What question does the consensus address?
Concern about kidney injury can delay an otherwise useful CT examination, complicate surveillance imaging or lead to an inadequate contrast dose. The 2026 Austrian consensus asks clinicians to weigh those diagnostic harms alongside the potential kidney risk.
Eight radiology and nephrology experts developed 11 consensus statements after reviewing research and international guidance. This is a consensus synthesis, not a new clinical trial. It aims to standardise practice in Austria; its recommendations should be recognised as such when applied elsewhere.
Does a creatinine rise establish contrast-induced injury?
Contrast-associated acute kidney injury (CA-AKI) describes timing, not proven causation. Patients needing imaging may already have infection, hypovolaemia, haemodynamic instability or exposure to nephrotoxic medicines. These can explain deterioration independently of contrast.
The term contrast-induced AKI implies a causal kidney injury. The authors argue that historical estimates of this risk were inflated by inadequate control groups and older contrast formulations. That argument does not mean that every post-contrast deterioration is benign: investigate alternative causes and assess the patient, rather than attributing the creatinine change automatically to contrast. [1]
Who needs kidney-function assessment before imaging?
The formal consensus identifies patients with an estimated glomerular filtration rate (eGFR) of ≤30 mL/min/1.73 m² as a risk population, particularly because evidence is insufficient. Existing AKI also needs separate consideration: a single creatinine-based eGFR is unreliable when kidney function is not in a steady state.
For elective outpatients, the working group proposes a practical screening question about CKD or kidney transplantation. If neither is present, it permits imaging without routine eGFR measurement. This is an outpatient screening approach, not a replacement for assessing an acutely unwell patient.
Where imaging is urgent, laboratory testing should not delay a necessary examination. In patients with AKI or advanced CKD, the decision rests on the clinical question, expected diagnostic benefit and availability of a genuinely adequate alternative.
Should everyone receive prophylactic hydration?
No. The statement favours clinical euvolaemia and individual assessment over blanket fluid administration. It describes no routine prophylactic hydration for patients with stable eGFR ≥30 mL/min/1.73 m², drawing particularly on elective-imaging studies.
For advanced CKD, the authors acknowledge that an improvement in renal outcomes from hydration has not been established adequately. They also emphasise the potential for cardiac decompensation, especially in patients with heart failure and other cardiovascular comorbidities.
If hydration is selected after assessing volume status and overload risk, the working group favours oral intake when feasible. This is a pragmatic consensus approach; it does not establish that oral hydration is superior to intravenous treatment in CKD stages 4–5. Fixed fluid volumes should not replace individual clinical assessment.
The source uses overlapping boundary definitions: its hydration discussion includes eGFR ≥30, while its formal at-risk statement uses ≤30. A value at the boundary warrants clinical interpretation rather than an automatic fluid prescription. [1]
What about contrast dose and preventive drugs?
For intravenous iodinated contrast, the consensus supports the usual amount needed to answer the diagnostic question. Arbitrary dose reduction may compromise image quality. Intra-arterial procedures have a different risk context, including procedural complexity, haemodynamic disturbance and contrast exposure.
| Clinical decision | Consensus position |
|---|---|
| Intravenous iodinated contrast | Use a diagnostic dose; avoid a reduction that makes the examination inadequate. |
| Intra-arterial iodinated contrast | Use low- or iso-osmolar agents at the lowest appropriate dose. |
| N-acetylcysteine | Not recommended as renal prophylaxis. |
| Sodium bicarbonate | Not recommended as routine renal prophylaxis; no demonstrated advantage over 0.9% saline. |
These distinctions matter: evidence and practice for a stable outpatient CT examination should not be transferred uncritically to a complex arterial intervention. [1]
Which medicines require review?
The consensus does not recommend routinely interrupting renin–angiotensin system blockers, sodium–glucose cotransporter 2 inhibitors or an established, stable diuretic regimen solely because contrast will be given.
Where feasible, it advises withholding potentially nephrotoxic non-steroidal anti-inflammatory drugs for 24–48 hours before and 48 hours after iodinated contrast. Low-dose aspirin used for its antiplatelet effect does not need to be stopped for contrast alone.
The paper also supports metformin continuation in its discussion of contrast administration, but does not provide a detailed exception-based protocol spanning AKI, acute illness and all routes of administration. It should not be read as blanket permission to continue treatment during clinical deterioration.
These are contrast-specific positions. Decisions arising from hypotension, volume depletion or another acute illness remain separate medication assessments; the statement is not a general sick-day medication protocol.
Who needs follow-up or a change in dialysis?
The working group supports checking kidney function after a few days in higher-risk patients according to clinical circumstances. It discusses the 48–72-hour interval used in other guidance, but its own formal recommendation is more individualised. Routine post-contrast testing is not proposed for everyone.
Patients already receiving dialysis can undergo indicated contrast imaging even when residual kidney function or urine output remains. The consensus does not recommend altering the dialysis schedule solely because iodinated contrast was administered.
It also advises against initiating prophylactic dialysis or haemofiltration simply to remove contrast or prevent CA-AKI. This does not displace kidney replacement therapy for standard clinical indications. [1]
How does the advice differ for gadolinium?
The MRI discussion focuses on the particular gadolinium-based contrast agent and its risk category. Older agents associated with nephrogenic systemic fibrosis should not be treated as interchangeable with contemporary low-risk agents.
The consensus permits Group II low-risk agents at licensed doses even in severe kidney impairment or dialysis, and states that routine eGFR measurement before these agents is not required.
| Reassuring statement | Essential qualification |
|---|---|
| Group II agents can be used with severe kidney impairment. | Identify the actual agent and use the licensed dose. |
| Routine eGFR testing is not required before Group II agents under this consensus. | This is not a statement about every gadolinium agent or high-dose intra-arterial administration. |
| Imaging can proceed in patients on dialysis. | Do not assume that contrast administration requires urgent or additional dialysis. |
Where should interpretation remain cautious?
Evidence remains limited in advanced CKD and AKI, and several practical recommendations reflect expert judgement. Hydration studies in elective, relatively stable populations cannot settle every decision in a haemodynamically unstable patient. Similarly, a temporal association with AKI cannot establish that contrast caused it—or that contrast played no part.
The authors disclose no conflicts of interest; open-access funding was provided by Karl Landsteiner University. This review draws its clinical content from the supplied consensus rather than adding a separate guideline comparison.
Clinical takeaway
Begin with the diagnostic question, identify AKI or advanced CKD, assess volume status and select the appropriate contrast agent and route. The Austrian consensus supports timely, clinically indicated imaging with proportionate precautions, while acknowledging that evidence is weakest in the patients who most need individual judgement.
Full reference
1. Heinz G, Windpessl M, Ökrösi A, Krestan C, Lampichler K, Bond G, Säemann M, Hohenstein-Scheibenecker K. Jodhaltige und gadoliniumhaltige Kontrastmittel und Nierenkrankheit: Konsensus-Statement der Österreichischen Gesellschaft für Radiologie (OERG) und der Österreichischen Gesellschaft für Nephrologie (ÖGN). Wiener klinische Wochenschrift. Published online 27 October 2026. doi:10.1007/s00508-026-02822-9.