Evaluation eines Echtzeit-Verfahrens in der kardialen Magnetresonanztomographie bei Patienten mit Herzrhytmusstörungen am Beispiel von Vorhofflimmern
Real-time-MRI and cardiac arrhythmia - evaluation of a new real-time-reconstruction in patients with atrial fibrillation
by Eckhart Thassilo von Loesch
Date of Examination:2017-03-09
Date of issue:2017-03-06
Advisor:Prof. Dr. Christina Unterberg-Buchwald
Referee:Prof. Dr. Christina Unterberg-Buchwald
Referee:Prof. Dr. Matthias Sigler
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Abstract
English
Cardiac MRI is regarded as gold-standard for analysis of left ventricular function. Commonly used CINE-SSFP is based on an interpolation of image data, which are acquired from several heart beats. This method is well established for patients in sinus-rhythm. In patients with cardiac arrhythmia it struggles because correlation of acquired data to the right cardiac phase is impeded. A new real-time-MRI-method with a temporal resolution of 40 ms (Real-Time-SSFP) is able to acquire images of cardiac movement consecutively. Image data from 30 patients with atrial fibrillation (AF) during MRI-scan were gained with both CINE-SSFP and Real-Time-SSFP. Additionally each patient obtained transthoracic echocardiography. Image quality of CINE-and Real-Time-MRI-images was scored by two independent observers on a scale from 0 (no diagnostic quality) to 4 (optimal diagnostic quality). To aquire data for cardiac function, images were evaluated with QMass MR (7.4.14.0 – real-time prototype, Medis medical imaging systems bv, Leiden, the Netherlands). The results were used for a comparison between CINE- and Real-Time-MRI. Additionaly both methods were compared with data acquired from echocardiography. Furthermore real-time data offered the possibility to perform a two-dimensional beat-to-beat-analysis in four-chamber-view and to calculate bandwith of ejection fraction. The quality-analysis gave significantly better results for real-time-SSFP than for CINE-SSFP. Due to reduced image-quality more than 10% of CINE-SSFP-images were not congenial for functional analysis. Comparison of functional parameters showed only slight differences between both MRI-methods, although Real-Time-MRI demonstrated a tendency to measure lower values. Real-Time-SSFP differed sligltly lower from echocardiography then CINE-SSFP. This survey showed that Real-Time-SSFP offers the possibility to get images with high diagnostic quality from patients with AF. The new method was also superior for functional analysis. The next task is to enhance segmentation software so that it can be easier used in clinical practice. For three-dimensional real-time-volumetry three dimensional data-acquisition is necessary – one of the biggest challenges in MRI-research. Further applications for Real-Time-MRI in patients with arrhythmia now can be evaluated.
Keywords: mri; arrhythmia; real-time-mri; atrial fibrillation; CINE; CINE-SSFP; SSFP; cardiac function; quality analysis
Schlagwörter: MRT; Real-Time-MRT; Echtzeit-MRT; Herzrhythmusstörungen; Vorhofflimmern; CINE-SSFP; SSFP; bSSFP; Qualitätsanalyse; Herzfunktion; Lotz