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SU-E-I-65: Pitfalls in the Production of Enhancement Kinetic Curves in 3T Dynamic Magnetic Resonance Mammography and Means of Avoidance.

PURPOSE
The purpose of the present study is to investigate suggested means for the reduction or even elimination of errors that appear in enhancement kinetic curves in order to avoid pitfalls and increase the sensitivity and specificity of the method.


METHODS
This retrospective study included 115 women who underwent breast MRI in a magnetic resonance unit 3-Tesla. In the MRI acquisition the following sequences were used: a) axial T2-TSE, b) axial STIR and c) Vibrant (six phases) unenhanced and contrast-enhanced axial T1-weighted fat saturation. In the semi-automated technique there was no consistency in the location of the selected region of interest - ROI in all the phases of the dynamic acquisition during the assessment of the kinetic curves. The measurements were repeated by positioning the ROIs manually from stable reference points in all the phases and the enhancement kinetic curves were subsequently plotted based on the signal intensity.


RESULTS
115 patients were examined and 376 abnormalities were investigated. In 81 cases, a change of the enhancement kinetic curve type was found between the two methods. In large and dense breasts there was not any change in the type of the kinetic curves calculated between the two methods, whereas in the large but non-dense breasts, 13 lesions were found to be of different type. In the case of the small and dense breasts only 4 lesions changed type, whereas in the case of the small and non-dense breasts, 64 lesions changed type out of which 50 were observed in left breasts and 14 in right breasts.


CONCLUSION
The derivation of enhancement kinetic curves should be performed by controlling and verifying that the ROIs lay at the same location of the lesion in all the phases of the dynamic study. In these cases, the use of stable reference points should be employed.