What is up family! We are pleased to welcome you back to our weekly series where we help share some interesting articles to learn together. Last week, Duc shares some awesome facts about TEE. Can you answer this week’s challenge question:
TEE allows use to get high resolution images of the thoracic aorta by using a probe that travels through what structure? Comment the answer down below, no peaking!!
This week, I wanted to share this interesting article from the US FDA regarding a topic which some have raised in the past — Radiation exposure from CT scans: https://www.fda.gov/radiation-emitting-products/medical-x-ray-imaging/what-are-radiation-risks-ct
As we discussed in prior series, CT scans uses a series of X-rays to create cross-sectional images of the body. Sometimes, your doctors may opt to use iodine-based contrast dye to help better visualize vessels and lumens in your aorta.
One feared risk of CT scans (particularly for those that have undergone several scans throughout their lifetime) is the risk of developing cancer from repeated radiation exposure.
The reasoning behind this fear is that high-dose ionizing radiation (such as those used in chemotherapy) can cause damage to the DNA of cells, which may cause them to develop into malignancy.
However, it is generally believed that the probability of absorbed x-rays directly inducing cancer or causing mutations in your DNA is very small when considering the low amount of radiation used in CT procedures. Other feared risks, such skin injury or reddening are also very rare.
In fact as of the time of writing this article, no major study has proven an association between CT radiation exposure and the development of cancer-forming mutations in healthy cells.
One’s risk of developing cancer from radiation exposure depends on numerous factors including body area exposed, age during exposure, gender, and dose of radiation.
Below is a table summarizing the estimated dose of radiation exposure in different medical tests taken from a study by Dr. McCollough at the Mayo Clinic - https://pubmed.ncbi.nlm.nih.gov/26434964/
As you can see a CT of the chest / abdomen for scanning the aorta would range from 7 to 8 mSv of radiation and most tests do not exceed a radiation effective dose of more than 10 mSv.
For context, an exposure to such a dose is estimated to increase the probability of malignancy by 1 / 2000. To compare, the natural risk of cancer in the US is approximately 400/2000 or 1 in 5. This means that the risk of radiation exposure during these tests leading to cancer is much smaller than the natural risk of developing cancer during one’s lifetime.
When factoring in the combined natural risk of cancer (400/2000) in the US and the mildly added risk of CT radiation exposure (1/2000), the risk of developing cancer increased from 400/2000 to 401/2000.
Please note- the decision to undergo CT scans and the amount of radiation used is highly tailored to each patient and will include an evaluation of their age, risk status, and therapeutic benefit of the test they are undergoing. For younger patients, particularly those needing a CT of their abdomen/ pelvis during pregnancy, doses may be adjusted accordingly to decrease lifetime radiation exposure to the patient and/or their fetus.
Be sure to always inform your doctor of prior radiation exposure and share any fears you may have with them! Shared decision-making is key.
Thank you very much for joining us this week. We hope you are enjoying our weekly posts. If you are, please help share them with your friends, family and other loved ones! It is a pleasure to be with you on this journey. Take care and until next time, remember to always Think Aorta <3