Nuclear cardiology pathway · London
Myocardial perfusion scanning (MPI), nuclear cardiology with stress + rest imaging for coronary disease.
Myocardial perfusion imaging (MPI) uses Tc-99m sestamibi or Rb-82 PET to assess coronary blood flow at stress and rest. Quantifies inducible ischaemia and infarct — a mainstay for chest-pain evaluation and pre-op cardiac risk.
Why patients choose us
- 01
The right hands
We route you to a consultant nuclear cardiologist — the person reading your perfusion maps is the person who decides the next step.
- 02
Same-week answer
Stress and rest imaging, quantitative perfusion analysis and a written cardiology report typically completed inside a week.
- 03
Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Key facts
The six things worth knowing about myocardial perfusion scanning.
What the pathway is, what it can — and cannot — settle, and the numbers that drive management.
-
Definition
Nuclear cardiology stress + rest perfusion imaging that maps coronary blood flow to the heart muscle.
-
Tc-99m sestamibi SPECT or Rb-82 PET
Two established tracer options: Tc-99m sestamibi on SPECT, or rubidium-82 on cardiac PET for higher-resolution quantification.
-
Pharmacological or exercise stress
Adenosine or regadenoson vasodilator stress for patients who can’t exercise; treadmill or bicycle stress where feasible.
-
Quantifies ischaemic burden
Reports the percentage of left-ventricular myocardium showing inducible ischaemia — the number that drives management.
-
Complements CTCA and stress echo
Anatomy (CTCA) plus function (MPI) plus wall-motion (stress echo) — each answers a different question.
-
Reported by nuclear cardiology
A consultant nuclear cardiologist interprets perfusion, function and prognostic risk together.
The diagnostic pathway
From consultation to report — what happens, in order.
One clinician from first message to plan — typically inside a week.
- 01
Cardiology consultation
History, risk factors, ECG and pre-test probability review to confirm MPI is the right next test.
- 02
Withhold caffeine 24 hours
Caffeine and methylxanthines block adenosine receptors and will invalidate a vasodilator stress test.
- 03
IV cannula for tracer
A small forearm cannula is placed for injection of the radiotracer and, if needed, the vasodilator agent.
- 04
Stress phase (exercise or vasodilator)
Treadmill or bicycle exercise where possible; otherwise adenosine or regadenoson infusion with continuous ECG monitoring.
- 05
Rest phase imaging
A second acquisition after tracer redistribution at rest, for direct comparison against the stress dataset.
- 06
Perfusion maps generated
Polar maps and segmental scores are produced, with quantitative ischaemic burden and left-ventricular ejection fraction.
- 07
Cardiology report
A consultant nuclear cardiologist reports ischaemia, infarct, LV function and a prognostic risk score — with the concrete next step.
Typical end-to-end: 5–7 days. Urgent cases: same week.
What it shows
What myocardial perfusion imaging can — and cannot — settle.
MPI answers a specific question — how much of the left ventricle is under-perfused at stress, and what that means for risk and treatment.
-
Reversible ischaemia (inducible)
A stress defect that normalises at rest — the classic pattern of a flow-limiting coronary stenosis.
-
Fixed defect (infarct)
A perfusion defect present at both stress and rest — established scar or prior myocardial infarction.
-
Left-main pattern
A large ischaemic burden in a left-main distribution — a prognostically important finding.
-
Balanced ischaemia
Globally reduced flow reserve suggesting multi-vessel disease that can mask a focal defect.
-
LVEF measurement
Gated acquisition provides left-ventricular ejection fraction alongside the perfusion data.
-
Response to revascularisation
Serial imaging to assess perfusion improvement after PCI or CABG.
-
Prognostic risk score
Summed stress, rest and difference scores translate perfusion findings into a risk category.
-
Red flag: > 10% ischaemic burden — urgent invasive angiography
A large inducible ischaemic burden meets guideline thresholds for urgent invasive coronary angiography.
Next steps
Options after a myocardial perfusion scan.
Management is driven by ischaemic burden, symptoms and left-ventricular function together — not by any single number alone.
-
Optimal medical therapy
Anti-anginal, antiplatelet, statin and blood-pressure therapy tuned to symptoms and risk.
-
CTCA for anatomy
CT coronary angiography to complement functional data with a definitive anatomical map.
-
Invasive coronary angiography ± FFR
Cardiac catheterisation with fractional flow reserve where physiology-guided decision-making is needed.
-
PCI
Percutaneous coronary intervention — angioplasty and stenting for suitable lesions.
-
CABG
Coronary artery bypass grafting for left-main, three-vessel or complex disease.
-
Cardiac rehabilitation
Structured exercise, education and secondary prevention after an ischaemic event or revascularisation.
-
Cardiovascular risk optimisation
Lipids, blood pressure, glycaemic control, weight, smoking and activity — the levers that shift long-term risk.
-
Structured cardiology follow-up
Serial review to reassess symptoms, medication and — where indicated — repeat functional imaging.
Red flags
When an MPI finding needs urgent action.
Some findings on a perfusion scan need urgent invasive review rather than watchful follow-up. These are the ones we look for first.
-
Large ischaemic burden
A large inducible ischaemic burden warrants urgent invasive coronary angiography rather than watchful waiting.
-
Balanced multi-vessel ischaemia
A globally reduced flow reserve can look near-normal on perfusion mapping — the report has to look for it explicitly.
-
Post-MI LV aneurysm
A left-ventricular aneurysm on gated imaging changes both surgical and anticoagulation planning.
-
Reduced LVEF response
A drop in ejection fraction from rest to stress is an adverse prognostic sign, independent of perfusion.
-
Post-CABG graft failure
A new inducible defect in a previously bypassed territory raises the question of graft failure.
-
Cardiac amyloid on imaging
Suspicious appearances warrant onward cardiac MRI or dedicated PYP/DPD scintigraphy.
-
Anaemia affecting perfusion
Significant anaemia can globally reduce perfusion and complicate interpretation.
-
Uncontrolled arrhythmia
Ongoing AF or frequent ectopy degrades gated LVEF and can invalidate stress imaging.
-
Post-stent restenosis
A new defect in a stented territory raises the question of in-stent restenosis and warrants invasive review.
Reading your report
A perfusion report can look intimidating. It isn’t.
Whatever the finding, the report keeps to the same four parts.
A quiet reminder
The report is written for your doctor, not for you — and that’s normal.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and risk factors
Your details, the reason for the scan, and the cardiovascular risk factors that shape interpretation.
- 02 Technique
Tracer, stress agent and acquisition
Which radiotracer was used, the stress protocol (exercise or vasodilator), and any acquisition limitations.
- 03 Findings
Perfusion, function and burden
Segmental perfusion scores, ischaemic burden as a percentage of LV, gated LVEF and any transient ischaemic dilation.
- 04 Impression
The conclusion: read this first
Normal, low/intermediate/high risk, and the concrete next step — read this first.
Sources
The guidance that anchors this page.
Reviewed on 2026-07-30. Next scheduled review 2027-07-30.
Recognised by major UK insurers
Cover depends on your policy and clinic; we confirm with your insurer before booking.
Frequently asked
Everything we get asked about myocardial perfusion scanning.
Quick answers on tracers, caffeine, radiation, how MPI compares with CTCA and stress echo, and what an abnormal result actually means.
-
What is myocardial perfusion imaging (MPI)?
MPI is a nuclear cardiology test that maps blood flow to the heart muscle at stress and at rest. A small dose of a radiotracer (Tc-99m sestamibi for SPECT, or Rb-82 for cardiac PET) is given intravenously, and gamma-camera or PET images show which parts of the left ventricle are getting adequate flow — and which are not.
-
Why do I have to avoid caffeine for 24 hours before the scan?
Vasodilator stress agents like adenosine and regadenoson work through the same receptors that caffeine and other methylxanthines block. Even a single cup of coffee or tea in the preceding 24 hours can invalidate the stress test and force a repeat visit.
-
What is the difference between MPI, CTCA and stress echocardiography?
CTCA gives an anatomical map — where the coronary arteries are narrowed. MPI gives a functional map — whether that narrowing is actually restricting flow to heart muscle. Stress echocardiography looks at wall motion under stress. They answer different questions and are often complementary rather than interchangeable.
-
What does "ischaemic burden" mean?
Ischaemic burden is the percentage of the left ventricle that shows inducible ischaemia at stress. It is the single most useful number in an MPI report — a burden above 10% typically meets guideline thresholds for urgent invasive coronary angiography.
-
Is the radiation dose safe?
The radiation dose is real but small — typically 3–12 mSv depending on protocol, comparable to a year or two of natural background radiation. For a clinically indicated test the benefit substantially outweighs the risk, and Rb-82 PET protocols in particular now deliver very low doses.
-
What happens after an abnormal MPI?
The report drives the plan: a small, low-risk defect may be managed with optimal medical therapy and follow-up; a large ischaemic burden — or a high-risk feature such as transient ischaemic dilation or a reduced LVEF response — typically triggers invasive coronary angiography with a view to PCI or CABG.
Related
Looking for a different test?
-
Cardiac stress testing
Exercise or pharmacological stress with ECG and imaging correlates.
Learn more -
CT coronary angiography
Non-invasive anatomical map of the coronary arteries.
Learn more -
Cardiac MRI
Structure, function and tissue characterisation of the heart.
Learn more -
All tests
Browse every test and procedure we arrange.
Learn more -
Hypertension
Related condition guide.
Learn more -
Atrial Fibrillation
Related condition guide.
Learn more -
Coronary Angioplasty
Related treatment option.
Learn more -
Coronary Artery Disease Treatment
Related treatment option.
Learn more
In practice, in London
The London pathway for myocardial perfusion scanning
With myocardial perfusion scanning, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. The wait for myocardial perfusion scanning on the NHS depends heavily on where you live and how urgently the referral is graded. Central and West London private clinics can normally book within a week, with imaging or a procedure slot to follow shortly after. It’s worth being honest about the reason for going private: usually it’s time, not a fundamentally different test.
The mechanics are straightforward: a consultant appointment, any tests done at a nearby CQC-registered site, and a written report back within a few days. London’s density of private diagnostics — Marylebone, the City, Chelsea, Canary Wharf — means most patients can find something that fits around work without a cross-town trek. For myocardial perfusion scanning specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
There are a lot of consultants in London who can technically handle myocardial perfusion scanning. Fewer who do it week in, week out for the exact question you’re bringing. We spend most of our time working out which is which — and being straight when a different test or a different specialist would serve you better. Everything runs to CQC, GMC and Royal College standards; the choice is about fit, not floor.