Dose-toxicity relationship of gadoxetate disodium and transient severe respiratory motion artifact.

OBJECTIVE: The purpose of this article is to determine whether there is a dose-toxicity relationship between gadoxetate disodium and transient severe respiratory motion artifact. MATERIALS AND METHODS: Gadoxetate disodium-enhanced MRI studies (559 studies of 559 patients) using a fixed 20-mL (2 mL/s; n = 112) or 10-mL (1-2 mL/s; n = 447) volume at two health systems were included (dose range, 0.05-0.42 mL/kg; mean, 0.15 mL/kg; above-label dosing, 479 [86%]). Each dynamic phase was assigned a respiratory motion score from 1 (none) to 5 (nondiagnostic). Examinations with an unenhanced score of 1-2, arterial score of 4-5, and venous or late-dynamic scores of 1-3 were labeled as transient severe respiratory motion artifact. Stepwise multivariate logistic regression was performed. RESULTS: The overall incidence of transient severe respiratory motion artifact was 12% (67/559; site 1, 15% [35/232]; site 2, 9.8% [32/327]). The administered volume of contrast material had a statistically significant effect (20 mL, 20% [22/112] vs 10 mL, 10%, [45/447]; multivariate p = 0.01; odds ratio, 2.1 [20 vs 10 mL]; 95% CI, 1.2-3.7). There was no dose-toxicity relationship for dose-by-weight (p = 0.61 [multivariate]) or above-label dosing (p = 0.88 [univariate]; 13% [10/80] rate for at- or below-label dosing vs 12% [57/479] rate for above-label dosing). Chronic obstructive pulmonary disease was the only non-dose-related predictor in the multivariate model (p < 0.0001; OR, 5.1 [95% CI, 2.5-11.5]; 39% [12/31] vs 10% [55/528]). CONCLUSION: Gadoxetate disodium-associated transient severe respiratory motion artifact is significantly more common after 20-mL administration (2 mL/s) and occurs significantly more often in patients with chronic obstructive pulmonary disease. The volume-related effect suggests a nonallergiclike mechanism.

"Concordance" Revisited: A Multispecialty Appraisal of "Concordant" Preliminary Abdominopelvic CT Reports.

PURPOSE: To determine whether resident abdominopelvic CT reports considered prospectively concordant with the final interpretation are also considered concordant by other blinded specialists and abdominal radiologists. METHODS: In this institutional review board-approved retrospective cohort study, 119 randomly selected urgent abdominopelvic CT examinations with a resident preliminary report deemed prospectively "concordant" by the signing faculty were identified. Nine blinded specialists from Emergency Medicine, Internal Medicine, and Abdominal Radiology reviewed the preliminary and final reports and scored the preliminary report with respect to urgent findings as follows: 1.) concordant; 2.) discordant with minor differences; 3.) discordant with major differences that do not alter patient management; or 4.) discordant with major differences that do alter patient management. Predicted management resulting from scores of 4 was recorded. Consensus was defined as majority agreement within a specialty. Consensus major discrepancy rates (ie, scores 3 or 4) were compared to the original major discrepancy rate of 0% (0/119) using the McNemar test. RESULTS: Consensus scores of 4 were assigned in 18% (21/119, P < .001, Emergency Medicine), 5% (6/119, P = .03, Internal Medicine), and 13% (16/119, P < .001, Abdominal Radiology) of examinations. Consensus scores of 3 or 4 were assigned in 31% (37/119, P < .001, Emergency Medicine), 14% (17/119, P < .001, Internal Medicine), and 18% (22/119, P < .001, Abdominal Radiology). Predicted management alterations included hospital status (0-4%), medical therapy (1%-4%), imaging (1%-10%), subspecialty consultation (3%-13%), nonsurgical procedure (3%), operation (1%-3%), and other (0-3%). CONCLUSIONS: The historical low major discrepancy rate for urgent findings between resident and faculty radiologists is likely underreported.