Interactive visualization of fused fMRI and DTI for planning brain tumor resections

The surgical removal of brain tumors can lead to functional impairment. Therefore it is crucial to minimize the damage to important functional areas during surgery. These areas can be mapped before surgery by using functional MRI. However, functional impairment is not only caused by damage to these areas themselves. It is also caused by damage to the fiber bundles that connect these areas with the rest of the brain. Diffusion Tensor Images (DTI) can add information about these connecting fiber bundles. In this paper we present interactive visualization techniques that combine DTI, fMRI and structural MRI to assist the planning of brain tumor surgery. Using a fusion of these datasets, we can extract the fiber bundles that pass through an offset region around the tumor, as can be seen in Figure 1. These bundles can then be explored by filtering on distance to the tumor, or by selecting a specific functional area. This approach enables the surgeon to combine all this information in a highly interactive environment in order to explore the pre-operative situation.Data Visualization GroupElectrical Engineering, Mathematics and Computer Scienc

Added value of multiphase CTA imaging for thrombus perviousness assessment

Purpose: Thrombus perviousness has been associated with favorable functional outcome in acute ischemic stroke (AIS) patients. Measuring thrombus perviousness on CTA may be suboptimal due to potential delay in contrast agent arrival in occluded arteries at the moment of imaging. Dynamic sequences acquired over time can potentially overcome this issue. We investigate if dynamic CTA has added value in assessing thrombus perviousness. Methods: Prospectively collected image data of AIS patients with proven occlusion of the anterior or posterior circulation with thin-slice multi-phase CTA (MCTA) and non-contrast CT were co-registered (n = 221). Thrombus attenuation increase (TAI; a perviousness measure) was measured for the arterial, venous, and delayed phase of the MCTA and time-invariant CTAs (TiCTA). Associations with favorable clinical outcome (90-day mRS ≤ 2) were assessed using univariate and multivariable regressions and calculating areas under receiver operating curves (AUC). Results: TAI determined from the arterial phase CTA was superior in the association with favorable outcome with OR = 1.21 per 10 HU increase (95%CI 1.04–1.41, AUC 0.62, p = 0.014) compared to any other phase (venous 1.14(95%CI 1.01–1.30, AUC 0.58, p = 0.033), delayed 1.046(95%CI 0.919–1.19, AUC 0.53, p = 0.50)), and TiCTA (1.15(95%CI 1.02–1.30, AUC 0.60, p = 0.022). In the multivariable model, only TAI on arterial phase was significantly associated with favorable outcome (aOR 1.59, 95%CI 1.04–2.43, p = 0.032). Conclusion: Association between TAI with functional outcome was optimal on arterial-phase CTA such that dynamic CTA imaging has no additional benefits in current thrombus perviousness assessment, thereby suggesting that the delay of contrast arrival at the clot is a key variable for patient functional outcome.ImPhys/Quantitative Imagin