Quantitative Assessment of Left Ventricular Function with Interactive Real-Time Spiral and Radial MR Imaging

Abstract

An interactive real-time spiral gradient-echo and an interactive real-time radial steady-state free precession sequence were investigated for the quantitative assessment of left ventricular function. Data were acquired in 18 patients without electrocardiographic triggering and breath holding. With the interactive real-time spiral gradient-echo sequence, significant underestimation of endocardial and epicardial volumes was demonstrated; with the interactive real-time radial steady-state free precession sequence, excellent agreement was shown with standard cardiac-triggered segmented k-space breath-hold steady-state free precession MR imaging. Interactive real-time radial steady-state free precession imaging allows accurate quantitative assessment of left ventricular volumes.

Assessment of left ventricular function by breath‐hold cine MR imaging: Comparison of different steady‐state free precession sequences

“…Thus, the observed EDV differences are not exaggerated, but rather attenuated by the poorer spatial resolution in sequence protocol C. k-space sampling may play a role, too. Spuentrup et al (27) showed a good agreement for radial interactive real-time SSFP sequences, whereas spiral interactive real-time cine acquisitions significantly underestimated EDV, ESV, and SV. The implementation of parallel acquisition techniques in sequence 1 appears to be a promising alternative to reduce acquisition time for cine MR ventriculometry instead of using the shared phases approach.…”

“…Real-time cine frames can also be acquired during free breathing and without ECG-gating. This is a major advantage enabling cardiac MR imaging examinations in patients with arrhythmia or in patients who are unable to hold their breath (23,27,28). The time savings of the real-time technique are tremendous as only one breath-hold period is needed to cover the entire LV compared to about 12 minutes with the conventional single-slice approach (29).…”

MR imaging of thrombi using EP-2104R, a fibrin-specific contrast agent: initial results in patients

“…As atrial clot formation is commonly associated with atrial fibrillation, further sequence modifications may be required to obtain sufficient image quality in all cases. One solution may include real-time MR or other k-space sampling strategies (such as radial acquisitions) as these are less sensitive to motion artifacts [56][57][58][59]. Recently, several fibrin-specific contrast agents have been developed.…”

Cardiac Function

“…The beginning of this century coincided with the reintroduction and revival of the balanced steady-state free-precession GE sequence, which rapidly became the preferred bright-blood sequence for dynamic cardiac imaging (cine MRI) (Barkhausen et al 2001;Carr et al 2001;Thiele et al 2001;Plein et al 2001;Moon et al 2002;Lee et al 2002;Fieno et al 2002;Alfakih et al 2003a;Hori et al 2003;Spuentrup et al 2003). Use of this sequence, introduced in the early 1980s, was hampered for a long time because of issues such as main field nonuniformity, eddy currents, and inhomogeneous magnetic susceptibility, which have been solved with the newest-generation scanners.…”

“…This has urged several groups to develop clinically useful ultrafast and real-time sequences with an acceptable temporal resolution (below 50 ms) and in-plane spatial resolution (below 2.5 mm) (Kramer et al 2008). In addition to use of techniques such as view or echo sharing and parallel imaging, a substantial reduction in measurement time can be achieved by developing novel strategies to fill the k-space (e.g., partial k-space filling, radial or spiral k-space filling), and by exploiting correlations in k-space and time (k-t) such as k-t BLAST and k-t SENSE techniques (see ''Cardiac MR Physics''; Setser et al 2000;Nagel et al 2000;Kaji et al 2001;Barkhausen et al 2002;Lee et al 2002;Spuentrup et al 2003;Hori et al 2003;Kühl et al 2004;Taylor et al 2005;Jahnke et al 2006Jahnke et al , 2007Muthurangu et al 2008;Lurz et al 2009). …”