Fetal neuroimaging by transvaginal 3D ultrasound and MRI

Abstract Purpose Osteophytes are common radiographic markers of osteoarthritis. However, they are not accurately depicted using conventional imaging, thus hampering surgical interventions that rely on pre-operative images. Studies have shown that ultrasound (US) is promising at detecting osteophytes and monitoring the progression of osteoarthritis. Furthermore, three-dimensional (3D) ultrasound reconstructions may offer a means to quantify osteophytes. The purpose of this study was to compare the accuracy of osteophyte depiction in the knee joint between 3D US and conventional computed tomography (CT). Methods Eleven human cadaveric knees were pre-screened for the presence of osteophytes. Three osteoarthritic knees were selected, and then, 3D US and CT images were obtained, segmented, and digitally reconstructed in 3D. After dissection, high-resolution structured light scanner (SLS) images of the joint surfaces were obtained. Surface matching and root mean square (RMS) error analyses of surface distances were performed to assess the accuracy of each modality in capturing osteophytes. The RMS errors were compared between 3D US, CT and SLS models. Results Average RMS error comparisons for 3D US versus SLS and CT versus SLS models were 0.87 mm ± 0.33 mm (average ± standard deviation) and 0.95 mm ± 0.32 mm, respectively. No statistical difference was found between 3D US and CT. Comparative observations of imaging modalities suggested that 3D US better depicted osteophytes with cartilage and fibrocartilage tissue characteristics compared to CT. Conclusion Using 3D US can improve the depiction of osteophytes with a cartilaginous portion compared to CT. It can also provide useful information about the presence and extent of osteophytes. Whilst algorithm improvements for automatic segmentation and registration of US are needed to provide a more robust investigation of osteophyte depiction accuracy, this investigation puts forward the potential application for 3D US in routine diagnostic evaluations and pre-operative planning of osteoarthritis.

Download Full-text

3D ultrasound coronarography: first proof of concept study on isolated beating rat hearts

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.011 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

O Demeulenaere ◽

P Mateo ◽

P Sandoval ◽

O Villemain ◽

M Tanter ◽

...

Keyword(s):

Contrast Agents ◽

Flow Velocity ◽

Coronary Flow ◽

3D Ultrasound ◽

Frame Rate ◽

Doppler Imaging ◽

Coronary Perfusion ◽

Blood Flows ◽

Flow Reserve ◽

Rat Hearts

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Bettencourt Foundation Background/Introduction We demonstrated recently that Ultrafast ultrasound Doppler imaging can image the intramyocardial coronary circulation in beating hearts of large animals and patients [1]. Yet, ultrasound spatial resolution remains limited by wave physics and coronaries smaller than ∼100 µm could not be imaged. Ultrasound Localization Microscopy (ULM) [2] was recently introduced to tackle this issue and exploit the micrometric localization of microbubble contrast agents at ultrafast frame rate in order to image blood flows in micrometer vessels. Purpose The objective of this work was to demonstrate that 3D ultrafast ultrasound with contrast agents can provide the full 3D mapping of the coronary microcirculation with quantitative flow velocity on a beating rat heart. Methods Acquisitions were performed on ex vivo rat hearts (n = 5) with retrograde perfusion (Langendorff model). A flow of a Krebs–Henseleit solution mixed with a diluted microbubbles solution (0.22%) was perfused at controlled pressure into the coronary arteries (between 5 and 15 mL/min). We used a 32 × 32 elements, 8-MHz matrix-array ultrasound transducer connected to a 1024-channel programmable ultrasound scanner. An ultrafast Doppler imaging sequence consisting of 9 plane waves was transmitted at a PRF of 20 kHz during 270 ms and repeated 40 times. After beamforming and SVD clutter filtering, the microbubbles were localized and tracked in 3D. Flow velocity were mapped at baseline and after infusion of Adenosine (10e-5 µMol) at constant coronary perfusion pressure (120 mm Hg). Eventually, the hearts were fixed using formaldehyde perfusion and imaged by µCT after injection of radio opaque agent. Results We successfully imaged the coronary blood flows of entire rat hearts. It revealed the entire vasculature from large main coronaries arteries (cross section up to 1 mm) to small arterioles (smaller than 40 µm). Coronary flow velocities ranged from [1 – 50] cm/s depending on the arteries diameter. Velocity estimates were validated in vitro in tubes of Ø0.58mm and were in good agreement with theoretical values of a Poiseuille’s flow (relative ratio of 10% for maximum velocities). After Adenosine infusion, perfusion flow rates increased 102% ± 50% (p < 0.05) on average. Eventually, anatomy revealed by 3D ultrasound coronarography was in accordance with the anatomy revealed by the µCT. Conclusion(s) We demonstrated the feasibility of 3D ultrasound coronarography on isolated beating rat hearts. This technique has the potential to become a novel imaging tool to investigate the coronary micro-circulation and quantify non-invasively the Coronary Flow Reserve (CFR). Abstract Figure. Ultrasound coronarography

Download Full-text

Ultrasonographic 3D Evaluation in the Diagnosis of Bladder Endometriosis: A Prospective Comparative Diagnostic Accuracy Study

Gynecologic and Obstetric Investigation ◽

10.1159/000516634 ◽

2021 ◽

pp. 1-8

Author(s):

Fabio Barra ◽

Franco Alessandri ◽

Carolina Scala ◽

Simone Ferrero

Keyword(s):

Diagnostic Accuracy ◽

Three Dimensional ◽

3D Ultrasound ◽

Diagnostic Accuracy Study ◽

Extensive Experience ◽

Deep Endometriosis ◽

3D Reconstructions ◽

Analysis Group ◽

Bladder Endometriosis ◽

Accuracy Study

Objective: The use of three-dimensional (3D) transvaginal ultrasonography (TVS) has been investigated for the diagnosis of deep endometriosis (DE). This study aimed to evaluate if 3D reconstructions improve the performance of TVS) in assessing the presence and characteristics of bladder endometriosis (BE). Design: This was a single-center comparative diagnostic accuracy study. Participants/Materials, Setting, Methods: Patients referred to our institution (Piazza della Vittoria 14 Srl, Genova, Italy) with clinical suspicion of DE were included. In case of surgery, women underwent systematic preoperative ultrasonographic imaging; an experienced sonographer performed a conventional TVS; another experienced sonographer, blinded to results of the previous exam, performed TVS, with the addition of 3D modality. The presence and characteristics of BE nodules were described in accord with International DE Analysis group consensus. Ultrasound data were compared with surgical and histological results. Results: Overall, BE was intraoperatively found in 34 out of 194 women who underwent surgery for DE (17.5%; 95% confidence interval: 12.8–23.5%). TVS without and with 3D reconstructions were able to detect endometriotic BE in 82.2% (n = 28/34) and 85.3% (n = 29/34) of the cases (p = 0.125). Both the exams similarly estimated the largest diameter of BE (p = 0.652) and the distance between the endometriotic nodule and the closest ureteral meatus (p = 0.341). However, TVS with 3D reconstructions was more precise in estimating the volume of BE (p = 0.031). In one case (2.9%), TVS without and with 3D reconstructions detected the infiltration of the intramural ureter, which was confirmed at surgery and required laparoscopic ureterovesical reimplantation. Limitations: The extensive experience of the gynecologists performing the ultrasonographic scans, the lack of prestudy power analysis, and the population selected, which may have been influenced by the position of the institution as a referral center specialized in the treatment of severe endometriosis, are limitations of the current study. Conclusion: Our results demonstrated the high accuracy of ultrasound for diagnosing BE. The addition of 3D reconstructions does not improve the performance of TVS in diagnosing the presence and characteristics of BE. However, the volume of BE may be more precisely assessed by 3D ultrasound.

Download Full-text

Comparison between a novel 2D–3D ultrasound system (Accuro®) and conventional two-dimensional ultrasound for assessment of the lumbar spine: a prospective cohort study in volunteers

Canadian Journal of Anesthesia/Journal canadien d anesthésie ◽

10.1007/s12630-021-02063-6 ◽

2021 ◽

Author(s):

Juliana Caicedo ◽

Mrinalini Balki ◽

Cristian Arzola ◽

Naveed Siddiqui ◽

Xiang Y. Ye ◽

...

Keyword(s):

Cohort Study ◽

Lumbar Spine ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

3D Ultrasound ◽

Two Dimensional ◽

Ultrasound System

Download Full-text

Validation of Scolioscan Air-Portable Radiation-Free Three-Dimensional Ultrasound Imaging Assessment System for Scoliosis

Sensors ◽

10.3390/s21082858 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2858

Author(s):

Kelly Ka-Lee Lai ◽

Timothy Tin-Yan Lee ◽

Michael Ka-Shing Lee ◽

Joseph Chi-Ho Hui ◽

Yong-Ping Zheng

Keyword(s):

Ultrasound Imaging ◽

Imaging System ◽

Outcome Measurement ◽

Three Dimensional ◽

3D Ultrasound ◽

Mean Difference ◽

Assessment System ◽

Absolute Difference ◽

Data Sets ◽

Low Profile

To diagnose scoliosis, the standing radiograph with Cobb’s method is the gold standard for clinical practice. Recently, three-dimensional (3D) ultrasound imaging, which is radiation-free and inexpensive, has been demonstrated to be reliable for the assessment of scoliosis and validated by several groups. A portable 3D ultrasound system for scoliosis assessment is very much demanded, as it can further extend its potential applications for scoliosis screening, diagnosis, monitoring, treatment outcome measurement, and progress prediction. The aim of this study was to investigate the reliability of a newly developed portable 3D ultrasound imaging system, Scolioscan Air, for scoliosis assessment using coronal images it generated. The system was comprised of a handheld probe and tablet PC linking with a USB cable, and the probe further included a palm-sized ultrasound module together with a low-profile optical spatial sensor. A plastic phantom with three different angle structures built-in was used to evaluate the accuracy of measurement by positioning in 10 different orientations. Then, 19 volunteers with scoliosis (13F and 6M; Age: 13.6 ± 3.2 years) with different severity of scoliosis were assessed. Each subject underwent scanning by a commercially available 3D ultrasound imaging system, Scolioscan, and the portable 3D ultrasound imaging system, with the same posture on the same date. The spinal process angles (SPA) were measured in the coronal images formed by both systems and compared with each other. The angle phantom measurement showed the measured angles well agreed with the designed values, 59.7 ± 2.9 vs. 60 degrees, 40.8 ± 1.9 vs. 40 degrees, and 20.9 ± 2.1 vs. 20 degrees. For the subject tests, results demonstrated that there was a very good agreement between the angles obtained by the two systems, with a strong correlation (R2 = 0.78) for the 29 curves measured. The absolute difference between the two data sets was 2.9 ± 1.8 degrees. In addition, there was a small mean difference of 1.2 degrees, and the differences were symmetrically distributed around the mean difference according to the Bland–Altman test. Scolioscan Air was sufficiently comparable to Scolioscan in scoliosis assessment, overcoming the space limitation of Scolioscan and thus providing wider applications. Further studies involving a larger number of subjects are worthwhile to demonstrate its potential clinical values for the management of scoliosis.

Download Full-text