Rathke's cleft cyst: computed tomographic scan and magnetic resonance imaging.

Three patients with histologically proved Rathke's cleft cysts (RCCs) were evaluated with magnetic resonance imaging (MRI) and computed tomographic (CT) scan. Thirteen cases reported in the previous literature were also reviewed to evaluate the MRI features of RCCs and to compare them with CT features. The RCCs had various patterns of signal intensities on T 1-weighted and T 2-weighted MRI. The cysts were well-circumscribed and mainly in the sella turcica extending to the suprasellar cistern with minimal mass effect. Ten of sixteen cases had homogeneous cysts, and six had heterogeneous cysts. The CT scans showed the cysts as low or isodensity, well-demarcated lesions in the sella, that did not enhance with a few exceptions in which a thin ring enhancement was seen. MRI is superior to CT in the evaluation of the RCC, and is particularly useful in surgical planning, although MRI has a limitation on the specific, analytic description of the cyst contents.