Dual-Energy CT for Detection of Endoleaks After Endovascular Abdominal Aneurysm Repair: Usefulness of Colored Iodine Overlay

Abstract

Dual-energy CT with colored iodine overlay is a useful diagnostic tool in endoleak detection. The use of a dual-energy single-phase study protocol will lower radiation exposure to patients.

Nonlinear Image Blending for Dual-Energy MDCT of the Abdomen: Can Image Quality Be Preserved If the Contrast Medium Dose Is Reduced?

“…Another limitation to our research was that we compared nonlinear blended images at reduced contrast medium load with simulated 120-kVp linear blended images at a full dose. Although the latter image dataset has been shown to closely reflect conventional single-energy 120-kVp images [13][14][15][16][17][18], it could be argued that variances to our results could emerge if nonlinear blended images had been compared with conventional single-energy 120-kVp images. However, given that some authors have reported advantages of simulated 120-kVp linear blended images over conventional 120-kVp images [14], it is conceivable that the gain in terms of iodine CNR could have been even greater if we had compared nonlinear blended images with conventional single-energy 120-kVp images.…”

“…In all patients, linear blended images were reconstructed with a default linear blending ratio of 0.3, meaning that the low-kVp information is multiplied by a factor of 0.3 and is added to the high-kVp information, which is multiplied by a factor of 0.7. The result is a linear blended image dataset having an image quality that theoretically corresponds to a conventional single-energy 120-kVp acquisition [13][14][15][16][17][18]. All examinations were stored on a secondary workstation equipped with dedicated dual-energy software (Syngo Dual Energy, version MMWP 2010A, Siemens Healthcare).…”

“…The dichotomy between the characteristics of low-tube voltage (kVp) data (high contrast with high noise) and high-kVp data (low contrast with low noise) derived from a dual-energy acquisition is solved by linearly blending them in one image dataset [13,14]. A blending ratio of 0.3 between the high-and low-energy information (i.e., 70% weight for 140-kVp data and 30% weight for 80-kVp data) has been shown to closely reproduce conventional single-energy 120-kVp images [13][14][15][16][17][18]. More recently, a nonlinear image blending technique was developed in an attempt to maximize the contribution from the high-contrast low-energy dataset [19].…”

Dual-Energy Computed Tomography

“…Iodine overlay images increase confidence in detecting endoleaks after aortic stent graft placement. 66 VNC images are valuable in the emergency setting to increase the conspicuity between enhancing soft tissue and dense noniodine-containing materials, such as hematomas in the bowel wall, peritoneal cavity, or abdominal wall (Figs. 12 and 13).…”

MDCT of endoleaks following endovascular repair of abdominal aortic aneurysms

“…Additionally, the use of dual energy CT has allowed reconstruction of virtual non-contrast images to substitute for actual image acquisition of the traditional non-contrast phase [23,24]. It has also been demonstrated that reconstruction of virtual non-contrast images and additional post-processing techniques from a single phase, dual-energy protocol significantly lowers radiation dose while maintaining extremely high diagnostic accuracy [25].…”