DOES MAGNETIC NUCLEAR-RESONANCE IMAGING P ROVIDE COMPLEMENTARY INFORMATION TO CARDIAC-CATHETERIZATION IN THE INVESTIGATIONS OF COARCTATION OF THE AORTA

The results of magnetic resonance imaging (MRI) in the investigation o f coarctation of the aorta were assessed and compared with those of ca rdiac catheterisation. This was a retrospective study of a series of 2 4 patients aged 14 +/- 4 years with a coarctation treated and document ed by MRI. The investigation was performed with a high field 1.5 tesla (Vision, Siemens) system. Twenty-one children underwent comparative r etrograde cardiac catheterisation with angiography and measurement of the peak-to-peak pressure gradient across the isthmus. No significant difference in the measurements of the aorta in MRI spin echo, gradient echo and retrograde aortic angiography were observed. On the other ha nd, there was a slight correlation between the degree of stenosis meas ured by MRI and the peak-to-peak haemodynamic gradient (r = 0.40). Sev en patients had a loss of signal at the level of the aortic isthmus on MRI angiography which correlated with the haemodynamic gradient (p = 0.04). The authors conclude that MRI is a reliable non-invasive techni que of investigating coarctations of the aorta. It gives accurate morp hological data concerning the stenosis and blood flow. MRI should be p art of the investigations of coarctation of the aorta, especially in p oor indication to be able to correct it or consider the results of ang ioplasty or surgical correction.