, ACR Manual on Contrast
Media
2024
ACR Committee on Drugs and Contrast Media
© Copyright 2024 American College of Radiology
, TABLE OF CONTENTS
Topic Page
1. Preface 1
2. Version History 2
3. Introduction 4
4. Patient Selection and Preparation Strategies Before Contrast Medium Administration 5
5. Fasting Prior to Intravascular Contrast Media Administration 14
6. Safe Injection of Contrast Media 15
7. Extravasation of Contrast Media – 2022 Evidence Based Update 19
8. Allergic-Like And Physiologic Reactions to Intravascular Iodinated Contrast Media 29
9. Contrast Media Warming 36
10. Post-Contrast Acute Kidney Injury and Contrast-Induced Nephropathy in Adults 40
11. Metformin 51
12. Contrast Media in Children 54
• Ferumoxytol as MRI Contrast Medium (New 2024 addition) 64
13. Gastrointestinal (GI) Contrast Media in Adults: Indications and Guidelines – 2024 Update 69
14. ACR–ASNR Position Statement on the Use of Gadolinium Contrast Agents 79
15. Adverse Reactions to Gadolinium-Based Contrast Media 80
• Gadolinium Pregnancy Screening Statement (2023 addition) 83
16. Nephrogenic Systemic Fibrosis (NSF) 84
• ACR Manual Classification of Gadolinium-Based Agents Relative to Nephrogenic Systemic Fibrosis 89
17. Ultrasound Contrast Media 92
18. Treatment of Contrast Reactions 95
19. Administration of Contrast Media to Pregnant or Potentially Pregnant Patients 97
20. Administration of Contrast Media to Women Who are Breast-Feeding – 2024 Evidenced Based Update 101
Table 1 – Categories of Acute Reactions 104
Table 2 – Treatment Of Acute Reactions to Contrast Media In Children 106
Table 3 – Management Of Acute Reactions to Contrast Media In Adults 113
Table 4 – Equipment For Contrast Reaction Kits in Radiology 121
Appendix A – Contrast Media Specifications 123
, PREFACE
This edition of the ACR Manual on Contrast Media replaces all earlier editions. It is being published as a web-based document
only so it can be updated as frequently as needed.
This manual was developed by the ACR Committee on Drugs and Contrast Media of the ACR Commission on Quality and
Safety as a guide for radiologists to enhance the safe and effective use of contrast media. The Committee offers this documen t
to practicing radiologists as a consensus of scientific evidence and clinical experience concerning the use of contrast media.
Suggestions for patient screening, premedication, recognition of adverse reactions, and emergency treatment of such reactions
are emphasized. Its major purpose is to provide useful information regarding contrast media used in daily practice.
The editorial staff sincerely thanks all who have contributed their knowledge and valuable time to this publication.
Members of the ACR Committee on Drugs and Contrast Media are:
Carolyn Wang, MD, Chair Robert J. McDonald, MD
Daniella Asch, MD Jennifer McDonald, PhD
Mustafa Shadi Rifaat Bashir, MD Benjamin Mervak, MD
Michael James Callahan, MD Jeffrey Newhouse, MD, FACR
Jonathan Dillman, MD, MSc Jay Pahade, MD
James Ellis, MD, FACR Jennifer G. Schopp, MD
Monica Forbes-Amrhein, MD Prasad R. Shankar, MD
Leah Gilligan, MD Kerry L. Thomas, MD
Pranay Krishnan, MD
Finally, the committee wishes to recognize the efforts of supporting members of the ACR staff.
The manual is copyright protected and the property of the American College of Radiology. Any reproduction or attempt to
sell this manual is strictly prohibited absent the express permission of the American College of Radiology.
ACR MANUAL ON CONTRAST MEDIA – PREFACE 1
, VERSION HISTORY
2024
Version 2024 of the ACR Manual on Contrast Media was published in July 2024 as a web-based product. Content changes may
take place as a result of changes in technology, clinical treatment, or other evidence-based decisions from the contrast committee.
The following changes have been made:
Last Updated Chapter Change
2010 Introduction Updated
2013 Chapter 7 – Allergic-like and Physiologic Reactions to Intravascular Iodinated Contrast Updated
Media
2013 Chapter 8 – Contrast Media in Children Updated
2013 Chapter 12 – Gastrointestinal (GI) Contrast Media in Adults: indications and Updated
Guidelines
2013 Chapter 19 - Administration of Contrast Media to Women Who Are Breast-Feeding Updated
2014 Chapter 11- Contrast Media in Children Updated
2014 Appendix A Updated
2015 Preface Updated
2016 Chapter 13– ACR-ASNR Position Statement on the Use of Gadolinium Contrast A collaborative statement on
Agents gadolinium deposition was added to the
manual
2016 Table 1 – Indications for Use of Iodinated Contrast Media Deleted
2016 Table 2 – Organ and System-Specific Adverse Effects from the Administration of Deleted
Iodine-Based or Gadolinium-Based Contrast Agents
2016 Chapter 9 – Metformin Updated footnote based on new FDA advisory
2016 Chapter 14 – Injection of Contrast Media New section on intra-osseous injection
2016 Chapter 13 – ACR-ASNR Position Statement on the Use of Gadolinium Contrast New Chapter added
Agents
2017 Chapter 15 – Nephrogenic Systemic Fibrosis Updated
2017 Chapter 4 – Patient Selection and Preparation Strategies Updated
2017 Chapter 17 – Ultrasound Contrast Media New chapter added
2017 Chapter 19 – Administration of Contrast Media to Pregnant or Potentially Pregnant Updated
Patients
2018 Chapter 5 – Injection of Contrast Media Updated
2018 Chapter 6 – Extravasation of Contrast Media Updated
2020 Chapter 18 – Treatment of Contrast Reactions Updated
2020 Table 4 – Equipment for Contrast Reaction Kits in Radiology Updated
ACR MANUAL ON CONTRAST MEDIA – VERSION HISTORY 2
,2020 Appendix (Approved Contrast Media Agents) Updated
2021 Chapter 5 - Fasting Prior to Intravascular Contrast Media Administration New added chapter
2021 Chapter 10 - Post-Contrast Acute Kidney Injury and Contrast-Induced ACR-NKF Consensus language harmonization
Nephropathy in Adults update with chapter title change
2021 Chapter 16 - Nephrogenic Systemic Fibrosis (NSF) ACR-NKF Consensus language harmonization
update
2022 Chapter 7 – Extravasation of Contrast Media Evidence based update with recommendations
and strength of evidence
2022 Chapter 15 - Adverse Reactions To Gadolinium-Based Contrast Media New Gadolinium Pregnancy Screening
Statement
2023 Chapter 16 - Nephrogenic Systemic Fibrosis (NSF) Updated Calculating eGFR for Adults
2023 TABLE 1. ACR Manual Classification of Gadolinium-Based Agents Relative to Gadopiclenol Update
Nephrogenic Systemic Fibrosis
2023 Appendix A – Contrast Media Specifications Gadopiclenol Update
2024 TABLE 1. ACR Manual Classification of Gadolinium-Based Agents Relative to Eovist Update
Nephrogenic Systemic Fibrosis
2024 Chapter 12 – Contrast Media in Children Update and New Ferumoxytol addition
2024 Chapter 13 - Gastrointestinal (GI) Contrast Media in Adults: indications and Updated
Guidelines
2024 Chapter 20 - Administration of Contrast Media to Women Who are Breast-Feeding Evidence based update with recommendations
and strength of evidence
ACR MANUAL ON CONTRAST MEDIA – VERSION HISTORY 3
, INTRODUCTION
Various forms of contrast media have been used to improve medical imaging. Their value has long been recognized, as
attested to by their common daily use in imaging departments worldwide. Like all other pharmaceuticals, however, these
agents are not completely devoid of risk. The major purpose of this manual is to assist radiologists in recognizing and
managing the small but real risks inherent in the use of contrast media.
Adverse side effects from the administration of contrast media vary from minor physiological disturbances to rare severe
life-threatening situations. Preparation for prompt treatment of contrast media reactions must include preparation for the
entire spectrum of potential adverse events and include prearranged response planning with availability of appropriately
trained personnel, equipment, and medications. Therefore, such preparation is best accomplished prior to approving and
performing these examinations. Additionally, an ongoing quality assurance and quality improvement program for all
radiologists and technologists and the requisite equipment are recommended. Thorough familiarity with the presentation
and emergency treatment of contrast media reactions must be part of the environment in which all intravascular contrast
media are administered.
Millions of radiological examinations assisted by intravascular contrast media are conducted each year in North America.
Although adverse side effects are infrequent, a detailed knowledge of the variety of side effects, their likelihood in
relationship to pre-existing conditions, and their treatment is required to insure optimal patient care.
As would be appropriate with any diagnostic procedure, preliminary considerations for the referring physician and the
radiologist include:
1. Assessment of patient risk versus potential benefit of the contrast-assisted examination.
2. Imaging alternatives that would provide the same or better diagnostic information.
3. Assurance of a valid clinical indication for each contrast medium administration.
Because of the documented low incidence of adverse events, intravenous injection of contrast media may be exempted from
the need for informed consent, but this decision should be based on state law, institutional policy, and departmental policy.
Usage Note: In this manual, the term “low-osmolality” in reference to radiographic iodinated contrast media is intended to
encompass both low-osmolality and iso-osmolality media, the former having osmolality approximately twice that of human
serum, and the latter having osmolality approximately that of human serum at conventionally used iodine concentrations for
vascular injection. Also, unless otherwise obvious in context, this manual focuses on issues concerning radiographic
iodinated contrast media.
ACR MANUAL ON CONTRAST MEDIA – INTRODUCTION 4
, PATIENT SELECTION AND PREPARATION STRATEGIES BEFORE
CONTRAST MEDIUM ADMINISTRATION
General Considerations
The approach to patients about to undergo a contrast-enhanced examination has four general goals:
1) Ensure that the administration of contrast is appropriate for the patient and the indication
2) Balance the likelihood of an adverse event with the benefit of the examination
3) Promote efficient and accurate diagnosis and treatment
4) Be prepared to treat a reaction should one occur (see Tables 2, and 3)
Achieving these aims depends on obtaining an appropriate and adequate history for each patient, considering the risks and
benefit of using or avoiding contrast medium, preparing the patient appropriately for the examination, having equipment
available to treat reactions, and ensuring that personnel with sufficient expertise are available to treat severe reactions.
The history obtained should focus on identification of factors that may indicate either a contraindication to contrast media use
or an increased likelihood of an adverse event. Screening questions should include historical elements that will affect decis ion-
making in the patient selection and preparation period.
Risk Factors for Adverse Reactions to Intravenous
Contrast Media Primary Considerations
Allergic-like reactions to modern iodinated and gadolinium-based contrast medium are uncommon (iodinated: 0.6% aggregate
[1], 0.04% severe [2]; gadolinium-based: 0.01-0.22% aggregate [2], 0.008% severe) [3]. Risk factors exist that increase the risk
of a contrast reaction. These generally increase the likelihood of a reaction by less than one order of magnitude, effectivel y
increasing the risk that an uncommon event will occur, but not guaranteeing a reaction will take place. The following are some
examples:
Allergy: Patients who have had a prior allergic-like reaction or unknown-type reaction (i.e., a reaction of unknown
manifestation) to contrast medium have an approximately 5-fold increased risk of developing a future allergic -like reaction if
exposed to the same class of contrast medium again [2]. A prior allergic-like or unknown type reaction to the same class of
contrast medium is considered the greatest risk factor for predicting future adverse events.
In general, patients with unrelated allergies are at a 2- to 3-fold increased risk of an allergic-like contrast reaction, but due to
the modest increased risk, restricting contrast medium use or premedicating solely on the basis of unrelated allergies is n ot
recommended. Patients with shellfish or povidone-iodine (e.g., Betadine ® ) allergies are at no greater risk from iodinated contrast
medium than are patients with other allergies (i.e., neither is a significant risk factor) [4,5].
There is no cross-reactivity between different classes of contrast medium. For example, a prior reaction to gadolinium -based
contrast medium does not predict a future reaction to iodinated contrast medium, or vice versa, more than any other unrelated
allergy.
Asthma: A history of asthma increases the likelihood of an allergic-like contrast reaction [2,6].
Patients with asthma may be more prone to develop bronchospasm. Due to the modest increased risk, restricting contrast
medium use or premedicating solely on the basis of a history of asthma is not recommended.
Renal Insufficiency: Screening and selection strategies to mitigate the possible risks of the non-allergic adverse events of
contrast-induced nephrotoxicity (CIN) and nephrogenic systemic fibrosis (NSF) can be found in the Chapters on Post-Contrast
Acute Kidney Injury and Contrast Induced Nephropathy in Adults and Nephrogenic Systemic Fibrosis.
Cardiac Status: Patients with severe cardiac disease may be at increased risk of a non-allergic cardiac event if an allergic-like
or non-allergic contrast reaction occurs. These include symptomatic patients (e.g., patients with angina or congestive heart
PATIENT SELECTION AND PREPARATION STRATEGIES BEFORE CONTRAST MEDIUM ADMINISTRATION 5
, failure symptoms with minimal exertion) and also patients with severe aortic stenosis, cardiac arrhythmias, primary pulmonary
hypertension, or severe but compensated cardiomyopathy. Due to the modest increased risk, restricting contrast medium use
or premedicating solely on the basis of a patient’s cardiac status is not recommended.
Anxiety: There is some evidence that contrast reactions are more common in anxious patients [7]. Reassuring an anxious
patient before contrast medium injection may mitigate the likelihood of a mild contrast reaction.
Other Historical and Pre-Procedure Considerations
Age and Gender: Infants, neonates, children, and the elderly have lower reaction rates than middle -aged patients [1,8]. Male
patients have lower reaction rates than female patients. Due to the modest increased risk, restricting contrast medium use or
premedicating solely on the basis of patient age or gender is not recommended.
Beta-Blockers: Some have suggested that use of beta-blockers lowers the threshold for contrast reactions, increases the
severity of contrast reactions, and reduces the responsiveness of treatment with epinephrine [9]. Due to the modest increased
risk, restricting contrast medium use or premedicating solely on the basis of beta-blocker use is not recommended. Patients
on beta-blocker therapy do not need to discontinue their medication(s) prior to contrast medium administration.
Sickle-Cell Trait/Disease: Some have suggested that contrast medium exposure to patients with sickle cell trait or sickle
cell disease might increase the risk of an acute sickle crisis; however, there is no evidence this occurs with modern
iodinated or gadolinium-based contrast medium [10]. Therefore, restricting contrast medium use or premedicating solely
on the basis of sickle cell trait or sickle cell disease is not recommended.
Pheochromocytoma: There is no evidence that IV administration of modern iodinated or gadolinium -based contrast medium
increases the risk of hypertensive crisis in patients with pheochromocytoma [11]. Therefore, restricting contrast medium use
or premedicating solely on the basis of a history of pheochromocytoma is not recommended. Direct injection of any type of
contrast medium into the adrenal or renal arteries in a patient with pheochromocytoma has not been adequately studied and is
of unknown risk.
Myasthenia Gravis: There is a questionable relationship between IV iodinated contrast medium and exacerbations of
myasthenic symptoms in patients with myasthenia gravis. While one retrospective study showed no immediate increase in
myasthenic symptoms following the administration of iodinated or gadolinium-based contrast medium [12], another that
searched for myasthenic exacerbations occurring up to 45 days after a CT scan found that IV non -ionic iodinated contrast
medium was associated with an acute (within 1 day of contrast administration) myasthenic exacerbation in approximately 6 %
of patients (compared to a 1% acute exacerbation rate in patients who had undergone non-contrast CT, p=0.01) [13]. However,
that study was retrospective, and the number of events was small. Premedication is not recommended solely on the basis of a
history of myasthenia gravis. It is controversial whether iodinated contrast medium should be considered a relative
contraindication in patients with myasthenia gravis.
Hyperthyroidism: Patients with a history of hyperthyroidism can develop thyrotoxicosis after exposure to iodinated contrast
medium, but this complication is rare [14]. Therefore, restricting contrast medium use or premedicating solely on the basis of
a history of hyperthyroidism is not recommended. However, two special situations may affect this:
1. In patients with acute thyroid storm, iodinated contrast medium exposure can potentiate thyrotoxicosis; in such
patients, iodinated contrast medium should be avoided. Corticosteroid premedication in this setting is unlikely to
be helpful.
2. In patients considering radioactive iodine therapy or in patients undergoing radioactive iodine imaging of the
thyroid gland, administration of iodinated contrast medium can interfere with uptake of the treatment and diagnostic
dose. If iodinated contrast medium was administered, a washout period is suggested to minimize this interaction.
The washout period is ideally 3-4 weeks for patients with hyperthyroidism, and 6 weeks for patients with
hypothyroidism [15,16].
Normal Thyroid Function: Iodinated contrast medium does not affect thyroid function test results in patients with a
normally functioning thyroid gland [14]. Multiple studies have shown that a single dose of iodinated contrast medium
administered to a pregnant mother has no effect on neonatal thyroid function.
PATIENT SELECTION AND PREPARATION STRATEGIES BEFORE CONTRAST MEDIUM ADMINISTRATION 6
, Angiography: Iso-osmolality contrast media (IOCM) are associated with the least amount of vasospasm and the least
peripheral discomfort for peripheral angiograms [17]. Concomitant use of iodinated contrast medium with certain intra -
arterial medications (e.g., papaverine) may lead to precipitation of contrast medium and crystal or thrombus formation.
Decisions about the use and timing of such medication are outside the scope of this document.
Pretesting
Intradermal skin testing with contrast media to predict the likelihood of adverse reactions has not been shown to be useful
in minimizing reaction risk [18-20].
Corticosteroid Premedication
The purpose of corticosteroid premedication is to mitigate the likelihood of an allergic-like reaction in high- risk patients.
Etiology of Hypersensitivity Contrast Reactions: The etiological mechanism of most immediate hypersensitivity contrast
reactions is incompletely understood [21]. It is known, however, that approximately 90% of such adverse reactions are
associated with direct release of histamine and other mediators from circulating basophils and eosinophils. It is also genera lly
accepted that most adverse allergic-like reactions are not associated with the presence of increased IgE, and therefore are
unlikely to be typical IgE-mediated hypersensitivity reactions. However, some studies show evidence of IgE mediation [18].
No antibodies to IV contrast media have been consistently identified, and according to skin testing and basophil activation,
IgE-mediated allergy is uncommon, for example occurring in 4% of patients having anaphylaxis symptoms [19]. This likely
explains why patients who have never been exposed to contrast media can experience a severe hypersensitivity reaction on
first exposure. Prior sensitization is not required for a contrast reaction to occur.
Pathophysiologic explanations for allergic -like hypersensitivity reactions include activation of mast cells and basophils
releasing histamine, activation of the contact and complement systems, conversion of L-arginine into nitric oxide, activation
of the XII clotting system leading to production of bradykinin [10], and development of “pseudoantigens” [22].
The osmolality of the contrast medium as well as the size and complexity of the molecule has potential influence on the
likelihood of contrast reactions. Hyperosmolality is associated with stimulation of histamine release from basophils and mast
cells. Increase in the size and complexity of the contrast molecule may potentiate the release of histamine [23,24]. There is
some evidence to suggest that low-osmolality nonionic monomers produce lower levels of histamine release from basophils
compared with high-osmolality ionic monomers, low-osmolality ionic dimers and iso-osmolality nonionic dimers [24]. Low-
osmolality monomeric contrast media also are associated with a reduced likelihood of physiologic reactions following
intravenous administration (i.e., non-allergic-like; e.g., nausea and vomiting). In general, non -ionic iodinated contrast media
are associated with less adverse events than ionic contrast media (iodinated and gadolinium - based) [2,25].
Benefits of Premedication: A randomized trial showed that premedication of average-risk patients prior to high- osmolality
iodinated contrast medium administration reduces the likelihood of immediate adverse events of all severity [21]. However,
high-osmolality contrast medium is no longer used for intravascular purposes.
Another randomized trial showed that premedication of average-risk patients prior to modern low- osmolality iodinated contrast
medium administration reduce the likelihood of mild and aggregate immediate adverse events, but the trial was underpowered
to evaluate the effect on moderate and severe reactions [26].
Both of these randomized trials of premedication did not study the effect of premedication in high -risk patients who are
usually premedicated today, and neither study was sufficiently powered to evaluate the efficacy of premedication in the
prevention of moderate or severe reactions [21,26].
Nonetheless, many experts believe that premedication does reduce the likelihood of a reaction in high - risk patients receiving
low-osmolality iodinated contrast medium [26], although the number needed to treat to prevent a reaction is high [27,28].
One study estimated that the number needed to premedicate to prevent one reaction in high-risk patients was 69 for a reaction
of any severity and 569 for a severe reaction [27]. Another study estimated the number needed to treat to prevent a lethal
reaction in high-risk patients to be 50,000 [28].
PATIENT SELECTION AND PREPARATION STRATEGIES BEFORE CONTRAST MEDIUM ADMINISTRATION 7
