Suspected malrotation with midgut volvulus

ACR AC Vomiting in Infants; ACR AC Acute Nonlocalized Abdominal Pain; Image Gently current guidance

Bilious vomiting in a neonate is midgut volvulus until proven otherwise, and it is a surgical emergency: the whole small bowel hangs on a narrow mesenteric pedicle and infarcts within hours of twisting. The correct vetting output is usually "yes, now, and phone the paediatric surgeons" rather than a protocol tweak — imaging is arranged alongside the surgical review, never in front of it. The upper GI contrast study is the reference standard for the position of the duodenojejunal flexure; ultrasound is a legitimate and increasingly used first study where the expertise exists; a normal abdominal radiograph excludes nothing.

A neonate or young infant with bilious (green) vomiting, with or without abdominal distension, tenderness, blood per rectum or shock — or an older child or adult with an acute abdomen on a background of intermittent bilious vomiting, recurrent central pain or failure to thrive.

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.

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

Upper GI contrast study

What we'd amend, and why

The upper GI contrast study is the reference standard because it answers the only anatomical question that matters: where the duodenojejunal flexure lies. On a true frontal view it should sit to the left of the left-sided vertebral pedicle at the level of the duodenal bulb, with the duodenum crossing the midline in the retroperitoneum. A flexure that is low, midline or right-sided, a corkscrew or spiral proximal jejunum, or a beaked duodenal obstruction, is the diagnosis. It takes minutes, needs only a small volume of contrast down a nasogastric tube in an infant who is already nil by mouth, and does not depend on the operator finding one specific vessel sign. What it must not do is delay the surgeon: in a peritonitic or shocked infant the study is arranged in parallel with the surgical review, or abandoned in favour of theatre.

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

How was this decided?

pathwayneonate-infant — Neonates and infants (and any request with no age stated)
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

Decision support only. Local protocol takes precedence.

Handled at the scanner(2)nothing for you to do

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

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.
For this indication dose control means pulsed low-frame-rate fluoroscopy, last-image-hold rather than extra exposures, tight collimation, and stopping the study once the duodenojejunal flexure has been documented. It never means delaying or declining the study: the radiation question here is trivially small against the loss of the midgut.
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.

Worth asking the referrer (3)

None of these hold the request up. They sharpen the protocol or the plan that follows.

How old is the child, in days or weeks?
It selects a different first study rather than modifying a protocol: fluoroscopy or ultrasound in an infant, CT in an older child or adult. A request that gives no age is deliberately answered as an infant, because on this card the cost of guessing wrong that way is an upper GI study in a teenager, while the cost of guessing the other way is a CT in a newborn. Stating the age is what turns a safe default into the right answer.
Was the vomit bilious, and is the abdomen distended, tender or the child haemodynamically unstable?
It sets the urgency and can override imaging altogether — an unstable infant with peritonism needs a laparotomy, not a fluoroscopy slot.
Has the child had a Ladd procedure or any previous abdominal surgery?
The duodenojejunal flexure stays abnormal after a Ladd procedure, so flexure position alone cannot be read as recurrent malrotation; the question after a Ladd is the mesenteric swirl, not the anatomy.

Pathways

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

Shocked or peritonitic infant — theatre, with imaging alongside

Role	Study & protocol	Why this answers the question
First line	Paediatric abdominal ultrasound Paediatric abdominal ultrasound usually appropriate	The decision in this infant is not which study — it is that the surgical team is called now, and that no imaging delays a laparotomy. A baby who is shocked, peritonitic or passing blood per rectum goes to theatre, and saying exactly that is the radiological contribution at this moment. What ultrasound adds is that it does not cost the child a journey: it is immediate, radiation-free and done at the cot side without leaving the resuscitation area, and it looks for the whirlpool — the clockwise wrap of superior mesenteric vein and mesentery around the artery — which is a direct sign of the twist rather than an inference from anatomy. A whirlpool in an unwell infant means theatre, not fluoroscopy. Its limits matter more in this child than in any other: roughly one in five affected children have a normal vein-to-artery relationship, so a normal or equivocal study in a shocked, peritonitic baby excludes nothing and must never be used to stand the surgeons down or to downgrade the urgency.
Second line	Upper GI contrast study Upper GI contrast study	The upper GI contrast study is still the reference standard for the position of the duodenojejunal flexure, and this infant still has it — once they are stable enough to leave the resuscitation area, or in parallel with the surgical review where the surgeons want the anatomy before they open. It is sequenced behind theatre rather than cancelled by instability. What it must not be is the reason a shocked baby waits: a fluoroscopy slot means a transfer out of resuscitation, a period of positioning and screening, and minutes the midgut does not have. Where it goes ahead, use a low-osmolar non-ionic water-soluble agent — aspiration of a high-osmolar ionic agent causes a chemical pneumonitis and its osmotic load causes fluid shifts in a baby with no reserve, and both matter more in a child who is already unstable.
Reasonable alternative	Abdominal radiograph Abdominal radiograph — supine	Usually the film that has already been taken, and worth looking at while the surgical conversation happens: a distended stomach and proximal duodenum with a paucity of distal gas, a double bubble with distal gas, or a gasless abdomen all support obstruction and shorten that conversation. It is not a rule-out, and in this child that point is sharper than usual — the film is normal or non-specifically gassy in a large share of proven midgut volvulus, so it can neither close the question nor lower the urgency in a baby who is already unstable.

This arm changes the order of the phone calls, not the availability of the studies. Ring the paediatric surgical team first; arrange imaging alongside the surgical review, never in front of it.
An infant compensates for hypovolaemia and then decompensates abruptly, so the trend and the perfusion matter more than a single blood pressure. If the centre has no paediatric surgery on site, the transfer call is the decision and it is made now.
Fluoroscopy dose is controlled by pulsed low frame rates, last-image-hold, tight collimation and stopping once the flexure is documented — never by hesitating over whether a sick baby should have the study at all.

Neonates and infants (and any request with no age stated)

Matches your inputs

Role	Study & protocol	Why this answers the question
First line	Upper GI contrast study Upper GI contrast study usually appropriate	The upper GI contrast study is the reference standard because it answers the only anatomical question that matters: where the duodenojejunal flexure lies. On a true frontal view it should sit to the left of the left-sided vertebral pedicle at the level of the duodenal bulb, with the duodenum crossing the midline in the retroperitoneum. A flexure that is low, midline or right-sided, a corkscrew or spiral proximal jejunum, or a beaked duodenal obstruction, is the diagnosis. It takes minutes, needs only a small volume of contrast down a nasogastric tube in an infant who is already nil by mouth, and does not depend on the operator finding one specific vessel sign. What it must not do is delay the surgeon: in a peritonitic or shocked infant the study is arranged in parallel with the surgical review, or abandoned in favour of theatre.
Reasonable alternative	Paediatric abdominal ultrasound Paediatric abdominal ultrasound	Ultrasound is a legitimate first study where the paediatric expertise exists, and several centres have moved to it as their initial test. It looks for two things: the relationship of the superior mesenteric vein to the artery — the vein normally lies to the right — and the whirlpool sign, the clockwise wrap of vein and mesentery around the artery, which is a direct sign of the twist rather than an inference from anatomy. Loss of the normal retroperitoneal position of the third part of the duodenum between aorta and SMA is a further useful sign. Published paediatric series report high sensitivity and specificity in experienced hands, and it is immediate, radiation-free and possible at the cot side in a sick infant. The honest limits are that a normal vessel relationship does not exclude malrotation — about one in five affected children have normally orientated vessels — that inverted vessels occur without malrotation, and that performance falls away outside units that do it often. So: a whirlpool in an unwell infant means theatre, not fluoroscopy; a normal or equivocal ultrasound with persistent clinical suspicion means the upper GI study still has to happen.
Reasonable alternative	Abdominal radiograph Abdominal radiograph — supine	The abdominal radiograph is usually the film that has already been taken, and it is worth looking at: a distended stomach and proximal duodenum with a paucity of distal gas, a double bubble WITH distal gas, or a gasless abdomen all support obstruction and shorten the conversation with the surgeons. It is emphatically not a rule-out. A normal or non-specifically gassy film is common in proven midgut volvulus, so a radiograph reported as normal must never be used to close the question or to downgrade urgency — the pathway continues to the upper GI study or ultrasound regardless of what the film shows.

The most time-critical decision on this card is made by telephone, not by the scanner. Vet it, accept it, and ring the paediatric surgical team while it is being booked.
No imaging should delay laparotomy in an unstable, peritonitic or shocked infant. The correct radiological answer at that point is to say exactly that.
Use a low-osmolar non-ionic water-soluble agent, or barium where there is no concern about perforation or aspiration. High-osmolar ionic agents have no place in a neonatal upper GI study: aspiration causes a chemical pneumonitis and the osmotic load causes fluid shifts in a baby with no reserve.
Fluoroscopy dose in an infant is controlled by pulsed low frame rates, last-image-hold, tight collimation and stopping once the flexure has been documented — not by hesitating over whether to do the study.

Older children and adults

Default

Role	Study & protocol	Why this answers the question
First line	CT Abdomen and Pelvis CT Abdomen and Pelvis — Portal Venous Phase usually appropriate	Beyond infancy this presents as an acute abdomen rather than as a bilious vomit, the differential is wide, and contrast-enhanced CT is the practical answer: it both makes the volvulus diagnosis and covers everything else the pain might be. The findings are direct — the whirl of mesentery and superior mesenteric vein around the artery, an inverted vessel relationship, a third part of the duodenum that never crosses the midline behind the SMA, an abnormally sited caecum — and, decisively for the surgeon, it shows the state of the bowel: closed-loop configuration, mesenteric congestion, reduced or absent mural enhancement, pneumatosis or portal venous gas. A single portal-venous phase answers the volvulus question, and the finding that changes the operation is loss of mural enhancement, so review on adjusted windows rather than one soft-tissue setting. Two protocol qualifiers. Where acute mesenteric ischaemia rather than the twist is the leading concern, add an arterial phase or request a CT mesenteric angiogram — an occluded or attenuated superior mesenteric artery is an arterial-phase finding and the portal-venous study shows only its consequences. And no positive oral contrast: it takes an hour and a half nobody has, dense luminal contrast masks the mural hypo-enhancement that is the whole point of the study, and it is unsafe in a patient going to theatre.
Second line	Upper GI contrast study Upper GI contrast study	For the stable older child or adult with intermittent bilious vomiting, recurrent central pain or failure to thrive — and for the patient whose CT was equivocal or was performed between episodes — the upper GI study still defines the position of the duodenojejunal flexure and remains the anatomical reference standard. In this group it is an elective problem-solving study: someone with an acute abdomen and a suspected volvulus should not be sent to fluoroscopy first.

This arm is reached only when an age of two or over has actually been stated. A request with no age recorded is answered as an infant, because that is the safe direction to be wrong in on this card — which is precisely why the age question is worth asking before anything is booked.
Malrotation found incidentally in an asymptomatic adult is a surgical discussion, not an emergency — the emergency is the twist, not the anatomy.
Where acute mesenteric ischaemia rather than the twist itself is the leading question, the acquisition changes: add an arterial phase, or request CT mesenteric angiography, because the portal-venous study shows the consequences of an occluded vessel better than it shows the vessel.

Pitfalls

Bilious vomiting in a neonate is a surgical emergency until proven otherwise, and imaging must not delay surgical review. The commonest serious error on this pathway is not the wrong protocol but the right protocol arranged too slowly — the surgical team is called when the request is vetted, not when the study is reported.
A normal abdominal radiograph does not exclude malrotation with volvulus. The film is normal or non-specifically gassy in a large share of proven cases, and accepting one as the answer to a bilious vomit is the classic false reassurance here.
A normal superior mesenteric vein-to-artery relationship on ultrasound does not exclude malrotation — roughly one in five affected children have normally orientated vessels — and inverted vessels occur without malrotation. The whirlpool is the specific sign, and its absence is not a negative study.
The duodenojejunal flexure is only interpretable on a genuinely frontal projection with the stomach not overdistended. A rotated infant, an overfilled stomach or a nasogastric tube displaces it; where the study is technically imperfect, report it as limited rather than reporting a position.
After a Ladd procedure the flexure stays abnormal and the caecum lies on the left, so a post-operative upper GI study cannot be read by flexure position alone. Recurrent volvulus after a Ladd is uncommon but well described.
Malrotation demonstrated anatomically is not proof that this episode is a volvulus, and a twist that has spontaneously detorsed leaves a near-normal study between attacks — which is exactly why older children and adults are diagnosed late.
Double bubble with distal gas suggests malrotation with volvulus or a duodenal web; double bubble with a gasless distal abdomen suggests duodenal atresia. The distal gas is the discriminator and it changes the urgency.
Reaching for CT in a neonate. It delivers a substantial dose to the most radiosensitive patient in the hospital, usually adds delay, and answers a question that fluoroscopy or ultrasound answer faster; it belongs to the older child and adult, or to the infant in whom a complication such as perforation is the actual question.
High-osmolar ionic water-soluble contrast in a neonatal upper GI study — aspiration causes a chemical pneumonitis and the osmotic load causes fluid shifts. Use a low-osmolar non-ionic agent, or barium where perforation and aspiration are not concerns.

Priors — what to pull first

Find any previous upper GI study or ultrasound: a technically adequate study documenting a normal duodenojejunal position is one of the few things that genuinely lowers the pre-test probability.
An operation note recording a Ladd procedure changes the interpretation of every subsequent study — the flexure is expected to remain abnormal afterwards.
Known heterotaxy, congenital diaphragmatic hernia, abdominal wall defect or complex congenital heart disease raises the prior probability of malrotation substantially.

What makes a good request

The surgical conversation happens at the moment the request is vetted, not when the study is reported. An infant who is peritonitic, shocked or has blood per rectum goes to theatre; saying so is the radiological contribution at that point.
A good request states the age in days or weeks, whether the vomit was bilious, whether the abdomen is distended or tender, and whether the child is stable enough to leave the resuscitation area.
Non-bilious vomiting does not exclude the diagnosis — a substantial minority of infants with proven volvulus vomit non-bilious — so the whole picture, not the colour alone, drives the pathway.
If the centre has neither paediatric fluoroscopy nor paediatric surgery on site, the decision is transfer and the transfer call is made now; the diagnostic study can be done at the receiving unit.

How these studies are acquired

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

Paediatric abdominal ultrasound Upper GI contrast study Abdominal radiograph — supine CT Abdomen and Pelvis — Portal Venous Phase

Confirm locally

Upper GI contrast study: 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

ACR Appropriateness Criteria — Vomiting in Infants · ACR Appropriateness Criteria
ACR Appropriateness Criteria — Acute Nonlocalized Abdominal Pain · ACR Appropriateness Criteria
Applegate KE, Anderson JM, Klatte EC. Intestinal malrotation in children: a problem-solving approach to the upper gastrointestinal series (RadioGraphics 2006) · Primary literature
Sizemore AW et al. Diagnostic performance of the upper gastrointestinal series in the evaluation of children with clinically suspected malrotation (Pediatric Radiology 2008) · Primary literature
Zhou LY et al. Usefulness of sonography in evaluating children suspected of malrotation, compared with an upper gastrointestinal contrast study (J Ultrasound Med 2015) · Primary literature
Image Gently Alliance — imaging children safely, including Step Lightly fluoroscopy guidance · Image Gently
European Society of Paediatric Radiology — paediatric imaging standards and task force outputs · Other
RCR standards for the communication of radiological reports and fail-safe alert notification — the mechanism for a finding that needs a surgeon now · RCR
Radiopaedia — intestinal malrotation and midgut volvulus · Radiopaedia
Strauss KJ et al. Image Gently: Ten Steps You Can Take to Optimize Image Quality and Lower CT Dose for Pediatric Patients (AJR) · Image Gently
AAPM Pediatric Routine Abdomen and Pelvis CT Protocol — size-based technique parameters · Other
The Ionising Radiation (Medical Exposure) Regulations 2017 (SI 2017/1322) — Schedule 2 requires written procedures for making enquiries of individuals of childbearing potential to establish whether they are or may be pregnant or breastfeeding; the operator is responsible for the practical aspects they carry out. · RCR
Society of Radiographers — The impact of IR(ME)R 2017 / IR(ME)R (NI) 2018 on pregnancy checking procedures · RCR
ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Patients with Ionizing Radiation — Fetal dose <50 mGy not shown to increase risk of pregnancy loss or malformation; attributable cancer risk approximately 0.4% per 10 mGy · Other
IAEA Radiation Protection of Patients — pregnancy enquiry is not needed for examinations in which the uterus is remote from a properly collimated primary beam (head, extremities) · Other

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