High resolution pituitary gland MRI at 7.0 tesla: a clinical evaluation in Cushing's disease

To evaluate the detection of pituitary lesions at 7.0 T compared to 1.5 T MRI in 16 patients with clinically and biochemically proven Cushing's disease. In seven patients, no lesion was detected on the initial 1.5 T MRI, and in nine patients it was uncertain whether there was a lesion. Firstly, two readers assessed both 1.5 T and 7.0 T MRI examinations unpaired in a random order for the presence of lesions. Consensus reading with a third neuroradiologist was used to define final lesions in all MRIs. Secondly, surgical outcome was evaluated. A comparison was made between the lesions visualized with MRI and the lesions found during surgery in 9/16 patients. The interobserver agreement for lesion detection was good at 1.5 T MRI (κ = 0.69) and 7.0 T MRI (κ = 0.62). In five patients, both the 1.5 T and 7.0 T MRI enabled visualization of a lesion on the correct side of the pituitary gland. In three patients, 7.0 T MRI detected a lesion on the correct side of the pituitary gland, while no lesion was visible at 1.5 T MRI. The interobserver agreement of image assessment for 7.0 T MRI in patients with Cushing's disease was good, and lesions were detected more accurately with 7.0 T MRI. (orig.)