OBJECTIVE To assess associations between patient characteristics and apparent diffusion coefficient (ADC) values of normal breast fibroglandular tissue on diffusion-weighted imaging (DWI) at 3 tesla. MATERIALS and METHODS The retrospective study included 103 women with negative bilateral findings on 3T breast MR examinations (BI-RADS 1). DWI was acquired during clinical breast MRI scans using b = 0, 800 s/mm2. Mean ADC of normal breast fibroglandular tissue was calculated for each breast using a semi-automated software tool in which parenchyma pixels were selected by interactive thresholding of the b=0 s/mm2 image to exclude fat. Intrasubject right and left breast ADC values were compared and averaged together to evaluate the association of mean breast ADC with age, mammographic breast density and background parenchymal enhancement (BPE). RESULTS Overall mean breast ADC was 1.62±0.30 ×10−3mm2/s. Intrasubject right and left breast ADC measurements were highly correlated (R2=0.89, p<0.0001). Increased breast density was strongly associated with increased ADC (p=<0.0001). Age and BPE were not associated with ADC. CONCLUSION Normal breast parenchymal ADC values increase with mammographic density, but are independent of age and BPE. Since breast malignancies have been shown to have low ADC values, DWI may be particularly valuable in women with dense breasts due to greater lesion to normal tissue contrast.

The objectives of this article are to review the diagnosis and management of acute nonrenal reactions to iodinated contrast media. We will begin by discussing the types of contrast media and their correlative rates of reaction. The mechanism of contrast reactions, predisposing risk factors, and preventative measures will then be discussed. The remainder of the article will review the assessment of potential reactions, initial management, and treatment algorithms for specific reactions.

When compared with didactic lecture, high-fidelity simulation-based training of contrast reaction management shows equal results on written test scores but improved performance during a high-fidelity severe contrast reaction simulation scenario.