Patient-specific Implants Improve Volumetric Surgical Accuracy Compared to Stock Reconstruction Plates in Modern Pardigm Virtual Surgical Planning of Fibular Free Flaps for Head and Neck Reconstruction.

BACKGROUND: Virtual surgical planning (VSP) for composite microvascular free flaps has become standard of care for oncologic head and neck reconstruction. Controversy remains as to the use of three-dimensional (3D)-printed titanium patient-specific implants (PSIs) versus hand-bent stock reconstruction plates. Proponents of PSIs cite improved surgical accuracy, reduced operative times, and improved clinical outcomes. Detractors purport increased cost associated with PSIs and presumed equivalent accuracy with less expensive stock plates. PURPOSE: The study purpose was to measure and compare the 3D-volumetric accuracy of PSI versus stock reconstruction plates among subjects undergoing VSP-guided mandibular fibular free flap reconstruction. STUDY DESIGN, SETTING, SAMPLE: A retrospective cohort study of subjects undergoing VSP-guided fibular free flap reconstructions at Mayo Clinic between 2016 and 2023 was performed. Subjects were excluded for non-VSP guidance, midfacial reconstruction, nonfibular free flaps, and lack of requisite study variables. PREDICTOR VARIABLE: The primary predictor was the type of reconstruction plate utilized (PSI vs stock plate). MAIN OUTCOME VARIABLE: The main outcome was volumetric surgical accuracy of the final reconstruction compared to the preoperative surgical plan by root mean square error (RMSE) calculation. Lower RMSE values indicated a higher surgical accuracy. COVARIATES: Covariates included age, sex, race, smoking status, American Society of Anesthesiologists Physical Status Classification System, Charlson Comorbidity Index, preoperative diagnosis, and number of fibular segments. ANALYSES: Differences in surgical accuracy were assessed between preoperative and postoperative segmented scans using volumetric overlays from which RMSE values were calculated. Univariate and multivariate modeling of plate type to RMSE calculation was performed. Statistical significance set to P < .05. RESULTS: Total of 130 subjects were identified, 105 PSI and 25 stock plates. Calculated mean RMSE in millimeters (mm) for stock plates was 1.46 (standard deviation: 0.33) and 1.15 (standard deviation: 0.36) for PSIs. Univariate modeling demonstrated a statistically significant difference in RMSE of 0.31 (95% confidence interval: 0.16-0.47) (P < .001) equating to a 21.2% (P < .001) improved volumetric surgical accuracy for PSIs. The association of improved volumetric accuracy with PSIs has been maintained in all multivariate models controlling for confounding. CONCLUSION AND RELEVANCE: In modern era VSP-guided head and neck fibular free flap reconstruction, patient-specific 3D-printed titanium implants confer a statistically significant improvement in volumetric surgical accuracy over stock reconstruction plates.

Creation and Validation of a Novel 3-Dimensional Pediatric Hip Ultrasound Model.

OBJECTIVES: The aim of this study was to create and validate a 3-dimensional (3D) ultrasound model with normal and abnormal pediatric hip joint anatomy that is comparable to a pediatric hip joint in appearance and anatomy and replicates sonographic characteristics of a pediatric hip joint. METHODS: A 3D rendering of the bone and soft tissue was created from a computed tomography pelvic scan of a pediatric patient. This rendering was modified to include a unilateral joint effusion. The bone was 3D printed with a photopolymer plastic, whereas the soft tissue was cast with a silicone mixture in a 3D-printed mold. The effusion was simulated by injecting saline into the soft tissue cavity surrounding the bone. The ultrasound model was validated by pediatric point-of-care ultrasonographers at an international pediatric ultrasound conference. RESULTS: A pediatric hip ultrasound model was developed that simulates both normal and abnormal pediatric hip joint anatomy, each with an appropriately sized, measurable joint effusion. Validation by pediatric point-of-care ultrasonographers showed that the key aspects of a normal pediatric hip joint (femoral physis, sloped femoral neck, and adequate soft tissue) with an identifiable and measurable effusion were included in the ultrasound model. CONCLUSIONS: In this study, we successfully created a cost-effective, reusable, and reproducible 3D pediatric hip ultrasound model. The majority of pediatric point-of-care ultrasonographers who evaluated the model agreed that this model is comparable to a pediatric patient for the purpose of teaching ultrasound skills and joint space measurement.

Photogrammetry scans for neuroanatomy education - a new multi-camera system: technical note.

Photogrammetry scans has directed attention to the development of advanced camera systems to improve the creation of three-dimensional (3D) models, especially for educational and medical-related purposes. This could be a potential cost-effective method for neuroanatomy education, especially when access to laboratory-based learning is limited. The aim of this study was to describe a new photogrammetry system based on a 5 Digital Single-Lens Reflex (DSLR) cameras setup to optimize accuracy of neuroanatomical 3D models. One formalin-fixed brain and specimen and one dry skull were used for dissections and scanning using the photogrammetry technique. After each dissection, the specimens were placed inside a new MedCreator® scanner (MedReality, Thyng, Chicago, IL) to be scanned with the final 3D model being displayed on SketchFab® (Epic, Cary, NC) and MedReality® platforms. The scanner consisted of 5 cameras arranged vertically facing the specimen, which was positioned on a platform in the center of the scanner. The new multi-camera system contains automated software packages, which allowed for quick rendering and creation of a high-quality 3D models. Following uploading the 3D models to the SketchFab® and MedReality® platforms for display, the models can be freely manipulated in various angles and magnifications in any devices free of charge for users. Therefore, photogrammetry scans with this new multi-camera system have the potential to enhance the accuracy and resolution of the 3D models, along with shortening creation time of the models. This system can serve as an important tool to optimize neuroanatomy education and ultimately, improve patient outcomes.

Extraocular muscle electromyographic recordings for intraoperative monitoring of cranial nerves III, IV, and VI: a single-center experience with intraorbital electrodes.

OBJECTIVE: The objective of this study was to describe the quantitative features of intraoperative electromyographic recordings obtained from cranial nerve III, IV, and VI neuromonitoring using 25-mm intraorbital electrodes, in the larger context of demonstrating the practicality of this technique during neurosurgical cases. METHODS: A 25-mm-long shaft-insulated intraorbital needle electrode is routinely used at the authors' institution for extraocular muscle (EOM) electromyographic monitoring of the inferior rectus, superior oblique, and/or lateral rectus muscles when their function is at risk. Cases monitored between January 1, 2021, and December 31, 2022, were reviewed for patient demographics, tumor location and pathology, EOMs monitored, pre- and postoperative examination, and complications from electrode placement. Compound muscle action potentials on triggered electromyography, as well as neurotonic discharges on free-run electromyography, were described quantitatively. RESULTS: There were 141 cases in 139 patients reviewed during the 24-month time span, with 278 EOMs monitored (inferior rectus/superior oblique/lateral rectus muscles 68/68/142). Triggered electromyography yielded biphasic or triphasic compound muscle action potentials from EOMs with a mean onset latency of 1.51 msec (range 0.94-3.22 msec), mean maximal peak-to-trough amplitude of 1073.93 µV (range 76.75-7796.29 µV), and high specificity for the channel in nearly all cases. Neurotonic discharges were recorded in 30 of the 278 EOMs (with all 3 muscles represented) and associated with a greater incidence of new or worsened ophthalmoparesis (OR 4.62, 95% CI 1.3-16.4). There were 2 cases of small periorbital ecchymosis attributed to needle placement; additionally, 1 case of needle-related intraorbital hematoma occurred after the review period. CONCLUSIONS: The 25-mm shaft-insulated intraorbital electrode facilitates robust and consistent electromyographic recordings of EOMs that are advantageous over existing techniques. Combined with the relative ease of needle placement and low rate of complications, the technique is practical for neuromonitoring during craniotomies.

Assessment of minimum target dose as a predictor of local failure after spine SBRT.

OBJECTIVES: Metastasis-directed stereotactic body radiation therapy (SBRT) has demonstrated robust clinical benefits in carefully selected patients, improving local control and even overall survival (OS). We assess a large database to determine clinical and dosimetric predictors of local failure after spine SBRT. METHODS: Spine SBRT treatments with imaging follow-up were identified. Patients were treated with a simultaneous integrated boost technique using 1 or 3 fractions, delivering 20-24 Gy in 1 fraction to the gross tumor volume (GTV) and 16 Gy to the low dose volume (or 27-36 Gy and 21-24 Gy for 3 fraction treatments). Exclusions included: lack of imaging follow-up, proton therapy, and benign primary histologies. RESULTS: 522 eligible spine SBRT treatments (68 % single fraction) were identified in 377 unique patients. Patients had a median OS of 43.7 months (95 % confidence interval: 34.3-54.4). The cumulative incidence of local failure was 10.5 % (7.4-13.4) at 1 year and 16.3 % (12.6-19.9) at 2 years. Local control was maximized at 15.3 Gy minimum dose for single-fraction treatment (HR = 0.31, 95 % CI: 0.17 - 0.56, p < 0.0001) and confirmed via multivariable analyses. Cumulative incidence of local failure was 6.1 % (2.6-9.4) vs. 14.2 % (8.3-19.8) at 1 year using this cut-off, with comparable findings for minimum 14 Gy. Additionally, epidural and soft tissue involvement were predictive of local failure (HR = 1.77 and 2.30). CONCLUSIONS: Spine SBRT offers favorable local control; however, minimum dose to the GTV has a strong association with local control. Achieving GTV minimum dose of 14-15.3 Gy with single fraction SBRT is recommended whenever possible.

MR Lymphangiography in Lymphatic Disorders: Clinical Applications, Institutional Experience, and Practice Development.

Lymphatic flow and anatomy can be challenging to study, owing to variable lymphatic anatomy in patients with diverse primary or secondary lymphatic pathologic conditions and the fact that lymphatic imaging is rarely performed in healthy individuals. The primary components of the lymphatic system outside the head and neck are the peripheral, retroperitoneal, mesenteric, hepatic, and pulmonary lymphatic systems and the thoracic duct. Multiple techniques have been developed for imaging components of the lymphatic system over the past century, with trade-offs in spatial, temporal, and contrast resolution; invasiveness; exposure to ionizing radiation; and the ability to obtain information on dynamic lymphatic flow. More recently, dynamic contrast-enhanced (DCE) MR lymphangiography (MRL) has emerged as a valuable tool for imaging both lymphatic flow and anatomy in a variety of congenital and acquired primary or secondary lymphatic disorders. The authors provide a brief overview of lymphatic physiology, anatomy, and imaging techniques. Next, an overview of DCE MRL and the development of an MRL practice and workflow in a hybrid interventional MRI suite incorporating cart-based in-room US is provided, with an emphasis on multidisciplinary collaboration. The spectrum of congenital and acquired lymphatic disorders encountered early in an MRL practice is provided, with emphasis on the diversity of imaging findings and how DCE MRL can aid in diagnosis and treatment of these patients. Methods such as DCE MRL for assessing the hepatic and mesenteric lymphatic systems and emerging technologies that may further expand DCE MRL use such as three-dimensional printing are introduced. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Projection of realistic three-dimensional photogrammetry models using stereoscopic display: A technical note.

The 3D stereoscopic technique consists in providing the illusional perception of depth of a given object using two different images mimicking how the right and left eyes capture the object. Both images are slightly different and when overlapped gives a three-dimensional (3D) experience. Considering the limitations for establishing surgical laboratories and dissections courses in some educational institutions, techniques such as stereoscopy and photogrammetry seem to play an important role in neuroanatomy and neurosurgical education. The aim of this study was to describe how to combine and set up realistic models acquired with photogrammetry scans in 3D stereoscopic projections. Three donors, one dry skull, embalmed brain and head, were scanned using photogrammetry. The software used for displaying the final realistic 3D models (Blender, Amsterdam, the Netherlands) is a free software and allows stereoscopic projection without compromising the interactivity of each model. By default, the model was exported and immediately displayed as a red cyan 3D mode. The 3D projector used in the manuscript required a side-by-side 3D mode which was set up with simple commands on the software. The final stereoscopy projection offered depth perception and a visualization in 360° of each donor; this perception was noted especially when visualizing donors with different cavities and fossae. The combination of 3D techniques is of paramount importance for neuroanatomy education. Stereoscopic projections could provide a valuable tool for neuroanatomy instruction directed at clinical trainees and could be especially useful when access to laboratory-based learning is limited.

Resection of a Solitary Right Ventricular Metastasis in Oligorecurrent Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC), constituting the predominant manifestation of liver cancer, stands as a formidable medical challenge. The prognosis subsequent to surgical intervention, particularly for individuals presenting with a solitary tumor, relies heavily on the degree of invasiveness. The decision-making process surrounding therapeutic modalities in such cases assumes paramount importance. This case report illuminates a rather unusual clinical scenario. Here, we encounter a patient who, following a disease-free interval, manifested an atypical presentation of HCC, specifically, a solitary cardiac metastasis. The temporal interval of remission adds an additional layer of complexity to the case. Through a multidisciplinary planning process, the decision was made for surgical removal of the metastatic tumor.

Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: neurosurgical and otolaryngologic conditions.

BACKGROUND: Medical three dimensional (3D) printing is performed for neurosurgical and otolaryngologic conditions, but without evidence-based guidance on clinical appropriateness. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides appropriateness recommendations for neurologic 3D printing conditions. METHODS: A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with neurologic and otolaryngologic conditions. Each study was vetted by the authors and strength of evidence was assessed according to published guidelines. RESULTS: Evidence-based recommendations for when 3D printing is appropriate are provided for diseases of the calvaria and skull base, brain tumors and cerebrovascular disease. Recommendations are provided in accordance with strength of evidence of publications corresponding to each neurologic condition combined with expert opinion from members of the 3D printing SIG. CONCLUSIONS: This consensus guidance document, created by the members of the 3D printing SIG, provides a reference for clinical standards of 3D printing for neurologic conditions.

Pre-eclampsia in a first pregnancy and subsequent pregnancy outcomes: a nationwide cohort study.

BACKGROUND: For women whose first pregnancy was complicated by pre-eclampsia (PE), particularly if severe and requiring early birth, the risk of recurrence and maternal and neonatal outcomes at subsequent birth are important considerations. METHODS: In this observational cohort study, all primiparous women who gave birth in Denmark between 1997 and 2016 were identified using nationwide registries. Women were stratified by whether they developed PE and followed from date of birth until subsequent birth, emigration, death or end of study (December 2016). The cumulative incidences of subsequent birth among women with versus without PE were assessed using the Aalen-Johansen estimator. Subsequent outcomes including PE recurrence and maternal and neonatal morbidity and mortality were also examined. Factors associated with subsequent birth and recurrent PE were examined using multivariable Cox regression models. RESULTS: Among 510 615 primiparous women with singleton pregnancies, 21 683 (4.2%) developed PE, with 1819 (0.4%) being early-onset PE (birth <34 weeks). Women with PE had a lower subsequent birth rate (57.4%) compared with women without PE (61.2%), and it was considerably lower among women with early-onset PE (49.4%). Among women with PE who had a subsequent birth, the overall recurrence rate of PE was 15.8% and higher among those with early-onset PE (31.5%). The gestational age increased with a median of 3 days (IQR -5 to 14) overall and 50 days (IQR 35-67) among those with early-onset PE. Moreover, neonatal and maternal morbidity and mortality were substantially improved in a subsequent pregnancy. CONCLUSIONS: Primiparous women with PE have a significantly lower rate of a subsequent birth than women without PE, yet the absolute difference was modest. Although the overall risk of recurrent PE is 1 in 6, maternal and neonatal morbidity and mortality at subsequent birth are substantially improved.

3D Printed Models of Trochlear Dysplasia and Trochleoplasty Simulation for Trainee Education.

Trochlear dysplasia is a major contributor to patellofemoral instability and subsequent failure of isolated soft tissue reconstruction procedures in the treatment of recurrent patellar dislocation and/or subluxation. Trochleoplasty procedures aim to address abnormal osseous trochlear morphologic factors that contribute to patellar maltracking. However, teaching these techniques is limited by the lack of reliable training models for trochlear dysplasia and trochleoplasty simulation. Although a cadaveric knee model of trochlear dysplasia for trochleoplasty simulation has been recently described, cadaveric knees are less amenable for use in trochleoplasty planning and surgeon training because of the absence of reliable, natural dysplastic anatomic relationships, such as suprapatellar spurs due to the rarity of dysplastic cadavers and the high cost of cadaveric specimens. Furthermore, readily available sawbone models represent "normal" osseous trochlear morphology and are difficult to modify and bend due to their material composition. Given this, we have developed a cost-effective, reliable, and anatomically accurate three-dimensional (3D) knee model of trochlear dysplasia for trochleoplasty simulation and trainee education.

That which is unseen: 3D printing for pediatric cerebrovascular education.

INTRODUCTION: Pediatric cerebrovascular lesions are very rare and include aneurysms, arteriovenous malformations (AVM), and vein of Galen malformations (VOGM). OBJECTIVE: To describe and disseminate a validated, reproducible set of 3D models for optimization of neurosurgical training with respect to pediatric cerebrovascular diseases METHODS: All pediatric cerebrovascular lesions treated at our institution with adequate imaging studies during the study period 2015-2020 were reviewed by the study team. Three major diagnostic groups were identified: aneurysm, AVM, and VOGM. For each group, a case deemed highly illustrative of the core diagnostic and therapeutic principles was selected by the lead and senior investigators for printing (CSG/JM). Files for model reproduction and free distribution were prepared for inclusion as Supplemental Materials. RESULTS: Representative cases included a 7-month-old female with a giant left MCA aneurysm; a 3-day-old male with a large, complex, high-flow, choroidal-type VOGM, supplied from bilateral thalamic, choroidal, and pericallosal perforators, with drainage into a large prosencephalic vein; and a 7-year-old male with a left frontal AVM with one feeding arterial vessel from the anterior cerebral artery and one single draining vein into the superior sagittal sinus CONCLUSION: Pediatric cerebrovascular lesions are representative of rare but important neurosurgical diseases that require creative approaches for training optimization. As these lesions are quite rare, 3D-printed models and open source educational materials may provide a meaningful avenue for impactful clinical teaching with respect to a wide swath of uncommon or unusual neurosurgical diseases.

The Role of 3D Printing in Treatment Planning of Spine and Sacral Tumors.

Three-dimensional (3D) printing technology has proven to have many advantages in spine and sacrum surgery. 3D printing allows the manufacturing of life-size patient-specific anatomic and pathologic models to improve preoperative understanding of patient anatomy and pathology. Additionally, virtual surgical planning using medical computer-aided design software has enabled surgeons to create patient-specific surgical plans and simulate procedures in a virtual environment. This has resulted in reduced operative times, decreased complications, and improved patient outcomes. Combined with new surgical techniques, 3D-printed custom medical devices and instruments using titanium and biocompatible resins and polyamides have allowed innovative reconstructions.

Incremental diagnostic yield and clinical outcomes of lateral decubitus CT myelogram immediately following negative lateral decubitus digital subtraction myelogram.

INTRODUCTION: Spontaneous intracranial hypotension (SIH) caused by a spinal cerebrospinal fluid (CSF) leak classically presents with orthostatic headache. Digital subtraction myelography (DSM) has a well-established diagnostic yield in the absence of extradural spinal collection. At our institution, DSM is followed by lateral decubitus CT myelogram (LDCTM) in the same decubitus position to increase diagnostic yield of the combined study. We evaluated the incremental diagnostic yield of LDCTM following negative DSM and reviewed patient outcomes. METHODS: Retrospective review of consecutive DSMs with subsequent LDCTM from April 2019 to March 2021 was performed. Combined reports were reviewed, and studies with positive DSMs were excluded. Of the exams with negative DSM, only studies with LDCTM reports identifying potential leak site were included. Interventions and follow-up clinical notes were reviewed to assess symptoms improvement following treatment. RESULTS: Of the 83 patients with negative DSMs, 11 (13.2%) had positive leak findings on LDCTMs, and 21 (25.3%) were equivocal. Of 11 positive LDCTMs, 6 leaks were nerve sheath tears (NSTs) and 5 were CSF-venous fistulas (CVFs). 10/11 (90.9%) had intervention and follow-up, with 9/10 (90%) having positive clinical outcome. Of the 21 equivocal LDCTM patients (19 CVFs and 2 NSTs), 15 (71.4%) had interventions and follow-up, with 3/15 (20.0%) with positive clinical outcomes. CONCLUSION: LDCTM following negative DSM has an incremental diagnostic yield up to 38.6%, with up to 14.5% of positive patient outcomes following treatment. LDCTM should be considered after DSM to maximize diagnostic yield of the combined exam.

A Radiologist's Guide to the 2021 WHO Central Nervous System Tumor Classification: Part 2-Newly Described and Revised Tumor Types.

The fifth edition of the World Health Organization classification of tumors of the central nervous system (CNS), published in 2021, introduces major shifts in the classification of brain and spine tumors. These changes were necessitated by rapidly increasing knowledge of CNS tumor biology and therapies, much of which is based on molecular methods in tumor diagnosis. The growing complexity of CNS tumor genetics has required reorganization of tumor groups and acknowledgment of new tumor entities. For radiologists interpreting neuroimaging studies, proficiency with these updates is critical in providing excellent patient care. This review will focus on new or revised CNS tumor types and subtypes, beyond infiltrating glioma (described in part 1 of this series), with an emphasis on imaging features.

Trends in early gestation stillbirths and neonatal deaths in New South Wales, Australia 2002-2019.

BACKGROUND: Little research has focused on understanding trends in early gestation (20-27 weeks) stillbirths and neonatal deaths. AIMS: To examine trends in early gestation stillbirths and neonatal deaths in New South Wales (NSW), Australia. MATERIALS AND METHODS: Population-based cohort study of all births ≥20 weeks gestation among female NSW residents during 2002 to 2019, induced pregnancy terminations excluded. Stillbirth rates by gestational age and birth year were calculated per 1000 fetuses-at-risk (FAR). Neonatal death rates by gestational age and birth year were calculated per 1000 live births. Linear regression was used to examine trends in stillbirth and neonatal death rates among all, singleton and twin births. RESULTS: Declining trends in early gestation stillbirth and neonatal death rates were found. Stillbirth rates decreased from 1.9 and 0.9/1000 FAR in 2002 to 1.6 and 0.7 in 2019 for 20-23 and 24-27 week groups, respectively. Neonatal rates decreased from 940 and 315/1000 live births in 2002 to 925 and 189 in 2019 for the 20-23 and 24-27 week groups, respectively. Among singleton births, declining trends in stillbirth and neonatal death rates across all age groups were observed, except for 37-38 week stillbirths. No trends in twin stillbirth rates were found across gestational age groups, although a decreasing trend was observed for 20-23 week twin neonatal deaths. CONCLUSIONS: Trends in early gestation stillbirth and neonatal deaths have declined in recent decades in NSW but further efforts are needed to reduce both early and late gestation stillbirth rates among twin births.

Development and validation of a unifying pre-treatment decision tool for intracranial and extracranial metastasis-directed radiotherapy.

Background: Though metastasis-directed therapy (MDT) has the potential to improve overall survival (OS), appropriate patient selection remains challenging. We aimed to develop a model predictive of OS to refine patient selection for clinical trials and MDT. Patients and methods: We assembled a multi-institutional cohort of patients treated with MDT (stereotactic body radiation therapy, radiosurgery, and whole brain radiation therapy). Candidate variables for recursive partitioning analysis were selected per prior studies: ECOG performance status, time from primary diagnosis, number of additional non-target organ systems involved (NOS), and intracranial metastases. Results: A database of 1,362 patients was assembled with 424 intracranial, 352 lung, and 607 spinal treatments (n=1,383). Treatments were split into training (TC) (70%, n=968) and internal validation (IVC) (30%, n=415) cohorts. The TC had median ECOG of 0 (interquartile range [IQR]: 0-1), NOS of 1 (IQR: 0-1), and OS of 18 months (IQR: 7-35). The resulting model components and weights were: ECOG = 0, 1, and > 1 (0, 1, and 2); 0, 1, and > 1 NOS (0, 1, and 2); and intracranial target (2), with lower scores indicating more favorable OS. The model demonstrated high concordance in the TC (0.72) and IVC (0.72). The score also demonstrated high concordance for each target site (spine, brain, and lung). Conclusion: This pre-treatment decision tool represents a unifying model for both intracranial and extracranial disease and identifies patients with the longest survival after MDT who may benefit most from aggressive local therapy. Carefully selected patients may benefit from MDT even in the presence of intracranial disease, and this model may help guide patient selection for MDT.

Craniomaxillofacial Trauma: The Past, Present and the Future.

Reconstruction of facial trauma has seen a significant evolutionary leap in the last 100 years. The current surgical management of facial fractures was made possible by the efforts and creativity of pioneer surgeons, advances in anatomic understanding, and the continued development of biomaterials and imaging technologies. Virtual surgical planning (VSP) and 3-dimensional printing (3DP) are being incorporated into the management of acute facial trauma. The integration of this technology at the point of care is rapidly expanding globally. This article reviews the history of the management of craniomaxillofacial trauma, current practices, and future directions. The use of VSP and 3DP in facial trauma care is highlighted with a description of EPPOCRATIS, a rapid point-of-care process incorporating VSP and 3DP at the trauma center.

Thermoprotection of Neural Structures During Musculoskeletal Ablation.

Percutaneous thermal ablation is widely used for local control and palliation of a variety of lesions throughout the musculoskeletal system. In this setting, safe ablation is predicated on the avoidance of unintentional injury to vulnerable neural structures that are often in proximity to ablation targets. This article highlights key periprocedural considerations in musculoskeletal ablation and reviews the array of active and passive thermoprotective measures that are critical to safe and successful treatment.

Foundations and guidelines for high-quality three-dimensional models using photogrammetry: A technical note on the future of neuroanatomy education.

Hands-on dissections using cadaveric tissues for neuroanatomical education are not easily available in many educational institutions due to financial, safety, and ethical factors. Supplementary pedagogical tools, for instance, 3D models of anatomical specimens acquired with photogrammetry are an efficient alternative to democratize the 3D anatomical data. The aim of this study was to describe a technical guideline for acquiring realistic 3D anatomic models with photogrammetry and to improve the teaching and learning process in neuroanatomy. Seven specimens with different sizes, cadaveric tissues, and textures were used to demonstrate the step-by-step instructions for specimen preparation, photogrammetry setup, post-processing, and display of the 3D model. The photogrammetry scanning consists of three cameras arranged vertically facing the specimen to be scanned. In order to optimize the scanning process and the acquisition of optimal images, high-quality 3D models require complex and challenging adjustments in the positioning of the specimens within the scanner, as well as adjustments of the turntable, custom specimen holders, cameras, lighting, computer hardware, and its software. MeshLab® software was used for editing the 3D model before exporting it to MedReality® (Thyng, Chicago, IL) and SketchFab® (Epic, Cary, NC) platforms. Both allow manipulation of the models using various angles and magnifications and are easily accessed using mobile, immersive, and personal computer devices free of charge for viewers. Photogrammetry scans offer a 360° view of the 3D models ubiquitously accessible on any device independent of operating system and should be considered as a tool to optimize and democratize the teaching of neuroanatomy.