Immediate Hypersensitivity to Contrast Agents: The French 5-year CIRTACI Study.

BACKGROUND: Iodinated and gadolinium-based contrast media (ICM; GBCM) induce immediate hypersensitivity (IH) reactions. Differentiating allergic from non-allergic IH is crucial; allergy contraindicates the culprit agent for life. We studied frequency of allergic IH among ICM or GBCM reactors. METHODS: Patients were recruited in 31 hospitals between 2005 and 2009. Clinical symptoms, plasma histamine and tryptase concentrations and skin tests were recorded. Allergic IH was diagnosed by intradermal tests (IDT) with the culprit CM diluted 1:10, "potentially allergic" IH by positive IDT with pure CM, and non-allergic IH by negative IDT. FINDINGS: Among 245 skin-tested patients (ICM = 209; GBCM = 36), allergic IH to ICM was identified in 41 (19.6%) and to GBCM in 10 (27.8%). Skin cross-reactivity was observed in 11 patients with ICM (26.8%) and 5 with GBCM (50%). Allergy frequency increased with clinical severity and histamine and tryptase concentrations (p < 0.0001). Cardiovascular signs were strongly associated with allergy. Non-allergic IH was observed in 152 patients (62%) (ICM:134; GBCM:18). Severity grade was lower (p < 0.0001) and reaction delay longer (11.6 vs 5.6 min; p < 0.001). Potentially allergic IH was diagnosed in 42 patients (17.1%) (ICM:34; GBCM:8). The delay, severity grade, and mediator release were intermediate between the two other groups. INTERPRETATION: Allergic IH accounted for < 10% of cutaneous reactions, and > 50% of life-threatening ones. GBCM and ICM triggered comparable IH reactions in frequency and severity. Cross-reactivity was frequent, especially for GBCM. We propose considering skin testing with pure contrast agent, as it is more sensitive than the usual 1:10 dilution criteria.

Mangafodipir-enhanced magnetic resonance cholangiography for the diagnosis of bile duct leaks.

BACKGROUND: The purpose of this prospective study was to assess the value of contrast-enhanced magnetic resonance cholangiography with mangafodipir trisodium perfusion for detection and localization of trauma-induced and postoperative bile duct leaks. METHODS: Eleven patients with suspected bile duct leaks after trauma (n=5) or surgery (n=6) were included. Patients with suspected leaks after cholecystectomy were excluded. All patients underwent contrast-enhanced magnetic resonance cholangiography with two-dimensional axial and three-dimensional coronal gradient-echo images acquired 1 to 3 hours after intravenous administration of mangafodipir trisodium perfusion. Contrast-enhanced magnetic resonance cholangiography findings were correlated with direct cholangiography obtained in all patients, including endoscopic retrograde (n=7) and percutaneous transhepatic cholangiography (n=4). RESULTS: Biliary tract enhancement was identified in all patients on contrast-enhanced magnetic resonance cholangiography. Peritoneal cavity fluid and bile collections that contained extravasated mangafodipir trisodium (increased signal intensity on gradient-echo sequences) were demonstrated in 6 patients. Direct cholangiography confirmed the presence of bile duct leaks in these 6 patients and the absence of bile duct leaks in 5 patients. There was no false-negative or false-positive contrast-enhanced magnetic resonance cholangiography. CONCLUSIONS: Mangafodipir-enhanced magnetic resonance cholangiography is a noninvasive technique that can provide functional biliary information with excellent depiction of bile duct leaks.

Contribution of magnetic resonance cholangiopancreatography to the management of patients with suspected common bile duct stones.

OBJECTIVES: To evaluate the value of magnetic resonance cholangiography (MRC) as a systematic first-line investigation in the management of patients with suspected common bile duct stones. METHODS: Ninety-nine consecutive patients with clinical suspicion of choledocolithiasis were prospectively explored by MRC. All MRCs were interpreted by two radiologists with knowledge of the patient's clinical condition and laboratory results. In case of discrepancy, a third opinion was obtained to reach consensus. The definitive diagnosis was established on the basis of endoscopic exploration of the common bile duct (n=40), clinical and biological follow-up at 6 Months (n=55) or other investigations (n=4). The clinician's level of confidence, management options implemented, and impact of management decisions were used to assess the contribution of MRC. The diagnostic accuracy of MRC for common bile duct stones was also determined. RESULTS: At the observed level of confidence (85.9%), MRC identified a differential diagnosis in 7.1% of patients avoiding unnecessary endoscopic exploration in 59.6%. Systematic first-line MRC enabled appropriate management in 83.8% of patients. The sensitivity, specificity, and positive and negative predictive values of MRC for the diagnosis of common bile duct stones were 95.7%, 98.7%, 95.7% and 98.7%, respectively, with excellent inter-observer agreement (kappa=0.915). CONCLUSION: Magnetic resonance cholangiography can be used to efficiently screen patients who may need further invasive exploration of the common bile duct. It specifically identifies patients requiring therapeutic ERCP.