Axial Computed Tomography Scans Research Articles

Can acetabular dysplasia be measured on axial CT? A measurement for trauma surgeons

BackgroundAcetabular dysplasia has been theorized as a risk factor instability amongst common acetabular fractures, such as posterior wall (PW) fractures. However, common radiographic measurements often cannot be acquired in trauma patients. We evaluated axial computed tomography (CT) scans to identify novel, easily-obtained measurements that correlate with acetabular dysplasia for use in surgical indications and planning. MethodsPatients with known acetabular dysplasia undergoing elective periacetabular osteotomy were selected. A different group of patients without pelvic ring or acetabular fractures from an institutional trauma registry were selected as a comparison group. Standard indices of dysplasia were collected, such as center-edge angle (CEA). Acetabular geometric measurements were taken at three axial levels: 0 – cranial CT slice at the dome; 1 – cranial CT where the dome is an incomplete circle; 2 – cranial CT with femoral head visible. Distances between levels were also calculated: Levels 0–1 (Dome Height; DH), Levels 1–2 (Head Height; HH), and Dome-Head Difference (DH – HH = DHD). ResultsDH, HH, and DHD were all significantly correlated with CEA, Tonnis angle, and Sharp's angle in dysplastic hips. All dysplastic hips had DH ≤ 2.5 mm and HH ≥ 1.25 mm. DHD ≤ 0 mm was most specific (93.6 % sensitive, 77.3 % specific) for predicting dysplasia. ConclusionDH ≤ 2.5 mm, HH ≥ 1.25 mm, and DHD ≤ 0 mm were independently associated with dysplasia on axial CT scans. These measurements may be quickly and easily used by trauma surgeons to assess a trauma-based axial CT scan for acetabular dysplasia.

Objective Parameters for Evaluating Internal Nasal Valve Compromise: Beyond the Angle Perspective.

Nasal valve surgery for internal nasal valve (INV) compromise has become increasingly popular. However, this rise in popularity has sparked debates regarding its indications and disputes over insurance coverage, primarily due to the lack of a gold-standard evaluation method. Therefore, we aimed to identify objective parameters for the INV compromise. We analyzed 186 INVs in 93 patients who underwent nasal valve surgery. The data comprised facial computed tomography (CT) images, acoustic rhinometry, the modified Cottle test, and symptom scores. Patients were categorized based on their symptoms and the. of the modified Cottle test. We measured the INV angle, area, volume, lateral wall thickness, septal angle, and nasal bone area using CT. The compromised INV group, characterized by nasal obstruction with a positive modified Cottle test, exhibited smaller INV areas in both coronal and axial views, reduced INV volume in the axial view, and a thinner lateral wall in the coronal view (all P<0.05). Acoustic rhinometry indicated a smaller minimal cross-sectional area and volume in the compromised INV group (both P<0.001). Regression analysis demonstrated significant associations between a compromised INV and reduced INV area on the axial view, as well as the minimal cross-sectional area measured by acoustic rhinometry. Relying solely on the INV angle in CT scans has limitations in assessing compromised INV. Alternatively, the INV area on axial CT scans and the minimal cross-sectional area measured by acoustic rhinometry may serve as objective parameters for evaluating INV compromise.

Side specific differences of Hounsfield-Units in the osteoporotic lumbar spine.

Gold standard for determining bone density as a surrogate parameter of bone quality is measurement of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA), most commonly performed on the lumbar spine (L1-L4). Computed tomography (CT) data are often available for surgical planning prior to spine procedures, but currently this information is not standardized for bone quality assessment. Besides, measuring the Hounsfield-Units (HU) is also of great importance in the context of biomechanical studies. This in vitro study aims in comparing BMD from DXA and HU based on diagnostic CT scans. In addition, methods are presented to quantify local density variations within bones. One hundred and seventy-six vertebrae (L1-L4) from 44 body donors (age 84.0±8.7 years) were studied. DXA measurements were obtained on the complete vertebrae to determine BMD, as well as axial CT scans with a slice thickness of 1 mm. Using Mimics Innovation Suite image processing software (Materialise NV, Leuven, Belgium), two volumes (whole vertebra vs. spongious bone) were formed for each vertebra, which in turn were divided in their left and right sides. From these total of six volumes, the respective mean HU was determined. HU of the whole vertebra and just spongious HU were compared with the BMD of the corresponding vertebrae. Side specific differences were calculated as relative values. Whole bone and spongious HU correlated significantly (P>0.001; α=0.01) with BMD. A positive linear correlation was found, which was more pronounced for whole bone HU (R=0.72) than for spongious HU (R=0.62). When comparing the left and right sides within each vertebra, the HU was found to be 10% larger on average on one side compared to the opposite side. In some cases, the difference of left and right spongious bone can be up to 170%. There is a tendency for the side comparison to be larger for the spongious HU than for the whole vertebra. Determination of HU from clinical CT scans is an important tool for assessing bone quality, primarily by including the cortical portion in the calculation of HU. Unlike BMD, HU can be used to distinguish precisely between individual regions. Some of the very large side-specific gradients of the HU indicate an enormous application potential for preoperative patient-specific planning.

Retromalleolar groove morphology of the tibialis posterior tendon (TPT) in patients without TPT pathology evaluated by axial computed tomography scans

BackgroundThis study aimed to evaluate the shape of the retromalleolar groove of the tibialis posterior tendon (TPT) using computed tomography (CT). MethodsCT images of patients with foot or ankle pathologies were retrospectively reviewed. The morphology of the retromalleolar groove of the TPT was assessed at two different levels: the ankle joint and 10 mm above the ankle joint. The groove shape was classified into three types; concave, flat, or irregular. In cases with concave grooves, the width and depth of the grooves were measured. ResultsOf the 116 ankles from 116 subjects included in this study, 80.2 % showed a shallow concave shape (mean depth, 1.6 mm) at the two scan levels. The shape and width of the groove differed significantly by gender, although there was no significant difference in the groove depth. ConclusionApproximately 80% showed a shallow concave groove of the TPT. The groove characteristics differed by gender, although there was no significant difference in the groove depth. Level of evidenceCross-sectional cohort study; Level of evidence, Ⅳ

Atlantooccipital assimilation associated with combined atlas arch defect: a radiological case report.

In this report, atlantooccipital assimilation (AS), anterior arch defect (AAD), and posterior arch defect (PAD) of the atlas, and several variations around the craniocervical junction were identified on computed tomography (CT) of a patient of unknown sex and age. Coronal and sagittal CT scans showed AS and bilateral fusion of the atlas and the base of occipital bone. Axial CT scan at the atlas revealed PAD type B on the left side and midline AAD. Morphometric measurements indicated a potential ventral spinal cord compression. In addition, mid-sagittal CT revealed the presence of fossa navicularis magna and incomplete formation of the transverse foramen on the right side. This study reports an extremely rare AS associated with AAD, PAD, and other variations of the clivus and the atlas. To our knowledge, no similar case has been reported in the literature.

Early Clinical and Radiologic Evaluation of Unilateral Biportal Endoscopic Unilateral Laminotomy and Bilateral Decompression in Degenerative Lumbar Spinal Stenosis: A Retrospective Study.

The aim of this study is to evaluate the changes in radiologic parameters and clinical outcomes following unilateral biportal endoscopic unilateral laminotomy and bilateral decompression (UBE ULBD) for treatment of central lumbar spinal stenosis. Forty-one central lumbar spinal stenosis patients who underwent UBE ULBD were enrolled from April 2021 to February 2023. Visual analog scale (VAS) for back pain and leg pain, Oswestry Disability Index (ODI) score, and the modified MacNab criteria were assessed preoperatively and postoperatively. The preoperative and postoperative cross-sectional area of the spinal canal (CSAC), anteroposterior diameter, horizontal width, and ipsilateral and contralateral lateral recess height were calculated from axial computed tomography (CT) scans. Percentage of facet joint preservation measured on axial CT scans was obtained preoperation and postoperation. The VAS for back and leg pain improved from 7.24 ± 0.80 and 7.59 ± 0.59 preoperatively to 2.41 ± 0.55 and 2.37 ± 0.62 (p < 0.05) postoperatively and 1.37 ± 0.54 and 1.51 ± 0.55 at the last follow-up (p < 0.05). For ODI, improvement from 60.37 ± 4.44 preoperatively to 18.90 ± 4.66 (p < 0.05) at the last follow-up was observed. CT scans demonstrated that the postoperative CSAC increased significantly from 287.84 ± 87.81 to 232.97 ± 88.42 mm (p < 0.05). The mean postoperative anteroposterior diameter and horizontal width increased significantly from 18.01 ± 3.13 and 19.57 ± 3.80 to 22.19 ± 4.56 and 21.04 ± 3.72 mm, respectively (p < 0.05). The ipsilateral lateral recess height and contralateral lateral recess height were 3.39 ± 1.12 and 3.20 ± 1.14 mm preoperatively and 4.03 ± 1.37 and 3.83 ± 1.32 mm (p < 0.05) postoperatively, with significant differences. The ipsilateral and contralateral facet joint preservations were 88.17 and 93.18%, respectively. The UBE ULBD surgery is a safe and effective treatment for central lumbar spinal stenosis, associated with significant improvement in clinical outcomes and radiologic parameters. Studies with larger samples and longer follow-up periods are needed for further research.

Collateral after Splenic Vein Thrombosis

A 46-year-old man presented to the emergency department because of relapsing abdominal pain in the left abdominal quadrants. At admission, he was in good general condition and his vital signs were normal. The only abnormal laboratory findings were a C-reactive protein of 30 mg/L and thrombocytes of 127 G/L. An abdominal computed tomography (CT) scan showed a thrombosis of the distal splenic vein (panel A, double arrow) with the presence of a superior and an inferior spleno-mesenteric collateral (panel A, asterisks). The axial CT scan (panel V, arrows) and Doppler sonography (panel C) showed that the thick collaterals developed below the abdominal wall. A gastroscopy showed stage I fundic varices, but no esophageal varices. (1-10) This patient was diagnosed with a smoldering multiple myeloma 5 years earlier with regular follow-up in the hemato-oncology department. No other pro-thrombotic conditions were found and in a follow-up CT scan 6 months later the findings were un-changed despite anticoagulation. Splenic vein thrombosis is frequently diagnosed in the chronic stage, when collaterals have already developed (11-18). In this case, the presence of two major spontaneous shunts between the splenic vein and the superior mesenteric vein is preventing complications (19-23) such as porto-systemic encephalopathy and variceal bleeding

Discrepancies in Splenic Size Measurement: A Comparative Analysis of Ultrasound and Computed Tomography.

The accurate measurement of splenic size is essential for the diagnosis and management of various gastrointestinal and hematological conditions. While ultrasound (US) and computed tomography (CT) are widely used imaging modalities for assessing splenic size, discrepancies between their measurements have been observed in clinical practice. This study aimed to analyze the measurement differences between US and CT and identify factors influencing these differences. A retrospective analysis of 598 asymptomatic patients who underwent both abdominal US and CT was conducted. Measurements of splenic size obtained from US, axial CT, and coronal CT scans were compared, and various factors such as patient demographics, operator experience, and imaging parameters were evaluated to elucidate their impact on the measurement discrepancies. The results revealed that US consistently underestimated splenic size compared to CT. The magnitude of the discrepancy was influenced by factors such as patient age, body mass index (BMI), depth of the spleen from skin on US and that on CT, visibility of the splenic hilum on US, sonic window quality, and operator experience. This study underscores the importance of considering these factors when interpreting splenic measurements obtained from different imaging modalities in clinical practice.

An assessment of the clinical relevance of coracoid graft osteolysis following the Latarjet procedure: a clinical and radiological review

The Latarjet procedure was developed for the treatment of anterior shoulder instability in young, high-demand patients with attritional glenoid bone loss, whose risk of redislocation following primary dislocation may exceed 90%. Coracoid graft osteolysis and prominent screws are commonly observed in late computed tomography (CT) scans of patients who re-present following the procedure, but the clinical relevance of osteolysis in the overall Latarjet cohort is undetermined. We aimed to evaluate clinical and radiological outcomes in patients who underwent the Latarjet procedure, and to determine if severe coracoid graft osteolysis compromised clinical outcomes. This was a retrospective analysis of patients who underwent the open Latarjet procedure. Patients were invited via an e-questionnaire that contained a Western Ontario Shoulder Instability Index (WOSI), and queried about redislocation and reoperation since index surgery. Preoperative glenoid bone loss was calculated on CT using the best-fit circle method. Osteolysis was graded (0, screw head buried in graft; 1, screw head exposed; 2, threads exposed; 3, complete resorption/severe osteolysis) at the level of the proximal and distal screws respectively, on axial CT scans performed ≥ 12 months postoperatively. Between 2011 and 2022, a single surgeon performed 442 Latarjet procedures. One hundred fifty eight patients responded to the questionnaire at median (interquartile range [IQR]) 44 (27-70) months postoperatively, among whom the median (IQR) WOSI score was 352 (142-666) points (0=best, 2100=worst). Recurrent anterior instability occurred in 3/158 (2%) patients. One patient required reoperation for this indication. Among patients who had CT scans ≥ 12 months postoperatively (median [IQR] 40 [29-69] months), 1 patient developed severe osteolysis around both screws (WOSI=90), 17/62 (27%) patients developed severe osteolysis around 1 screw, all of which were proximal (median [IQR] WOSI=235 [135-644]), and 44/62 (71%) patients did not develop severe osteolysis around either screw (median [IQR] WOSI=487 [177-815]). There were no statistically significant differences in WOSI scores between groups based on the presence of severe osteolysis. The Latarjet is reliable procedure that has a low rate of redislocation and reoperation. Severe coracoid graft osteolysis occurs with time, and always affects the proximal graft first. The presence of severe osteolysis did not compromise clinical outcomes.

Frequency of brain ventricular enlargement among patients with diabetes mellitus

AimsTo determine the prevalence of dilated ventricles and concomitant high blood glucose measures. MethodsWe retrieved blood glucose measures from the emergency department database and selected a subgroup of individuals having both the radiological marker Evans’ index (EI) values and blood glucose measures. ResultsOut of 1221 consecutive patients submitted to axial Computed Tomography scans, a blood glucose measure was detected in 841 individuals. 176 scans (21 %) showed an EI > 0.30. According to the blood glucose categorization, diabetic patients were 104 (12 %), 25 of them (24 %) were dilated (mean EI 0.33). The age difference between dilated and not-dilated ventricles is about ten years in not-diabetic participants, whereas it is five years in diabetic participants. The age difference between dilated and not-dilated ventricles is about 10 years in diabetic men, whereas it zero in diabetic women. ConclusionsPathological ventricular enlargement is more frequent in men and in the elderly. In diabetic patients (especially women), the cerebral ventricles enlarge faster than in non-diabetic individuals. Age, sex, and diabetes may interact in determining how cerebral ventricle size changes over time, especially in diabetic women, making routine brain imaging advisable in these patients after the age of 70 years.

Differences in Retromalleolar Fibular Groove Morphology According to Level of Axial Computed Tomography Scans.

Studies have evaluated types of retromalleolar groove using axial magnetic resonance imaging at the level of 10 mm above the tip of the lateral malleolus. However, no evidence is available to support that this level is appropriate for evaluating retromalleolar groove morphology. To assess the influence of the level of axial computed tomography (CT) scans on the assessment of retromalleolar groove morphology. Cross-sectional study; Level of evidence, 3. The study population included 122 patients (mean age, 27.9 ± 11.8 years; 69 males, 53 female) who underwent CT scans to evaluate foot or ankle pathologies between 2020 and 2023. The shape of the retromalleolar groove (concave, flat, convex, or irregular) at 3 levels of axial CT scans (8, 10, and 12 mm above the tip of the lateral malleolus) was assessed independently by 2 orthopaedic surgeons. The length from the tip of the lateral malleolus to the proximal tip of the fossa of the lateral malleolus was also measured on coronal CT scans. The type of retromalleolar groove was significantly different according to the level of CT scans (8 vs 10 mm, P = .0001; 10 vs 12 mm, P = .0001; 8 vs 12 mm, P = .001). The type of retromalleolar groove was the same at all 3 levels in 31.1% of patients (38/122). The length from the tip of the lateral malleolus to the proximal tip of the fossa of the lateral malleolus was <10 mm in 17.2% of patients (21/122). The shape of the retromalleolar fibular groove was affected by the level at which the CT scan was obtained. Approximately 70% of the patients showed different types of retromalleolar grooves among the 3 CT scan levels.

Evaluation of Zygomaticomaxillary Complex Fractures with Gillies Approach in Al-Baha Region of Saudi Arabia: A Cohort Study.

The aim of this study was to evaluate the accuracy of the degree of fracture reduction after open reduction and internal fixation of Zygomaticomaxillary Complex (ZMC) fractures in the Saudi population of the Al-Baha region, using Gillies approach. Further comparison with preoperative and postoperative standardized computed tomography (CT) views with the calculation of residual deformity percentage, which remained after the ZMC rehabilitation. A 5-year retrospective CT-based study on preoperative and postoperative axial CT scans of 46 male patients with ZMC fractures. The CT measurements were made (in millimeters) at the fracture site of maximum displacement through the anterior orbital rim and orbital floor, posterolateral wall of the maxillary sinus, zygomatic arch, and zygomaticofrontal suture. For the zygomatic arch, measurements were made (in mm) by drawing a tangent to the fractured arch segments and dropping a perpendicular to the inward displaced fractured arch. The total difference in all measured parts between preoperative and postoperative displacement was calculated in percentages. Upon comparison of preoperative and postoperative zygomaticomaxillary complex CTs, three-point fixation at the regions of infraorbital rim, frontozygomatic suture, and posterolateral wall of the maxilla results in a reduction of the fracture sites in the range of 72.85% to 85%. Maximum reduction was noted at the zygomatic arch, that is, 85%, and minimum at the infraorbital rim, that is, 72.85%. The reduction obtained at all four sites was statistically significant, with P values ranging from .011 to .039. Gillies temporal approach and three-point fixation at the regions of the infraorbital rim, frontozygomatic suture, and posterolateral wall of the maxilla results in satisfactory treatment of ZMC fractures and improves patients oral health and quality of life.

Morphological Evaluation of Lumbar Facet Joints in Professional Baseball Players.

Many professional baseball players experience low back pain, a major cause of which is lumbar facet joint arthropathy. To evaluate the relationship between the dominant hand side and facet joint morphology in baseball movement. Cross-sectional study; Level of evidence, 3. Participants were 25 Japanese professional baseball players (11 pitchers and 14 fielders) with low back pain and lower limb symptoms. Player age, hand dominance, and length of professional playing experience were recorded, and the lateral diameter of all lumbar facet joints was determined from the axial computed tomography scans. We defined the facet joints ipsilateral and contralateral to the dominant hand as dominant and nondominant, respectively. The nondominant-to-dominant (N/D) ratio of the lateral diameter was calculated, and differences between the pitchers and fielders were analyzed using the unpaired t test. The average player age and length of professional playing experience were 26.9 years (range, 19-37 years) and 7.2 years (range, 1-15 years), respectively. The right hand was dominant in 9 pitchers and 5 fielders, while the left hand was dominant in 2 pitchers and 9 fielders. In pitchers, the average lateral facet joint diameter on the nondominant side was significantly larger than on the dominant side at all vertebral levels except L1 to L2 (P < .05 for all). The N/D ratio for each facet joint was 1.06 (L1-L2), 1.11 (L2-L3), 1.10 (L3-L4), 1.12 (L4-L5), and 1.12 (L5-S1). In fielders, the average lateral facet joint diameter on the dominant side was significantly larger than on the nondominant side at L3 to L4 (P < .05), with N/D ratios of 0.98 (L1-L2), 0.96 (L2-L3), 0.94 (L3-L4), 0.97 (L4-L5), and 0.98 (L5-S1). The N/D ratio was significantly larger in pitchers than in fielders at all levels (P < .05 for all). The facet joints of professional baseball players were enlarged asymmetrically, with different tendencies observed between pitchers and fielders. Although pitching and batting are movements that transmit the rotation from the lower limbs to the upper limbs, the effects of rotation and lateral flexion were associated significantly with facet joint hypertrophy.

Development of a Deep-Learning Model for Diagnosing Lumbar Spinal Stenosis Based on CT Images.

Retrospective study. This study aimed to develop an initial deep-learning (DL) model based on computerized tomography (CT) scans for diagnosing lumbar spinal stenosis. Magnetic resonance imaging is commonly used for diagnosing lumbar spinal stenosis due to its high soft tissue resolution, but CT is more portable, cost-effective, and has wider regional coverage. Using DL models to improve the accuracy of CT diagnosis can effectively reduce missed diagnoses and misdiagnoses in clinical practice. Axial lumbar spine CT scans obtained between March 2022 and September 2023 were included. The data set was divided into a training set (62.3%), a validation set (22.9%), and a control set (14.8%). All data were labeled by two spine surgeons using the widely accepted grading system for lumbar spinal stenosis. The training and validation sets were used to annotate the regions of interest by the two spine surgeons. First, a region of interest detection model and a convolutional neural network classifier were trained using the training set. After training, the model was preliminarily evaluated using a validation set. Finally, the performance of the DL model was evaluated on the control set, and a comparison was made between the model and the classification performance of specialists with varying levels of experience. The central stenosis grading accuracies of DL Model Version 1 and DL Model Version 2 were 88% and 83%, respectively. The lateral recess grading accuracies of DL Model Version 1 and DL Model Version 2 were 75% and 71%, respectively. Our preliminarily developed DL system for assessing the degree of lumbar spinal stenosis in CT, including the central canal and lateral recess, has shown similar accuracy to experienced specialist physicians. This holds great value for further development and clinical application.

Percutaneous Cryoablation of Recurrent or Oligometastatic Tumors in Thoracoabdominal Soft Tissues: Safety, Effectiveness, and Technical Aspects

PurposeTo assess the effectiveness and safety of cryoablation (CRA) for the treatment of recurrent or oligometastatic solid tumors located in the thoracoabdominal soft tissues. Materials and MethodsTwenty-two percutaneous CRA procedures performed in 19 patients to treat recurrent or oligometastatic tumors in thoracoabdominal soft tissue were retrospectively examined. All procedures were performed between January 2015 and June 2021 under ultrasound and computed tomography (CT) guidance, and the most complex procedures were performed with CT-based navigation systems. The histology of the primary tumors included colorectal adenocarcinoma, squamous cell lung carcinoma, pancreatic adenocarcinoma, renal cell carcinoma, and hepatocellular carcinoma. Adverse events, technical success, and local tumor control were analyzed. ResultsThe mean age of the patients was 66.5 years, with a mean tumor size of 24.8 mm. The mean time of the procedures was 68 minutes, with a mean number of 2.5 cryoprobes used. Hydrodissection was performed in 63% of the procedures to protect the surrounding anatomical structures. The mean size of the ice ball, measured on axial CT scans at the end of the procedures, was 43.5 mm. No severe adverse events were observed. Technical success was achieved in all cases. Three patients experienced local tumor progression (2 residual disease and 1 recurrence), which were successfully treated with a second CRA procedure. ConclusionsPercutaneous CRA is a safe and effective therapy in selected cases of recurrent or oligometastatic tumors in the thoracoabdominal soft tissues.

Physiologic Osseous Remodeling of the Anterior Wall of the Spinal Canal after Anterior Cervical Corpectomy and Fusion: A Retrospective Observational Study.

Anterior cervical corpectomy and fusion (ACCF) has been widely used in the treatment of cervical spondylotic myelopathy (CSM), ossification of posterior longitudinal ligament (OPLL), cervical trauma, and other cervical diseases, but few studies have reported the osseous and physiologic remodeling of the anterior wall of the spinal canal following ACCF. In this study, we analyze that remodeling process and its influence on titanium mesh cage (TMC) subsidence. We performed a clinical and radiologic analysis of consecutive patients treated with ACCF. Growth rates (GRs) reflecting the extent of remodeling of the remnants of the resected vertebral bodies were measured. We compared the computed tomography (CT) scans taken immediately and at least 1 year after surgery, and a literature review was conducted. In all, 48 patients underwent ACCF at a mean age of 61.5 ± 12.0 years. The median follow-up was 36 months, and 159 CT images were analyzed. The GR values of the remnants of the vertebral bodies on CT images immediately and 1 year after surgery were 0.505 ± 0.077 and 0.650 ± 0.022 (p < 0.001), respectively, and the GR value at ≥4 years was 1. Axial CT scans showed that remodeling starts from the lateral remnants of the resected vertebral bodies, finally reaching the center. When fusion of the vertebral bodies and the titanium cage was complete during the first year after ACCF, osteogenesis and remodeling were initiated in the osseous anterior wall of the spinal canal. The remodeling of the osseous anterior wall of the spinal canal was completed at the fourth year after surgery, without recompressing the spinal cord, as seen on both axial and lateral CT scans. According to the literature review, there was no TMC subsidence at more than 4 years after surgery. The anterior wall of the spinal canal undergoes osseous remodeling after ACCF. The process is complete in the fourth year after surgery and prevents TMC subsidence.

Delineation of Lingual Artery as an Additional Organ-At-Risk for Stereotactic Body Radiation Therapy of Head and Neck Cancers

Lingual artery (LA) stenosis or bleeding can be a potentially fatal consequence of stereotactic body radiation therapy of recurrent head and neck cancer. We aim to provide delineation guidelines for LA contouring during head and neck radiation. Three experienced radiation oncologists and 1 radiologist studied the course of LA and its anatomic relationships. A step-by-step guideline was formulated for its delineation on contrast-enhanced axial computed tomography scans. We recommend that LA should be considered an important organ at risk for stereotactic body radiation therapy of head and neck cancer. Its delineation and dose constraints should be considered on a case-to-case basis.

Combining radiographic and CT measurements to rival MRI for the diagnosis of acute isolated syndesmotic injury.

Acute isolated syndesmotic injuries (AISIs) have a high potential to be misdiagnosed or underdiagnosed at initial presentation to the hospital. Although magnetic resonance imaging (MRI) is the gold standard in noninvasive diagnostics, it is not always available immediately and is much more expensive than other imaging modalities. This study identifies improvements in conventional radiography and computed tomography (CT) to diagnose AISI and aims to reduce the number of MRI scans needed to verify the diagnosis. A retrospective case match control study was conducted by searching our trauma database between 2008 and 2022. A study group of patients with AISI (n = 64) and a control group of patients without AISI (n = 76) were formed to generate an equal number of images from both groups (62 radiographs and 22 CT scans). A total of 16 parameters that quantify the distal tibiofibular relation in injured and uninjured ankles were analyzed. For statistical analysis, a two-sided t-test was applied to calculate significant differences (p < 0.05). In a further step, a receiver operating characteristic curve (ROC) was used to determine cut-off values for the most significant parameters. The most significant measurement (p < 0.001) on axial CT scans was the syndesmotic area (SA). The ROC curve revealed an area under the curve (AUC) of 0.94 (95% CI 0.86-1.0) and a cut-off value of 71.68 mm2 that shows a sensitivity and specificity of 95.5% and 81.8%, respectively. This study suggests that radiographic imaging could represent an equally accurate alternative to MRI. These methods might generate the correct diagnosis faster due to their availability and inexpensiveness. By applying our new cut-off values in a clinical setting, the number of underdiagnosed and untreated unstable syndesmotic injuries could be reduced. III, retrospective comparative study.

Optic Nerve Ischemia Secondary to Pediatric Orbital Cellulitis.

FIG. 1FIG. 2Diffusion-weighted imaging (DWI) is a specific sequence of magnetic resonance imaging (MRI) that estimates the rate of water diffusion. The apparent diffusion coefficient (ADC) image, on its turn, is a form of quantifying the diffusion of water in DWI. Obstacles to water diffusion include cellularity and ischemia, which are seen with high signal intensity in DWI and low signal intensity in ADC. We describe the case of an 11-year-old boy who presented with left rapid-evolving cellulitis and globe tenting (Fig. 1A, massive left hemifacial and eyelid edema; Fig. 1B, axial computed tomography scan) that resulted in complete visual loss even after urgent cantholysis and drainage of a circumferential orbital abscess (Fig. 1C). On the first postoperative day, DWI (Fig. 2A) and ADC (Fig. 2B; optic nerves ADC values: right 1.034 s/mm2, left: 0.63 s/mm2) showed restricted diffusion along the entire extension of the left optic nerve (ON) indicating ischemia. The authors believe that the optic nerve ischemia resulted from the compression of the optic nerve pial vessels by the acute orbital compartment syndrome. Orbital hypertension also compressed the short posterior ciliary arteries and central retinal artery causing retinal and choroidal ischemia (Fig. 2C,D; optical coherence tomography: edema and complete disorganization of retinal layers). This case highlights that optic nerve ischemia is a mechanism of visual loss in orbital compartment syndromes.

Should planning of cervical pedicle screws be race specific? Computed tomography–based morphometric analysis

Introduction: The neurovascular surgical structures are protected by quantitative understanding of cervical pedicle morphology and aiding in better surgical outcome. Aim of the study is to do morphometric analysis of subaxial cervical pedicle by noncomputerized computed tomography (CT) scans. Materials and Methods: From 50 volunteers, a total of 500 cervical pedicles were evaluated using axial and sagittal CT scan. Five parameters such as outer pedicle width (OPW), inner pedicle width (IPW), pedicle height (PH), pedicle transverse angle (PTA) and pedicle axis length (PAL) were analyzed. Result: OPW, IPW, PH, and PAL show increase in values from C3 to C7, while PTA shows a decrease in value from C3 to C7. Conclusion: The cervical pedicle dimension of our study population was smaller than other studies carried out on Asian and European population. Hence, the planning for pedicle screw fixation should be race specific.