3D/ 4D ultrasound

We would like to invite you to join this exciting new project as a chapter contributor. Since this is a textbook, a great deal of this chapter entails a survey on the topic under the paradigm of cyber-physical systems, what can be done onboard and remotely, the distributed nature of the system and some exercises on futurology (anticipating trends can shed some light on upcoming designs). IET will bring great visibility to your work. You are welcome to suggest another topic/chapter title if you feel it would be more suitable. Each chapter should be around 20-25 pages each and can be submitted as a Word or Latex File. The IET will send you additional information (formatting, permission form, etc.) with the contributor's agreement once you have agreed to contribute to the book. Visit http:// www.theiet.org/resources/author-hub/books/index.cfm to get all information you need as a contributor to an IET research-level book. Each book is expected to have a total number of 500 printed pages (based on approximately 550 words per page with a 20% allowance for figures and tables). We have included a tentative schedule and list of topics below. If this is something you would consider, please send me the title of your chapter, a short description/abstract of the chapter content, and your full contact details. We will expect original content and new results for this book. You can, of course, reuse published material but the percentage of material reuse for the chapter should be less than 40%. The IET will run a piracy software on the full manuscript to control that you are including original material and will reject chapters who contain a large amount of already-published material so please do take this into consideration.

Abstract: By appropriating both medical and communication technologies, the gender- reveal party has recently emerged as a ritual performance centered on a dramatically staged disclosure of the sex of a gestating fetus. The gender-reveal party is an example of the new forms of ritualization that take place during pregnancy in 21st-century North America. Typically, the focal point of the party is when the future parents cut a cake whose inside color (blue or pink) reveals the sex of the fetus. This article examines the ritual dynamics and creativity at work in the preparation, the performance and the mediated dissemination of this festive occasion. Key elements of the ritual will be described, as well as its conditions of emergence in a context where neither medical nor religious institutions offer ritual options deemed appropriate enough for celebrating joyfully and emotionally during pregnancy.

Résumé : À travers une appropriation combinée de technologies médicales et des technologies de communication, la gender-reveal party (« la fête où l’on révèle le genre ») a récemment émergé comme une performance rituelle centrée sur la révélation par une mise en scène dramatique du sexe du fœtus en gestation. La gender-reveal party est un exemple des nouvelles formes de ritualisation qui prennent place pendant la grossesse au 21ème siècle en Amérique du Nord. Son point culminant consiste généralement à découper un gâteau dont la couleur intérieure (bleue ou rose) révèle le sexe du fœtus. Cet article examine les dynamiques rituelles et la créativité à l’œuvre dans la préparation, la performance et la dissémination médiatisée de cette occasion festive. Les éléments clés de ce rituel seront soulignés, ainsi que ses conditions d’émergence dans un contexte où ni les institutions médicales ni les institutions religieuses n’offrent d’options rituelles considérées comme appropriées pour des célébrations joyeuses et émotionnelles pendant la grossesse.

"We present the first description of real-time 3-dimensional ultrasound for insertion of a central venous catheter in a surgical patient. An HD11 XE™ ultrasound machine with a V8-4 transducer (Philips Medical Systems, Bothell, WA) was used throughout. Three-dimensional multiplanar and volume-rendered views allowed us to simultaneously view the neck anatomy in 3 orthogonal planes. Needle entry into the vein and subsequent catheter placement were also visualized. We were able to rotate the views in real time, thereby enabling visualization of the catheter within the lumen of the vein. The ability to see simultaneous real-time shortand long-axis views along with volume perspective without altering transducer position is an exciting development with the potential to confer a safety benefit to the patient. Although the operator is required to assimilate more information, the limitations we encountered were mainly related to processing power and transducer size, which we expect will be overcome with advancing technology.
"

Real-time target localization in ultrasound is useful in many clinical and scientific areas. For example in radiation therapy tumors can be localized in real-time and irradiated with a high accuracy. To measure the position of an ultrasound target in a global coordinate system or to extend the tracking volume by moving the ultrasound transducer an optical marker is attached to it and observed by an optical tracking system. The necessary calibration matrices from marker to ultrasound volume are obtained using hand-eye calibration algorithms which take sets of corresponding observations of the optical marker and an ultrasound target as input. The quality of these calibration matrices is highly dependent on the measured observations. While the accuracy of optical tracking systems is very high, accurate tracking in ultrasound is difficult because of the low resolution of the ultrasound volume, artifacts and noise. Therefore accurate hand-eye calibration is difficult between ultrasound and optical tracking systems. We have tested different phantoms, matching- and sub-pixel strategies to provide highly accurate tracking results in 3D ultrasound volumes as basis for hand-eye calibration. Tests have shown that – using the described methods - calibration results with RMS errors of less than 1mm between observed and calibrated targets can be reached.

Due to the required computational effort of 4D ultrasound imaging, such systems depend on low complexity techniques like nearest neighbor interpolation, which affects volume quality. Moreover, more accurate techniques like normalized convolution, backward trilinear interpolation, and forward spherical and ellipsoidal Gaussian kernel, are avoided in real-time imaging because of the tight reconstruction time. The goal of this work is to utilize recent commercial graphics hardware technology of graphics processing unit (GPU) to speed up the reconstruction time while increasing the quality of displayed volume.

Objectives: Recent advances in Spatial Temporal Image Correlation (STIC) 4 D fetal echocardiography include the application of eSTIC based on electronic probe image acquisition. We aimed to directly compare the performance of conventional STIC versus eSTIC technique (B-Mode and color Doppler imaging) during off-line reconstruction of STIC/eSTIC fetal heart volume pairs. Methods: Pairs of B-Mode and Color Doppler STIC volumes were acquired sequentially by firstly conventional (STIC) followed by electronic (eSTIC) probes during 33 consecutive obstetric scans at median 23 (range 13-31) gestational weeks. The resulting 66 fetal heart volume pairs were assessed blindly off-line by a fetal cardiologist who documented feasibility of reconstruction, presence of motion artifacts, subjective image quality on a 4-level scale: 1-best to 4-non-diagnostic and morphological diagnosis, to enable a paired comparison of STIC and eSTIC in the same fetus under similar scanning conditions. Results: eSTIC volumes had higher temporal resolution (37 vs. 24 frames per second, p < .001), less motion during acquisition (12 vs. 20 cases, O.R. 7.0, p ¼ .002) and better average image quality (1.9 vs. 2.2, p ¼ .006) compared to STIC volumes. More diagnostic reconstructions were achieved by eSTIC (n ¼ 55, 86%) than STIC (n ¼ 52, 78.8%), p ¼ .001), in a comparable analysis time (mean 4.96 vs. 4.94 min). During a comparison of image quality of the original acquisition (A) and reconstructed planes (B and C planes) e STIC was superior in 22 (33%), 39 (59%) and 21 (38%) volumes, respectively, with the remaining cases being of similar quality (<10% in each plane in favor of STIC). Imaging mode and gestational age had a similar impact on both eSTIC and STIC performance: diagnostically acceptable studies in 49 (75.8%) vs. 48 (72.2%) by B-Mode, 60 (90.9%) vs. 56 (84.8%) by Color Doppler Mode, 8 (62.5%) vs. 10 (50%) in early scans, 38 (95%) vs. 38 (95%) in mid-gestation scans, and 7 (70%) vs. 6 (60%) in third trimester scans. Eight obstetric scans identified a fetus with a cardiac variant or structural abnormality. Diagnostic concordance of the two STIC approaches was comparable (40/48 concordant interpretations, kappa 0.657) all confirmed by fetal and/or postnatal echocardiography. Conclusions: eSTIC was associated with more effective 4 D fetal heart reconstruction due to reduced motion artifacts and superior image quality in all planes, when compared to STIC. Early gestation reconstructions were not generally successful using either technology. Further study is needed to define the cost-effectiveness and diagnostic impact of eSTIC over conventional STIC and their role over, or in addition to, screening 2 D fetal echocardiography by appropriately trained sonographers.

Objectives: Recent advances in Spatial Temporal Image Correlation (STIC) 4 D fetal echocardiography include the application of eSTIC based on electronic probe image acquisition. We aimed to directly compare the performance of conventional STIC versus eSTIC technique (B-Mode and color Doppler imaging) during off-line reconstruction of STIC/eSTIC fetal heart volume pairs.
Methods: Pairs of B-Mode and Color Doppler STIC volumes were acquired sequentially by firstly conventional (STIC) followed by electronic (eSTIC) probes during 33 consecutive obstetric scans at median 23 (range 13–31) gestational weeks. The resulting 66 fetal heart volume pairs were assessed blindly off-line by a fetal cardiologist who documented feasibility of reconstruction, presence of motion artifacts, subjective image quality on a 4-level scale: 1-best to 4-non-diagnostic and morphological diagnosis, to enable a paired comparison of STIC and eSTIC in the same fetus under similar scanning conditions.
Results: eSTIC volumes had higher temporal resolution (37 vs. 24 frames per second, p < .001), less motion during acquisition (12 vs. 20 cases, O.R. 7.0, p = .002) and better average image quality (1.9 vs. 2.2, p = .006) compared to STIC volumes. More diagnostic reconstructions were achieved by eSTIC (n = 55, 86%) than STIC (n = 52, 78.8%), p = .001), in a comparable analysis time (mean 4.96 vs. 4.94 min). During a comparison of image quality of the original acquisition (A) and reconstructed planes (B and C planes) e STIC was superior in 22 (33%), 39 (59%) and 21 (38%) volumes, respectively, with the remaining cases being of similar quality (<10% in each plane in favor of STIC). Imaging mode and gestational age had a similar impact on both eSTIC and STIC performance: diagnostically acceptable studies in 49 (75.8%) vs. 48 (72.2%) by B-Mode, 60 (90.9%) vs. 56 (84.8%) by Color Doppler Mode, 8 (62.5%) vs. 10 (50%) in early scans, 38 (95%) vs. 38 (95%) in mid-gestation scans, and 7 (70%) vs. 6 (60%) in third trimester scans. Eight obstetric scans identified a fetus with a cardiac variant or structural abnormality. Diagnostic concordance of the two STIC approaches was comparable (40/48 concordant interpretations, kappa 0.657) all confirmed by fetal and/or postnatal echocardiography.
Conclusions: eSTIC was associated with more effective 4 D fetal heart reconstruction due to reduced motion artifacts and superior image quality in all planes, when compared to STIC. Early gestation reconstructions were not generally successful using either technology. Further study is needed to define the cost-effectiveness and diagnostic impact of eSTIC over conventional STIC and their role over, or in addition to, screening 2 D fetal echocardiography by appropriately trained sonographers.

An important aspect for an improved cardiac functional analysis is the accurate segmentation of the left ventricle (LV). A novel approach for fully-automated segmentation of the LV endocardium and epicardium contours is presented. This is mainly based on the natural physical characteristics of the LV shape structure. Both sides of the LV boundaries exhibit natural elliptical curvatures by having details on various scales, i.e. exhibiting fractal-like characteristics. The fractional Brownian motion (fBm), which is a non-stationary stochastic process, integrates well with the stochastic nature of ultrasound echoes. It has the advantage of representing a wide range of non-stationary signals and can quantify statistical local self-similarity throughout the time-sequence ultrasound images. The locally characterized boundaries of the fBm segmented LV were further iteratively refined using global information by means of second-order moments. The method is benchmarked using synthetic 3D+time echocardiographic sequences for normal and different ischemic cardiomyopathy, and results compared with state-of-the-art LV segmentation. Furthermore, the framework was validated against real data from canine cases with expert-defined segmentations and demonstrated improved accuracy. The fBm-based segmentation algorithm is fully automatic and has the potential to be used clinically together with 3D echocardiography for improved cardiovascular disease diagnosis.