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Since its introduction more than 35 years ago, gadolinium-enhanced MRI has fundamentally changed medical practice. Although extraordinarily safe, gadolinium-based contrast agents (GBCAs) may have side effects. Four distinct safety considerations include acute allergiclike reactions, nephrogenic systemic fibrosis (NSF), gadolinium deposition, and symptoms associated with gadolinium exposure. Acute reactions after GBCA administration are uncommon-far less than with iodinated contrast agents-and, although rare, serious reactions can occur. NSF is a rare but serious sclerodermalike condition occurring in patients with kidney failure after exposure to American College of Radiology (ACR) group I GBCAs. Group II and III GBCAs are considered lower risk, and, through their use, NSF has largely been eliminated. Unrelated to NSF, retention of trace amounts of gadolinium in the brain and other organs has been recognized for over a decade. Deposition occurs with all agents, although linear agents appear to deposit more than macrocyclic agents. Importantly, to date, no data show any adverse biologic or clinical effects from gadolinium deposition, even with normal kidney function. This article summarizes the latest safety evidence of commercially available GBCAs with a focus on new agents, discusses updates to the ACR NSF GBCA safety classifications, and describes approaches for strengthening the evidence needed for regulatory decisions.

Adverse reactions to contrast media, although uncommon, are often high-acuity events and potentially life-threatening. Nonetheless, these events are treatable, and radiologists may be called on to manage a contrast media reaction. However, because these events are infrequent, they are prone to management errors. This Special Series Review highlights common pitfalls and practical tips for the management of acute contrast media reactions in children and adults. Recognition of frequent management errors and implementation of the mitigation strategies presented can ameliorate risk and improve patient outcomes. These measures include proper training regarding reaction management and medication administration, the prompt use of intramuscular epinephrine autoinjectors whenever a severe allergic-like reaction is suspected, the use of visual aids for quick reference in the setting of a reaction, and the recognition of adverse events that are not allergic-like reactions, which commonly require only supportive care.

Iodinated contrast material (ICM) has revolutionized the field of diagnostic radiology through improvements in diagnostic performance and the expansion of clinical indications for radiographic and CT examinations. Historically, nephrotoxicity was a feared complication of ICM use, thought to be associated with a significant risk of morbidity and mortality. Such fears often precluded the use of ICM in imaging evaluations, commonly at the expense of diagnostic performance and timely diagnosis. Over the past 20 years, the nephrotoxic risk of ICM has become a topic of debate, as more recent evidence from higher-quality studies now suggests that many cases of what was considered contrast-induced acute kidney injury (CI-AKI) likely were cases of mistaken causal attribution; most of these cases represented either acute kidney injury (AKI) caused by any of myriad other known factors that can adversely affect renal function and were coincidentally present at the time of contrast media exposure (termed "contrast-associated AKI" [CA-AKI]) or a manifestation of the normal variation in renal function that increases with worsening renal function. This Special Series Review discusses the current state of knowledge regarding CI-AKI and CA-AKI, including the incidence, risk factors, outcomes, and prophylactic strategies in the identification and management of these clinical conditions.

BACKGROUND. Patients with cancer undergo frequent CT examinations with iodinated contrast media and may be uniquely predisposed to contrast-associated acute kidney injury (CA-AKI). OBJECTIVE. The purpose of this study was to develop and validate a model for predicting the risk of CA-AKI after contrast-enhanced CT in patients with cancer. METHODS. This retrospective study included 25,184 adult patients (12,153 men, 13,031 women; mean age, 62.3 ± 13.7 [SD] years) with cancer who underwent 46,593 contrast-enhanced CT examinations between January 1, 2016, and June 20, 2020, at one of three academic medical centers. Information was recorded regarding demographics, malignancy type, medication use, baseline laboratory values, and comorbid conditions. CA-AKI was defined as a 0.3-mg/dL or greater increase in serum creatinine level from baseline within 48 hours after CT or a 1.5-fold or greater increase in the peak measurement within 14 days after CT. Multivariable models accounting for correlated data were used to identify risk factors for CA-AKI. A risk score for predicting CA-AKI was generated in a development set ( n = 30,926) and tested in a validation set ( n = 15,667). RESULTS. CA-AKI occurred after 5.8% (2682/46,593) of CT examinations. The final multivariable model for predicting CA-AKI included hematologic malignancy, diuretic use, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, chronic kidney disease (CKD) stage 3a, CKD stage 3b, CKD stage 4 or 5, serum albumin level less than 3.0 g/dL, platelet count less than 150 × 10 3 /μL, 1+ or greater proteinuria on baseline urinalysis, diabetes mellitus, heart failure, and contrast medium volume 100 mL or greater. A risk score (range, 0-53 points) was generated with these variables. The most points (13) were for CKD stage 4 or 5 and for albumin level less than 3 g/dL. The frequency of CA-AKI progressively increased in higher risk categories. For example, in the validation set, CA-AKI occurred after 2.2% of CT examinations in the lowest risk category (score ≤ 4) and after 32.7% of CT examinations in the highest risk category (score ≥ 30). The Hosmer-Lemeshow test result indicated that the risk score was a good fit ( p = .40). CONCLUSION. A risk model in which readily available clinical data are used to predict the likelihood of CA-AKI after contrast-enhanced CT in patients with cancer was developed and validated. CLINICAL IMPACT. The model may help facilitate appropriate implementation of preventive measures in the care of patients at high risk of CA-AKI.

On March 30, 2022, the U.S. FDA issued a drug safety communication recommending that infants and young children through 3 years of age undergo monitoring of thyroid function within 3 weeks of intravascular administration of iodine-based contrast media. This article considers the literature that was referenced for this decision and provides an outlook on thyroid monitoring after diagnostic imaging from pediatric radiology and pediatric endocrinology perspectives.

The aim of this study was to quantify the effect of iodinated contrast media (ICM) conservation measures implemented at a single health system during a global shortage, comparing the 12-month period before intervention and the 14-day period after intervention. The mean daily utilization of contrast-enhanced CT decreased from 112 to 44 examinations, the mean ICM volume per CECT examination decreased from 88 to 74 mL, and the mean daily ICM use decreased from 9.9 to 3.3 L.

Given the integral role of CT in patient care, the current global contrast media shortage creates profound and manifold patient care implications. We used a large insurance dataset to highlight examinations (abdominopelvic and chest CT), delivery settings (emergency department and outpatient hospital), and clinical indications (acute abdominopelvic and chest disease and cancer surveillance) for which contrast-enhanced CT is most commonly used. Such information may help inform emerging national guidelines and institutional policies.

An unanticipated but severe shortage in iodinated contrast media (ICM) is currently affecting imaging practices across the globe and is expected to persist through at least the end of June 2022. This supply shock may lead health care systems to experience an acute imaging crisis, given that many affected facilities have contrast agent supplies that are anticipated to last only a week or two under normal operating conditions. To maximize the opportunity to continue to provide optimal care for patients with emergent or life-threatening imaging indications and thereby minimize the overall impact on patient care, practice leaders will need to quickly assess their contrast material inventories, prioritize examination indications, and reduce their expected short-term usage of ICM. This Clinical Perspective reviews ICM conservation techniques that the Yale School of Medicine has deployed or is considering deploying, depending on the severity and length of the supply shortage.

BACKGROUND. MRI is the reference standard for neonatal brain imaging, but it is expensive, time-consuming, potentially limited by availability and accessibility, and contraindicated in some patients. Transfontanelle neonatal head ultrasound is an excellent alternative but may be less sensitive and specific than MRI. Contrast-enhanced ultrasound (CEUS) has the potential to improve the capabilities of ultrasound. OBJECTIVE. The purpose of this study is to prospectively evaluate the feasibility, safety, and diagnostic performance of transfontanelle neonatal brain CEUS, with MRI used as the reference standard. METHODS. Neonates in the institutional neonatal ICU who were undergoing MRI as part of their clinical care were prospectively recruited to undergo portable brain ultrasound and CEUS for research purposes. Brain ultrasound and CEUS were performed portably without moving the patient from the isolette or crib in the neonatal ICU. Adverse events were recorded. Two radiologists independently evaluated ultrasound and CEUS images for abnormalities and then reached consensus regarding discrepancies. A separate radiologist reviewed MRI examinations. Sensitivity, specificity, and interreader agreement were evaluated, with MRI used as the reference. Qualitative post hoc image review was performed. RESULTS. Twenty-six neonates (nine boys and 17 girls; mean [± SD] age, 15.2 ± 14.0 days) were included. No significant alteration in patient vital signs or adverse reaction to the ultrasound contrast agent (UCA) occurred. The mean duration of the examination was significantly shorter for combined ultrasound and CEUS than for MRI (21.1 ± 4.7 vs 74.2 ± 34.8 minutes; p < .001). Interrater agreement for any abnormality was almost perfect for both ultrasound and CEUS (κ = 0.92 and 0.85, respectively). Sensitivity for any abnormality was 86.7% for ultrasound and 93.3% for CEUS; specificity was 100.0% for both. CEUS had sensitivity of 87.5% for acute or subacute ischemia and 100.0% for chronic ischemia; its specificity was 100.0% for acute or subacute ischemia and chronic ischemia. For both ultrasound and CEUS, sensitivity for subdural and intraparenchymal hemorrhage was poor (22.2-50.0%). On CEUS but not on MRI, post hoc review showed a case of postischemic hyperperfusion, which was confirmed by subsequently performed contrast-enhanced CT. CONCLUSION. The use of portable brain CEUS in neonates is feasible, safe, and more rapid than MRI. CLINICAL IMPACT. The potential diagnostic utility of brain neonatal CEUS relative to conventional ultrasound, particularly for ischemia, warrants further investigation.

BACKGROUND. Extrinsic warming of iodinated CT contrast media to body temperature reduces viscosity and injection pressures. However, studies examining the effect of extrinsic warming on clinical adverse events are limited in number and provide conflicting results. Therefore, consensus practice recommendations have been sparse. OBJECTIVE. The purpose of this study is to compare rates of extravasation, allergic and allergiclike reactions, and physiologic reactions between iohexol 350 mg I/mL warmed to body temperature (37°C) versus this agent maintained at room temperature. METHODS. This retrospective study compared adult patients who received CT examinations using IV iohexol 350 that had either been warmed to body temperature or maintained at room temperature. At our institution, contrast media had historically been warmed to body temperature before a protocol change unrelated to this investigation. Information on the patient and CT examination was extracted from the electronic medical record. Adverse events, including extravasations, allergic and allergiclike reactions, and physiologic reactions, were compared between groups. RESULTS. A total of 3939 patients received contrast media warmed to body temperature before the protocol change; 3933 patients received contrast media at room temperature after the protocol change. The body temperature group experienced 11 (0.28%; 95% CI, 0.14-0.50%) adverse events, all extravasations; the allergic and allergic-like reaction rate was 0.00% (97.5% CI, 0.00-0.09%). The room temperature group experienced 17 (0.43%; 95% CI, 0.25-0.69%) adverse events: 13 (0.33%; 95% CI, 0.17-0.56%) extravasations and four (0.10%; 95% CI, 0.03-0.26%) allergic and allergiclike reactions. No physiologic reaction occurred in either group. The two groups were not different in terms of overall reaction rate ( p = .19), extravasation rate ( p = .69), allergic and allergiclike reaction rate ( p = .06), or physiologic reaction rate ( p > .99). Logistic regression adjusting for patient and CT characteristics (age, sex, conventional CT vs CTA, contrast media volume, injection location) showed no significant association of patient group and adverse reaction rate (odds ratio, 2.19; 95% CI, 0.68-7.00). Multivariable regression modeling showed an excess of 0.27 adverse events per 100 patients within the room temperature group, which is below a 0.6% noninferiority margin. CONCLUSION. The data suggest that maintaining iohexol 350 at room temperature is noninferior to warming the agent to body temperature before injection. CLINICAL IMPACT. The resources involved to prewarm iohexol 350 before injection may not be warranted.

Contrast-enhanced ultrasound (CEUS) utilization is expanding rapidly, particularly in children, in whom the modality offers the important advantages of dynamic evaluation of the vasculature, portability, lack of ionizing radiation, and lack of need for sedation. Accumulating data establish an excellent safety profile of ultrasound contrast agents (UCAs) in children. Although UCAs have been FDA-approved only for IV use in children for characterizing focal liver lesions and for use in children during echocardiography, off-label applications are expanding the diagnostic potential of ultrasound. Focal liver lesion evaluation is the most common use of CEUS, and the American College of Radiology Pediatric LI-RADS Working Group recommends including CEUS for evaluation of a newly discovered focal liver lesion in many circumstances. Data also support the role of CEUS in hemodynamically stable children with blunt abdominal trauma, and CEUS is becoming a potential alternative to CT in this setting. Additional potential applications that require further study include evaluation of pathology in the lung, spleen, brain, pancreas, bowel, kidney, female pelvis, and scrotum. This article explores the implementation of CEUS in children, describing basic principles of UCAs and CEUS technique and summarizing current and potential IV diagnostic applications based on pediatric-specific supporting evidence.

BACKGROUND. Incidences and risk factors for acute reactions to gadolinium-based contrast agents (GBCAs) are not fully understood, particularly in pediatric patients. OBJECTIVE. The purpose of this study was to retrospectively examine allergiclike and physiologic acute reactions in pediatric patients who receive GBCAs for MRI examinations. METHODS. The study cohort consisted of all pediatric patients (age < 18 years old) who underwent an MRI examination with a GBCA at our institution from June 1, 2009, to May 9, 2017. Acute reactions were identified by medical record review and classified by severity using the American College of Radiology guidelines. Potential risk factors for reactions were examined using generalized estimating equation methods accounting for rare events. RESULTS. A total of 16,237 GBCA injections (10,141 gadodiamide injections, 4880 gadobutrol injections, and 1216 gadobenate dimeglumine injections) were administered to a study cohort of 10,190 patients (49% [7982/16,237] girls and 51% [8255/16,237] boys). Incidences of 0.10% (17/16,237) for allergiclike and 0.14% (23/16,237) for physiologic reactions were observed. No severe reactions occurred. Allergiclike reaction incidences were significantly higher with gadobenate compared with gadodiamide (0.49% vs 0.04%; p < .001) and in patients who underwent abdominal or pelvic MRI examinations (0.38%) or cardiac examinations (0.55%) compared with head examinations (0.05%; p < .001 and p = .006, respectively). Physiologic reaction incidences were significantly higher in older patients (0.25% in patients 12-17 years old vs 0.03% in patients 2 to < 12 years old; p < .001) and in patients who underwent abdominal or pelvic examinations compared with head examinations (0.38% vs 0.10%; p = .002). Of 16 MRI examinations performed in patients with a prior allergiclike reaction to GBCAs, only one resulted in a repeat reaction. CONCLUSION. In this pediatric cohort, GBCA type, patient age, and MRI type were risk factors for acute reactions. Repeat reactions were rare. CLINICAL IMPACT. Providers must weigh the risks and benefits when choosing a particular GBCA to use in their practices and must consider multiple, potentially disparate risks associated with each GBCA.

OBJECTIVE. The purpose of this study was to determine whether contrast medium volume and method of administration and baseline estimated glomerular filtration rate influence the efficacy of prophylactic hydration for prevention of acute kidney injury after contrast administration. MATERIALS AND METHODS. An online search of PubMed conducted on August 25, 2017, produced a total of 697 studies. After the reports were reviewed, nine were included in this study. The extracted data on all patients in these studies were separated into a group that received prophylactic hydration and a group that did not. The following three parameters were used for subgroup analysis: contrast medium volume, contrast administration method, and baseline estimated glomerular filtration rate. The t test was performed, and study-level odds ratios with 95% CIs and p values were calculated. Tests of heterogeneity were conducted. RESULTS. When the volume of contrast agent administered exceeded 100 mL, hydration was beneficial in the prevention of contrast-induced acute kidney injury (odds ratio, 0.546). If the volume was less than 100 mL, hydration had no efficacy in preventing contrast-induced acute kidney injury (odds ratio, 0.917). Administration route and baseline estimated glomerular filtration rate exerted no effect on the efficacy of prophylactic hydration. CONCLUSION. For patients who receive less than 100 mL of contrast medium, the prevalent practice for contrast-enhanced CT studies, prophylactic hydration may not be necessary, regardless of the estimated glomerular filtration rate or route of contrast administration. For patients undergoing procedures requiring administration of large volumes of contrast medium, however, hydration is recommended to prevent contrast-induced acute kidney injury.

OBJECTIVE. The objective of this article is to review strategies to reduce the use of gadolinium-based contrast agents for pediatric abdominal MRI. CONCLUSION. Alternative contrast agents that do not contain gadolinium and unenhanced pediatric abdominal MRI protocols have shown clinical utility. Sequences such as DWI and new multicontrast MRI pulse sequences offer promise for tissue characterization without IV contrast agents. Patients requiring repeat MRI to evaluate for change in focal disease can be monitored with unenhanced abdominal MRI.

OBJECTIVE. Myelography is a commonly used procedure to evaluate the spinal canal. However, the procedure is not without risk, chiefly risk of seizure after intrathecal administration of iodinated contrast material. CONCLUSION. The risk of seizure remains an important concern for radiologists, who should strongly consider practice parameter guidelines that address this risk.

OBJECTIVE. The purpose of this article is to describe the risk-benefit balance of contrast-enhanced breast MRI (CE-BMRI) screening. CONCLUSION. CE-BMRI confers risk of effects associated with administration of gadolinium-based contrast agents (GBCAs), including nephrogenic systemic fibrosis and gadolinium retention. The risk-benefit balance of CE-BMRI screening is favorable for carriers of BRCA , TP53 , or other deleterious mutations women who have undergone thoracic irradiation; and women at 20% or greater lifetime risk of breast cancer. The balance is uncertain, however, for women at intermediate to average risk. Women must always receive detailed information regarding possible GBCA-associated effects.

OBJECTIVE. Adverse drug reactions (ADRs) to radiocontrast media are a significant social and economic burden and are difficult to predict. Because some ADRs to radiocontrast media may be immunologically induced, a skin test with diluted 1:10 radiocontrast media has been used to predict ADRs. However, using this test in clinical practice is difficult because of its low sensitivity. SUBJECTS AND METHODS. This study enrolled 36 patients with a history of immediate ADR to radiocontrast media who visited the Allergy and Asthma Clinic of Severance Hospital from 2017 to 2018. Patients underwent intradermal testing (IDT) with five types of diluted (1:10) and undiluted radiocontrast media (iohexol, iobitridol, iopamidol, iopromide, and iodixanol). The IDT result was regarded as positive if at least one radiocontrast medium elicited a positive reaction. Positivity of IDT and sensitivity to the culprit radiocontrast medium were calculated and compared. For subsequent CT examinations with a radiocontrast medium, the contrast agent eliciting a negative skin reaction in IDT was selected, excluding the previous culprit radiocontrast medium. RESULTS. IDT positivity and sensitivity for the culprit radiocontrast medium at 1:10 dilution were 47.2% and 47.2%, respectively, whereas the positivity and sensitivity for the undiluted radiocontrast medium were 86.1% and 75.0%, respectively. The positivity and sensitivity were higher with frequent radiocontrast medium use or with severe reaction. Of 22 patients who underwent another CT examination with the contrast medium selected on the basis of IDT results, 21 (95.5%) did not experience an ADR. CONCLUSION. IDT to prevent ADR should be performed with undiluted radiocontrast medium. Selecting an alternative radiocontrast agent on the basis of IDT results can be clinically useful to prevent recurrent ADRs to radiocontrast media.

OBJECTIVE. The objective of our study was to explore whether clinical factors historically associated with contrast material-causative kidney injury (contrast-induced nephrotoxicity [CIN]) increase risk after use of IV iodinated low-osmolality contrast material (LOCM) in patients with stage IIIb-V chronic kidney disease. MATERIALS AND METHODS. In this retrospective hypothesis-generating study, 1:1 propensity score matching was used to assess post-CT acute kidney injury (AKI) after unenhanced or contrast-enhanced CT in patients with stable estimated glomerular filtration rate (eGFR; 1112 patients with an eGFR = 30-44 mL/min/1.73 m 2 and 86 patients with an eGFR < 30 mL/min/1.73 m 2 and no dialysis). Historical risk factors including diabetes mellitus, age more than 60 years, hypertension, loop diuretic use, hydrochlorothiazide use, and cardiovascular disease were evaluated for modulation of CIN risk. Stepwise multivariable logistic regression was performed. RESULTS. Overall IV LOCM was an independent risk factor for post-CT AKI in patients with an eGFR of less than 30 mL/min/1.73 m 2 (odds ratio, 3.96 [95% CI, 1.29-12.21]; p = 0.016) but not in those with an eGFR of 30-44 mL/min/1.73 m 2 ( p = 0.24). In patients with an eGFR of less than 30 mL/min/1.73 m 2 , the tested covariates did not significantly modify the risk of CIN ( p = 0.096-0.832). In patients with an eGFR of 30-44 mL/min/1.73 m 2 , risk of CIN emerged in those with cardiovascular disease ( p = 0.015; number needed to harm from LOCM = 11 patients); the other tested cofactors had no significant effect ( p = 0.108-0.822). CONCLUSION. CIN was observed when eGFR was less than 30 mL/min/1.73 m 2 . In those with an eGFR of 30-44 mL/min/1.73 m 2 , CIN was not observed with LOCM alone but was observed in the presence of cardiovascular disease. Other cofactors historically thought to increase CIN risk (e.g., diabetes mellitus) did not increase risk of CIN. Further study is needed to determine whether these exploratory results are true associations.

OBJECTIVE. Contrast-induced nephropathy (CIN) generally is the main concern for patients with chronic kidney disease (CKD) undergoing contrast-enhanced imaging. To evaluate the risk of nephropathy induced by IV contrast medium (CM) in patients with CKD, we performed a meta-analysis. MATERIALS AND METHODS. We searched for PubMed and MEDLINE articles that were published up to October 3, 2018, contained the phrase "contrast medium" or "contrast media" and the word "renal," and included patients with CKD and a proper control group. The publications that were identified were reviewed, and only studies that used an IV route of CM administration were selected. Subgroup analysis was performed according to the estimated glomerular filtration rate. RESULTS. Six studies including 55,963 participants were selected. The Peto method and random-effects model were applied. IV infusion of CM did not lead to the deterioration of renal function in patients with CKD compared with those without CKD (odds ratio [OR], 1.07; 95% CI, 0.98-1.17; I 2 , 35.3%). As the estimated glomerular filtration rate decreased, fewer patients received IV CM. The ORs for CIN on the basis of CKD stage were as follows: 1.11 (95% CI, 0.95-1.30; I 2 , 4.0%) for stage 2 CKD, 1.05 (95% CI, 0.93-1.18, I 2 , 48.3%) for CKD lower than stage 3, 1.06 (95% CI, 0.94-1.19; I 2 , 32.0%) for stage 3 CKD, 1.08 (95% CI, 0.84-1.39; I 2 , 44.6%) for CKD lower than stage 4, 0.86 (95% CI, 0.37-2.00) for stage 4 CKD, and 0.26 (95% CI, 0.02-3.4) for stage 5 CKD in one study only. All analyses showed the lack of difference in the ORs for CIN between participants who received IV injection of CM and those who did not. CONCLUSION. Retrospective cohort studies of IV radiographic CM have failed to show renal damage in patients with CKD. This retrospective study is limited, and other risk factors for CIN might not be distributed evenly.

OBJECTIVE. The purpose of this study is to investigate the contributing effect of contrast media (CM) iodine dose on radiation-induced DNA damage in blood lymphocytes during a cardiac CT scan. MATERIALS AND METHODS. The minipigs were exposed 12 times in total to a fixed cardiac CT scan protocol. An unenhanced and two CM injection protocols were considered, the latter with 50% saline diluted (160 mg I/mL) and standard iodixanol. Blood samples were collected before and after CT, and radiation-induced DNA double-strand breaks were assessed using γ-H2AX (H2A histone family member X) immunofluorescent staining of the blood lymphocytes. Significant differences in foci numbers were investigated with an independent sample t test. In addition, a numeric dosimetry model was applied that simulates the cardiac CT scan, with the heart represented by a blood volume containing a mixture of six iodine concentrations (0, 10, 20, 30, 40, and 50 mg I/mL). RESULTS. Compared with the unenhanced (0 mg I/mL) protocol, the number of γ-H2AX foci per cell increased significantly ( p < 0.038), by 56.1% for the reduced iodine dose (160 mg I/mL) and by 141.1% for the standard iodine dose (320 mg I/mL) protocols. These in vivo results are confirmed by the dosimetry simulation model, in which 78.8% and 133.7% increases in locally absorbed blood dose in the left ventricle were observed for the reduced and standard iodine dose protocols, respectively. CONCLUSION. Administration of CM during a cardiac CT examination significantly increases radiation-induced DNA damage in blood lymphocytes. Moreover, a lower CM iodine dose results in a reduced level of DNA damage, at constant radiation exposure.

Objective: Adverse reactions to contrast media are potentially life-threatening events that require prompt recognition and management by radiologists who may have little experience with them. The objectives of this project were to develop and assess a simulation-based program that would equip radiology trainees with appropriate knowledge and skills to recognize and manage adverse contrast media reactions., Materials and Methods: Fifteen adverse contrast media reaction scenarios were developed to run on high-fidelity adult and pediatric mannequins in a simulation center. Ninety-six radiology trainees (postgraduate year 2-6) participated in the program, which consisted of two didactic lectures and a simulation session. For each simulation session, seven scenarios were chosen. Objective quizzes assessing knowledge and subjective questionnaires assessing comfort were completed both before and after the simulation. A survey assessing the overall program was also completed., Results: All 96 radiology trainees viewed the didactic lectures, attended a simulation session, and completed the pre- and postsimulation quizzes and questionnaires. Mean scores increased from 69% to 82% (p < 0.001) and from 3.1 to 4.5 out of 5 (p < 0.001) on the objective and subjective tests, respectively. Statistically significant improvement was also seen when participants were separated according to level of training. On the final program evaluation survey, scores ranged from 4.5 to 4.7 out of 5., Conclusion: We describe the development of a high-fidelity simulation program with a larger variety of scenarios than in prior studies that can provide radiologists the knowledge and skills needed to recognize and manage adverse contrast media reactions. We saw a statistically significant improvement in knowledge and comfort levels across all levels of training.

Objective: The purpose of this study was to compare management of moderate-severity reactions with and without a visual aid or flowchart in contrast medium reaction simulations., Subjects and Methods: All attending radiologists and trainees were requested to participate in a contrast medium reaction simulation program, including a moderate-severity reaction scenario, and were randomized to groups having or not having a visual aid. The time to administer intramuscular (IM) epinephrine via automated injector and errors in administration were recorded. After the simulation, all participants completed a survey assessing their comfort in treating reactions to contrast media with and without a visual aid., Results: A total of 138 participants were divided into 21 sessions in the program, with 68 participants in the moderate-severity reaction scenario. Eleven groups were provided a visual aid; 10 groups were not. Errors in management occurred in 18.2% (2 of 11) of groups with visual aids versus 40% (4 of 10) in groups without (p = 0.35), with epinephrine self-administration reflecting the most common error. Excluding the groups with errors, the mean time to administration of IM epinephrine was 97 seconds with versus 152 seconds without the visual aid (p = 0.04). Of the 138 participants, 97.8% agreed that the poster would aid in medication administration, and 87% agreed that it would help decrease time to administer medications., Conclusion: A visual aid increased the subjective confidence of radiologists in the dose and route of medication administration in the contrast medium reaction simulation and led to faster administration of epinephrine. Self-administration IM epinephrine errors were common and seen in both groups.

Objective: Controversy exists regarding the causal relationship between contrast media administration and the development of acute kidney injury because prospective randomized controlled trials (RCTs) confirming this relationship are lacking. In this systematic review we address studies using propensity score matching with regard to contrast-induced acute kidney injury and possible implications for future practice guideline development., Conclusion: Propensity score matching can overcome the main limitations of conventional observational studies and could serve as an alternative in the absence of RCTs.

Objective: The purpose of this article is to assess the performance of a contrast reaction management checklist for optimal management of a contrast reaction scenario created using a high-fidelity hands-on simulation., Materials and Methods: A safety checklist was designed that presented the five adverse events that most commonly occur after administration of IV contrast medium as well as their step-by-step management. Forty-three radiology residents were randomized into two groups, a checklist group (n = 22) and a control group (n = 21), as stratified by postgraduate year. Participants took written tests involving multiple-choice questions 2 months before and immediately after participating in the high-fidelity simulation scenario, which was videotaped and independently evaluated by three graders., Results: Both groups had similar scores on the multiple-choice question tests taken before and after participation in the simulation (p = 0.35 and p = 0.62, respectively). In the simulation, the checklist group scored significantly higher than the control group with regard to their overall management of a severe contrast reaction (85.1% vs 64.8%; p = 0.001), including individual scores for first-line treatment of bronchospasm (97.0% vs 91.3%; p = 0.035) and use of the correct route of administration and dose of epinephrine (77.3% vs 45.2%; p = 0.021)., Conclusion: A standardized contrast reaction management checklist can reduce the number of treatment errors that occur during a simulated severe contrast reaction, particularly with regard to proper administration of epinephrine and treatment of bronchospasm. Such a checklist could be used by radiologists, technologists, and nurses to improve patient safety as a result of improved contrast reaction management and teamwork skills.

Objective: Most diagnostic imaging centers ask patients to fast for 4-6 hours before contrast-enhanced CT. Previous studies have shown that prolonged fasting can be harmful. In addition, manufacturers of contrast agents claim that there is no special preparation needed before examination. The aim of this study was to evaluate the effects of preparative fasting on contrast-enhanced CT at a cancer center., Subjects and Methods: Outpatients (n = 3206) were prospectively evaluated and randomly assigned to two groups: the 1619 patients in group 1 fasted for at least 4 hours before the examination, whereas the 1587 patients in group 2 received a light meal. Adverse symptoms observed before and after contrast agent administration were compared between groups., Results: Adverse symptoms occurring after IV contrast agent administration were reported by 45 patients (1.5%) in group 1 and 30 patients (0.9%) in group 2. The most common symptoms were nausea (n = 32), weakness (n = 12), and vomiting (n = 5). The frequency of symptoms did not differ statistically significantly between groups (p > 0.05)., Conclusion: In this sample of patients with cancer undergoing contrast-enhanced CT, very few adverse symptoms were reported regardless of preparative fasting. These results support the idea that preparation for contrast-enhanced CT can be simplified, decreasing the discomfort and inconvenience experienced by patients.

Objective: The objective or our study was to assess the incidence rate and clinical characteristics of allergiclike reactions in patients who received both nonionic iodinated contrast medium (ICM) and gadolinium-based contrast medium (GBCM)., Materials and Methods: Acute allergiclike reactions in patients who received both ICM and GBCM to nonionic ICM or GBCM injections during a 5-year period were analyzed. Allergy preparation was not administered when patients received a different type of contrast material. Acute allergiclike reactions to both ICM and GBCM were evaluated., Results: Of 302,858 contrast injections (155,234 ICM and 147,624 GBCM) during a 5-year period, 1006 (752 ICM and 254 GBCM) acute allergiclike contrast reactions were reported. The overall rate of reaction to ICM was 0.48% (95% CI, 0.45-0.52%), and the overall rate of reaction to GBCM was 0.17% (95% CI, 0.15-0.19%). A total of 19,237 patients received at least one ICM injection and one GBCM injection, with a total of 56,310 injections (19,237 initial injections and 37,073 subsequent injections). Nine patients had reactions to both ICM and GBCM with the primary reaction rate of 9/19,237 (incidence rate, 0.047%; 95% CI, 0.044-0.050%), and the secondary reaction rate of 9/37,073 (incidence rate, 0.024%; 95% CI, 0.023-0.026%). All secondary reactions in patients who had a reaction to both ICM and GBCM were mild. None of the patients required medication for the treatment of the secondary reaction., Conclusion: An allergiclike reaction to both nonionic ICM and GBCM was an extremely rare event that presented as a mild acute reaction without significant clinical consequences despite the fact that an allergy preparation was not administered.

Objective: Given the rarity of contrast reactions in practice, most radiologists have little to no experience in their management, and errors are common. The purpose of this study was to compare treatment of a moderate-severity reaction with intramuscular epinephrine by either the traditional manual method of drawing up and delivering epinephrine with a needle and syringe or the use of an epinephrine autoinjector., Subjects and Methods: All diagnostic radiologists at the study institution were requested to participate in an annual contrast reaction simulation program, which consisted of three simulation scenarios in a high-fidelity simulation laboratory. During the moderate-severity simulation scenario, the time to administer intramuscular epinephrine and any errors in administration were recorded. Groups were randomized to use an autoinjector device or manual delivery. All participants completed a survey assessing the experience with epinephrine and their comfort in treating contrast reactions using a traditional manual approach versus an epinephrine autoinjector., Results: Among 189 participants in the contrast reaction simulation program, 76 participated in a moderate-severity reaction simulation two to five at a time in 25 sessions. Mean total time to administration was significantly longer for manual (108.8 seconds) than for autoinjector (38.7 seconds) delivery (p < 0.001). There were 11 errors in the manual group and one error in the autoinjector group (p = 0.005). Ninety-four percent of participants reported feeling very comfortable or comfortable with the autoinjector as opposed to 60% for manual delivery (p < 0.001). Overall, 96% of participants thought the autoinjector was easier to use., Conclusion: Use of an epinephrine autoinjector for treatment of contrast reactions was associated with a significantly greater degree of provider comfort, shorter time to administration, and fewer errors.

Objective: The purpose of this study is to investigate the effect of gadoxetate disodium administration on arterial phase respiratory waveforms., Subjects and Methods: From 2013 to 2015, 107 subjects undergoing liver MRI with either gadoxetate disodium (10 mL diluted 1:1 with saline; injection rate, 2 mL/s; n = 40) or gadobenate dimeglumine (0.2 mL/kg; maximum, 20 mL; injection rate, 2 mL/s; n = 67) were enrolled. Respiratory waveforms obtained during unenhanced and dynamic contrast-enhanced phases were filtered by a physicist, who was blinded to contrast agent and imaging phase, to eliminate electronic and cardiac noise using fast Fourier transformation. The average root-mean-square difference of two intrasubject control phases (unenhanced and late dynamic) was termed D1, and the root-mean-square deviation of the arterial phase referent to the control record mean was termed D2. D1, D2, and their difference were compared across agents with the Mann-Whitney U test. Bland-Altman plots were generated for D1 and D2 values., Results: D1 values were similar for both agents (mean [± SD], 232 ± 203 for gadoxetate vs 201 ± 230 for gadobenate; p = 0.48), indicating similar intercohort baseline breath-holding capability. D2 was greater and more variable for the gadoxetate cohort (438 ± 381) than for the gadobenate cohort (167 ± 167; p < 0.001), indicating larger and more unpredictable respiratory waveform deviations isolated to the arterial phase (subject-level rate, 48% [19/40] for gadoxetate vs 1% [1/67] for gadobenate; p < 0.001). Aberrant respiratory waveform peaks in the arterial phase were usually associated with transient tachypnea (mean maximum arterial phase respiratory rate for the gadoxetate cohort, 27 breaths/min; range, 11-40 breaths/min)., Conclusion: Fixed-dose gadoxetate disodium (10 mL; 1:1 dilution with 10 mL of saline; injection rate, 2 mL/s) transiently reduces breath-holding capacity during the arterial phase and is accompanied by brief transient tachypnea.

Objective: The objective of our study was to determine the effects of dehydration and oral rehydration on the incidence of acute adverse reactions to iodinated contrast media administered during abdominal and pelvic CT in outpatients., Subjects and Methods: For our prospective randomized study performed at a single institution, adult outpatients undergoing contrast-enhanced abdominal CT were randomly divided into a rehydration group (n = 2244 patients [1379 men and 865 women]; mean age, 65.2 years; age range, 18-90 years) and a control group (n = 3715 [2112 male patients and 1603 female patients]; mean age, 65.8 years; age range, 17-96 years), which included an age- and sex-matched subgroup (adjusted control group, n = 2244). The rehydration group received an oral rehydration solution (500 mL of liquid in which osmotic pressure is adjusted to enhance gastrointestinal absorption) before abdominal and pelvic CT. Patients were also divided into subclinically dehydrated (n = 997) and hydrated (n = 4962) groups according to their answers to a questionnaire that they completed before the CT examination. The patients were interviewed about contrast-induced adverse reactions before they left the CT room, and the reactions were categorized as allergiclike or physiologic. The incidence of reactions was compared between the rehydration and control groups and between the subclinical dehydration and hydrated groups. The rehydration and control groups were compared with an unpaired t test or a chi-square or Fisher test., Results: The overall incidence of an acute adverse reaction was 4.3% (254/5959); the acute adverse reactions included 136 allergiclike and 118 physiologic reactions. Fourteen allergiclike and nine physiologic reactions were moderate grade, and none was severe. There was no significant difference between the rehydration group and adjusted control group in the overall incidence of adverse reactions (99/2244 [4.4%] vs 100/2244 [4.5%], respectively; p = 0.9422) or between the subclinically dehydrated group and hydrated group in the incidence of allergiclike reactions (25/997 [2.5%] vs 111/4962 [2.2%], p = 0.6062) and physiologic reactions (22/997 [2.2%] vs 96/4962 [1.9%], p = 0.5793). Younger age was a risk factor for both allergiclike and physiologic reactions (p ≤ 0.0019)., Conclusion: Dehydration and oral rehydration did not affect the incidence of acute adverse reactions to iodinated contrast material for abdominal and pelvic CT in our randomized prospective trial.

Objective: The literature informs us that gadolinium can cause health issues. At least four major gadolinium disorders, including the two well-recognized nephrogenic systemic fibrosis and severe acute adverse event, have been identified., Conclusion: We propose naming the histopathologically proven presence of gadolinium in brain tissue "gadolinium storage condition," and we describe a new entity that represents symptomatic deposition of gadolinium in individuals with normal renal function, for which we propose the designation "gadolinium deposition disease."

Objective: The objective of our study was to assess the incidence of contrast-induced nephropathy (CIN), dialysis, and graft loss after direct intraarterial infusion of iodine-based contrast medium (CM) in renal allograft recipients., Materials and Methods: One hundred patients underwent renal graft catheter arteriography between 2006 and 2014. CIN was defined as an increase in serum creatinine value of 0.5 mg/dL or more above the creatinine value before arteriography. CIN could be assessed in 37 patients with creatinine levels obtained before arteriography and 24-72 hours after arteriography. Dialysis requirement and renal allograft loss at 30 days after the procedure were recorded in all 100 patients., Results: In the 37 patients who could be assessed for CIN, three patients (8%) met the criteria for CIN. In a subgroup analysis, there was an increased incidence of CIN in patients undergoing angiography alone (25%) compared with those in the angioplasty and stenting group (0%) (p = 0.028). At 30 days after the procedure, none (0/100) of the patients required dialysis or had graft failure., Conclusion: In a cohort of patients with a single renal allograft undergoing renal graft catheter arteriography using iodine-based CM, the overall incidence of CIN was low and no major adverse outcomes were noted at 30 days after the procedure. However, in a subgroup analysis, the patients who underwent arteriography alone-that is, without angioplasty or stenting-had a statistically significant higher rate of CIN.

Objective: This article reviews optimal treatment of allergic reactions to iodinated contrast material in pregnant patients. Initial evaluation and treatment of a pregnant patient is similar to that for a nonpregnant patient. However, additional steps, including assessment for uterine cramping, using left uterine displacement to improve venous return, and maintaining blood pressure to ensure placental perfusion, may be required., Conclusion: Adequate preparation and a team approach will provide optimal care for a pregnant patient who has an allergic reaction to a contrast agent.

Objective: The objective of our study was to determine the adverse reaction rate associated with the administration of blood pool contrast material in children and young adults., Materials and Methods: A review of the MRI and pharmacy databases identified all patients who received gadofosveset trisodium from October 1, 2011, to June 30, 2014. Patients were classified as having been anesthetized or not anesthetized for the MRI examinations. A review of the electronic medical records identified adverse reactions recorded within 24 hours of contrast administration. The adverse reactions were graded as mild, moderate, or severe. Risk ratios were calculated between the adverse reaction rate experienced by anesthetized patients and that experience by nonanesthetized patients., Results: During the study period, 626 patients (mean age, 11.7 years) received 711 doses of gadofosveset trisodium; 137 adverse reactions were recorded, which yields a 19.3% (137/711) adverse reaction rate. There were 115 adverse reactions experienced by 367 anesthetized patients (31.3%): 93.0% (107/115) were mild and 7.0% (8/115) were moderate. The remaining 22 adverse reactions were experienced by 344 (6.4%) nonanesthetized patients, and 90.9% (20/22) were mild. Three nonanesthetized patients had allergiclike reactions; of these allergiclike reactions, one was mild and two were severe for a severe allergiclike reaction rate of 0.28% (2/711). Severe allergiclike reactions were treated without any adverse outcomes. Anesthetized patients were 5.7 times more likely to experience an adverse event than nonanesthetized patients; most reactions in anesthetized patients were seen after the administration of anesthesia alone., Conclusion: Most reactions after gadofosveset trisodium administration in children and young adults are mild; however, severe allergiclike reactions occur, so policies must be in place to treat patients with adverse reactions when using this contrast agent. These data may be useful to centers considering administering gadofosveset trisodium to pediatric patients.

Objective: For unknown reasons, there is discordance among previous reports with regard to the association of contrast medium (CM) with nephropathy and the incidence of nephropathy after contrast-enhanced CT. This study aimed to determine the frequency of and possible factors related to CM-induced nephropathy in hospitalized patients, with an emphasis on detailing coprescriptions with nephrotoxic potential., Materials and Methods: Of 1378 inpatients who underwent CT, 208 (15.1%) met the inclusion criteria: receipt of IV iodinated CM and baseline serum creatinine level obtained within 45 days before and within 2 weeks after CT. Patient demographics, clinical characteristics, comorbidity, nephrotoxic comedications (nine classes of drugs), and type of CM administered were retrospectively reviewed. Relationships between CM-induced nephropathy (serum creatinine level increase ≥ 25% or ≥ 0.5 mg/dL after CT) and risk factors were assessed by stepwise multivariate logistic regression., Results: The cohort of 208 subjects had a high number of comorbidities (mean [± SD], 5.8 ± 3.5 diagnoses) and a high rate of receiving nephrotoxic comedications (45.2%). CM-induced nephropathy was detected in 27 (13.0%) patients. Concurrent use of four nephrotoxic agents (odds ratio [OR], 26.250; 95% CI, 3.673-233.993) was the most influential factor associated with CM-induced nephropathy; other predictors included preexisting renal disease (OR, 8.218; 95% CI, 1.622-42.357), baseline serum creatinine level less than 0.7 or greater than or equal to 1.3 mg/dL (OR, 3.463; 95% CI, 1.341-9.025), and hemoglobin level less than 9.3 g/dL (OR, 3.141; 95% CI, 1.087-8.946)., Conclusion: Among the known risk factors, such as preexisting renal disease, high serum creatinine level, and low hemoglobin level, a statistically significant association was identified between CM-induced nephropathy and concurrent receipt of four nephrotoxic medications. Relevant preventive measures are warranted for individuals at risk, especially hospitalized patients receiving multiple nephrotoxic medications who require contrast-enhanced CT.

Objective: The purpose of this study was to determine the incidence of nephrogenic systemic fibrosis (NSF) in patients with chronic kidney disease (CKD) and moderate-to-severe impairment of kidney function who had not previously been exposed to gadolinium-based contrast agents (GBCAs) or referred to undergo contrast-enhanced MRI with gadobenate dimeglumine or gadoteridol., Subjects and Methods: Two multicenter prospective cohort studies evaluated the incidence of unconfounded NSF in patients with stage 3 CKD (estimated glomerular filtration rate [eGFR] in cohort 1, 30-59 mL/min/1.73 m(2)) or stage 4 or 5 CKD (eGFR in cohort 2, < 30 mL/min/1.73 m(2)) after injection of gadobenate dimeglumine (study A) or gadoteridol (study B). A third study (study C) determined the incidence of NSF in patients with stage 4 or 5 CKD who had not received a GBCA in the 10 years before enrollment. Monitoring for signs and symptoms suggestive of NSF was performed via telephone at 1, 3, 6, and 18 months, with clinic visits occurring at 1 and 2 years., Results: For studies A and B, the populations evaluated for NSF comprised 363 and 171 patients, respectively, with 318 and 159 patients in cohort 1 of each study, respectively, and with 45 and 12 patients in cohort 2, respectively. No signs or symptoms of NSF were reported or detected during the 2 years of patient monitoring. Likewise, no cases of NSF were reported for any of the 405 subjects enrolled in study C., Conclusion: To our knowledge, and consistent with reports in the literature, no association of gadobenate dimeglumine or gadoteridol with unconfounded cases of NSF has yet been established. Study data confirm that both gadoteridol and gadobenate dimeglumine properly belong to the class of GBCAs considered to be associated with the lowest risk of NSF.

Objective: The purpose of this study was to identify opportunities for reducing epinephrine administration errors after a sentinel event entailing an overdose of i.v. epinephrine occurred in a radiology department., Materials and Methods: A root cause analysis was performed that included review and analysis of current system protocols, a medication audit, and access to treatment algorithms. A proctored three-question multiple-choice test was administered to radiology attending physicians, fellows, residents, and nurses to gauge baseline knowledge of epinephrine use. Chi-square analysis was performed., Results: Twelve of 13 radiology department central pharmacy automation system locations lacked epinephrine ampules. As a result, personnel had to access i.v. epinephrine stocked on hospital code carts designed for use during cardiac arrest. This led to errors related to appropriate dosing. Test participants included 46 attending physicians, 23 fellows, 28 residents, and 25 nurses (n = 122). Almost all (99%) correctly identified epinephrine as the medication to administer in this situation. Approximately one half (52%) correctly identified the dose of intramuscular epinephrine, but only 29% knew the dose and rate of administration of i.v. epinephrine (p < 0.001). Attending physicians were more likely to administer i.v. epinephrine correctly than were the other groups (p < 0.0001)., Conclusion: Stocking and routine auditing of medication availability are essential. The use of epinephrine intended for cardiac arrest stocked on code carts should be avoided during contrast reactions. It would be optimal if first-line responders to contrast reactions included attending physicians, but this may not always be the case at academic institutions.

Objective: The purpose of this study was to determine the rate of allergiclike breakthrough reactions among inpatients at high risk receiving premedication before undergoing CT with IV iodinated low-osmolality contrast material (LOCM)., Materials and Methods: Inpatients (n = 1051) completing a 13-hour corticosteroid and diphenhydramine premedication regimen before LOCM-enhanced CT from January 1, 2010, through December 31, 2013, were included in the study. Breakthrough reaction rates were compared with the ordinary allergiclike reaction rate in the general population (0.6% [545/84,928]) by use of chi-square tests. Multivariate logistic regression was performed. Number needed to treat (NNT) was calculated for patients premedicated for a previous contrast reaction., Results: Sixty percent (626/1051) of premedicated patients had had a previous reaction to iodinated contrast material, and 40% (425/1051) were premedicated for other reasons. The overall breakthrough reaction rates were 1.2% (13/1051) (p < 0.0001 vs the general population), 2.1% (13/626) for those with a previous iodinated contrast reaction (p < 0.0001), and 0% (0/425) for those premedicated for other reasons (p = 0.18). There were no severe breakthrough reactions. Younger age (p = 0.046; odds ratio, 1.03 per year; 95% CI, 1.001-1.07) and multiple indications for premedication (p < 0.0001; odds ratio, 2.7 per indication; 95% CI, 1.5-4.8) significantly increased the likelihood of a breakthrough reaction. The estimated NNTs were 69 (95% CI, 39-304) to prevent a reaction of any severity and 569 (95% CI, 389-1083) to prevent a severe reaction., Conclusion: Patients premedicated for a previous reaction to iodinated contrast material have a breakthrough reaction rate 3-4 times the ordinary reaction rate in the general population. Patients receiving premedication for other reasons have a breakthrough reaction rate near 0%. Many patients must receive premedication to prevent one reaction.

Objective: Successful management of a contrast reaction requires prompt recognition and treatment and effective team dynamics among radiologists, technologists, and nurses. A radiology department implemented a simulation program in which teams of nurses, technologists, and physicians managed simulated contrast reactions. The purpose of this study was to evaluate whether simulation improved the participants' abilities to manage a contrast reaction and work in a team during an emergency., Subjects and Methods: Physicians, nurses, and technologists worked in inter-professional teams to manage two high-fidelity simulated adverse contrast reactions. Participants completed surveys before and after the simulation that included knowledge-based questions about the appropriate management of contrast reactions. Surveys also included questions for assessing participants' perceptions of their ability to manage adverse contrast reactions, measured with a 6-point Likert scale. Before and after comparisons were made with the McNemar test with a Bonferroni correction requiring p ≤ 0.003 for significance. For the other analyses, p ≤ 0.05 was considered significant., Results: After completion of the simulation exercises, participants had significant improvement in knowledge (p < 0.001). After the simulation, participants reported significant improvement in their ability to manage an anaphylactoid reaction and their ability to work in a team (p < 0.00001). Participants requested repeat simulation exercises every 6-12 months., Conclusion: Simulation exercises improved the self-reported ability of radiology personnel to manage contrast reactions and work in a team during an emergency. Simulation should be incorporated into future educational initiatives to improve patient safety in radiology practices.

Objective: Anaphylactoidlike reactions occur during the nonvascular administration of iodinated contrast media. Many of these reactions have been severe. These reactions have occurred with many procedures, including gastrointestinal imaging, cystography, sialography, and hysterosalpingography., Conclusion: This article reviews reports of these reactions. It also reviews what the literature recommends concerning how to deal with individuals undergoing these procedures who are at a higher risk for anaphylactoidlike reactions.

Objective: The purpose of this study was to determine the incidence of adverse events associated with gadobenate dimeglumine over 7.5 years in a major hospital system consisting of both academic and community hospitals., Subjects and Methods: As part of a regular and continuous prospective quality assurance project, MRI technologists contemporaneously recorded all gadolinium-based contrast administrations and any associated adverse reactions, including type of reaction and treatment rendered, between August 1, 2005, and March 14, 2013. Weekly data review was performed by the director of MRI services, who evaluated data both by individual site and by comparison among the participating hospitals and sites within the hospital system. Comparison between reaction rates at different sites was performed with a chi-square test., Results: Over 7.5 years, 132,252 doses of gadobenate dimeglumine were administered, and 236 reactions were recorded (0.18% of contrast-enhanced examinations). Of these, 133 (56.4% of all adverse reactions) required treatment and 12 (5.1%) qualified as serious. Reaction rates were significantly different between academic (0.23%) and community (0.07%) hospitals (p<0.001). Reaction rates were higher in the initial years of the study, tapering to a lower baseline rate, which was maintained over more than 5 years. The findings were consistent with the Weber and Lalli effects reported in the literature on other pharmaceutical agents., Conclusion: Rates of adverse reactions to gadobenate dimeglumine recorded over 7.5 years were comparable to those reported for other gadolinium-based contrast agents examined over smaller time ranges and populations. The findings reinforce the relatively robust safety profile of this agent.