Morphological examination of abdominal vertebral bodies from grass carp using high-resolution micro-CT scans.

The vertebral column, a defining trait of all vertebrates, is organized as a concatenated chain of vertebrae, and therefore its support to the body depends on individual vertebral morphology. Consequently, studying the morphology of the vertebral centrum is of anatomical and clinical importance. Grass carp (GC) is a member of the infraclass Teleostei (teleost fish), which accounts for the majority of all vertebrate species; thus, its vertebral anatomical structure can help us understand vertebrate development and vertebral morphology. In this study, we have investigated the morphology and symmetry of the grass carp vertebral centrum using high-resolution micro-CT scans. To this end, three abdominal vertebrae (V9, V10, & V11) from eight grass carp were micro-CT scanned and then segmented using Dragonfly (ORS Inc.). Grass carp vertebral centrum conformed to the basic teleost pattern and demonstrated an amphicoelous shape (biconcave hourglass). The centrum's cranial endplate was smaller, less circular, and shallower compared to the caudal endplate. While the vertebral centrum demonstrated bilateral symmetry along the sagittal plane (left/right), the centrum focus was shifted dorsally and cranially, breaking dorsoventral and craniocaudal symmetry. The sum of these findings implies that the caudal aspect of grass carp vertebral centrum is bigger and more robust. Currently, we have no information whether this is due to nature, for example, differences in gene expression, or nurture, for example, environmental effect. As the vertebral parapophyses and spinous processes are slanted caudally, the direction of muscle action during swimming may create a gradient of stresses from cranial to caudal, resulting in a more robust caudal aspect of the vertebral centrum. Expanding our study to include additional quadrupedal and bipedal (i.e., human) vertebrae, as well as testing if these morphological aspects of the vertebrae are indeed plastic and can be affected by environmental factors (i.e., temperature or other stressors) may help answer this question.

Long-term effects of local radiotherapy on growth and vertebral features in children with high-risk neuroblastoma.

BACKGROUND: To evaluate the effects of local radiotherapy (RT) on growth, we evaluated the chronological growth profiles and vertebral features of children with high-risk neuroblastoma. METHODS: Thirty-eight children who received local photon or proton beam therapy to the abdomen or retroperitoneum between January 2014 and September 2019 were included. Simple radiography of the thoracolumbar spine was performed before and every year after RT. The height and vertical length of the irradiated vertebral bodies (VBs) compared with the unirradiated VBs (vertebral body ratio, VBR) were analyzed using the linear mixed model. Shape feature analysis was performed to compare the irradiated and unirradiated vertebrae. RESULTS: The follow-up was a median of 53.5 months (range, 21-81 months) after RT. A decline in height z-scores was mainly found in the early phase after treatment. In the linear mixed model with height, the initial height (fixed, p < 0.001), sex (time interaction, p = 0.008), endocrine dysfunction (time interaction, 0.019), and age at diagnosis (fixed and time interaction, both p = 0.002) were significant. Unlike the trend in height, the change in VBR (ΔVBR) decreased gradually (p < 0.001). The ΔVBR in the group that received more than 30 Gy decreased more than in the group that received smaller doses. In the shape feature analysis, the irradiated VBs changed to a more irregular surface that were neither round nor rectangular. CONCLUSION: The irradiated VBs in children were gradually restricted compared to the unirradiated VBs in long-term follow-up, and higher RT doses were significantly affected. Radiation-induced irregular features of VBs were observed.

Feature-based multimodal registration framework for vertebral pose estimation.

PURPOSE: The reliable estimation of the vertebral body posture helps to aid a safe and effective spine surgery. The proposed work aims to present an MR to X-ray image registration to assess the 3D pose of the vertebral body during spine surgery. The 3D assessment of vertebral pose assists in analyzing the position and orientation of the vertebral body to provide information during various clinical diagnosis conditions such as curvature estimation and pedicle screw insertion surgery. METHODS: The proposed feature-based registration framework extracted vertebral end plates to avoid the mismatch between the intensities of MR and X-ray images. Using the projection matrix, the segmented MRI is forward projected and then registered to the X-ray image using binary image matching similarity and the CMA-ES optimizer. RESULTS: The proposed method estimated the vertebral pose by registering the simulated X-ray onto pre-operative MRI. To evaluate the efficacy of the proposed approach, a certain number of experiments are carried out on the simulated dataset. CONCLUSION: The proposed method is a fast and accurate registration method that can provide 3D information about the vertebral body. This 3D information is useful to improve accuracy during various clinical diagnoses.

Radiological Outcomes of Re-tethering for Adolescent Idiopathic Scoliosis: A 2-to-5-year Follow-Up Case Series After Index Vertebral Body Tethering Failure.

PURPOSE: Vertebral Body Tethering (VBT) has been shown to have a less predictable outcome compared to spinal fusion in patients with adolescent idiopathic scoliosis (AIS). Tether breakage is a common mechanical event that sometimes leads to loss of correction. No data has been published that evaluates the outcome of re-tethering in patients who underwent revision surgery for failed VBT, which was the purpose of this study. METHODS: This is an analysis of a prospectively collected single center database of 290 patients who have had VBT. Patients for this study were included if they have had re-tethering after failed VBT and a minimum follow up of 24 months after index surgery as well as a minimum follow up of 12 months after revision surgery. Revision surgeries included tether exchange, tether reinforcement and/or mono- and bisegmental lateral fusion. Main outcome of interest was curve magnitude at latest follow up. RESULTS: 11 patients were identified who received VBT for 16 curves of which 13 curves have had failed index surgery. Mean follow up from index surgery was 40 months, time between index and revision surgery was 22 months and latest follow up after revision surgery 19 months. Re-tethering resulted in an additional correction of 42% for thoracic and 63% for thoracolumbar curves. These results remained clinically stable with only minor loss of correction at final follow up. No patient underwent or was indicated for spinal fusion. CONCLUSION: Re-tethering is feasible and able to achieve additional correction and a sustainable result.

Early-term outcome of apical fusion with vertebral body tethering for thoracolumbar curves in adolescent idiopathic scoliosis: a preliminary study.

INTRODUCTION: Vertebral body tethering (VBT) has become an alternative option for select patients with idiopathic scoliosis. However, studies have shown a high number of tether breakages, specifically after thoracolumbar (TL) VBT, that can have a negative impact on the outcome, when the breakage occurs within the first year after surgery. In order to overcome this problem, we have started to apply an apical fusion (AF) in combination with TL VBT for select patients. This study aims to analyze the outcome after AF plus VBT. METHODS: This is a retrospective single surgeon's data analysis. All patients were included who have had TL VBT after January 2022 and a follow-up of 12 months. Patients were grouped based on whether they only had VBT or VBT + AF. RESULTS: Twenty-five patients were analyzed (15 VBT, 10 VBT + AF). Both groups showed a significant curve correction for thoracic and TL curves. Minor loss of correction was observed in both groups. A significant difference was seen regarding early tether breakages, which were found in 60% of VBT patients and 10% of VBT + AF patients. CONCLUSION: The preliminary data shows a significant reduction of early tether breakages when TL VBT is applied in combination with AF.

The efficacy of anterior vertebral body tethering in lenke type 6 curves for adolescent idiopathic scoliosis.

PURPOSE: Spinal fusion is the standard treatment for severe forms of adolescent idiopathic scoliosis (AIS). However, with the lowest instrumented vertebra that is usually located at L3 or L4, patients are prone to develop adjacent segment degeneration in the long term. Vertebral body tethering (VBT) as motion preserving technique has become an alternative for select patients with AIS. Several studies have presented the outcome after thoracic VBT but no study has analyzed the outcome after VBT for Lenke type 6 curves. METHODS: This is a retrospective single center data analysis of patients who have had bilateral VBT for Lenke type 6 curves and a minimum follow up of 24 months. Radiographic analysis was performed on several time points. Suspected tether breakages were additionally analyzed with respect to location and time at occurrence. RESULTS: 25 patients were included. Immediate thoracic curve correction was 55.4% and 71.7% for TL/L curves. Loss of correction was higher for TL/L curves and resulted in a correction rate of 48.3% for thoracic curves and 48.9% for TL/L curves at 24 months post-operatively. 22 patients were suspected to have at least one segment with a tether breakage. Three patients required a re-VBT but no patient received posterior spinal fusion. CONCLUSION: Bilateral VBT for Lenke type 6 curves is feasible and shows a significant curve correction for thoracic and TL/L curves at a minimum of 24 months post-operatively. Tether breakage rate and loss of correction remain an unfavorable observation that needs to be improved in the future.

Delayed hemothorax after anterior vertebral body tethering in adolescent idiopathic scoliosis: a case report.

PURPOSE: The aim of this case report is to report that delayed hemothorax is possible after anterior vertebral body tethering (aVBT) and to illustrate the course of treatment. METHODS: We present a 15-year-old boy with adolescent idiopathic scoliosis who underwent an anterior thoracoscopic assisted vertebral body tethering who developed a massive right-sided hemothorax 12 days post-operatively. A chest tube was placed to drain the hemothorax and later required embolectomy with tissue plasminogen activator (TPA) to drain the retained hemothorax. RESULTS: At 1 month follow up post discharge the patient was asymptomatic, and radiograph did not demonstrate evidence of residual hemothorax and scoliosis. We have followed this patient for 5 years postoperative and he continues to do well clinically and radiographically. CONCLUSIONS: Pulmonary complications are a known drawback of anterior thoracoscopic spinal instrumentation. Delayed hemothorax is possible after aVBT. In the case of a retained hemothorax, chest tube treatment with TPA is a safe and effective method of embolectomy.

The clinical effect of different vertebral body height restoration rates after percutaneous kyphoplasty for osteoporotic vertebral compression fractures.

OBJECTIVE: This study aimed to evaluate the clinical effect of different vertebral body heights restoration rate after percutaneous kyphoplasty (PKP) for the treatment of osteoporotic vertebral compression fractures (OVCF). METHODS: The patients were divided into two groups according to the height restoration rate of the anterior edge of the vertebral body fracture after PKP operation using X-Ray imaging. The group A was below 80%, and the group B was above 80%. Clinical preoperative and postoperative efficacy (1st day, 1st month, 6th month, and 12th month after surgery) were evaluated according to VAS, Oswestry Disability Index(ODI), Quality of Life Questionnaire of the European Foundation for Osteoporosis(QUALEFFO), and Back Pain Life Disorder Questionnaire(RQD). Simultaneously, the preoperative and postoperative local Cobb angles and changes in the injured vertebrae in the two groups were calculated and analyzed. RESULTS: The postoperative Cobb angle in group A was significantly higher than that in group B. The correction rate in group B was significantly better than that in group A. The VAS, ODI, QUALEFFO, and RQD scores of group B patients were significantly lower than those of patients in group A at each follow-up time point. The correlation coefficients of vertebral body height restoration rate and VAS, ODI, QUALEFFO, and RQD scores at the last follow-up were - 0.607 (P < 0.01), -0.625 (P < 0.01), -0.696 (P < 0.01), and - 0.662 (P < 0.01), respectively. CONCLUSIONS: The results of the correlation analysis between the vertebral body height restoration rate and the above clinical efficacy scores show that increasing the vertebral body anterior height restoration rate is beneficial for pain relief and improves the clinical efficacy of patients. Simultaneously, improving the height restoration rate of the anterior edge of the vertebral body and restoring the normal spinal structure is beneficial for reducing the incidence of refracture of the adjacent vertebral body.

Finite element analysis of precise puncture vertebral augmentation in the treatment of different types of osteoporotic vertebral compression fractures.

BACKGROUND: Osteoporosis vertebral compression fracture (OVCF) secondary to osteoporosis is a common health problem in the elderly population. Vertebral augmentation (VA) has been widely used as a minimally invasive surgical method. The transpedicle approach is commonly used for VA puncture, but sometimes, it is limited by the anatomy of the vertebral body and can not achieve good surgical results. Therefore, we propose the treatment of OVCF with precise puncture vertebral augmentation (PPVA). This study used finite element analysis to explore the biomechanical properties of PPVA in the treatment of osteoporotic vertebral compression fractures (OVCFs) with wedge, biconcave, and collapse deformities. METHOD: Three-dimensional finite element models of the fractured vertebral body and adjacent superior and inferior vertebral bodies were established using Computed Tomography (CT) data from patients with OVCF, both before and after surgery. Evaluate the stress changes of the wedged deformed vertebral body, biconcave deformed vertebral body, collapsed deformed vertebral body, and adjacent vertebral bodies before and after PPVA. RESULT: In vertebral bodies with wedge deformity and collapsed deformity, PPVA can effectively reduce the stress on the vertebral body but increases the stress on the vertebral body with biconcave deformity. PPVA significantly decreases the stress on the adjacent vertebral bodies of the wedge deformed vertebral body, and decreases the stress on the adjacent superior vertebral body of biconcave deformity and collapsed deformed vertebral bodies, but increases the stress on the adjacent inferior vertebral bodies. PPVA improves the stress distribution of the vertebral body and prevents high-stress areas from being concentrated on one side of the vertebral body. CONCLUSION: PPVA has shown positive surgical outcomes in treating wedge deformed and collapsed deformed vertebral bodies. However, its effectiveness in treating biconcave vertebral body is limited. Furthermore, PPVA has demonstrated favorable results in addressing adjacent superior vertebral body in three types of fractures.

Multilevel Vertebral Body Osteonecrosis in an Adult Patient: A Rare Case with Review of Literature.

Osteonecrosis, characterized by ischemic bone injury leading to cell death and bone resorption, manifests in various anatomical sites due to multiple etiologies such as radiotherapy and medications. While certain sites like the femoral head and jaw have garnered attention, vertebral body osteonecrosis remains less explored and lacks a standardized classification system. This report presents a unique case of a 52-year-old woman undergoing chemotherapy for diffuse large B-cell lymphoma who developed multilevel vertebral body osteonecrosis, a rare occurrence in English medical literature. The patient presented with fever, abdominal pain, and lymphoid malignancy markers, initiating chemotherapy with the rituximab, cyclophosphamide, vincristine, and prednisolone (R-CVP) regimen. During treatment, she experienced breathing difficulties and back pain, prompting imaging studies revealing extensive osteonecrosis affecting multiple vertebrae and other skeletal sites. Various factors, including chemotherapy, human immunodeficiency virus (HIV) therapy, trauma, and others, contribute to vertebral body necrosis. While osteonecrosis in lymphoma patients is rare, chemotherapy-induced marrow necrosis can lead to bone involvement. Vertebral bodies, especially their anterior portions, are susceptible due to limited blood supply. The presence of an intravertebral vacuum cleft on radiographs is pathognomonic for osteonecrosis, while magnetic resonance imaging (MRI) reveals hypointense areas and fluid collections. This case underscores the complexity of diagnosing and managing multilevel vertebral body osteonecrosis, exacerbated by the lack of standardized protocols. The interplay between disease processes and treatment modalities complicates decision-making, emphasizing the need for further research to establish optimal diagnostic and treatment guidelines. In conclusion, this case sheds light on a rare manifestation of osteonecrosis in a lymphoma patient, highlighting the challenges in diagnosis and management. Further research is warranted to enhance understanding and improve outcomes for patients with this debilitating condition.

[Imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae].

Objective: To analyze the imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae in pediatric patients. Methods: The data of 13 patients with hemivertebrae locating in the lumbar spine symmetrically were retrospectively analyzed, and all the patients were treated in Beijing Children's Hospital from January 2015 to September 2021. The mean age of the patients was 6.2 (2.9, 9.3) years. There were 8 males and 5 females. The data of coronal/sagittal plane including segmental Cobb angle, cranial/caudal compensatory curve, thoracic kyphosis, thoracolumbar kyphosis, sacral obliquity, and lumbar lordosis were recorded through long cassette spinal radiographs. Associated anomalies and the relationship between hemivertebrae and posterior component were recorded through computerized tomography (CT) and magnetic resonance imaging (MRI). All the patients received surgery, and their pre-and postoperative imaging data were compared. Results: A total of 26 hemivertebraes were found, in which 80.8% (21/26) located below L2. Hemivertebraes in 10 patients were separated by a mean 1-2 normal vertebrae. Most hemivertebraes along with the corresponding posterior component were unison (21/26, 80.8%). The Cobb angles of cranial compensatory curve (13.9°±7.2°) was more serious than that of caudal compensatory curve (5.5°±5.0°)(P=0.04). The lumbar lordosis and thoracic kyphosis was 20.2°±15.0° and 18.7°±9.2°, respectively. Six patients complicated with sacral obliquity, while 7 patients complicated with thoracolumbar lordosis. Associated anomalies were found in 6 (46.2%) patients through CT and MRI. Eleven patients received one-or two-stage posterior hemivertebrae resection with short segmental fusion, and 2 patients received one-stage hemivertebrae resection with long segmental fusion. All the surgery were completed successfully without serious complications such as nerve injury, infection, and implant failure. The mean follow-up period was (42.4±10.2) months. At the last follow-up point, the correction rate of segmental Cobb angle and cranial compensatory curve was 83.3%±15.6% and 38.1%±10.4%, respectively, showing significant improvement (P<0.05). Although the caudal compensatory curve, sacral obliquity, and thoracic kyphosis improved after surgery, the data showed no significant difference compared to that before surgery. Thoracolumbar lordosis in all patients were corrected. Conclusions: Most hemivertebraes in such spinal deformity locate in lower lumbar region with a high incidence of anomalies. Individualized treatment based on patients' condition is essential for the complicated spinal deformity.

Using inverse finite element analysis to identify spinal tissue behaviour in situ.

In computational modelling of musculoskeletal applications, one of the critical aspects is ensuring that a model can capture intrinsic population variability and not only representative of a "mean" individual. Developing and calibrating models with this aspect in mind is key for the credibility of a modelling methodology. This often requires calibration of complex models with respect to 3D experiments and measurements on a range of specimens or patients. Most Finite Element (FE) software's do not have such a capacity embedded in their core tools. This paper presents a versatile interface between Finite Element (FE) software and optimisation tools, enabling calibration of a group of FE models on a range of experimental data. It is provided as a Python toolbox which has been fully tested and verified on Windows platforms. The toolbox is tested in three case studies involving in vitro testing of spinal tissues.

Sagittal wedging of intervertebral discs and vertebral bodies in the cervical spine and their associations with age, sex and cervical lordosis: A large-scale morphological study.

Many recent studies have focused on the functional and clinical importance of cervical lordosis. However, there is little accurate knowledge of the anatomical parameters that constitute cervical lordosis (i.e., the sagittal wedging angles of intervertebral discs and vertebral bodies) and their associations with age and sex. Standing lateral cervical radiographs of 1020 subjects (424 males, 596 females) with a mean age of 36.6 ± 17.0 years (range 7-95 years) were evaluated retrospectively. Cervical lordosis, the sum of intervertebral disc wedging angles from C2/C3 to C6/C7 and the sum of vertebral body wedging angles from C3 to C7 were measured. The sum of intervertebral disc wedging and the sum of vertebral body wedging were 20.6° ± 14.7° and -12.8° ± 10.3°, respectively. The sum of intervertebral disc wedging increased significantly with age and was significantly greater in males than females, whereas there was no sex-related difference in the sum of vertebral body wedging. The sum of intervertebral disc wedging was negatively correlated with sum of vertebral body wedging. Wedging of discs contributed to C2-C7 cervical lordosis more significantly than wedging of vertebral bodies. There were moderate positive correlations between cervical lordosis and intervertebral disc wedging angles at C3/C4, C4/C5 and C5/C6; weak correlations were observed at C2/C3 and C6/C7. This study constitutes the largest currently available analysis comprehensively documenting the anatomical characteristics of sagittal wedging of intervertebral discs and vertebral bodies in the cervical spine. The findings could improve understanding of the internal architecture of cervical lordosis among clinicians.

Basivertebral foramina of true vertebrae: morphometry, topography and clinical considerations.

PURPOSE: Basivertebral foramina (BVF) are openings of the posterior wall of vertebral body (VB) that lead to basivertebral canals (BVC), where homonymous neurovascular bundle courses. BVF and BVC are implicated with spinal fractures, vertebral augmentation and basivertebral nerve radiofrequency ablation. Despite their essential clinical impact, knowledge of BVF precise anatomy is scarce. The current study describes in detail the BVF typical morphological and topographical anatomy, morphometry and variants. METHODS: In total, 1561 dried true vertebrae of 70 Greek spines of known gender and age were examined. BVF number, location, shape and size (in foramina > 1 mm), BVF distance from VB rims and pedicles, as well as VB morphometry (diameters, heights and distance between pedicles) were studied. Ten spines were re-examined by computed tomography and BVC depth and shape were recorded. Correlations and differences were statistically analyzed. RESULTS: C1 lack BVF (3.4%). One BVF was found in 45.1%, two in 36.9%, three in 3.8% and four BVF in 0.6%. Multiple small (< 1 mm) foramina were observed in 10.1%. Asymmetry was detected in 12.3%. C2 and T10-L1 presented typical pattern, whereas C3 and T2 had the greatest variability. BVF were significantly closer to the upper rim in C2 and T10-L4 and to the lower rim in C7-T4, T6-T8 and L5. The mean BVC depth was 12-21.8% of the VB anteroposterior diameter. CONCLUSION: BVF number, shape, size and topography are described, in detail, per vertebral level. The provided morphological classification and the created cumulative BVF topographic graphs should assist in clinical practice and surgery.

Multi-level sagittally cleft vertebrae: a case report and review of the literature.

The term "sagittal cleft vertebra" (SCV) denotes a rare embryologically derived longitudinal defect within the vertebral body, which is clinically and radiologically challenging to diagnose in isolation. This defect results in two hemivertebrae, which ossify discordantly, ultimately leading to a sagittal cleft through the vertebral body. Often presenting with low back pain or concomitant with an associated syndromic illness, SCV is often found incidentally and can mimic vertebral compression fractures radiographically. Treatment of SCV has largely been conservative and symptomatic. With only 109 reported cases in the current literature, we present a unique case of multiple SCV throughout the thoracolumbar region in an adolescent patient. We performed a review of the literature to identify published cases of SCV to date. We searched PUBMED using the terms "sagittal cleft vertebrae", "butterfly vertebrae", and "anterior rachischisis". Abstracts were screened for reports specifically involving original cases of SCV. Given the well-established association with syndromic illnesses, finding an SCV warrants further investigation for other abnormalities of the musculoskeletal, cardiac, and genitourinary systems. Complex management strategies are rare unless the SCV is associated with an aberrant syndrome, disc herniation or severe musculoskeletal abnormality, or symptomatic disc herniation requiring surgical management. Further studies should focus on uncovering the genetic markers leading to the cleft vertebral bodies, with a focus on early screening and monitoring of patients who could be predisposed to the condition.

T1-weighted Dynamic Contrast-enhanced MRI to Differentiate Nonneoplastic and Malignant Vertebral Body Lesions in the Spine.

Background Dynamic contrast agent-enhanced (DCE) perfusion MRI may help differentiate between nonneoplastic and malignant lesions in the spine. Purpose To investigate the correlation between fractional plasma volume (Vp), a parameter derived from DCE perfusion MRI, and histopathologic diagnosis for spinal lesions. Materials and Methods In this retrospective study, patients who underwent DCE perfusion MRI and lesion biopsy between May 2015 and May 2018 were included. Inclusion criteria were short time interval (<30 days) between DCE perfusion MRI and biopsy, DCE perfusion MRI performed before biopsy, and DCE perfusion MRI performed at the same spine level as biopsy. Exclusion criteria were prior radiation treatment on vertebrae of interest, poor DCE perfusion MRI quality, nondiagnostic biopsy, and extensive spinal metastasis or prior kyphoplasty. One hundred thirty-four lesions were separated into a nonneoplastic group (n = 51) and a malignant group (n = 83) on the basis of histopathologic analysis. Two investigators manually defined regions of interest in the vertebrae. DCE perfusion MRI parameter Vp was calculated by using the Tofts pharmacokinetic two-compartment model. Vp was quantified, normalized to adjacent normal vertebrae, and compared between the two groups. A Mann-Whitney U test and receiver operating characteristic analysis was performed to verify the difference in Vp between the nonneoplastic and malignant groups. Reproducibility was assessed by calculating the Cohen κ coefficient. Results One hundred patients (mean age, 65 years ± 11 [standard deviation]; 52 men) were evaluated. Vp was lower in nonneoplastic lesions versus malignant lesions (1.6 ± 1.3 vs 4.2 ± 3.0, respectively; P < .001). The sensitivity of Vp was 93% (77 of 83; 95% confidence interval [CI]: 85%, 97%), specificity was 78% (40 of 51; 95% CI: 65%, 89%), and area under the receiver operating characteristic curve was 0.88 (95% CI: 0.82, 0.95). Cohen κ coefficient suggested substantial agreement in both intra- (κ = 0.72) and interreader (κ = 0.70) reproducibility. Conclusion This study indicated that dynamic contrast agent-enhanced perfusion MRI parameter, fractional plasma volume, was able to differentiate between nonneoplastic spinal lesions and malignant lesions. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Haller in this issue.

Prevalence and Characterization of Interaction of Retrievable Inferior Vena Cava Filters with the Spine in Patients Undergoing Complex Filter Removal.

PURPOSE: To examine spinal interaction types and prevalence of inferior vena cava (IVC) filters in patients presenting for complex filter removal. MATERIALS AND METHODS: The records of 447 patients presenting for complex removal of IVC filters were reviewed, including patient demographics, IVC filter dwell time, filter fracture status, and computed tomography (CT) evidence of filter interaction with the spine. Spinal interaction was defined as a filter strut touching or penetrating into the vertebral body or disc. Patients with evidence of filter penetration and spinal interaction had abdominal CT that preceded filter removal assessed by 2 interventional radiologists to categorize the type of spinal interaction, including bony reaction and osteophyte formation. RESULTS: CT evidence of spinal interaction by the filter was found in 18% of patients (80/447). Interaction with the spine was more common in single point of fixation filters than filters with rails (P = .007) and was more likely in filters with round wires than flat wires (P = .0007). Patients with interaction had longer dwell times (mean [SD] 5.7 [4.46] y) compared with patients without interaction (mean [SD] 3.2 [3.85] y); this relationship was significant (P < .0001). Women were more likely than men to experience filter/spine interaction (P = .04). Filters with spinal interaction were more likely to be fractured (P = .001). Filter interaction was found in 38% (30/78) of patients with symptoms, including chest and back pain, compared with 14% (50/369) of patients without symptoms (P < .0001, odds ratio 3.99). CONCLUSIONS: Retrievable IVC filters may interact with the spine. These interactions are associated with longer filter dwell times, female sex, and round wire filter construction.

Trapezoidal Vertebral Body and Spine-Pelvis Sagittal Alignment in Patients with Lumber Spondylolisthesis.

BACKGROUND Trapezoidal changes of the vertebral body are more common in patients with lumbar spondylolisthesis than in others. However, we lack an understanding of factors predisposing to the development of a marked trapezoidal deformity. Also, no associations between a trapezoidal vertebrae (TV) and spine-pelvis sagittal parameters have been previously reported. MATERIAL AND METHODS A total of 73 subjects with lumbar spondylolisthesis were enrolled and we collected their clinical data. Vertebral body parameters and spine-pelvis sagittal alignment parameters were measured via lumbar spine X-ray. Using the lumbar index (LI), patients were divided into a TV group (LI >0.8, n=24) and a control group (LI >0.8, n=49). The clinical data and spine-pelvic sagittal parameters of the 2 groups were compared using the t test or chi-squared test. Pearson's correlation analysis and multiple linear regression were used to determine relationships among the parameters. RESULTS The TV and control groups differed significantly in terms of the slipped segment, extent of slippage, intervertebral disc height (IDH), and sagittal parameters (all P<0.05). Pearson's correlation analysis and multiple linear regression analysis showed that the slipped segment (r=-0.606), extent of slippage (r=-0.660), and IDH (r=0.698) were risk factors for the development of a TV body. Also, vertebral trapezoidal deformation was closely associated with sagittal parameters. CONCLUSIONS The vertebral body affected by lumbar spondylolisthesis exhibits a trapezoidal change closely associated with the slipped segment, the extent of slippage, and IDH. The TV group exhibited greater pelvic incidence values and lumbar lordosis, which may have caused wedging of the slipped vertebra.

Hounsfield units of the vertebral body and pedicle as predictors of pedicle screw loosening after degenerative lumbar spine surgery.

OBJECTIVE: The authors aimed to compare the efficacy of lumbar vertebral body Hounsfield units (HUs) and pedicle HUs at predicting pedicle screw loosening. METHODS: The authors retrospectively assessed 143 patients with L3-5 instrumentation. The patients were classified into one of two groups based on the status of their L3 screws (a screw loosening group or a control group). The pedicle HUs and vertebral HUs of L3 were measured using preoperative lumbar CT scans, and the pedicle HUs were measured in two ways: by excluding or by including cortical bone. RESULTS: The screw loosening rate was 20.3% (n = 29/143) at the 12-month follow-up. The vertebral body HUs and pedicle HUs in the screw loosening group were lower than those in the control group (vertebral body group: 98.6 HUs vs 121.4 HUs, p < 0.001; pedicle excluding cortical bone: 208.9 HUs vs 290.5 HUs, p = 0.002; pedicle including cortical bone: 249.4 HUs vs 337.5 HUs, p < 0.001). The pedicle HUs tended to have a higher area under the receiver operating characteristic curve value in predicting screw loosening, compared with that of vertebral body HUs, but the difference was not statistically significant (p > 0.05). Among patients with low vertebral body HUs of ≤ 130, the loosening rate was much lower in patients with pedicle HUs of ≤ 340 than in those with pedicle HUs of > 340 (31.0% vs 13.0%, respectively; p < 0.05). CONCLUSIONS: Vertebral body HUs alone are insufficient to accurately evaluate the risk of pedicle screw loosening. Therefore, it is important to collect both the pedicle HU and vertebral body HU measurements for surgical planning.

CT validation of SVC-RA junction location for pediatric central line placement: is vertebral bodies below the carina accurate?

PURPOSE: The key landmark for tip position of a central venous catheter (CVC) is the SVC-RA junction. In adults, localization of the SVC-RA junction may be assessed as a function of vertebral body units (VBU) below the carina during CVC placement. We investigated the relationship between the SVC-RA junction and the carina in children. MATERIALS AND METHODS: 584 CT scans of 0-18 years were analyzed. The carina was marked automatically by software while the SVC-RA junction and vertebrae were marked manually. The SVC-RA junction to carina (JC) distance was the primary study measurement reported in both VBU and mm. RESULTS: The data show an average JC distance of 1.25 VBU for 0-1 year, 1.27 VBU for 1-4 years, 1.34 VBU for 4-9 years, 1.53 VBU for 9-15 years, and 1.64 VBU for 15-18 years. A positive relationship between weight and JC distance was also demonstrated. CONCLUSION: JC distance is a useful predictor of SVC-RA junction location in children. Significant relationships were shown between JC distance and both age and weight. Due to small differences between age groups, however, average JC distance for all comers (1.48 VBU, 95% CI 0.7 - 2.3) can be used for SVC-RA junction identification in CVC placement.