title: Four-dimensional (4D) flow of the whole heart and great vessels using real-time respiratory self-gating.
abstract: Four-dimensional (4D) flow imaging has been used to study flow patterns and pathophysiology, usually focused on specific thoracic vessels and cardiac chambers. Whole-heart 4D flow at high measurement accuracy covering the entire thoracic cardiovascular system would be desirable to simplify and improve hemodynamic assessment. This has been a challenge because compensation of respiratory motion is difficult to achieve, but it is paramount to limit artifacts and improve accuracy. In this work we propose a self-gating technique for respiratory motion-compensation integrated into a whole-heart 4D flow acquisition that overcomes these challenges. Flow components are measured in all three directions for each pixel over the complete cardiac cycle, and 1D volume projections are obtained at certain time intervals for respiratory gating in real time during the acquisition. The technique was tested in 15 volunteers, in which stroke volumes (SVs) in the great arteries showed excellent agreement with standard 2D phase-contrast (PC) scans. In contrast, nongated 4D flow with two averages had substantial disagreement with 2D flow. Applied to patients with congenital cardiac left-to-right shunting, the precision of flux data was highly beneficial. The methodology presented here has the potential to allow a complete study of flow pathophysiology of the thoracic cardiovascular system from a single free-breathing scan.
authors: Division of Imaging Sciences, British Heart Foundation (BHF) National Centre, Guy's and St Thomas' National Health Service (NHS) Foundation Trust, King's College London, London, UK. sergio.uribe_arancibia@kcl.ac.uk
authors: Sergio
authors: S
authors: Uribe
authors: Philipp
authors: P
authors: Beerbaum
authors: Thomas Sangild
authors: TS
authors: Sørensen
authors: Allan
authors: A
authors: Rasmusson
authors: Reza
authors: R
authors: Razavi
authors: Tobias
authors: T
authors: Schaeffter
mesh_terms: D000328:Adult; D000465:Algorithms; D003199:Computer Systems; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity