Proton magnetic resonance relaxation times and biomechanical properties of human vascular wall. In vitro study at 4 MHz.

OBJECTIVES AND RATIONALE: Previous studies have suggested a relationship between tissue magnetic resonance (MR) relaxation times and its biomechanical behavior. To further investigate this relationship, the authors studied 41 human vascular wall samples from different anatomic localizations, including systemic and pulmonary arterial, as well as venous tissues. METHODS: The authors measured water content, proton MR T1 and T2 relaxation times, and two viscoelastic parameters of the samples at 4 MHz. RESULTS: T2, water content, and both viscoelastic variables significantly differed among the five anatomic localizations (P less than .05). Both T1 and T2 were significantly (P less than .05) and linearly related to viscoelastic parameters. Multiple linear regression showed that both viscoelastic parameters of a sample can be predicted from the measured values of T1 and T2. CONCLUSIONS: These results provide a basis for characterizing the mechanical stress of a tissue by knowing its MR relaxation times.