- Poster presentation
- Open Access
Self-navigated three-dimensional cardiac T2 mapping at 3T
© van Heeswijk et al; licensee BioMed Central Ltd. 2013
- Published: 30 January 2013
- Healthy Adult Subject
- Affine Registration
- Isotropic Spatial Resolution
- Radial Acquisition
- Proximal Left Circumflex
Cardiac T2 mapping using a variable T2 preparation module (T2Prep) has recently gained attention for its ability to quantify the extent of edema (Giri, JCMR 2009). Due to time constraints, the T2 maps are commonly acquired as one or several two-dimensional slices, while the underlying pathology has a three-dimensional (3D) structure. The next logical step would therefore be to exploit recent hardware and software advances to directly acquire 3D T2 maps. To this end, we tested the feasibility of using a self-navigated 3D radial acquisition with a variable T2Prep for 3D T2 mapping at 3T.
Approval was obtained from the institutional review board. A 3D self-navigated undersampled balanced steady-state free precession (bSSFP) sequence (TR/TE=2.6/1.33ms, matrix 1283, flip angle 70°) with a spiral phyllotaxis radial 3D trajectory (Piccini, MRM 2011) was implemented on a 3T clinical system (Skyra, Siemens AG). This self-navigated pulse sequence allows free breathing acquisitions with 100% scan efficiency, while ECG triggering every 2 heartbeats and TET2Prep=60/30/0ms allow for a total acquisition time of ~18min with an isotropic spatial resolution of (1.7mm)3. The datasets were registered using 3D affine registration (Studholme, Med Image Anal 1996). Through Bloch equation simulations, the heart-rate-dependent T1 -relaxation-related offset in the T2-fitting equation was ascertained. Subsequently, the validity and accuracy of the T2 fitting was tested in a phantom whose "true" T2 values were previously determined. The in vivo robustness of the T2 determination was then tested in 9 healthy adult subjects. Finally, the sequence was applied for the detection of edema in a 75-year-old male infarct patient after revascularization of his proximal left circumflex.
The proposed technique provides an easy and time-efficient way to obtain accurate isotropic T2 maps of the whole heart. Accurate T2 values were obtained in the phantom, while those in volunteers are consistent with previously reported values. The preliminary patient study demonstrated elevated T2 in the infarcted region as expected.
Foundation Emma Muschamp
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