Haemoptysis

ACR AC Hemoptysis; CIRSE bronchial artery embolisation standards

Imaging has to answer two questions at once: what is bleeding, and where is the artery that supplies it. Both need intravenous contrast, and neither is answered by a normal chest radiograph — which is why a normal radiograph in a smoker with haemoptysis is a reason to scan, not a reason to stop.

Frank blood or blood-streaked sputum, ranging from a single episode in a well outpatient to life-threatening bleeding needing airway protection and embolisation.

Referenced decision support — confirm against your local protocol.

Decision support, not a directive. Protocols and timings shown are typical published ones — your local protocol takes precedence, and the vetting radiologist decides.

The request in front of you

Everything is optional. Leave a field alone and the answer assumes nothing — the verdict updates as you go.

Study requested

What the referrer actually asked for. It is evidence of intent, not a constraint on the right answer.

Contrast as written

What the request form says, not what it should say.

Age

Pick a band, or type an exact age if it matters.

years

Pregnancy status

Haemodynamic state

The fact that lets a pathway waive its own requirements. A crashing patient does not wait for a score.

Where is the patient?

Some pathways change in the emergency department — an acutely threatened limb is not an elective work-up.

Renal risk factors

The question a vetter can actually answer from the request. An explicit “none known” is a real answer, and it removes checks rather than deferring them.

Previous contrast reaction

The pathway — tap anything already done

Marking a study complete moves the answer on. A patient arrives partway through a pathway far more often than at the start of one.

Accept as requested

CT Chest — Contrast-Enhanced (Venous Phase)

CT Chest

What we'd amend, and why

The causes that matter are central and endobronchial — tumour, bronchiectasis, aspergilloma, arteriovenous malformation — and all of them are soft-tissue or vascular findings that need contrast to be characterised and to be separated from the blood that has been aspirated into surrounding lung. A radiograph localises the side at best; it cannot show an endobronchial tumour, and roughly a third of patients with a malignant cause have a normal or non-localising film. The scan also defines the aspirated blood, which is what tells the bronchoscopist which lung to protect.

Nothing needs resolving before this goes ahead. Routine checks below are owned downstream.

How was this decided?

pathwayadult — Adults — haemoptysis without active large-volume bleeding
rulerule-contrast-reaction-premed — Prior contrast reaction and elective premedication; checked by Nurse before the scan
rulerule-metformin — Metformin and iodinated contrast; checked by Radiographer at the scanner
rulerule-paeds-dose — Child-sized technique and contrast dose; checked by Radiographer at the scanner
rulerule-pregnancy-ionising — Pregnancy status before an ionising exposure; checked by Radiographer at the scanner
rulerule-renal-iodinated — Kidney function and intravenous iodinated contrast; checked by Radiographer at the scanner
rulerule-iv-access — Intravenous access adequate for the planned injection; checked by Radiographer at the scanner

Decision support only. Local protocol takes precedence.

Handled at the scanner(4)nothing for you to do

Settled and owned downstream. Each returns to a radiologist only on the stated trigger.

Metformin and iodinated contrast
Confirm whether the patient takes metformin or a metformin-containing combination, and if so whether ACR Category II applies (eGFR below 30, known or suspected AKI, or an arterial catheter study likely to cause renal embolisation). If Category I — that is, no AKI and eGFR at or above 30 — no action of any kind is needed.
Radiographer at the scannerAt the scanner
Flags back if: The patient takes metformin AND meets ACR Category II — eGFR below 30 mL/min/1.73 m2, known or suspected acute kidney injury, or an arterial catheter procedure with likely renal arterial embolisation. Metformin plus a normal or mildly reduced eGFR is explicitly NOT a flag-back: there is no need to stop metformin before or after intravenous iodinated contrast in Category I patients, and no need to re-check creatinine afterwards.
Child-sized technique and contrast dose
Confirm that a size- or weight-based protocol is selected — child-sized kV and mAs against size-based diagnostic reference ranges — and that contrast volume is calculated by weight rather than taken from an adult default. Weight-based iodinated contrast volumes of roughly 1.5–2.0 mL/kg are widely used in paediatric CT.
Radiographer at the scannerAt the scanner
Flags back if: No paediatric or size-based protocol exists on the scanner for the requested examination, or the requested coverage or number of phases exceeds what the clinical question needs — for example a multiphase study where a single phase answers it, or whole-body coverage for a focal question.
Pregnancy status before an ionising exposure
Make the pregnancy enquiry immediately before the exposure and record the answer. In the UK this is a statutory operator duty discharged at the time of exposure under the employer’s written procedures required by IR(ME)R 2017 — it is not something the vetting radiologist can perform or pre-empt, and a request is complete without it.
Radiographer at the scannerAt the scanner
Flags back if: The patient states that she is, or may be, pregnant AND the uterus is in or near the primary beam. The exposure is then paused for re-justification by the IR(ME)R practitioner before it proceeds.
Intravenous access adequate for the planned injection
Site and test a cannula that supports the protocol flow rate, preferring an antecubital or large forearm vein, and observe the injection for extravasation. A 20-gauge or larger cannula is preferred for flow rates of 3 mL/s or more.
Radiographer at the scannerAt the scanner
Flags back if: No cannula can be sited that supports the protocol flow rate — for example only a 22-gauge hand or foot cannula for a CT angiogram needing 4–5 mL/s; or the only available access is a central line or port that is not labelled power-injectable; or an extravasation occurs.

Pathways

Big forks are separate pathways; the first whose conditions match is the one used.

Acute large-volume haemoptysis — emergency, inpatient or unstable presentation

Role	Study & protocol	Why this answers the question
First line	CT Chest CT Chest — Bronchial Artery CTA (pre-embolisation) usually appropriate	A patient bleeding into their airway is on an interventional pathway, and what the interventional radiologist needs from CT is a road map of the vessels they are about to catheterise. That is an arterial acquisition, bolus-tracked in the descending thoracic aorta: the bronchial arteries are one to two millimetres across, and on a portal-venous chest CT they are not opacified at all — the mediastinal veins are, which is why a routine contrast-enhanced chest CT can look entirely adequate and answer none of the question. Coverage is the second half of the protocol. Bronchial artery origins are variable and frequently ectopic, and a substantial minority of massive haemoptysis is fed by non-bronchial systemic vessels — inferior phrenic, intercostal, internal mammary, subclavian and axillary branches — which lie outside a standard chest field of view. Recurrent bleeding after embolisation is most often from a feeder that was never imaged. The same study identifies a bronchial artery giving rise to an anterior spinal branch, which decides whether that vessel can be embolised at all, and separates the minority with a pulmonary arterial source such as a Rasmussen aneurysm, which is a different procedure by a different route. One sequencing point outranks all of it. Massive haemoptysis kills by asphyxiation rather than by exsanguination, so the airway comes before the scanner: the patient is positioned with the bleeding side down to protect the good lung, and a patient whose airway is not secure should not leave a resuscitation area for a CT table where nobody can suction them. Where the side is known and the bleeding is uncontrolled, the anaesthetic and bronchoscopic decisions run in parallel with the scan, not behind it.
Reasonable alternative	Chest radiograph Chest radiograph — PA (± lateral)	The immediate bedside study in active bleeding: it lateralises, shows a large collapse or a mass, and takes seconds in a patient who cannot yet be moved to a scanner. Its role is triage rather than diagnosis, and it must not be used to close the question or to select the vessel.
Problem solving	CT Chest CT Chest — Contrast-Enhanced (Venous Phase)	Where the bleeding has settled, embolisation is not in prospect and the remaining question is the cause rather than the vessel, the venous-phase study is the better acquisition: a central endobronchial tumour and mediastinal nodal disease are soft-tissue discriminations that an arterial-timed scan makes less well. Say so on the request, because the two protocols look identical from the ward.

This fork is entered on the care setting, which is the closest proxy the request carries for the volume of bleeding. It is a starting assumption: an admitted patient with a few streaks of blood and a suspected tumour should be protocolled from the default pathway, and a well-looking outpatient describing a cupful of blood belongs here. Volume and the embolisation question, stated on the request, override the setting.

Adults — haemoptysis without active large-volume bleeding

Matches your inputsDefault

Role	Study & protocol	Why this answers the question
First line	CT Chest CT Chest — Contrast-Enhanced (Venous Phase) usually appropriate	The causes that matter are central and endobronchial — tumour, bronchiectasis, aspergilloma, arteriovenous malformation — and all of them are soft-tissue or vascular findings that need contrast to be characterised and to be separated from the blood that has been aspirated into surrounding lung. A radiograph localises the side at best; it cannot show an endobronchial tumour, and roughly a third of patients with a malignant cause have a normal or non-localising film. The scan also defines the aspirated blood, which is what tells the bronchoscopist which lung to protect.
Reasonable alternative	Chest radiograph Chest radiograph — PA (± lateral)	The immediate bedside study in active bleeding: it lateralises, shows a large collapse or a mass, and takes seconds in a patient who cannot yet be moved to a scanner. Its role is triage rather than diagnosis, and it must not be used to close the question.
Second line	CT Chest CT Chest — Bronchial Artery CTA (pre-embolisation)	When embolisation is planned — recurrent bleeding from established bronchiectasis, an aspergilloma or post-tuberculous lung, even in an outpatient — the operator needs an arterial-phase map of the descending thoracic aorta and its branches: hypertrophied bronchial arteries, anomalous and ectopic origins, and the non-bronchial systemic supply from intercostal, internal mammary, inferior phrenic and subclavian branches that accounts for many failed and recurrent embolisations. That is a different protocol on the same scanner: bolus-tracked arterial timing, coverage extended above the arch and below the diaphragm, and oblique maximum intensity projections along the aorta to find the origins. The venous-phase chest study will show the underlying disease and none of this.

Pitfalls

Reassurance from a normal chest radiograph. In a smoker over 40 with haemoptysis, a normal film does not exclude a central endobronchial tumour and should escalate rather than terminate the pathway.
Sending a patient to embolisation on a routine portal-venous chest CT. The bronchial arteries are not opacified at that delay and the coverage stops short of the inferior phrenic and internal mammary origins, so the study answers the cause and not the vessel — and the operator discovers this on the angiography table.
Accepting a CT pulmonary angiogram as the study for haemoptysis. Pulmonary arterial timing washes the systemic arteries out and misses the bronchial supply, which is the vessel that bleeds in the great majority of cases.
Requesting an unenhanced CT and reporting the cause as unidentified.
Failing to say which side is bleeding when it is known — it changes the bronchoscopic and interventional approach immediately.
Attributing haemoptysis to anticoagulation alone. Anticoagulation unmasks a lesion far more often than it causes bleeding on its own.
Sending a patient with an unprotected airway to the scanner. Massive haemoptysis kills by asphyxiation, not by blood loss, and a CT table is the worst place to lose an airway — positioning bleeding-side-down, suction and the anaesthetic decision come first, and the scan runs alongside them rather than in front of them.
Reading a normal-looking bronchial arterial tree as excluding a treatable source. A substantial minority of massive bleeding is fed by non-bronchial systemic vessels or, less often, by the pulmonary arteries, and each is found only if the coverage and the phase were chosen to look for it.

Priors — what to pull first

Check for previous imaging of a known cause — recurrent bleeding from a long-standing aspergilloma or from established bronchiectasis is a different pathway from first-episode haemoptysis in a smoker.
If the patient has been embolised before, retrieve the procedural imaging: recurrence is usually from a vessel that was not treated rather than recanalisation of the one that was.

What makes a good request

A good request states the volume and duration of bleeding, the smoking history, whether there is known bronchiectasis, tuberculosis, aspergilloma or malignancy, and whether the patient is anticoagulated.
Volume changes the destination as much as the protocol. Large-volume bleeding is an interventional radiology pathway, and the scan exists mainly to map hypertrophied bronchial and non-bronchial systemic arteries before embolisation — so tell the vetter if embolisation is being considered, because it selects a different acquisition on the same scanner.
The two acquisitions are not interchangeable. The venous-phase chest study answers "what is the cause"; the bronchial artery CT angiogram answers "which vessel does the interventional radiologist catheterise", and only the second is arterial-timed with the coverage extended to find non-bronchial systemic feeders.

Scoring this once it is done

The classification and risk tools this question ends in.

eGFR (CKD-EPI 2021 Creatinine)Lung Cancer TNM Staging (9th Edition)Lung-RADS v2022 (Screening LDCT)RECIST 1.1 Tumor Response PERCIST 1.0 PET Response Bhalla / Brasfield Score (CF)

How these studies are acquired

Contrast, phases and timing for every study on the pathways above.

CT Chest — Bronchial Artery CTA (pre-embolisation)Chest radiograph — PA (± lateral)CT Chest — Contrast-Enhanced (Venous Phase)

Confirm locally

CT Chest — Contrast-Enhanced (Venous Phase): timings are typical — confirm against local protocol.
Timings, contrast volumes and rates above are typical published values. Your department's protocol, scanner and patient population decide the actual numbers.
Safety thresholds and premedication policy follow local policy where it differs from the cited guidance.

References

Implemented from the cited published sources. Educational and workflow support only; confirm against current guidelines and local policy before clinical use.