Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury.

Iodinated contrast media (ICM) is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after ICM administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. This revised guidance document was developed by a multidisciplinary CAR Working Group of radiologists and nephrologists, and summarizes changes in practice related to contrast administration, screening, and risk stratification since the last guideline. It reviews the scientific evidence for contrast associated AKI and provides consensus-based recommendations for its prevention and management in the Canadian healthcare context. This article is a joint publication in the Canadian Association of Radiologists Journal and Canadian Journal of Kidney Health and Disease, intended to inform both communities of practice.

Horseshoe adrenal gland: a rare congenital anomaly.

A solitary adrenal gland spanning the midline has been alternatively described as "Horseshoe" or "Butterfly" and is a rare congenital abnormality almost exclusively associated with neonates. There have been 65 reported cases in fetuses and infants, based on ultrasound and autopsy findings. Horseshoe adrenal gland is associated with several congenital anomalies, such as asplenia (52 %), neural tube defects (37 %), renal abnormalities (29 %), and diaphragmatic defects (1 %). Recently, Feldman and colleagues [2] reported the first case of an adult male with horseshoe adrenal gland and posterior midline diaphragmatic anomaly found incidentally with CT imaging. We present a second case of asymptomatic adult horseshoe adrenal gland with posterior midline diaphragmatic hernia in a 51-year-old woman discovered on CT imaging. In our patient these abnormalities were also associated with a 9th thoracic butterfly vertebrae and a unilateral region of underdevelopment of the paraspinal musculature at the level of the diaphragmatic defect. To our knowledge, this is the first time this abnormality has been documented with MRI.

Canadian Association of Radiologists Guidance on Contrast-Associated Acute Kidney Injury.

Purpose: Iodinated contrast media is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after iodinated contrast administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow-up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. Information sources: Published literature, including clinical trials, retrospective cohort series, review articles, and case reports, along with expert opinions from radiologists and nephrologists across Canada. Methods: The leadership of the CAR formed a working group of radiologists and nephrologists with expertise in contrast administration and patient management related to contrast-associated AKI. We conducted a comprehensive review of the published literature to evaluate the evidence about contrast as a cause of AKI, and to inform evidence-based recommendations. Based on the available literature, the working group developed consensus recommendations. Key Findings: The working group developed 21 recommendations, on screening, choice of iodinated contrast media, prophylaxis, medication considerations, and post contrast administration management. The key changes from the 2012 guidelines were (1) Simplification of screening to a simple questionnaire, and not delaying emergent examinations due to a need for creatinine measurements (2) Prophylaxis considerations only for patients with estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 (3) Not recommending the routine discontinuation of any drugs to decrease risk of AKI, except metformin when eGFR is less than 30 mL/min/1.73 m2 and (4) Not requiring routine follow up serum creatinine measurements post iodinated contrast administration. Limitations: We did not conduct a formal systematic review or meta-analysis. We did not evaluate our specific suggestions in the clinical environment. Implications: Given the importance of iodinated contrast media use in diagnosis and management, and the low risk of AKI after contrast use, these guidelines aim to streamline the processes around iodinated contrast use in most clinical settings. As newer evidence arises that may change or add to the recommendations provided, the working group will revise these guidelines.

Justification: Les agents de contraste iodés (ACI) sont parmi les produits pharmaceutiques les plus fréquemment administrés. Au Canada, plus de 5,4 millions d'examens de tomodensitométrie (TDM) ont été réalisés en 2019, dont 50 % ont été faits avec un ACI. L'insuffisance rénale aiguë (IRA) survenant après l'administration d'un ACI était historiquement considérée comme une complication iatrogénique fréquente qui était prise en charge par le dépistage des patients, des stratégies prophylactiques et une évaluation de suivi de la fonction rénale. L'Association canadienne des radiologistes (CAR) a publié des lignes directrices pour la prévention de la néphropathie induite par les agents de contraste en 2007 et une mise à jour en 2012. De nouveaux développements sur le terrain ont toutefois mené à la disponibilité d'agents de contraste plus sécuritaires et à des changements dans la pratique clinique, ce qui a entraîné une révision complète des recommandations antérieures. Sources: La littérature publiée, y compris les essais cliniques, les séries de cohortes rétrospectives, les articles-synthèse et les rapports de cas, de même que les opinions d'experts de radiologistes et de néphrologues de partout au Canada. Méthodologie: La direction de la CAR a formé un groupe de travail composé de radiologues et de néphrologues ayant une expertise dans l'administration d'ACI et la gestion de patients atteints d'IRA survenant après l'administration d'un ACI. Le groupe a procédé à une revue complète de la littérature publiée afin d'évaluer les données probantes sur les ACI comme cause de l'IRA et de formuler des recommandations en fonction de celles-ci. Le groupe de travail a élaboré des recommandations consensuelles en se fondant sur la documentation disponible. Principaux résultats: Le groupe de travail a élaboré 21 recommandations sur le dépistage, le choix des agents de contraste iodés, la prophylaxie, les considérations relatives aux médicaments et la gestion post-administration de l'ACI. Les principaux changements par rapport aux lignes directrices de 2012 étaient : (1) de simplifier le dépistage à un simple questionnaire et de ne pas retarder les examens émergents en raison du besoin de mesurer la créatinine; (2) d'avoir des considérations prophylactiques uniquement pour les patients dont le débit de filtration glomérulaire estimé (DFGe) est inférieur à 30 mL/min/1,73 m2; (3) de ne pas recommander l'arrêt des médicaments visant à réduire le risque d'IRA, comme c'est normalement le cas, sauf la metformine lorsque le DFGe est inférieur à 30 mL/min/1,73 m2 et; (4) ne pas demander de mesures de suivi de routine de la créatinine sérique après administration d'un agent de contraste iodé. Limites: Le groupe n'a pas procédé à une revue formelle et systématique de la littérature sur le sujet ni à une méta-analyse. Les suggestions n'ont pas été évaluées dans un environnement clinique. Conclusion: Compte tenu de l'importance des agents de contraste iodés dans le diagnostic et la prise en charge des patients, et du faible risque d'IRA encouru après leur administration, ces recommandations ne visent qu'à simplifier les processus relatifs à l'utilisation des ACI dans la plupart des milieux cliniques. Le groupe de travail révisera ces lignes directrices au fur et à mesure que des éléments de preuve plus récents seront ajoutés aux recommandations fournies.

Calcified cavitating mesenteric lymph node syndrome: case presentation and literature review.

Cavitating mesenteric lymph node syndrome (CMLNS) is a rare complication of celiac disease. Globally, only 36 cases of CMLNS have been reported to date. The present article reports an incidence of its unique pathology and possible complications of celiac disease, followed by a review of the syndrome. A case involving a 51-year-old man with celiac disease who was referred to hospital because of a nontender abdominal mass is described. Plain film x-ray of the abdomen revealed fine curvilinear calcifications in the left lower quadrant. A complex, cystic-appearing, lobulated mass with somewhat echogenic walls most consistent with calcifications was revealed on subsequent ultrasound (US) imaging. Colour Doppler imaging showed no evidence of vascularity within the lesion. Computed tomography (CT) imaging showed a thin rim of calcification in the walls of multiple cystic components. Enhanced magnetic resonance (MR) imaging revealed a mixed solid and cystic multiloculated mass, with fat-fluid layers originating from the root of the small bowel mesentery. A CT-guided biopsy was performed. The fine-needle aspirate revealed calcified matter with no associated cellular material. No malignant cells were seen; CMLNS was established as the diagnosis. To the authors' knowledge, there are no previous reports in the literature describing the finding of rim calcification on US or MR imaging in the setting of CMLNS. CMLNS is an important diagnosis to consider, particularly in patients with a history of celiac disease. The finding of rim calcification on US in the setting of cavitating mesenteric adenopathy should prompt further diagnostic imaging studies such as CT or MR imaging. These may lead to additional pathology studies such as a CT-guided biopsy to further characterize the lesion at the cellular level, to investigate potential malignancy and to further guide follow-up and patient management.

Prevalence of risk factors for contrast-induced nephrotoxicity in outpatients undergoing intravenous contrast-enhanced computed tomography studies.

OBJECTIVE: To document the prevalence and pattern of risk factors for contrast-induced nephrotoxicity (CIN) in an outpatient population referred for contrast-enhanced computed tomography (CT) (CECT) studies. METHODS: Over a 4-month period, 3261 patients presenting for CT studies were asked to consent to a survey of CIN risk factors. Among these patients, 957 were outpatients who received contrast material before the CT study. Demographic information and available serum creatinine (SCr) data for these patients were extracted from medical records and then analysed. A telephone questionnaire to document risk factors was administered to 200 of these patients, who were outpatients not referred from the emergency department or on dialysis. RESULTS: Among the 200 surveyed patients, 69% reported risk factors for CIN or for kidney function impairment (low estimated glomerular filtration rate [eGFR]) at baseline. Among these patients, 43% reported multiple (2 or more) risk factors. Patients older than the mean age of 53 years had a higher incidence of having multiple risk factors when compared with those younger than this age. Patients with kidney function impairment at baseline had a higher incidence of having multiple risk factors when compared with those with normal kidney function. Among the patients with no SCr investigation in the 3 months preceding a CECT, 64% had multiple risk factors. In the study population of 957 outpatients undergoing CECT, 52% had SCr measurements within 3 months before the study. An eGFR of less than 60 mL/min/1.73 m(2) was found in 17% of the study population, and, in 0.6%, the eGFR was less than 30 mL/min/1.73 m(2). CONCLUSION: In an ambulatory outpatient population, many patients presenting for outpatient CECT studies will have risk factors for CIN or for kidney function impairment (low eGFR) at baseline. Kidney function assessment, therefore, is indicated in this patient population before CECT.