Functional Network Development in Sagittal Craniosynostosis Treated With Whole Vault Cranioplasty.

INTRODUCTION: In this study, the authors seek to clarify the neurological changes before and after whole vault cranioplasty (WVC) in patients born with sagittal craniosynostosis. METHODS: A case control study design was performed that included thirty functional MRI scans, from 25 individual patients. Functional MRI and diffusion tension imaging data were analyzed with BioImageSuite (Yale University, USA). 9 functional brain networks were analyzed, with appropriate correlated functional regions of the brain and utilized for analysis. RESULTS: Comparing functional MRI the infants after WVC versus infants before WVC group, the after WVC group demonstrated an increased connectivity in the left frontoparietal, secondary (V2), and third (V3) visual networks (P < 0.001). The right frontoparietal (RFPN) had decreased connectivity (P < 0.001). There is also a decrease and increase in anisotropy in the cingulum and precuneus despite surgery, respectively (P < 0.05). Adolescents treated with WVC compared to controls, demonstrated an increased connectivity in the salience and decreased connectivity in the RFPN relative to adolescent controls. CONCLUSIONS: Patients born with sagittal craniosynostosis have different connections in infancy in most of the defined cerebral networks compared to controls. After surgery, there are specific connectivity changes that occur in the RFPN, left frontoparietal, V2, and V3 networks, which are areas associated with executive function and emotional control. Changes identified in white matter tract microstructure connections could be influential in changes in functional connectivity. Although, as a child with sagittal craniosynostosis develops, much of the abnormal network connections, seen in infancy preoperatively, corrects to some degree after surgery. However, some aberrancies in the salience and RFPN networks remain potentially affecting executive functioning.

An Investigation of Brain Functional Connectivity by Form of Craniosynostosis.

PURPOSE: Long-term neurocognitive sequelae of nonsyndromic craniosynostosis (NSC) patients are just beginning to be clarified. This study uses functional MRI (fMRI) to determine if there is evidence of altered brain functional connectivity in NSC, and whether these aberrations vary by form of synostosis. METHODS: Twenty adolescent participants with surgically treated NSC (10 sagittal synostosis, 5 right unilateral coronal synostosis [UCS], 5 metopic synostosis [MSO]) were individually matched to controls by age, gender, and handedness. A subgroup of MSO was classified as severe metopic synostosis (SMS) based on the endocranial bifrontal angle. Resting state fMRI was acquired in a 3T Siemens TIM Trio scanner (Erlangen, Germany), and data were motion corrected and then analyzed with BioImage Suite (Yale School of Medicine). Resulting group-level t-maps were cluster corrected with nonparametric permutation tests. A region of interest analysis was performed based on the left Brodmann's Areas 7, 39, and 40. RESULTS: Sagittal synostosis had decreased whole-brain intrinsic connectivity compared to controls in the superior parietal lobules and the angular gyrus (P = 0.071). Unilateral coronal synostosis had decreased intrinsic connectivity throughout the prefrontal cortex (P = 0.031). The MSO cohort did not have significant findings on intrinsic connectivity, but the SMS subgroup had significantly decreased connectivity among multiple subcortical structures. CONCLUSION: Sagittal synostosis had decreased connectivity in regions associated with visuomotor integration and attention, while UCS had decreased connectivity in circuits crucial in executive function and cognition. Finally, severity of metopic synostosis may influence the degree of neurocognitive aberration. This study provides data suggestive of long-term sequelae of NSC that varies by suture type, which may underlie different phenotypes of neurocognitive impairment.

Understanding the Learning Disabilities Linked to Sagittal Craniosynostosis.

OBJECTIVE: The purpose of this study is to investigate further findings that corroborate similarities between corrected sagittal craniosynostosis and attention deficit hyperactivity disorder (ADHD). The aim is to further characterize the neurocognitive deficits seen in adolescents with corrected craniosynostosis by comparing it to established learning deficits such as ADHD. METHODS: A total of 30 functional magnetic resonance imaging (fMRI) of 10 sagittal nonsyndromic craniosynostosis (sNSC), 10 ADHD-combined, and 10 control adolescents were studied. The fMRI scans were analyzed utilizing Statistical Parametric Mapping (University College London, UK) and analyzed with BioImageSuite (Yale University, New Haven, CT). RESULTS: The ADHD has lower connectivity to Brodmann area (BA) 11 (Montreal Neurological Institution [MNI]: -12,26,-21), BA20 (MNI: 62,-24,-25), and BA21 (MNI: 62,-32,-23) compared to sNSC and controls (P < 0.001). The sNSC has a unique visuospatial defect, compared to ADHD, created by decreased connectivity to BA31 (MNI: -3,-68,37), BA7 (MNI: -4,-68,41), BA19 (MNI: 0,-83,31), visual association cortex (MNI: -4,-78,22), and primary visual cortex (MNI: 7,-74,21) (P < 0.001). CONCLUSION: Patients born with sNSC have different neural connections than children born with ADHD. Patients born with sNSC have decreased connections in areas of visual processing and increased connections in areas of attention and auditory processing than patients with ADHD. Therefore, children with sagittal craniosynsotosis may have learning difficulties that, similar, yet different from ADHD.

What is the Functional Difference Between Sagittal With Metopic and Isolated Sagittal Craniosynotosis?

INTRODUCTION: The purpose of this study is to understand the neurological differences between patients born with combined sagittal and metopic craniosynostosis (SMc) and isolated sagittal craniosynostosis (ISc) by studying aberrations in functional brain connectivity and white matter microstructure, before surgery, utilizing functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI). METHODS: The authors collected DTI and resting-state (ie, no sedation and asleep) functional connectivity MRI data in 10 infant patients preoperatively: 5 in the SMc group (4.3 ±â€Š1 months) and 5 in the ISc group (4.8 ±â€Š1.1 months). Resting state fMRI imaging and DTI data were acquired using a 3-T Siemens Trio MRI system (Erlangen, Germany) while the infant patients slept. fMRI data were corrected for movement using SPM, underwent cerebrospinal fluid and white matter signal regression and further analyzed with BioImageSuite. For the DTI data, 3 diffusion runs were averaged, processed utilizing FMRIB Software Library, and analyzed statistically using BioImageSuite. RESULTS: Comparing the SMc versus ISc groups, SMc demonstrated that there was increased connectivity, statistically significant differences, in neural networks between children with sagittal synostosis alone versus those with sagittal with metopic synostosis, in the right BA 31 and BA 23 (corresponding to the posterior cingulate cortex (PCC) (P < 0.001). Analysis of the DTI revealed increased fractional anisotropy (normal maturation of white tracts) in the SMc group in the cingulum compared to the ISc group (P < 0.05). Differences in the functional networks include increased connectivity right frontoparietal network (RFPN) in ISc and increased connectivity in the primary visual network (V1) in SMc (P < 0.001). CONCLUSION: The SMc had increased connectivity as measured by fMR in the PCC, an area associated with attention deficit hyperactivity disorder. The DTI analysis demonstrated an increase in fractional anisotropy of the cingulum in the SMc group, a white matter tract projecting from the cingulate cortex; connections of the limbic (emotional regulation) system are instrumental. In SMc, increase of connectivity in the PCC correlates with an increase in maturation of the cingulum compared to ISc. There is increased connectivity of the RFPN network in the ISc and increased connectivity of the V1 network in the SMc patients. The SMc group has increased connectivity in the PCC, the original seed of the DMN network, and decreased connectivity to the RFPN network. The pattern of increased connectivity in the area of the DMN and decreased connectivity in the RFPN network is similar to the trend when comparing ADHD patients to normal controls. SMc has more similar functional network connectivity to ADHD as compared to ISc.

The Etiology of Neuronal Development in Craniosynostosis: A Working Hypothesis.

Craniosynostosis is one of the most common craniofacial conditions treated by neurologic and plastic surgeons. In addition to disfigurement, children with craniosynostosis experience significant cognitive dysfunction later in life. Surgery is performed in infancy to correct skull deformity; however, the field is at a crossroads regarding the best approach for correction. Since the cause of brain dysfunction in these patients has remained uncertain, the role and type of surgery might have in attenuating the later-observed cognitive deficits through impact on the brain has been unclear. Recently, however, advances in imaging such as event-related potentials, diffusion tensor imaging, and functional MRI, in conjunction with more robust clinical studies, are providing important insight into the potential etiologies of brain dysfunction in syndromic and nonsyndromic craniosynostosis patients. This review aims to outline the cause(s) of such brain dysfunction including the role extrinsic vault constriction might have on brain development and the current evidence for an intrinsic modular developmental error in brain development. Illuminating the cause of brain dysfunction will identify the role of surgery can play in improving observed functional deficits and thus direct optimal primary and adjuvant treatment.

Does an elevated bony ridge along the course of the metopic suture equal metopic synostosis? Implications for management.

Metopic synostosis represents an increasingly prevalent form of nonsyndromic craniosynostosis. Premature fusion of the metopic suture classically results in trigonocephaly, hypotelorism, temporal narrowing, and a pronounced midline forehead ridge. However, as varying degrees of skull deformity exist, there is confusion regarding the appropriate management for an infant with a metopic ridge. We report on a 2-month-old infant with clinical manifestations of metopic synostosis but with a patent metopic suture documented on computed tomography scan. We examine the implications for management related to fusion of the suture, age of the patient, and severity of the head deformity.

Digital Phenotyping, Wearables, and Outcomes.

There is a significant need for robust and objective outcome assessments in spine surgery. Constant monitoring via smartphones and wearable devices has the potential to fill this role by providing an in-depth picture of human well-being, creating an unprecedented amount of objective data to augment clinical decision-making. The metrics obtained from continuous patient monitoring increase the amount and ecological validity of data relevant to spine surgery. This can provide physicians with patient and disease-specific medical information, facilitating personalized patient care.

A range of condylar hypoplasia exists in Treacher Collins syndrome.

PURPOSE: Temporomandibular joint malformation is a complex deformity in Treacher-Collins syndrome (TCS); however, it is not well characterized. This study aimed to better clarify this pathology by volumetrically assessing the mandibular condyle in patients with TCS compared with normal controls and the relative contribution of the condyle to hemimandibular volume. MATERIALS AND METHODS: A retrospective, cross-sectional analysis of pediatric patients with TCS and unaffected controls was performed. The study sample was comprised of Treacher Collins patients. The predictor variable in this study was disease status (TCS diagnosis vs control), and the outcome variable was condylar volume. Demographic information was collected, and 3-dimensional computed tomographic data were analyzed by computerized segmentation (Materialise). Volumes were obtained for TCS condyles and compared with age-matched controls using the Student t test. RESULTS: Three-dimensional computed tomographic scans were identified in 10 patients with TCS (20 sides) and 14 control subjects (28 sides). The TCS group included 4 female and 6 male patients (age, 0.3 to 213 mo; average age, 66.5 mo). The control cohort included 7 female and 7 male subjects (average age, 68.8 mo). Evaluation of the mandibular condyle showed that patients with TCS had a significantly smaller condylar volume than control patients (TCS, 178.28 ± 182.74 mm(3); control, 863.55 ± 367.20 mm(3); P < .001). Additional intragroup analysis showed no significant differences between the left and right condylar volumes in the TCS group (P = .267). In addition, the condyle for patients with TCS represented a smaller proportion of hemimandibular volume compared with controls (1.37% vs 4.19%, respectively; P < .001). CONCLUSIONS: The results of the this study suggest that condylar volumes are significantly smaller in patients with TCS compared with age-matched controls, and the condyle represents a smaller fraction of the total mandibular volume for patients with TCS than in unaffected children. In addition, there is considerable variability of condylar size in patients with TCS. These facts portend treatment decisions because a functional temporomandibular joint is necessary and may need to be reconstructed as a first stage before effective implementation of distraction procedures.

Dolichocephaly without sagittal craniosynostosis.

Premature closure of the sagittal suture is thought to be fundamental to the etiopathology for the disease process called sagittal craniosynostosis. This process traditionally results in a well-known skull malformation termed dolichocephaly. Over recent decades, some authors have questioned the suture as the primary driving force for this pathology. This is a retrospective cases series of 4 patients from 2011 to 2012 who presented to the Yale Craniofacial Clinic for evaluation of dolichocephaly. The 4 children, 3 boys and 1 girl, had physical examinations and cranial indices concerning for sagittal craniosynostosis; however, subsequent computed tomographic imaging revealed sagittal suture patency. This series adds to a growing body of literature, which describes abnormal head shapes not attributable to overt suture pathology.

Lumbar Spinal Canal Segmentation in Cases with Lumbar Stenosis Using Deep-U-Net Ensembles.

BACKGROUND: Narrowing of the lumbar spinal canal, or lumbar stenosis (LS), may cause debilitating radicular pain or muscle weakness. It is the most frequent indication for spinal surgery in the elderly population. Modern diagnosis relies on magnetic resonance imaging and its inherently subjective interpretation. Diagnostic rigor, accuracy, and speed may be improved by automation. In this work, we aimed to determine whether a deep-U-Net ensemble trained to segment spinal canals on a heterogeneous mix of clinical data is comparable to radiologists' segmentation of these canals in patients with LS. METHODS: The deep U-nets were trained on spinal canals segmented by physicians on 100 axial T2 lumbar magnetic resonance imaging selected randomly from our institutional database. Test data included a total of 279 elderly patients with LS that were separate from the training set. RESULTS: Machine-generated segmentations (MA) were qualitatively similar to expert-generated segmentations (ME1, ME2). Machine- and expert-generated segmentations were quantitatively similar, as evidenced by Dice scores (MA vs. ME1: 0.88 ± 0.04, MA vs. ME2: 0.89 ± 0.04), the Hausdorff distance (MA vs. ME1: 11.7 mm ± 13.8, MA vs. ME2: 13.1 mm ± 16.3), and average surface distance (MAvs. ME1: 0.18 mm ± 0.13, MA vs. ME2 0.18 mm ± 0.16) metrics. These metrics are comparable to inter-rater variation (ME1 vs. ME2 Dice scores: 0.94 ± 0.02, the Hausdorff distances: 9.3 mm ± 15.6, average surface distances: 0.08 mm ± 0.09). CONCLUSION: We conclude that machine learning algorithms can segment lumbar spinal canals in LS patients, and automatic delineations are both qualitatively and quantitatively comparable to expert-generated segmentations.

Upper lumbar spine far lateral disc herniations masquerading as peripheral nerve sheath tumors: illustrative cases.

BACKGROUND: Migratory disc herniations can mimic neoplasms clinically and on imaging. Far lateral lumbar disc herniations usually compress the exiting nerve root and can be challenging to distinguish from a nerve sheath tumor due to the proximity of the nerve and characteristics on magnetic resonance imaging (MRI). These lesions can occasionally present in the upper lumbar spine region at the L1-2 and L2-3 levels. OBSERVATIONS: The authors describe 2 extraforaminal lesions in the far lateral space at the L1-2 and L2-3 levels, respectively. On MRI, both lesions tracked along the corresponding exiting nerve roots with avid postcontrast rim enhancement and edema in the adjacent muscle tissue. Thus, they were initially concerning for peripheral nerve sheath tumors. One patient underwent fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) screening and demonstrated moderate FDG uptake on PET-CT scan. In both cases, intraoperative and postoperative pathology revealed fibrocartilage disc fragments. LESSONS: Differential diagnosis for lumbar far lateral lesions that are peripherally enhancing on MRI should include migratory disc herniation, regardless of the level of the disc herniations. Accurate preoperative diagnosis can aid in decision making for management, surgical approach, and resection.

Structural Changes in the Cervicomedullary Junction in Adult Chiari Patients.

OBJECTIVE: To assess volumetric changes in the spinal cord at the cervicomedullary junction, diameter of the cervicomedullary cord, and width of the brainstem following posterior fossa decompression (PFD). METHODS: A retrospective analysis of adult patients with Chiari malformation who underwent PFD was performed. Segmentations were done on clinical quality T2-weighted cervical magnetic resonance images obtained before and after decompression using ITK-SNAP. Volumes of neural tissue within the cervicomedullary junction were evaluated from 10 mm cranial to the medullary beak to the cervical spinal cord at the level of the caudal endplate of the second cervical vertebra. The diameter of the cervicomedullary cord was calculated perpendicular to the spinal cord. The width of the brainstem was measured perpendicular to the clivus at the level of the basion. RESULTS: Twenty adult patients, a mean age of 49.55 years, were included. The cervical cord increased in volume by 13 mm3 to 338 mm3, with an average increase of 155 mm3 (P-value of 0.00002). The diameter of the cervicomedullary cord increased 10.30% 7 mm superior to the beak (P-value of 0.00074), 11.49% at the apex of the beak (P-value of 0.00082), 8.29% 7 mm inferior to the beak (P-value of 0.00075), and the brainstem increased 14.46% perpendicular to the clivus (P-value of 0.00109). The spinal cord at the inferior aspect of the C3 vertebra changed insignificantly (P-value of 0.10580). CONCLUSION: The volume of the cervical cord at the cervical-medullary junction, width of the cervicomedullary cord, and diameter of the brainstem increase following PFD.

Spinal Cord Drift Following Laminoplasty Versus Laminectomy and Fusion for Cervical Spondylotic Myelopathy.

BACKGROUND: Cervical laminoplasty and laminectomy and fusion (LF) are posterior-based surgical techniques for the surgical treatment of cervical spondylotic myelopathy (CSM). Interestingly, the comparative amount of spinal cord drift obtained from these procedures has not been extensively described. The purpose of this study is to compare spinal cord drift between cervical laminoplasty and LF in patients with CSM. METHODS: The laminoplasty group consisted of 22 patients, and the LF group consisted of 44 patients. Preoperative and postoperative alignment was measured using the Cobb angle (C2-C7). Spinal cord position was measured on axial T2-magnetic resonance imaging of the cervical spine preoperatively and postoperatively. Spinal cord drift was quantified by subtracting preoperative values from postoperative values. Functional improvement was assessed using the modified Japanese Orthopaedic Association (mJOA) score. RESULTS: Mean spinal cord drift was higher following LF compared to laminoplasty (2.70 vs 1.71 mm, P < .01). Using logistic regression analysis, there was no correlation between sagittal alignment and spinal cord drift. Both groups showed an improvement in mJOA scores postoperatively compared to their preoperative values (laminoplasty, +2.0, P = .012; LF, +2.4, P < .01). However, there was no difference in mJOA score improvement postoperatively between both groups (P = .482). CONCLUSIONS: This study demonstrates that patients who had LF for CSM achieved more spinal cord drift postoperatively compared to those who had laminoplasty. However, the increased drift did not translate into superior functional outcome as measured by the mJOA score. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Spinal cord drift following LF may differ from laminoplasty in patients undergoing surgery for CSM. This finding should be considered when assessing CSM patients for surgical intervention.

Predictors of Operative Duration and Complications in Single-Level Posterior Interbody Fusions for Degenerative Spondylolisthesis.

BACKGROUND: The goal of this study was to identify predictors of prolonged operative time (OT) in patients receiving posterior/transforaminal lumbar interbody fusion (P/TLIF) and examine the relationship between prolonged OT and perioperative outcomes in this population. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing single-level P/TLIF (Common Procedural Terminology code) between 2012 and 2018. Multivariable linear regression models were constructed to identify factors independently associated with changes in OT and examine the relationship between prolonged OT and perioperative outcomes (overall complications, surgical complications, medical complications, 30-day readmission, 30-day reoperation, and length of stay). All models were adjusted for sociodemographic variables, comorbidities, and procedure-specific variables. RESULTS: Our cohort included 6260 patients. After adjusting for baseline covariates, age between 19 and 39 years increased OT by 15.14 minutes, male sex increased OT by 12.91 minutes, African American race increased OT by 17.82 minutes, other race increased OT by 18.13 minutes, obesity class III increased OT by 27.80 minutes, and the use of navigation increased OT by 10.83 minutes. Our multivariate logistic regression also found that after 2 hours, each additional hour of OT was associated with an increased risk of any complication (3-3.99 hours, odds ratio [OR], 1.68; 4-4.99 hours, OR, 2.33; and >5 hours, OR, 4.65). Incremental increases in OT were also associated with an increased risk of extended length of stay, readmission, and return to the operating room. CONCLUSIONS: The results of this study highlight several factors associated with prolonged OT and underscore its association with poorer perioperative outcomes. These data can be used to risk stratify patients before single-level P/TLIF.

Predicting Spinal Surgery Candidacy From Imaging Data Using Machine Learning.

BACKGROUND: The referral process for consultation with a spine surgeon remains inefficient, given a substantial proportion of referrals to spine surgeons are nonoperative. OBJECTIVE: To develop a machine-learning-based algorithm which accurately identifies patients as candidates for consultation with a spine surgeon, using only magnetic resonance imaging (MRI). METHODS: We trained a deep U-Net machine learning model to delineate spinal canals on axial slices of 100 normal lumbar MRI scans which were previously delineated by expert radiologists and neurosurgeons. We then tested the model against lumbar MRI scans for 140 patients who had undergone lumbar spine MRI at our institution (60 of whom ultimately underwent surgery, and 80 of whom did not). The model generated automated segmentations of the lumbar spinal canals and calculated a maximum degree of spinal stenosis for each patient, which served as our biomarker for surgical pathology warranting expert consultation. RESULTS: The machine learning model correctly predicted surgical candidacy (ie, whether patients ultimately underwent lumbar spinal decompression) with high accuracy (area under the curve = 0.88), using only imaging data from lumbar MRI scans. CONCLUSION: Automated interpretation of lumbar MRI scans was sufficient to correctly determine surgical candidacy in nearly 90% of cases. Given that a significant proportion of referrals placed for spine surgery evaluation fail to meet criteria for surgical intervention, our model could serve as a valuable tool for patient triage and thereby address some of the inefficiencies within the outpatient surgical referral process.

Eigenrank by committee: Von-Neumann entropy based data subset selection and failure prediction for deep learning based medical image segmentation.

Manual delineation of anatomy on existing images is the basis of developing deep learning algorithms for medical image segmentation. However, manual segmentation is tedious. It is also expensive because clinician effort is necessary to ensure correctness of delineation. Consequently most algorithm development is based on a tiny fraction of the vast amount of imaging data collected at a medical center. Thus, selection of a subset of images from hospital databases for manual delineation - so that algorithms trained on such data are accurate and tolerant to variation, becomes an important challenge. We address this challenge using a novel algorithm. The proposed algorithm named 'Eigenrank by Committee' (EBC) first computes the degree of disagreement between segmentations generated by each DL model in a committee. Then, it iteratively adds to the committee, a DL model trained on cases where the disagreement is maximal. The disagreement between segmentations is quantified by the maximum eigenvalue of a Dice coefficient disagreement matrix a measure closely related to the Von Neumann entropy. We use EBC for selecting data subsets for manual labeling from a larger database of spinal canal segmentations as well as intervertebral disk segmentations. U-Nets trained on these subsets are used to generate segmentations on the remaining data. Similar sized data subsets are also randomly sampled from the respective databases, and U-Nets are trained on these random subsets as well. We found that U-Nets trained using data subsets selected by EBC, generate segmentations with higher average Dice coefficients on the rest of the database than U-Nets trained using random sampling (p < 0.05 using t-tests comparing averages). Furthermore, U-Nets trained using data subsets selected by EBC generate segmentations with a distribution of Dice coefficients that demonstrate significantly (p < 0.05 using Bartlett's test) lower variance in comparison to U-Nets trained using random sampling for all datasets. We believe that this lower variance indicates that U-Nets trained with EBC are more robust than U-Nets trained with random sampling.

Patient Safety Analysis in Radiation Burden of Head Computed Tomography Imaging in 1185 Neurosurgical Inpatients.

OBJECTIVE: We performed a retrospective analysis in a cohort of 1185 patients at our institution who were identified as undergoing ≥1 head computed tomography (CT) examinations during their inpatient stay on the neurosurgery service, to quantify the number, type, and associated radiation burden of head CT procedures performed by the neurosurgery service. METHODS: CT procedure records and radiology reports were obtained via database search and directly validated against records retrieved from manual chart review. Next, dosimetry data from the head CT procedures were extracted via automated text mining of electronic radiology reports. RESULTS: Among 4510 identified adult head CT procedures, 88% were standard head CT examinations. A total of 3.65 ± 3.60 head CT scans were performed during an average adult admission. The most common primary diagnoses were neoplasms, trauma, and other hemorrhage. The median cumulative effective dose per admission was 5.66 mSv (range, 1.06-84.5 mSv; mean, 8.56 ± 8.95 mSv). The median cumulative effective dose per patient was 6.4 mSv (range, 1.1-127 mSv; mean, 9.26 ± 10.0 mSv). CONCLUSIONS: The median cumulative radiation burden from head CT imaging in our cohort equates approximately to a single chest CT scan, well within accepted limits for safe CT imaging in adults. Refined methods are needed to characterize the safety profile of the few pediatric patients identified in our study.

Natural history of the aging spine: a cross-sectional analysis of spinopelvic parameters in the asymptomatic population.

OBJECTIVE: There have been numerous studies demonstrating increased pain and disability when patients' spinopelvic parameters fall outside of certain accepted ranges. However, these values were established based on patients suffering from spinal deformities. It remains unknown how these parameters change over a lifetime in asymptomatic individuals. The goal of this study was to define a range of spinopelvic parameters from asymptomatic individuals. METHODS: Sagittal scoliosis radiographs of 210 asymptomatic patients were evaluated. All measurements were reviewed by 2 trained observers, supervised by a trained clinician. The following parameters and relationships were measured or calculated: cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sagittal vertical axis (SVA), cervical SVA (cSVA), and T1 slope, TK/LL, truncal inclination, pelvic tilt (PT), LL-PI, LL/PI, and T1 slope/PI. Patients were stratified by decade of life, and regression analysis was performed to delineate the relationship between each consecutive age group and the aforementioned parameters. RESULTS: Cervical lordosis (R2 = 0.61), thoracic kyphosis (R2 = 0.84), SVA (R2 = 0.88), cSVA (R2 = 0.51), and T1 slope (R2 = 0.77) all increase with age. Truncal inclination (R2 = 0.36) and T1 slope/CL remain stable over all decades (R2 = 0.01). LL starts greater than PI, but in the 6th decade of life, LL becomes equal to PI and in the 7th decade becomes smaller than PI (R2 = 0.96). The ratio of TK/LL is stable until the 7th decade of life (R2 = 0.81), whereas PT is stable until the 6th decade (R2 = 0.92). CONCLUSIONS: This study further refines the generally accepted LL = PI + 10° by showing that patients under the age of 50 years should have more LL compared to PI, whereas after the 5th decade the relationship is reversed. SVA was not as sensitive across age groups, exhibiting a marked increase only in the 7th decade of life. Given the reliable increase of CL with age, and the stability of T1 slope/CL, this represents another important relationship that should be maintained when performing cervical deformity/fusion surgery. This study has important implications for evaluating adult patients with spinal deformities and for establishing corrective surgical goals.

Quantitative Analysis of Neural Foramina in the Lumbar Spine: An Imaging Informatics and Machine Learning Study.

PURPOSE: To use machine learning tools and leverage big data informatics to statistically model the variation in the area of lumbar neural foramina in a large asymptomatic population. MATERIALS AND METHODS: By using an electronic health record and imaging archive, lumbar MRI studies in 645 male (mean age, 50.07 years) and 511 female (mean age, 48.23 years) patients between 20 and 80 years old were identified. Machine learning algorithms were used to delineate lumbar neural foramina autonomously and measure their areas. The relationship between neural foraminal area and patient age, sex, and height was studied by using multivariable linear regression. RESULTS: Neural foraminal areas correlated directly with patient height and inversely with patient age. The associations involved were statistically significant (P < .01). CONCLUSION: By using machine learning and big data techniques, a linear model encoding variation in lumbar neural foraminal areas in asymptomatic individuals has been established. This model can be used to make quantitative assessments of neural foraminal areas in patients by comparing them to the age-, sex-, and height-adjusted population averages.© RSNA, 2019Supplemental material is available for this article.

Next Generation Case Report: Supraorbital Craniotomy for Anterior Communicating Artery Aneurysm Clipping in Annotated Virtual Reality Environment.

BACKGROUND AND IMPORTANCE: Recent years have seen significant advancements in virtual reality. Implementation of this technology in combination with traditional learning methods is a powerful tool for medical teaching. CLINICAL PRESENTATION: This is a 60-yr-old woman who presented with a history of headaches and was found to have an unruptured 4-mm anterior communicating artery aneurysm. After discussion, the patient elected to have the aneurysm treated by surgical clipping. The aneurysm was completely occluded through a supraorbital craniotomy with a single clip. The patient was discharged home in good condition on postoperative day 2. This case was imported into a virtual reality environment with annotated slides and operative video for resident teaching. CONCLUSION: As virtual reality technology continues to grow, library of interactive case reports could revolutionize neurosurgical education.