An autostereoscopic 3D display can improve visualization of 3D models from intracranial MR angiography.
ABSTRACT An autostereoscopic display with image quality comparable to ordinary 2D displays has recently been developed. The purpose of our study was to evaluate whether the visualization of static 3D models from intracranial time-of-flight (TOF) MR angiography (MRA) was improved by this display.
Maximum Intensity Projection (MIP) and Volume Rendering (VR) 3D models of intracranial arteries were created from ten TOF MRA datasets. Thirty-one clinically relevant intracranial arterial segments were marked in the TOF source images. A total of 217 markings were used. The markings were displayed in the 3D models as overlying red dots. Three neuroradiologists viewed the static 3D models on the autostereoscopic display, with the display operating either in autostereoscopic mode or in 2D mode. The task of the neuroradiologists was to correctly identify the marked artery. A paired comparison was made between arterial identification in autostereoscopic and 2D display mode.
In 314 MIP 3D models, 233 arterial markings (74%) were correctly identified with the display operating in autostereoscopic mode versus 179 (57%) in 2D mode. Odds ratio for correct identification with autostereoscopic mode versus 2D mode was 2.17 (95% confidence interval 1.55-3.04, P < 0.001). In 337 VR 3D models, 256 markings (76%) were correctly identified using autostereoscopic mode and 229 (68%) using 2D mode (odds ratio 1.49, 95% confidence interval 1.06-2.09, P = 0.021).
The visualization of intracranial arteries in static 3D models from TOF MRA can be improved by the use of an autostereoscopic display.
[Show abstract] [Hide abstract]
ABSTRACT: As stereoscopic display devices become common, their image quality assessment evaluation becomes increasingly important. Most studies conducted on 3D displays are based on psychophysics experiments with humans rating their experience based on detection tasks. The physical measurements do not map to effects on signal detection performance. Additionally, human observer study results are often subjective and difficult to generalize. We designed a computational stereoscopic observer approach inspired by the mechanisms of stereopsis in human vision for task-based image assessment that makes binary decisions based on a set of image pairs. The stereo-observer is constrained to a left and a right image generated using a visualization operator to render voxel datasets. We analyze white noise and lumpy backgrounds using volume rendering techniques. Our simulation framework generalizes many different types of model observers including existing 2D and 3D observers as well as providing flexibility to formulate a stereo model observer approach following the principles of stereoscopic viewing. This methodology has the potential to replace human observer studies when exploring issues with stereo display devices to be used in medical imaging. We show results quantifying the changes in performance when varying stereo angle as measured by an ideal linear stereoscopic observer. Our findings indicate that there is an increase in performance of about 13–18% for white noise and 20–46% for lumpy backgrounds, where the stereo angle is varied from 0 to 30. The applicability of this observer extends to stereoscopic displays used for in the areas of medical and entertainment imaging applications.Optics Express 09/2014; 22(19). DOI:10.1364/OE.22.022246 · 3.53 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Stereoscopic vision is a critical part of the human visual system, conveying more information than two-dimensional, monoscopic observation alone. This study aimed to quantify the contribution of stereoscopy in assessment of radiographic data, using widely available three-dimensional (3D)-capable display monitors by assessing whether stereoscopic viewing improved the characterisation of cerebral aneurysms. Nine radiology registrars were shown 40 different volume-rendered (VR) models of cerebral computed tomography angiograms (CTAs), each in both monoscopic and stereoscopic format and then asked to record aneurysm characteristics on short multiple-choice answer sheets. The monitor used was a current model commercially available 3D television. Responses were marked against a gold standard of assessments made by a consultant radiologist, using the original CT planar images on a diagnostic radiology computer workstation. The participants' results were fairly homogenous, with most showing no difference in diagnosis using stereoscopic VR models. One participant performed better on the monoscopic VR models. On average, monoscopic VRs achieved a slightly better diagnosis by 2.0%. Stereoscopy has a long history, but it has only recently become technically feasible for stored cross-sectional data to be adequately reformatted and displayed in this format. Scant literature exists to quantify the technology's possible contribution to medical imaging - this study attempts to build on this limited knowledge base and promote discussion within the field. Stereoscopic viewing of images should be further investigated and may well eventually find a permanent place in procedural and diagnostic medical imaging.Journal of Medical Imaging and Radiation Oncology 02/2014; 58(2). DOI:10.1111/1754-9485.12146 · 0.98 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Autostereoscopic visualization in clinical image-guided interventions and therapy poses constrains on the maximal latency in the visualization chain. In order to use visual feedback in the hand-eye coordinated loop, the latency of the visualization chain should be less than approximately 250–300 ms. This is a challenging constraint for interactive autostereoscopic multi-view volume rendering of large datasets. The various building blocks of such a visualization chain and their latency aspects are explored in this paper. Two complementary strategies to improve the latency of the entire chain are introduced and examined: lowering the resolution of the rendered views and reducing the amount of rendered views by smartly interpolating the missing views at receiver side. These strategies are balanced while optimizing the latency and image quality using a fuzzy logic approach. Furthermore, the optimal view resolution for a multi-view autostereoscopic lenticular display has been determined by investigating the lenticular lattice in the frequency domain. The quantitative aspects of the latency of the proposed building blocks and the resulting image quality have been measured.Neurocomputing 11/2014; 144:119–127. DOI:10.1016/j.neucom.2014.02.065 · 2.01 Impact Factor