A Quantification Method for Breast Tissue Thickness and Iodine Concentration Using Photon-Counting Detector

Abstract

The purpose of contrast-enhanced digital mammography (CEDM) is to facilitate detection and characterization of the lesions in the breast using intravenous injection of an iodinated contrast agent. CEDM produces iodine images with gray levels proportional to iodine concentration at each pixel, which can be considered as quantification of iodine. While dual-energy CEDM requires an accurate knowledge of the thickness of compressed breast for the quantification, it is known that the accuracy of the built-in thickness measurement is not satisfactory. Triple-energy CEDM, which can provide a third image, can alleviate the limitation of dual-energy CEDM. If triple exposure technique is applied, it can lead to increased risk of motion artifact. An energy-resolving photoncounting detector (PCD) that can acquire multispectral X-ray images can reduce the risk of motion artifact. In this research, an easily implementable method for iodine quantification in breast imaging was suggested, and it was applied to the images of breast phantom with various iodine concentrations. The iodine concentrations in breast phantom simulate lesions filled with different iodine concentrations in the breast. The result shows that the proposed method can quantify the iodine concentrations in breast phantom accurately.

Susceptibility of iodine concentration map of dual-energy contrast-enhanced digital mammography for quantitative and tumor enhancement assessment

“…However, the relative error was higher for concentrations <1 mg/cm 2 . This higher error may be related to the limitation of the minimum detectable iodine concentration (30) as well as to the higher handling uncertainties for lower iodine concentrations. Because an iodine concentration of 1 mg/cm 2 has been considered to be the lower part of the clinically relevant iodine concentration range (8,15), the higher relative error obtained in this study for iodine concentrations < 1 mg/cm 2 was considered to be acceptable.…”

“…Second, to simplify the simulation, the contrast medium was filled in flatbottomed cylindrical wells. However, quantitative estimations were considered different for irregular or spiculate lesion shapes that are represented in real clinical situations (30,32). The primary objective of this study was not to estimate the absolute iodine concentration uptake but to propose a detailed quantitative calibration method for converting DE images into a colorcoded iodine map for obtaining additional interpretation information for tumor enhancement assessments.…”

“…Our study has some limitations. First, because the current DE-CEDM technique is based on only two image acquisitions, the overlapping normal breast tissue can obscure the iodine detection without a priori knowledge of the breast tissue thickness for each pixel (30). Our iodine concentration calibrations were performed using 3-mm-deep iodine-filled cylindrical wells for all phantom thicknesses investigated without considering variations in lesion thickness, which could have affected the accuracy of iodine concentration estimations when quantitative calibrations were applied to clinical images.…”

Patient‐based 4D digital breast phantom for perfusion contrast‐enhanced breast CT imaging

“…The amplitude of the curve depends on the contrast medium concentration injected in the breast through its major vasculature, which is another user‐selectable parameter. In this work, we set it to 10 mg(I)/mL . The AIF, beside modeling the iodinated solution in‐ and out‐flow within blood vessels, also influences the concentration of iodine in the other breast tissues, as described in the following subsections.…”

“…In this work, we set it to 10 mg(I)/mL. 30 The AIF, beside modeling the iodinated solution in-and out-flow within blood vessels, also influences the concentration of iodine in the other breast tissues, as described in the following subsections.…”