[Comparison of the left ventricular stroke volume and fraction measured with MRI and contrast ventriculography].
27 patients who underwent a contrast ventriculography in right anterior oblique at 30 degrees (for various cardiopathies) were studied by MRI with a mean delay of 5.7 +/- 6.2 days. After location of the medio-ventricular area, a diastolic horizontal section (apex of the R wave) and a systolic section (descending portion of the T wave) are carried out using the spin ultrasound technique. The same calculations are used for MRI au X-Ray contours (modified area-length method) by two strictly independent operators. With MRI, the LVSF is under estimated (40.4 +/- 19%) as compared angiography (46.1 +/- 18%). The linear correlation is 0.79 and in half of the patients (13 in 27) the deviation of the LVSF exceeds 10 p. cent. The volumes also tend to be underestimated with MRI (97 +/- 50 and 64 +/- 51 ml for the diastole and systole respectively) compared with angiography (123 +/- 66 and 73 +/- 62 ml), but the difference is only significant for the diastole and the linear correlation coefficients are improved at 0.82 and 0.90. Underestimation of the parameters measured with MRI is the consequence of multiple factors including the imprecise determination of the true telesystole, the marked effect of the partial volume related to the thickness of the section, and especially the obliquity of the plane studied on MRI, compared with the long axis of the heart. The error made by using a calculation algorithm, conceived for projective methods showing the long axis of the modeled ellipsoid, also explains the underestimation of volumes obtained with MRI, tomographic method. The simple technique used here seems especially interesting in the analysis of segmental contraction. Finally, the development of cine-MRI will undoubtedly be extremely beneficial in the study of ventricular contraction and relaxation.
Germain
P
P
Service de Cardiologie, Hôpital de Hautepierre, Strasbourg.
Baruthio
J
J
Mossard
J M
JM
Wecker
D
D
Chambron
J
J
Sacrez
A
A
D000328:Adult; D000368:Aged; D002306:Cardiac Volume; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D013318:Stroke Volume
Comparaison des volumes et des fractions d'éjection ventriculaires gauches mesures en IRM et par ventriculographie de contraste.