Computed Tomography Scan Measurements Research Articles

Assessing the Reliability of Postoperative Cross-Table Radiographs Compared to CT Scans for Measuring Acetabular Anteversion Angle Following Total Hip Arthroplasty.

This study aimed to evaluate acetabular anteversion following total hip arthroplasty (THA) using cross-table lateral radiographs and CT scans and to determine the reliability of cross-table lateral radiographs compared to computed tomography (CT) scans for measuring acetabular anteversion. We conducted a cross-sectional study of patients undergoing THA at Justice K.S. Hegde Charitable Hospital, Deralakatte, Mangalore, from January 2020 to June 2021. Radiographs are typically taken in both anteroposterior (AP) and lateral views after THA. However, for this study, a cross-table lateral view was used instead of the usual lateral radiograph to measure the angle of anteversion. The anteversion was calculated using the method described by Woo and Morrey. Additionally, CT scans were performed on all patients as part of the study protocol. The anteversion measured in these scans was compared to that in the cross-table radiographs to assess the latter's reliability for routine use. The risk of radiation exposure from CT scans was minimized by adhering to the ALARA (As Low as Reasonably Achievable) principle, with only axial sections of the acetabular cup being scanned. The results show that the radiographic acetabular anteversion and CT scan measurements have a mean difference of 0.3036. There is a positive correlation between these measurements. The p-value is not statistically significant (p=0.698). Therefore, the measurements are correlated with each other with a linear relationship (r=0.919). For anteversion measurements using the X-ray method, the mean was 27.16 degrees with a standard deviation of ±9.49. The median was 27.26 degrees, ranging from 10.27 to 42.58 degrees. In comparison, the CT method yielded a mean anteversion of 27.40 degrees with a standard deviation of ±8.50 degrees. The median was 27.64 degrees, ranging from 12.35 to 43.11 degrees. Cross-table lateral radiographs are a reliable and comparable method to CT scans for measuring acetabular anteversion following total hip arthroplasty.

Comparative Study for Surgical Treatment of Acute Distal Tibiofibular Syndesmotic Lesions Using the Modified Suture-Button Fixation Versus Static Syndesmotic Screw Fixation.

Several techniques to treat acute distal tibiofibular instability are described consisting in static and dynamic fixation procedures. The aim of our work is to compare the outcomes of acute syndesmotic injury fixation between the modified technique of dynamic fixation using the suture-button principle as an efficient and low-cost method and the classic static fixation. It is a prospective study including patients presenting with acute syndesmotic injury. After fracture fixation, residual syndesmotic instability was managed using syndesmotic screw in group A and dynamic fixation with a double Ethibond suture in group B. Functional results were assessed using the American Orthopaedic Foot and Ankle Society score (AOFAS) score. Radiological evaluation was done by a postoperative computed tomography (CT) scan of both ankles and plain X-rays of the ankle after surgery and at 18 months. Group A included 20 patients meanwhile 35 patients were in group B. The reduction was satisfactory in the 2 groups according to the postoperative CT scan measurements. The mean healing time in group A was 49.65 days and 51.49 days in group B (P = .45). We did not find any significant difference in terms of loss of reduction in the 2 groups. The return to work was faster in group B (P = .04). Patients in group B had better AOFAS score (P = .03) and ankle range of motion than those in group A. The difference was statistically significant (P = .02 for dorsal flexion and P = .001 for plantar flexion). For group A, we did not note any early complications. Meanwhile, 7 patients developed skin complications in group B (P = .03). However, no significant difference was found in terms of late complications. The modified dynamic suture-button fixation remains a therapeutic alternative in low-income countries that could achieve better outcomes than static fixation, with easy postoperative follow-up. Level II.

Correlation between Orbital Computed Tomography Scan Measurements and Clinical Enophthalmos in Acute Isolated Orbital Floor Fractures

Abstract Purpose: To analyze the correlation between orbital computed tomography (CT) scan measurements including the fracture area (FA), the fracture location, the soft-tissue herniation volume (HV), the fractured orbital volume ratio (OVR) to the normal orbit, and the clinical enophthalmos in acute isolated orbital floor fractures. Methods: We enrolled 100 patients with acute isolated unilateral orbital floor fractures from May 2017 to January 2021. Based on the CT scan findings, we measured the FA, HV, OVR, and fracture site. We assessed enophthalmos using both clinical (CE) and radiographic (RE) measurements. Additionally, we investigated the correlation between CE and the measured parameters, along with the relationship between the pattern of diplopia and the fracture site. Results: We identified enophthalmos in 81% and diplopia in 78% of the patients with an acute blowout orbital floor fracture. CE was moderately correlated with the FA (R 2 = 0.4341, P < 0.001). CE was weakly correlated with the HV (R 2 = 0.2861, P = 0.04). Anterior fractures caused diplopia in both vertical gazes, but posterior fractures were mostly associated with diplopia in the up gaze. OVR was strongly associated with RE (R 2 = 0.663, P < 0.0001) and moderately associated with CE (R 2 = 0.4378, P < 0.0001). The univariate regression analysis also showed that OVR could significantly predict CE and RE. Conclusions: OVR surpasses other CT scan measurements such as FA and HV in the prediction of clinical enophthalmos. Thus, OVR could be utilized to estimate clinical enophthalmos at the time of presentation, especially when the acute clinical setting prohibits the proper clinical evaluation.

Calculation of body surface area of corn snakes (Pantherophis guttatus) utilizing computed tomography.

To determine the K-constant for body surface area calculation from body weight in corn snakes (Pantherophis guttatus) through the use of computed tomography (CT) measurements. 12 adult corn snakes held by North Carolina State University for research purposes underwent CT between November 2022 and January 2023. Each snake had a CT scan, physical examination, and body weight measurement. CT images were uploaded into software able to perform 3-D reconstruction and measure body surface area. The species-specific K-constant was determined using nonlinear regression analysis between body surface area and (body weight in grams)2/3. The mean body weight of the 12 adult corn snakes was 228 g, with a mean body surface area of 505.1 cm2. The calculated K-constant was 13.6 (P < .001). The resulting formula for body surface area in corn snakes is BSA in cm2 = 13.6 X (body weight in grams)2/3. The body surface area formula developed for corn snakes will allow for improved dosing accuracy for medications with low therapeutic safety margins. Additional pharmacokinetic and pharmacodynamic studies are necessary to determine the safety and efficacy of individual medications.

Abstract 181: Adiponectin Alleviates Acute Murine Pulmonary Injury Post Cardiopulmonary Resuscitation

Objective: Patients with cardiac arrest (CA) are often suffering from pulmonary ischemia-reperfusion injury after active cardiopulmonary resuscitation (CPR) and return of spontaneous circulation (ROSC). In recent years, previous studies have found that acute lung injury (ALI) after ROSC could be an independent risk factor for the prognosis of out of hospital cardiac arrest (OHCA). However, there is still a lack of effective therapy for pulmonary injury caused by CA-CPR-ROSC with no side effects. Methods: C57BL/6 male mice, aged from 8 to 10 weeks were purchased from Dossy Experimental Animals Co. Ltd (Chengdu, China). All the mice were feeding and drinking freely in the animal room of Sichuan University West China Science and Technology Park for one week. The experiments involving mice were approved by the Ethics Committee from West China Hospital of Sichuan University (approval No.2017071A). At the day before experiment, mice were given fasting treatment but allowed to drink water freely. CA-CPR-ROSC could cause global cerebral ischemia injury in vivo. APN (10μg/0.05ml per mice) was intravenously injected to mice at 10 min after restoration of spontaneous circulation (ROSC). Computed tomography (CT) scan of the lungs was performed before executing the animals. We used the Opal Color Manual IHC staining Kit for multiplex immunofluorescence staining measurement. Western blot detected the expression of Nrf2, OCLN, and CLDN5 in murine pulmonary tissues. Results: The results of CT scanning and routine histological measurements showed that APN could protect mice against murine pulmonary injury caused by CA-CPR-ROSC, compared to that of mice in CA-CPR-ROSC group. The results of western blot suggested that the expression of Nrf2 significantly increased in mice pulmonary tissues in CA-CPR-ROSC, whereas the expression of OCLN and CLDN5 obviously decreased in murine pulmonary tissues in CA-CPR-ROSC. Conclusion: Current study indicated the protect role of Adiponectin against acute murine pulmonary injury caused by CA-CPR-ROSC. The protective role of Adiponectin against acute murine pulmonary injury caused by CA-CPR-ROSC might be associated to the Nrf2 signaling pathway.

Assessment of Midline Shift in Postdecompressive Craniectomy Patients in Neurocritical Care: Comparison between Transcranial Ultrasonography and Computerized Tomography.

Monitoring and evaluation of intracranial structures remain a fundamental element in the neurointensive care unit. Most used technique to monitor progression is the use of computed tomography (CT) in intracranial hemorrhage (ICH) or stroke. Rapid assessment of brain pathology can be made using CT to analyze the midline shift (MLS), hematoma expansion, and ventricular size, but transferring a patient who is intubated is time and resource-consuming task. Ultrasonography is a noninvasive technique, portable, and has the possibility of fast interpretation. To measure the brain MLS in decompressive craniectomy patients using transcranial ultrasonography (TCS) and compare the correlation of these results with CT scan measurements of MLS in the same patient. Patients who have undergone decompressive craniectomy due to various reasons like ICH, traumatic brain injury, etc., and have a MLS. Trans cranial ultrasonography was assessed by a single consultant (Neuro Critical Care Intensivist) who was blinded for the CT scan measurement. CT scan measurement of MLS was assessed by a neuroradiologist using standard guidelines, who was blinded for the TCS results of MLS. The finding of a MLS >0.5 cm in the CT scan was considered a significant MLS. A total of 31 patients were recruited for the study. MLS measured using CT was 0.91 ± 0.67 cm. MLS via TCS was 0.91 ± 0.66 cm. A significant MLS via TCS was found in 77.4%. Intraclass correlation coefficient (ICC) was calculated between CT-MLS and TCS MLS and obtained the value of ICC as 0.996, indicating an almost perfect agreement. Patients after decompressive craniectomy may present as an ideal candidate to visualize intracerebral anatomy with a high resolution. TCS might be considered as an alternative to CT to measure MLS in decompressive craniectomy patients.

Characterization of Auricular Growth within the Pediatric Population Using Computed Tomography Scan Measurements.

In patients with microtia, auricular reconstruction is ideally performed promptly to prevent impaired socialization during formative childhood years. The earliest viable age for reconstruction is widely accepted from 7-10 years of age, as full auricular size is achieved around age 8, with some variability dependent on sex. This retrospective study aims to provide an auricular growth curve that accounts for age and sex, enhancing the individualized approach to ear reconstruction. A total of 319 images of unaffected patients who underwent computed tomography angiography of the head and neck were reviewed, with bilateral cartilage height and width measured according to a consensus-standardized image measurement protocol. Means and SDs of cartilage height and width were calculated for both sexes, and analysis of ear growth was performed through plotting the mean cartilage height, width, and width:height ratio over time. Cartilage height and width differed significantly between male and female groups. Maximum cartilage height was reached at age 11 for female and at age 12 for male patients, whereas maximum cartilage width was reached at ages 10 and 8, respectively. On average, the width:height ratio for female group was 0.58. For male group, the average width:height ratio was 0.59. An auricular growth map was designed using computed tomography measurements demonstrating maximum auricular size at age 11 and 12 respectively for female and male patients, with both sexes having a width:height ratio maintained at approximately 0.6 throughout growth.

Accuracy of 3D-Printed Models of Aortic Valves – a Comparative Analysis Between Planimetric and Photogrammetric Measurements

Abstract Background 3D printing has changed the paradigm of personalized medicine. Similarly to fingerprints, there are no two identical hearts; consequently, in cardiology, diagnosis and treatment, either medical, interventional or surgical, must be individualized according to the specific problem of a particular patient. The aim of this proof-of-concept study was to analyze two measurement methods, the planimetric and the photogrammetric method, in the process of creating a 3D-printed model from cardiac computed tomography angiography images and to evaluate the accuracy of an aortic valve anatomical model. Material and methods Cardiac computed tomography images, obtained from 20 patients with severe aortic stenosis, underwent stereolithographic reconstruction using 3D Slicer to create digital 3D models of the aortic valves. Serial measurements of six key elements of the aortic valvular apparatus were measured on the 3D model and compared to the measurements taken on the 2D computed tomography images. Results The differences between the two measurement methods were sub-millimetric in case of the left ventricular outflow tract and the sinotubular junction, and 1.386 mm for the left sinus of Valsalva (p = 0.0412), 0.3476 mm for the right sinus of Valsalva (p = 0.1874), and 0.6905 mm for the non-coronary Valsalva sinuses (p = 0.1353). Sinus heights were also similar, with a difference of 0.0119 mm (p = 0.6521). Conclusion In this study, the results of digital photogrammetry were superimposable to those of computed tomography scan measurements. The accuracy of each 3D-printed model depends on geometric complexity, the level of training of the personnel, and on the resources of each 3D printing laboratory.

Reliability and validity of the functional combined anteversion measurement method using standing lateral radiography after total hip arthroplasty.

The functional safe zone of combined anteversion (CA) shows a superior predictive value for dislocation after total hip arthroplasty (THA) compared to that of the Lewinnek safe zone. Thus, it is necessary to establish a feasible and accurate method for assessing CA for the evaluation of dislocation risk. We aimed to evaluate the reliability and validity of using standing lateral (SL) radiographs for determining CA. Sixty-seven patients who underwent SL radiography and computed tomography (CT) scans after THA were included. Radiographic CA values were obtained via the calculation of the sum of the acetabular cup and femoral stem anteversion (FSA) measurements as obtained from the SL radiographs. Acetabular cup anteversion (AA) was measured based on the tangential line to the face of the cup, whereas FSA was calculated using the developed formula based on the neck-shaft angle. The intra-observer and inter-observer reliabilities for each measurement were examined. Radiological CA values were compared with the CT scan measurements to evaluate their validity. The intra-observer and inter-observer agreements of the SL radiography were excellent [intraclass correlation coefficient (ICC) ≥0.90]. The radiographic measurements correlated well with the CT scan measurements (r=0.869, P<0.001). The mean difference between the radiographic and CT scan measurements was -0.55°±4.68° and ranged from 0.3° to 2.2° in terms of the 95% confidence interval (CI). SL radiography is a reliable and valid imaging tool for the assessment of functional CA.

Evaluation of photogrammetry for medical application in cardiology.

Background: In the field of medicine, photogrammetry has played for long time a marginal role due to the significant amount of work required that made it impractical for an extended medical use. Developments in digital photogrammetry occurred in the recent years, that have steadily increased the interest and application of this technique. The present study aims to compare photogrammetry reconstruction of heart with computed tomography (CT) as a reference. Methods: The photogrammetric reconstructions of digital images from ECG imaging derived images were performed. In particular, the ventricles of 15 patients with Brugada syndrome were reconstructed by using the free Zephyr Lite software. In order to evaluate the accuracy of the technique, measurements on the reconstructions were compared to patient-specific CT scan imported in ECG imaging software UZBCIT. Result: The results showed that digital photogrammetry in the context of ventricle reconstruction is feasible. The photogrammetric derived measurements of ventricles were not statistically different from CT scan measurements. Furthermore, the analysis showed high correlation of photogrammetry reconstructions with CT scan and a correlation coefficient close to 1. Conclusion: It is possible to reproduce digital objects by photogrammetry if the process described in this study is performed. The reconstruction of the ventricles from CT scan was very close to the values of the respective photogrammetric reconstruction.

Gender determination of scapula by computed tomography scan measurement

Gender determination of scapula by computed tomography scan measurement

BMI and Waist Circumference in Patients with Multiple Myeloma.

Context: Cancer is associated with many risk factors, including obesity. Specifically, abdominal obesity is linked to metabolic syndrome and is quantified by waist circumference (WC). Compared to WC, body mass index (BMI) is more accessible in the office to assess a patient's overall body fat composition. With preexisting computed tomography (CT) scans in multiple myeloma (MM) patients, WC can be obtained quickly and accurately as a potential prognostic biomarker. Objective: To determine if there is a correlation between BMI and WC in MM patients. Study Design and Analysis: This is a retrospective cohort study using preexisting CT scans of MM patients. Demographic information including age, sex, race, and BMI was gathered. The WC was obtained using Aquarius iNtuition software version 4.4.12. To standardize the CT scan measurements, slices were taken at the L3 vertebra with both transverse processes visible. Setting/Dataset: An academic midwestern healthcare system. Population Studied: A cohort of MM patients with CT scans. Intervention/Instrument: The scans were analyzed with Aquarius iNtuition. Outcome Measures: Average BMI and WC, as well as the correlation between BMI and WC. Results: This study includes 71 MM patients (37 women and 34 men) who had a whole-body low-dose CT scan. The average BMI was in the overweight range for both women and men at 28.7 and 28.8, respectively. Notably, the average WC was 39.4 inches for women and 41.9 inches in men, meeting one of the criteria for metabolic syndrome (>35 inches in women and >40 inches in men). BMI and WC were significantly correlated in both men and women (p <0.001). Conclusions: This is a retrospective analysis of BMI and WC in a cohort of MM patients. Traditionally, BMI has been used to quickly assess the body fat composition of patients. However, WC is a more accurate and readily accessible tool in patients with a CT scan. This measurement is strongly tied to metabolic syndrome and is part of the diagnostic criteria. We found that BMI and WC were significantly correlated in this cohort. Further follow-up is needed with a larger sample size and over a longer period. As body composition in this cohort has not been previously studied, further analyses may provide more biomarkers to aid in disease management.

Volumetric Comparison Between CT Scans and Smartphone-Based Photogrammetry in Patients Undergoing Chin Augmentation With Autologous Fat Graft.

The most accurate methods for assessing fat grafted volume, such as computed tomography (CT) scan and magnetic resonance imaging, use 3-dimensional (3D) evaluation of the recipient area. Currently, other measurement techniques such as photogrammetry (compilation of photos) are employed. The aim of the present study was to compare 3D images obtained by CT scan with those obtained by photogrammetry in patients undergoing autogenous fat grafting to the chin. A prospective longitudinal study was undertaken to assess patients undergoing autologous fat grafting to the chin, capturing preoperative and postoperative (6 months) images with CT scan and photogrammetry. Captured images were submitted to 3D reconstruction with Blender image software. A total of 40 patients were submitted to surgery. Seventy-five percent were female. Median age and BMI were 26.5 years and 23.6 kg/m2, respectively. Median volume of fat grafted was 10 mL (interquartile range 8-12.25 mL). Results showed that the median preoperative volume measured by CT scan was larger than the photogrammetry measurement (12.48 mL vs 12.01 mL, respectively, P < .001). Likewise, a larger volume was measured by CT scan than by photogrammetry (15.54 mL vs 14.94 mL respectively, P < .001) 6 months postoperatively. However, there was no difference between CT scan and photogrammetry measurements of the change in volume from preoperatively to postoperatively (P = .89). There was no agreement between fat graft volume measurements obtained by 3D photogrammetry and CT scan techniques with regard to absolute values of fat graft volume measurements, however no difference was found between the 2 methods when comparing preoperative with postoperative fat graft volume variation.

Assessment of the measurement methods in midshaft clavicle fracture

BackgroundClavicle fractures account for approximately 5% of all fractures in adults and 75% of clavicle fractures occur in the midshaft. Shortening greater than two centimeters is an indicative of surgical treatment. Radiographic exams are often used to diagnose and evaluate clavicle fractures but computed tomography (CT) scan is currently considered the best method to assess these deformities and shortening.Goal1- To investigate whether different methods of performing the radiographic exam interfere on the measurement of the fractured clavicle length.2- Compare the clavicle length measurements obtained by the different radiographic exam methods with the CT scan measurements, used as a reference.Materials and methodsTwenty-five patients with acute (< 3 weeks) midshaft clavicle fracture were evaluated. Patients underwent six radiographic images: PA Thorax (standing and lying), AP Thorax (standing and lying) and at 10° cephalic tilt (standing and lying), and the computed tomography was used as reference.ResultsThe mean length (cm) obtained were: 14,930 on CT scan, 14,860 on PA Thorax Standing, 14,955 on PA Thorax Lying, 14,896 on AP Thorax Standing, 14,960 AP Thorax Lying, 15,098 on 10° cephalic tilt Standing and 15,001 on 10° cephalic tilt Lying, (p > 0,05).Conclusion1- There is no significant statistical difference in the clavicle fracture length measurement among the variety of radiographic exam performances.2- The method that comes closest to computed tomography results is the PA thorax incidence, with the patient in the lying position.

Many hands make light work. Echocardiography and computed tomography results from the Tricuspid Regurgitation IMAging (TRIMA) study

Abstract Background Anatomic knowledge of the tricuspid valve (TV) is the first step in the diagnostic algorithm of patients with tricuspid regurgitation (TR), who are candidates for transcatheter tricuspid valve intervention (TTVI). Currently, echocardiography and computed tomography (CT) are available instruments to study the TV anatomy, guide the decision-making process and support the development of novel transcatheter therapies. Purpose The Tricuspid Regurgitation IMAging (TRIMA) study aimed to correlate CT parameters to commonly used echocardiographic variables. Methods This prospective, single-center study enrolled 22 consecutive patients with TR equal to or greater than severe (≥3+). All patients underwent transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE) and cardiac CT study, in order to obtain anatomical dimensions of the tricuspid annulus and quantification of right-chambers remodeling and function. Novel CT scan measurements were analyzed. Correlation between measurements on echocardiography and CT imaging was assessed. Results Severe TR (3+) was present in 27.4% patients, massive (4+) in 4.8% and torrential (5+) in 3.2%. The mean right ventricle (RV) length, RV mid diameter, and right atrium area were 60.81±9.11 mm, 41.27±7.67 mm and 31.72±9.66 cm2, respectively. Tricuspid annular plane excursion, fractional area change, longitudinal myocardial velocity (S') were 16.09±3.25 mm, 33.36±9.47% and 9.18±1.94 cm/sec, respectively. The annular dimensions obtained by CT scan were generally observed to reduce from diastole to systole, except for eccentricity, angles and distance between the postero-septal and antero-posterior commissure and distance between centroid and antero-posterior commissure. A Kruskal-Wallis test showed a stepwise increase in the tricuspid anatomical regurgitant orifice area (AROA) values by CT across the expanded TR grades by TEE, χ2(2)=6,466, p=0.039. Using the Pearson correlation coefficient, we found a relationship between the AROA and TR grade (r=0.593; p&amp;lt;0.004), as well as ARO-perimeter and TR grade (r=0.470; p&amp;lt;0.027). Additionally, a significant correlation was found between septal lateral annulus diameter obtained by TEE and CT (r=0.637; p=0.001). Anyway, no correlations were found between novel CT variables and TR grade or RV function assessed by echocardiogram, as well as between CT systo-diastolic annulus variability and RV function. Conclusions Standard echocardiographic study provide invaluable information about the anatomy and function of the right-chambers, as well as an accurate grade of TR. Conventional and novel variables derived by CT scan may step up the anatomical assessment of the complex morphology of the TV apparatus, thanks to the high spatial resolution of the technique. Therefore, an integrated multimodality assessment is the key point of the screening process of TR candidates for TTVI. Funding Acknowledgement Type of funding sources: None.

Postoperative Clinical and Radiological Analysis of Deviated Noses.

Anatomical deformities can greatly alter nasal function, which can be largely corrected during septoplasty and septorhinoplasty operations. In this study, we aimed to objectively measure the results of septoplasty surgeries of deviated noses with radiological analysis and compare the results with clinical evaluations. Forty patients who were undergoing septorhinoplasty were included in the study. Patients were evaluated with preoperative and postoperative paranasal computed tomography scan measurements and satisfaction surveys. Preoperative and postoperative mean ± SD septal deviation angle measurements were 11.9 ± 5.3 degrees and 6.5 ± 3.1 degrees, respectively. Preoperative and postoperative mean ± SD septal deviation distance measurements were 7.3 ± 4 and 3 ± 1.3 mm, respectively. Preoperative and postoperative mean ± SD oblique conchal measurement on the deviated side was 17.3 ± 3.2 and 13.4 ± 2.8, respectively. Preoperative and postoperative mean ± SD patient satisfaction survey scores were 17 ± 1.9 and 4.5 ± 1.9 points, respectively. To obtain a nose with a greatly improved functional gains, especially in heavy deviated noses, is an important goal in septorhinoplasty surgery. It is essential to apply the technique that will benefit the patient. The most important success criterion seems to be the regression of the clinical complaints of the patients, which can be proven objectively with computed tomography scan measurements.

Posterior Atlantoaxial Screw Placement in a Portuguese Population: A Morphometric Analysis Based on Computed Tomography Scan Measurements.

Objective The present study aims to evaluate the screw length and trajectory angles for posterior atlantoaxial fixation in a Portuguese population, through the study of cervical computed tomography (CT) scans. Methods Cervical CT scans of 50 adults were measured according to predefined screw trajectories of C1-C2 transarticular (C1C2TA), C1 lateral mass (C1LM), C2 pedicle (C2P), C2 pars and C2 laminar (C2L) screws. For each of these trajectories, screw length and angles were measured and compared between males and females. Results For the C1C2TA screw trajectory, the mean length, medial, and cranial angles were 34.12 ± 3.19 mm, 6.24° ± 3.06, and 59.25° ± 5.68, respectively, and for the C1LM screw trajectory, they were 27.12 ± 2.15 mm, 15.82° ± 5.07, and 13.53° ± 4.80, respectively. The mean length, medial, and cranial angles for the C2P screw trajectory were 23.44 ± 2.49 mm, 27.40° ± 4.88, and 30.41° ± 7.27, respectively; and for the C2 pars screw trajectory, they were 16.84 ± 2.08 mm, 20.09° ± 6.83, and 47.53° ± 6,97. The mean length, lateral, and cranial angles for the C2L screw trajectory were 29.10 ± 2.48 mm, 49.80° ± 4.71, and 21.56° ± 7.76, respectively. There were no gender differences except for the lengths of the C1C2TA ( p = 0,020) and C2L ( p = 0,001) screws, which were greater in males than in females. Conclusion The present study provides anatomical references for the posterior atlantoaxial fixation in a Portuguese population. These detailed data are essential to aid spine surgeons to achieve safe and effective screw placement.

Computed tomography scan measurements of the globe and orbit to assess the risks of traumatic complications from medial peribulbar anaesthesia

Complications of peribulbar anaesthesia include retrobulbar haemorrhage, globe perforation and brainstem anaesthesia. Therefore, this study took measurements relating the proximity of medial canthus to the optic nerve and also the safe angle between orbit and globe using 200 multiplanar reconstructed computed tomography (CT) images of the orbit. The principal results show that in 1.5% of the sample, the optic nerve is within 20 mm of the medial canthus, with a minimum distance of 15 mm. One% have a safe angle of 10 degrees or less between bone and globe. None of the demographic data, nor axial length were predictive of these results. We have shown that there are a minority of patients with unusual orbital anatomy. This places them at a theoretical higher risk of complications. These cases are not currently predicted by measured data.

Comparison of Dorsal-to-Ventral Ratios of the Cervical Paraspinal Musculature in French Bulldogs With and Without Cervical Intervertebral Disk Disease and Two Other Breeds Based on CT Scan Measurements

Objective: To objectively assess the cervical paraspinal musculature of French bulldogs (FBs) using computed tomography (CT) scan-based measurements, outline differences in other breeds published in the literature, and investigate the potential influence of its cervical paraspinal musculature on predisposed sites for intervertebral disk disease.Animals: Thirty FBs that underwent CT scans of the cervical spine from the skull to C7/T1 were enrolled. Fifteen dogs were patients suffering from intervertebral disk herniation (IVDH group), and 15 dogs underwent CT scans due to brachycephalic obstructive airway syndrome (BOAS group).Methods: At the level of each cervical intervertebral disk from C2/C3 to C7/T1, measurements were performed and statistically analyzed. On the sagittal CT scan reconstruction, the height ratio of the dorsal to ventral paraspinal musculature and the angle of the disk axis to vertebral body length were assessed. On the transverse plane, the area ratio of the dorsal and ventral paraspinal musculature and the ratio of force moments were determined at each intervertebral disk level. Finally, ratios were compared to the values of Labrador retrievers and dachshunds published by Hartmann et al. (1).Results: Comparing the two FB groups, one significant difference was detected in the mean height ratio of the dorsal to ventral paraspinal musculature at the level of C5/C6 (P = 0.0092) and C6/C7 (P = 0.0076), with IVDH FBs having the more prominent dorsal paraspinal musculature. At the level of C3/C4, a significantly less prominent dorsal paraspinal musculature in FBs than in dachshunds (P = 0.0058) and a significantly steeper disk to vertebral body angulation were observed (P = 0.0005).Conclusion: Although some incidental differences were found, most parameters did not significantly differ between the BOAS and IVDH FBs. Significant conformational differences in the cervical paraspinal musculature and disk to vertebral body length angulation were found between FBs and two other breeds (chondrodystrophic and non-chondrodystrophic). This study's findings suggest that the paraspinal musculature is an additional biomechanical influencing factor on the preferential sites of IVDH in the cervical spine and that other major factors exist in IVDH development, especially in FBs.

Ultrasound for Assessment and Follow-up of Airway Stenosis

BackgroundUltrasound is a reliable tool for airway assessment and management. We evaluated the accuracy of ultrasound in the preprocedure planning and follow-up evaluation of patients undergoing airway stenting for benign upper airway stenosis. MethodsThis was a retrospective single center study on patients with benign upper airway stenosis treated with airway stenting. Ultrasound evaluated the characteristics of the stenosis (distance from vocal folds, diameter, and length) before treatment and any complications after treatment; these results were then statistically compared with those obtained by computed tomography, taking the endoscopy as the reference method. ResultsTwenty-seven patients were evaluated. Ultrasound was significantly correlated with endoscopy and computed tomography scan measurements as distance of stenosis from vocal folds (r = 0.88; P < .001 and r = 0.87; P < .001, respectively), diameter of the stenosis (r = 0.97; P < .001 and r = 0.97; P < .001, respectively), and length of the stenosis (r = 0.97; P < .001 and r = 0.97; P < .001, respectively). Four out of 27 (15%) patients presented complications after treatment as stent migration (n = 2; 7%); stent obstruction (n = 1; 4%), and granulation of vocal fold (n = 1; 4%). All complications but granulation of vocal fold were correctly depicted by ultrasound and computed tomography without significant difference in comparison to endoscopy (P = .87) ConclusionsUltrasound is a promising tool in assessment of airway stenosis and follow-up of patients after stenting; it may be routinely used in adjunction to computed tomography and/or endoscopy in this setting, if our results are corroborated by a future larger study.