About your scan
Contrast in a PET-CT Scan: — What the Injection Is For
If you have been told your PET-CT includes a contrast injection, you may not know what it is for or what it will feel like. It is a different injection from the PET radiotracer. Most people feel a brief warm flush and nothing more.
Medically reviewed by Dr. C. Raghavendra Reddy, Medical Oncologist, MBBS (Gold Medal) · DNB · DM (Medical Oncology, Gold Medal) · Last reviewed September 2026
- Two injections, two purposes — The PET radiotracer and the CT contrast are completely separate injections with completely different roles in the scan.
- Not always used — Many PET-CTs are done without contrast. Your oncologist decides based on what the scan needs to show.
- The sensation passes quickly — Most people feel warmth or a metallic taste briefly. It is normal and settles on its own.
- Tell the team your health history — Kidney problems, previous reactions to contrast, or taking metformin all affect whether contrast is safe for you.
17+
Cancer Specialists
on Panel
on Panel
96.9%
Breast Cancer
Survival Rate*
Survival Rate*
15,000+
Patients
Treated
Treated
4.8★
Google Rating
(800+ reviews)
(800+ reviews)
CT contrast is an iodine-based dye injected into a vein during the CT portion of your scan. It makes blood vessels and soft tissue easier to see. Not every PET-CT includes it — your oncologist decides based on what needs to be assessed. It is a completely separate injection from the PET radiotracer.
PET-CT at CION starts from Rs 10,499 — among the lowest published prices in Hyderabad, with no hidden charges. Indicative price, as of September 2026.
What does the contrast injection actually do?
CT contrast is an iodine-based liquid injected into a vein in your arm. It travels through your bloodstream and temporarily makes blood vessels and certain soft tissues much more visible on the CT images.
The CT and PET parts of your scan measure different things. The PET detects where metabolically active cells are. The CT shows the structure and anatomy around them. Contrast sharpens that structural picture when more detail is needed — for example, to understand exactly how a tumour relates to nearby blood vessels or surrounding tissue.
Without contrast, the CT component still works. It is used at a lower dose for a process called attenuation correction, which helps the computer interpret the PET data accurately. Contrast is added only when your oncologist has requested a diagnostic-quality CT alongside the PET.
PET-CT Partner Centres
PET-CT Scan Centres in Hyderabad
CION offers PET-CT scans through 4 trusted partner PET-CT centres across Hyderabad, so you can choose the one closest to you. Call 18002028726 and we’ll guide you to the earliest available appointment.
PET-CT Centre — Punjagutta
PET-CT Centre — Himayatnagar
PET-CT Centre — Narayanaguda
These are partner diagnostic centres within the CION network. Toll-free booking: 18002028726.
Meet the Specialists
17+ senior cancer specialists. One panel for your case.
Trained at AIIMS, Tata Memorial, and leading international centres. Combined 150+ years of experience. Every complex case is reviewed by 3+ of them — together.
Medical Oncologist
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Surgical Oncologist
Dr. Muralidhar Muddusetty
MBBS (AIIMS), MS (Surgery) (AIIMS), DNB (Surgical Oncology), MRCS (Edinburgh)
Surgical Oncologist
Surgical Oncologist
Surgical Oncologist
Dr. Vinay Mamidala
MBBS, MS(General Surgery), M.Ch(Surgical Oncology), FMAS, FARIS(Ongoing)
Surgical Oncologist
Radiation Oncologist
Radiation Oncologist
Radiation Oncologist
Hematologist
Interventional Radiologist
Dr. Mohammed Imran
Surgical Oncologist
Dr. Vajja Sandeep Kumar
MBBS, MS (General Surgery), DrNB (Surgical Oncology), FALS Oncology
Surgical Oncologist
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
Get a straight answer from a specialist
45 minutes, your reports reviewed, your questions answered in plain language.
Is contrast given in every PET-CT?
No. Whether contrast is used depends on what your oncologist has asked the scan to answer.
A standard PET-CT for staging or treatment response assessment often does not include contrast. A scan ordered to assess something more specific — how a tumour sits in relation to a major blood vessel, or the fine detail of structures in the neck, chest or abdomen — more commonly includes it.
Your oncologist writes the clinical indication on the scan request. The radiologist at the partner imaging centre confirms whether contrast is appropriate for you before the scan begins. If you are unsure whether your scan includes it, ask at booking or on the day before the radiotracer is given.
What happens on the day contrast is used?
Your health history is checked
Before contrast is given, the team asks about your kidney function, any previous reactions to contrast dye, and whether you take medicines such as metformin. This is not a formality — the answers determine whether contrast is safe for you that day.
An intravenous line is placed
A small cannula is placed in a vein in your arm. This may be the same line used for the PET radiotracer or a separate one. The contrast is injected through this line, timed to coincide with the CT portion of the scan.
The contrast is injected and the CT runs
You will be asked to hold your breath briefly during the CT. Most people notice a warm flush spreading through the body and sometimes a metallic taste in the mouth. Both pass quickly and are a normal response to the contrast.
You wait briefly before leaving
The team will ask you to stay for a short time after the scan is complete. This is standard practice when contrast has been used, to confirm there is no delayed reaction before you go.
A whole-body PET-CT at CION is Rs 10,499 — among the lowest published prices in Hyderabad — with a free Rs 950 oncologist consultation to talk through your report. Indicative price, as of September 2026.
Explore 64 more Preparing For and Having Your Scan Safely topics
Scan Day: What Actually Happens
- Can Someone Stay With Me During the Scan?
- Can You Drive Yourself Home After a PET-CT Scan?
- Can You Have Sedation for a PET-CT Scan?
- Can a PET-CT Scan Be Done on the Same Day as Other Tests?
- Contrast in a PET-CT Scan: When It Is Used and Why
- Eating and Drinking After Your PET-CT Scan
- How Long Does a PET-CT Scan Take?
- Is a PET-CT Scan Painful?
- Is a PET-CT Scanner Closed Like an MRI? Claustrophobia Explained
- The Tracer Injection: Does It Hurt?
- What Happens If the Scan Cannot Be Completed?
- What If You Cannot Lie Still or Have Tremors?
- What to Expect Immediately After the Scan
- Why Was My Scan Repeated or Extended on the Day?
- Why You Have to Wait an Hour After the Injection
- Your PET-CT Scan Day: What Happens, Step by Step
Diabetes & Blood Sugar for PET-CT
- A Diabetic Patient's PET-CT Day Plan
- Best Appointment Time for a Diabetic PET Scan
- Can Diabetics Take Their Tablets Before a PET Scan?
- Does Diabetes Change Your SUV Reading?
- Fasting Safely With Diabetes Before a Scan
- Insulin and PET-CT: Timing Rules
- Newly Diagnosed Diabetes Found Before a Scan
- PET-CT Scan With Diabetes: The Complete Preparation Guide
- PET-CT With Steroid-Induced High Sugars
- What Blood Sugar Level Is Needed for a PET-CT Scan?
- What Happens If Your Sugar Is High on the Day?
- What to Eat the Day Before if You Have Diabetes
Preparing for Your Scan
- A Printable PET-CT Preparation Card
- Can I Drink Water Before a PET-CT Scan?
- Can I Have a PET-CT Scan During My Period?
- Can I Take My Regular Medicines Before a PET-CT Scan?
- Can You Reschedule a PET-CT Scan?
- Cold Weather, Shivering and Brown Fat: Why You Are Asked to Stay Warm
- Fasting Before a PET-CT Scan: How Long and Why
- How to Prepare for a PET-CT Scan: The Complete Checklist
- Preparing a Very Elderly or Frail Person for a PET-CT
- Preparing a Wheelchair-Bound or Bedridden Patient
- Preparing for a PSMA, DOTATATE or FAPI PET-CT
- Should I Avoid Exercise Before a PET-CT Scan?
- Smoking, Alcohol and Caffeine Before a PET-CT Scan
- What Happens If You Break the Fast by Mistake?
- What to Carry to Your PET-CT Appointment
- What to Eat the Day Before a PET-CT Scan
- What to Wear to a PET-CT Scan
- Why Your Kidney Function Test Is Needed Before a PET-CT
Radiation Safety & After-Scan Precautions
- Are You Radioactive After a PET-CT Scan?
- Being Around Pregnant Women After a PET-CT Scan
- Can I Hold My Child or Grandchild After a PET-CT Scan?
- Can a PET-CT Scan Cause Cancer?
- Cumulative Radiation From Repeated Scans
- Do You Need Precautions After a PSMA or DOTATATE Scan?
- Do You Need Separate Utensils or a Separate Toilet After a PET-CT?
- How Long Does the Tracer Stay in Your Body?
- How Long Should You Avoid Close Contact After a PET-CT?
- How Many PET-CT Scans Are Safe in a Year?
- How Much Radiation Is in a PET-CT Scan?
- Is PET-CT Radiation Different From Radiotherapy?
- Is the Radiation From a PET-CT Scan Dangerous?
- PET-CT Radiation Compared With CT, X-Ray and Natural Background
- Radiation Safety at Home After Your Scan: A Family Checklist
- Radiation Safety for Staff and Attendants at the Centre
- Simple Steps to Clear the Tracer Faster
- Travelling Home After a PET-CT Scan: Public Transport and Airports
Your next step
Talk to an oncologist about your scan
Your PET-CT report read by a senior oncologist, explained in plain language, with a free 45-minute consultation.
Common questions
Frequently asked questions
Does a PET-CT with contrast cost more than one without?
Yes, contrast typically adds to the cost. The contrast agent itself has a cost, and the scan is more involved to perform. The difference varies across partner imaging centres and cannot be quoted as a fixed figure — ask the imaging centre for an indicative price before your appointment so you are not surprised on the day. When your oncologist has requested it, it is because the additional information changes what the scan can show, not an optional upgrade.
Will I feel anything when the contrast is injected?
Most people notice a sudden warmth spreading through the body and sometimes a metallic or salty taste in the mouth. These sensations are normal and pass within about a minute. Some people briefly feel as though they have passed urine — you have not, but the warm flush in the pelvic area produces that sensation. More significant reactions are uncommon. The radiology team is trained to watch for them and will ask you to stay briefly after the scan for this reason.
Can I have contrast if I have kidney problems?
Iodine-based contrast is processed by the kidneys, so kidney function matters. If your kidneys are not working well, contrast can place extra strain on them. The radiologist at the partner imaging centre will check a recent blood test result before contrast is given. If your kidneys are not able to handle it safely on that day, the scan will proceed without contrast or a different approach will be discussed. Always tell the team about any kidney condition before the scan begins.
Is the contrast injection the same as the radiotracer injection?
No. These are two completely different substances given for different reasons. The PET radiotracer — usually FDG, a radioactive glucose — is given well before scanning begins and is what the PET camera detects. The CT contrast is an iodine-based dye given just before or during the CT run. It does not appear on the PET images and plays no part in what the PET detects.
I take metformin for diabetes. Does that affect the contrast?
Yes, and it is important to tell the team before the scan. In certain circumstances, metformin and iodine-based contrast together can affect how the kidneys clear the medicine. The radiology team will give you specific instructions based on your kidney function results and their protocol — which may include pausing metformin for a period after the scan. Do not stop taking it before the scan without being told to. Follow the guidance given by the team at the imaging centre, not general advice.