scholarly journals Ανίχνευση υποκειμένου οργανικού υποστρώματος σε ασθενείς με κοιλιακές αρρυθμίες

2021 ◽  
Author(s):  
Χρυσοβαλάντου Νικολαΐδου
Keyword(s):  
Feature Tracking

Οι συνήθεις απεικονιστικές μεθόδοι αδυνατούν να αναγνώρισουν δομικές ανωμαλίες σε ένα σημαντικό ποσοστό ασθενών με ιδιοπαθείς κοιλιακές αρρυθμίες. Η μυοκαρδιακή παραμόρφωση έχει αναδειχθεί ως ανώτερος δείκτης της συστολικής απόδοσης σε σχέση με το κλάσμα εξώθησης. Σκοπός της παρούσας διατριβής ήταν η εκτίμηση της διαγνωστικής αξίας της Μαγνητικής Τομογραφίας Καρδιάς (ΜΤΚ), συμπεριλαμβανομένης της μυοκαρδιακής παραμόρφωσης με την τεχνική feature-tracking σε ασθενείς με συχνές κοιλιακές αρρυθμίες και φυσιολογικές δομικά καρδιές. Στη μελέτη συμπεριλήφθηκαν 72 ασθενείς (μέση ηλικία 46 ± 16 έτη, 53% γυναίκες) με συχνά πρώιμα κοιλιακά συμπλέγματα (ΠΚΣ ≥ 500/24ωρο) και/ή μη εμμένουσα κοιλιακή ταχυκαρδία, φυσιολογικό υπερηχοκαρδιογράφημα και αρνητική μελέτη για στεφανιαία νόσο, καθώς και 72 υγιείς εθελοντές. Η ΜΤΚ παρείχε επιπλέον διαγνωστική αξία στο 54,2% των ασθενών. Η συχνότερη διάγνωση ήταν η προηγούμενη μυοκαρδίτιδα (23,6%), ακολουθούμενη από μυοκαρδιοπάθεια προκαλούμενη από ΠΚΣ (20,8%), μη ισχαιμική μυοκαρδιοπάθεια (8,3%), και ισχαιμική καρδιακή νόσος (1,4%). Το αρσενικό φύλο, η μεγαλύτερη ηλικία και η προέλευση της κοιλιακής αρρυθμίας εκτός των χώρων εξόδου των κοιλιών ή αρρυθμίες με πολλαπλές μορφολογίες, αποτελούσαν ανεξάρτητους προγνωστικούς παράγοντες παθολογικών ευρημάτων στη ΜΤΚ. Σε σχέση με τους υγιείς εθελοντές, οι ασθενείς με κοιλιακές αρρυθμίες είχαν επηρεασμένη μέγιστη συνολική ακτινική παραμόρφωση (GRS) (28,88% [IQR: 25,87% έως 33,97%] έναντι 36,65% [IQR: 33,19% έως 40.,2%], p < 0,001) και μέγιστη συνολική κυκλοτερή παραμόρφωση (GCS) της αριστερής κοιλίας (-17,73% [IQR: -19,8% έως -16,33%] έναντι -20,66% [IQR: -21,72% έως -19,6%], p < 0,001). Οι ασθενείς με χαμηλότερο GRS (<29,91%) είχαν 5 φορές μεγαλύτερη πιθανότητα να πάσχουν από κοιλιακές αρρυθμίες. Συμπεραίνουμε ότι η ΜΤΚ αποκαλύπτει υποκείμενο οργανικό υπόστρωμα και επηρεασμένη μυοκαρδιακή παραμόρφωση σε έναν σημαντικό αριθμό ασθενών με ιδιοπαθείς κοιλιακές αρρυθμίες. Το αρσενικό φύλο, η μεγαλύτερη ηλικία και η προέλευση της κοιλιακής αρρυθμίας εκτός των χώρων εξόδου των κοιλιών, μπορεί να αποτελέσουν κλινικά κριτήρια για παραπομπή για ΜΤΚ.

Quantification of myocardial function using MRI feature tracking in children - Determination of normal values

2014 ◽  
Vol 62 (S 02) ◽  
Author(s):  
A. Helling ◽  
S. Buss ◽  
A. Foell ◽  
D. Robbers-Visser ◽  
W.A. Helbing ◽  
...  
Keyword(s):  
Feature Tracking ◽  
Myocardial Function ◽  
Normal Values

MRT-basierte Strain-Analyse mittels Feature Tracking bei Myokarditis

2015 ◽  
Vol 187 (S 01) ◽  
Author(s):  
B Baeßler ◽  
G Michels ◽  
M Hellmich ◽  
J Kröger ◽  
D Maintz ◽  
...  
Keyword(s):  
Feature Tracking

Myokardiale Strain-Analyse mittels Feature-Tracking in hochbeschleunigter kardialer real time MRT

2019 ◽  
Author(s):  
F Harder ◽  
H Haubenreisser ◽  
S Sudarski ◽  
D Overhoff ◽  
U Attenberger ◽  
...  
Keyword(s):  
Real Time ◽  
Feature Tracking

The Improvement of Torsion Assessed by Cardiovascular Magnetic Resonance Feature Tracking after Coronary Artery Bypass Grafting: A Sensitive Index of Cardiac Function

2017 ◽  
Vol 20 (1) ◽  
pp. 026 ◽  
Author(s):  
Nan Cheng ◽  
Liuquan Cheng ◽  
Rong Wang ◽  
Lin Zhang ◽  
Changqing Gao
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ejection Fraction ◽  
Cardiac Function ◽  
Feature Tracking ◽  
Artery Bypass ◽  
Left Ventricular ◽  
Rapid Acquisition ◽  
Left Ventricular Torsion ◽  
Ventricular Torsion

Objective: The aim of this study was to quantify left ventricular torsion by newly applied cardiovascular magnetic resonance feature tracking (CMR-FT), and to evaluate the clinical value of the ventricular torsion as a sensitive indicator of cardiac function by comparison of preoperative and postoperative torsion.Methods: A total of 54 volunteers and 36 patients with previous myocardial infarction (MI) and LV ejection fraction (EF) between 30%-50% were screened preoperatively or postoperatively by MRI. The patients’ short axis views of the whole heart were acquired, and all patients had a scar area >75% in at least one of the anterior or inferior segments. Their apical and basal rotation values were analyzed by feature tracking, and the correlation analysis was performed for the improvement of LV torsion and ejection fraction after CABG. The intra- and inter-observer reliabilities of torsion measured by CMR-FT were assessed.Results: In normal hearts, the apex rotated counterclockwise in the systolic period with the peak rotation as 10.2 ± 4.8°, and the base rotated clockwise as the peak value was 7.0 ± 3.3°. There was a timing hiatus between the apex and base untwisting, during which period the heart recoils and its suction sets the stage for the following rapid filling period. The postoperative torsion and rotation significantly improved compared with preoperative ones. However, the traditional indicator of cardiac function, ejection fraction, didn’t show significant improvement.Conclusion: Left ventricular torsion derived from CMR-FT, which does not require specialized CMR sequences, was sensitive to patients with low ejection fraction whose cardiac function significantly improved after CABG. The rapid acquisition of this measurement has potential for the assessment of cardiac function in clinical practice. 

Embedded Gold Markers for Improved TEM/STEM Tomography Reconstruction

2008 ◽  
Author(s):  
Jian-Shing Luo ◽  
Chia-Chi Huang ◽  
Jeremy D. Russell
Keyword(s):  
3D Reconstruction ◽  
Feature Tracking ◽  
Semiconductor Device ◽  
Electron Tomography ◽  
Tracking Process ◽  
Carbon Coated ◽  
Novel Method ◽  
Tomography Reconstruction ◽  
Tilt Series ◽  
20 Nm

Abstract Electron tomography includes four main steps: tomography data acquisition, image processing, 3D reconstruction, and visualization. After acquisition, tilt-series alignments are performed. Two methods are used to align the tilt-series: cross-correlation and feature tracking. Normally, about 10-20 nm of fiducial markers, such as gold beads, are deposited onto one side of 100 mesh carbon-coated grids during the feature-tracking process. This paper presents a novel method for preparing electron tomography samples with gold beads inside to improve the feature tracking process and quality of 3D reconstruction. Results show that the novel electron tomography sample preparation method improves image alignment, which is essential for successful tomography in many contemporary semiconductor device structures.

scholarly journals Myocardial deformation in patients with a single left ventricle using 2D cardiovascular magnetic resonance feature tracking: a case–control study

2021 ◽  
Author(s):  
Fabian Strodka ◽  
Jana Logoteta ◽  
Roman Schuwerk ◽  
Mona Salehi Ravesh ◽  
Dominik Daniel Gabbert ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Ventricle ◽  
Feature Tracking ◽  
Systolic Function ◽  
Radial Strain ◽  
Left Ventricular ◽  
Lv Function ◽  
Significant Difference ◽  
Lv Volumes

AbstractVentricular dysfunction is a well-known complication in single ventricle patients in Fontan circulation. As studies exclusively examining patients with a single left ventricle (SLV) are sparse, we assessed left ventricular (LV) function in SLV patients by using 2D-cardiovascular magnetic resonance (CMR) feature tracking (2D-CMR-FT) and 2D-speckle tracking echocardiography (2D-STE). 54 SLV patients (11.4, 3.1–38.1 years) and 35 age-matched controls (12.3, 6.3–25.8 years) were included. LV global longitudinal, circumferential and radial strain (GLS, GCS, GRS) and strain rate (GLSR, GCSR, GRSR) were measured using 2D-CMR-FT. LV volumes, ejection fraction (LVEF) and mass were determined from short axis images. 2D-STE was applied in patients to measure peak systolic GLS and GLSR. In a subgroup analysis, we compared double inlet left ventricle (DILV) with tricuspid atresia (TA) patients. The population consisted of 19 DILV patients, 24 TA patients and 11 patients with diverse diagnoses. 52 patients were in NYHA class I and 2 patients were in class II. Most SLV patients had a normal systolic function but median LVEF in patients was lower compared to controls (55.6% vs. 61.2%, p = 0.0001). 2D-CMR-FT demonstrated reduced GLS, GCS and GCSR values in patients compared to controls. LVEF correlated with GS values in patients (p < 0.05). There was no significant difference between GLS values from 2D-CMR-FT and 2D-STE in the patient group. LVEF, LV volumes, GS and GSR (from 2D-CMR-FT) were not significantly different between DILV and TA patients. Although most SLV patients had a preserved EF derived by CMR, our results suggest that, LV deformation and function may behave differently in SLV patients compared to healthy subjects.

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