In order for relaxation times to be used in clinical diagnosis, the precision of the measurement must be determined. The authors measured T1, T2, and proton density in a phantom and in human volunteers to determine the reproducibility of the method. The coefficient of variance of T1 measurements in the phantom during a 15-month period with two software upgrades was 5%. Variance of T2 measurements with any given software was 4% or less, and overall in the 15-month period, with two software changes, the T2 reproducibility was between 6% and 9%. The reproducibility is sufficiently high that precise clinical measurements of T1, T2, and proton density are feasible.

MR angiography with MS-325 provides significant improvement in effectiveness over unenhanced MR (and minimal and transient side effects) at a dose of 0.03 mmol/kg and was safe and effective for MR evaluation of patients with aortoiliac occlusive disease.

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The authors measured the T1 and T2 of cerebral tissue in 164 volunteers aged 5-90 years and correlated T1 and T2 with age, gender, and various demographic variables. A weak correlation with statistical significance was found between age and T1 and T2 in white and gray matter structures. The T1 and T2 in the telencephalon increased by about 0.1% per year. No correlation of T1 or T2 with any other demographic, life-style, or medical factors was found.