ± 17 and the ejection fraction was 28 ± 11%. Most of the patients underwent isolated valve surgery (45%) or isolated coronary artery bypass grafting (38%). The mean duration of Impella support was 9 ± 7 days. Weaning from the Impella was successful in 72.4%, and 58.6% survived to discharge. Recovery of native heart function was observed in 100% of discharged patients. Survival to 30 days and to 1 year from Impella implant was 58.6% and 51.7%, respectively. CONCLUSIONS The Impella 5.0 and the Impella LD represent an excellent treatment option for critically ill patients with PCCS and are associated with favourable survival outcome and native heart recovery.

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