Conventional Two-dimensional Imaging Research Articles

Multi-Point Geostatistical Sedimentary Facies Modeling Based on Three-Dimensional Training Images

As an important modeling parameter in multi-point geostatistics, training images determine the modeling effect to a great extent. It is necessary to evaluate and optimize the applicability of candidate training images before modeling by multi-point geostatistics. Conventional two-dimensional training images can’t describe the overlapping relation of sedimentary facies in space, and there is a deficiency in describing the event relation of single data. This paper puts forward a new training image optimization method. The basic idea is to arrange and analyze sand bodies filled with sedimentary sand bodies in point dams and river channels in different periods. The method of obtaining three-dimensional training images is to use sand thickness maps and sedimentary facies maps for spatial constraints. The simulation test shows that compared with the sedimentary facies model obtained from two-dimensional training images, the sedimentary facies model obtained from three-dimensional training images through multi-point geostatistics has high compatibility and is more in line with geological understanding. On the basis of fully understanding the development characteristics of the sedimentary system and quantitative geometry of sedimentary body in the study area, sedimentary microfacies models based on sequential indicator simulation method and target simulation method are established, respectively. By comparing and analyzing the sedimentary microfacies models established by three different methods, the results show that the multi-point geostatistics can stably present the planar distribution characteristics and overlapping spatial relationship of sedimentary microfacies and reproduce the complex spatial structure and geometric shape of fluvial facies. The model established by this method is more in line with the geological sedimentary model.

Live-Cell Surface-Enhanced Raman Spectroscopy Imaging of Intracellular pH: From Two Dimensions to Three Dimensions.

Visualization of intracellular pH (i-pH) using surface-enhanced Raman spectroscopy (SERS) plays an important role toward understanding of cellular processes including their interactions with nanoparticles. However, conventional two-dimensional SERS imaging often fails to take into consideration changes occurring in the whole-cell volume. We therefore aimed at obtaining a comprehensive i-pH profile of living cells by means of three-dimensional (3D) SERS imaging, thereby visualizing dynamic i-pH distribution changes in a single cell. We devised here a biocompatible and highly stable SERS pH probe, comprising plasmonic gold nanostars functionalized with a pH-sensitive Raman reporter tag-4-mercaptobenzoic acid-and protected by a cationic biocompatible polymer, poly-l-arginine hydrochloride (PA). The positively charged PA coating plays a double role in enhancing cell uptake and providing chemical and colloidal stability in cellular environments. The SERS-active pH probe allowed visualization of local changes in i-pH, such as acidification during nanoparticle (NP) endocytosis. We provide evidence of i-pH changes during NP endocytosis via high-resolution 3D SERS imaging, thereby opening new avenues toward the application of SERS to intracellular studies.

Magnetic Resonance Imaging of Ankle Syndesmotic Ligament Injuries: Comparison of Three-dimensional Isotropic Intermediate-weighted Fast Spin Echo with Conventional Two-dimensional Imaging

Magnetic Resonance Imaging of Ankle Syndesmotic Ligament Injuries: Comparison of Three-dimensional Isotropic Intermediate-weighted Fast Spin Echo with Conventional Two-dimensional Imaging

Overview of three-dimensional integral imaging-based object recognition in low illumination conditions with visible range image sensors

We overview three-dimensional (3D) integral imaging-based object recognition in low illumination conditions. Imaging in very low illumination conditions, especially using passive, visible-range image sensors, remains a challenging endeavor that is particularly complicated by read-noise dominant images and provides unsatisfactory results when using conventional two-dimensional imaging strategies in photon-starved conditions. However, using passive three-dimensional integral imaging, which is optimal in a maximum likelihood sense, we are able to significantly improve imaging capabilities under low illumination conditions and allow for object detection and recognition. We overview reported work on 3D integral imaging object visualization, and recognition in low light including recent work utilizing convolutional neural networks for object recognition in very low illumination conditions.

Three-dimensional visualization of the alveolar bone and posterior superior alveolar foramen in gender.

The present study applied a three-dimensional (3D) program to measure the distances from the maxillary sinus floor (MSF) to the lingual and buccal alveolar bone and also to the posterior superior alveolar foramen (PSAF), with the aim of determining differences according to gender. The study also attempted to verify the accuracy of measurements obtained from 3D images by performing comparisons with the results obtained in a preliminary study. The results showed that the alveolar bone length and the MAF-PSAF were generally larger in males than in females. It is also predicted that the accuracy of data obtained from a 3D program will be higher than that of data derived from conventional two-dimensional (2D) images. The accurate measurements obtained in this study are anticipated to prove useful in assessments related to dental implantation and anatomical structures. The fundamental data obtained in this study may also assist in setting the goals of future studies utilizing 3D programs.

Accelerated metallic artifact reduction imaging using spectral bin modulation of multiacquisition variable-resonance image combination selective imaging

ObjectivesTo assess the clinical utility of a prototype sequence for metal artifact reduction, the multiacquisition variable–resonance image combination selective (MAVRIC-SL) at 3 T. This sequence allows a surgical prosthesis-dependent reduction in the number of spectral bins. We compared the prototype MAVRIC SL to the conventional two-dimensional fast spin-echo (FSE) sequences and MAVRIC SL images acquired with all spectral bins to those acquired with the optimized number of spectral bins. MethodsMAVRIC SL images were acquired in 25 image sets from August 2017 to April 2018. For each subject, the optimized number of spectral bins was determined using a short spectral calibration scan. The image sets obtained with magnetic resonance imaging that were used for the analysis consisted of MAVRIC-SL proton density (PD)-weighted or short inversion time inversion recovery (STIR) images acquired with all 24 spectral bins, the corresponding images with the optimized number of spectral bins, and the conventional two-dimensional FSE or STIR PD-weighted images. A musculoskeletal radiologist reviewed and scored the images using a five-point scale for artifact reduction around the prosthesis and visualization of the prosthesis and peri-prosthetic tissues. Quantitative evaluation of the peri-prosthetic tissues was also performed. The Wilcoxon rank-sum test was used to test for significance. ResultsThe MAVRIC SL images enabled a significantly improved reduction in metallic artifacts compared to the conventional two-dimensional FSE sequences. The optimized number of spectral bins ranged from 6 to 20, depending on the prosthesis susceptibility difference, size, and orientation to the B0 field. The scan times significantly decreased with a reduced number of spectral bins (354.0 ± 139.1 versus 283.0 ± 89.6 s; 20% reduced scan time; p < .05). Compared to the MAVRIC SL images acquired with all 24 bins, the artifact reduction and visualization of the prosthesis and peri-prosthetic tissues on the MAVRIC SL images acquired with calibrated bins were not significantly different. ConclusionsCompared to the MAVRIC SL images acquired with all 24 spectral bins, those acquired with an optimized number of spectral bins can reduce metallic artifacts with no significant image quality degradation while providing reduced scan time.

Inter-particle fluid flow visualisation of larger packed beds pertaining to heap leaching using X-ray computed tomography imaging

X-ray computed tomography (XCT) is a non-destructive 3-D imaging technique that permits visualisation of the internal structure within a sample, avoiding the stereological error found in conventional two-dimensional (2-D) image analysis. Its small-scale variant, in the present manuscript, referred to as X-ray micro-computed tomography (XMT) but more commonly referred to as µCT, has been widely studied for the characterisation of mineral particle beds, with a common focus in recent years being heap leaching applications. Several technical and computational factors have however limited the size of the configurations and samples studied with this methodology and thus CT flow path visualisation studies on packed beds larger than a few centimetres are uncommon in the literature. The methodology is also rarely used for fluid flow path identification, with other non-invasive alternatives being preferred. To remediate, the authors used a large medical XCT scanner to image a 266 * 200 * 100 mm3 rectangular bed configuration filled with non-porous 8 mm glass beads and porous 16–20 mm rock particles. The fluid flow was for its part imaged through the addition of Gastrografin®, a common medical contrast agent. Using Thermo Fisher Scientific's Avizo software, 3-D images of the beds, the liquid flows, as well as the pore networks were constructed and their parameters were computed. Validation experiments were also carried through ultraviolet (UV) fluorescence imaging using sodium fluorescein dye addition. By comparing the computed results of sphericity and equivalent diameter to the known values and the computed flow images to the UV fluorescence results, the authors conclude that their methodology is of adequate accuracy for further developments towards comprehensive analyses of unsaturated heap flow behaviour.

Impact of epicardial adipose tissue volume upon left ventricular dysfunction in patients with mild-to-moderate aortic stenosis: A post-hoc analysis.

BackgroundAortic stenosis (AS) may lead to diastolic dysfunction and later on heart failure (HF) with preserved left ventricular ejection fraction (HFpEF) via increased afterload and left-ventricular (LV) hypertrophy. Since epicardial adipose tissue (EAT) is a metabolically active fat depot that is adjacent to the myocardium and can influence cardiomyocytes and LV function via secretion of proinflammatory cytokines, we hypothesized that high amounts of EAT, as assessed by computed tomography (CT), may aggravate the development and severity of LV hypertrophy and diastolic dysfunction in the context of AS.MethodsWe studied 50 patients (mean age 71 ± 9 years; 9 women) in this preliminary study with mild or moderate AS and mild to severe LV diastolic dysfunction (LVDD), diagnosed by echocardiography, who underwent non-contrast cardiac CT and echocardiography. EAT parameters were measured on 2nd generation dual source CT. Conventional two-dimensional echocardiography and Tissue Doppler Imaging (TDI) was performed to assess LV function and to derive myocardial straining parameter. All patients had a preserved LV ejection fraction > 50%. Data was analysed using Pearson’s correlation.ResultsOnly weak correlation was found between EAT volume or density and E/é ratio as LVDD marker (r = -.113 p = .433 and r = .260, p = .068 respectively). Also, EAT volume or density were independent from Global Strain Parameters (r = 0.058 p = .688 and r = -0.207 p = .239). E/é ratio was strongly associated with LVDD (r = .761 p≤0.0001) and Strain Parameters were moderately associated with LV Ejection Fraction (r = -.669 p≤0.001 and r = -.454 P≤0.005).ConclusionsIn this preliminary study in patients with AS, the EAT volume and density as assessed by CT correlated only weakly with LVDD, as expressed by the commonly used E/é ratio, and with LV strain function. Hence, measuring EAT volume and density may neither contribute to the prediction nor upon the severity of LVDD, respectively.

Evaluation of right ventricle functions might be a method for early recognizing cardiotoxicity in hematopoietic stem cell transplantation

Objective: We aimed to investigate whether right ventricular (RV) functional assessment by echocardiography may help in the early diagnosis of hematopoietic stem cell transplantation (HSCT)-induced cardiotoxicity. Methods: Our study population comprised 41 autologous multiple myeloma, 25 autologous Hodgkin's lymphoma, 20 autologous and 19 allogeneic non-Hodgkin's lymphoma, 10 allogeneic acute myeloid leukemia, 12 allogeneic myelodysplastic syndrome, and 10 allogeneic aplastic anemia patients. Conventional two-dimensional echocardiographic and tissue Doppler imaging examination of the patients were performed before and after HSCT. Post-HSCT values were compared with pre-HSCT values. Results: The mean age of the patients was 46.51 ± 16.24 years, and the mean hospital length of stay and the mean leukocyte engraftment time were 30 and 11 days, respectively. The number of female and male patients was 60 (43.8%) and 77 (56.2%), respectively. There were no significant differences in echocardiographic parameters including left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left ventricular ejection fraction, RV, right atrium, pulmonary artery pressure, pulmonary velocity, Pulmonary acceleration time (PAT)/ pulmonary ejection time (PET), PAT, E, A wave velocity, E/A ratio, and DT and A' velocity before and after HSCT. Compared to pretransplant values, posttransplant values of the E' velocity, S' velocity, E'/A' ratio, and tricuspid annular plane systolic excursion showed a statistically significant decrease (0.15 ± 0.34 vs. 0.12 ± 0.04, P = 0.032; 0.19 ± 0.06 vs. 0.09 ± 0.04, P

FisheyeDet: A Self-Study and Contour-Based Object Detector in Fisheye Images

Fisheye Images have attracted increasing attention from the research community due to their large field of view (LFOV). However, the geometric transformations inherent in fisheye cameras result in unknown spatial distortion and large variations in the appearance of objects. And this fact leads to poor performance of the state-of-the-art methods in conventional two-dimensional (2D) images. To address this problem, we propose a self-study and contour-based object detector in fisheye images, named FisheyeDet. The No-prior Fisheye Representation Method is proposed to guarantee that the network adaptively extracts distortion features without prior information such as prespecified lens parameters, special calibration patterns, etc. Furthermore, in order to tightly and robustly localize objects in fisheye images, the Distortion Shape Matching strategy is proposed, which invokes the irregular quadrilateral bounding boxes based on the contour of distorted objects as the core. By combining with the “No-prior Fisheye Representation Method” and “Distortion Shape Matching”, our proposed detector builds an end-to-end network. Finally, due to the lack of public fisheye datasets, we are on the first attempt to create a multi-class fisheye dataset VOC-Fisheye for object detection. Our proposed detector shows favorable generalization ability and achieves 74.87% mAP (mean average precision) on the VOC-Fisheye, outperforming the existing state-of-the-art methods.

Space-slice ion imaging: High slice resolution imaging in the polarization plane of arbitrarily polarized ionizing light

We present a conceptually new, slit-based slice imaging technique for ion-imaging experiments, offering a way for high slice resolution imaging in the polarization plane of an ionizing laser pulse. In the present method, a mechanically adjustable slit is installed in the drift region of the flight of the ions so that only a thin central slice of a three-dimensionally expanding ion cloud (Newton sphere) passes through the slit. The sliced cloud is then projected onto a two-dimensional position-sensitive ion detector installed parallel to the slice plane. Compared to the conventional two-dimensional imaging, the present “space-slice imaging” scheme has two principle novelties: (1) The slit acts as an ideal gate for the slicing, and a slice resolution of 1% or higher can be achieved, in principle, using submillimeter slit width for a typical a few-centimeter ion cloud. (2) The imaging plane can be automatically parallel to the polarization plane of a laser pulse regardless of the state of polarization, resulting in a hitherto unrealized “camera angle.” We developed a space-slice ion imaging apparatus to realize and validate the present scheme. To evaluate its performance, we carried out the Coulomb explosion imaging of the N2 molecule. By adjusting slit width, slicing up to approximately 0.33% was achieved without remarkable image distortion. The polarization-dependent imaging shows that the ejection angles of ions can be directly read from the observed images obtained with any polarization states. The present imaging measurements in the laser polarization plane opens new avenues for the study of laser-induced dynamics; these dynamics cannot be fully characterized with the existing two-dimensional setups. As an example, we applied the present approach to the time-resolved imaging of a laser-driven rotational wave packet of N2, using a circularly polarized exploding pulse as an isotropic probe in the imaging plane. We successfully observed clear time-dependent images containing full spatiotemporal information of the wave packet dynamics. Details of the concept, design, and operation of our apparatus are presented in the present paper.

Blind Quality Assessment of 3-D Synthesized Views Based on Hybrid Feature Classes

In this paper, a novel quality metric to evaluate depth-based synthesized views is proposed. This metric relies on a hybrid approach that uses features extracted in different phases of the image synthesis procedure, namely from the bitstream, from intermediate data produced during the synthesis process, and from the final synthesized view; these features are then combined using support vector regression. A new data set of synthesized images, with compression and rendering artifacts, was built and used to develop and assess the proposed metric. The metric performance is compared with conventional full-reference two-dimensional image quality assessment metrics and with quality assessment metrics developed specifically for synthesized images. The experimental results showed that the proposed solution outperforms the considered benchmark metrics, being able to predict the subjective quality scores of the synthesized images with a Pearson correlation coefficient close to 0.9.

Comparison of enhanced laparoscopic imaging techniques in endometriosis surgery: a diagnostic accuracy study

BackgroundFor surgical endometriosis, treatment key is to properly identify the peritoneal lesions. The aim of this clinical study was to investigate if advanced imaging improves the detection rate by comparing narrow-band imaging (NBI), near-infrared imaging with indocyanine green (NIR-ICG), or three-dimensional white-light imaging (3D), to conventional two-dimensional white-light imaging (2D) for the detection of peritoneal endometriotic lesions.MethodsThis study was a prospective, single-center, randomized within-subject, clinical trial. The trial was conducted at Amsterdam UMC—Location VUmc, a tertiary referral hospital for endometriosis. 20 patients with ASRM stage III–IV endometriosis, scheduled for elective laparoscopic treatment of their endometriosis, were included. During laparoscopy, the pelvic region was systematically inspected with conventional 2D white-light imaging followed by inspection with NBI, NIR-ICG, and 3D imaging in a randomized order. Suspected endometriotic lesions and control biopsies of presumably healthy peritoneum were taken for histological examination. The pathologist was blinded for the method of laparoscopic detection. Sensitivity and specificity rates of the enhanced imaging techniques were analyzed. McNemar’s test was used to compare sensitivity to 2D white-light imaging and Method of Tango to assess non-inferiority of specificity.ResultsIn total, 180 biopsies were taken (117 biopsies from lesions suspected for endometriosis; 63 control biopsies). 3D showed a significantly improved sensitivity rate (83.5% vs. 75.8%, p = 0.016) and a non-inferior specificity rate (82.4% vs. 84.7%, p = 0.009) when compared to 2D white-light imaging. The single use of NBI or NIR-ICG showed no improvement in the detection of endometriosis. Combining the results of 3D and NBI resulted in a sensitivity rate of 91.2% (p < 0.001).ConclusionEnhanced laparoscopic imaging with 3D white light, combined with NBI, improves the detection rate of peritoneal endometriosis when compared to conventional 2D white-light imaging. The use of these imaging techniques enables a more complete laparoscopic resection of endometriosis.

X-ray Microcomputed Tomography (µCT) for Mineral Characterization: A Review of Data Analysis Methods

The main advantage of X-ray microcomputed tomography (µCT) as a non-destructive imaging tool lies in its ability to analyze the three-dimensional (3D) interior of a sample, therefore eliminating the stereological error exhibited in conventional two-dimensional (2D) image analysis. Coupled with the correct data analysis methods, µCT allows extraction of textural and mineralogical information from ore samples. This study provides a comprehensive overview on the available and potentially useful data analysis methods for processing 3D datasets acquired with laboratory µCT systems. Our study indicates that there is a rapid development of new techniques and algorithms capable of processing µCT datasets, but application of such techniques is often sample-specific. Several methods that have been successfully implemented for other similar materials (soils, aggregates, rocks) were also found to have the potential to be applied in mineral characterization. The main challenge in establishing a µCT system as a mineral characterization tool lies in the computational expenses of processing the large 3D dataset. Additionally, since most of the µCT dataset is based on the attenuation of the minerals, the presence of minerals with similar attenuations limits the capability of µCT in mineral segmentation. Further development on the data processing workflow is needed to accelerate the breakthrough of µCT as an analytical tool in mineral characterization.

Optical spatial differentiator for a synthetic three-dimensional optical field.

We propose a grating-based spatial differentiator to process a synthetic three-dimensional optical field, where several conventional two-dimensional optical images are stacked at multiple wavelengths. The device simultaneously enables both spatial differentiation and demultiplexing during light diffraction. We show the spatial differentiation resulting from coupling and interference of spatial modes and derive the theoretical condition for spatial differentiation based on spatial coupled-mode theory. We numerically investigate field transformation during diffraction and demonstrate spatial differentiation with image processing of edge detection for a synthetic three-dimensional optical field, where four images are stored at different wavelengths.

Transcatheter Mitral Valve Planning and the Neo-LVOT: Utilization of Virtual Simulation Models and 3D Printing.

Transcatheter mitral valve replacement (TMVR) is an emerging alternative for patients with severe mitral valve regurgitation who are considered at high risk for conventional surgical options. The early clinical experience with TMVR has shown that pre-procedural planning with computed tomography (CT) is needed to mitigate the risk of potentially lethal procedural complications such as left ventricular outflow tract (LVOT) obstruction. The goal of this review is to provide an overview of key concepts relating to TMVR pre-procedural planning, with particular emphasis on imaging-based methods for predicting TMVR-related LVOT obstruction. Risk of LVOT obstruction can be assessed with CT-based pre-procedural planning by using virtual device simulations to estimate the residual 'neo-LVOT' cross-sectional area which remains after device implantation. A neo-LVOT area of less than 2cm2 is currently thought to increase the risk of obstruction; however, additional studies are needed to further validate this cutoff value. Three-dimensional printing and personalized computational simulations are also emerging as valuable tools which may offer insights not readily confered by conventional two-dimensional image analysis. The simulated neo-LVOT should be routinely assessed on pre-procedural CT when evaluating anatomical suitability for TMVR.

CBCT in orthodontics: a systematic review on justification of CBCT in a paediatric population prior to orthodontic treatment.

SummaryBackgroundTaking into account radiation doses, safety, and protection, we highlighted the features in which cone-beam computed tomography (CBCT) can offer an advantage compared to the conventional two-dimensional imaging in paediatric dentistry before orthodontic treatment.ObjectiveThe aim of this article was to conduct a systematic review to assess the diagnostic efficacy of CBCT in the paediatric population at a pre-orthodontic phase.Search methodsMEDLINE via PubMed was searched to identify all peer-reviewed articles potentially relevant to the review until 1 July 2018. Relevant publications were selected by two reviewers independently.Selection criteriaThe literature selection for this systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was based on predetermined inclusion criteria.Data collection and analysisData were collected on overall study characteristics and examination characteristics of the selected studies. Methodological quality of the selected studies was evaluated. Original studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Thereafter, levels of evidence were obtained according to Grading of Recommendations Assessment, Development and Evaluation criteria.ResultsAs a result of the QUADAS assessment, a total of 37 articles were included in the protocol. Following a proper protocol, CBCT was regarded as a reliable tool for assessment and management of impacted canine and root fracture. It provided a better evaluation of normal and pathological condylar shape and volume. CBCT was a superior choice for pre-surgical diagnostic applications in cleft lip and/or palate over a medical computed tomography based on its lower radiation exposure, shorter investigation time, and low purchase costs.ConclusionsCBCT is justified only in those cases where conventional radiography fails to provide a correct diagnosis of pathology. Therefore, it cannot be regarded as a standard method of diagnosis. CBCT imaging may also be justified when it positively affects treatment options or provides treatment optimization.RegistrationNone.Conflict of interestNone to declare.

Artificial intelligence assistance for fetal head biometry: Assessment of automated measurement software.

To evaluate the feasibility and reproducibility of artificial intelligence software (Smartplanes®) to automatically identify the transthalamic plane from 3D ultrasound volumes and to measure the biparietal diameter (BPD) and head circumference (HC) in fetus. Thirty fetuses were evaluated at 17-30 weeks' gestation. For each fetus two three-dimensional (3D) volumes of the fetal head along with one conventional two-dimensional (2D) image of the transthalamic plane were prospectively acquired. The Smartplanes® software identified the transthalamic plane from the 3D volumes and performed BPD and HC measurements automatically (3D auto). Two experienced sonographers also measured BPD and HC from 2D images and from the 3D volumes. Measurements were compared using Bland-Altman plots. Interclass correlation coefficient (ICC) was used to evaluate intra- and interobserver reproducibility. For each series of measurements, intra- and interobserver reproducibility rates were high with ICC values>0.98. The 95% confidence intervals between the BPD measurements were 2mm (3D versus 2D) and 4mm (3D auto versus 2D) and the HC measurements were 7.5mm (3D versus 2D) and 11mm (3D auto versus 2D). Fetal head measurements obtained automatically by Smartplanes® software from 3D volumes show good agreement with those obtained by two experienced sonographers from conventional 2D images and 3D volumes. The reproducibility of these measurements is similar to that observed by experienced sonographers.

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver.

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip's spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip's spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.