What is Nuclear Medicine

1. What is Nuclear Medicine

2. Nuclear Medicine Nuclear medicine specialists use safe, painless, and cost-effective techniques to image the body and treat disease. In imaging, the radiopharmaceuticals are detected by special types of cameras that work with computers to provide very precise pictures about the area of the body being imaged.

3. What Happens During a Nuclear Medicine Procedure? In a nuclear medicine test, small amounts of radiopharmaceuticals are introduced into the body by injection, swallowing, or inhalation. The amount of radiopharmaceutical used is carefully selected to provide the least amount of radiation exposure to the patient but ensure an accurate test

4. A special camera (PET, SPECT or gamma camera) is then take pictures of your bodyused to Nuclear medicine differs from an x-ray, ultrasound or other diagnostic test because it determines the presence of disease based on biological changes rather than changes in anatomy.

5. index 1- Radiation and it’s device 2-Pet 3-Spect

6. The origin of nuclear medicine started with the invention of the cyclotron by Ernest Orlando Lawrence (1901-1958) His research centered on the bombarding atoms at high speed in order to produce new particles.  To achieve the high energies needed for the bombardment accelerators were used but the electric potential required was so large (~1 million volts) that is was almost impossible to create a machine that could withstand that magnitude of power.

7. Ernest Lawrence came across a German paper showing that the energy of a particle could be increased by oscillating electric fields.  However, this still did not achieve a high enough speed and the accelerator would have to be extremely long.  Lawrence realized that the idea could be improved on by using a magnetic field to bend the particle beam and force it to become a spiral.  Then each time a circle was completed around the electrode the particle energy would be increased.  This would continue until finally a particle had enough energy to spiral out and with great speed and into a collector.  Alternatively, the target could be placed in the beam path of the outermost circle near a detector.

8. In 1930, Ernest Lawrence built the first cyclotron which was only 4 inches in diameter.  It involved 2 D-shaped magnets, which created a circular magnetic field, with a small gap between them. The alternating electric field accelerated the particles and causing the radius of the circular path to increase until it hit the target.

10. Positron Emission Tomography A positron emitting isotope is introduced into the body usually intravenously and the isotope accumulates in the target organ.  The positron quickly reacts with an electron producing two gamma rays in opposite directions as they collide.  The emitted gamma rays are detected by the PET camera which can pinpoint the location.  Organ malfunction can be assessed due to areas where the radioisotope is in low concentrations is called a cold spot or where it is taken up in excess known as a hot spot.  The organ can also be monitored of a long period of time and display irregular patterns of activity or usual rates of the isotope movement also indicating a malfunction

12. Benefits PET imaging has many advantage over other techniques.  Since the uptake of a radiopharmaceutical is biochemically based and diseases cause a disruption to the usual chemical processes, this technique offers the earliest possible diagnosis of a disease even before the onset of symptoms.  This could mean the disease can be more easily cured or prevented from progressing further.  It also is the one of the best ways of monitoring the success of a treatment and so any adjustments can be correspondingly made. Since the test is painless and non-invasive it has much lower level of risk than with other diagnostic tests.  PET scanning is preferable to x-ray diagnostic tests since it subjects the patient to five times less radiation and it can be used for soft tissue as well as bones.  It is also the most cost-effective method since other techniques are inherently more expensive due to their invasive nature.

13. Applications PET scans can be used to assess blood flow to the brain, the function of the heart, liver and kidneys as well as checking bone development.  The radioisotope used must produce gamma rays of high enough energy in order for them to be detected and have a short half-life so as to minimize the radiation experienced by the patient after the scanning has finished. 

15. Compared with SPECT, PET images have about a factor of four improvement in resolution the instrument is notably more expensive (around $600000) and the cost of a PET scan session typically is 3 times that of a SPECT scan.

16. Isotopes are injected into the body and travel to various locations that include organs of interest. When these isotopes decay, they emit positrons that can then collide with electrons, producing Gamma-ray photons. In this nuclear reaction, two Gamma-rays result and are paired such as to move away from the nuclide in exactly opposite directions. Both Gamma-ray photons are sensed simultaneously by detectors located 180° apart. This double set of radiation photons improves detect abilityut and resolution