First and second year — the floor first, then every step
Bilious vomiting in a neonate is a surgical emergency until proven otherwise. The upper GI contrast study decides: the duodenojejunal flexure must lie left of the left pedicle at the level of the duodenal bulb. Ultrasound adds the whirlpool sign and the SMA/SMV relationship.
Orient first
Normal rotation fixes the duodenojejunal flexure (DJF) left of the spine at the level of the bulb and the caecum in the right lower quadrant; a narrow mesenteric base is what twists.
Midgut volvulus can infarct the whole small bowel within hours.
The SMV normally lies to the right of the SMA; reversal suggests malrotation, but a normal relationship does not exclude it.
Acquire the study
Supine frontal and lateral views as the first contrast passes the duodenum; minimise screening time with pulsed fluoroscopy.
The manoeuvre
Frontal view: the DJF left of the left vertebral pedicle and at the level of the duodenal bulb.
Lateral view: the duodenum retroperitoneal (posterior) across its course.
Corkscrew configuration of the proximal jejunum (volvulus) or abrupt beak.
Small bowel position (right-sided jejunum).
What confirms it
Abnormal DJF position, corkscrew duodenum, or a whirlpool sign.
What licenses you to exclude it
A normally positioned DJF on a technically good upper GI study.
The classic misread
A DJF displaced by a distended stomach or a feeding tube — repeat after decompression.
Reference values
Each value carries the caveat that keeps it from being misused. Normal limits and diagnostic criteria are kept apart on purpose: a disease cut-off read as a normal range is the more dangerous mistake.
Diagnostic criteria
Midgut rotation · SMA–SMV relationship
the SMV lies to the RIGHT of the SMA; inversion (SMV to the left) is the malrotation flag and prompts a search for the D3 third-part duodenal course
A normal SMA–SMV relationship does not completely exclude malrotation. The whirl of midgut volvulus is the emergency pattern (next entry).
USG · CT · Fluoroscopy · paediatric
Midgut volvulus · Whirl-sign / corkscrew — how to report it
a named emergency pattern: swirling of SMV around SMA with a corkscrew duodenum on contrast — qualitative, not a turn-count that makes or excludes the diagnosis
This is a surgical emergency the images support. A normal study does not wait if the clinical picture is volvulus.
USG · CT · Fluoroscopy · paediatric
Midgut (malrotation checklist) · How to apply the already-registered SMA/SMV and whirl entries
DJ flexure to the left of the spine at the level of the pylorus on an upper GI, plus SMA/SMV relationship (already registered) — a checklist, not a fake angle
A normal SMA/SMV does not entirely exclude malrotation. The upper GI is the anatomic test.
Fluoroscopy · USG · paediatric
See it on real cases
Direct links to Radiopaedia — the reference article and worked cases with their images. Each opens on Radiopaedia.