Cervical CT Research Articles

C1 C2 spinal cord compression in hereditary multiple exostoses: case report and review of the literature.

Introduction and importanceHereditary multiple exostoses (HME) is a benign disease, usually encountered in the metaphysis of long bones. On the opposite, spinal localizations are very rare. We herein describe a case of HME with a spinal cord compression.Case presentationA 31-years-old patient with a history of HME, presented with signs of cervical spinal cord compression that progressively appeared in the last 10 years. Cervical MRI and CT scan showed a compressive osseous tumor arising from the surface of the right side of the dorsal arch of the axis. Our patient underwent C1C2 laminectomy, but no clinical improvement has been recorded postoperatively.Clinical discussionSpinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). The cervical and thoracic areas were predominantly affected, with the symptoms usually developing slowly. Early surgery is correlated to good postoperative outcomes.ConclusionDespite its rarity, HME should be considered as a possible cause for spinal cord compression.

Is Cervical Spine CT Sufficient in Pediatric Blunt Trauma? an Analysis of Cervical Spine Pathology Discovered on Magnetic Resonance Imaging after Normal Computed Tomography Scan in a Level I Pediatric Trauma Center

Is Cervical Spine CT Sufficient in Pediatric Blunt Trauma? an Analysis of Cervical Spine Pathology Discovered on Magnetic Resonance Imaging after Normal Computed Tomography Scan in a Level I Pediatric Trauma Center

Patient specific predictive factors of vertebral artery injury following blunt cervical spine trauma

ObjectiveDetermine patient and injury characteristics predictive of vascular injury (VAI) in blunt cervical spine (BCS) trauma to identify high-risk patients and propose an alternative screening protocol. MethodsPatients presenting between 2014 and 2018 with BCS injury and cervical spine CT imaging were included. Demographics and injury characteristics of BCS injuries were collected. Univariate and multivariate analyses to determine risk factors for VAI were performed. Once factors associated with greater odds of VAI were identified, this information was used to create an alternative protocol for indicating CTA in patients who sustained BCS injury. ResultsA total of 475 patients were included. CTA of the neck was performed in 55.5% patients. In patients who received CTA, 18.2% had a contraindication to receiving anti-platelet therapy, and 25% were already receiving anti-coagulation therapy as an outpatient medication. VAI was found in 13.2% patients. In patients with VAI, 48.5% were already receiving anti-coagulation as outpatient medication. Acute kidney injury was found in 10.5% patients who had received CTA.Factors associated with greater odds of having VAI included transverse foramen involvement(p = 0.0001), subluxation/displacement/dislocation of fracture(p = 0.03), high energy mechanism(p = 0.02), SLIC score > 4(p = 0.04), and concomitant lumbar spine injury(p = 0.03).Using Modified Hawkeye Protocol, 40.2% of patients were indicated to receive a CTA, and 17 VAI were identified. Compared to Denver Criteria, CTAs were performed in 73 less patients(p = 0.04). ConclusionsUpdated protocols utilizing evidence-based clinical parameters to predict chance of VAI may avoid unnecessary advanced imaging and contrast load to patients in the setting of BCS trauma.

Correlation Analysis for Selection of Microtitanium Plates with Different Specifications for Use in a Cervical Vertebral Dome Expansion Laminoplasty.

ObjectiveTo analyze correlations between the selection of microtitanium plates with different specifications for use in a cervical vertebral dome expansion laminoplasty.MethodsSixteen patients that underwent the cervical vertebral dome expansion laminoplasty with a cervical spinal stenosis angioplasty procedure for treatment of their cervical spinal cords were recruited at our hospital. From February 2017 to September 2018, medical records confirmed that all patients underwent cervical CT and MRI tests pre‐ and postsurgery. The anteroposterior diameter of the spinal canal, changes in the cross‐sectional area of the spinal canal, and the pre‐ and postsurgery distance of the cervical spinal cord after applying microtitanium plates with different lengths were measured by Mimics version 17.0 software (Materialise NV, Leuven, Belgium). A statistical regression and correlation analysis of relevant specification parameters of the microtitanium plate was then studied.ResultsAs the size of the microtitanium plate increased, we found that the cross‐sectional area of cervical spinal canal and distance between the descendants of the lamina and the distance of cervical spinal cord concordantly increased, and these data changes linearly. The regression equation associated with sagittal diameter, cross‐sectional area, and posterior movement distance of the cervical spinal cord was obtained.ConclusionAccording to the correlation analysis of imaging data changes, the regression equation was obtained to guide the selection of microtitanium plates with appropriate specifications in a cervical vertebral dome expansion laminoplasty.

Calcium pyrophosphate crystal deposition in a cohort of 57 patients with Gitelman syndrome.

Gitelman syndrome (GS) is the most frequent salt-wasting genetic tubulopathy and a source of hypokalaemia and hypomagnesemia. Chondrocalcinosis (CC) is a frequent feature of GS. The aim of our study was to determine the prevalence, distribution patterns, clinical phenotypes and risk factors for CC in GS. This prospective study of a cohort of 57 patients with GS included a systematic screening for CC by peripheral joint radiography, cervical spine CT and joint US. The prevalence of cervical C1-C2 CC by CT was compared between 33 GS patients and sex- and age-matched controls. Clinical and biochemical features were analysed to identify factors associated with CC. Mean (s.d.) age of patients was 46.5 (12.4) years, 66.7% were women and 93.0% carried SLC12A3 mutations. Mean serum magnesium level was 0.60 (0.30) mmol/l. CC was observed in 79% of patients, with the highest prevalence at the cervical spine (81.8%) followed by the knee (52.6%), wrist (50.9%), ankle (38.6%), TM joint (36.4%), shoulder (33.3%), hip (22.8%), elbow (14.0%) and sclerochoroid (12.1%). Prevalence of CC at the C1-C2 level was higher in the GS cohort than control group (72.7% vs 9.1%) (adjusted odds ratio 21.0, 95% CI 2.8, 156.1, P = 0.003). Independent factors associated with CC were low serum magnesium level and age. GS was associated with widespread CC, favoured by aging and hypomagnesemia. The C1-C2 level was the most affected site. Follow-up of this unique cohort will help understanding the clinical consequences of CC, especially the precise characterization of pyrophosphate arthropathy.

257. Patient specific predictive factors of vertebral artery injury following blunt cervical spine trauma

<h3>BACKGROUND CONTEXT</h3> Computed topography angiography (CTA) is routinely used in evaluation for vascular injury in patients that have sustained blunt cervical spine trauma. Current screening criteria often leads to over utilization of imaging in patients who are already receiving antithrombic therapy or have clear contraindications due to concomitant injuries. <h3>PURPOSE</h3> This study sought to identify patient and injury characteristics predictive of vascular injury (VAI) in blunt cervical spine trauma in order to identify high-risk patients and propose alternative screening criteria. <h3>STUDY DESIGN/SETTING</h3> This was a retrospective cohort study collected from patients presenting for blunt cervical spine injury between 2014-2018 at a level I trauma tertiary care center. <h3>PATIENT SAMPLE</h3> A total of 475 patients over the age of 18 who sustained blunt cervical spine trauma and had available cervical spine CT were included in analysis. <h3>OUTCOME MEASURES</h3> 1) Incidence of vertebral artery injuries (VAI) in blunt cervical spine injury. 2) In patients with VAI, percentage of patients with contraindication to anti-platelet therapy OR receiving anti-platelet therapy prior to injury. 3) In patients with VAI, percentage of patients that developed acute kidney injury. 4) Injury and patient characteristics associated with higher risk of sustaining VAI. <h3>METHODS</h3> This was a retrospective cohort study collected from patients presenting for blunt cervical spine injury between 2014-2018. Patients were included who sustained a cervical spine injury and cervical spine CT was available. Demographics including age, gender, outpatient aspirin use, presence of kidney disease was recorded. Injury characteristics including mechanism of action, level of cervical spine injury, type of injury, concomitant thoracic and/or lumbar spine injury, if CTA was obtained, presence of VAI, operative interventions, and subaxial-cervical spine injury classification (SLIC) was collected. Data was evaluated using univariate and multivariate analyses to determine risk factors for VAI. <h3>RESULTS</h3> A total of 475 patients were included, average age 60.2 years. Motor vehicle accident was the most common cause of injury in 225 (47.4%) patients. CTA of the neck was performed in 264 (55.5%) patients. In patients who received CTA, 48 (18.2%) had a contraindication to receiving anti-platelet therapy and 66 (25%) were already receiving anti-platelet therapy as an outpatient medication. 26 (5.5%) patients were found to have VAI, and in patients with VAI, 4 (14.3%) patents were already receiving ASA as an outpatient medication, and no patients required secondary vascular interventions. Acute kidney injury was found in 28 (10.5%) patients who had received CTA. Factors associated with greater odds of having VAI included transverse foramen involvement (OR4.27, CI 2.05-8.89, p=0.0001), multilevel cervical spine fractures (OR2.09, CI 0.97-4.99), subluxation/displacement/dislocation of fracture (OR2.23, CI 1.08-4.59,p=0.03), high energy mechanism (OR2.38, CI 1.14-4.96), SLIC score >4 (OR2.65, CI 1.07-6.55,p=0.04), and concomitant lumbar spine injury (OR4.37, CI 1.13-16.9,p=0.03). <h3>CONCLUSIONS</h3> Updated protocols utilizing evidence-based clinical parameters to predict chance of VAI may avoid unnecessary advanced imaging and contrast load to patients in the setting of blunt cervical spine trauma. Further prospective studies are needed to determine if identified risk factors could be used as specific screening criteria to identify high-risk patients who would benefit most from further advanced imaging. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P117. Bone density distribution in the cervical spine: Establishing level specific reference values

<h3>BACKGROUND CONTEXT</h3> Bone density in the lumbar spine is variable by level and can impact surgical strategy. In the cervical spine, low Hounsfield units (HU) have been associated with cage subsidence. The distribution of HU in the cervical spine has not been established. <h3>PURPOSE</h3> To define level-specific cervical HU reference values and the relationship between cervical bone density, age, BMI, comorbidities and alignment. <h3>STUDY DESIGN/SETTING</h3> Retrospective review at a single center from May 2015 to December 2019. <h3>PATIENT SAMPLE</h3> A total of 224 patients, 18 excluded for previous hardware and 5 for known osteoporosis. <h3>OUTCOME MEASURES</h3> Hounsfield units. <h3>METHODS</h3> Patients who presented with neck symptoms and had a cervical spine CT for evaluation of pathology or surgical planning were included. Exclusions were hardware on CT, osteoporosis, or cervical deformity. Measurements were performed in 5 regions of each vertebral body (VB) (C2-T1; mid-axial, anterior-axial, posterior-axial, mid-coronal, and mid-sagittal) and 2 regions of the lateral masses (LMs) (C3-C6; mid-cor, mid-sag). The VB measurements were averaged at each level to obtain a composite value of each vertebral body (TotalVB), similarly the mid-cor and mid-sag values were averaged at each LM (TotalLatM). Outliers were excluded pairwise. To evaluate reliability, 6 observers each measured 355 HU values (71 over 5 patients), inter-relater reliability assessed with intraclass correlation coefficients (ICCs). Correlations of composite HU with age, BMI, Charlston Comorbidity Index (CCI) and cervical alignment were evaluated. <h3>RESULTS</h3> Average age 57±12 years, mean BMI 28±6 kg/m2, 63.5% male, 90.1% white. Diagnoses included radiculopathy (45.8%), myelopathy (37.9%) and facet arthropathy (46.3%). ICC for HU measurements were as follows: VB, 0.82 mid-axial, 0.59 ant-axial, 0.77 post-axial, 0.88 mid-cor, 0.88 mid-sag; LM, 0.46 mid-sag, 0.61 mid-cor. C4 VB and C4 LM had the highest HU (383.6±71.9 and 480.0±103, respectively) while T1 VB and C6 LM had the lowest (232.3±46.5 and 398.3±98.2, respectively). No significant correlations were found between LM HU and age, BMI, CCI, or alignment. Increased kyphosis was weakly correlated with VB HU at all levels (except C2) strongest correlations at C7 (0.25) and weakest correlation at C3 (0.16). Age and CCI showed weak-moderate correlations with VB HU at all levels (age, r=-0.20 to -0.35; CCI r=-0.28 [C2, C7, T1] to -0.17 [C4]). <h3>CONCLUSIONS</h3> Our level-specific cervical HU values may be referenced when evaluating cervical BMD. The most reliable measurement technique is on the mid-sag or mid-cor VB, measurement of LMs is less reliable. Bone is least dense in the lower cervical spine, which may influence instrumentation strategies. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P49. Cervical spine CT scans can miss fractures when football equipment is in place

<h3>BACKGROUND CONTEXT</h3> Iatrogenic worsening of a spinal injury can result in significant harm to football athletes and complicate its management when equipment is removed in the acute setting by inexperienced personnel. Spine imaging before removal of protective equipment mitigates this risk. There is a controversy regarding the ideal timing of equipment removal and whether current diagnostic imaging modalities are effective to detect these injuries without equipment removal. Prior data suggests that CT is a diagnostic modality for this purpose, however, radiologists' accuracy in detecting specific fractures must be investigated. However, there is no established modality to perform imaging in these patients with protective equipment in place. <h3>PURPOSE</h3> 1) Does the introduction of football equipment result in a reduction in sensitivity for cervical spine fracture detection? (2 What proportion of images that were determined to be of adequate diagnostic quality by experienced radiologists contained missed fractures that were previously identified in the images without football equipment? <h3>STUDY DESIGN/SETTING</h3> Diagnostic Study. <h3>PATIENT SAMPLE</h3> A total of 13 cadaveric specimens were used for testing to replicate a clinical setting. <h3>OUTCOME MEASURES</h3> 1) Sensitivity of CT for c-spine fracture 2) Proportion of fractures missed in CT studies with football equipment on that were deemed diagnostic by participation radiologists. <h3>METHODS</h3> A pendulum device was engineered to deliver a measured axial load to the crown of cadavers [PM1] to produce a variety of cervical spine fractures. The cadavers were then imaged using a standardized CT protocol first without and then with protective football equipment. The images were presented to three board-certified radiologists [SSL3] to identify all fractures from the occiput to T1 and assess their diagnostic quality. A sensitivity analysis was performed against a reference standard of fractures produced by the consensus of all radiologists in this study to determine if there was any reduction in radiologists' ability to detect fractures once football equipment was in place. <h3>RESULTS</h3> The radiologists in this study observed a 26.7% reduction in sensitivity for spine fracture detection once football equipment was in place (Overall, we observed a 26.7% reduction in sensitivity (51.3% (1.54/3) versus 78.0% (2.34/3), 95% CI 40.2% to 62.4%; p = 0.0032). Although the study radiologists considered 92% (72/82) of the CT images in the presence of football equipment to be of diagnostic quality, they failed to identify 51 (40.0%) total cervical spine fractures once the football equipment was introduced. <h3>CONCLUSIONS</h3> The sensitivity of cervical spine fracture detection using CT is diminished in the setting of protective football equipment. These findings contradict previous studies that determined CT to be a diagnostic imaging modality to image the cervical spine through equipment. Although the interpreting radiologists consistently deemed CTs performed in the presence of helmets and shoulder pads to have subjectively diagnostic quality, numerous fractures that had been detected in the absence of equipment were missed in their presence. The sensitivity of cervical spine fracture detection using CT is diminished in the setting of protective football equipment. Furthermore, this study established that subjective approval of the appearance of an imaging study based on the ability to recognize anatomic landmarks is insufficient to reliably determine the diagnostic quality of a CT image. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Occipital condylar avulsion fractures in the acute trauma setting: Stable or unstable injury?

Occipital condylar avulsion fractures are considered potentially unstable, associated with craniocervical dissociation spectrum injuries, and thought to carry a relatively high mortality rate based on the current literature. The purpose of this study was to identify patient with acute, occipital condylar avulsion fractures and evaluate for the incidence of concomitant cervical osteoligamentous trauma and craniocervical dissociation spectrum injury on cervical spine CT and MRI. Patients who suffered an inferomedial occipital condylar avulsion fracture were identified retrospectively using Nuance mPower software. Cervical spine CT and MRI reports performed within 48h for this patient cohort were then reviewed by two CAQ certified neuroradiologists. Confirmation of an occipital condylar avulsion fracture was recorded along with any concomitant craniocervical junction injury. Relevant clinical history, including management and outcomes, was recorded for each patient. Thirty-four patients were identified with an inferomedial fracture of the occipital condyle. Of the 85% of patients who underwent cervical MRI, all but one patient demonstrated a 'negative' MRI without major craniocervical junction ligamentous injury. These patients were treated conservatively with external bracing without persistent neurologic deficits upon 4-month follow-up. Inferomedial fractures of the occipital condyle are currently classified as potentially unstable fractures based on the Anderson classification system. Our data suggest that an isolated occipital condylar avulsion fracture without an additional C1-C2 fracture or widening of the atlanto-occipital joint space is likely a stable injury that can be treated conservatively with excellent clinical outcomes.

Obstructing Trachea Tumor: Myoepithelial Carcinoma about a Case

Myoepithelial carcinoma, also called malignant myoepithelioma, is an extremely rare tumor of the salivary gland type. It is defined as a malignant neoplasm in which the tumor cells exhibit exclusively myoepithelial differentiation. Our case is a 48-year-old patient with no specific history who was presented to the hospital emergency room for respiratory difficulty and dysphagia progressively evolving for 08 weeks. A cervical CT was done which revealed a hypodense tumor process in T1 of 4 cm long axis obstructing the trachea well limited and richly vascularized. The diagnosis of tracheal myoepithelial carcinoma was made after histological and immunohistochemical analysis on a biopsy pending analysis of the operative specimen. Treatment remains initially surgical with appropriate postoperative radiotherapy and chemotherapy.

Mapping of Venous Sinus Anatomy and Occipital Bone Thickness for Safe Screw Placement in 100 Patients with 46,200 Standardized Measurements Using Computed Tomography Angiography.

Retrospective descriptive study. The aim of this study was to create topographical maps of occipital bone thickness and venous sinus (VS) presence to assess the risks of screw insertion in four commercially available occipital plates. Craniocervical junction instability and deformity are serious pathological conditions that require posterior fixation of the occipital bone to the cervical vertebrae. Insertion of occipital bone screws requires evaluation of both occipital bone thickness for effective internal fixation and intracranial VS presence for vascular injury prevention. Despite the surgical risks, there is a paucity of research on safe screw placement. We created a matrix of 231 standardized measurement points to analyze the occipital bone thickness and VS presence in cervical spine CT angiograms. These measurements were used to create topographical maps of occipital bone thickness and likelihood of VS presence, which we then compared to the screw hole configurations of four occipital plates. Hundred patients were assessed. Maximum occipital bone thickness of 13.9 ± 3.3 mm was midline in the occipital bone, 45 mm from the foramen magnum, around the external occipital protuberance (EOP). Regions with thicknesses >8 mm were 2 cm lateral to the EOP at the level of the superior nuchal line and 2.5 cm inferior to the EOP. The area with the highest VS presence rate was around the EOP and the superior nuchal line. The right transverse VS was more prominent in both sexes. There is a limited area of the occipital bone with thicknesses for enough screw purchase. Previous studies have shown 8 mm as the minimum screw length to reduce the risk of implant failure. In our analysis, only "T"-shaped plates had configurations with thicknesses >8 mm for each screw hole. For every screw hole in the analyzed occipital plates, there was a possibility of VS presence ranging from 8% to 33%.Level of Evidence: 5.

Digital and anatomical study of posterior atlantooccipital joint-occipital condyle-clivus screw technique

Objective: To investigate the screw placement parameters, feasibility and safety of posterior atlantooccipital joint-occipital condyle-clivus screw technique in Chinese people. Methods: Upper cervical spine CT images of 46 patients, including 24 males and 22 females, were collected with random number table from June 2019 to May 2020 in Ningbo No.6 Hospital. The patients aged 20-55 years, with a mean age of (39±9) years. Total of 92 sides of upper cervical spine models were obtained by Mimics 19.0 digital three-dimensional reconstruction, and screw placement was conducted simulately. The midpoint of transition zone between the posterior arch of atlas and the inferior articular process of lateral mass was selected as the screw entry point. The diameter and length of screws was 3.5 mm and 50 mm, respectively. Detailed morphometric measurements of the 92 atlantooccipital joint-occipital condyle-clivus screws were conducted. The distance between the screw and its surrounding important structures, screw inside and upper tilting angles, the length of screw trajectory in atlas and the length of screw trajectory on occipital side (occipital condyle-clivus) were all measured. Paired t test was performed on the parameters of left and right screw placement to confirm whether there was difference between the two sides. Results: In the 46 cases of upper cervical spine digital three-dimensional models, 92 posterior atlantooccipital joint-occipital condyle-clivus screws were implanted. All the screws were completely fixed in the clivus, without breaking through the upper sphenoid sinus, entering into the canalis spinalis and foramen magnum, and damaging the surrounding structures such as hypoglossal canal. The screw trajectory parameters between the left and right sides were slightly different, but there was no statistical differences between the two sides (P>0.05). The vertical distance between the screw entry point and the upper edge of atlas was (12.6±1.0) mm, the vertical distance between the screw entry point and the lower edge of atlas was (6.5±0.6) mm, the distance between the screw and the medial border of atlas vertebral artery foramen was (6.7±0.6) mm, the distance between the screw entry point and the medial wall of atlas was (6.6±0.7) mm, the distance between the screw outer margin and the hypoglossal canal was (5.5±0.6) mm, screw inside tilting angle was 21.2°±2.5°, screw upper tilting angle was 52.0°±3.4°, the length of screw trajectory in atlas was (12.1±0.9) mm, the length of screw trajectory on occipital side (occipital condyle-clivus) was (37.9±0.9) mm. Conclusion: The posterior atlantooccipital joint-occipital condyle-clivus screw technique can serve as a feasible and safe treatment for instability of the occipitocervical junction, which can be used as a new posterior occipitocervical fusion technique.

Diagnostic of lingual tonsil hypertrophy with lateral soft tissue cervical X-ray on laryngopharyngeal reflux

Background: Lingual tonsil hypertrophy (LTH) evaluation could be performed by flexible fiberoptic laryngoscopy, lateral soft tissue cervical roentgen, CT scan, and magnetic resonance imaging (MRI).Lateral soft tissue cervical roentgen examination was considered as substitutes for diagnostic testing of LTH, which, aside from being cheaper, the examination could also be conducted in all hospitals and easy to be performed on children. Objective: To compare the lingual tonsil enlargement with examination procedure using lateral soft tissue cervical roentgen as an LTH diagnosis measure compared to the flexible fiberoptic laryngoscopy examination as the gold standard examination. Methods: A cross-sectional design study on 30 respondents of laryngopharyngeal reflux (LPR) patients whose conducted routine ENT physical examination, followed by flexible fiberoptic laryngoscopy examination along with lateral soft tissue cervical roentgen. Results: The sensitivity level of 65.38% was acquired from the statistical tests, along with specificity level of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 30.37%. Conclusions: Based on sensitivity and specificity, lateral soft tissue cervical roentgen examination could already be used as a diagnostic measure and have an accurate capability to diagnose LTH.

Subacute Cardiac Tamponade in a Patient with Malignancy

We hereby present a 57-year-old woman with a history of asthma and hypertension who presented to the emergency department with shortness of breath, syncope and loss of consciousness. Patient complained of decreased appetite, constipation and 20lbs weight loss over one month. Patient denied fever, chills, chest pain, nausea, vomiting, headache, pain or swelling in lower extremity, trauma, hemoptysis. Vitals at presentation: temperature 99.8 F, pulse 124 bpm, BP 135/93 mm Hg, respiratory rate 18 pm, oxygen saturation 96% on room air. Non-contrast CT scan of the brain was unremarkable. Cervical spine CT did not show any acute bony fracture or subluxation or central canal stenosis. Chest xray showed right upper lung infiltrate and very small right pleural effusion. Chest CT showed: small pulmonary emboli involving right lower lobe and left upper lobe sub segmental pulmonary arteries, large pericardial effusion, right upper lobe ground glass pulmonary infiltrates, right upper lobe pulmonary mass with multiple bilateral pulmonary nodules concerning for metastatic process, small right-sided pleural effusion, bilateral hilar and mediastinal lymphadenopathy concerning for metastatic disease, multiple ill-defined hepatic lesions. EKG showed sinus tachycardia without electrical alternans. Echocardiogram showed: left ventricular ejection fraction 50- 55%, grade 1 diastolic dysfunction consistent with impaired relaxation and normal filling pressures. There is a large circumferential pericardial effusion and right ventricular diastolic collapse suggesting tamponade physiology evident on echocardiogram. Pericardiocentesis was done, about 700 cc of fluid was removed and the patient’s symptoms improved. This patient had pericardial effusion most likely due to malignancy. Pericardial fluid buildup and subsequent tamponade in a malignancy is usually subacute. In malignancy, fluid accumulates slowly, pericardium stretches with time allowing ample fluid to be accumulated vs in an acute tamponade as there is very rapid, large pericardial effusion, pericardium does not have time to stretch and may present with more alarming signs and symptoms. Sub-acute tamponade as is seen in malignancy presents with less alarming signs and symptoms and might be missed. Patients with subacute tamponade may be asymptomatic or complain of fatigability, chest discomfort, dyspnea caused by decreased cardiac output and increased filling pressures.

Diagnostic Benefit of MRI for Exclusion of Ligamentous Injury in Patients with Lateral Atlantodental Interval Asymmetry at Initial Trauma CT.

Background Cervical spine CT is regularly performed to exclude cervical spine injury during the initial evaluation of trauma patients. Patients with asymmetry of the lateral atlantodental interval (LADI) often undergo subsequent MRI to rule out ligamentous injuries. The clinical relevance of an asymmetric LADI and the benefit of additional MRI remain unclear. Purpose To evaluate the diagnostic benefit of additional MRI in patients with blunt trauma who have asymmetry of the LADI and no other cervical injuries. Materials and Methods Patients who underwent cervical spine CT during initial trauma evaluation between March 2017 and August 2019 were retrospectively evaluated. Those who underwent subsequent MRI because of LADI asymmetry of 1 mm or greater with no other signs of cervical injury were identified and reevaluated by two readers blinded to clinical data and initial study reports regarding possible ligamentous injuries. Results Among 1553 patients, 146 (9%) had LADI asymmetry of 1 mm or greater. Of these, 46 patients (mean age ± standard deviation, 39 years ± 22; 28 men; median LADI asymmetry, 2.4 mm [interquartile range, 1.8-3.1 mm]) underwent supplementary MRI with no other signs of cervical injury at initial CT. Ten of the 46 patients (22%) showed cervical tenderness at clinical examination, and 36 patients (78%) were asymptomatic. In two of the 46 patients (4%), MRI revealed alar ligament injury; both of these patients showed LADI asymmetry greater than 3 mm, along with cervical tenderness at clinical examination, and underwent treatment for ligamentous injury. In 13 of the 46 patients (28%), signal intensity alterations of alar ligaments without signs of rupture were observed. Four of these 13 patients (31%) were subsequently treated for ligamentous injury despite being asymptomatic. Conclusion Subsequent MRI following CT of the cervical spine in trauma patients with lateral atlantodental interval asymmetry may have diagnostic benefit only in symptomatic patients. In asymptomatic patients without proven cervical injuries, subsequent MRI showed no diagnostic benefit and may even lead to overtreatment. © RSNA, 2021 Online supplemental material is available for this article.

CORR Insights®: Cervical Spine CT Can Miss Fractures in American Football Players When Protective Equipment is in Place: A Cadaver Study.

CORR Insights®: Cervical Spine CT Can Miss Fractures in American Football Players When Protective Equipment is in Place: A Cadaver Study.

Diagnostic Accuracy and Failure Mode Analysis of a Deep Learning Algorithm for the Detection of Cervical Spine Fractures.

Artificial intelligence decision support systems are a rapidly growing class of tools to help manage ever-increasing imaging volumes. The aim of this study was to evaluate the performance of an artificial intelligence decision support system, Aidoc, for the detection of cervical spinal fractures on noncontrast cervical spine CT scans and to conduct a failure mode analysis to identify areas of poor performance. This retrospective study included 1904 emergent noncontrast cervical spine CT scans of adult patients (60 [SD, 22] years, 50.3% men). The presence of cervical spinal fracture was determined by Aidoc and an attending neuroradiologist; discrepancies were independently adjudicated. Algorithm performance was assessed by calculation of the diagnostic accuracy, and a failure mode analysis was performed. Aidoc and the neuroradiologist's interpretation were concordant in 91.5% of cases. Aidoc correctly identified 67 of 122 fractures (54.9%) with 106 false-positive flagged studies. Diagnostic performance was calculated as the following: sensitivity, 54.9% (95% CI, 45.7%-63.9%); specificity, 94.1% (95% CI, 92.9%-95.1%); positive predictive value, 38.7% (95% CI, 33.1%-44.7%); and negative predictive value, 96.8% (95% CI, 96.2%-97.4%). Worsened performance was observed in the detection of chronic fractures; differences in diagnostic performance were not altered by study indication or patient characteristics. We observed poor diagnostic accuracy of an artificial intelligence decision support system for the detection of cervical spine fractures. Many similar algorithms have also received little or no external validation, and this study raises concerns about their generalizability, utility, and rapid pace of deployment. Further rigorous evaluations are needed to understand the weaknesses of these tools before widespread implementation.

Cervical Spine CT Can Miss Fractures in American Football Players When Protective Equipment is in Place: A Cadaver Study.

Iatrogenic worsening of spinal injury can result in significant harm to American football players and complicate management when equipment is removed in the acute setting by inexperienced personnel. Spine imaging before removal of protective equipment mitigates this risk. There is no consensus regarding the ideal timing of equipment removal or whether current diagnostic imaging modalities are effective to detect such injuries without equipment removal. Prior data suggest that CT is a diagnostic modality for this purpose; however, radiologists' accuracy in detecting fractures in the presence of protective equipment requires additional study. (1) Does the introduction of American football equipment result in a significant reduction in sensitivity for cervical spine fracture detection? (2) Absent specific guidance as to parameters needed to establish diagnostic quality, can a radiologist determine whether such CTs are of diagnostic quality by subjectively relying on the ability to identify anatomic landmarks? A pendulum device was engineered to deliver a measured axial load to the crown of cadavers to produce a variety of cervical spine fractures in 13 cadaver specimens. The cadavers were then imaged using a standardized CT protocol first without and then with protective football equipment. The images were presented to three board-certified, fellowship-trained radiologists to (1) identify all fractures from the occiput to T1 and (2) subjectively assess the diagnostic quality of the resulting CTs. A sensitivity analysis was performed against a reference standard of fractures produced by the consensus of all radiologists in this study to determine whether there was any reduction in radiologists' ability to detect fractures once football equipment was in place. We found that CT scans obtained with football protective equipment in place resulted in lower sensitivity in diagnosing cervical spine injuries than CT scans obtained without pads. A total of 42 fractures were identified in the reference standard, allowing for a combined 126 possible fracture identifications between the three interpreters. Without football equipment, a combined 98 fractures were identified, whereas a combined 65 fractures were identified once the equipment was introduced. Overall, the sensitivity was reduced by 26% (52% [65 of 126] versus 78% [98 of 126] [95% CI 14.8% to 37.5%]; p < 0.001). Of the 78 total CT series imaged with football equipment, 92% (72 of 78) were considered to be of diagnostic quality. However, the study radiologists failed to identify 50% (53 of 105) of fractures present in those CT images. The sensitivity of cervical spine fracture detection using CT is diminished in the setting of protective American football equipment. Future studies in live subjects with cervical spine fracture may be warranted to support these conclusions. These findings contradict previous studies that determined CT to be a diagnostic imaging modality to image the cervical spine through equipment. Although the interpreting radiologists consistently deemed CTs performed in the presence of helmets and shoulder pads to have subjectively diagnostic quality, numerous fractures that had been detected in the absence of equipment were missed in their presence. Furthermore, this study established that subjective approval of the appearance of an imaging study based on the ability to recognize anatomic landmarks is insufficient to reliably determine the diagnostic quality of a CT study.

Automatic clinical target volume delineation for cervical cancer in CT images using deep learning.

Accurately delineating clinical target volumes (CTV) is essential for completing radiotherapy plans but is time-consuming, labor-intensive, and prone to inter-observer variation. Automating CTV delineation has the benefits of both speeding up contouring process and improving the quality of contours. Recently, auto-segmentation approaches based on deep learning have achieved some improvements. However, unlike organ segmentation, the CTV contains potential tumor spread tissues or subclinical disease tissues, resulting in poorly defined margin interface and irregular shape. It is not reasonable to directly apply the deep learning segmentation algorithms to CTV tasks without considering the unique characteristics of shape and margin. In this work, we propose a novel automatic CTV delineation algorithm based on deep learning addressing the unique shape and margin challenges. Our deep learning method, called RA-CTVNet, segments the CTV from cervical cancer CT images. RA-CTVNet denotes our automatic CTV delineation algorithm based on deep learning with Area-aware reweight strategy and Recursive refinement strategy. (1) In order to process the whole-volume CT images and delineate all CTVs in one shot, our method is built upon the popular 3D Unet architecture. We further extend it with robust residual learning and squeeze-and-excitation blocks for better feature representation. (2) We propose area-aware reweight strategy which assigns different weights for different slices. The core is adjusting model's attention to each slice. (3) In terms of the trade-off between providing performance improvements and meeting the limitations of GPU memory, we exploit a new recursive refinement strategy to address margin challenge. This retrospective study included 462 patients diagnosed with cervical cancer who received radiotherapy from June 2017 to May 2019. Extensive experiments were conducted to evaluate performance of RA-CTVNet. First, compared to different network architectures, RA-CTVNet achieved improvements in Dice similarity coefficient (DSC). Second, we conducted ablation study. The results showed that compared to the backbone, area-aware reweight strategy increased DSC by 3.3% on average and recursive refinement strategy further increased DSC by 1.6% on average. Then, we compared our method with three human experts. Our RA-CTVNet performed better than two experts while comparably to the third expert. Finally, a multicenter evaluation was conducted to verify the accuracy and generalizability. Our findings show that deep learning is able to offer an efficient framework for automatic CTV delineation. The tailored RA-CTVNet can improve the quality of CTV contours, which has great potential for reducing the burden of experts and increasing the accuracy of delineation. In the future, if with more training data, further improvements are possible, bringing this approach closer to real clinical practice.

"Supradental space sign" on cervical spine CT-a sign of tectorial membrane injury in adults trauma patients.

The supradental space is a small, predominantly fat-filled recess superior to the atlanto-axial joint and inferior to the basion of the clivus that contains a small venous plexus. The posterior boundary of the supradental space is formed by the tectorial membrane, a stabilizing ligament of the craniocervical junction. The purpose of our study was to examine the imaging appearance of the supradental space in patients with tectorial membrane injury. Adult patients with tectorial membrane injury were identified utilizing keyword searches of radiology reports using Nuance mPower software. Age-matched positive and negative control groups were obtained. Two CAQ-certified neuroradiologists evaluated the cervical CT exams of these patients for supradental fat pad effacement from hematoma formation. The integrity of the osteoligamentous structures of the craniocervical junction was recorded on CT and MRI exams along with demographic information, clinical history, surgical management, and global outcome. Statistical analysis was performed. Sixteen adults were diagnosed with tectorial membrane injury on cervical MRI. All patients with a visible supradental space demonstrated fat pad effacement and Hounsfield units consistent with hematoma formation. The positive and negative control groups demonstrated supradental fat pad effacement in 2/16 and 1/16 patients, respectively. A p-value of < 0.001 was obtained. The "supradental space sign," defined as hematoma formation in the supradental space with effacement of the supradental fat pad is associated with tectorial membrane injury in adult trauma patients with sensitivity of 93.75% (95% confidence interval 69.77 to 99.84%) and specificity of 90.62% (95% confidence interval 74.98 to 98.02%).