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

Abstract

Hypermanganesaemia is reported in patients on long-term parenteral nutrition. Deposition of manganese, giving high signal on T1-weighted images, may involve the basal ganglia. MRI in nine patients (mean age 51 years, range 31–75 years) on long-term parenteral nutrition (mean duration 30 months, range 6–126 months), demonstrated high signal in the anterior pituitary gland on T1-weighted sagittal and coronal images. The gland appeared normal on T2-weighted images. Signal intensity in the basal ganglia on T1-weighted images 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 μmol/l, mean 1.87 μmol/l). The high signal in the anterior pituitary gland was probably related to deposition of paramagnetic substances, especially manganese.