PET-CT Scan in Lucknow
Whole-body imaging that shows how tissue is functioning, not just how it looks.
A PET-CT scan combines two images into one: PET shows how active the tissue in your body is, and CT shows exactly where that activity is. Together they reveal disease by its behaviour — often before it has changed the shape of anything — which makes PET-CT central to cancer care.
At Charak, PET-CT is performed with careful attention to the radiotracer dose and reported by nuclear medicine physicians. It is most often used to stage a cancer, to check whether treatment is working, and to look for disease across the whole body in a single study.
Why PET-CT is different from an ordinary scan
Before the scan, a small amount of a radioactive tracer — usually a form of glucose — is injected. Active tissue, including many cancers, takes up more of it, and the PET camera sees exactly where. The CT then pinpoints the anatomy.
This functional view is why PET-CT can find disease that a plain scan misses, judge whether a treated tumour is still active, and survey the whole body in one examination rather than region by region.
A PET-CT scan may be recommended for
- Staging a newly diagnosed cancer
- Checking whether cancer treatment is working
- Looking for cancer recurrence after treatment
- Finding the source of disease when other scans are unclear
- Assessing certain heart and neurological conditions
How to prepare
Preparation for PET-CT is strict because the tracer is a form of sugar — raised blood sugar changes what the scan sees. Follow the fasting and diet instructions carefully; we go through them with you when you book.
- Fast for 4–6 hours before the scan; drink plain water only
- Avoid strenuous exercise for 24 hours beforehand — active muscle takes up the tracer
- Diabetics need specific timing for food and medication — we plan this with you
- After the tracer injection you rest quietly for about an hour before scanning
- Tell us if you are, or might be, pregnant, or are breastfeeding
What to expect on the day
- 01
Check-in & tracer
Your blood sugar is checked and the radiotracer is given through a small vein in the arm.
- 02
The uptake wait
You rest quietly for around an hour while the tracer distributes through the body — moving little helps the images.
- 03
The scan
You lie still on the table as it passes slowly through the scanner; the whole-body study takes 20–30 minutes.
- 04
Afterwards
You can go home and resume normal activity; drinking water helps clear the tracer, which fades within hours.
Common questions
Is the radiation from a PET-CT harmful?
The tracer is short-lived and the dose is kept as low as the study allows. The amount is carefully controlled, fades within hours, and is weighed against the important information the scan provides for your treatment.
Why must I fast and avoid exercise before a PET-CT?
The tracer is a form of glucose, so eating or vigorous exercise sends it to your muscles and gut and away from what the scan needs to see. Fasting and rest give clear, reliable images.
How long does the whole appointment take?
Allow around two hours: check-in and the tracer injection, then about an hour of quiet rest while it distributes, and finally the 20–30 minute scan.
From the health library
Plain-language guides written by the team here — what the test measures, how to prepare, and what the result means.
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