Question

2) Outline the pertinent radionuclide properties required for the following nuclear medicine procedures and suggest radionuclides: a) A study which attempts to locate blockages or transit difficulties through the colon. The patient is given a radioactive meal and returns for planar images of the abdomen at Ihr 2hrs, 4hrs, 6hrs, 24hrs, 48hrs and, if necessary, day 3 and day 4. (2 Marks) b) A radiopharmaceutical, infused intravenously, that is given as a therapeutic agent that specifically targets certain types of tumour where lesion sizes are typically of the order of 3- 5cm at the time of therapy. (2 Marks) c) Assessment of osteomyelitis in feet: Patients require both a scintigraphic bone scan and a scintigraphic infection scan to investigate areas of matching uptake. It is thus important that the foot remains perfectly still, however these patients are often difficult to image due to size, ill health and poor peripheral circulation, so it is ideal to perform both imaging procedures simultaneously. (Hint: Your answer should also refer to the gamma camera settings required for this study). (2 Marks)

Answer 1

2 a The substance should be water insoluble. It is mixed with water handmade into a clay like material . It gives contrast by forming opaque white mixture . It is swallowed.

B. The biopharmaceutical should be attached to oxygen or glucose. These are taken up by the metabolically active cells and emit gamma rays which is measured in various places in the body. The methodically active cells are tumor cells

C. Radiosubstance tagged to methylene diphosphonate is used. This tagging carries the isotope to throne where it attaches by bonding with hydroxyapetite any increased activity of osteolysis is highlighted by gamma ray emission.

The gamma camera is either positioned at right angles to get better images or in SPECT both cameras are rotated around the body to get better quality images without much discomfort to the patient