Self-gated fetal cardiac MRI with tiny golden angle iGRASP: A feasibility study.
To develop and assess a technique for self-gated fetal cardiac cine magnetic resonance imaging (MRI) using tiny golden angle radial sampling combined with iGRASP (iterative Golden-angle RAdial Sparse Parallel) for accelerated acquisition based on parallel imaging and compressed sensing.



Fetal cardiac data were acquired from five volunteers in gestational week 29-37 at 1.5T using tiny golden angles for eddy currents reduction. The acquired multicoil radial projections were input to a principal component analysis-based compression stage. The cardiac self-gating (CSG) signal for cardiac gating was extracted from the acquired radial projections and the iGRASP reconstruction procedure was applied. In all acquisitions, a total of 4000 radial spokes were acquired within a breath-hold of less than 15 seconds using a balanced steady-state free precession pulse sequence. The images were qualitatively compared by two independent observers (on a scale of 1-4) to a single midventricular cine image from metric optimized gating (MOG) and real-time acquisitions.



For iGRASP and MOG images, good overall image quality (2.8 ± 0.4 and 2.6 ± 1.3, respectively, for observer 1; 3.6 ± 0.5 and 3.4 ± 0.9, respectively, for observer 2) and cardiac diagnostic quality (3.8 ± 0.4 and 3.4 ± 0.9, respectively, for observer 1; 3.6 ± 0.5 and 3.6 ± 0.9, respectively, for observer 2) were obtained, with visualized myocardial thickening over the cardiac cycle and well-defined myocardial borders to ventricular lumen and liver/lung tissue. For iGRASP, MOG, and real time, left ventricular lumen diameter (14.1 ± 2.2 mm, 14.2 ± 1.9 mm, 14.7 ± 1.1 mm, respectively) and wall thickness (2.7 ± 0.3 mm, 2.6 ± 0.3 mm, 3.0 ± 0.4, respectively) showed agreement and no statistically significant difference was found (all P > 0.05). Images with iGRASP tended to have higher overall image quality scores compared with MOG and particularly real-time images, albeit not statistically significant in this feasibility study (P > 0.99 and P = 0.12, respectively).



Fetal cardiac cine MRI can be performed with iGRASP using tiny golden angles and CSG. Comparison with other fetal cardiac cine MRI methods showed that the proposed method produces high-quality fetal cardiac reconstructions.



2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:207-217.
Laboratory of Computing, Medical Informatics and Biomedical-Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Greece.|Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden.
Kostas
K
Haris
Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden.|Department of Diagnostic Radiology, Skåne University Hospital, Lund University, Lund, Sweden.
Erik
E
Hedström
Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden.
Sebastian
S
Bidhult
Siemens Healthcare AB, Malmoe, Sweden.
Frederik
F
Testud
Laboratory of Computing, Medical Informatics and Biomedical-Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Greece.
Nicos
N
Maglaveras
Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden.
Einar
E
Heiberg
Department of Obstetrics and Gynecology, Skåne University Hospital,Lund University, Lund, Sweden.
Stefan R
SR
Hansson
Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden.
Håkan
H
Arheden
Laboratory of Computing, Medical Informatics and Biomedical-Imaging Technologies, School of Medicine, Aristotle University of Thessaloniki, Greece.|Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden.
Anthony H
0000-0002-3786-3817
AH
Aletras
D000328:Adult; D000465:Algorithms; D057791:Cardiac Imaging Techniques / Q000379:methods*; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D044962:Data Compression; D005240:Feasibility Studies; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
cardiac MRI; compressed sensing; fetal MRI; golden-angle radial sampling; image reconstruction; self-gated