3D preoperative planning in the ER with OsiriX®: when there is no time for neuronavigation

The use of advanced technology for preoperative planning in cranial surgery - A survey by the EANS Young Neurosurgeons Committee

Introduction

Technological advancements provided several preoperative tools allowing for precise preoperative planning in cranial neurosurgery, aiming to increase the efficacy and safety of surgery. However, little data are available regarding if and how young neurosurgeons are trained in using such technologies, how often they use them in clinical practice, and how valuable they consider these technologies.

Research question

How frequently these technologies are used during training and clinical practice as well as to how their perceived value can be qualitatively assessed.

Materials and methods

The Young Neurosurgeons' Committee (YNC) of the European Association of Neurosurgical Societies (EANS) distributed a 14-items survey among young neurosurgeons between June 1st and August 31st, 2022.

Results

A total of 441 responses were collected. Most responders (42.34%) received "formal" training during their residency. Planning techniques were used mainly in neuro-oncology (90.86%), and 3D visualization of patients' DICOM dataset using open-source software was the most frequently used (>20 times/month, 20.34% of responders). Software for 3D visualization of patients' DICOM dataset was the most valuable technology, especially for planning surgical approach (42.03%). Conversely, simulation based on augmented/mixed/virtual reality was considered the less valuable tool, being rated below sufficiency by 39.7% of responders.

Discussion and conclusion

Training for using preoperative planning technologies in cranial neurosurgery is provided by neurosurgical residency programs. Software for 3D visualization of DICOM datasets is the most valuable and used tool, especially in neuro-oncology. Interestingly, simulation tools based on augmented/virtual/mixed reality are considered less valuable and, therefore, less used than other technologies.

Virtual preoperative planning and 3D tumoral reconstruction with Horos open-source software

Background

Presurgical three-dimensional (3D) reconstructions allow spatial localization of cerebral lesions and their relationship with adjacent anatomical structures for optimal surgical resolution. The purpose of the present article is to present a method of virtual preoperative planning aiming to enhance 3D comprehension of neurosurgical pathologies using free DICOM image viewers.

Case Description

We describe the virtual presurgical planning of a 61-year-old female presenting a cerebral tumor. 3D reconstructions were created with the "Horos^®" Digital Imaging and Communications in Medicine viewer, utilizing images obtained from contrast-enhanced brain magnetic resonance imaging and computed tomography. The tumor and adjacent relevant structures were identified and delimited. A sequential virtual simulation of the surgical stages for the approach was performed with the identification of local gyral and vascular patterns of the cerebral surface for posterior intraoperative recognition. Through virtual simulation, an optimal approach was gained. Accurate localization and complete removal of the lesion were achieved during the surgical procedure. Virtual presurgical planning with open-source software can be utilized for supratentorial pathologies in both urgent and elective cases. Virtual recognition of vascular and cerebral gyral patterns is helpful reference points for intraoperative localization of lesions lacking cortical expression, allowing less invasive corticotomies.

Conclusion

Digital manipulation of cerebral structures can increase anatomical comprehension of neurosurgical lesions to be treated. 3D interpretation of neurosurgical pathologies and adjacent anatomical structures is essential for developing an effective and safe surgical approach. The described technique is a feasible and accessible option for presurgical planning.

Extended reality platform for minimally invasive endoscopic evacuation of deep-seated intracerebral hemorrhage: illustrative case

BACKGROUND

Extended reality (XR) offers an interactive visualization platform that combines virtual reality (VR) for preoperative planning and augmented reality (AR) for intraoperative navigation overlay.

OBSERVATIONS

XR was used for treating a case of spontaneous intracerebral hemorrhage (ICH) requiring neurosurgical intervention to decompress a hemorrhage in the subcortical area involving the thalamus that was starting to compress the midbrain. The selected surgical technique was an endoscopic aspiration combined with neurosurgical navigation. Because of the deep-seated location of this ICH, a patient-specific 360XR model rendered using Surgical Theater was used for preoperative planning and intraoperative navigation to allow for enhanced visualization and understanding of the pathology and surrounding anatomy.

LESSONS

The XR platform enabled visualization of critical structures near the ICH by extracting and highlighting the white matter tracts from magnetic resonance imaging (MRI) with tractography, which improved preoperative planning beyond using state-of-the-art neuronavigation techniques alone. Once the trajectory was set, the model was integrated with the neuronavigation system, and the planned approach was referenced throughout the procedure to evacuate the clots without further injuring the brain. The patient tolerated the procedure well and was doing well 11 months after his spontaneous ICH.

Three-Dimensional Reconstruction of the Sphenoid Sinus Anatomy for Presurgical Planning with Free OSIRIX Software

Background A preoperative three-dimensional (3D) surgical field understanding remains a key factor to achieve safer endonasal transsphenoidal endoscopic approaches (ETSE). The aim of this article is to describe how we can get a reliable 3D sphenoidal anatomical reconstruction for surgical planning by using a user-friendly, accurate, and free image software.

Methods Free computer software (OSIRIX Medical Imaging Software) was used to create in a personal computer a three-dimensional (3D) reconstruction of the sphenoid sinus (SS) based on head computed tomography angiographies (CTAs) from a series of 67 patients who were operated for sellar tumors during a 4-year period (March 2016 to March 2020). The aim of the 3D reconstruction with OSIRIX was to reveal preoperatively the most important intrasphenoidal structures seen from the endonasal point of view.

Results The intraoperative visible sphenoidal structures were previously recognized in the virtual 3D reconstructed image with 100% of specificity (SP) and positive predictive value. The OSIRIX view by using region of interest points allowed us to see preoperatively the internal carotid artery parasellar course even in those cases in which it was hidden by bone or tumor. Moreover, the 3D reconstruction was able to provide a clear differentiation between the tumor and the pituitary gland when both structures were in contact with the sellar floor.

Conclusion Our experience with the OSIRIX software from CTA as preoperative planning for endonasal pituitary surgery was valuable, because it gave us access in simple way to a free and reliable 3D image of the SS.

Real-time augmented reality application in presurgical planning and lesion scalp localization by a smartphone

OBJECTIVE

A smartphone augmented reality (AR) application (app) was explored for clinical use in presurgical planning and lesion scalp localization.

METHODS

We programmed an AR App on a smartphone. The accuracy of the AR app was tested on a 3D-printed head model, using the Euclidean distance of displacement of virtual objects. For clinical validation, 14 patients with brain tumors were included in the study. Preoperative MRI images were used to generate 3D models for AR contents. The 3D models were then transferred to the smartphone AR app. Tumor scalp localization was marked, and a surgical corridor was planned on the patient's head by viewing AR images on the smartphone screen. Standard neuronavigation was applied to evaluate the accuracy of the smartphone. Max-margin distance (MMD) and area overlap ratio (AOR) were measured to quantitatively validate the clinical accuracy of the smartphone AR technique.

RESULTS

In model validation, the total mean Euclidean distance of virtual object displacement using the smartphone AR app was 4.7 ± 2.3 mm. In clinical validation, the mean duration of AR app usage was 168.5 ± 73.9 s. The total mean MMD was 6.7 ± 3.7 mm, and total mean AOR was 79%.

CONCLUSIONS

The smartphone AR app provides a new way of experience to observe intracranial anatomy in situ, and it makes surgical planning more intuitive and efficient. Localization accuracy is satisfactory with lesions larger than 15 mm.

Improvements in planning lacrimal surgery using DICOM Horos® viewer 3D images

INTRODUCTION AND OBJECTIVE

The individual anatomic variation of the course of the lacrimal duct and surrounding structures requires the thorough knowledge of its three-dimensional configuration in order to perform the surgery in the safest and most efficient way. The aim of this study was to consider virtual surgical planning in order to improve dacryocystorhinostomies.

METHODS

Horos® was used as a viewer and manager of DICOM-format images for multiplanar, three-dimensional (3D) reconstruction when planning 148 first-time lacrimal operations and 26 reoperations by laser endonasal and endocanalicular DCRs.

RESULTS

The 3D images of the CT dacryocystography were much better identified than the 2D ones, Horos® showing a statistically significant correlation (P < .0001). Over 98.27% of the images match the programme reconstruction. Less than 1.73% of them showed some discordance due to study distortion. These cases were related to trauma. The intraopearative location of the lacrimal system was very accurate, avoiding complications.

CONCLUSIONS

Viewing and studying 3D images, Horos® is a very useful tool for diagnosis and preoperative planning. It is very helpful in complex conditions by marking surgical references, locating the lacrimal sac and controlling the post-operative permeability of the lacrimal system. The information loss produced by the image selection is also avoided. Another great advantage is that the programme is free.

Improvements in planning lacrimal surgery using DICOM Horos® viewer 3D images

INTRODUCTION AND OBJECTIVE

The individual anatomic variation of the course of the lacrimal duct and surrounding structures requires the thorough knowledge of its three-dimensional configuration in order to perform the surgery in the safest and most efficient way. The aim of this study was to consider virtual surgical planning in order to improve dacryocystorhinostomies.

METHODS

Horos® was used as a viewer and manager of DICOM-format images for multiplanar, three-dimensional (3D) reconstruction when planning 148 first-time lacrimal operations and 26 reoperations by laser endonasal and endocanalicular DCRs.

RESULTS

The 3D images of the CT dacryocystography were much better identified than the 2D ones, Horos® showing a statistically significant correlation (P<.0001). Over 98.27% of the images match the programme reconstruction. Less than 1.73% of them showed some discordance due to study distortion. These cases were related to trauma. The intraopearative location of the lacrimal system was very accurate, avoiding complications.

CONCLUSIONS

Viewing and studying 3D images, Horos® is a very useful tool for diagnosis and preoperative planning. It is very helpful in complex conditions by marking surgical references, locating the lacrimal sac and controlling the post-operative permeability of the lacrimal system. The information loss produced by the image selection is also avoided. Another great advantage is that the programme is free.

Ultra-Early Venous Thromboembolism (VTE) Prophylaxis in Spontaneous Intracerebral Hemorrhage (sICH)

OBJECTIVE

To determine if ultra-early (<24 h) venous thromboembolism (VTE) prophylaxis was associated with hematoma growth in spontaneous intracerebral hemorrhage (ICH).

BACKGROUND

Patients with ICH have a high risk of VTE. Pharmacological prophylaxis such as unfractionated heparin (UFH) have been demonstrated to reduce VTE. However, published datasets exclude patients with recent ICH out of concern for hematoma enlargement. American Heart/Stroke Association guidelines recommend UFH 1-4 days after hematoma stabilization while the European Stroke Organization has no recommendations on when to begin UFH. Our institutional practice is to obtain stability CT scans at 6 to 24 h and to begin UFH following documented clinical and radiologic stability. We examined the impact of this practice on hematoma expansion.

METHODS

We performed a retrospective cohort analysis of consecutive ICH patients treated at a single tertiary academic referral center in the US. Demographic and clinical characteristics were abstracted. ICH volume was measured via 3D volumetrics for a CT head done on admission, follow-up stability, and prior to discharge. The primary outcome was analyzed as ≥3 mL hematoma enlargement. Secondary outcomes include hematoma expansion of ≥6mL and ≥ 33%, length of stay (LOS), discharge disposition and mortality.

RESULTS

A total of 163 ICH patients were analyzed. There were 58 (35.6%) patients in the ultra-early UFH group and UFH was initiated on average at 13.8 h from initial scan. There were 105 (64.6%) patients in the standard group who initiated UFH at an average of 46.6 h. The primary outcome of hematoma enlargement ≥3 mL was observed in 2/58(3.4%) patients with ultra-early initiation of UFH and in 7/105(6.7%) in the standard group (p=0.49). Secondary outcomes were not significant including hematoma expansion in the ultra-early group ≥ 6 mL 3/58 (5.2%) and ≥33% 7/58 (12.1%) (p=0.91, 0.61, respectively) as well as mortality or LOS.

CONCLUSION

Venous thromboembolism prophylaxis started ultra-early (≤24 h) after ICH was not associated with hematoma expansion.

CXCR7, CXCR4, and Their Ligand Expression Profile in Traumatic Brain Injury

OBJECTIVE

Traumatic brain injury (TBI) is a health problem worldwide, and therapeutic strategies to enhance brain tissue repair to lessen neurologic sequels are imperative. We aimed to analyze the impact of the inflammatory process in TBI through CXCR4 and CXCR7 chemokine receptors and their ligands' CXCL11 and CXCL12 expression profile in search for potential new druggable targets.

METHODS

Twelve pericontusional tissues from severe TBI patients submitted to surgical treatment, and 20 control brain tissues from normal autopsy were analyzed for expression profile by real-time quantitative-polymerase chain reaction. CXCR7 and CXCR4 protein expressions were analyzed by immunohistochemistry. The findings were correlated with the clinical evolution.

RESULTS

Increased gene expression of both receptors and their ligands was observed in TBI compared with controls, presenting high sensitivity and specificity to differentiate TBI from normal control (area under the curve ranging from 0.85 to 0.98, P < 0.001). In particular, CXCR7 expression highly correlated with CXCR4 and both ligands' expressions in TBI. Higher immunoreactions for CXCR7 and CXCR4 were identified in neurons and endothelial cells of TBI samples compared with controls. The patients presenting upregulated chemokine expression levels showed a trend toward favorable clinical evolution at up to 6 months of follow-up.

CONCLUSIONS

The neuroprotective trend of CXCR4, CXCR7, CXCL11, and CXCL12 in TBI observed in this initial analysis warrants further studies with more patients, analyzing the involved signaling pathways for the development of new therapeutic strategies for TBI.

The Use of Osirix for Surgical Planning Using Cranial Measures and Region of Interest Tools: Technical Note

Background:

During the surgery for intrinsic brain lesions, it is important to plan the proper site of the craniotomy and to identify the relations with the gyri and superficial veins. This might be a challenge, especially in small subcortical lesions and when there is a distortion of the cortical anatomy.

Materials and Methods:

Using the free computer software Osirix, we have created a 3-dimensional reconstruction of the head and cerebral showing the gyri and superficial veins. With the aid of some tools, it is possible to create a colored image of the lesion and also to calculate the distance between the areas of interest and some easily identifiable structure, making it easier to plan the site of the craniotomy identify the topography of the lesion.

Results:

The reconstructions were compared to the intraoperative view. We found this technique to be useful to help identify the gyri and cortical veins and use them to find the lesions. The use of a region of interest to show better the lesion under the cortical surface and in the three-dimensional reconstruction of the head was also helpful.

Conclusions:

This is a low-cost and easy technique that can be quickly learned and performed before every surgery. It helps the surgeon to plan a safe craniotomy and lesionectomy.

Is patient-specific pre-operative preparation feasible in a clinical environment? A systematic review and meta-analysis

Technical difficulty of an operation is associated with patient and disease characteristics, indicating the necessity for surgeons to exercise patient-specific preparation. Such methods have been shown to be effective in the simulation suite, however, application in a real clinical environment has been sporadic. This systematic review attempts to answer if patient-specific preparation in challenging surgical procedures is feasible. A systematic review of OvidMedline, Embase and all Evidence Based Medicine review databases, was conducted in search of studies who described surgical rehearsals in all specialties. Following the application of defined inclusion and exclusion criteria relevant data were extracted and summarised. Descriptive synthesis was performed for all included studies and meta-analysis of data was applied when possible. Of fourty-nine studies included, thirty-seven were case-series, ten were non-randomised comparative trials and two randomised controlled trials. Accuracy of applied methods ranged from 66.7 to 100% and a good outcome was seen in 60-100% of operations. Meta-analysis of studies comparing rehearsals to real procedures (same patients) showed that simulated procedures were significantly faster than real ones (SMD = -1.56 [-2.19, -0.93] p < 0.00001) but were similar in other outcomes (fluoroscopy time: SMD = -0.1 [-0.63, 0.42] p = 0.7, fluoroscopy volume: SMD = -0.43[-0.97, 0.11], p = 0.12). Meta-analysis of studies comparing pre-operative rehearsals to standard treatment (two distinct groups of patients), demonstrated that real procedures were performed quicker if pre-operative rehearsal took place (SMD = -0.47 [-0.79, -0.16], P  = 0.003) but the immediate clinical outcome was similar for practiced and not practiced operations (SMD =0.03[-0.23, 0.29], p = 0.82). Current evidence suggests that patient-specific pre-operative preparation is feasible and safe and decreases operational time.

Stereoscopic Images from Computed Tomography Angiograms

OBJECTIVE

To present an adaptation of the anaglyph photography technique to be used with radiological images from computed tomography angiograms, enabling stereoscopic visualization of a patient's individual abnormal vascular anatomy for teaching, case discussion, or surgical planning purposes.

METHODS

Traditional anaglyph procedures with actual objects yield 2 independent photographs, simulating the image perceived by each eye. Production of anaglyphs from angiograms involve 3 basic procedures: volume rendering, image capture, and image fusion. Volume renderings were reconstructed using a free, open-source DICOM (Digital Imaging and Communications in Medicine) reader. Subsequently, the virtual object was positioned to mimic the operator's angle of view, and different perspectives of the reconstructed volume could be obtained through exclusively horizontal rotation. The 2 images were then fused after their color composition was modified so that each eye would perceive only 1 image when using anaglyph glasses.

RESULTS

Forty-three angiograms were reviewed for the purpose of this study and a total of 6 examinations were selected for illustration of the technique. Stereoscopic display was possible for all of them and in the 3 types of support tested: computer monitor, tablet, and smartphone screens.

CONCLUSIONS

Anaglyph display of computed tomography angiograms is an effective and low-cost alternative for the stereoscopic visualization of a patient's individual intracranial vascular anatomy.

Smartphone-assisted minimally invasive neurosurgery

OBJECTIVE

Advances in video and fiber optics since the 1990s have led to the development of several commercially available high-definition neuroendoscopes. This technological improvement, however, has been surpassed by the smartphone revolution. With the increasing integration of smartphone technology into medical care, the introduction of these high-quality computerized communication devices with built-in digital cameras offers new possibilities in neuroendoscopy. The aim of this study was to investigate the usefulness of smartphone-endoscope integration in performing different types of minimally invasive neurosurgery.

METHODS

The authors present a new surgical tool that integrates a smartphone with an endoscope by use of a specially designed adapter, thus eliminating the need for the video system customarily used for endoscopy. The authors used this novel combined system to perform minimally invasive surgery on patients with various neuropathological disorders, including cavernomas, cerebral aneurysms, hydrocephalus, subdural hematomas, contusional hematomas, and spontaneous intracerebral hematomas.

RESULTS

The new endoscopic system featuring smartphone-endoscope integration was used by the authors in the minimally invasive surgical treatment of 42 patients. All procedures were successfully performed, and no complications related to the use of the new method were observed. The quality of the images obtained with the smartphone was high enough to provide adequate information to the neurosurgeons, as smartphone cameras can record images in high definition or 4K resolution. Moreover, because the smartphone screen moves along with the endoscope, surgical mobility was enhanced with the use of this method, facilitating more intuitive use. In fact, this increased mobility was identified as the greatest benefit of the use of the smartphone-endoscope system compared with the use of the neuroendoscope with the standard video set.

CONCLUSIONS

Minimally invasive approaches are the new frontier in neurosurgery, and technological innovation and integration are crucial to ongoing progress in the application of these techniques. The use of smartphones with endoscopes is a safe and efficient new method of performing endoscope-assisted neurosurgery that may increase surgeon mobility and reduce equipment costs.

Surgical Performance in Minimally Invasive Surgery Plus Recombinant Tissue Plasminogen Activator for Intracerebral Hemorrhage Evacuation Phase III Clinical Trial

BACKGROUND

Minimally invasive thrombolytic evacuation of intracerebral hematoma is being investigated in the ongoing phase III clinical trial of Minimally Invasive Surgery plus recombinant Tissue plasminogen activator for Intracerebral hemorrhage Evacuation (MISTIE III).

OBJECTIVE

To assess the accuracy of catheter placement and efficacy of hematoma evacuation in relation to surgical approach and surgeon experience.

METHODS

We performed a trial midpoint interim assessment of 123 cases that underwent the surgical procedure. Accuracy of catheter placement was prospectively assessed by the trial Surgical Center based on prearticulated criteria. Hematoma evacuation efficacy was evaluated based on absolute volume reduction, percentage hematoma evacuation, and reaching the target end-of-treatment volume of <15 mL. One of 3 surgical trajectories was used: anterior (A), posterior (B), and lobar (C). Surgeons were classified based on experience with the MISTIE procedure as prequalified, qualified with probation, and fully qualified.

RESULTS

The average hematoma volume was 49.7 mL (range 20.0-124), and the mean evacuation rate was 71% (range 18.4%-99.8%). First placed catheters were 58% in good position, 28% suboptimal (but suitable to dose), and 14% poor (requiring repositioning). Posterior trajectory (B) was associated with significantly higher rates of poor placement (35%, P = .01). There was no significant difference in catheter placement accuracy among surgeons of varying experience. Hematoma evacuation efficacy was not significantly different among the 3 surgical approaches or different surgeons' experience.

CONCLUSION

Ongoing surgical education and quality monitoring in MISTIE III have resulted in consistent rates of hematoma evacuation despite technical challenges with the surgical approaches and among surgeons of varying experience.

OsiriX software as a preoperative planning tool in cranial neurosurgery: A step-by-step guide for neurosurgical residents

Background:

OsiriX (Pixmeo, Switzerland) is an open-source Digital Imaging and Communications in Medicine (DICOM) viewer that is gaining more and more attention in the neurosurgical community because of its user-friendly interface, powerful three-dimensional (3D) volumetric rendering capabilities, and various options for data integration. This paper presents in detail the use of OsiriX software as a preoperative planning tool in cranial neurosurgery.

Methods:

In January 2013, OsiriX software was introduced into our clinical practice as a preoperative planning tool. Its capabilities are being evaluated on an ongoing basis in routine elective cranial cases.

Results:

The program has proven to be highly effective at volumetrically representing data from radiological examinations in 3D. Among its benefits in preoperative planning are simulating the position and exact location of the lesion in 3D, tailoring the skin incision and craniotomy bone flap, enhancing the representation of normal and pathological anatomy, and aiding in planning the reconstruction of the affected area.

Conclusion:

OsiriX is a useful tool for preoperative planning and visualization in neurosurgery. The software greatly facilitates the surgeon's understanding of the relationship between normal and pathological anatomy and can be used as a teaching tool.

Usefulness of Computed Tomography Image Processing by OsiriX Software in Detecting Wooden and Bamboo Foreign Bodies

Objective

The aim of this study was to evaluate the usefulness of reconstructed computed tomography (CT) images using OsiriX software in detecting wooden and bamboo foreign bodies.

Methods

Four sizes of wet and dry wooden and bamboo foreign bodies were selected to be analyzed. Those in the air and in the head of edible swine were scanned with a multidetector row CT scanner. The images were evaluated with OsiriX software in the bone and the abdomen window setting as unprocessed images. Three-dimensional rendered images assigned colors and opacity by a 16-bit color look-up table (CLUT) editor in OsiriX software were evaluated as processed images.

Results

In the unprocessed images, dry and wet foreign bodies in the air were not detected except a part of wet wooden foreign bodies, and all the dry and wet foreign bodies in the swine's head mimicked air with linear shapes. In the processed images, all the dry and wet foreign bodies in the air were detected clearly, and all the wooden and some of the bamboo foreign bodies in the swine's head were detected clearly.

Conclusions

CT images processed using OsiriX software, especially with a CLUT editor, were useful in detecting wooden and bamboo foreign bodies.

Technical nuances of subtemporal approach for the treatment of basilar tip aneurysm

Background:

Basilar tip aneurysms are one of the most complex vascular lesions to treat surgically because of their location, depth of the approach, and close proximity of vital neurovascular structures such as the mesencephalon, cranial nerves, perforating arteries to the thalamus. There are different surgical approaches utilized to reach basilar tip aneurysms, namely, pterional, pretemporal, orbitozygomatic, subtemporal, and anterior petrosectomy. Each of them has its advantages and limitations.

Methods:

In this paper, we present our personal experience with the use of subtemporal approach. The technique is described in detail including its nuances and potential pitfalls.

Results:

The subtemporal approach is indicated for basilar tip aneurysms located at the level of the floor of the sella turcica to 1 cm above the dorsum sellae.

Conclusion:

Subtemporal approach offers good surgical corridor for the management of these complex vascular lesions.

A Low-Cost iPhone-Assisted Augmented Reality Solution for the Localization of Intracranial Lesions

Background

Precise location of intracranial lesions before surgery is important, but occasionally difficult. Modern navigation systems are very helpful, but expensive. A low-cost solution that could locate brain lesions and their surface projections in augmented reality would be beneficial. We used an iPhone to partially achieve this goal, and evaluated its accuracy and feasibility in a clinical neurosurgery setting.

Methodology/Principal Findings

We located brain lesions in 35 patients, and using an iPhone, we depicted the lesion’s surface projection onto the skin of the head. To assess the accuracy of this method, we pasted computed tomography (CT) markers surrounding the depicted lesion boundaries on the skin onto 15 patients. CT scans were then performed with or without contrast enhancement. The deviations (D) between the CT markers and the actual lesion boundaries were measured. We found that 97.7% of the markers displayed a high accuracy level (D ≤ 5mm). In the remaining 20 patients, we compared our iPhone-based method with a frameless neuronavigation system. Four check points were chosen on the skin surrounding the depicted lesion boundaries, to assess the deviations between the two methods. The integrated offset was calculated according to the deviations at the four check points. We found that for the supratentorial lesions, the medial offset between these two methods was 2.90 mm and the maximum offset was 4.2 mm.

Conclusions/Significance

This low-cost, image-based, iPhone-assisted, augmented reality solution is technically feasible, and helpful for the localization of some intracranial lesions, especially shallow supratentorial intracranial lesions of moderate size.

Speeding up PET/MR for cancer staging of children and young adults

OBJECTIVE

Combining ¹⁸F-FDG PET with whole-body MR for paediatric cancer staging is practically feasible if imaging protocols can be streamlined. We compared ¹⁸F-FDG PET/STIR with accelerated ¹⁸F-FDG PET/FSPGR for whole-body tumour imaging in children and young adults.

METHODS

Thirty-three children and young adults (17.5 ± 5.5 years, range 10-30) with malignant lymphoma or sarcoma underwent a ¹⁸F-FDG PET staging examination, followed by ferumoxytol-enhanced STIR and FSPGR whole-body MR. ¹⁸F-FDG PET scans were fused with MR data and the number and location of tumours on each integrated examination were determined. Histopathology and follow-up imaging served as standard of reference. The agreement of each MR sequence with the reference and whole-body imaging times were compared using Cohen's kappa coefficient and Student's t-test, respectively.

RESULTS

Comparing ¹⁸F-FDG PET/FSPGR to ¹⁸F-FDG PET/STIR, sensitivities were 99.3 % for both, specificities were statistically equivalent, 99.8 versus 99.9 %, and the agreement with the reference based on Cohen's kappa coefficient was also statistically equivalent, 0.989 versus 0.992. However, the total scan-time for accelerated FSPGR of 19.8 ± 5.3 minutes was significantly shorter compared to 29.0 ± 7.6 minutes for STIR (p = 0.001).

CONCLUSION

F-FDG PET/FSPGR demonstrated equivalent sensitivities and specificities for cancer staging compared to ¹⁸F-FDG PET/STIR, but could be acquired with shorter acquisition time.

KEY POINTS

• Breath-hold FSPGR sequences shorten the data acquisition time for whole-body MR and PET/MR. • Ferumoxytol provides long-lasting vascular contrast for whole-body MR and PET/MR. • ¹⁸ F-FDG PET/FSPGR data provided equal sensitivity and specificity for cancer staging compared to ¹⁸ F-FDG PET/STIR.

Endoscopic-assisted removal of traumatic brain hemorrhage: case report and technical note

The endoscopic technique has been described as a minimally invasive method for spontaneous hematoma evacuation, as a safe and effective treatment. Nevertheless, to our knowledge, there is no description of a technical report of traumatic intracerebral hematoma removal using the neuroendoscope. A 47-year-old man was admitted sustaining 13 points in Glasgow coma scale with brain computed tomography (CT) scan showing a temporal contusion. Guided by a 3D reconstructed CT, using the program OsiriX®, the posterior limit of the hematoma was identified. A burr hole was placed at the posterior temporal region, and we used the neuroendoscope to assist the hematoma evacuation. The postoperative tomography showed adequate hematoma removal. He was discharged from hospital 48 h after surgery. Two weeks later, he was conscious and oriented temporally. This endoscopic-assisted technique can provide safe removal of traumatic hematomas of the temporal lobe.

[Neurosurgical planning using osirix software]

Introducción:

La individualidad anatómica es clave para reducir el trauma quirúrgico y obtener un mejor resultado. Actualmente, el avance en las neuroimágenes ha permitido objetivar esa individualidad anatómica, permitiendo planificar la intervención quirúrgica. Con este objetivo, presentamos nuestra experiencia con el software Osirix.

Descripción de la técnica:

Se presentan 3 casos ejemplificadores de 40 realizados. Caso 1: Paciente con meningioma de la convexidad parasagital izquierda en área premotora; Caso 2: Paciente con macroadenoma hipofisario, operada previamente por vía transeptoesfenoidal en otra institución con una resección parcial; Caso 3: Paciente con lesiones en pedúnculo cerebeloso medio bilateral. Se realizó la planificación prequirúrgica con el software OsiriX, fusionando y reconstruyendo en 3D las imágenes de TC e IRM, para analizar relaciones anatómicas, medir distancias, coordenadas y trayectorias, entre otras funciones.

Discusión:

El software OsiriX de acceso libre y gratuito permite al cirujano, mediante la fusión y reconstrucción en 3D de imágenes, analizar la anatomía individual del paciente y planificar de forma rápida, simple, segura y económica cirugías de alta complejidad. En el Caso 1 se pudo analizar las relaciones del tumor con las estructuras adyacentes para minimizar el abordaje. En el Caso 2 permitió comprender la anatomía post-operatoria previa del paciente, para determinar la trayectoria del abordaje transnasal endoscópico y la necesidad de ampliar su exposición, logrando la resección tumoral completa. En el Caso 3 permitió obtener las coordenadas estereotáxicas y trayectoria de una lesión sin representación tomográfica.

Conclusión:

En casos de no contar con costosos sistemas de neuronavegación o estereotáxia el software OsiriX es una alternativa a la hora de planificar la cirugía, con el objetivo de disminuir el trauma y la morbilidad operatoria.