CT Chest — Contrast-Enhanced (Venous Phase)

Lung apices to below the costophrenic angles, including the adrenal glands when staging.

Typical, not policy

Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.

When to use it

Staging or restaging of known thoracic or extrathoracic malignancy, including nodal assessment.
Characterisation of a mediastinal, hilar, pleural or chest wall mass.
Suspected empyema or complicated parapneumonic effusion, where pleural enhancement is the discriminator.
Assessment of a lung lesion where vascular relationships or chest wall invasion matter.

Technique

A delay of roughly 60-70 s from the start of injection is the conventional venous-phase timing for thoracic soft tissue and node assessment.
Where the chest and abdomen are both being staged, a single acquisition at around 60 s has been shown to serve both and reduces perivenous streak compared with two separate passes; sources differ on whether the chest is better served by a slightly earlier delay when the primary question is vascular.
Adrenal coverage is standard in oncological staging and costs nothing extra.

Where it goes wrong

An arterial-timed acquisition under-shows nodal and pleural enhancement and is not a substitute for venous-phase staging.
Failure to breath-hold produces basal motion that mimics ground-glass and consolidation.
Dense contrast in the brachiocephalic vein streaks across the superior mediastinum; injecting on the right and using a saline chaser mitigates it.
Requesting this protocol when the question is pulmonary embolism produces a study that is timed wrong for the pulmonary arteries.

Clinical questions that reach this study

Suspected pancreatic mass or painless obstructive jaundice Suspected cholangiocarcinoma Colorectal cancer — staging Incidental pulmonary nodule — characterisation and follow-up Known or suspected lung cancer — staging Suspected pneumonia and non-resolving consolidation Suspected empyema or complicated parapneumonic effusion Undiagnosed unilateral pleural effusion Suspected interstitial lung disease Suspected bronchiectasis Haemoptysis Suspected pneumothorax Suspected superior vena cava obstruction Staging or completion CT in a known solid tumour Liver assessment in a hypervascular primary Response assessment on systemic therapy Suspected or newly diagnosed lymphoma Metastatic disease with no identified primary Head and neck cancer — staging and post-treatment surveillance Indeterminate renal mass or suspected renal cell carcinoma Suspected phaeochromocytoma or paraganglioma Bladder cancer — pretreatment staging Acute scrotum and scrotal mass Suspected ovarian cancer or indeterminate adnexal mass

Contrast

Iodinated, intravenous

Typically 60-100 mL of non-ionic iodinated contrast at around 2-3 mL/s with a saline chaser.

Acquisition

Breathing: Single full inspiratory breath-hold.
Reconstruction: Thin axial reconstructions in both a soft-tissue and a high-frequency lung kernel, with coronal and sagittal reformats; reviewed on separate mediastinal and lung windows.
Preparation: Full inspiratory breath-hold, practised before the acquisition. Arms above the head; arms down doubles streak artefact through the upper thorax.

Phases

Each phase is authored once and shared across every protocol that uses it, so the physiology below is the same wherever you meet it.

Systemic venous (soft-tissue) phaseTypically ~45–90 s after the start of injection, with most published soft-tissue protocols sitting at ~60–80 s. Region-specific: reported neck delays span roughly 50–90 s, and routine contrast-enhanced chest work is conventionally ~60 s. Confirm locally.
Arteries and veins have equalised, and soft tissue outside the liver is at or near peak interstitial enhancement. The transferable principle is that away from the liver the purpose of a venous acquisition has nothing to do with portal delivery: it is that (a) every vessel is now uniformly dense, so a vessel stops being mistaken for a node or a mass, and (b) contrast has had time to leak into the expanded interstitium of inflamed or neoplastic tissue, which is what makes an abscess wall, a necrotic node, a mucosal tumour or a phlegmon declare itself against normal tissue. This is therefore the general-purpose soft-tissue phase for neck, chest, extremities and superficial structures. It is deliberately NOT called portal venous: the portal venous phase is a liver-timed acquisition that merely happens to fall in the same window, and borrowing its name for a neck or limb study imports a hepatic timing rationale that does not apply and hides the fact that the right delay is set by the target tissue. The errors are symmetrical — too early and arteries are far denser than nodes while an abscess rim has not yet enhanced; too late and everything equilibrates, collapsing the lesion-to-background difference the study depends on.

Safety checks this protocol carries

Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.

Prior contrast reaction and elective premedication· nurse pre scan
Intravenous access adequate for the planned injection· radiographer at scan
Metformin and iodinated contrast· radiographer at scan
Child-sized technique and contrast dose· radiographer at scan
Pregnancy status before an ionising exposure· radiographer at scan
Kidney function and intravenous iodinated contrast· radiographer at scan