Investigation of scattered dose in a mouse phantom model for pre-clinical dosimetry studies

Author(s):  
Amir Entezam ◽  
Andrew Fielding ◽  
Davide Moi ◽  
David Bradley ◽  
Gishan Ratnayake ◽  
...  
Keyword(s):  
Author(s):  
Jonathan Shapey ◽  
Thomas Dowrick ◽  
Rémi Delaunay ◽  
Eleanor C. Mackle ◽  
Stephen Thompson ◽  
...  

Abstract Purpose Image-guided surgery (IGS) is an integral part of modern neuro-oncology surgery. Navigated ultrasound provides the surgeon with reconstructed views of ultrasound data, but no commercial system presently permits its integration with other essential non-imaging-based intraoperative monitoring modalities such as intraoperative neuromonitoring. Such a system would be particularly useful in skull base neurosurgery. Methods We established functional and technical requirements of an integrated multi-modality IGS system tailored for skull base surgery with the ability to incorporate: (1) preoperative MRI data and associated 3D volume reconstructions, (2) real-time intraoperative neurophysiological data and (3) live reconstructed 3D ultrasound. We created an open-source software platform to integrate with readily available commercial hardware. We tested the accuracy of the system’s ultrasound navigation and reconstruction using a polyvinyl alcohol phantom model and simulated the use of the complete navigation system in a clinical operating room using a patient-specific phantom model. Results Experimental validation of the system’s navigated ultrasound component demonstrated accuracy of $$<4.5\,\hbox {mm}$$ < 4.5 mm and a frame rate of 25 frames per second. Clinical simulation confirmed that system assembly was straightforward, could be achieved in a clinically acceptable time of $$<15\,\hbox {min}$$ < 15 min and performed with a clinically acceptable level of accuracy. Conclusion We present an integrated open-source research platform for multi-modality IGS. The present prototype system was tailored for neurosurgery and met all minimum design requirements focused on skull base surgery. Future work aims to optimise the system further by addressing the remaining target requirements.


2021 ◽  
Vol 10 (12) ◽  
pp. 2721
Author(s):  
Nobuto Nakanishi ◽  
Shigeaki Inoue ◽  
Rie Tsutsumi ◽  
Yusuke Akimoto ◽  
Yuko Ono ◽  
...  

Ultrasound has become widely used as a means to measure the rectus femoris muscle in the acute and chronic phases of critical illness. Despite its noninvasiveness and accessibility, its accuracy highly depends on the skills of the technician. However, few ultrasound phantoms for the confirmation of its accuracy or to improve technical skills exist. In this study, the authors created a novel phantom model and used it for investigating the accuracy of measurements and for training. Study 1 investigated how various conditions affect ultrasound measurements such as thickness, cross-sectional area, and echogenicity. Study 2 investigated if the phantom can be used for the training of various health care providers in vitro and in vivo. Study 1 showed that thickness, cross-sectional area, and echogenicity were affected by probe compression strength, probe angle, phantom compression, and varying equipment. Study 2 in vitro showed that using the phantom for training improved the accuracy of the measurements taken within the phantom, and Study 2 in vivo showed the phantom training had a short-term effect on improving the measurement accuracy in a human volunteer. The new ultrasound phantom model revealed that various conditions affected ultrasound measurements, and phantom training improved the measurement accuracy.


1997 ◽  
Vol 4 (7) ◽  
pp. 508-512 ◽  
Author(s):  
Bruce L. Daniel ◽  
Robyn L. Birdwell ◽  
John W. Black ◽  
Debra M. Ikeda ◽  
Gary H. Glover ◽  
...  

Author(s):  
Jana S. Hopstaken ◽  
Leon de Jong ◽  
Jurgen J. Fütterer

Abstract Purpose For the safety and success of an ultrasound-guided percutaneous liver biopsy, needle visibility and needle tip identification are critical. The aim of this pilot study was to evaluate the influence of an innovative echogenic sheath placed over a standard biopsy needle on needle visibility in ultrasound imaging. Materials and methods Ultrasound videos of three sheaths with different coating characteristics (echogenicity) and one conventional liver biopsy needle were recorded at two angles (30° and 60°) and two depths (5 and 10 cm) in a human cadaver. The videos were blinded for needle type and presented to five independent radiologists who used Likert-scale scoring to rank each video for six characteristics on needle visibility. In addition, a phantom model was used to acquire standardized images for quantitative evaluation of the ultrasound visibility. Comparative statistical analysis consisted of a one-way ANOVA. Results The three prototype sheaths were ranked higher than the control needle at 60° with 5 cm depth, with an equal performance for the other conditions. The radiologists expressed more confidence in taking a biopsy with the echogenic sheaths than with the control needle, with 1 Likert score difference at 30°. Contrast analysis in the phantom model showed a statistically significant effect of a sheath (p = 0.004) on echogenic intensity. Conclusion This pilot study suggests that the use of an echogenic sheath may increase needle visibility, particularly for trajectories requiring steeper insertion angles. To investigate the superiority of the echogenic sheath over conventional needles, a clinical study is necessary.


Author(s):  
Katarzyna Ciosk ◽  
Andrzej Krawczyk ◽  
Hacer Oztura ◽  
Roman Kubacki

2018 ◽  
Vol 44 (12) ◽  
pp. 2768-2779
Author(s):  
Olivia Yau ◽  
Marie-France Hétu ◽  
Julia E. Herr ◽  
Michael A. Adams ◽  
Amer M. Johri

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