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Radiology Physics – Radionuclides

As a third installment in a series of articles on radiology physics, I’ve included a good summary table of important radionuclides to know for the ABR Core examination. This test also contains a component of the Radioisotope Safety Examination (RISE) which must be passed to obtain an Authorized User status from the ABR. Part of the RISE is contained on the core examination, and part of it is contained on the certifying examination which is taken 15 months after residency graduation. The second portion of the Radioisotope Safety Exam (RISE) is integrated into the Certifying Exam. The RISE elements on the Certifying Exam will be devoted to clinically-oriented practice scenarios which emphasize evaluation of practical knowledge of radioisotope safety and handling, as well as regulatory compliance. For more details, please refer to the RISE Study Guide.

I created the below table to have a “go to” resource for the important radionuclides, mode of production and decay, half lives, and important photopeaks all in one place. One that is not on there is Radium 223, which you probably should know is used to treat prostate cancer bone metastases (like samarium and strontium), its an alpha emitter, and it improves survival. Enjoy:

Radionuclide Production Method Half Life Decay Mode Radiation Type and Energy (KeV)
Carbon 11 Cyclotron 20 minutes β+, EC Gamma 511
Nitrogen 13 Cyclotron 10 minutes β+ Gamma 511
Fluorine 18 Cyclotron 110 minutes β+ Gamma 511
Cobalt 57 Cyclotron 271 days EC Gamma 122
Gallium 67 Cyclotron 3.26 days EC Gamma 93, 185, 300, 394
Rubidium 82 Generator 1.3 minutes β+, EC Gamma 511
Strontium 89 Nuclear reactor/neutron activation 51 days β- Beta 1491
Yttrium 90 Generator 64 hours β- Beta 2284
Molybdenum 99 Nuclear reactor/fission 2.75 days β- Gamma 740
Technetium 99m Generator 6 hours IT Gamma 140
Indium 111 Cyclotron 2.8 days EC Gamma 171, 245
Iodine 123 Cyclotron 13 hours EC Gamma 159
Iodine 131 Nuclear reactor/fission 8.04 days β- Gamma 284, 364
Xenon 133 Nuclear reactor/fission 5.25 days β- Gamma 81
Cesium 137 Nuclear reactor/fission 30 years β- Gamma 662
Samarium 153 Nuclear reactor/neutron activation 46 hours β- Gamma 103
Thallium 201 Cyclotron 3.04 days EC Gamma 167

Key: EC – Electron Capture; IT – Isomeric transition

The graph below, a representation of the modes of radionuclide decay, is definitely high yield material for the ABR Core exam.

Summary of Radionuclide decay graph


About radiologypics

I am a radiology physician from California, USA.


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