The authors describe the magnetic resonance (MR) imaging appearance of
the head of the right caudate nucleus in patients who have undergone
adrenal medullary transplant surgery for Parkinson disease. All four p
atients examined showed some clinical improvement after surgery. The M
R images acquired 4-6 months postoperatively showed no evidence of cau
date atrophy. Three of the four patients showed some increase in size
of the operated caudate head relative to preoperative studies. Neither
cavitation nor high signal intensity on T2-weighted images was eviden
t within the caudate head. The one patient studied after administratio
n of gadopentetate dimeglumine showed no abnormal enhancement. These i
mages provided a description of the transplant site and also suggested
that the clinical improvement seen was not due to simple ablation of
caudate tissue or to postoperative inflammation. The increase in size
of the caudate head also suggested that some implanted tissue may have
remained in these patients at the time the MR images were acquired.