Spin-spin relaxation of brain tissues in systemic lupus erythematosus. A method for increasing the sensitivity of magnetic resonance imaging for neuropsychiatric lupus.

OBJECTIVE

To correlate the spin-spin relaxation time (T2) of brain tissue in neuropsychiatric systemic lupus erythematosus (NPSLE) with the patient's clinical condition.

METHODS

T2 values were determined in 54 SLE patients and 45 non-SLE controls at 1.5 Tesla, using intensity from multi-echo magnetic resonance (MR) images fitted to an exponential decay curve with rate-constant T2.

RESULTS

The T2 of white matter was increased in SLE patients compared with controls (P = 0.01) and was increased in those patients who had previously experienced major NPSLE: Patients with acute diffuse neurologic manifestations (seizures, psychosis, coma) demonstrated a longer T2 of the gray matter (mean +/- SD 92.75 +/- 6.35 ms, n = 10) than did other SLE patients (mean +/- SD 79.61 +/- 5.04 ms, n = 44) (P = 0.02 by t-test), which suggests acute cerebral edema. The mean T2 values of reversible and nonreversible focal lesions were significantly different (P < 0.02), indicating different microenvironments and micropathology.

CONCLUSION

Quantitative T2 measurement extends the utility and sensitivity of conventional MR imaging for evaluating NPSLE: