Yasuo Amano MD, Presenter: Nothing to Disclose

Tatsuo Kumazaki, Abstract Co-Author: Nothing to Disclose

When the late myocardial enhancement is assessed in cases of right ventricular (RV) myocardial damages using contrast-enhanced inversion-recovery (IR) magnetic resonance (MR) imaging, the null point of the RV myocardium may be confirmed. The purpose of this study was to assess differences in the null points of myocardium between the RV and left ventricle (LV) in contrast-enhanced MR imaging.

Sixteen patients with cardiac diseases were examined using a 1.5-T MR imager. IR multi-shot gradient-echo echo-planar fast T1 mapping imaging and delayed IR gradient-echo imaging were performed after ten minutes of a 0.15 mmol/kg gadolinium injection in order to assess the null points and signals of the RV and LV myocardia. The differences in these values between the RV and LV were quantitatively evaluated.

In seven of the 16 patients, the null points of the RV myocardium were 21–176 ms (mean, 66 ms) shorter than those of the LV myocardium in the fast T1 mapping images. The null points of both ventricles were same in the remaining nine patients. The RV myocardial signals were significantly higher than the LV myocardial signals in both fast T1 mapping images and delayed IR spoiled gradient-echo images (P< 0.05). In the delayed IR spoiled gradient-echo images, the differences between RV and LV myocardial signals tended to be larger in the seven patients who had some intervals between the null points of the RV and LV myocardium than in the nine patients who had no intervals (P = 0.081).

The null points of the RV myocardium may be shorter than those of the LV myocardium in some patients. A fast T1 mapping imaging or delayed IR gradient-echo imaging with an inversion time shorter than the null point of the LV myocardium should be performed to evaluate the late enhancement of the RV myocardium.

Amano, Y, Kumazaki, T, Null Point of the Right Ventricular Myocardium in Contrast-enhanced Inversion-recovery MR Imaging: A Comparison with Null Point of the Left Ventricular Myocardium.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4404528.html