Three-dimensional imaging of pulmonary veins by a novel steady-state free-precession magnetic resonance angiography technique without the use of intravenous contrast agent: initial experience.
OBJECTIVE
To evaluate the feasibility of 3-dimensional (3D) steady-state free-precession (SSFP) magnetic resonance angiography (MRA) using nonselective radiofrequency excitation for imaging of pulmonary veins (PVs) without intravenous gadolinium chelate and to correlate the results with conventional contrast-enhanced MRA (CE-MRA).


METHODS
Forty consecutive patients with history of atrial fibrillation underwent free-breathing respiratory navigator-gated electrocardiogram-triggered SSFP MRA without contrast administration and conventional high-resolution 3D CE-MRA of the thorax at 1.5 T. Two readers assessed both datasets for vascular definition (from 0, not visualized, to 3, excellent definition), artifacts, and ostial diameters. Statistical analysis was performed using Wilcoxon, paired t test, and kappa coefficient.


RESULTS
On SSFP MRA, readers 1 and 2 graded 96.4% (160/166) and 97% (161/166) of the segments as having diagnostic visibility and sharpness, respectively (k = 0.82). On CE-MRA datasets, all segments were graded as having diagnostic visibility and sharpness by both readers (k = 0.86). No significant difference existed for visibility and sharpness of pulmonary venous segments between the datasets for each reader (P[r] > 0.05). Reader 1 (2) identified 27 (28) and 35 (32) motion artifacts on SSFP and CE-MRA datasets, respectively. No significant difference was found to exist between ostial diameters on CE-MRA and SSFP datasets (P > 0.05).


CONCLUSIONS
Our study shows that 3D depiction of PVs without intravenous contrast is feasible with nonslice-selective SSFP MRA. This novel MRA technique may be used in certain patients with atrial fibrillation to assess the number and size of PV ostia draining to the left atrium prior to radiofrequency ablation.
Krishnam
Mayil S
MS
Department of Radiological Sciences, UCLA Medical Center, Los Angeles, CA 90095-7206, USA. mkrishnam@mednet.ucla.edu
Tomasian
Anderanik
A
Malik
Sachin
S
Singhal
Aparna
A
Sassani
Alex
A
Laub
Gerhard
G
Finn
J Paul
JP
Ruehm
Stefan
S
D000465:Algorithms; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011667:Pulmonary Veins / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media