Cervical Computed Tomography Imaging Research Articles

Radiologic Examination of High Riding Vertebral Artery and Analysis of Secure Areas

ObjectiveTo radiologically examine the pedicle, lamina, and vertebral artery foraminal anatomies at the C2 vertebra for pedicular and laminar screw instrumentation at the axis in a Turkish population. Materials and MethodsFrom 2018 to 2019, we evaluated 100 patients who underwent cervical computed tomography (CT) for various reasons (excluding cervical pathologies) at Marmara University Hospital. The C2 pedicles were measured on CT images using measurement tools. In addition, axial computed tomography was performed at 0.1-mm intervals. Bilateral measurements were performed for each case. ResultsThe median right and left pedicle axial diameters were respectively 5.01 and 5.09 mm for the male patients and 4.31 and 4.38 mm for the female patients, showing a statistically significant difference between the sexes (p < 0.01). Of the patients, 15% had narrow pedicles. The pedicle sagittal diameters were smaller than 5 mm in 30% of the computed tomographic series. The internal height was <2 mm in 4% of the cases. ConclusionOur findings suggest significant individual and sex-related differences. Vertebral artery groove anomalies are commonly observed. Before performing a posterior craniocervical instrumentation surgery, a CT examination is beneficial because high-riding vertebral arteries must be kept in mind in determining the appropriate screw diameter and screw trajectory.

Interrater Reliability of Cervical Neural Foraminal Stenosis Using Traditional and Splayed Reconstructions: Analysis of One Hundred Scans

The oblique sagittal orientation of the cervical neural foramina hinders the evaluation of cervical neural foraminal stenosis (CNFS) on traditional axial and sagittal slices. Traditional image reconstruction techniques to generate oblique slices provide only a view of the foramina unilaterally. We present a simple technique for generating splayed slices that show the bilateral neuroforamina simultaneously and assess its reliability compared with traditional axial windows. Cervical computed tomography (CT) scans from 100 patients were retrospectively collected and de-identified. The axial slices were reformatted into a curved reformat with the plane of the reformat extending across the bilateral neuroforamina. The foramina along the C2-T1 vertebral levels were assessed by 4 neuroradiologists using the axial and splayed slices. The intrarater agreement across the axial and splayed slices for a given foramen and the interrater agreement for the axial and splayed slices individually were calculated using the Cohen κ statistic. Interrater agreement was overall higher for the splayed slices (κ= 0.25) compared with the axial slices (κ= 0.20). The splayed slices were more likely to have fair agreement across raters compared with the axial slices. Intrarater agreement between the axial and splayed slices was poorer for residents compared with fellows. Splayed reconstructions showing the bilateral neuroforamina en face can be readily generated from axial CT imaging. These splayed reconstructions can improve the consistency of CNFS evaluation compared with traditional CT slices and should be considered in the workup of CNFS, particularly for less experienced readers.

Freehand Regional Techniques for Subaxial Cervical Pedicle Screw Placement.

Although various subaxial cervical pedicle screw implantation techniques have been proposed, clinical operators have been unable to exactly determine the entry points and trajectory . The objective of this article is to propose freehand regional techniques (FRT) for subaxial cervical pedicle screw placements and to investigate the clinical effectiveness of FRT. A total of 80 consecutive patients who underwent open subaxial cervical pedicle screw fixation using FRT from January 2015 to December 2020 were retrospectively reviewed, and preoperative cervical computed tomography (CT) images were used to observe the entry point and screw trajectory. The horizontal and vertical lines at the center of the cervical lateral mass was marked, and the entry point was chosen at the outer upper quadrant of the lateral mass. Both sagittal and axial trajectories were determined by CT images, generally perpendicular to the cervical laminae. Screw implantation accuracy was assessed using postoperative CT. After virtually inserting pedicle screws by FRT on preoperative cervical CT images, all of the entry points were located in the outer upper quadrant of the lateral mass and the trajectory perpendicular to the cervical laminae was just parallel to the pedicle's axis. A total of 694 pedicle screws were placed by FRT clinically, with a 96% accuracy rate. Pedicle screw implantation by FRT for subaxial cervical spine can be performed with acceptable safety and accuracy.

Comparison between the coronal diameters of the cervical spinal canal and spinal cord measured using computed tomography and magnetic resonance imaging in Korean patients.

BackgroundIf the proportion of the spinal cord in the epidural space can be determined under C-arm fluoroscopy during cervical epidural block, a safe entry point for the epidural needle can be established. The aim of this study was the measurement of the cord to canal transverse diameter ratio of each cervical spines. MethodsWe retrospectively evaluated the imaging data of 100 patients who underwent both cervical computed tomography (CT) and cervical magnetic resonance imaging (MRI) at our hospital. We measured the diameters of the spinal canal and spinal cord from the 3rd cervical vertebra to the 1st thoracic vertebra (T1) at each level by using the patients’ cervical CT and MRI images. The spinal cord and spinal canal diameters were measured in the transverse plane of the cervical MRI and CT images, respectively.ResultsThe spinal cord to spinal canal diameter ratio was the highest at the 4th and 5th cervical vertebrae (0.64 ± 0.07) and the lowest at T1 (0.55 ± 0.06, 99% CI [0.535, 0.565].ConclusionsOur findings suggest that the cord to canal transverse diameter ratio could be used as a reference to reduce direct spinal cord injuries during cervical epidural block under C-arm fluoroscopy. In the C-arm fluoroscopic image, if an imaginary line connecting the left and right innermost lines of the pedicles of T1 is drawn and if the needle is inserted into the outer one-fifth of the left and right sides, the risk of puncturing the spinal cord would be relatively reduced.

A new posterior stabilization technique in pediatric subaxial cervical vertebrae: Stabilization of spinous processes with the microplate/screw system: A radiological anatomy study.

There are limited options for posterior stabilization techniques in cases of cervical subaxial instability in children. We designed this study to investigate whether the spinous process (SP) stabilization, which was previously used in adults, can also be used in children. Children aged 4-12 years who were admitted to our hospital between 2012 and 2020 and underwent 3D cervical computed tomography (CT) were retrospectively screened. Children without cervical spine fractures, tumors, deformities, or any ab-normalities and motion artifacts on CT were included in the study. Eight hundred seventy children were identified. Then, 360 children randomly selected from the patient pool were divided into nine different age groups or 3 different age groups (4-6 years, 7-9 years, and 10-12 years). The length, height, thickness, and anomalies of subaxial SPs were studied on CT images of children. The suitability of the SPs for the microplate/screw stabilization system was investigated. The suitability rate for screw insertion was 57.6% and the suitability rate for the stabilization in at least one segmental unit was 74.7%. The eligibility rate for stabilization involving C3, 4, 5, 6, and 7 vertebrae was 16.1%. There were nine different stabilization combinations and C6-7 segmental unit (71.9%) were the most common in those combinations. Bifidity prevented screw insertion in 21% of children. We found that the screw acceptance rate of SP started to increase statistically around 8 years of age and the number of segmental units that could be stabilized was at the age of 10-12 at most. According to the results of this study, we believe that the SP stabilization method recommended for children can be used as a salvage method, to support anterior stabilization or alone in a small number of selected cases.

One-year follow-up for type II odontoid process fractures in octogenarians: Is there a place for surgical management?

Background: Type II odontoid fractures are becoming one of the most common injuries among elderly patients and are associated with increased morbidity rates. Here, we compared the safety/efficacy of conservative versus surgical treatment for type II C2 fractures and, in particular, evaluated the complications, hospital lengths of stay, and mortality rates for patients over 80 years of age.Methods: We retrospectively reviewed the records of 63 nonsurgically versus 18 surgically treated C2 fractures in patients over 80 years of age (2003–2018). Cervical computed tomography images, X-rays, and magnetic resonance images were reviewed by both a neurosurgeon and a neuroradiologist. The following patient data were included in the analysis; Glasgow Coma Scale score, injury severity score, the abbreviated injury scale scores, their comorbidities (e.g., utilizing the Charlson comorbidity index), their primary outcomes, and mortality rates (e.g., at 6 weeks and 1 year after treatment).Results: Eighty-one patients were included in the study; 63 were treated conservatively and 18 underwent surgical management of type II C2 fractures. Patients averaged 87.0 ± 5.0 years of age, and their combined mortality rates were 13.6% at 6 weeks and 25.9% at 1 year. Notably, at 1 year, the mortality rates were not statistically different between the two groups: 18 (30.0%) patients from the conservatively treated group versus 3 (16.7%) patients from the surgically managed patients died indicating (e.g., using the Kaplan–Meier analysis) no survival advantage for either treatment strategy.Conclusion: Surgical versus conservative management of type II odontoid fractures were associated with comparable high mortality rates at 1 year.

Bicortical Laminar Screws for Posterior Fixation of Subaxial Cervical Spine: A Radiologic Analysis With Computed Tomography Images.

Study Design:Retrospective radiological analysis.Objectives:Translaminar screw (TLS) placement is one of the fixation techniques in the subaxial cervical spine. However, it can be difficult to use in small diameter of the lamina. This study proposed a novel bicortical laminar screw (BLS) and analyzed the related parameters using computed tomography (CT).Methods:Cervical CT images taken at our institution from January 2013 to March 2017 were used for measurement. On the axial images, the maximum screw length (MSL) and trajectory angle (TA) of BLS and TLS were measured, together with the distance from the midline (DM) to the BLS entry point and the lamina width (LW). On the parasagittal images, the height of the lamina (LH) was measured.Results:MSL of BLS and TLS were 21.00 and 20.97 mm, 19.02 and 20.91 mm, 18.45 and 21.01 mm, and 20.00 and 21.01 mm in C3, C4, C5, and C6, respectively. TA of the BLS and TLS were 21.24° and 34.90°, 19.05° and 34.22°, 18.65° and 33.61°, and 18.30° and 34.51° at C3, C4, C5, and C6, respectively. DM were 6.44, 5.77, 5.68, and 6.03 at C3, C4, C5, and C6, respectively. LW and LH were 3.52 and 12.44 mm, 2.87 and 12.49 mm, 2.76 and 12.42 mm, and 3.18 and 13.30 mm at C3, C4, C5, and C6, respectively.Conclusion:We suggest that BLS fixation is a feasible alternative option for posterior fixation to the lamina of the subaxial cervical spine. It may be especially useful when pedicle screw, lateral mass screw, and TLS are not appropriate.

Patients' and Physicians' Knowledge of Radiation Exposure Related to Spine Surgery.

Cross-sectional survey. Examine patients' and physicians' estimates of radiation exposure related to spine surgery. Patients are commonly exposed to radiation when undergoing spine surgery. Previous studies suggest that patients and physicians have limited knowledge about radiation exposure in the outpatient setting. This has not been assessed for intraoperative imaging. A questionnaire was developed to assess awareness/knowledge of radiation exposure in outpatient and intraoperative spine care settings. Patients and surgeons estimated chest radiograph (CXR) equivalent radiation from: cervical and lumbar radiographs (anterior-posterior [AP] and lateral), computed tomography (CT), magnetic resonance imaging (MRI), intraoperative fluoroscopy, and intraoperative CT (O-arm). Results were compared to literature-reported radiation doses. Overall, 100 patients and 26 providers completed the survey. Only 31% of patients were informed about outpatient radiation exposure, and only 23% of those who had undergone spine surgery had been informed about intraoperative radiation exposure. For lumbar radiographs, patients and surgeons underestimated CXR-equivalent radiation exposures: AP by five-fold (P < 0.0001) and seven-fold (P < 0.0001), respectively, and lateral by three-fold (P < 0.0001) and four-fold (P = 0.0002), respectively. For cervical CT imaging, patients and surgeons underestimated radiation exposure by 18-fold (P < 0.0001) and two-fold (P = 0.0339), respectively. For lumbar CT imaging, patients and surgeons underestimated radiation exposure by 31-fold (P < 0.0001) and three-fold (P = 0.0001), respectively. For intraoperative specific cervical and lumbar imaging, patients underestimated radiation exposure for O-arm by 11-fold (P < 0.0001) and 22-fold (P = 0.0002), respectively. Surgeons underestimated radiation exposure of lumbar O-arm by three-fold (P = 0.0227). This study evaluated patient and physician knowledge of radiation exposure related to spine procedures. Underestimation of radiation exposure in the outpatient setting was consistent with prior study findings. The significant underestimation of intraoperative cross-sectional imaging (O-arm) is notable and needs attention in the era of increased use of such technology for imaging, navigation, and robotic spine surgery. 4.

Computed tomography-based morphometric measurements of the atlas (C1) posterior arc

Study design: Single-center retrospective study&#x0D; Objectives: This study is performed to determine the anatomic feasibility of the C1 posterior arc screw and help select an optimal screw trajectory in treating patients with craniovertebral junction pathologies.&#x0D; Material and Methods: We reported a single-centre retrospective study. Forty patients (20 male and 20 female) who underwent cervical computed tomography (CT) were chosen from the hospital records. Based on CT images, we measured left laminar length (LLL), right laminar length (RLL), left laminar angle (LLA), right laminar angle (RLA), left laminar axial thickness (LLAT), right laminar axial thickness (RLAT), left laminar coronal thickness (LLCT), right laminar coronal thickness (RLCT), and craniocaudal angle (CCA) of the C1 posterior arc.&#x0D; Results: The mean values and standard deviations (SD) for nine parameters at the C1 posterior arc were determined. LLL, RLL, LLCT, and RLCT were statistically longer in men than women. RLAT was bigger in men but there was no statistical difference. RLA was statistically wider in women than men. LLA and CCA were wider in women but there was no statistical difference, LLAT was bigger in women but there was no statistical difference. There was no statistical difference in measurements by age.&#x0D; Conclusion: The results of this study are important to avoid neurovascular injury and pedicle breakage because of choosing large screw while performing C1 laminar screw fixation.

Direct trans-pedicular screw fixation for atypical hangman’s fracture: A minimally invasive technique using the tubular retractor system

The ideal treatment strategy of atypical hangman’s fracture (AHF) is debatable. If surgical treatment is needed, direct trans-pedicular fixation technique is advantageous in that it stabilizes the fracture site and spares adjacent motion segments. The authors describe relatively simple and minimally invasive technique using the tubular retractor system (TRS) for surgical treatment of AHF. Trans-pedicular screw fixation using the TRS was performed in seven patients with AHF. This technique was facilitated by using intraoperative fluoroscopy and a surgical microscope. Rigid cervical collar was used for 4 weeks, postoperatively. To evaluate postoperative radiological outcomes, cervical computed tomography (CT) was performed at postoperative 6 months. The clinical outcomes, including visual analog scale and neck motion, were evaluated. In surgical outcomes, no intraoperative neuro-vascular injury or postoperative complications occurred. For all patients, dynamic radiographs and CT images demonstrated a stable construct. Clinical examination also showed satisfactory pain relief and restoration of the full range of motion in the neck. Direct trans-pedicular screw fixation using the TRS for AHF appears to be safe and effective. This technique permits less skin incision and muscle dissection with good postoperative recovery. This report serves as a preliminary study and may be a surgical option for minimally invasive direct repair.

Metal artifact reduction on cervical CT images by deep residual learning

BackgroundCervical cancer is the fifth most common cancer among women, which is the third leading cause of cancer death in women worldwide. Brachytherapy is the most effective treatment for cervical cancer. For brachytherapy, computed tomography (CT) imaging is necessary since it conveys tissue density information which can be used for dose planning. However, the metal artifacts caused by brachytherapy applicators remain a challenge for the automatic processing of image data for image-guided procedures or accurate dose calculations. Therefore, developing an effective metal artifact reduction (MAR) algorithm in cervical CT images is of high demand.MethodsA novel residual learning method based on convolutional neural network (RL-ARCNN) is proposed to reduce metal artifacts in cervical CT images. For MAR, a dataset is generated by simulating various metal artifacts in the first step, which will be applied to train the CNN. This dataset includes artifact-insert, artifact-free, and artifact-residual images. Numerous image patches are extracted from the dataset for training on deep residual learning artifact reduction based on CNN (RL-ARCNN). Afterwards, the trained model can be used for MAR on cervical CT images.ResultsThe proposed method provides a good MAR result with a PSNR of 38.09 on the test set of simulated artifact images. The PSNR of residual learning (38.09) is higher than that of ordinary learning (37.79) which shows that CNN-based residual images achieve favorable artifact reduction. Moreover, for a 512 × 512 image, the average removal artifact time is less than 1 s.ConclusionsThe RL-ARCNN indicates that residual learning of CNN remarkably reduces metal artifacts and improves critical structure visualization and confidence of radiation oncologists in target delineation. Metal artifacts are eliminated efficiently free of sinogram data and complicated post-processing procedure.

Evaluating Ossifications of the Nuchal Ligament with Cervical Computed Tomography.

The nuchal ligament (NL) extends from the external occipital protuberance and median nuchal line to the spinous process of the 7th cervical vertebrae. In this study, we evaluated the incidence, location level, and size of ossifications of the NL (ONL) in patients who underwent cervical computed tomography (CT) for various reasons. The present study included 481 patients (187 females and 294 males) who underwent cervical CT from February 2011 to November 2016 due to reasons such as trauma, cervical spondylosis, neck pain, and screening for metastasis. CT was performed using 2- or 8-slice scanners. Archive images of patients on picture archiving and communication system were retrospectively evaluated by two radiologists. The structures in bone density and form detected in NL were evaluated as nuchal ossification. ONL location levels, numbers, and dimensions were determined. The relationship between both sexes and age and the incidence of ONL was investigated. ONL was detected in 44 patients (9.14%). The mean ages of patients with ONL and without ONL were 62.27±13.92 (23-86) and 41.78±20.76 (4-101) years, respectively. There was a statistically significant relationship between ONL and age (p<0.001). Thirty-six patients had one ONL, seven patients had two, and one patient had three. The most common ONL location was the C5 spinous process level (n=12) followed by the C6 spinous process level (n=8). The longest ONL in craniocaudal direction was 20.9 mm, and the shortest one was 3.1 mm. ONL is a smooth-contoured ovoid or round bone structure extending parallel to the longitudinal axis that can frequently be observed as one or multiple occurrences with different sizes on cervical CT images.

Characteristics of Cervical Computed Tomography Findings in Kawasaki Disease

The objective of this study was to characterize cervical computed tomography (CT) findings in Kawasaki disease (KD) patients that may facilitate early diagnosis. We retrospectively reviewed cervical CT images of 78 children with cervical lymphadenopathy to analyze the distribution and morphology of lymphadenopathy and other soft-tissue findings. Twenty-eight patients were diagnosed with KD. Fifty had other diseases (non-KD). Retropharyngeal edema was observed in 82% (23/28) of KD and 30% (15/50) of non-KD (P < 0.01) cases. Retropharyngeal lymphadenopathy was observed in 89% (25/28) of KD and 48% (24/50) of non-KD (P < 0.01) cases. Levels III and IV lymphadenopathy was found in only 1 KD case, whereas levels III and IV lymphadenopathy was found in 58% (29/50) (P < 0.01) and 36% (18/50) (P < 0.01) of non-KD cases, respectively. Retropharyngeal lymphadenopathy and retropharyngeal edema are relatively common features of KD on CT. Given the potentially serious complications of KD, this diagnosis is an important consideration in a young child presenting with these imaging findings.