Identification of metabolites associated with preserved muscle volume after aneurysmal subarachnoid hemorrhage due to high protein supplementation and neuromuscular electrical stimulation.

The INSPIRE randomized clinical trial demonstrated that a high protein diet (HPRO) combined with neuromuscular electrical stimulation (NMES) attenuates muscle atrophy and may improve outcomes after aneurysmal subarachnoid hemorrhage We sought to identify specific metabolites mediating these effects. Blood samples were collected from subjects on admission prior to randomization to either standard of care (SOC; N = 12) or HPRO + NMES (N = 12) and at 7 days. Untargeted metabolomics were performed for each plasma sample. Sparse partial least squared discriminant analysis identified metabolites differentiating each group. Correlation coefficients were calculated between each metabolite and total protein per day and muscle volume. Multivariable models determined associations between metabolites and muscle volume. Unique metabolites (18) were identified differentiating SOC from HPRO + NMES. Of these, 9 had significant positive correlations with protein intake. In multivariable models, N-acetylleucine was significantly associated with preserved temporalis [OR 1.08 (95% CI 1.01, 1.16)] and quadricep [OR 1.08 (95% CI 1.02, 1.15)] muscle volume. Quinolinate was also significantly associated with preserved temporalis [OR 1.05 (95% CI 1.01, 1.09)] and quadricep [OR 1.04 (95% CI 1.00, 1.07)] muscle volume. N-acetylserine and ß-hydroxyisovaleroylcarnitine were associated with preserved temporalis or quadricep volume. Metabolites defining HPRO + NMES had strong correlations with protein intake and were associated with preserved muscle volume.

Advances in chronic subdural hematoma and membrane imaging.

Chronic subdural hematoma (cSDH) is projected to become the most common cranial neurosurgical disease by 2030. Despite medical and surgical management, recurrence rates remain high. Recently, middle meningeal artery embolization (MMAE) has emerged as a promising treatment; however, determinants of disease recurrence are not well understood, and developing novel radiographic biomarkers to assess hematomas and cSDH membranes remains an active area of research. In this narrative review, we summarize the current state-of-the-art for subdural hematoma and membrane imaging and discuss the potential role of MR and dual-energy CT imaging in predicting cSDH recurrence, surgical planning, and selecting patients for embolization treatment.

Acute Development of Traumatic Intracranial Aneurysms After Civilian Gunshot Wounds to the Head.

In previous studies, the incidence of traumatic intracranial aneurysms (TICAs) after civilian gunshot wound to the head (cGSWH) was ∼3%. Given the use of delayed vessel imaging, we hypothesize that a significant fraction of TICAs is missed on initial non-contrasted scans. This study was designed to characterize acute TICAs using admission computed tomographic angiography (aCTA) in cGSWH. Over the period from 2017 to 2022, 341 patients were admitted to R. Adams Cowley Shock Trauma Center with cGSWH; 136 subjects had aCTA ∼3 (standard deviation [SD] 3.5) h post-injury. Demographics, clinical findings, imaging techniques, endovascular/surgical interventions, and outcomes were analyzed. Mean age was 34.7 (SD 13.1), male:female ratio was 120:16. Average admission Glasgow Coma Scale (GCS) score was 6 (SD 3.9). Entry site was frontal in 41, temporal in 55, parietal in 18, occipital in 6, suboccipital in 9, temporo-parietal in 1, and frontobasal-temporal in 6. Projectiles crossed multiple dural compartments in 76 (55%) patients. 35 TICAs were diagnosed in 28 subject: 24 were located along the middle cerebral artery (MCA), 6 in the anterior cerebral artery (ACA), 3 in the internal carotid artery (ICA), 1 in the posterior cerebral artery (PCA), and 1 in the middle meningeal artery (MMA). Eleven TICAs resolved spontaneously in nine patients. Eight aneurysms were treated by endovascular means, two via combined endovascular/open approaches. Forty-nine patients died, 10 of whom had 15 TICAs. Eighty patients developed intracerebral hematoma s (ICHs). Regression models showed that the presence of an ICH was the main predictor of TICA in cGSWH. Larger ICHs (average 22.3 cc vs. 9.4 cc in patients with and without aneurysms, respectively) in patients with cGSWH suggest hidden TICAs. Nearly 30% of patients had spontaneous resolution within 1 week. When CTA was performed acutely, TICAs were 10 times more frequent in cGSWH than in previous literature, and those patients were more likely to proceed to surgery. Almost one third of patients in this series died from the devastating effects of cGSWH.

Quantitative DECT of Iodine in Chronic Subdural Hematoma as Surrogate of Membrane Exudation: A Pilot Feasibility Study.

OBJECTIVE: We explore the feasibility to estimate the exudation from chronic subdural hematoma (CSDH) membranes, by using dual-energy computed tomography (DECT) quantification of iodine leak and test if the derived quantitative variables and membrane morphology correlates with hematoma volume, internal architecture (homogeneous, laminar, separated, and trabecular types), and fractional hyperdense hematoma at presentation. METHODS: In this retrospective study, consecutive CSDH patients with postcontrast DECT head images from January 2020 and June 2021 were analyzed. Predictor variables derived from DECT were correlated with outcome variables followed by mixed-effects regression analysis. RESULTS: The study included 36 patients with 50 observations (mean age, 72.6 years; standard deviation, 11.6 years); 31 were men. Dual-energy CT variables that correlated with hematoma volume were external membrane volume (ρ, 0.37; P = 0.008) and iodine concentration (ρ, -0.29; P = 0.04). Variables that correlated with separated type of hematoma were total iodine leak (median [Q 1 , Q 3 ], 68.3 mg [48.5, 88.9] vs 38.8 mg [15.5, 62.9]; P = 0.001) and iodine leak per unit membrane volume (median [Q 1 , Q 3 ], 16.47 mg/mL [10.19, 20.65] vs 8.68 mg/mL [5.72, 11.41]; P = 0.002). Membrane grade was the only variable that correlated with fractional hyperdense hematoma (ρ, 0.28; P = 0.05). Regression analysis showed total iodine leak as the strongest predictor of separated type hematoma (odds ratio [95% confidence interval], 1.06 per mg [1.01, 1.1]). CONCLUSIONS: Dual-energy CT demonstrates iodine leak from CSDH membranes. The variables derived from DECT correlated with hematoma volume, internal architecture, and fractional hyperdense hematoma.

High-Protein Supplementation and Neuromuscular Electric Stimulation after Aneurysmal Subarachnoid Hemorrhage Increases Systemic Amino Acid and Oxidative Metabolism: A Plasma Metabolomics Approach.

Background: The INSPIRE randomized clinical trial demonstrated that a high protein diet (HPRO) combined with neuromuscular electrical stimulation (NMES) attenuates muscle atrophy and may improve functional outcomes after aSAH. Using an untargeted metabolomics approach, we sought to identify specific metabolites mediating these effects. Methods: Blood samples were collected from subjects on admission prior to randomization to either standard of care (SOC; N=12) or HPRO+NMES (N=12) and at 7 days as part of the INSPIRE protocol. Untargeted metabolomics were performed for each plasma sample. Paired fold changes were calculated for each metabolite among subjects in the HPRO+NMES group at baseline and 7 days after intervention. Changes in metabolites from baseline to 7 days were compared for the HPRO+NMES and SOC groups. Sparse partial least squared discriminant analysis (sPLS-DA) identified metabolites discriminating each group. Pearson's correlation coefficients were calculated between each metabolite and total protein per day, nitrogen balance, and muscle volume Multivariable models were developed to determine associations between each metabolite and muscle volume. Results: A total of 18 unique metabolites were identified including pre and post treatment and differentiating SOC vs HPRO+NMES. Of these, 9 had significant positive correlations with protein intake: N-acetylserine (ρ=0.61, P=1.56×10-3), N-acetylleucine (ρ=0.58, P=2.97×10-3), ß-hydroxyisovaleroylcarnitine (ρ=0.53, P=8.35×10-3), tiglyl carnitine (ρ=0.48, P=0.0168), N-acetylisoleucine (ρ=0.48, P=0.0183), N-acetylthreonine (ρ=0.47, P=0.0218), N-acetylkynurenine (ρ=0.45, P=0.0263), N-acetylvaline (ρ=0.44, P=0.0306), and urea (ρ=0.43, P=0.0381). In multivariable regression models, N-acetylleucine was significantly associated with preserved temporalis [OR 1.08 (95%CI 1.01, 1.16)] and quadricep [OR 1.08 (95%CI 1.02, 1.15)] muscle volume. Quinolinate was also significantly associated with preserved temporalis [OR 1.05 (95%CI 1.01, 1.09)] and quadricep [OR 1.04 (95%CI 1.00, 1.07)] muscle volume. N-acetylserine, N-acetylcitrulline, and b-hydroxyisovaleroylcarnitine were also associated with preserved temporalis or quadricep volume. Conclusions: Metabolites defining the HPRO+NMES intervention mainly consisted of amino acid derivatives. These metabolites had strong correlations with protein intake and were associated with preserved muscle volume.

Iodine-based dual-energy CT predicts early neurological decline from cerebral edema after large hemispheric infarction.

Background & Purpose: Ischemia affecting two thirds of the MCA territory predicts development of malignant cerebral edema. However, early infarcts are hard to diagnose on conventional head CT. We hypothesize that high-energy (190keV) virtual monochromatic images (VMI) from dual-energy CT (DECT) imaging enables earlier detection of secondary injury from malignant cerebral edema (MCE). Methods: Consecutive LHI patients with NIHSS ≥ 15 and DECT within 10 hours of reperfusion from May 2020 to March 2022 were included. We excluded patients with parenchymal hematoma-type 2 transformation. Retrospective analysis of clinical and novel variables included VMI Alberta Stroke Program Early CT Score (ASPECTS), total iodine content, and VMI infarct volume. Primary outcome was early neurological decline (END). Secondary outcomes included hemorrhagic transformation, decompressive craniectomy (DC), and medical treatment of MCE. Fisher's exact test and Wilcoxon test were used for univariate analysis. Logistic regression was used to develop prediction models for categorical outcomes. Results: Eighty-four LHI patients with a median age of 67.5 [IQR 57,78] years and NIHSS 22 [IQR 18,25] were included. Twenty-nine patients had END. VMI ASPECTS, total iodine content, and VMI infarct volume were associated with END. VMI ASPECTS, VMI infarct volume, and total iodine content were predictors of END after adjusting for age, sex, initial NIHSS, and tPA administration, with a AUROC of 0.691 [0.572,0.810], 0.877 [0.800, 0.954], and 0.845 [0.750, 0.940]. By including all three predictors, the model achieved AUROC of 0.903 [0.84,0.97] and was cross validated by leave one out method with AUROC of 0.827. Conclusion: DECT with high-energy VMI and iodine quantification is superior to conventional CT ASPECTS and is a novel predictor for early neurological decline due to malignant cerebral edema after large hemispheric infarction.

Accelerating voxelwise annotation of cross-sectional imaging through AI collaborative labeling with quality assurance and bias mitigation.

Background: precision-medicine quantitative tools for cross-sectional imaging require painstaking labeling of targets that vary considerably in volume, prohibiting scaling of data annotation efforts and supervised training to large datasets for robust and generalizable clinical performance. A straight-forward time-saving strategy involves manual editing of AI-generated labels, which we call AI-collaborative labeling (AICL). Factors affecting the efficacy and utility of such an approach are unknown. Reduction in time effort is not well documented. Further, edited AI labels may be prone to automation bias. Purpose: In this pilot, using a cohort of CTs with intracavitary hemorrhage, we evaluate both time savings and AICL label quality and propose criteria that must be met for using AICL annotations as a high-throughput, high-quality ground truth. Methods: 57 CT scans of patients with traumatic intracavitary hemorrhage were included. No participant recruited for this study had previously interpreted the scans. nnU-net models trained on small existing datasets for each feature (hemothorax/hemoperitoneum/pelvic hematoma; n = 77-253) were used in inference. Two common scenarios served as baseline comparison- de novo expert manual labeling, and expert edits of trained staff labels. Parameters included time effort and image quality graded by a blinded independent expert using a 9-point scale. The observer also attempted to discriminate AICL and expert labels in a random subset (n = 18). Data were compared with ANOVA and post-hoc paired signed rank tests with Bonferroni correction. Results: AICL reduced time effort 2.8-fold compared to staff label editing, and 8.7-fold compared to expert labeling (corrected p < 0.0006). Mean Likert grades for AICL (8.4, SD:0.6) were significantly higher than for expert labels (7.8, SD:0.9) and edited staff labels (7.7, SD:0.8) (corrected p < 0.0006). The independent observer failed to correctly discriminate AI and human labels. Conclusion: For our use case and annotators, AICL facilitates rapid large-scale curation of high-quality ground truth. The proposed quality control regime can be employed by other investigators prior to embarking on AICL for segmentation tasks in large datasets.

Surgical Decompression of Traumatic Cervical Spinal Cord Injury: A Pilot Study Comparing Real-Time Intraoperative Ultrasound After Laminectomy With Postoperative MRI and CT Myelography.

BACKGROUND: Decompression of the injured spinal cord confers neuroprotection. Compared with timing of surgery, verification of surgical decompression is understudied. OBJECTIVE: To compare the judgment of cervical spinal cord decompression using real-time intraoperative ultrasound (IOUS) following laminectomy with postoperative MRI and CT myelography. METHODS: Fifty-one patients were retrospectively reviewed. Completeness of decompression was evaluated by real-time IOUS and compared with postoperative MRI (47 cases) and CT myelography (4 cases). RESULTS: Five cases (9.8%) underwent additional laminectomy after initial IOUS evaluation to yield a final judgment of adequate decompression using IOUS in all 51 cases (100%). Postoperative MRI/CT myelography showed adequate decompression in 43 cases (84.31%). Six cases had insufficient bony decompression, of which 3 (50%) had cerebrospinal fluid effacement at >1 level. Two cases had severe circumferential intradural swelling despite adequate bony decompression. Between groups with and without adequate decompression on postoperative MRI/CT myelography, there were significant differences for American Spinal Injury Association motor score, American Spinal Injury Association Impairment Scale grade, AO Spine injury morphology, and intramedullary lesion length (IMLL). Multivariate analysis using stepwise variable selection and logistic regression showed that preoperative IMLL was the most significant predictor of inadequate decompression on postoperative imaging (P = .024). CONCLUSION: Patients with severe clinical injury and large IMLL were more likely to have inadequate decompression on postoperative MRI/CT myelography. IOUS can serve as a supplement to postoperative MRI/CT myelography for the assessment of spinal cord decompression. However, further investigation, additional surgeon experience, and anticipation of prolonged swelling after surgery are required.

Blunt splenic injury in adults: Association between volumetric quantitative CT parameters and intervention.

Several ordinal grading systems are used in deciding whether to perform angioembolization (AE) or splenectomy following blunt splenic injury (BSI). The 2018 American Association for the Surgery of Trauma (AAST) Organ Injury Scale incorporates vascular lesions but not hemoperitoneum, which is considered in the Thompson classifier. Granular and verifiable quantitative measurements of these features may have a future role in facilitating objective decision making. The purpose of this study is to compare performance of computed tomography (CT) volumetry-based quantitative modeling to the 1994 and 2018 AAST Organ Injury Scale and Thompson classifier for the following endpoints: decision to perform splenectomy (SPY), and the composite of SPY or AE. Adult BSI patients (age ≥18 years) scanned with dual-phase CT prior to intervention at a single Level I trauma center from 2017 to 2019 were included in this retrospective study (n = 174). Scoring using 2018 AAST, 1994 AAST, and Thompson systems was performed retrospectively by two radiologists and arbitrated by a third. Endpoints included (1) SPY and (2) the composite of SPY or AE. Logistic regression models were developed from segmented active bleed, contained vascular lesion, splenic parenchymal disruption, and hemoperitoneum volumes. Area under the receiver operating characteristic curve (AUC) for ordinal systems and volumetric models were compared. Forty-seven BSI patients (27%) underwent SPY, and 87 patients (50%) underwent SPY or AE. Quantitative model AUCs (0.85­SPY, 0.82­composite) were not significantly different from 2018 AAST AUCs (0.81, 0.88, p = 0.66, 0.14) for both endpoints and were significantly improved over Thompson scoring (0.76, p = 0.02; 0.77, p = 0.04). Quantitative CT volumetry can be used to model intervention for BSI with accuracy comparable to 2018 AAST scoring and significantly higher than Thompson scoring. Prognostic and Epidemiological; Level IV.

Dual-energy CT imaging of chronic subdural hematoma membranes: technical note.

This technical note describes a novel dual-energy CT (DECT) protocol with iodine map reconstruction that will enable visualization of chronic subdural hematoma (CSDH) membranes. We describe the technique and discuss the potential implications for surgical management. The cohort included 36 patients with 50 hematomas. Enhancing external membrane was demonstrated in all the 50 hematomas, incomplete internal membrane in 13, and complete internal membrane in 23 hematomas. A spandrel sign at the transition zone that indicates partial or complete formation of internal membrane was demonstrated in 36 hematomas. KEY POINTS: • Iodine maps from 5-min delayed post-contrast DECT provide spectral contrast difference and facilitate segregation of chronic subdural hematoma membranes. • The ability to image the membranes helps in assessing the degree of organization of the hematoma by providing the information about the membrane thickness, volume, complexity of the membranes, and the proportion of the liquefied component within the hematoma before surgical procedures are undertaken. • Membrane visualization helps in the localization of the transition zone and extension of the membranes over the cerebral lobes helping in the determination of craniotomy location and size, during membranectomy.

Blood Pressure Variability and Outcome in Traumatic Brain Injury: A Propensity Score Matching Study.

INTRODUCTION: Patients with tIPH (used here to refer to traumatic intraparenchymal hemorrhagic contusion) or intraparenchymal hemorrhage face high rates of mortality and persistent functional deficits. Prior studies have found an association between blood pressure variability (BPV) and neurologic outcomes in patients with spontaneous IPH. Our study investigated the association between BPV and discharge destination (a proxy for functional outcome) in patients with tIPH. METHODS: We retrospectively reviewed the charts of patients admitted to a Level I trauma center for ≥ 24 hours with tIPH. We examined variability in hourly BP measurements over the first 24 hours of hospitalization. Our outcome of interest was discharge destination (home vs facility). We performed 1:1 propensity score matching and multivariate regressions to identify demographic and clinical factors predictive of discharge home. RESULTS: We included 354 patients; 91 were discharged home and 263 to a location other than home. The mean age was 56 (SD 21), 260 (73%) were male, 22 (6%) were on anticoagulation, and 54 (15%) on antiplatelet therapy. Our propensity-matched cohorts included 76 patients who were discharged home and 76 who were discharged to a location other than home. One measure of BPV (successive variation in systolic BP) was identified as an independent predictor of discharge location in our propensity-matched cohorts (odds ratio 0.89, 95% confidence interval 0.8-0.98; P = 0.02). Our model demonstrated good goodness of fit (P-value for Hosmer-Lemeshow test = 0.88) and very good discriminatory capability (AUROC = 0.81). High Glasgow Coma Scale score at 24 hours and treatment with fresh frozen plasma were also associated with discharge home. CONCLUSION: Our study suggests that increased BPV is associated with lower rates of discharge home after initial hospitalization among patients with tIPH. Additional research is needed to evaluate the impact of BP control on patient outcomes.

Artificial Intelligence with Statistical Confidence Scores for Detection of Acute or Subacute Hemorrhage on Noncontrast CT Head Scans.

Purpose: To present a method that automatically detects, subtypes, and locates acute or subacute intracranial hemorrhage (ICH) on noncontrast CT (NCCT) head scans; generates detection confidence scores to identify high-confidence data subsets with higher accuracy; and improves radiology worklist prioritization. Such scores may enable clinicians to better use artificial intelligence (AI) tools. Materials and Methods: This retrospective study included 46 057 studies from seven "internal" centers for development (training, architecture selection, hyperparameter tuning, and operating-point calibration; n = 25 946) and evaluation (n = 2947) and three "external" centers for calibration (n = 400) and evaluation (n = 16 764). Internal centers contributed developmental data, whereas external centers did not. Deep neural networks predicted the presence of ICH and subtypes (intraparenchymal, intraventricular, subarachnoid, subdural, and/or epidural hemorrhage) and segmentations per case. Two ICH confidence scores are discussed: a calibrated classifier entropy score and a Dempster-Shafer score. Evaluation was completed by using receiver operating characteristic curve analysis and report turnaround time (RTAT) modeling on the evaluation set and on confidence score-defined subsets using bootstrapping. Results: The areas under the receiver operating characteristic curve for ICH were 0.97 (0.97, 0.98) and 0.95 (0.94, 0.95) on internal and external center data, respectively. On 80% of the data stratified by calibrated classifier and Dempster-Shafer scores, the system improved the Youden indexes, increasing them from 0.84 to 0.93 (calibrated classifier) and from 0.84 to 0.92 (Dempster-Shafer) for internal centers and increasing them from 0.78 to 0.88 (calibrated classifier) and from 0.78 to 0.89 (Dempster-Shafer) for external centers (P < .001). Models estimated shorter RTAT for AI-prioritized worklists with confidence measures than for AI-prioritized worklists without confidence measures, shortening RTAT by 27% (calibrated classifier) and 27% (Dempster-Shafer) for internal centers and shortening RTAT by 25% (calibrated classifier) and 27% (Dempster-Shafer) for external centers (P < .001). Conclusion: AI that provided statistical confidence measures for ICH detection on NCCT scans reliably detected and subtyped hemorrhages, identified high-confidence predictions, and improved worklist prioritization in simulation.Keywords: CT, Head/Neck, Hemorrhage, Convolutional Neural Network (CNN) Supplemental material is available for this article. © RSNA, 2022.

Dual-Energy CT and Cinematic Rendering to Improve Assessment of Pelvic Fracture Instability.

Background Grading of pelvic fracture instability is challenging in patients with pelvic binders. Dual-energy CT (DECT) and cinematic rendering can provide ancillary information regarding osteoligamentous integrity, but the utility of these tools remains unknown. Purpose To assess the added diagnostic value of DECT and cinematic rendering, with respect to single-energy CT (SECT), for discriminating any instability and translational instability in patients with pelvic binders. Materials and Methods In this retrospective analysis, consecutive adult patients (age ≥18 years) were stabilized with pelvic binders and scanned in dual-energy mode using a 128-section CT scanner at one level I trauma center between August 2016 and January 2019. Young-Burgess grading by orthopedists served as the reference standard. Two radiologists performed blinded consensus grading with the Young-Burgess system in three reading sessions (session 1, SECT; session 2, SECT plus DECT; session 3, SECT plus DECT and cinematic rendering). Lateral compression (LC) type 1 (LC-1) and anteroposterior compression (APC) type 1 (APC-1) injuries were considered stable; LC type 2 and APC type 2, rotationally unstable; and LC type 3, APC type 3, and vertical shear, translationally unstable. Diagnostic performance for any instability and translational instability was compared between reading sessions using the McNemar and DeLong tests. Radiologist agreement with the orthopedic reference standard was calculated with the weighted κ statistic. Results Fifty-four patients (mean age, 41 years ± 16 [SD]; 41 men) were analyzed. Diagnostic performance was greater with SECT plus DECT and cinematic rendering compared with SECT alone for any instability, with an area under the receiver operating characteristic curve (AUC) of 0.67 for SECT alone and 0.82 for SECT plus DECT and cinematic rendering (P = .04); for translational instability, the AUCs were 0.80 for SECT alone and 0.95 for SECT plus DECT and cinematic rendering (P = .01). For any instability, corresponding sensitivities were 61% (22 of 36 patients) for SECT alone and 86% (31 of 36 patients) for SECT plus DECT and cinematic rendering (P < .001). The corresponding specificities were 72% (13 of 18 patients) and 78% (14 of 18 patients), respectively (P > .99). Agreement (κ value) between radiologists and orthopedist reference standard improved from 0.44 to 0.76 for SECT versus the combination of SECT, DECT, and cinematic rendering. Conclusion Combined use of single-energy CT, dual-energy CT, and cinematic rendering improved instability assessment over that with single-energy CT alone. © RSNA, 2022 Online supplemental material is available for this article.

Blunt Cerebrovascular Injury-Like Injury Observed in Patients With Craniofacial Self-Inflicted Gunshot Wounds.

BACKGROUND: Although blunt cerebrovascular injury (BCVI) is recognized as a risk factor for trauma morbidity and mortality, little is described regarding similar cerebrovascular injury (CVI) in patients with penetrating wounds. The authors aim to characterize these injuries in the craniofacial self-inflicted gunshot wound (SIGSW) population. METHODS: An institutional review board (IRB)-approved retrospective nstudy was conducted on patients presenting to the R Adams Cowley Shock Trauma Center with SIGSWs between 2007 and 2016. All CVIs were categorized by location, type, and associated neurologic deficits. Demographic data, patient characteristics, additional studies, and long-term outcomes were collected. A multivariate analysis determining independent predictors of CVI in the SIGSW population was performed. RESULTS: Of the 73 patients with SIGSWs, 5 (6.8%) had CVIs separate from the bullet/cavitation tract (distant CVIs) and 9 had CVIs along the bullet/cavitation tract (in-tract CVIs). A total of 55.6% of in-tract and 40% of distant injuries were missed on initial radiology read. One distant CVI patient suffered a stroke during admission. The anterior to posterior gunshot wound trajectory was positively associated with distant CVIs when compared with no CVIs ( P  = 0.01). Vessel dissection was more prevalent in patients with distant CVIs, when compared against patients with in-tract CVIs ( P  = 0.02). CONCLUSIONS: Nearly 20% of craniofacial SIGSW patients have CVIs and 6.8% have BCVI-like injuries, which is 2-to-6-fold times higher than traditional BCVIs. Craniofacial SIGSWs serve as an independent screening criterion with comparable screening yields; the authors recommend radiographic screening for these patients with particular scrutiny for CVIs as they are frequently missed on initial radiographic interpretations.

Traumatic brain injury and intraparenchymal hemorrhage progression: Blood pressure variability matters.

INTRODUCTION: Blood pressure variability (BPV) has been shown to correlate with intraparenchymal hematoma progression (HP) and worse outcomes in patients with spontaneous intracerebral hemorrhage (sICH). However, this association has not been elucidated in patients with traumatic intraparenchymal hemorrhage or contusion (tIPH). We hypothesized that 24 h-BPV from time of admission is associated with hemorrhagic progression of contusion or intraparenchymal hemorrhage (HPC), and worse outcomes in patients with tIPH. METHOD: We performed a retrospective observational analysis of adult patients treated at an academic regional Level 1 trauma center between 01/2018-12/2019. We included patients who had tIPH and ≥ 2 computer tomography (CT) scans within 24 h of admission. HP, defined as ≥30% of admission hematoma volume, was calculated by the ABC/2 method. We performed stepwise multivariable logistic regressions for the association between clinical factors and outcomes. RESULTS: We analyzed 354 patients' charts. Mean age (Standard Deviation [SD]) was 56 (SD = 21) years, 260 (73%) were male. Mean admission hematoma volume was 7 (SD =19) cubic centimeters (cm3), 160 (45%) had HP. Coefficient of variation in systolic blood pressure (SBPCV) (OR 1.03, 95%CI 1.02-1.3, p = 0.026) was significantly associated with HPC among patients requiring external ventricular drain (EVD). Difference between highest and lowest systolic blood pressure (SBPmax-min) (OR 1.02, 95%CI 1.004-1.03, p = 0.007) was associated with hospital mortality. CONCLUSION: SBPCV was significantly associated with HP among patients who required EVD. Additionally, increased SBPmax-min was associated with an increase in mortality. Clinicians should be cautious with patients' blood pressure until further studies confirm these observations.

Principles and Applications of Dual Energy Computed Tomography in Neuroradiology.

Dual-energy computed tomography (DE CT) is a promising tool with many current and evolving applications. Available DE CT scanners usually consist of one or two tubes, or use layered detectors for spectral separation. Most DE CT scanners can be used in single energy or dual-energy mode, except for the layered detector scanners that always acquire data in dual-energy mode. However, the layered detector scanners can retrospectively integrate the data from two layers to obtain conventional single energy images. DE CT mode enables generation of virtual monochromatic images, blended images, iodine quantification, improving conspicuity of iodinated contrast enhancement, and material decomposition maps or more sophisticated quantitative analysis not possible with conventional SE CT acquisition with an acceptable or even lower dose than the SE CT. This article reviews the basic principles of dual-energy CT and highlights many of its clinical applications in the evaluation of neurological conditions.

Segmental Bowel Hypoenhancement on CT Predicts Ischemic Mesenteric Laceration After Blunt Trauma.

OBJECTIVE. The objectives of this study were to examine the performance of CT in the diagnosis of ischemic mesenteric laceration after blunt trauma and to assess the predictive value of various CT signs for this injury. MATERIALS AND METHODS. In this retrospective study, consecutive patients with bowel and mesenteric injury diagnosed by CT or surgery from January 2011 through December 2016 were analyzed. Two radiologists evaluated CT images for nine signs of bowel injury. The outcome evaluated was ischemic mesenteric laceration. Univariable analysis followed by logistic regression was performed. RESULTS. The study included 147 patients (96 men and 51 women; median age, 35 years; age range, 23-52 years). Thirty-three patients had surgically confirmed ischemic mesenteric lacerations. CT signs that correlated with ischemic mesenteric laceration were abdominal wall injury, mesenteric contusion, free fluid, segmental bowel hypoenhancement, and bowel hyperenhancement adjacent to a hypoenhancing segment. The regression model developed after inclusion of clinical variables identified two predictors: segmental bowel hypoenhancement (adjusted odds ratio, 22.9 [95% CI, 7.9-66.2; p < .001] for reviewer 1 and 20.7 [95% CI, 7.2-59.0; p < .001] for reviewer 2) and abdominal wall injury (adjusted odds ratio, 5.26 [95% CI, 1.7-15.9; p = .003] for reviewer 1 and 5.3 [95% CI, 1.9-15.0; p = .002] for reviewer 2), which yielded an AUC of 0.87 for predicting injury. For reviewer 1 and reviewer 2, the sensitivities of CT in detecting the injury were 72.3% (95% CI, 54.5-86.7%) and 78.8% (95% CI, 61.0-91.0%), respectively, whereas the specificities were 94.7% (95% CI, 88.9-98.0%), and 92.1% (95% CI, 85.5-96.3%), respectively. CONCLUSION. CT has limited sensitivity but good specificity for detecting ischemic mesenteric laceration, with segmental bowel hypoenhancement considered the most predictive imaging sign.

An Automated Deep Learning Method for Tile AO/OTA Pelvic Fracture Severity Grading from Trauma whole-Body CT.

Admission trauma whole-body CT is routinely employed as a first-line diagnostic tool for characterizing pelvic fracture severity. Tile AO/OTA grade based on the presence or absence of rotational and translational instability corresponds with need for interventions including massive transfusion and angioembolization. An automated method could be highly beneficial for point of care triage in this critical time-sensitive setting. A dataset of 373 trauma whole-body CTs collected from two busy level 1 trauma centers with consensus Tile AO/OTA grading by three trauma radiologists was used to train and test a triplanar parallel concatenated network incorporating orthogonal full-thickness multiplanar reformat (MPR) views as input with a ResNeXt-50 backbone. Input pelvic images were first derived using an automated registration and cropping technique. Performance of the network for classification of rotational and translational instability was compared with that of (1) an analogous triplanar architecture incorporating an LSTM RNN network, (2) a previously described 3D autoencoder-based method, and (3) grading by a fourth independent blinded radiologist with trauma expertise. Confusion matrix results were derived, anchored to peak Matthews correlation coefficient (MCC). Associations with clinical outcomes were determined using Fisher's exact test. The triplanar parallel concatenated method had the highest accuracies for discriminating translational and rotational instability (85% and 74%, respectively), with specificity, recall, and F1 score of 93.4%, 56.5%, and 0.63 for translational instability and 71.7%, 75.7%, and 0.77 for rotational instability. Accuracy of this method was equivalent to the single radiologist read for rotational instability (74.0% versus 76.7%, p = 0.40), but significantly higher for translational instability (85.0% versus 75.1, p = 0.0007). Mean inference time was < 0.1 s per test image. Translational instability determined with this method was associated with need for angioembolization and massive transfusion (p = 0.002-0.008). Saliency maps demonstrated that the network focused on the sacroiliac complex and pubic symphysis, in keeping with the AO/OTA grading paradigm. A multiview concatenated deep network leveraging 3D information from orthogonal thick-MPR images predicted rotationally and translationally unstable pelvic fractures with accuracy comparable to an independent reader with trauma radiology expertise. Model output demonstrated significant association with key clinical outcomes.

Comparison of Acute Diffusion Tensor Imaging and Conventional Magnetic Resonance Parameters in Predicting Long-Term Outcome after Blunt Cervical Spinal Cord Injury.

This prospective longitudinal study compares the ability of conventional and diffusion tensor imaging (DTI) parameters made at the cervical spinal cord injury (CSCI) site to predict long-term neurological and functional outcomes. Twenty patients with CSCI, with follow-up at 6 or 12 months, and 15 control volunteers were included. Conventional magnetic resonance imaging (MRI) and DTI parameters were measured on admission and follow-up studies. Stepwise regression analysis was performed to find relevant parameters (normalized DTI values, conventional MRI measurements, hemorrhagic contusion [HC] or non-HC [NHC]) that correlated with three primary outcome measures: patient International Standards for Neurological Classification of Spinal Cord Injury total motor score (ISNCSCI-TMS), ability to walk, and expected recovery of upper limb motor scores (ER-ULMS) at 6 or 12 months. Univariate analysis showed HC (p < 0.0001 to 0.0098), lesion length on follow-up MRI (p < 0.0001 to 0.019), mean diffusivity (p = 0.01 to 0.045), and axial diffusivity (p = 0.004 to 0.023) predicted all three primary outcomes. Conspicuity of HC was significantly better on axial susceptibility-weighted imaging (SWI) compared with T2* images (p = 0.0009). A negative correlation existed between HC volumes on sagittal SWI images and follow-up ISNCSCI-TMS ( p = 0.02). The regression model identified NHC as the best predictor of the ability to walk (sensitivity = 88.9%; specificity = 100%; positive predictive value = 100%; negative predictive value = 91%; p < 0.0001) and lesion length on follow-up MRI as the best predictor of ER-ULMS (ß coefficient = 0.12, standard error [SE] = 0.07; R2 = 0.64; p = 0.0002). Finally, NHC (ß coefficient = 24.2, SE = 3.7; p < 0.0001) and lesion length on initial MRI (ß coefficient = 0.78, SE = 0.2; p = 0.002) were the best predictors of ISNCSCI-TMS (R2 = 0.83; p < 0.0001). Our study demonstrates HC and follow-up lesion length are potential neuroimaging biomarkers in predicting long-term neurological and functional outcome following blunt CSCI.

Iodine-based Dual-Energy CT of Traumatic Hemorrhagic Contusions: Relationship to In-Hospital Mortality and Short-term Outcome.

BackgroundTraumatic hemorrhagic contusions are associated with iodine leak; however, quantification of leakage and its importance to outcome is unclear.PurposeTo identify iodine-based dual-energy CT variables that correlate with in-hospital mortality and short-term outcomes for contusions at hospital discharge.Materials and MethodsIn this retrospective study, consecutive patients with contusions from May 2016 through January 2017 were analyzed. Two radiologists evaluated CT variables from unenhanced admission head CT and follow-up head dual-energy CT scans obtained after contrast material-enhanced whole-body CT. The outcomes evaluated were in-hospital mortality, Rancho Los Amigos scale (RLAS) score, and disability rating scale (DRS) score. Logistic regression and linear regression were used to develop prediction models for categorical and continuous outcomes, respectively.ResultsThe study included 65 patients (median age, 48 years; interquartile range, 25-65.5 years); 50 were men. Dual-energy CT variables that correlated with mortality, RLAS score, and DRS score were iodine concentration, pseudohematoma volume, iodine quantity in pseudohematoma, and iodine quantity in contusion. The single-energy CT variable that correlated with mortality, RLAS score, and DRS score was hematoma volume at follow-up CT. Multiple logistic regression analysis after inclusion of clinical variables identified two predictors that enabled determination of mortality: postresuscitation Glasgow coma scale (P-GCS) (adjusted odds ratio, 0.42; 95% confidence interval [CI]: 0.2, 0.86; P = 0.01) and iodine quantity in pseudohematoma (adjusted odds ratio, 1.4 per milligram; 95% CI: 1.02 per milligram, 1.9 per milligram; P = 0.03), with a mean area under the receiver operating characteristic curve of 0.96 ± 0.05 (standard error). For RLAS, the predictors were P-GCS (mean coefficient, 0.32 ± 0.06; P < .001) and iodine quantity in contusion (mean coefficient, -0.04 per milligram ± 0.02; P = 0.01). Predictors for DRS were P-GCS (mean coefficient, -1.15 ± 0.27; P < .001), age (mean coefficient, 0.13 per year ± 0.04; P = .002), and iodine quantity in contusion (mean coefficient, 0.19 per milligram ± 0.07; P = .02).ConclusionIodine-based dual-energy CT variables correlate with in-hospital mortality and short-term outcomes for contusions at hospital discharge.© RSNA, 2019Online supplemental material is available for this article.See also the editorial by Talbott and Hess in this issue.