Abstract Archives of the RSNA, 2012
True Real-Time Cardiac MRI with Radial K-Space Sampling in Free Breathing without ECG-synchronization—Improved Image Quality with Iterative Image Reconstruction
Scientific Formal (Paper) Presentations
Presented on November 26, 2012
Presented as part of SSC02: Cardiac (Anatomy and Function II)
Ralf W. Bauer MD, Presenter: Research Consultant, Siemens AG
Speakers Bureau, Siemens AG
Isabel Radtke BSC, Abstract Co-Author: Nothing to Disclose
Martin Uecker, Abstract Co-Author: Research collaboration, Siemens AG
Shuo Zhang MS, Abstract Co-Author: Research collaboration, Siemens AG
Kai Tobias Block, Abstract Co-Author: Employee, Siemens AG
Thomas G. Graf PhD, Abstract Co-Author: Employee, Siemens AG
Josef Matthias Kerl MD, Abstract Co-Author: Research Consultant, Siemens AG
Speakers Bureau, Siemens AG
Thomas Josef Vogl MD, PhD, Abstract Co-Author: Nothing to Disclose
Maya Christina Larson, Abstract Co-Author: Nothing to Disclose
Radial k-space sampling often suffers from artifacts and low signal when aiming at high temporal resolution. We investigated the role of iterative reconstruction concerning image quality and temporal resolution of a novel TrueFISP sequence based on radial k-space sampling (rTrueFISP) for real-time functional cardiac evaluation compared to standard balanced steady-state free precision (bSSFP).
12 healthy volunteers (mean age 27 y, mean heart rate 71±10 bpm) underwent 1.5 T cardiac MRI. Single-shot short axis views (8 mm slabs, 20% gap) were acquired with a) retrospectively ECG-gated segmented bSSFP in breath-hold and b) free breathing non-ECG-synchronized rTrueFISP with sliding-window (5 subframes) or iterative image (IR) reconstruction with a temporal resolution per single image of 36 fr/s. Left ventricular functional parameters (EDV, ESV, EF) were determined according to the Simpson’s rule with bSSFP representing the reference standard. Contrast-to-noise-ratio (CNR) of myocardium/blood pool was calculated. Subjective image quality was assessed by two radiologists (1=excellent, 6=non-diagnostic).
LV functional parameters showed strong correlation (r=0.97-98; p<0.001) between bSSFP and rTrueFISP with both different ways of image reconstruction (EF: 68±6% vs. 67±6% vs 66±6%). CNR (15.2 vs. 8.5 vs. 16.4) and overall subjective image quality (1.9±0.8 vs. 1.6±0.5) significantly improved with IR compared to sliding-window rTrueFISP and was comparable to bSSFP. Foremost, artifact burden was significantly reduced.
The implementation of iterative image reconstruction in real-time free-breathing non-ECG-gated rTrueFISP imaging significantly reduces artifacts and improves overall image quality, while the accuracy of LV functional analysis in comparison with the standard ECG-gated breath-hold cine bSSFP sequences was maintained.
With improved image quality real-time cardiac MRI with radial k-space sampling took an important step for the acceptance and robustness of this novel sequence for clinical use in actual patients.
True Real-Time Cardiac MRI with Radial K-Space Sampling in Free Breathing without ECG-synchronization—Improved Image Quality with Iterative Image Reconstruction. Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12026589.html