High signal in the adenohypophysis on T1-weighted images presumably due tomanganese deposits in patients on long-term parenteral nutrition

Hypermanganesaemia is reported in patients on long-term parenteral nutritio n. Deposition of manganese, giving high signal on T1-weighted images, may i nvolve the basal ganglia. MRI in nine patients (mean age 51 years, range 31 -75 years) on long-term parenteral nutrition (mean duration 30 months, rang e 6-126 months), demonstrated high signal in the anterior pituitary gland o n T1-weighted sagittal and coronal images. The gland appeared normal on T2- weighted images. Signal intensity in the basal ganglia on T1-weighted image s was increased in all patients. Endocrine assessment showed no significant abnormality. Neurological examination showed a mild parkinsonian movement disorder in one patient. Hypermanganaesemia was present in all nine (1.3-2. 8 mu mol/l, mean 1.87 mu mol/l). The high signal in the anterior pituitary gland was probably related to deposition of paramagnetic substances, especi ally manganese.