Blood flow in its context: combining 3D B-mode and color Doppler ultrasonic data.

Visualization of volumetric multicomponent data sets is a high-dimensional problem, especially for color data. Medical 3D ultrasound (US) technology has rapidly advanced during the last few decades and scanners can now generate joint 3D scans of tissues (B-mode) and blood flow (power or color Doppler) in real time. Renderings of such data sets have to comprehensively convey both the relevant structures of the tissues that form the context for blood flow, as well as the distribution of blood flow itself. The narrow field of view in US data, which is often used to make real-time imaging possible, complicates volume exploration since only parts of organs are usually visible; that is, clearly defined anatomical landmarks are scarce. In addition, the noisy nature and low signal-to-contrast ratio of US data make effective visualization a challenge, whereby there are currently no convincing solutions for combined US B-mode and color Doppler data rendering. Therefore, displaying 2D slices out of the 3D data is still often the preferred visualization method. We present new combinations of photorealistic and nonphotorealistic rendering strategies for combined visualization of B-mode and color Doppler data, which are straightforward to implement, flexible, and suited for a wide range of US applications.