A coronary calcium score or a CT coronary angiogram has reported a nodule on your lung. Nodules appear on around one in seven of these scans, most are small, and most are benign: in a study of 2,750 people, 87% of nodules larger than 6 mm were not cancer. A heart scan also images only the part of the lung that surrounds the heart, so it says little about the upper lobes either way. Dr Lawrence Okiror, Consultant Thoracic and Robotic Surgeon (GMC 6150382), reviews the images and sets out what, if anything, should happen next. Appointments at London Bridge Hospital and The Lister Hospital Chelsea within 2–3 days, including video consultations. Self-referrals welcome.
Last reviewed: October 2026 · Dr Lawrence Okiror FRCS(CTh) FRCSEd(CTh) · GMC 6150382
Nodules were reported on 13.9% of 2,479 CT coronary angiograms. Nearly three-quarters were under 6 mm, the size below which UK guidance needs no follow-up at all.
Six in ten of those nodules were in people who had never smoked. Of nodules over 6 mm found alongside calcium scoring, 87% proved not to be cancer.
A cardiac CT covers the middle and lower chest. The upper lobes, where lung cancer most often arises, are largely outside the picture. A clear heart scan is not a lung check.
Because the lungs surround the heart, and any CT of the heart passes through lung on the way in. A calcium score and a CT coronary angiogram are set up to look at the coronary arteries. The lung that sits around the heart comes into view whether or not anyone intended to look at it, and a radiologist who sees a nodule there is obliged to describe it. The nodule was imaged incidentally and it is reported incidentally. Nothing about the way it was found tells you what it is.
Two things follow from that. The first is that the report was written by someone looking at the heart, on a scan reconstructed for the heart, and the lung has usually been described rather than assessed. The second is that what was imaged and what was reported are different things. A calcium-score scan is often acquired over more of the chest than the final heart images show, and a report that mentions no lung finding may simply not have looked.
What follows is how common these nodules are, how often they matter, what the field of view of a cardiac scan leaves out, and what the next step is by size. For the wider picture of findings on health-check imaging across the chest, see a scan or blood test has flagged something in your chest.
Often enough that it is one of the commonest reasons people arrive at this clinic with a report in hand. Two large studies put numbers on it.
The word nodule is a description of a shape on a scan, and the possibilities it covers are set out on the what is a lung nodule page. The ones a heart scan reports are the same ones any chest CT reports: old infection that has left a scar, a small lymph node inside the lung, a benign growth called a hamartoma, and, in a minority, an early cancer. The features that separate them are size, outline, density and behaviour over time, and none of those is visible in the word on the report.
No, and this is the point that heart-scan reports do not make. A calcium score is reconstructed to cover the heart. The images run from just above the heart to just below it, which takes in the middle and lower chest and leaves most of the upper lobes out. A CT coronary angiogram is acquired over a similar range, and the reconstruction sent to the reporting radiologist is often narrower still.
In the study that added a full-chest scan to 2,750 calcium scores, 12 of the 32 lung cancers found were outside the cardiac field of view. Those 12 people would have left with a normal heart scan and a cancer that no one had imaged.
Lung cancer arises in the upper lobes more often than anywhere else. The part of the lung a heart scan sees best is the part where cancer is least common, and the part it leaves out is the part where cancer is most common.
That is not an argument for buying another scan. Whether the upper lungs should be looked at depends on whether there is a reason to look: age, smoking history, occupational or asbestos exposure, a family history of lung cancer, or symptoms. Where there is such a reason, the right test is a dedicated low-dose CT of the chest, which images the whole lung and is the scan the NHS uses for lung cancer screening. Where there is no such reason, a further scan is more likely to produce another incidental finding than an answer. Who qualifies for screening, and who is left out by the criteria, is set out on the lung screening gap page.
The same limitation runs the other way. A nodule reported at the very edge of a heart scan has often been imaged only in part, and measuring it properly, or deciding what it is, may need one dedicated CT of the chest before anything else is decided. That is a single targeted study aimed at a specific question, and it is a different thing from repeating a survey scan.
Size first, then appearance, then change over time, read against your own history. UK guidance from the British Thoracic Society sets the intervals, and they are the same for a nodule found on a heart scan as for one found any other way. In plain terms, for a solid nodule in someone with no previous cancer:
| Size on the scan | What usually follows |
|---|---|
| Under 5 mm | Nothing further. The risk of cancer is too low to justify any follow-up scan. |
| 5 to 6 mm | One repeat CT at a year. If unchanged, discharge. |
| 6 to 8 mm | A repeat CT at three months, measured by volume where the scanner allows it, then one at a year if it has not grown. Then discharge. |
| 8 mm and above, or any growth | A risk score built from the nodule's features and your history. Where the score is high enough, a PET scan, and where that is positive, a biopsy. Where it is low, surveillance as above. |
Ground-glass and part-solid nodules follow a different, slower schedule, because they behave differently; that is set out on the ground-glass nodule page. A nodule that was already present and unchanged on any earlier chest scan you have had — for a chest infection, an accident, a previous heart check — is usually settled by that comparison alone, which is why earlier imaging is the most useful thing you can bring.
Whatever the plan, it has a stated interval and a stated end point. Surveillance means a defined number of scans over a defined period, after which the nodule is discharged. An open-ended arrangement to keep scanning is not surveillance, and it is not offered.
Heart-scan reports describe the lungs in a handful of stock phrases, and most of them are written for the cardiologist rather than for you. These are the ones that cause the most worry, with what each one means.
Reports that list “several” or “multiple” nodules of 2 to 4 mm alarm people more than a single nodule does, and they should not. A scatter of tiny nodules is the usual footprint of a past chest infection, and the more of them there are, the more that explanation fits. Guidance manages multiple nodules by the largest one: if the largest is under 5 mm, nothing further is needed; if it is larger, that nodule sets the interval and the others are simply noted on the same scan.
The size table above is written for people with no history of cancer, and the Fleischner guidance says so in its first line. If you have been treated for a cancer before, breast cancer, bowel cancer or any other, a new nodule on a heart scan is a different question. It is still most often benign, but the other possibilities are a deposit from the earlier cancer or a new and separate lung cancer, and those are treated in entirely different ways. The nodule should be reviewed against your cancer history and your previous scans rather than filed under the standard intervals, and the team that treated your cancer should know about it.
Cancer spread to the lungs — what it means and when surgery helps →
Breast cancer that has spread to the chest →
A calcium score occasionally reports a nodule of 10, 15 or 20 mm. That is not a surveillance finding; it needs a proper CT of the chest and a specialist review within days, and it is the one situation on this page where waiting for a routine follow-up is the wrong plan. Most nodules of this size are still benign. If you have had a blood clot in the lung, the damage a clot leaves is usually a wedge against the outer surface of the lung that shrinks over months, and a rounded nodule is assessed as a nodule rather than assumed to be the clot.
The usual outcome of sending me a heart-scan report with a lung nodule on it is reassurance, or surveillance with a defined interval. A targeted CT of the chest is arranged where the heart scan has not imaged enough of the nodule, or where there is a reason to look at the rest of the lung. Biopsy and surgery are for the few whose nodule justifies them.
The consultation is a review of the images themselves rather than the report. The heart-scan images are opened on screen, the full acquired range is examined rather than the reconstruction sent to the cardiologist, and any previous chest imaging is compared alongside. Bring the images — a disc, a download link or the access details from the clinic that performed the scan — and any earlier chest scan you have had for any reason.
Where tissue is needed, robotic navigational bronchoscopy at London Bridge Hospital reaches nodules in the outer lung without an incision, as a day case. Where surgery is the right answer, it is lung-sparing and robotic wherever the oncology allows, and it is preceded by discussion at the chest multidisciplinary team meeting. As a lung nodule specialist in London I see patients from across the UK and abroad; where you live at a distance, a targeted CT can be arranged locally and reviewed by video.
Your patient can be referred directly with the report, the images and one line of history. A clinic letter goes back to you and to the GP within 2 working days, and an outcome note follows when the question is closed. The referral route, the thresholds and what comes back are set out on the abnormal chest imaging referral page.
The statements on this page are written without technical vocabulary. The underlying figures are set out here in full for anyone who wants them.
Questions people ask after a calcium score, a CT coronary angiogram or another cardiac scan has reported a nodule on the lung.
Book a Consultation →Or call Jo Mitchelson:
020 7952 2882
Self-referrals welcome. Appointments at London Bridge Hospital and The Lister Hospital Chelsea within 2–3 days, including video consultations, with outpatient clinics at Canary Wharf and the City of London. Bring the images and the report, and any earlier chest scan.
Jo Mitchelson, PA · 020 7952 2882 · pa@lungsurgeon.co.uk
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