Phase-contrast MR assessment of pulmonary venous blood flow in children with surgically repaired pulmonary veins.
BACKGROUND
Pulmonary venous (PV) obstruction may complicate surgical repair of PV abnormalities. By combining phase-contrast cine (PC) imaging and contrast-enhanced angiography, magnetic resonance (MR) imaging can provide physiological information complementing anatomical diagnosis. OBJECTIVES. To compare the PV flow pattern observed after surgical repair of PV abnormalities with normal PV flow pattern and to investigate the changes occurring in the presence of PV stenosis by using PC MR in children.


METHODS
By using PC MR, PV flow was evaluated in 14 patients (3 months-14 years) who underwent surgical repair for PV abnormalities. Eleven children (8-18 years) were studied as normal controls. Peak flow velocities and patterns were compared among three groups: normal veins ( n=23), surgically repaired veins without ( n=44) and with stenosis ( n=10).


RESULTS
Normal and unobstructed pulmonary veins after surgery showed a biphasic or triphasic flow pattern with one or two systolic peaks and a diastolic peak. Unobstructed surgically repaired veins showed decreased peak systolic velocity ( P =0.001) and an increased peak diastolic velocity ( P=0.005) when compared to normal values. Obstructed veins showed decreased systolic and diastolic velocities when measured upstream from the stenosis.


CONCLUSIONS
PC MR shows different flow patterns among normal, surgically repaired pulmonary veins with and without stenosis.
Valsangiacomo
Emanuela R
ER
Department of Diagnostic Imaging, Division of Cardiac Imaging, The Hospital for Sick Children, The University of Toronto Faculty of Medicine, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8.
Barrea
Catherine
C
Macgowan
Christopher K
CK
Smallhorn
Jeffrey F
JF
Coles
John G
JG
Yoo
Shi-Joon
SJ
D000293:Adolescent; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic / Q000503:physiopathology; D006801:Humans; D007223:Infant; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D011183:Postoperative Complications / Q000503:physiopathology*; D011652:Pulmonary Circulation; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*