— 01 · At a Glance
What is a brain PET scan?
★ In one paragraph
A brain PET scan is a PET/CT test that shows how the brain is working rather than only its structure. A small injected radiotracer maps a chosen target: FDG maps glucose metabolism (for dementia, epilepsy and tumours); amyloid and tau tracers detect the proteins of Alzheimer's disease; and F-DOPA or amino-acid tracers assess movement disorders and tumours. The tracer is chosen for the clinical question, and the scan is read alongside an MRI.
Where an MRI or CT shows the brain's anatomy, a brain PET adds its function — a difference explained in PET scan vs CT scan. That functional information is what lets PET distinguish one dementia from another, find a seizure focus that looks normal on MRI, or tell active tumour from treatment change.
At Theranostic Physicians, brain PET is performed in the Department of Nuclear Medicine at Fortis Memorial Research Institute (FMRI), Sector 44, Gurugram, with interpretation led by Dr. Ishita B. Sen and Dr. Dharmender Malik, alongside your neurologist.
— 02 · Machine & Reader
The scan is only as good as who reads it.
Brain PET depends on a good machine, a good reader, and the right preparation — the brain's metabolism shifts with what you see, hear and think during tracer uptake, so a quiet, controlled environment is part of a good study.
- The institution. Scans are performed at Fortis Memorial Research Institute, Sector 44, Gurugram — a leading tertiary hospital with a dedicated Department of Nuclear Medicine and modern PET/CT.
- The reader. Every study is interpreted by Dr. Ishita B. Sen and Dr. Dharmender Malik, read with the MRI and the clinical picture. Recognising the metabolic signature of a dementia, or separating a true seizure focus from normal variation, is a matter of experience.
A scan is only ever as reliable as the equipment that acquires it and the physician who reads it. We hold both to the same standard.
— 03 · The Tracers
The brain PET tracers.
“Brain PET” is a family of studies. Same scanner, different tracers, different questions.
| Tracer |
What it maps |
Main use |
|
FDG
|
Glucose metabolism |
Dementia pattern, epilepsy focus, tumours |
|
Amyloid
|
Amyloid plaques |
Supporting an Alzheimer's diagnosis |
|
Tau
|
Tau tangles |
Alzheimer's-type tau burden |
|
F-DOPA / amino-acid
|
Dopamine pathway / amino-acid uptake |
Movement disorders · brain tumours |
FDG is the workhorse and the most widely available. The amyloid, tau, F-DOPA and amino-acid tracers are specialised — availability varies by centre, so the right one is confirmed when the scan is arranged.
— 04 · Indications
Who needs a brain PET scan?
A brain PET is requested by your neurologist, neurosurgeon or psychiatrist for specific questions:
- Memory loss and suspected dementia. To distinguish Alzheimer's from frontotemporal and other dementias by their metabolic pattern, and — with amyloid or tau tracers — to detect the proteins of Alzheimer's.
- Epilepsy surgery planning. To localise the seizure focus, which often shows reduced metabolism between seizures, when surgery is being considered.
- Brain tumours. To help grade a tumour and, especially with amino-acid tracers, to tell active or recurrent tumour from treatment-related change after surgery or radiotherapy.
- Movement disorders. To assess the dopamine pathway in Parkinsonian conditions.
★ PET and MRI together
Brain PET almost always complements an MRI rather than replacing it. MRI shows structure in fine detail and remains first-line — including for brain metastases, which an FDG scan can miss because the normal brain is so metabolically active. PET adds the functional layer the MRI cannot.
— 05 · The Visit
What to expect on the day.
Plan for about one and a half to two hours. For an FDG brain PET the preparation has one feature people do not expect — the need to keep the brain quiet during uptake.
01
Before you arrive
For an FDG scan, fast for a few hours and avoid sugary drinks. Diabetic patients need blood-sugar planning — tell the team in advance. Specialised tracers have their own instructions.
02
Injection
A small intravenous injection of the tracer — painless beyond the needle prick.
03
Quiet uptake
You rest in a dimly lit, quiet room for the uptake period — about 30 to 60 minutes for FDG — without talking, reading or using a phone, because mental and sensory activity changes brain metabolism and the images.
04
The scan & the read
A short scan of about 15 to 30 minutes with your head supported. Dr. Sen and Dr. Malik interpret the images with your MRI and clinical details.
Out-of-town and international patients are helped with scheduling and the preparation.
— 06 · Accuracy
What a brain PET shows — and its limits.
- Dementia. FDG patterns help separate Alzheimer's from other dementias; amyloid and tau PET add direct evidence of the underlying proteins. PET is one input, read with cognitive testing and MRI — not a stand-alone diagnosis.
- Epilepsy. FDG can reveal a seizure focus that looks normal on MRI, helping plan surgery.
- Tumours. Amino-acid PET is generally better than FDG for outlining a tumour and for telling recurrence from radiation change, because the normal brain takes up so much FDG.
- Its limits. The brain's high background limits FDG for small lesions and for brain metastases, where MRI leads; and a positive amyloid scan shows plaques, which become common with age, so it must be read in context.
— 07 · Pricing
Cost of a brain PET scan in India.
A brain PET scan is billed by Fortis Memorial Research Institute — the same hospital counter price for everyone, with no commission added for booking through our team. The price depends on the tracer used.
| Scan |
Cost |
Includes |
|
Brain PET/CT (by tracer)
|
₹ [ ADD PRICE ] |
Tracer + brain PET/CT + expert report |
— 08 · Safety
Is a brain PET scan safe?
Yes — a brain PET scan is a safe, non-invasive test apart from a single small injection.
- The tracer is given in a microdose; reactions are rare.
- The radiation dose is low to moderate, comparable to other diagnostic PET studies, and decays quickly.
- Drink fluids afterwards to help clear the tracer.
- Tell the team if there is any possibility of pregnancy or if you are breastfeeding, and (for FDG) if you are diabetic.
— 09 · Booking
Book a brain PET scan.
Brain PET is performed at the Department of Nuclear Medicine, Fortis Memorial Research Institute, Sector 44, Gurugram — the single centre where we deliver scans — with interpretation led by Dr. Ishita B. Sen and Dr. Dharmender Malik, alongside your neurologist. Because the right tracer depends on the question, the first step is a short conversation to confirm which brain PET applies and its availability.
★ Referrals welcome
We accept and welcome referrals from your treating physician — neurologist, neurosurgeon, psychiatrist or family doctor. If you are a clinician referring a patient, contact us directly and we will coordinate scheduling and ensure the report reaches you. Patients may also enquire directly; we always share the final report with your treating doctor.
★ How to book
Message the team on WhatsApp +91 8700 668431 or email info@nuclearmedicinetherapy.in with your name, city, your neurologist's referral if you have one, and the question being asked (memory, epilepsy, tumour or movement disorder). We confirm which tracer applies, its availability, the preparation and a price quote. Out-of-town and international patients are helped with logistics.
Already have a brain PET from another centre? Request an independent expert opinion through our Second Read service.
Frequently asked questions.
What is a brain PET scan?
A brain PET scan is a PET/CT test that shows how the brain is working rather than only its structure. A small injected tracer maps a chosen target: FDG for glucose metabolism (dementia, epilepsy, tumours); amyloid and tau for the proteins of Alzheimer's; and F-DOPA or amino-acid tracers for movement disorders and tumours. It is read alongside an MRI.
What is a brain PET scan used for?
To help diagnose and distinguish dementias by their pattern of brain metabolism, to localise the seizure focus before epilepsy surgery, to assess brain tumours and tell active tumour from treatment change, and to evaluate Parkinsonian movement disorders. It is usually used alongside an MRI.
Can a PET scan detect Alzheimer's?
PET can support an Alzheimer's diagnosis. An FDG brain PET shows a characteristic pattern of reduced metabolism that helps separate Alzheimer's from other dementias; an amyloid PET detects amyloid plaques and a tau PET detects tau tangles. PET is one part of the assessment, read with the clinical picture, cognitive testing and MRI — not a stand-alone diagnosis.
How do I prepare?
For an FDG brain PET, fast for a few hours and avoid sugary drinks (diabetic patients need blood-sugar planning). Importantly, during uptake you rest quietly in a dimly lit room without talking, reading or using a phone, because mental and sensory activity changes brain metabolism. Specialised tracers have their own instructions, given when booking.
How long does it take?
About one and a half to two hours. After the injection there is a quiet uptake period — roughly 30 to 60 minutes for FDG — then the scan itself, about 15 to 30 minutes, with your head supported.
How much does a brain PET scan cost in India?
Is a brain PET scan safe?
Yes. The tracer is given in a tiny amount and reactions are rare; the radiation dose is low to moderate and decays quickly. Drink fluids afterwards. Tell the team about any possibility of pregnancy or breastfeeding, and (for FDG) if you are diabetic.
Is a PET or an MRI better for the brain?
They answer different questions and are usually complementary. MRI shows structure in fine detail and is first-line for most brain problems, including brain metastases. A brain PET shows function — metabolism or a specific protein — which adds information an MRI cannot, such as a dementia's metabolic pattern or a seizure focus. Your specialist chooses based on the question. See PET vs CT for the wider idea.
Where can I get a brain PET scan in Gurgaon?
Brain PET is performed at the Department of Nuclear Medicine, Fortis Memorial Research Institute, Sector 44, Gurugram, interpreted by Dr. Ishita B. Sen and Dr. Dharmender Malik alongside your neurologist. Because the right tracer depends on the question, contact the team on WhatsApp +91 8700 668431 to confirm which applies and its availability. Referrals welcome.
Written & Medically Reviewed By
Dr. Ishita B. Sen
MBBS · DRM · DNB (Nuclear Medicine) · 30+ years in nuclear medicine
Director and Head, Department of Nuclear Medicine and Molecular Imaging, Fortis Memorial Research Institute. Visiting fellowships at Memorial Sloan Kettering Cancer Center, New York and University of Marburg, Germany. Past President, Association of Nuclear Medicine Physicians of India.
FellowshipsMSK New York · Marburg
Past PresidentANMPI
SpecialityPET/CT & Molecular Imaging
Full profile
References & citations
- Nobili F, Arbizu J, Bouwman F, et al. EANM-EAN recommendations for the use of brain 18F-FDG PET in neurodegenerative cognitive impairment and dementia. European Journal of Nuclear Medicine and Molecular Imaging, 2018;45(9):1201–1212.
- Guedj E, Varrone A, Boellaard R, et al. EANM procedure guidelines for brain PET imaging using 18F-FDG, version 3. European Journal of Nuclear Medicine and Molecular Imaging, 2022;49(2):632–651.
- Johnson KA, Minoshima S, Bohnen NI, et al. Appropriate use criteria for amyloid PET. Journal of Nuclear Medicine / Alzheimer's & Dementia, 2013.
- Law I, Albert NL, Arbizu J, et al. Joint EANM/EANO/RANO practice guidelines for amino-acid PET imaging of gliomas. European Journal of Nuclear Medicine and Molecular Imaging, 2019;46(3):540–557.