Quantum mechanics

HARP

Cardiac cycle

Image quality

Diastole

Nuclear magnetic resonance

Cardiology

Computer science

Strain (injury)

Physics

Blood pressure

Anatomy

Image (mathematics)

Systole

Internal medicine

Contrast-to-noise ratio

Artificial intelligence

Medicine

Nuclear medicine

Journal of Magnetic Resonance Imaging

Purpose To determine whether imaging at 3 T could improve and prolong the tag contrast compared to images acquired at 1.5 T in normal volunteers, and whether such improvement would translate into the ability to perform strain measurements in diastole. Materials and Methods Normal volunteers ( N = 13) were scanned at 1.5 T (GE Signa CV/i) and 3.0 T (GE VH/i). An ECG‐triggered, segmented k‐space, spoiled‐gradient‐echo grid‐tagged sequence was used during cine acquisition. Tag contrast was determined by the difference of the mean signal intensity (SI) of the tagline to the mean SI of the myocardium divided by the standard deviation (SD) of the noise (CNR tag ). Matched short‐axis (SA) slices were analyzed. Strain measurements were performed on images using a 2D strain analysis software program (harmonic phase (HARP)). Results The average CNR tag over the cardiac cycle was superior at 3 T compared to 1.5 T for all slices (3 T: 23.4 ± 12.1, 1.5 T: 9.8 ± 8.4; P &lt; 0.0001). This difference remained significant at cycle initiation, end‐systole, and the end R‐R interval (at cycle termination: 3 T = 14.0 ± 11.0 vs. 1.5 T = 4.4 ± 3.5; P &lt; 0.01). Strain measures were obtainable only in early systole for 1.5 T images, but were robust throughout the entire R‐R interval for 3 T images. Conclusion Imaging at 3 T had a significant benefit for myocardial tag persistence through the cardiac cycle. The improvement allowed strain analysis to be performed into diastole. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.

Myocardial tagging and strain analysis at 3 Tesla: Comparison with 1.5 Tesla imaging