Get your Health question answered in 3 easy steps
A Doctor will be with you shortly
Ask a Doctor Now
152 Doctors are Online

what is dose modulation in a CT scan procedure?

User rating for this question
Answered by

ENT Specialist
Practicing since : 1991
Answered : 2445 Questions
what is dose modulation in a CT SCAN PROCEEDURE
The ENT is requesting CT of sinuses in the coronal position
My thyroid works fine but I have Hashimoto's thyroditis starting
I also had malignant melanoma in situ, stage 0 on my left calf
What sort of protection should i request from the CT TECH for my thyroid and my eyes
Thank you in avance for your time
e-mail: YYYY@YYYY
Respectfully, XXXXXXX
Posted Fri, 2 Aug 2013 in Ear, Nose and Throat Problems
Answered by Dr. Sumit Bhatti 2 hours later

Thank you for your query.

1. You may discuss this with your Radiologist and ENT Specialist. Dose modulation may affect the image resolution.

2. If it is just a screening CT, lower resolution images may be fine. Avoid any contrast injection (get a plain CT) as it also involves a repeat scan.

3. Newer multi-slice CT Scan machines may deliver an ionizing radiation dose equivalent to 200-400 x-rays in high resolution mode. This must be weighed against the benefits.

4. The thyroid is not part of the study. The Orbit will receive ionizing radiation during a Sinus CT.

5. MRI is also an option, however bone is best seen on a CT. You may combine a screening Ct with an MRI for more resolution if there is a sinus disease.

I hope that I have answered your query. If you have any further questions, I will be available to answer them.

Above answer was peer-reviewed by
Follow-up: what is dose modulation in a CT scan procedure? 3 hours later
The symptom that prompted all this is a reduced ability to detect odors. partial anosmia. This problem is a couple of years old already...I had it checked by an ENT about a year ago.He said, that sometimes, viruses wipe out some of our nasal odor detectors. He said not to worry, because the onset wasn't abrupt but rather gradual, and it is partial...
The ENT I saw on 7/2/13 checked my nostrils with a scope-no obstructions or polyps seen. He gave me flonase to use:2 shots/nostril/day. he also recommended the CT Scan to see if anything hidden is causing the problem. Is this treatment overkill?...
My dentist recommended the Kodak 9500 Cone Beam CT 3D Imaging that has excellent resolution with A LOT less radiation. She already communicated, on my behalf, with a periodontist who has this machine in his office, and is urging me to go that route. The ENT,however, wants the conventional CT Scan. WHAT DO YOU RECOMMEND?!
I also have read that this symptom could be a precursor for Parkinsons/Alzheimers!YIKES!...

My cousin, who is an oncologist, recommended an MRI instead of a CT Scan
what is your opinion?
Thank you ,
Respectfully, XXXXXXX
Answered by Dr. Sumit Bhatti 17 hours later

Thank you for writing back.

1. Since you need to investigate Hyposmia and no nasal or sinus disease is expected, you may go ahead for an MRI which will be able to visualize the olfactory tract better than the conventional CT and the CBCT (Cone Beam CT).

2. The conventional CT may be done later if required. CBCT will require dedicated software to generate comparable resolution images as it is being used mainly for dental imaging.

3. Parkinson's disease and Alzheimer's disease will have additional symptoms and signs. For example, the motor signs in Parkinson's and the progressive memory loss in Alzheimer's are prominent in sustained follow up.

4. While it is true that viral infections may damage the sense of smell, most recovery takes place between this time period of a couple of years. Steroids are the main stay of treatment to reduce any inflammation. If not contraindicated, oral steroids are used.

5. Hyposmia affects the flavour of food. You may check if you can smell strong smells such as cooking gas (methyl mercaptan). This reduces the dangers of missing a gas leak or smoke in the kitchen / house.

6. Did you have any viral fever, fungal infection, head injury or occupational / recreational exposure to chemicals such as Cadmium (paint, pigment, plastics, batteries)?

7. Have you tried Zinc supplements and Multi-vitamins and anti-oxidants?

I hope that I have answered your query. If you have any further questions, I will be available to answer them.

Above answer was peer-reviewed by
Share on Facebook
Share on Twitter
Share on Google+
Question is related to
Medical Topics

The user accepted the expert's answer

Ask an ENT Specialist

© Ebix, Inc. All Rights Reserved.
All the information, content and live chat provided on the site is intended to be for informational purposes only, and not a substitute for professional or medical advice. You should always speak with your doctor before you follow anything that you read on this website. Any health question asked on this site will be visible to the people who browse this site. Hence, the user assumes the responsibility not to divulge any personally identifiable information in the question. Use of this site is subject to our Terms & Conditions
Already Rated.
Your rating:

Ask a Doctor