Purpose: Symptoms, macroscopic appearances and microscopic findings of Rathke's cleft cysts with magnetic resonance (MR) imaging.
Patients and Methods: We analyzed the data from 31 patients with pathologically confirmed Rathke's cleft cysts. MR appearances were evaluated on T₁WI, T₂WI and contrast T₁WI. Symptoms, macroscopic appearances and pathological findings were obtained from available medical records. We analyzed the images according to the following criteria:
1. findings on the location and shape of the lesions and form of the lesional wall;
2. the relationship between the maximum diameter of the lesions and symptoms;
3. the relationship between MR and macroscopic appearance;
4. the sites of adjacent contrast enhancement.
Results: The lesions were located mostly in both the intrasellar and suprasellar regions for a total of 87%. All lesions revealed either an oval or dumbbell shape with a smooth lesional wall. When correlated with physical symptoms, asymptomatic cases were associated with smaller lesions, while visual disturbances and dizziness were associated with relatively larger lesions. MR lesion signal intensity was related to the content of macroscopic appearance to some degree: the selected lesions showed shortening of T₁ and T₂ relaxation times in relation to the increase in protein concentration. This should have been macroscopically reflected in the color and turbidity of the liquid within the cyst. Adjacent contrast enhancement around the lesion was found at various sites, but anterior enhancement was most frequent. Circumferential enhancement was revealed to be derived from inflammatory changes.
Conclusion: Rathke's cleft cyst exhibits a varied MR signal. It may be difficult to differentiate from craniopharyngioma from the intensity alone.