Case presented by Rtishchev Anton and Zaiko Valeriy from Academician V.I. Shumakov Federal Research Center of Transplantology and Artificial Organs, Russian Federation
Currently, the only way to cure liver diseases in their final stages is through liver transplantation. In order for the surgeon to both cure the patient and not harm the donor, the preoperational assessment of the transplantation efficiency needs to be highly accurate. Furthermore, the success of the surgery depends on the volume of the donor's liver, the transplant, and the interposition of major vessels. The Mimics Innovation Suite conveniently provides researchers with in-depth information about the patient's anatomy, thus providing valuable background information when assessing the transplantation and liver tumor surgery.
Assessing a Liver Transplantation Using the Mimics® Innovation Suite
In the case of living relative donor transplantation, the volume of liver tissue plays a critical role. To prevent post-operative liver deficiency, the size of the tissue, which is well supplied with blood from the donor and transplanted into the recipient, should correlate to their body weight. Researchers use the fast and accurate segmentation tools contained in the Mimics Innovation Suite to convert CT data to 3D models. This provides the surgeon with a 3D reconstruction of the liver tissue and major vessels, which can then be virtually cut in order to study optimal resection conditions, minimizing the risk of intra-operative blood loss and reducing the surgical time and rehabilitation period for the patients.
Visualizing the Liver Tumor Resection Using 3D Models
Tumor resection surgery requires very thorough preoperational planning because of the complexity of the cutting plane. The main challenge for the surgeon is to choose the optimal way to cut the liver tissue and perform a total tumor resection, minimizing the risk of blood loss during the surgery and postoperative perfusion. To accurately assess such a liver tumor resection, researchers can use 3D models made with the Mimics Innovation Suite to analyze the spatial position of the tumor with respect to major vessels, and virtually cut the liver tissue using a cutting plane.
Obtaining a 3D Reconstruction from Ultrasound Data
To obtain anatomical data without contraindications in a fast and safe way, an ultrasound is conducted during the preoperative period. Conventionally, 2D ultrasounds are used, but recently volumetric 3D ultrasound has increased in popularity. Exporting the data as a Cartesian grid, the 3D ultrasound images can be imported into the Mimics Innovation Suite. Although images obtained using ultrasound are not as informative or as easy to analyze as those obtained by CT or MRI, the 3D reconstruction from ultrasound data created in the Mimics Innovation Suite yields a comprehensive and accurate outcome. To further increase the accuracy of the ultrasound image, researchers have developed a novel method to combine multiple scans. The resulting stack is loaded to the Mimics Innovation Suite, where the surgeon can then accurately segment and design the images, resulting in an informative 3D reconstruction of the ultrasound data.
Verifying the Accuracy
3D models of tumor and great vessels obtained via ultrasound (respectively in pink and purple) are merged with 3D models obtained via CT (respectively in green and khaki) and show accuracy of ultrasound reconstruction3D models of tumor and great vessels obtained via ultrasound (respectively in pink and purple) are merged with 3D models obtained via CT (respectively in green and khaki) and show accuracy of ultrasound reconstruction
Researchers confirm the accuracy by merging the ultrasound 3D reconstruction with one developed from CT imaging. The 3D reconstruction from ultrasound data is used to support the CT data as part of the preoperative process. This allows for the size and position of the liver tumor to be confirmed. The reconstruction can also be used to observe the dynamics of the tumor growth without the need for numerous CT scans and the associated radiation. Furthermore, a comparison of 3D models obtained via ultrasound data versus via traditional CT scans shows that the ultrasound 3D reconstruction is an appropriate alternative method to analyze anatomical data.
3D Ultrasound Import in Mimics Research 17.0
Mimics Research 17.0 introduces a user-friendly import of 3D ultrasound image stacks, broadening the range of applications that can be addressed with the Mimics Innovation Suite tools. Thanks to the cost and radiation benefits of ultrasound, Mimics users can explore new ways of Engineering on Anatomy.
The standard in 'Engineering on Anatomy'
The Mimics Innovation Suite turns 3D image data into high quality digital models in an accurate and efficient way. Starting from CT, MRI or 3D Ultrasound images, the Mimics Innovation Suite offers the most advanced image segmentation, the broadest anatomical measurement options, powerful CAD tools for Engineering on Anatomy and 3D Printing, and accurate model preparation for FEA and CFD.
In this case study, the authors used the Mimics Innovation Suite to accurately assess living donor liver transplantation using the following steps:
Segment CT and ultrasound images into an accurate 3D model
Virtually assess the optimal conditions for liver tumor resection
Regulatory Information:
Mimics Innovation Suite currently consists of the following medical device software components: Mimics version 16 and 3-matic version 8 (released 2013). Mimics is intended for use as a software interface and image segmentation system for the transfer of imaging information from a medical scanner such as a CT scanner or a Magnetic Resonance Imaging scanner. It is also used as pre-operative software for simulating /evaluating surgical treatment options. 3-matic is intended for use as software for computer assisted design and manufacturing of medical exo- and endo‑prostheses, patient‑specific medical and dental/orthodontic accessories and dental restorations.
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