The research work in this book was carried out at Radiopharmaceutical division of Bhabha Atomic Research Centre, Mumbai. Radiolabelling of MAO inhibitor drug harmalol with iodine-125 was carried out and evaluated in the management of Parkinsons disease with the aim of its potential application as a diagnostic radiopharmaceutical. This book has been of great value for the students, academicians and researchers in the field of Pharmacy, Radiology, Pharmacology and medical sciences.