QUESTION: Hi and thanks in advance!
I went into the ER recently for severe pain in my abdomen. The doctor ordered an abdominal/pelvic CT scan. The recorded voice told me to hold my breath 3 times as the machine went back in forth 3 times so I'm assuming that I was scanned THREE TIMES?! They also said that they can't protect my breasts because they need to get the organs close by. I don't know if this is the standard procedure and I am terrified now of the amount of radiation I received. The tech did say that the machine is "low-dose". I am a 36 year old female with 3 young kids. I would appreciate any advice you could give me as I am a bit of a wreck. Angie
ANSWER: Hi, Angela.
You are correct. You were scanned three times. Your scan was probably ordered with and without contrast. And this is a standard procedure.
The first scan generates the localizer or scout image upon which the CT tech plans the rest of the scan. The second pass through the scanner takes cross-sectional pictures without contrast (if you were a loaf of bread, each picture would be a slice). I'm guessing the third pass was taken after a contrast injection.
Radiologists find it very useful to compare images without contrast to the same location with contrast. In this case, your ordering physician (the ER doctor) determined that the benefits of comparing images without to those with contrast outweighed the risks involved in exposing you to more radiation.
Here is a website with some info about radiation dose and the amount of increased risk of developing cancer: http://www.radiologyinfo.org/en/info.cfm?pg=safety-xray
It sounds like you received the lowest dose possible. That dose is comparable to natural background radiation for 7 years. Though 20mSv does give you a Moderate estimated lifetime risk of fatal cancer from that exam.
I would say not to worry about exposure you've already received. There is nothing you can do about that now. What you can do is minimize your exposure to diagnostic radiation from now on. Before you have even one more x-ray, my advice is to ask the ordering physician if his treatment of your injury or condition will depend on the results of the x-ray.
For example, there's not much you can do for a broken toe. Your doctor may tell you to immobilize it and wait for 6 weeks, whether it's broken or just sprained. In that case, his treatment would be the same with or without an x-ray. On the other hand, if the results of your x-ray exam will determine which treatment you receive, then the benefits from having the exposure will outweigh the risks of contracting cancer from diagnostic radiation.
Hope this helps,
---------- FOLLOW-UP ----------
QUESTION: Thank you for your response. It was an abdominal/pelvic CT WITHOUT contrast. Everything you wrote in your first response stands? Also... No one told me to remove my jeans or asked me about jewelry. Will the zipper from my jeans expose me to more radiation or mess up my results (they were normal)? Thank you SO much!
Well, if your CT was ordered without contrast, the reason you went in and out of the scanner 3 times may have been because the technologist had to repeat the initial scout/localizer image.
If the tech didn't see all of your abdomen/pelvis from the bottom of your lungs to your pelvic bone just below your bladder, (s)he extended the field of view and repeated the scout acquisition again. It's important to see both areas in order to plan the scan correctly. There's no way to know for sure, though.
If that is the case, then you got half as much radiation as you would have if you'd had contrast, too. So your estimated dose would be 3-4 mSv, equivalent to approximately 3 years exposure to background radiation.
As for being scanned with your jeans on, that would not have increased the radiation dose you received. It would have created a metal artifact in your images, which may have obscured some of your anatomy.
I would never scan an abdomen/pelvis with a zipper in the way if I could help it. I would have unzipped the patient's pants and tried to pull them down far enough so that all metallic objects would be out of the field of view. To leave a zipper in the area of interest is lazy/sloppy work in my opinion.
It's my pleasure to help,