3D reconstructions of the cerebral ventricles and volume quantification in children with brain malformations

[Volumetry of the lateral ventricles in dogs: Examination of intra- and inter-rater reliability based on manual image segmentation]

Volumetric methods offer new approaches for the diagnosis and treatment of neurologic diseases, as well as for an improved assessment of prognosis. The aim of this study was to determine the intra- and inter-rater reliability of volumetric measurements in manual image segmentation of the lateral ventricles of dogs, taking different sequences, body mass and lateral ventricle size into account.MRI datasets of 9 dogs, representing 3 different body mass groups and 3 different ventricular size groups, were obtained retrospectively from the image database of our clinic. For each patient, 2D sequences were available in T2, T1 and FLAIR weighting in the transverse plane. The lateral ventricles were segmented and measured volumetrically 10 times each by 5 raters. A further 9 dogs were selected for evaluation of a 3D T1 sequence. One of the raters (JD) performed segmentation and measurement 10 times. Statistical analysis included descriptive data and calculation of intraclass correlation coefficient (ICC) for intra- and inter-rater reliability.Intra-rater reliability: The smallest variation in values was measured in the T1 sequence for dogs with small body mass and small ventricular size. For larger dogs and larger lateral ventricles, the 3D T1 sequence showed less variation. Only 2/36 calculated ICCs indicated moderate reliability (1 each for T1 and 3D T1 sequences). The remaining ICC (34/36) indicated poor reliability. Inter-rater reliability: The sequence with the least variation was observer dependent. All calculated ICCs (27/27) indicated poor reliability regardless of sequence, body mass or subjective ventricular size.Volumetric measurement of canine lateral ventricles by manual segmentation shows major weaknesses in terms of reliability, both for single and multiple examiner measurements.Manual segmentation as performed in this study is not suitable for routine clinical use due to poor reliability and time-consuming application.

Development of a Multi-Material 3D Printer for Functional Anatomic Models

Anatomic models are important in medical education and pre-operative planning as they help students or doctors prepare for real scenarios in a risk-free way. Several experimental anatomic models were made with additive manufacturing techniques to improve geometric, radiological, or mechanical realism. However, reproducing the mechanical behavior of soft tissues remains a challenge. To solve this problem, multi-material structuring of soft and hard materials was proposed in this study, and a three-dimensional (3D) printer was built to make such structuring possible. The printer relies on extrusion to deposit certain thermoplastic and silicone rubber materials. Various objects were successfully printed for testing the feasibility of geometric features such as thin walls, infill structuring, overhangs, and multi-material interfaces. Finally, a small medical image-based ribcage model was printed as a proof of concept for anatomic model printing. The features enabled by this printer offer a promising outlook on mimicking the mechanical properties of various soft tissues.

Biomaterials and 3D printing techniques used in the medical field

An implants' effectiveness depends upon the form of biomaterial used in its manufacture. A suitable material for implants should be biocompatible, sterile, mechanically stable and simple to shape. 3D printing technologies have been breaking new ground in the medical and medical industries in order to build patient-specific devices embedded in bioactive drugs, cells and proteins. Widespread use in medical 3D printing is a broad range of biomaterials including metals, ceramics, polymers and composites. Continuous work and developments in biomaterials used in 3D printing have contributed to significant growth of 3D printing applications in the production of personalised joints, prostheses, medication delivery system and 3D tissue engineering and regenerative medicine scaffolds. The present analysis focuses on the biomaterials used for therapeutic applications in different 3D printing technologies. Many specific forms of medical 3D printing technology are explored in depth, including fused deposition modelling, extrusion-based bioprinting, inkjet and poly-jet printing processes, their therapeutic uses, various types of biomaterial used today and the major shortcoming , are being studied in depth.

Three-dimension correction of Charcot ankle deformity with a titanium implant

BACKGROUND

Charcot neuroarthropathy of the ankle is an extremely challenging clinical dilemma, and its surgical management can be highly complicated. The goal of Charcot ankle treatment is to to restore a plantigrade and stable foot, and thus to avoid ulceration with subsequent infection. This report aims to introduce a method of correcting ankle deformity using a novel 3D printing technique.

PATIENT AND METHODS

One patient with Charcot ankle deformity was operated in this study. The ankle deformity of this patient was quantified in three dimensions through computed tomography. On the basis of the computed tomography scans, a new titanium implant was designed and manufactured using 3D printing. The implant was applied in the surgery of tibio-talo-calcaneal arthrodesis to restore local anatomy of the affected ankle of the patient with Charcot neuroarthropathy.

RESULTS

Evaluation of the post-operative radiography indicated union in the affected ankle. After surgery, the planar foot in this patient was restored. The patient was satisfied with the post-operative course, and joint fusion was successful as indicated by 2-year post-operative evaluation. The results of post-operative follow-up showed that the lower limb length of the patient with Charcot neuroarthropathy was salvaged, and the patient retained the plantigrade foot.

CONCLUSION

Three-dimensional printing technique combined with tibio-talo-calcaneal arthrodesis may help to correct ankle deformity in patients with Charcot neuroarthropathy.

Virtual and augmented reality: potential applications in radiology

The modern-day radiologist must be adept at image interpretation, and the one who most successfully leverages new technologies may provide the highest value to patients, clinicians, and trainees. Applications of virtual reality (VR) and augmented reality (AR) have the potential to revolutionize how imaging information is applied in clinical practice and how radiologists practice. This review provides an overview of VR and AR, highlights current applications, future developments, and limitations hindering adoption.

Development of Three-Dimensional Printed Craniocerebral Models for Simulated Neurosurgery

OBJECTIVE

To use three-dimensional (3D) printed craniocerebral models to guide neurosurgery and design the best operative route preoperatively.

METHODS

Computed tomography, magnetic resonance imaging, computed tomography angiography, and functional magnetic resonance images of the patients were collected as needed, reconstructed to form multicolor 3D craniocerebral images, and printed to form solid 3D models. The hollow aneurysm model was printed with rubberlike material; craniocerebral models were printed with resin or gypsum.

RESULTS

The 3D printed hollow aneurysm model was highly representative of what was observed during the surgery. The model had realistic texture and elasticity and was used for preoperative simulation of aneurysm clipping for clip selection, which was the same as was used during the surgery. The craniocerebral aneurysm model clearly showed the spatial relation between the aneurysm and surrounding tissues, which can be used to select the best surgical approach in the preoperative simulation, to evaluate the necessity of drilling the anterior clinoid process, and to determine the feasibility of using a contralateral approach. The craniocerebral tumor and anatomic model showed the spatial relation between tumor and intracranial vasculatures, tractus pyramidalis, and functional areas, which was helpful 1) when selecting the optimal surgical approach to avoid damage to brain function, 2) for learning the functional anatomy of the craniocerebral structure, and 3) for preoperative selection of surgical spaces in the sellar region.

CONCLUSIONS

3D printing provides neurosurgeons with solid craniocerebral models that can be observed and operated on directly and effectively, which further improves the accuracy of neurosurgeries.

Three-Dimensional Printing: Basic Principles and Applications in Medicine and Radiology

The advent of three-dimensional printing (3DP) technology has enabled the creation of a tangible and complex 3D object that goes beyond a simple 3D-shaded visualization on a flat monitor. Since the early 2000s, 3DP machines have been used only in hard tissue applications. Recently developed multi-materials for 3DP have been used extensively for a variety of medical applications, such as personalized surgical planning and guidance, customized implants, biomedical research, and preclinical education. In this review article, we discuss the 3D reconstruction process, touching on medical imaging, and various 3DP systems applicable to medicine. In addition, the 3DP medical applications using multi-materials are introduced, as well as our recent results.

3D-printing and the effect on medical costs: a new era?

3D-printing (3DP) is the art and science of printing in a new dimension using 3D printers to transform 3D computer aided designs (CAD) into life-changing products. This includes the design of more effective and patient-friendly pharmaceutical products as well as bio-inspired medical devices. It is poised as the next technology revolution for the pharmaceutical and medical-device industries. After decorous implementation scientists in collaboration with CAD designers have produced innovative medical devices ranging from pharmaceutical tablets to surgical transplants of the human face and skull, spinal implants, prosthetics, human organs and other biomaterials. While 3DP may be cost-efficient, a limitation exists in the availability of 3D printable biomaterials for most applications. In addition, the loss of skilled labor in producing medical devices such as prosthetics and other devices may affect developing economies. This review objectively explores the potential growth and impact of 3DP costs in the medical industry.

Three-dimensional Printing in Developing Countries

The advent of 3-dimensional (3D) printing technology has facilitated the creation of customized objects. The lack of regulation in developing countries renders conventional means of addressing various healthcare issues challenging. 3D printing may provide a venue for addressing many of these concerns in an inexpensive and easily accessible fashion. These may potentially include the production of basic medical supplies, vaccination beads, laboratory equipment, and prosthetic limbs. As this technology continues to improve and prices are reduced, 3D printing has the potential ability to promote initiatives across the entire developing world, resulting in improved surgical care and providing a higher quality of healthcare to its residents.

A plastic surgery application in evolution: three-dimensional printing

BACKGROUND

Three-dimensional printing represents an evolving technology still in its infancy. Currently, individuals and small business entities have the ability to manufacture physical objects from digital renderings, computer-aided design, and open source files. Design modifications and improvements in extrusion methods have made this technology much more affordable. This article explores the potential uses of three-dimensional printing in plastic surgery.

METHODS

A review was performed detailing the known uses of three-dimensional printing in medicine. The potential applications of three-dimensional printing in plastic surgery are discussed.

RESULTS

Various applications for three-dimensional printing technology have emerged in medicine, including printing organs, printing body parts, bio-printing, and computer-aided tissue engineering. In plastic surgery, these tools offer various prospective applications for surgical planning, resident education, and the development of custom prosthetics.

CONCLUSIONS

Numerous applications exist in medicine, including the printing of devices, implants, tissue replacements, and even whole organs. Plastic surgeons may likely find this technology indispensable in surgical planning, education, and prosthetic device design and development in the near future.

Three-dimensional anatomical accuracy of cranial models created by rapid prototyping techniques validated using a neuronavigation station

In neurosurgery and ear, nose and throat surgery the application of computerised navigation systems for guiding operations has been expanding rapidly. However, suitable models to train surgeons in using navigation systems are not yet available. We have developed a technique using an industrial, rapid prototyping process from which accurate spatial models of the cranium, its contents and pathology can be reproduced for teaching. We were able to register, validate and navigate using these models with common available navigation systems such as the Medtronic StealthStation S7®.

Virtual cerebral ventricular system: an MR-based three-dimensional computer model

The inherent spatial complexity of the human cerebral ventricular system, coupled with its deep position within the brain, poses a problem for conceptualizing its anatomy. Cadaveric dissection, while considered the gold standard of anatomical learning, may be inadequate for learning the anatomy of the cerebral ventricular system; even with intricate dissection, ventricular structures remain difficult to observe. Three-dimensional (3D) computer reconstruction of the ventricular system offers a solution to this problem. This study aims to create an accurate 3D computer reconstruction of the ventricular system with surrounding structures, including the brain and cerebellum, using commercially available 3D rendering software. Magnetic resonance imaging (MRI) scans of a male cadaver were segmented using both semiautomatic and manual tools. Segmentation involves separating voxels of different grayscale values to highlight specific neural structures. User controls enable adding or removing of structures, altering their opacity, and making cross-sectional slices through the model to highlight inner structures. Complex physiologic concepts, such as the flow of cerebrospinal fluid, are also shown using the 3D model of the ventricular system through a video animation. The model can be projected stereoscopically, to increase depth perception and to emphasize spatial relationships between anatomical structures. This model is suited for both self-directed learning and classroom teaching of the 3D anatomical structure and spatial orientation of the ventricles, their connections, and their relation to adjacent neural and skeletal structures.