Time-resolved analysis of coronary vein motion and cross-sectional area

Coronary Endothelial Dysfunction in Women With Type 2 Diabetes Measured by Coronary Phase Contrast Flow Velocity Magnetic Resonance Imaging

OBJECTIVE

The aim of this study was to determine if differences in coronary endothelial function are observed between asymptomatic women with type 2 diabetes mellitus (DM) and control subjects using coronary phase contrast flow velocity magnetic resonance imaging in response to cold pressor stress, an established endothelium-dependent vasodilatory stress.

METHODS

Phase contrast flow velocity imaging of the right coronary artery was performed in 7 asymptomatic premenopausal women with DM and 8 healthy female participants in response to the cold pressor test at 3 T.

RESULTS

There was no significant difference in percent increase in coronary flow velocity from rest to peak flow velocity between DM and control subjects (32% ± 22% vs 46% ± 17%; P = 0.11). However, percent increase in coronary flow velocity was lower in DM than in control subjects (-3% ± 14% vs 31% ± 30%; P = 0.01) during the second minute of cold pressor stress, when endothelial-mediated vasodilation should occur.

CONCLUSIONS

Asymptomatic women with DM demonstrate reduced coronary flow velocity during the second minute of cold pressor stress, indicating coronary endothelial dysfunction.

Optimization of free-breathing whole-heart 3-dimensional cardiac magnetic resonance imaging at 3 tesla to identify coronary vein anatomy and to compare with multidetector computed tomography

OBJECTIVE

This study optimizes use of 3-T magnetic resonance imaging (MRI) to delineate coronary venous anatomy and compares 3-T MRI with multidetector computed tomography (MDCT) measurements.

METHODS

The study population included 37 consecutive subjects (22 men, 19-71 years old). Whole-heart contrast-enhanced MRI images at 3 T were acquired using segmented k-space gradient echo with inversion recovery prepared technique. The MDCT images were obtained using nonionic iodinated contrast.

RESULTS

The coronary sinus and great cardiac, posterior interventricular, and anterior interventricular veins were visualized in 100% of cases by both MRI and MDCT. Detection of the posterior vein of the left ventricle and the left marginal vein by MRI was 97% and 81%, respectively. Bland-Altman plots showed agreement in ostial diameter measured by both modalities with correlation coefficients ranging from 0.5 to 0.76. Vein length and distances also agreed closely.

CONCLUSIONS

Free-breathing whole-heart 3-dimensional MRI at 3 T provides high-spatial-resolution images and could offer an alternative imaging technique instead of MDCT scans.

Performance of 3D, navigator echo-gated, contrast-enhanced, magnetic resonance coronary vein imaging in patients undergoing CRT

PURPOSE

The aims of this study were to evaluate the ability of contrast-enhanced MRI to visualize the coronary veins with validation by the gold standard, X-ray venography, and to determine whether MRI can visualize the coronary vein branch used for left ventricular (LV) lead implantation.

MATERIALS AND METHODS

Nineteen (19) patients undergoing cardiac resynchronization therapy (CRT) received a cardiac MRI at 1.5T 1 week before treatment. Coronary vein images were acquired using a 3D, navigator- and ECG-gated, contrast-enhanced, inversion-recovery, fast low-angle shot (FLASH) sequence. X-ray venography was performed during the CRT procedure to image the coronary venous anatomy and the LV lead location. MRI coronary vein images were graded on a 0-3 scale (0 = nonexistent, 1 = poor, 2 = good, 3 = excellent). MRI and X-ray venogram images were also graded using a binary visible/not visible scheme to compare the visibility of the coronary veins.

RESULTS

The mean visibility scores for the coronary sinus, the posterior interventricular, the posterior vein of the left ventricle, the left marginal vein, and the anterior interventricular were 3.0 ± 0.2, 2.3 ± 0.7, 1.6 ± 1.1, 1.9 ± 0.8 and 2.4 ± 0.9, respectively. When compared to X-ray venography, MRI was capable of visualizing 90% of veins and all of the veins used for LV lead implantation. The vein used for LV lead implantation had an average vein image quality score of 1.9 on MRI images.

CONCLUSIONS

Contrast-enhanced MRI was capable of visualizing 90% of the coronary venous anatomy and was able visualize the vein used for LV lead implantation in all patients.