Week 5: Nuclear Medicine

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I spent this week in Nuclear Medicine reading room and also observed nuclear imaging (NI) procedure.

Nuclear Medicine(NM) involves use of radioactive compounds as imaging contrast for diagnosis and also using radioactive compounds for treatment. These compounds are called radiotracers.

One advantage of using NM is that it allows dynamic imaging,where we can track the radiotracers as they are passing through a body system and cleared out. This enables us to study functionality of some organs such as kidneys.

Some of the NI procedures that I shadowed involved renography. The radiotracer used was 99mTc-MAG3.

A little introduction; MAG3 is a ligand that is linked to the Technetium (99mTc), which is a radioactive molecule releasing Gamma rays on decaying. The ligand attaches to the relevant body tissue due to affinity and allows NI imaging of the tissue as a result of emission released by the radioactive molecules linked to the ligand.

The patient was injected with 99mTc-MAG3 radiotracer. Dynamic imaging was done as the 99mTc-MAG3 radiotracer travelled through the kidneys and cleared to the bladder. The images were then analyzed, plots made,and compared to standard plots to analyze the functionality of the kidneys.

Another procedure was where 99mTc-MDP was IV injected to a patient and after two hours imaging was carried out. The purpose was to diagnose pathologic bone fracture in a young patient( MDP ligand attaches to hydroxyl ????? acid in the bone,which I think the doctor said,is present when there is a high rate bone turnover due to metastasis). The images were then analyzed and it was determined that the patient had malignancy in the imaged location.

I have also shadowed NI analyses reading being used to calculate likelihood of bone fracture in elderly patients, by calculating (by software) bone material density, making plots and comparing them to T-score and Z-score standard plots. Standard T- and Z-score plots provides data on what should be expected of a normal person bone material density in different organs such as the femur and spine. Z-score is age compensated.

Other NI and reading analyses I shadowed was for thyroid and parathyroid in studying cancer tumors.