Incidence of contrast-induced nephropathy in patients with multiple myeloma undergoing contrast-enhanced CT

The Potential Biotherapeutic Targets of Contrast-Induced Acute Kidney Injury

Contrast-induced acute kidney injury (CI-AKI) is manifested by an abrupt decline in kidney function as a consequence of intravascular exposure to contrast media. With the increased applicability of medical imaging and interventional procedures that utilize contrast media for clinical diagnosis, CI-AKI is becoming the leading cause of renal dysfunction. The pathophysiological mechanism associated with CI-AKI involves renal medullary hypoxia, the direct toxicity of contrast agents, oxidative stress, apoptosis, inflammation, and epigenetic regulation. To date, there is no effective therapy for CI-AKI, except for the development of strategies that could reduce the toxicity profiles of contrast media. While most of these strategies have failed, evidence has shown that the proper use of personalized hydration, contrast medium, and high-dose statins may reduce the occurrence of CI-AKI. However, adequate risk predication and attempts to develop preventive strategies can be considered as the key determinants that can help eliminate CI-AKI. Additionally, a deeper understanding of the pathophysiological mechanism of CI-AKI is crucial to uncover molecular targets for the prevention of CI-AKI. This review has taken a step further to solidify the current known molecular mechanisms of CI-AKI and elaborate the biomarkers that are used to detect early-stage CI-AKI. On this foundation, this review will analyze the molecular targets relating to apoptosis, inflammation, oxidative stress, and epigenetics, and, thus, provide a strong rationale for therapeutic intervention in the prevention of CI-AKI.

THE RISK OF ACUTE KIDNEY INJURY AFTER ELECTIVE VERSUS EMERGENCY CORONARY INTERVENTION

OBJECTIVE

The aim: A serious and common complication after percutaneous coronary intervention is acute kidney injury, which is associated with an increased risk of renal, cardiovascular and even mortality; therefore, early prognosis and identification of patients at higher risk are essential for early initiation of preventive measures. The aim of this study is to predict and compare the risk for the development of CI-AKI in patient with ACS who undergo emergency PCI or elective (i.e. after medical stabilization) PCI by utilizing the sensitivity of serum NGAL as an early and reliable predictor for CI-AK.

PATIENTS AND METHODS

Materials and methods: The study include 37 patients with acute coronary syndrome, baseline serum creatinine, complete blood count and pre and two hours post operative serum neutrophil gelatinase-associated lipocalin were measured and all patients underwent percutaneous coronary intervention according to the standard protocol used in Al Najaf Cardiac Center.

RESULTS

Results: This is a Two-Arm study that included a total of 37 patients with acute coronary syndrome aged 38-83 years. Eighteen of them had emergency percutaneous coronary intervention while the remaining 19 had elective percutaneous coronary intervention (after medical stabilization). Elevation of serum neutrophil gelatinase-associated lipocalin level two hours after percutaneous coronary intervention was found to be significantly higher among emergency percutaneous coronary intervention group compared to elective group.

CONCLUSION

Conclusions: Acute coronary syndrome patients are undergoing emergency percutaneous coronary intervention are at an increasing risk for the development of contrast induced acute kidney injury than those undergoing elective percutaneous coronary intervention.

Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m² who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m² at the discretion of the ordering clinician. This article is a simultaneous joint publication in Radiology and Kidney Medicine. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article.

Use of Intravenous Iodinated Contrast Media in Patients With Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m² who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m² at the discretion of the ordering clinician.

Contrast Induced Acute Kidney Injury and Direct Cytotoxicity of Iodinated Radiocontrast Media on Renal Proximal Tubule Cells

The administration of intravenous iodinated radiocontrast media (RCM) to visualize internal structures during diagnostic procedures has increased exponentially since their first use in 1928. A serious side effect of RCM exposure is contrast-induced acute kidney injury (CI-AKI), which is defined as an abrupt and prolonged decline in renal function occurring 48-72 hours after injection. Multiple attempts have been made to decrease the toxicity of RCM by altering ionic strength and osmolarity, yet there is little evidence to substantiate that a specific RCM is superior in avoiding CI-AKI. RCM-associated kidney dysfunction is largely attributed to alterations in renal hemodynamics, specifically renal vasoconstriction; however, numerous studies indicate direct cytotoxicity as a source of epithelial damage. Exposure of in vitro renal proximal tubule cells to RCM has been shown to affect proximal tubule epithelium in the following manner: 1) changes to cellular morphology in the form of vacuolization; 2) increased production of reactive oxygen species, resulting in oxidative stress; 3) mitochondrial dysfunction, resulting in decreased efficiency of the electron transport chain and ATP production; 4) perturbation of the protein folding capacity of the endoplasmic reticulum (ER) (activating the unfolded protein response and inducing ER stress); and 5) decreased activity of cell survival kinases. The present review focuses on the direct cytotoxicity of RCM on proximal tubule cells in the absence of in vivo complications, such as alterations in renal hemodynamics or cytokine influence.

Analysis of the risk factors for contrast-induced nephropathy in over-aged patients receiving coronary intervention

Contrast-induced nephropathy has been the common cause of hospital-acquired acute kidney injury in the elderly patients. This study aimed to analyze the risk factors for contrast-induced nephropathy in over-aged patients undergoing coronary angiography or percutaneous coronary intervention. A total of 470 over-aged patients (≥80 years old) were judged as the contrast-induced nephropathy group ( n = 46) and non-contrast-induced nephropathy group ( n = 424) according to the postoperative 48-h serum creatinine levels. The patients' clinical information such as hypertension grade, number and degree of coronary artery stenosis, and death rate was compared. The risk factors for contrast-induced nephropathy were also analyzed. The hypertension grade in the contrast-induced nephropathy group was significantly higher than that in the non-contrast-induced nephropathy group ( P = 0.004). The degree of coronary artery stenosis was significantly more in the contrast-induced nephropathy group compared with the non-contrast-induced nephropathy group ( P = 0.003). The death rate of the contrast-induced nephropathy group (15.8%) was significantly higher than that of the non-contrast-induced nephropathy group (0.6%; P = 0.000). The percentage of patients with abnormal urine microalbumin was significantly bigger in the contrast-induced nephropathy group (62.5%) when comparing to the non-contrast-induced nephropathy group (23.6%; P = 0.00). Besides, there was also significant difference in the emergency/selective operation between the contrast-induced nephropathy group and non-contrast-induced nephropathy group ( P = 0.001). Further, hypertension grade ( P = 0.019), emergency/selective operation ( P = 0.025), degree of coronary artery stenosis ( P = 0.038), eGFR ( P = 0.034), and urine microalbumin ( P = 0.005) were the risk factors for contrast-induced nephropathy. Hypertension grade, emergency/selective operation, degree of coronary artery stenosis, eGFR, and urine microalbumin were the risk factors for contrast-induced nephropathy in over-aged patients receiving coronary angiography and percutaneous coronary intervention, providing guidance for the clinical prevention of contrast-induced nephropathy. Impact statement In this work, we evaluated the risk factors for contrast-induced nephropathy (CIN) in over-aged patients receiving coronary angiography (CAG) and percutaneous coronary intervention (PCI). We found that hypertension grade, emergency/selective operation, degree of coronary artery stenosis, eGFR, and urine microalbumin were the risk factors for CIN in over-aged patients receiving CAG and PCI. This study provides guidance for the clinical prevention of CIN in over-aged patients undergoing coronary intervention, highlighting that a perioperative comprehensive management strategy is needed to improve the prognosis.

Risk of renal events following intravenous iodinated contrast material administration among inpatients admitted with cancer a retrospective hospital claims analysis

BACKGROUND

There is little published evidence examining the use of contrast material (CM) and the risk of acute renal adverse events (AEs) in individuals with increasingly common risk factors including cancer and chronic kidney disease (CKD). The objective of this study was to use real world hospital data to test the hypothesis that inpatients with cancer having CT procedures with iodinated CM would have higher rates of acute renal AEs in comparison to inpatients without cancer.

METHODS

Inpatient hospital visits in the Premier Hospital Database from January 1, 2010 through September 30, 2015 were eligible for inclusion. The outcome of interest was a composite of acute renal AEs including: acute kidney injury, acute renal failure requiring dialysis, contrast induced-acute kidney injury and renal failure. Multivariable models, adjusted for differences in patient demographics and comorbid conditions, were used to estimate the incremental risk of acute renal AEs by CT (with or without iodinated CM), CKD stage and type of cancer.

RESULTS

Among 29,850,475 inpatient visits across 611 hospitals, 7.4% had record of a CT scan, 5.9% had CKD, and 3.4% had the primary diagnosis of cancer. The baseline risk for an acute renal AE in patients without cancer or CKD and no CT or CM was 0.5%. The absolute risk increases from baseline by 0.2% with a CT and by 0.8% with iodinated CM. Patients with CKD having a CT scan with iodinated CM have an absolute risk of 4.1 to 9.7% depending on the stage of CKD. For patients with cancer, the absolute risk increases, varying from 0.3 to 2.3% depending on the type of cancer.

CONCLUSIONS

Inpatients with cancer are at higher likelihood of developing acute renal AEs following CT with iodinated CM compared to those without a cancer. Understanding the underlying risks of acute renal AEs among complex inpatient admissions is an important consideration in treatment choices for oncology patients.

Iodine-based contrast media, multiple myeloma and monoclonal gammopathies: literature review and ESUR Contrast Media Safety Committee guidelines

Objectives

Many radiologists and clinicians still consider multiple myeloma (MM) and monoclonal gammopathies (MG) a contraindication for using iodine-based contrast media. The ESUR Contrast Media Safety Committee performed a systematic review of the incidence of post-contrast acute kidney injury (PC-AKI) in these patients.

Methods

A systematic search in Medline and Scopus databases was performed for renal function deterioration studies in patients with MM or MG following administration of iodine-based contrast media. Data collection and analysis were performed according to the PRISMA statement 2009. Eligibility criteria and methods of analysis were specified in advance. Cohort and case-control studies reporting changes in renal function were included.

Results

Thirteen studies were selected that reported 824 iodine-based contrast medium administrations in 642 patients with MM or MG, in which 12 unconfounded cases of PC-AKI were found (1.6 %). The majority of patients had intravenous urography with high osmolality ionic contrast media after preparatory dehydration and purgation.

Conclusions

MM and MG alone are not risk factors for PC-AKI. However, the risk of PC-AKI may become significant in dehydrated patients with impaired renal function. Hypercalcaemia may increase the risk of kidney damage, and should be corrected before contrast medium administration. Assessment for Bence-Jones proteinuria is not necessary.

Key Points

• Monoclonal gammopathies including multiple myeloma are a large spectrum of disorders.

• In monoclonal gammopathy with normal renal function, PC-AKI risk is not increased.

• Renal function is often reduced in myeloma, increasing the risk of PC-AKI.

• Correction of hypercalcaemia is necessary in myeloma before iodine-based contrast medium administration.

• Bence-Jones proteinuria assessment in myeloma is unnecessary before iodine-based contrast medium administration.

Imaging of Multiple Myeloma

Multiple myeloma is the most common bone malignancy. Imaging plays an important role in identifying the extent of the disease, disease process, guiding biopsies, and diagnosing associated spinal and intracranial complications. Multiple myeloma and related plasma cell proliferative disorders have a diverse set of clinicopathologic findings and on neuroimaging present unique and diverse findings from the disease and from complications of the disease and treatment, which are valuable for clinicians and radiologists.

Clinical observation of adverse drug reactions to non-ionic iodinated contrast media in population with underlying diseases and risk factors

OBJECTIVE

To determine the adverse drug reaction (ADR) profile of non-ionic iodinated contrast media in populations with underlying diseases and risk factors and to provide guidance for more safe and rational use of iodinated contrast media (ICMs) in the clinic.

METHODS

Data from 120,822 cases who underwent enhanced CT examination in our hospital from January 2014 to March 2016 were collected. A standardized case report form was used for data collection and analysis.

RESULTS

The incidence of ADRs was 0.4% and 0.44% in patients with and without underlying diseases, respectively (p = 0.378). Risk factor analysis revealed that patients with asthma had the highest incidence of ADRs, followed by patients with cardiac insufficiency and patients who were aged had the lowest incidence. There was a low incidence of ADRs in patients under metformin (0.36%) and β-adrenaline receptor antagonist (0.20%) medication. The incidence was the highest in patients with previous ADRs to ICMs (7.17%) and the lowest in those with a history of ICM usage but no previous reactions (0.32%). ADRs were more common in patients at high risk at a higher injection dose (≥100 ml; p < 0.01) and speed (≥5 ml s^-1; p < 0.01).

CONCLUSION

The incidence of ADRs was extremely low in patients regardless of underlying diseases. Some high-risk factors have certain correlations with the occurrence of ADRs. Particular attention should be given to patients at high risk when performing enhanced CT examination. Advances in knowledge: The correlation between various risk factors and underlying diseases and ADRs was comprehensively analyzed in a large-scale population.

The High Risk of Contrast-induced Nephropathy in Patients with Suspected Pulmonary Embolism Despite Three Different Prophylaxis: A Randomized Controlled Trial

OBJECTIVE

The objective was to compare the protective effects of N-acetylcysteine (NAC) plus normal saline (NS), sodium bicarbonate (NaHCO₃ ) plus NS, and NS alone in the prevention of contrast-induced nephropathy (CIN) after computed tomography pulmonary angiography (CTPA) in emergency patients.

METHODS

This study was planned as a randomized, controlled clinical research. Patients undergoing contrast-enhanced CTPA on suspicion of pulmonary embolism (PE) in the emergency department and with at least one risk factor for development of CIN were included in one of three different prophylaxis groups. The groups received 3 mL/kg intravenous (IV) NAC+NS or NaHCO₃ +NS solution or NS alone 1 hour before CTPA and 1 mL/kg IV per hour for a minimum of 6 hours after CTPA. CIN was evaluated as the primary outcome and moderate or severe renal insufficiency and in-hospital mortality as secondary outcomes.

RESULTS

A total of 257 patients were enrolled in the study. The total level of CIN development was 23.7% (61/257), the level of moderate and severe renal failure was 12.5% (32/257), and the in-hospital mortality rate was 12.8% (33/257). Rates of CIN development in the drug groups were 23.5% in the NAC group (20/85), 21.2% (18/85) in the NaHCO₃ group, and 26.4% in the NS group (23/87). Rates of development of moderate or severe renal insufficiency were 9.4% in the NAC group (8/85), 10.6% in the NaHCO₃ group (9/85), and 17.2% in the NS group (15/87). In-hospital mortality rates were 12.9% in the NAC group (11/85), 11.8% in the NaHCO₃ group (10/85), and 13.8% in the NS group (12/87). No difference was determined between the drug groups in terms of CIN, moderate or severe renal injury, or hospital mortality.

CONCLUSIONS

Our results indicate that there is a high risk of CIN in patients with suspected PE despite three different types of prophylaxis being administered, and no statistically significant differences were observed among prophylactic NAC, NaHCO₃ , and NS in prevention of CIN following contrast-enhanced CTPA.

Estimating the Risk of Radiocontrast-Associated Nephropathy

Estimates of the incidence of radiocontrast-associated nephropathy vary widely and suffer from misclassification of the cause of AKI and confounding. Using the Nationwide Inpatient Sample, we created multiple estimates of the risk of radiocontrast-associated nephropathy among adult patients hospitalized in the United States in 2009. First, we stratified patients according to the presence or absence of 12 relatively common diagnoses associated with AKI and evaluated the rate of AKI between strata. Next, we created a logistic regression model, controlling for comorbidity and acuity of illness, to estimate the risk of AKI associated with radiocontrast administration within each stratum. Finally, we performed an analysis stratified by the degree of preexisting comorbidity. In general, patients who received radiocontrast did not develop AKI at a clinically significant higher rate. Adjusted only for the complex survey design, patients to whom radiocontrast was and was not administered developed AKI at rates of 5.5% and 5.6%, respectively. After controlling for comorbidity and acuity of illness, radiocontrast administration associated with an odds ratio for AKI of 0.93 (95% confidence interval, 0.88 to 0.97). In conclusion, the risk of radiocontrast-associated nephropathy may be overstated in the literature and overestimated by clinicians. More accurate AKI risk estimates may improve clinical decision-making when attempting to balance the potential benefits of radiocontrast-enhanced imaging and the risk of AKI.

The potential use of biomarkers in predicting contrast-induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI) is a problem associated with the use of iodinated contrast media, causing kidney dysfunction in patients with preexisting renal failure. It accounts for 12% of all hospital-acquired kidney failure and increases the length of hospitalization, a situation that is worsening with increasing numbers of patients with comorbidities, including those requiring cardiovascular interventional procedures. So far, its diagnosis has relied upon the rise in creatinine levels, which is a late marker of kidney damage and is believed to be inadequate. Therefore, there is an urgent need for biomarkers that can detect CI-AKI sooner and more reliably. In recent years, many new biomarkers have been characterized for AKI, and these are discussed particularly with their use in known CI-AKI models and studies and include neutrophil gelatinase-associated lipocalin, cystatin C (Cys-C), kidney injury molecule-1, interleukin-18, N-acetyl-β-d-glucosaminidase, and L-type fatty acid-binding protein (L-FABP). The potential of miRNA and metabolomic technology is also mentioned. Early detection of CI-AKI may lead to early intervention and therefore improve patient outcome, and in future any one or a combination of several of these markers together with development in technology for their analysis may prove effective in this respect.

Contrast agents in diagnostic imaging: Present and future

Specific contrast agents have been developed for x ray examinations (mainly CT), sonography and Magnetic Resonance Imaging. Most of them are extracellular agents which create different enhancement on basis of different vascularization or on basis of different interstitial network in tissues, but some can be targeted to a particular cell line (e.g. hepatocyte). Microbubbles can be used as carrier for therapeutic drugs which can be released in specific targets under sonographic guidance, decreasing systemic toxicity and increasing therapeutic effect. Radiologists have to choose a particular contrast agent knowing its physical and chemical properties and the possibility of adverse reactions and balancing them with the clinical benefits of a more accurate diagnosis. As for any drug, contrast agents can cause adverse events, which are more frequent with Iodine based CA, but also with Gd based CA and even with sonographic contrast agents hypersensitivity reaction can occur.

Contrast-Enhanced Abdominal MRI for Suspected Appendicitis: How We Do It

OBJECTIVE

The purpose of this article is to describe our approach to contrast-enhanced abdominal MRI in patients with nontraumatic abdominal pain and suspected appendicitis. We aim to share our experience on the advantages, pearls, and pitfalls of MRI in this clinical setting, in comparison with CT and ultrasound.

CONCLUSION

We present some typical cases of appendicitis and alternative diagnoses in patients presenting with acute nontraumatic abdominal pain.

Intravenous Imaging Contrast Media Complications: The Basics That Every Clinician Needs to Know

Intravenous contrast is commonly used in noninvasive imaging procedures such as magnetic resonance imaging and computed tomography and can evaluate blood vessels and better characterize soft-tissue lesions. Although the incidence of adverse events after administration of contrast is low, it is important that clinicians and radiologists minimize risks and respond quickly and effectively when reactions occur. We will discuss a range of adverse events to iodinated and gadolinium-based contrast agents, including allergic-like reactions, nephrotoxicity, extravasation, and nephrogenic systemic fibrosis. We will review risk stratification for patients, as well as premedication and treatment of adverse events.

Acute kidney injury by radiographic contrast media: pathogenesis and prevention

It is well known that iodinated radiographic contrast media may cause kidney dysfunction, particularly in patients with preexisting renal impairment associated with diabetes. This dysfunction, when severe, will cause acute renal failure (ARF). We may define contrast-induced Acute Kidney Injury (AKI) as ARF occurring within 24-72 hrs after the intravascular injection of iodinated radiographic contrast media that cannot be attributed to other causes. The mechanisms underlying contrast media nephrotoxicity have not been fully elucidated and may be due to several factors, including renal ischaemia, particularly in the renal medulla, the formation of reactive oxygen species (ROS), reduction of nitric oxide (NO) production, and tubular epithelial and vascular endothelial injury. However, contrast-induced AKI can be prevented, but in order to do so, we need to know the risk factors. We have reviewed the risk factors for contrast-induced AKI and measures for its prevention, providing a long list of references enabling readers to deeply evaluate them both.

Side effects of radiographic contrast media: pathogenesis, risk factors, and prevention

Radiocontrast media (RCM) are medical drugs used to improve the visibility of internal organs and structures in X-ray based imaging techniques. They may have side effects ranging from itching to a life-threatening emergency, known as contrast-induced nephropathy (CIN). We define CIN as acute renal failure occurring within 24-72 hrs of exposure to RCM that cannot be attributed to other causes. It usually occurs in patients with preexisting renal impairment and diabetes. The mechanisms underlying CIN include reduction in medullary blood flow leading to hypoxia and direct tubule cell damage and the formation of reactive oxygen species. Identification of patients at high risk for CIN is important. We have reviewed the risk factors and procedures for prevention, providing a long list of references enabling readers a deep evaluation of them both. The first rule to follow in patients at risk of CIN undergoing radiographic procedure is monitoring renal function by measuring serum creatinine and calculating the eGFR before and once daily for 5 days after the procedure. It is advised to discontinue potentially nephrotoxic medications, to choose radiocontrast media at lowest dosage, and to encourage oral or intravenous hydration. In high-risk patients N-acetylcysteine may also be given.

Pathogenesis of renal failure in multiple myeloma: any role of contrast media?

The spectrum of kidney disease-associated monoclonal immunoglobulin and plasma cell malignancies is remarkably broad and encompasses nearly all nephropathologic entities. Multiple myeloma with kidney impairment at presentation is a medical emergency since the recovery of kidney function is associated with survival benefits. In most cases, kidney impairment may be the first clinical manifestation of malignant plasma cell dyscrasias like multiple myeloma and light chain amyloidosis. Multiple myeloma per se cannot be considered a main risk factor for developing acute kidney injury following intravascular administration of iodinated contrast media. The risk is increased by comorbidities such as chronic kidney disease, diabetes, hypercalcemia, dehydration, and use of nephrotoxic drugs. Before the administration of contrast media, the current recommended laboratory tests for assessing kidney function are serum creatinine measurement and the estimation of glomerular filtration rate by using the CKD-EPI equation. The assessment of Bence Jones proteinuria is unnecessary for evaluating the risk of kidney failure in patients with multiple myeloma, since this test cannot be considered a surrogate biomarker of kidney function.

How to reduce nephropathy following contrast-enhanced CT: a lesson in policy implementation

In excess of 50 contrast-enhanced computed tomography (CT) examinations are typically undertaken in our tertiary hospital NHS Trust each weekday, approximately 13,000 each year. In the Department of Radiology alone, we inject more than 1300 l of iodinated contrast medium per annum. There is a real need to devise a policy to anticipate contrast medium-induced nephropathy (CIN) and minimize its effects, without disrupting the high-intensity CT service. Having written a comprehensive yet pragmatic policy to reduce the incidence of this iatrogenic condition, it seemed sensible to share it with the wider radiology community and share the experience and lessons learnt in engaging all the stakeholders, ushering in the change with as little fuss as possible. The ramifications on primary and secondary care had to be anticipated, resource implications managed, and staff trained. This review is therefore presented in four sections: framing the problem, assessing its size and nature; a succeeding section on the available guidelines and their uptake; the policy itself to reduce CIN in CT is presented in the third section; and crucially, a description of the policy introduction process in the last section.