A practical, evidence-based guide for emergency physicians and emergency radiology teams.

Contrast-enhanced imaging is part of everyday emergency medicine. We use it because it often changes what we can diagnose: pulmonary embolism, aortic emergencies, active hemorrhage, mesenteric ischemia, vascular injury, complicated infection, abscess, major trauma, and many other time-sensitive conditions.

Yet contrast still creates unnecessary delays. A patient reports a “shellfish allergy.” Another has an eGFR of 38. Someone is taking metformin. A previous CT caused nausea. The patient ate two hours ago. Or a clinically important scan is delayed while everyone waits for a steroid regimen to finish.

The opposite problem also exists. Modern contrast media are generally well tolerated, but they are not risk-free. Severe hypersensitivity reactions are uncommon but real. Extravasation can occasionally cause significant tissue injury. Acute kidney injury and advanced chronic kidney disease require thoughtful assessment. And any department administering intravascular contrast must be prepared to manage anaphylaxis and cardiovascular deterioration.

The safest approach is therefore neither “avoid contrast whenever there is risk” nor “contrast is harmless.”

Use contrast when it materially improves diagnosis, identify the specific risk the patient actually has, reduce that risk when possible without creating a more dangerous diagnostic delay, and be prepared for the uncommon serious complication.

This review is based primarily on the 2026 ACR Manual on Contrast Media, supplemented where appropriate by the ACR–AAAAI hypersensitivity consensus, the ACR–NKF kidney consensus, current anaphylaxis guidance, and emerging emergency-department literature.

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1. Start with the diagnostic question

Before asking, “Can this patient receive contrast?” ask:

What are we trying to diagnose, and will contrast materially improve the examination?

That changes the entire discussion.

If the concern is aortic dissection, pulmonary embolism, mesenteric ischemia, active bleeding, vascular injury, abscess, or another serious diagnosis, the risk of an inadequate or delayed examination must be considered alongside the potential risk of contrast.

The ACR framework is straightforward: confirm that contrast is appropriate for the indication, consider the patient-specific risks, consider whether another study can provide equivalent information, and be prepared to manage an adverse reaction.

The ACR–NKF consensus makes the same point in patients with kidney disease: withholding a necessary contrast-enhanced CT can cause indirect harm through delayed diagnosis or misdiagnosis. (RSNA Publications Online)

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Previous Contrast Reactions

2. “Contrast allergy” is not enough history

When a patient says, “I am allergic to contrast,” ask what actually happened.

There is a major difference between:

• warmth or altered taste,
• nausea or vomiting,
• isolated urticaria,
• diffuse urticaria,
• facial edema,
• bronchospasm,
• throat tightness or hoarseness,
• hypotension,
• and previous anaphylaxis.

The ACR separates acute reactions into allergic-like and physiologic reactions because the distinction changes management.

Warmth, nausea, vomiting, and vasovagal reactions are generally physiologic. Urticaria, angioedema, bronchospasm, and laryngeal symptoms are allergic-like.

This matters because steroid premedication is intended to reduce recurrent allergic-like reactions. It does not prevent physiologic reactions.

For a previous reaction, try to establish four things:

Which agent was given? What happened? How quickly did it happen? How severe was it and what treatment was required?

If possible, record the specific agent, not simply “contrast allergy.” The 2025 ACR–AAAAI consensus specifically emphasizes documenting the symptoms, severity, and culprit agent because those details affect the strategy for future exposure. (RSNA Publications Online)

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3. Shellfish allergy is not iodinated-contrast allergy

This remains one of the most persistent misconceptions around contrast.

A shellfish allergy does not create a special risk from iodinated contrast. Neither does allergy to povidone-iodine or Betadine.

Patients with unrelated allergies or asthma may have a modestly increased risk of allergic-like reactions, but the ACR does not recommend routine contrast avoidance or premedication solely for these conditions.

There is also no specific immunologic cross-reactivity between iodinated contrast and gadolinium-based contrast. A previous reaction to one class should not simply be relabeled as an allergy to the other.

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4. Premedication is not guaranteed protection

This is an area where practice is evolving.

The 2026 ACR manual still states that when accelerated IV corticosteroid prophylaxis is used, the regimen with supporting evidence lasts approximately 4–5 hours. Regimens shorter than that have not historically been shown to be effective. Premedication also does not eliminate reactions: breakthrough reactions occur despite prophylaxis.

But newer guidance is more selective about who needs premedication in the first place.

The 2025 joint ACR–AAAAI consensus generally recommends:

Previous immediate iodinated-contrast reaction	Practical approach
Mild	Routine corticosteroid premedication generally not recommended; switch the culprit agent when known and feasible
Moderate	Switch agents when feasible; premedication may be considered
Severe	Consider an adequate alternative study first; if iodinated contrast remains necessary, consider agent substitution plus premedication when feasible, with appropriate resuscitation capability

The consensus also makes clear that the quality of evidence is limited, particularly because moderate and severe reactions are uncommon. (RSNA Publications Online)

Switching the contrast agent may matter more than another steroid dose

If a patient previously reacted to a known iodinated agent, ask radiology:

Can we use a different iodinated contrast agent?

The ACR manual notes that changing agents within the same class may reduce recurrence, and observational studies suggest that switching may have an effect at least comparable to, and possibly greater than, premedication alone. Combining strategies may reduce risk further in selected high-risk patients.

That makes accurate documentation of the culprit agent clinically useful.

What about the “four-hour rule”?

The guideline and the emerging evidence are not perfectly aligned.

The ACR manual continues to support approximately 4–5 hours when an accelerated IV corticosteroid regimen is being used. However, a 2026 multicenter retrospective study from five emergency departments compared 279 patients who received iodinated contrast within four hours of IV premedication with 68 who received contrast after more than four hours. Breakthrough reactions occurred in 3% versus 4%, respectively; there were no severe reactions. (Jove Visualize)

That study is important, but it does not prove equivalence. It was retrospective, the >4-hour group was relatively small, and only 11 reactions occurred.

A reasonable current interpretation is:

ACR still recommends the established 4–5-hour accelerated regimen when premedication is indicated and time permits. Emerging ED evidence questions whether that duration is always necessary, but it has not yet overturned the guideline. More importantly, a time-critical examination should not be dangerously delayed simply to complete prophylaxis of uncertain benefit.

The ACR manual itself allows urgent contrast administration without completed premedication when the diagnostic need outweighs the potential prophylactic benefit, provided an appropriate resuscitation-capable team is available.

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Renal Considerations

5. CA-AKI and CI-AKI are not the same thing

Much of the historical fear surrounding contrast and the kidneys came from treating every post-contrast creatinine rise as contrast nephrotoxicity.

These are different concepts:

Contrast-associated AKI (CA-AKI) means AKI that occurs after contrast administration. It describes timing.

Contrast-induced AKI (CI-AKI) means AKI caused by the contrast itself. It implies causation.

A patient with sepsis, hypotension, nephrotoxic medications, dehydration, major surgery, or critical illness may develop AKI after a contrast CT without the contrast necessarily being the cause.

The ACR considers true CI-AKI to be a real entity, but the attributable risk from modern IV iodinated contrast is substantially lower and more uncertain than older uncontrolled literature suggested. The ACR–NKF consensus similarly concludes that historical risk was overstated partly because CA-AKI and CI-AKI were conflated. (RSNA Publications Online)

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6. eGFR only makes sense when renal function is reasonably stable

For adults undergoing IV iodinated contrast CT, a practical interpretation is:

Renal status	Practical interpretation
Stable eGFR ≥45 mL/min/1.73 m²	Evidence is reassuring; routine renal prophylaxis is generally unnecessary
Stable eGFR 30–44	Evidence for an independent nephrotoxic effect is weak and attributable risk appears low; routine prophylaxis is generally unnecessary, although it may be considered in selected high-risk circumstances
Stable eGFR <30	Higher-risk group; weigh diagnostic benefit, alternatives, and whether prophylaxis is appropriate
Known or suspected AKI	A calculated eGFR is unreliable; assess creatinine trajectory, urine output, clinical context, and diagnostic urgency. Avoid contrast when an adequate alternative exists, but do not automatically withhold a necessary study

ACR states that there is very little evidence that IV iodinated contrast is an independent AKI risk when stable eGFR is ≥30 mL/min/1.73 m². The ACR–NKF consensus recommends prophylaxis for AKI or eGFR <30 in patients not receiving maintenance dialysis and allows consideration of prophylaxis in selected high-risk patients with eGFR 30–44. (RSNA Publications Online)

The important word is stable.

A patient with longstanding CKD and eGFR 38 is not the same physiological problem as a septic patient whose creatinine has risen rapidly and whose calculated eGFR happens to be 38.

During evolving AKI, creatinine is not at steady state, so the reported eGFR should not be interpreted as though it were a stable measurement of filtration.

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7. AKI or eGFR <30 does not automatically mean “no contrast”

These patients require more thought, not automatic cancellation.

Ask:

Is the diagnosis important? Is there an adequate alternative? Will delay matter? Can risk be reduced without compromising the study?

If the study is necessary for a life-threatening diagnosis, kidney dysfunction is generally a relative rather than absolute contraindication. The ACR–NKF consensus specifically states that necessary contrast should not be withheld solely because of kidney function in a life-threatening situation. (RSNA Publications Online)

What renal prophylaxis actually means

For patients in whom prophylaxis is appropriate, ACR favors IV isotonic volume expansion, typically 0.9% saline, provided the patient can tolerate it. The ideal volume and timing are not firmly established.

That last qualification matters.

A patient with decompensated heart failure or pulmonary edema can be harmed by indiscriminate fluid loading. “Renal protection” should not become an automatic liter-of-saline order without considering the circulation.

The ACR does not recommend routine:

• N-acetylcysteine,
• mannitol,
• furosemide,
• prophylactic hemodialysis,
• or arbitrary reduction of contrast below a diagnostic dose.

A poorly enhanced scan may expose the patient to contrast while still failing to answer the question.

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8. There is no universal evidence-based 24-hour prohibition on repeat contrast

Emergency patients sometimes need repeated imaging.

A trauma patient may deteriorate after the initial CT. A stroke patient may require additional vascular imaging. A postoperative patient may develop a new complication.

The ACR does not establish a mandatory 24-hour interval between IV iodinated contrast administrations. Evidence is insufficient to show that a universal 24-hour waiting period is protective.

High-risk patients—particularly those with AKI or severe CKD—deserve greater caution, but the decision remains clinical.

Also, checking serum creatinine only a few hours after the first examination generally does not tell you whether contrast-associated kidney injury will develop; creatinine changes too slowly.

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9. Dialysis patients are not all the same

The useful distinction is whether the patient has residual kidney function.

A completely anuric patient with end-stage kidney failure has no remaining filtration function to lose from iodinated contrast.

A dialysis patient who still produces a meaningful amount of urine may have residual renal function worth preserving. The ACR uses roughly more than 1–2 cups of urine per day (236–473 mL/day) as a pragmatic marker of a nonanuric dialysis patient who should be approached more like a high-risk patient with severe CKD or AKI.

Importantly, the ACR does not recommend initiating dialysis, adding an extra dialysis session, or changing the dialysis schedule solely because iodinated contrast was given.

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10. Metformin: the issue is renal deterioration, not a direct contrast–metformin interaction

Metformin does not increase the risk of CI-AKI.

The concern is that if significant renal dysfunction develops, metformin clearance decreases and accumulation may contribute to lactic acidosis.

Under ACR guidance:

No AKI and eGFR ≥30:
Metformin does not need to be routinely stopped solely because the patient is receiving routine IV iodinated contrast.

AKI, eGFR <30, or certain arterial catheter procedures with potential renal embolic risk:
Withhold metformin at or before the procedure, continue the hold for 48 hours, and reassess renal function before restarting.

The FDA labeling remains more restrictive than the ACR approach in some circumstances, so local pharmacy and institutional policy should be internally consistent.

Also remember that contrast is not the only reason to reconsider metformin. Severe sepsis, shock, significant hypoxia, or other conditions that increase lactate production or impair clearance may independently justify withholding it.

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Avoiding Unnecessary Imaging Delays

11. Routine fasting is not required for IV contrast

Routine fasting before modern IV iodinated contrast or gadolinium administration is not required by the ACR.

Available evidence has not demonstrated that fasting prevents contrast-related vomiting or aspiration, while fasting may create scheduling delays, discomfort, or hypoglycemia.

This does not override a separate fasting requirement for sedation, anesthesia, or another procedure.

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12. Positive oral contrast should not be automatic for every ED abdominal CT

This is another common source of unnecessary delay.

Evidence from emergency radiology studies supports omission of routine positive oral contrast for many adults undergoing CT for acute nontraumatic abdominal pain. In one ED protocol change, eliminating routine oral contrast reduced time from CT order to imaging and ED length of stay without demonstrating an increase in short-term missed diagnoses; subsequent studies and reviews have supported a more selective approach. (PubMed)

That does not mean oral contrast has no role.

Enteric contrast may be useful for selected questions such as:

• suspected gastrointestinal leak,
• fistula,
• selected postoperative complications,
• some bowel evaluations,
• or situations defined by the local radiology protocol.

When perforation is suspected, water-soluble enteric contrast is generally preferred to barium initially. But “water-soluble” does not mean harmless: hyperosmolar preparations can worsen fluid shifts and may cause serious pulmonary injury if aspirated.

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Vascular Access and Extravasation

13. A line that flushes is not automatically suitable for power injection

Contrast safety begins before the injector is activated.

The catheter, vein, injection rate, and pressure requirements should match the examination.

For higher-flow injections, a large forearm or antecubital vein is preferred when feasible. The catheter should be secured, patency assessed, and the patient should be able to report pain, tightness, burning, or swelling during injection when possible.

Central venous catheters, PICCs, and implanted ports should be power-injected only when the specific device and access port are certified for that use and within the manufacturer’s flow and pressure limits.

This deserves particular attention in difficult-access ED patients. Deep ultrasound-guided peripheral IVs may be necessary and often work well, but successful cannulation alone does not prove that the line is suitable for a high-pressure CTA injection.

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14. Contrast extravasation: examine the patient, not just the number of milliliters

Most contrast extravasations resolve without significant injury.

Severe complications such as compartment syndrome, blistering, tissue ulceration, or necrosis are rare—but they can develop, and the initial appearance may be deceptively mild.

When extravasation occurs:

• stop the injection,
• assess pain and tenderness,
• assess swelling and whether it is progressing,
• check sensation,
• check distal perfusion and capillary refill,
• assess active and passive movement,
• look for blistering or skin compromise,
• elevate the extremity,
• and apply an initial cold compress.

ACR does not recommend routine aspiration of the extravasated contrast, local corticosteroid injection, or hyaluronidase.

When should surgery be involved?

Not because an arbitrary threshold such as 100 mL was exceeded.

Urgent surgical assessment is appropriate when there is concern for serious tissue injury, including:

• severe or increasing pain,
• progressive swelling,
• impaired capillary refill or perfusion,
• altered sensation,
• worsening active or passive movement,
• blistering,
• ulceration,
• or suspected compartment syndrome.

The ACR specifically recommends basing escalation on the clinical findings rather than volume alone.

Remember that compartment syndrome has been reported even after relatively small-volume extravasation in confined areas such as the wrist.

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When the Patient Reacts

15. Do not begin with “contrast allergy.” Begin with the physiology.

If a patient deteriorates during or shortly after contrast administration, assess:

Airway. Breathing. Circulation. Mental status. Skin.

Ask what syndrome is developing.

Is there:

• isolated urticaria?
• angioedema?
• hoarseness or stridor?
• bronchospasm?
• hypoxemia?
• hypotension?
• bradycardia?
• pulmonary edema?
• seizure?
• cardiovascular collapse?

The ACR notes that nearly all life-threatening acute contrast reactions occur within the first approximately 20 minutes after injection.

Vasovagal physiology

A classic vasovagal reaction produces:

bradycardia + hypotension + pallor/diaphoresis ± nausea or syncope.

The physiology is increased vagal tone causing sinus/AV nodal slowing together with peripheral vasodilation.

Initial treatment includes appropriate supine positioning with leg elevation when feasible, monitoring, IV crystalloid when hypotension requires it, and atropine for persistent clinically important symptomatic bradycardia according to the current resuscitation protocol.

Heart rate is helpful, but it is not an absolute diagnostic rule.

Anaphylaxis

Think anaphylaxis when acute airway, breathing, or circulatory compromise occurs in a compatible setting, especially with bronchospasm, laryngeal symptoms, angioedema, urticaria, or shock.

A rash is not required.

Epinephrine is first-line treatment. Antihistamines are not a substitute for epinephrine. The ACR–AAAAI consensus gives both recommendations strong endorsement. (RSNA Publications Online)

For an adult with suspected anaphylaxis, contemporary general anaphylaxis guidance recommends IM epinephrine 0.5 mg (500 micrograms of 1 mg/mL) into the anterolateral thigh, with reassessment and repeat dosing at approximately five-minute intervals if life-threatening airway, breathing, or circulatory problems persist. (Resuscitation Council UK)

IV epinephrine carries considerably greater dosing and cardiovascular risk and should generally be reserved for experienced clinicians in an appropriately monitored setting, particularly in refractory shock. (Resuscitation Council UK)

One important guideline discrepancy

The ACR adult contrast-reaction table has historically favored IV epinephrine in some hypotensive contrast reactions because IM absorption may be impaired in profound shock. Contemporary general anaphylaxis guidance, however, favors IM-first treatment for most patients, reserving IV epinephrine for experienced clinicians and refractory cases.

For an ED-facing departmental protocol, this discrepancy should be resolved deliberately between emergency medicine, radiology, pharmacy, and the local resuscitation committee rather than leaving two conflicting medication algorithms in the CT area.

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Special Situations

16. Pregnancy: necessary iodinated contrast should not automatically be withheld

Pregnancy changes the risk–benefit discussion, but it does not automatically prohibit iodinated contrast.

When iodinated contrast is needed to answer an important diagnostic question, ACR does not recommend withholding it solely because the patient is pregnant.

The decision about ionizing radiation is separate and should be considered independently.

Iodinated contrast crosses the placenta, and pregnancy data are not unlimited. However, ACR does not recommend additional neonatal thyroid testing solely because the mother received routine intravascular water-soluble iodinated contrast during pregnancy beyond standard newborn screening.

Gadolinium is treated differently. Its use during pregnancy should be substantially more selective and generally reserved for situations in which the diagnostic information is important, cannot reasonably be obtained without gadolinium, and should not be deferred.

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17. Breastfeeding usually does not need to stop

Routine interruption of breastfeeding is not required after standard maternal iodinated or gadolinium-based contrast administration.

Only a very small fraction of the maternal dose reaches the infant systemically through breast milk, and ACR supports continued breastfeeding after these agents.

If a mother remains concerned after informed discussion, she may choose temporary interruption for roughly 12–24 hours and discard expressed milk during that period. ACR notes little value in interruption beyond 24 hours.

Routine infant thyroid testing is also not recommended solely because a breastfeeding mother received iodinated contrast.

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18. Direct iodinated contrast exposure in young children is a different issue

Do not confuse infant exposure through breast milk with direct intravascular contrast administration to the child.

The FDA updated its advice in 2023 and now recommends an individualized decision about thyroid monitoring in children three years of age or younger after intravascular iodinated contrast rather than universal testing.

Greater concern applies to higher-risk groups such as neonates, premature or very-low-birth-weight infants, and children with serious underlying conditions including some congenital heart disease. (American College of Radiology)

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19. Gadolinium in severe renal dysfunction: the agent matters

“Renal failure means no gadolinium” is too simplistic.

The risk of nephrogenic systemic fibrosis differs substantially among gadolinium-based contrast agents.

ACR classifies agents according to NSF risk:

• Group I agents account for most historically reported NSF and are avoided in high-risk patients.
• Group II agents have an extremely low observed NSF risk and are strongly preferred when gadolinium is necessary in a patient at risk.
• The current classification is agent-specific and can change as evidence accumulates.

The ED physician does not need to memorize every gadolinium brand name. What matters is communicating that the patient has AKI or severe CKD.

A useful conversation is simply:

“The patient has severe renal dysfunction. If gadolinium is necessary, can this be performed with an appropriate Group II agent?”

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20. A few uncommon but important exceptions

Acute thyroid storm

Iodinated contrast should be avoided when feasible because the iodine load can potentially worsen thyrotoxicosis. This is not an allergic mechanism, so corticosteroid “contrast allergy” premedication does not remove the concern.

Myasthenia gravis

The evidence linking modern iodinated contrast to acute myasthenic deterioration is limited and conflicting. ACR does not recommend routine allergy premedication solely because the patient has myasthenia gravis.

Pheochromocytoma

ACR states that there is no evidence that routine IV administration of modern iodinated or gadolinium contrast causes hypertensive crisis in patients with pheochromocytoma, and routine contrast avoidance or premedication solely for this diagnosis is not recommended. Direct arterial injection into adrenal or renal arteries is a different, less well-studied situation.

Historical concern about contrast-triggered catecholamine release was influenced by experience with older angiographic contrast practice; those concerns should not simply be extrapolated to modern routine IV nonionic contrast.

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The Five Questions That Cover Most ED Contrast Decisions

Rather than memorizing dozens of isolated rules, most emergency contrast decisions can be organized around five questions.

1. Will contrast materially improve the diagnosis?

If yes, include the harm of delayed or inadequate diagnosis in the risk–benefit decision.

2. Has the patient had a genuine previous reaction to this same contrast class?

Find out what actually happened and how severe it was. Identify the culprit agent whenever possible. For a previous mild immediate iodinated-contrast reaction, current ACR–AAAAI guidance generally favors agent substitution rather than routine steroid premedication. (RSNA Publications Online)

3. Is renal function stable?

Stable CKD with eGFR 38 and evolving AKI with an eGFR of 38 are not the same problem. Use the trend and clinical physiology, not the laboratory number alone.

4. Is there a circumstance that changes the plan?

Think about severe previous hypersensitivity, AKI or eGFR <30, residual renal function in dialysis, metformin, pregnancy, thyroid storm, severe renal dysfunction before gadolinium, difficult vascular access, or aspiration risk if enteric contrast is being considered.

5. If something goes wrong, are we ready?

The CT environment must be able to recognize and manage anaphylaxis, vasovagal hypotension, extravasation, airway compromise, and cardiovascular deterioration immediately.

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What Should Actually Change in the ED?

The evidence translates into practical changes in workflow:

• Stop using shellfish allergy or “iodine allergy” as automatic reasons to delay contrast.
• Document the actual reaction phenotype and the culprit contrast agent whenever possible.
• After a previous mild immediate iodinated-contrast reaction, think agent substitution before automatic steroid premedication.
• Do not treat eGFR 30 as a simplistic yes/no threshold.
• Distinguish stable CKD from evolving AKI.
• Do not automatically cancel necessary contrast imaging because a patient has AKI or eGFR <30; make an explicit risk–benefit decision.
• Do not routinely stop metformin for standard IV iodinated contrast when there is no AKI and eGFR is ≥30 under ACR guidance.
• Do not delay routine IV contrast merely because the patient recently ate.
• Do not impose a universal 24-hour prohibition on repeat contrast.
• Do not make positive oral contrast a routine prerequisite for every ED abdominal CT.
• Treat extravasation according to the clinical examination and trajectory, not a fixed volume threshold.
• Ensure that staff around contrast can distinguish vasovagal physiology from suspected anaphylaxis and can immediately activate the appropriate resuscitation response.

These changes do not make contrast risk-free. They make its use more rational, consistent, and safer.

Take-Home Message

The important question in emergency medicine is rarely whether contrast is simply “safe” or “unsafe.”

It is whether the diagnostic benefit justifies the specific risk in this patient.

A previous episode of warmth is not previous anaphylaxis. Shellfish allergy is not iodinated-contrast hypersensitivity. Stable eGFR 35 is not evolving AKI. Premedication does not guarantee protection. AKI does not automatically prohibit a lifesaving contrast study. A dialysis patient with residual urine output is different from an anuric patient. And a patient who becomes hypotensive after contrast needs a physiological assessment—not simply the label “contrast reaction.”

The practical approach is:

Use contrast when it meaningfully improves diagnosis. Identify the specific risk rather than relying on labels. Modify the agent, preparation, or monitoring when that meaningfully reduces risk. Do not allow low-value precautions to delay time-critical imaging. And make sure the CT environment is prepared to recognize and treat the rare serious complication promptly.

That is the balance between diagnostic benefit and contrast safety that emergency medicine and emergency radiology should be aiming for.

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References

1. American College of Radiology Committee on Drugs and Contrast Media. ACR Manual on Contrast Media. 2026 edition. Relevant chapters include patient selection and preparation, fasting, safe injection, extravasation, allergic-like and physiologic reactions, CA-AKI/CI-AKI, metformin, gastrointestinal contrast, NSF, pregnancy, breastfeeding, and treatment of acute reactions.
2. Wang C, Ramsey A, Lang D, et al. Management and Prevention of Hypersensitivity Reactions to Radiocontrast Media: A Consensus Statement from the American College of Radiology and the American Academy of Allergy, Asthma & Immunology. Radiology. 2025;315(2):e240100. doi:10.1148/radiol.240100. (RSNA Publications Online)
3. Davenport MS, Perazella MA, Yee J, et al. Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation. Radiology. 2020;294(3):660-668. doi:10.1148/radiol.2019192094. (RSNA Publications Online)
4. Shah CN, DiGaetano M, Aboloff J, et al. Challenging the 4-h premedication regimen for iodinated contrast allergy: A multicenter retrospective study. American Journal of Emergency Medicine. 2026. doi:10.1016/j.ajem.2026.08.041. (Jove Visualize)
5. Resuscitation Council UK. Emergency Treatment of Anaphylaxis: Guidelines for Healthcare Providers. Current detailed guidance on IM adrenaline and escalation of refractory anaphylaxis. (Resuscitation Council UK)
6. Levenson RB, Camacho MA, Horn E, et al. Eliminating routine oral contrast use for CT in the emergency department: impact on patient throughput and diagnosis. Emergency Radiology. 2012;19(6):513-517. doi:10.1007/s10140-012-1059-7. (PubMed)
7. Kielar AZ, Patlas MN, Katz DS. Oral contrast for CT in patients with acute non-traumatic abdominal and pelvic pain: what should be its current role? Emergency Radiology. 2016;23(5):477-481. doi:10.1007/s10140-016-1403-4. (PubMed)