Format

Send to

Choose Destination
Eur J Radiol. 2013 May;82(5):734-9. doi: 10.1016/j.ejrad.2011.09.021. Epub 2011 Dec 14.

Musculoskeletal MRI at 3.0 T and 7.0 T: a comparison of relaxation times and image contrast.

Author information

1
Department of Radiology, The Richard M. Lucas Center for Imaging, Stanford University, Stanford, CA 94305-5488, United States. cjordan@stanford.edu

Abstract

OBJECTIVE:

The purpose of this study was to measure and compare the relaxation times of musculoskeletal tissues at 3.0 T and 7.0 T, and to use these measurements to select appropriate parameters for musculoskeletal protocols at 7.0 T.

MATERIALS AND METHODS:

We measured the T₁ and T₂ relaxation times of cartilage, muscle, synovial fluid, bone marrow and subcutaneous fat at both 3.0 T and 7.0 T in the knees of five healthy volunteers. The T₁ relaxation times were measured using a spin-echo inversion recovery sequence with six inversion times. The T₂ relaxation times were measured using a spin-echo sequence with seven echo times. The accuracy of both the T₁ and T₂ measurement techniques was verified in phantoms at both magnetic field strengths. We used the measured relaxation times to help design 7.0 T musculoskeletal protocols that preserve the favorable contrast characteristics of our 3.0 T protocols, while achieving significantly higher resolution at higher SNR efficiency.

RESULTS:

The T₁ relaxation times in all tissues at 7.0 T were consistently higher than those measured at 3.0 T, while the T₂ relaxation times at 7.0 T were consistently lower than those measured at 3.0 T. The measured relaxation times were used to help develop high resolution 7.0 T protocols that had similar fluid-to-cartilage contrast to that of the standard clinical 3.0 T protocols for the following sequences: proton-density-weighted fast spin-echo (FSE), T₂-weighted FSE, and 3D-FSE-Cube.

CONCLUSION:

The T₁ and T₂ changes were within the expected ranges. Parameters for musculoskeletal protocols at 7.0 T can be optimized based on these values, yielding improved resolution in musculoskeletal imaging with similar contrast to that of standard 3.0 T clinical protocols.

PMID:
22172536
PMCID:
PMC3310288
DOI:
10.1016/j.ejrad.2011.09.021
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center