Contrast swallow
Oropharynx to gastro-oesophageal junction
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
- Suspected aspiration or dysphagia, with speech and language therapy input.
- Suspected anastomotic leak or perforation after oesophageal surgery.
- Stricture, pouch or motility assessment.
Technique
- Water-soluble contrast is used first where perforation or leak is suspected; barium gives better mucosal detail once leak is excluded.
Where it goes wrong
- Barium in the mediastinum or peritoneum causes an intense inflammatory reaction, which is why the water-soluble-first rule exists when a leak is possible.
Clinical questions that reach this study
Contrast
Acquisition
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.
- Positive oral contrastIngested in divided volumes beginning roughly 60 min before scanning (commonly split doses at about 60, 45 and 15 min), so that the bolus front reaches the distal small bowel. Confirm locally.
A dense intraluminal agent labels bowel as bowel. The transferable principle is that the hardest structure to exclude on abdominal CT is unopacified bowel masquerading as something else — a collection, a mass, a leak, an abscess — and that the problem is worst exactly where mesenteric fat planes are thinnest, in the cachectic and the paediatric patient. Positive agents also demonstrate luminal continuity, so extraluminal contrast becomes direct evidence of perforation, leak or fistula. The trade-offs are symmetrical and important: the same density obscures mucosal enhancement, defeats bowel-wall assessment, degrades CT angiographic and three-dimensional reconstructions, and creates streak artefact, which is why several high-volume indications deliberately use a neutral agent instead.
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.
- Pregnancy status before an ionising exposure· radiographer at scan