MR EVALUATION OF THE BRAIN IN CENTRAL DIABETES-INSIPIDUS

Objective. To evaluate the role of magnetic resonance (MR) imaging in determining the cause of central diabetes insipidus (CDI) by using MR imaging to describe the findings in the hypothalamic-pituitary area in patients with CDI. Methods. Thirty-one cases of clinically proved CDI were prospectively studied. A control study was also conducted in 200 normal subjects. MR imaging was performed on a 1.0 T superconductive unit with T-1-weighted images obtained in the sagittal, coronal and ax ial planes. Results. Hypothalamic-pituitary masses or structural chang es were identified in 26 cases and normal structures in 5. The normal high signal intensity of the posterior pituitary lobe was absent in 29 cases, but remained unchanged in 2. In the control group, the frequen cy of the high signal of the posterior lobe was 93%. Conclusions. The absence of the normal high signal in the posterior pituitary lobe is c losely related to the loss of hypothalamic-pituitary function. MR imag ing is very sensitive in demonstrating the changes in this area in CDI and it can provide an accurate diagnosis when combined with the clini cal information.