Arterial switch procedure for D-transposition of the great arteries: quantitative midterm evaluation of hemodynamic changes with cine MR imaging and phase-shift velocity mapping-initial experience.
OBJECTIVE
To evaluate cine magnetic resonance (MR) imaging and phase-shift velocity mapping for assessment of the hemodynamic relevance of stenotic segments or specific hemodynamic changes in the great vessels after an arterial switch procedure for correction of D-transposition of the great arteries.


METHODS
Twenty consecutive patients (age range, 2-17 years) with an acoustic window that was insufficient for Doppler transthoracic echocardiography were included in the study. Flow and diameter measurements of the pulmonary arterial trunk and its primary branches were performed with phase-shift velocity mapping and cine MR imaging.


RESULTS
There were good correlations between pressure gradients in the pulmonary arteries estimated with MR imaging and those measured with Doppler echocardiography (r = 0.83, n = 15) and cardiac catheterization (r = 0.90, n = 13). Cine MR imaging revealed that the diameters of the right and left pulmonary arteries decreased with the expansion of the aorta during systole, which increased the peak velocity. This temporary stenosis was more severe in the right than in the left pulmonary artery and was accompanied by a significantly (P <.05) lower volume flow in the right artery.


CONCLUSIONS
The anatomic situation after arterial switch repair tended to produce temporary stenoses in the primary pulmonary arterial branches, with significant changes in hemodynamics. These changes may affect the long-term outcome and go undetected with other imaging modalities.
Gutberlet
M
M
Department of Radiology, Charité, Campus Virchow-Klinikum, Medizinische Fakultät der Humboldt-Universität, Augustenburger Platz 1, 13353 Berlin, Germany. matthias.gutberlet@charite.de
Boeckel
T
T
Hosten
N
N
Vogel
M
M
Kühne
T
T
Oellinger
H
H
Ehrenstein
T
T
Venz
S
S
Hetzer
R
R
Bein
G
G
Felix
R
R
D000293:Adolescent; D001011:Aorta / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D011183:Postoperative Complications / Q000503:physiopathology; D011651:Pulmonary Artery / Q000503:physiopathology / Q000601:surgery*; D011665:Pulmonary Valve Insufficiency / Q000503:physiopathology; D011666:Pulmonary Valve Stenosis / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology; D013599:Systole; D014188:Transposition of Great Vessels / Q000503:physiopathology / Q000601:surgery*