Shadi Aminololama-Shakeri MD, Presenter: Nothing to Disclose

Peymon Gazi MS, Abstract Co-Author: Nothing to Disclose

Karen K. Lindfors MD, Abstract Co-Author: Research Grant, Hologic, Inc

John M. Boone PhD, Abstract Co-Author: Research Grant, Siemens AG Research Grant, Hologic, Inc Consultant, Varian Medical Systems, Inc

Patients undergoing contrast enhanced dedicated breast computed tomography (CEbCT) have sequential imaging of both breasts following an intravenous injection of iodine based contrast material. This sequential scanning protocol with one breast imaged at a slightly more delayed time post contrast than the contralateral side has raised questions regarding lesion depiction. The goal of this study was to measure lesion depiction as a function of time after contrast injection.

90 consecutive patients with BIRADS 4 or 5 lesions were prospectively enrolled. All patients had CEbCT after IV injection of 100 ml of iodixanol 320 at a rate of 3 ml/s, followed by core biopsy. Two experienced radiologists independently reviewed each study and assigned a conspicuity score (CS) of 0-10 for each biopsied lesion (0=not seen, 10=excellent conspicuity). A subset of patients (50) also had qualitative assessment of the background breast parenchymal enhancement, subjectively categorized into minimal, mild, moderate or marked by the readers and correlated to the early and late contrast delay times. Time from contrast injection to CEbCT imaging ranged from 70 to 492 sec. Contrast delay times of 70-95s were defined as early (n=73) and times ranging from 165 to 492s were defined as late (n=17). CS and delay times are shown as mean +/-SD. Significant differences among conspicuity of lesions in early versus late delay time groups (p<0.05) were tested with two sided paired t-test or Wilcoxon signed-rank test. (GraphPad Prism v5).

Breast lesions were equally conspicuous in the early and late contrast delay time groups with CS of 7.3 +/- 3.2, n=39 and 7.1 +/- 3.7, n=39 respectively. Background parenchymal enhancement categories were equally distributed with early and delayed contrast times. 83% (34/41) of breasts imaged at the early contrast time showed minimal/mild and 17% (7/41) showed moderate/ marked background parenchymal enhancement. 78% (7/9) of the breasts imaged at the late contrast delay time showed minimal/mild and 22% (2/7) showed moderate/ marked background parenchymal enhancement.

There is no correlation between conspicuity scores of BIRADS 4 and 5 breast lesions and contrast timing on CEbCT. Contrast time does not correlate with background parenchymal enhancement and does not affect conspicuity of breast lesions on CEbCT.

CEbct lesion depiction is not contrast time dependent.

Aminololama-Shakeri, S, Gazi, P, Lindfors, K, Boone, J, Is Lesion Depiction on Contrast Enhanced Dedicated Breast Computed Tomography Affected by Contrast Timing?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13028366.html