Quantification of morphologic and hemodynamic severity of coarctation of the aorta by magnetic resonance imaging.
OBJECTIVE
As the morpholgic severity of coarctation of the aorta is difficult to assess, especially after previous repair, the value of the technique of multiplanar reconstruction of magnetic resonance imaging data to achieve a 3-dimensional reconstruction of the aortic arch was evaluated and compared to hemodynamic measurements.


RESULTS
We performed 30 examinations in 27 patients aged from 6 to 54 years, with a mean of 21 years, by magnetic resonance imaging using a 1.5Tesla scanner with a standard body coil. Measurements of flow across the coarctation were performed using phase shift velocity mapping, and peak velocity was calculated at the site of stenosis. Aortic cross-sectional area before, at, and beyond the stenosis was reconstructed 3-dimensionally to calculate a percentage degree of stenosis. Morphologic severity of stenosis was correlated to invasively assessed hemodynamic gradients and morphologic data from biplane angiography in 23 patients. Among the 30 examinations, 24 patients had been previously treated by either surgery, in 17 patients, or balloon dilation, while 6 had native coarctation. 3-dimensional reconstruction was possible in all and better delineated the anatomy concerning the hemodynamic relevance of stenoses even as compared with biplane angiography. The correlation between severity of narrowing assessed by diameter measurements in the biplane angiography and 2-dimensional magnetic resonance imaging was r = 0.94, and multiplanar reformation with 2-dimensional magnetic resonance imaging was r = 0.87 with a tendency of higher grading with the 3-dimensional technique (p = 0.0001). The correlation of 2-dimensional magnetic resonance imaging with invasively measured hemodynamic gradients was r = 0.67 versus r = 0.74 for the areas assessed by multiplanar reformation, indicating that the hemodynamic relevance of a morphological approach to evaluate the degree of a stenosis should better be assessed 3-dimensionally.


CONCLUSIONS
The 3-dimensional reconstruction of the morphologic severity of coarctation offers additional information over conventional imaging especially in patients with kinking, complex geometry, or collaterals, in whom hemodynamic measurements can become unreliable.
Gutberlet
M
M
Department of Diagnostic Radiology and Nuclear Medicine, Charité Campus Virchow Klinikum, Berlin, Germany. matthias.gutberlet@charite.de
Hosten
N
N
Vogel
M
M
Abdul-Khaliq
H
H
Ehrenstein
T
T
Amthauer
H
H
Hoffmann
T
T
Teichgräber
U
U
Berger
F
F
Lange
P
P
Felix
R
R
D000293:Adolescent; D000328:Adult; D000792:Angiography; D001017:Aortic Coarctation / Q000145:classification* / Q000175:diagnosis / Q000503:physiopathology; D002648:Child; D003097:Collateral Circulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011312:Pressure; D012720:Severity of Illness Index