Prevertebral Soft Tissue Thickness Research Articles

Measurements in cervical vertebrae CT of pediatric cases: normal values

This study aims to determine the normal limits of atlanto-dental interval (ADI), basion-dens interval (BDI), basion-cartilaginous dens interval (BCDI), and prevertebral soft tissue thickness (PVSTT) according to age groups for normal pediatric cases. CT images of 256 pediatric patients aged between 1 and 15years were retrospectively evaluated. ADI, BDI, BCDI and PVSTT measurements were performed. Upper normal limit (UNL) values for ADI were 2.65-4.8mm. UNL values for PVSTT were found to be 6.9mm at C1 level, 6.7mm at C2 level, 9.3mm at C3 level, 14.2mm at C4 level, 14.1mm at C5 level, 13.8mm at C6 level and 12.8mm at C7 level. The maximum value of BDI in the group with non-ossified os terminale was 12mm, and in the group with ossified os terminale it was 10mm. The UNL of BCDI determined for females was 5.1mm, while the UNL for males was 5.6mm. We propose the obtained values as the UNL values for ADI, BDI, BCDI and PVSTT on CT images in the pediatric population from 1 to 15years.

Learning Radiologist’s Step-by-Step Skill for Cervical Spinal Injury Examination: Line Drawing, Prevertebral Soft Tissue Thickness Measurement, and Swelling Detection

Radiologists examine lateral view radiographs of the cervical spine to determine the presence of cervical spinal injury. In this paper, we demonstrate that an artificial intelligence neural network can learn the steps employed by a radiologist when examining these radiographs for possible injury. We deconstructed the decision-making strategy into three steps: line drawing, prevertebral soft tissue thickness (PSTT) measurement, and swelling detection. After training neural networks to be guided by the radiologist’s intermediate labels, the networks successfully performed comparable line drawings to those of the radiologists, and subsequent PSTT measurement and swelling detection were successful. Quantitative comparison of PSTT measurements between our proposed method and radiologists showed a high correlation (r = 0.8663, p < 0.05, and intraclass correlation coefficient = 0.9283 at the C2 level; r = 0.7720, p < 0.05, and intraclass correlation coefficient = 0.8667 at the C6 level). Using the radiologist’s diagnosis as the reference point, the sensitivity, specificity, and accuracy of swelling detection by our proposed method were 100%, 98.37%, and 98.48, respectively. We conclude that our neural networks successfully learned the sequence of skills used by radiologists when interpreting radiographs for injury of the cervical spine.

P.5.c.006 - Behavioral impairments after intranasal administration of alpha-synuclein oligomers in aged mice

Atlantodental interval (ADI), basion-dental interval (BDI) and the thickness of prevertebral soft tissue (TOPST) measured in lateral cervical radiographs were reported to be useful indicators and indirect signs of underlying cervical spine injuries. However, cervical computed tomography (MDCT) is the first method of imaging used in all trauma patients and upper normal limits (UNLs) of cervical distances according to age and sex are undetermined. Therefore, we aimed to calculate these metrics.500 adult trauma patients with cervical MDCT at the time of admission were retrospectively selected. ADI, BDI, and TOPSTs were measured by two blinded researchers.488 cervical spine CT scans were reported to be normal and 12 has pathological findings. Mean ADI, BDI and TOPST of C1, C2, C6 and C7 were statistically significantly wider in males. In females, ADI and BDI were significantly narrower with the increase in age. In males, only ADI was significantly narrower, and TOPST of C6 and C7 vertebra were significantly wider with the increase in age. We found the optimal UNLs as follows: ADI 2.5 mm, BDI 8.5 mm, C1 6.5 mm, C2 5.7 mm, C3 6.3 mm (6 mm for C1–3 for practical purposes), C4 11.7 and C5–7 17 mm.We believe that the increase in distances with age may be affected by the height losses of discs and vertebral bodies, formation of anterior osteophytes and regional kyphosis by age. Those results were compatible with the previous reports.

Effect of Local Steroid Injection on Prevertebral Soft Tissue Swelling Following Anterior Cervical Discectomy and Fusion

Background: Prevertebral soft tissue swelling (PSTS) following anterior cervical surgery, may proceed to airway compromise which is potentially lethal. We plan to evaluate the effect of local steroid injection to reduce PSTS after anterior cervical discectomy and fusion (ACDF).Methods: In a randomized clinical trial 66 patients who underwent ACDF involving one to three segments due to radiculopathy or myelopathy were enrolled and randomly divided to two groups of 38 with local injection of 80 mg methylprednisolone in operation site, and control. Prevertebral soft tissue thickness to mid anteroposterior vertebral body diameter (S/V) ratio was defined to assess PSTS. In addition, dysphagia and pain at surgery site was evaluated using Bazaz dysphagia scale and Visual Analogue Scale (VAS) respectively, at 1st, 5th and 10th post-operative days.Results: We have observed significantly lower S/V ratio in all studied vertebrae, except C6 on second postoperative day in case group. At the end of the 6th month, there was no significant difference for S/V ratio in any level in two groups. Severity of dysphagia was significantly lower in 1st, 5th and 10th post-operative day in patients in case group. (P value<0.05) Also, patients in case group experienced significantly less severe odynophagia at 1st, 5th and 10th post-operative day, which was assessed by VAS. (P value<0.05)Conclusions: The use of local methyl prednisolone in prevertebral space is a simple and effective method to reduce PSTS and severity of dysphagia and odynophagia. Furthermore, this method was not associated with any adverse effects.

Effect of Swallowing Function After ROI-C Anterior Cervical Interbody Fusion

The difference of swallowing function between a new zero-notch anterior cervical interbody fusion device (ROI-C) and classical method with the plate using in anterior cervical decompression and fusion (ACDF) were discussed and analyzed. 57 cases in the First Affiliated Hospital of Jinan University from Feb 2013 to Mar 2016 who underwent ACDF were retrospectively reviewed. There were 33 cases in group using with ROI-C and 24 cases in group using with plate. The difference of dysphagia incidence and severity were analyzed by comparing with the image data before and after operation. The dysphagia correlative risk factors analyzed by logistic regression test were internal fixation material and thickness of 3-days post-operative prevertebral soft tissue (PST). When the PST (3-days post-operative) was larger than 10.44mm, the chance of developing postoperative was significantly greater. The thickness of 3-days post-operative PST in ROI-C group was significantly lower than that in plate group (P 0.05). 3-days post-operation, the dysphagia incidence and severity were significantly lower in ROI-C group than that in plate group (P <0.05). The dysphagia correlative risk factors are internal fixation material and thickness of 3-days post-operative PST. When the 3-days post-operative PST larger than 10.44 mm, the chance of developing postoperative is significantly greater. Zero-notch ROI-C anterior cervical interbody fusion device is associated with less stimulations to esophagus, lower postoperative dysphagia incidence, milder severity of dysphagia and shorter period of dysphagia in ACDF.

Normal values of cervical vertebral measurements according to age and sex in CT

IntroductionAtlantodental interval (ADI), basion-dental interval (BDI) and the thickness of prevertebral soft tissue (TOPST) measured in lateral cervical radiographs were reported to be useful indicators and indirect signs of underlying cervical spine injuries. However, cervical computed tomography (MDCT) is the first method of imaging used in all trauma patients and upper normal limits (UNLs) of cervical distances according to age and sex are undetermined. Therefore, we aimed to calculate these metrics. Methods500 adult trauma patients with cervical MDCT at the time of admission were retrospectively selected. ADI, BDI, and TOPSTs were measured by two blinded researchers. Results488 cervical spine CT scans were reported to be normal and 12 has pathological findings. Mean ADI, BDI and TOPST of C1, C2, C6 and C7 were statistically significantly wider in males. In females, ADI and BDI were significantly narrower with the increase in age. In males, only ADI was significantly narrower, and TOPST of C6 and C7 vertebra were significantly wider with the increase in age. We found the optimal UNLs as follows: ADI 2.5mm, BDI 8.5mm, C1 6.5mm, C2 5.7mm, C3 6.3mm (6mm for C1–3 for practical purposes), C4 11.7 and C5–7 17mm. DiscussionWe believe that the increase in distances with age may be affected by the height losses of discs and vertebral bodies, formation of anterior osteophytes and regional kyphosis by age. Those results were compatible with the previous reports.

Swallowing Function Defined by Videofluoroscopic Swallowing Studies after Anterior Cervical Discectomy and Fusion: a Prospective Study.

This study evaluated factors related to swallowing dysfunction after anterior cervical discectomy and fusion (ACDF) using videofluoroscopic swallowing studies (VFSS). Preoperative and postoperative VFSSs were done with 5 mL diluted barium. Oral transit time, pharyngeal delay time, pharyngeal response time (PRT), and pharyngeal transit time were measured. Hyoid bone movement and upper esophageal sphincter (UES) diameter were measured serially. Thickness of prevertebral soft tissue was measured from digitized VFSS images. In results, 12 of 20 patients showed abnormal postoperative VFSS findings. PRT decreased significantly after surgery. Hyoid bone movement did not change significantly after surgery. The maximal distance of UES opening decreased significantly after surgery, and the higher the level of surgery (C3 > C4 > C5 > C6), the greater the decrease in maximal distance of the UES opening after surgery. The time to widest opening of the UES was prolonged significantly. At the C3 and C4 levels, the change in prevertebral soft tissue thickness of patients with VFSS abnormalities was significantly greater than those without abnormalities. In conclusion, patients after ADCF with their highest surgery level at C3 and C4 showed more abnormal VFSS findings, significantly increased soft tissue thickness, and decreased maximal distance of UES opening. VFSS provided objective data related with swallowing dysfunction after ACDF.

A CLOSER LOOK TO PREVERTEBRAL SOFT TISSUE THICKNESS ON MAGNETIC RESONANCE IMAGES

Our purpose is to determine the upper limits of normal prevertebral soft tissue thickness and analyze the effect of age, sex and body mass index (BMI) on MRI. To the best of our knowledge, the relationship among PVST thickness and body mass index has not been evaluated earlier. Material and Methods: PVST thickness was measured in 210 patients undergoing cervical MRI for disc pathology. Subjects with congenital anomaly, trauma and malignancy were excluded from the study. Results: A total of 123 subjects (F/M: 91/32; mean age: 42.98±13.45; age range: 20-73) were included to the study. There was a statistically significant relationship between BMI and PVST thickness. The upper limits of normal for the thickness of the PVST were 10.3 mm at C1, 6.8 mm at C2, 7.1mm at C3, 15.9 mm at C4, 19 mm at C5, 18.8 at C6 and 21.1 at C7 levels. There was a statistically significant relationship between sex, age and PVST thickness at C6 and C7 levels. Conclusions: The normal levels of PVST thickness in the cervical region obtained on MRI could be used as part of a screening test in future. BMI influence PVST thickness probably by changing the thickness of fat plane in the cervical region. Sex and age appear to be the determinants of the thickness at C6 and C7 levels.

Estimation of normal computed tomography measurements for the upper cervical spine in the pediatric age group.

Upper cervical spine injuries in the pediatric age group have been recognized as extremely unstable from ligamentous disruption and as potentially lethal. Few measurement norms have been published for the pediatric upper cervical spine to help diagnose this pathological state. Instead, adult measurement techniques and results are usually applied inappropriately to children. The authors propose using high-resolution reconstructed CT scans to define a range of normal for a collection of selected upper cervical spine measurements in the pediatric age group. Sagittal and coronal reformatted images were obtained from thin axial CT scans obtained in 42 children (< 18 years) in a 2-month period. There were 25 boys and 17 girls. The mean age was 100.9 months (range 1-214 months). Six CT scans were obtained for nontrauma indications, and 36 were obtained as part of a trauma protocol and later cleared for cervical spine injury. Six straightforward and direct linear distances-basion-dental interval (BDI); atlantodental interval (ADI); posterior atlantodental interval (PADI); right and left lateral mass interval (LMI); right and left craniocervical interval (CCI); and prevertebral soft-tissue thickness at C-2-that minimized logistical and technical distortions were measured and recorded. Statistical analysis including interobserver agreement, age stratification, and sex differences was performed for each of the 6 measurements. The mean ADI was 2.25 ± 0.24 mm (± SD), the mean PADI was 18.3 ± 0.07 mm, the mean BDI was 7.28 ± 0.10 mm, and the mean prevertebral soft tissue width at C-2 was 4.45 ± 0.43 mm. The overall mean CCI was 2.38 ± 0.44 mm, and the overall mean LMI was 2.91 ± 0.49 mm. Linear regression analysis demonstrated statistically significant age effects for PADI (increased 0.02 mm/month), BDI (decreased 0.02 mm/month), and CCI (decreased 0.01 mm/month). Similarly significant effects were found for sex; females demonstrated on average a smaller CCI by 0.26 mm and a smaller PADI by 2.12 mm. Moderate to high interrater reliability was demonstrated across all parameters. Age-dependent and age-independent normal CT measurements of the upper cervical spine will help to differentiate physiological and pathological states in children. The BDI appears to change significantly with age but not sex; on the other hand, the LMI and ADI appear to be age-independent measures. This preliminary study suggests acceptable levels of interrater reliability, and further expanded study will aim to validate these measurements to produce a profile of normal upper cervical spine measurements in children.

Three-dimensional airway analysis of trumpet players vs. non-trumpet players

The aim of this retrospective, radiographic study was to determine if there is a significant difference between the most constricted area of the airway (MCA), airway dimensions (length and volume) of the nasal cavity, nasopharynx, oropharynx, maxillary sinuses, and prevertebral soft tissue thickness of trumpeter players vs. controls utilizing three-dimensional cone beam computed tomography (3D-CBCT). The second aim was to determine significant differences in the prevalence of airway pathologies between trumpet players and controls. Following reliability studies, 3D-CBCTs of 66 Caucasian trumpeters were analyzed with 22 ethnic-matched controls. Measurements of airway parameters and pathology were compared between the two groups. An analysis of covariance, with age and sex included as covariates, was used to compare the airway measures. Since there was a significant difference in gender and age, comparisons between groups for the presence of airway pathology was made using logistic regression including age and sex as covariates. A 5 % significance level was used for all comparisons. The trumpet players had significantly smaller nasal cavity volume (p < 0.0001) and significantly greater soft tissue thickness at CV2ia (p = 0.03) and CV3sa (p = 0.005). No other airway measure demonstrated a significant difference between the two groups. There was a significant difference (p = 0.002) in airway pathology between trumpeters (n = 33; 50 %) and the controls (n = 4; 18 %). Trumpeter’s airways showed a decreased nasal volume and greater oropharyngeal soft tissue thickness compared with controls. Trumpeters were almost three times as likely to exhibit some type of airway pathology when compared to controls.

Anterior cervical discectomy and fusion with a zero-profile integrated plate and spacer device: a clinical and radiological study: Clinical article.

Anterior cervical plating decreases the risk of pseudarthrosis following anterior cervical discectomy and fusion (ACDF). Dysphagia is a common complication of ACDF, with the anterior plate implicated as a potential contributor. A zero-profile, stand-alone polyetheretherketone (PEEK) interbody spacer has been postulated to minimize soft-tissue irritation and postoperative dysphagia, but studies are limited. The object of the present study was to determine the clinical and radiological outcomes for patients who underwent ACDF using a zero-profile integrated plate and spacer device, with a focus on the course of postoperative prevertebral soft-tissue thickness and the incidence of dysphagia. Using a surgical database, the authors conducted a retrospective analysis of all patients who had undergone ACDF between August 2008 and October 2011. All patients received a Zero-P implant (DePuy Synthes Spine). The Neck Disability Index (NDI) and visual analog scale (VAS) scores for arm and neck pain were documented. Dysphagia was determined using the Bazaz criteria. Prevertebral soft-tissue thickness, spinal alignment, and subsidence were assessed as well. Twenty-two male and 19 female consecutive patients, with a mean age of 58.4 ± 14.68, underwent ACDF (66 total operated levels) in the defined study period. The mean clinical follow-up in 36 patients was 18.6 ± 9.93 months. Radiological outcome in 37 patients was assessed at a mean follow-up of 9.76 months (range 7.2-19.7 months). There were significant improvements in neck and arm VAS scores and the NDI following surgery. The neck VAS score improved from a median of 6 (range 0-10) to 0 (range 0-8; p < 0.001). The arm VAS score improved from a median of 2 (range 0-10) to 0 (range 0-7; p = 0.006). Immediate postoperative dysphagia was experienced by 58.4% of all patients. Complete resolution was demonstrated in 87.8% of affected patients at the latest follow-up. The overall median Bazaz score decreased from 1 (range 0-3) immediately postoperatively to 0 (range 0-2; p < 0.001) at the latest follow-up. Prevertebral soft-tissue thickness significantly decreased across all levels from a mean of 15.8 ± 4.38 mm to 10.1 ± 2.93 mm. Postoperative lordosis was maintained at the latest follow-up. Mean subsidence from the immediate postoperative to the latest follow-up was 4.1 ± 4.7 mm (p < 0.001). Radiographic fusion was achieved in 92.6% of implants. No correlation was found between prevertebral soft-tissue thickness and Bazaz dysphagia score. A zero-profile integrated plate and spacer device for ACDF surgery produces clinical and radiological outcomes that are comparable to those for nonintegrated plate and spacer constructs. Chronic dysphagia rates are comparable to or better than those for previously published case series.

Comparative study of clinical and radiological outcomes of a zero-profile device concerning reduced postoperative Dysphagia after single level anterior cervical discectomy and fusion.

ObjectiveThis study analyzed clinical and radiological outcomes of a zero-profile anchored spacer (Zero-P) and conventional cage-plate (CCP) for single level anterior cervical discectomy and fusion (ACDF) to compare the incidence and difference of postoperative dysphagia with both devices.MethodsWe retrospectively reviewed our experiences of single level ACDF with the CCP and Zero-P. From January 2011 to December 2013, 48 patients who had single level herniated intervertebral disc were operated on using ACDF, with CCP in 27 patients and Zero-P in 21 patients. Patients who received more than double-level ACDF or combined circumferential fusion were excluded. Age, operation time, estimated blood loss (EBL), pre-operative modified Japanese Orthopaedic Association (mJOA) scores, post-operative mJOA scores, achieved mJOA scores and recovery rate of mJOA scores were assessed. Prevertebral soft tissue thickness and postoperative dysphagia were analyzed on the day of surgery, and 2 weeks and 6 months postoperatively.ResultsThe Zero-P group showed same or favorable clinical and radiological outcomes compared with the CCP group. Postoperative dysphagia was significantly low in the Zero-P group.ConclusionsApplication of Zero-P may achieve favorable outcomes and reduce postoperative dysphagia in single level ACDF.

Analysis on the causes of dysphagia after multilevel anterior cervical discectomy and fusion

Objective To investigate incidence and related factors of dysphagia after fusion with an anterior cervical plate plus cage or a stand-alone cage (Zero-p cage) following anterior cervical discectomy procedure for treating multilevel cervical spondylotic myelopathy (MCSM).Methods From September 2008to September 2011,226 patients with MCSM underwent anterior cervical discectomy and fusion using an anterior cervical plate plus cage (118 patients,P&C group) or a stand-alone cage (108 patients,Zero-p group).Neurological function was evaluated by Japan orthopedic association (JOA) scores before and after operation.Cervical X-rays were taken to assess the graft fusion,internal fixation related complications and the thickness of the prevertebral soft tissue.The Bazaz dysphagia score and Swallowing Quality of Life questionnaire were used to assess the incidence and degree of dysphagia.Results The average follow-up time was 2.4years (range,1.0 to 3.5 years).The incidence of dysphagia was 41.53％ in P&C group,while 33.33％ in Zero-p group at 2 days after operation.The thickness of the prevertebral soft tissue in P&C group was significantly thicker than that in Zero-p group at 2 days and 2 months after surgery.In Zero-p group,the incidence of dysphagia was 43.1％ in patients who underwent operation from C3 to C6,while 22％ in patients who underwent operation from C4 to C7.Conclusion Dysphagia is common after multilevel anterior cervical discectomy and fusion.The choice of implants and the extent of operation are important influencing factors of postoperative dysphagia.The use of stand-alone cage can decrease the incidence of dysphagia.The operation at higher levels has a higher incidence of dysphagia. Key words: Cervical vertebrae; Spinal cord compression; Spinal fusion; Deglutition disorders

Does the ratio and thickness of prevertebral soft tissue provide benefit in blunt cervical spine injury?

Although many reports advocate computed tomography (CT) as the initial surveillance tool for occult cervical spine injury (CSI) at the emergency department (ED), the role of a lateral cervical spine radiograph (LCSX) has still not been replaced. We hypothesized that the increased width of the prevertebral soft tissue on an LCSX provides helpful information for selecting the high-risk patients who need to be evaluated with more accurate diagnostic tools. This was a retrospective and consecutive series of injured patients requiring cervical spine evaluation who were first imaged with three-view plain films at the ED. The prevertebral soft tissue thickness (PVST) and ratio of prevertebral soft tissue thickness to the cervical vertebrae diameter (PVST ratio) were calculated on the LCSX. Suspicion of CSI was confirmed by either CT or magnetic resonance imaging (MRI) scans. A total of 826 adult trauma patients requiring cervical spine evaluation were enrolled. The C3 PVST and PVST ratio were significantly different between patients with or without upper cervical area injury (UCAI, 8.64 vs. 5.49mm, and 0.394 vs. 0.276, respectively), and, likewise, the C6 PVST and PVST ratio for patients with or without lower cervical area injury (LCAI, 16.89 vs. 14.66mm, and 0.784 vs. 0.749, respectively). The specificity was greater than 90% in predicting UCAI and LCAI when combining these two parameters. This method maximizes the usefulness of LCSX during the initial assessment of a conscious patient with blunt head and neck injury, especially for the identification of high-risk patients requiring prompt CT or MRI; on the other hand, it prevents the overuse of these high-cost imaging studies as initial diagnostic tools.

Evaluation of the prevertebral soft tissue thickness by magnetic resonance imaging in patients with mild neck problem

We encountered no study conducted on the evaluation of prevertebral soft tissue (PVST) thickness by magnetic resonance imaging (MRI) during our literature search. Measuring PVST thickness by MRI in the cervical region of adult cases was aimed in the present retrospective study. For the intended purpose, a total of 136 patients, composed of both males and females, with ages ranging from 20 to 69 years, in whom no pathology in the cervical prevertebral region was revealed by MRI modality implemented for various reasons, were included in the study. The upper limit of normal for PVST thickness was measured in our study to be 10 mm, 7 mm and 20 mm at C1, C2-C3 and C6-C7 vertebral levels, respectively. The least variation in the measurements and standard deviations were obtained at C3-C4 vertebral levels. Upon making a comparison between the measured PVST thicknesses on the basis of gender, the measurements at C2,C4 and C7 were found to display significant difference, whereas that was not the case for the measurements obtained at the other levels. Progressively widespread use of MRI for the traumas inflicting the cervical region makes it obligatory to specify normal values for the thickness of PVST measured by MRI.

Normal Pediatric Prevertebral Soft-Tissue Thickness on MDCT

The thickness of the prevertebral soft tissue (PVST) is instrumental in helping detect cervical spine injuries in the pediatric population. Current parameters for normal PVST thickness in that population are based on lateral radiographs because there have been no studies to date defining age-dependent normal measurements on MDCT. With the increasingly important role of MDCT in the evaluation of pediatric trauma patients, it is necessary to establish normal values for pediatric PVST thickness on MDCT images. Thus, the purpose of this study is to establish the normal thickness of PVST on MDCT of the pediatric population from 0 to 15 years old. The thickness of the PVST was measured in 139 pediatric trauma patients (age range 0-15 years) who presented to the pediatric emergency department between 2005 and 2008. Patients included in the study were not intubated, had no congenital or acquired osseous abnormality detected on CT, and were discharged from the hospital without a diagnosis of cervical spine or soft-tissue injury. Exclusion criteria included patients with concurrent injury found on head CT or nontraumatic causes of PVST thickening, such as lymphadenopathy or retropharyngeal internal carotid arteries. Patients who were diagnosed with cervical injuries within 1 year after the initial CT examination were also excluded. Each patient was scanned with a cervical collar placing the cervical spine in a neutral or near-neutral position. The smallest variability and calculated SD were at C2 and C6. The upper limits of normal for PVST thickness at C2 were 7.6 mm in patients from 0 to 2 years old, 8.4 mm in patients from 3 to 6 years old, and 6.8 mm in patients from 7 to 10 years old and in those from 11 to 15 years old. At the C6 level, the upper limits were 9.0 mm in patients from 0 to 2 years old, 9.8 mm in patients from 3 to 6 years old, 12.1 mm in patients from 7 to 10 years old, and 14.5 mm in patients from 11 to 15 years old. The upper limit of normal had the highest variability at C3 and C4 for all age groups. The thickness of the PVST is important in the detection of underlying injuries to the cervical spine. MDCT is playing an increasingly important role in the evaluation of pediatric trauma patients. We propose the obtained values as the upper limits of normal for PVST thickness on MDCT images in the pediatric population from 0 to 15 years old.

Measurement of Prevertebral Cervical Soft Tissue Thickness on Lateral Digital Radiographs

Widening of the prevertebral soft tissues is one of several significant indirect signs of cervical spine trauma. This paper provides pediatric radiographic reference measurements for prevertebral soft tissues at C2 and C6, and for the ratio of soft tissue to vertebral width at C6. We reviewed 327 radiographs of consecutive patients under 14 years of age presenting at a trauma unit and obtained the relevant measurements using a software tool. Patients included in the study had no clinical features of cervical spine injury. Interobserver reliability of the measurements was assessed using the intraclass correlation coefficient of reliability. The effect of age category on the measurements was tested. Interobserver reliability was high for all measurements. The mean soft tissue width at C6 was significantly different across 3 age categories, whereas there was no significant difference for the soft tissue at C2 or the C6 ratio. The highest C2 soft tissue measurement was 10.6 mm, whereas the mean was 4.3 mm. The highest ratio at C6 was 1.2, with a mean ratio of 0.69. We present prevertebral soft tissue measurements from a larger sample of subjects than published previously, which allows our values to be used with more confidence as a tool in screening for cervical spine injury.

Prevertebral Soft Tissue Thickness among Pediatric Patients

Objective: This study aimed to determine the prevertebral soft tissue thickness among normal patients aged 0-14 years old in a tertiary government training hospital, to compare these values with divergent criteria in the standard otorhinolaryngology and radiology texts used in our institution, and to recommend adoption of a set of criteria based on the results. &#x0D; Methods&#x0D; Study Design: Descriptive Study&#x0D; Setting: Tertiary Government Hospital &#x0D; Subjects and Methods: Lateral cervical radiographs taken from May 2007 to August 2009 which were initially read as normal were collected. Fifty (50) patients, 39 males and 11 females, aged 0-14 years old meeting inclusion criteria were reviewed and prevertebral soft tissue thicknesses (PVST) and cervical vertebral body diameter at levels C2, C5, C6 were measured and compared to criteria set by standard otorhinolaryngology and radiology textbooks. &#x0D; Results: The average PVST at C2 ranged from 4.02 mm for 2–3 year-olds (n= 2) to 8.16 mm for 1 –2 year-olds (n=2). The average PVST at C5 ranged from 8.11mm for 1–2 year-olds to 10.75 mm for for 0-1 year-olds. The average PVST at C6 ranged from 7.13 mm for 1 – 2 year-olds to 10.36 mm for 0-1 year-olds. Only 12% of the patients satisfied the criteria set by Keats and Lusted, while 100% satisfied Duncan’s criteria, 94% and 98% satisfied Wippold’s 1st and 2nd criteria respectively. &#x0D; Conclusion: All of the PVST criteria mentioned in Cummings’ Textbook of Otorhinolaryngology Head and Neck Surgery had a more than 90% accuracy compared to only 12% for those mentioned in Keats and Lusted’s Atlas of Roentgenographic Measurement. Therefore, we recommend the use of any criteria for PVST contained in the former over the latter. &#x0D; Keywords: Prevertebral soft tissue thickness, cervical vertebra

Multi-level spinal fusion and postoperative prevertebral thickness increase the risk of dysphagia after anterior cervical spine surgery

The present study aimed to determine the risk factors for dysphagia after anterior cervical spinal surgery. We reviewed clinical records of 45 patients after anterior cervical spinal surgery to identify the factors that influence dysphagia symptoms, and followed up the symptoms using a one-on-one telephone survey. The risk of dysphagia was greater in the anterior cervical discectomy and fusion group than in the anterior artificial disc insertion group, and in the group who underwent multi-level rather than single-level surgery. There were greater differences in prevertebral soft tissue thickness within 48 hours of surgery in patients with dysphagia than in patients without dysphagia at 1 month, 3 months, and 6 months after surgery, but these differences were not significant. The risk of dysphagia was significantly higher in patients who had their highest operative levels at C3 or C4 compared to those with their highest levels at C5 to C7.

Normal Thickness and Appearance of the Prevertebral Soft Tissues on Multidetector CT

Analysis of the prevertebral soft tissue (PVST) is helpful in detecting osseous and ligamentous injuries of the cervical spine. Because the standard of care has shifted from radiographs to multidetector CT (MDCT), a re-examination of the PVST on MDCT images is needed to establish normal values for thickness appropriate for this imaging technique. Thickness of the PVST was measured in 192 patients undergoing screening cervical spine MDCT with multiplanar reconstructions as part of a trauma protocol. Patients included in the study were not intubated, had an immobilized cervical spine, had normal findings on cervical spine CT, and did not have a diagnosis of osseous or soft-tissue cervical injury. Exclusion criteria included patients with a congenital or acquired (nondegenerative) abnormality of the cervical spine or PVST. The upper limits of normal for the thickness of the PVST were 8.5 mm at C1, 6 mm at C2, 7 mm at C3, 18 mm at C6, and 18 mm at C7. The upper limit of normal was not determined for C4 and C5 levels due to variable position of the esophagus and larynx. The smallest variability and calculated SDs were found at C2 and C3. The thickness of the PVST is important in the detection of underlying injuries to the cervical spine. We propose the obtained values as the upper limits of normal for PVST thickness on MDCT images in the adult population.