Spine CT Research Articles

Entry point and screw path study of second sacral alar-iliac screw trajectory in spinal pelvic fixation under O-arm navigation

Objective: To explore the feasibility of using the entry point and screw path parameters of sacroiliac (S2AI) screws inserted under O-arm 3D computer navigation as a reference for freehand screw insertion in patients with degenerative spinal deformities. Methods: A retrospective analysis was conducted on the clinical data of 66 patients with degenerative spinal deformities who received S2AI screw fixation assisted by the O-arm 3D computer navigation system at Nanjing Drum Tower Hospital Affiliated with Nanjing University Medical School from January 2017 to April 2022. The patients included 6 males and 60 females, with a mean age of (64.3±5.9) years. Preoperatively, the entry point was set as the intersection of 1 mm from the outer and lower edges of the S1 foramen, adjusted intraoperatively by navigation, and verified postoperatively by full spinal CT scans and 3D reconstructions. Using the S1 screw entry point as the origin, the position of the bilateral S2AI screw entry points, tailward angulation (SA), outward angulation (TA), and vertical distance from the entry point to the skin (SD) were measured on postoperative CT 3D images. The accuracy of S2AI screw placement and any intraoperative and postoperative complications were recorded. Differences in entry point coordinates and screw path parameters between the left and right sides were compared. The intraclass correlation coefficient (ICC) was used to assess intra-observer and inter-observer agreement. Results: The coordinates and screw path parameters for the S2AI screws placed using the O-arm navigation demonstrated good intra-observer and inter-observer consistency (ICC>0.75). The left entry point was located (8.08±1.39) mm laterally and (24.47±2.20) mm caudally from the S1 entry point, while the right entry point was (8.09±1.41) mm laterally and (24.40±2.54) mm caudally, with no significant difference between the left and right sides (both P>0.05). The left TA was 46.33°±3.44°, SA was 39.14°±6.12°, and SD was (60.38±13.37) mm; the right TA was 46.37°±3.41°, SA was 39.59°±5.89°, and SD was (60.30±12.24) mm, with no significant differences between the left and right parameters (all P>0.05). There was no significant neurovascular complications intraoperatively or two weeks postoperatively, with a screw insertion accuracy of 97.7% (129/132). Conclusions: In the fixation of the pelvis in degenerative spinal deformities, the use of O-arm navigation-assisted S2AI screw insertion has a high accuracy rate. It is recommended that for freehand screw insertion, the entry point should be located 24 mm caudally and 8 mm laterally from the outer and lower edges of the superior articular process of S1, with an TA of approximately 46° and a SA of approximately 39°.

Assessment of cervical spine CT by an image quality audit using qualitative and quantitative methods.

To study the feasibility and assess the correlation of qualitative and quantitative methods for an image quality (IQ) audit of a Cervical spine CT. Five radiologists retrospectively performed a blinded visual grading analysis (VGA) on 20 studies (10 from Protocol 1 and 10 from Protocol 2), using the RANZCR CT IQ Self-Audit worksheet. A Visual Grading Analysis Score (VGAS) and Area under the curve using Visual Grading Characteristics (AUCVGC) were the figures of merit. Quantitative metrics for noise and contrast were correlated to the qualitative assessment. No statistically significant difference was observed in the IQ, VGASProtocol1 = 0.65, 95% CI [0.54, 0.75] and VGASProtocol 2 = 0.73, 95% CI [0.67, 0.79] and AUCVGC = 0.548, 95% CI [0.40, 0.69]. Protocol 2 indicated a statistically significant average dose reduction of 35% in CTDIvol (P = 0.020) and a higher noise; however, the difference was statistically insignificant. There was a moderate correlation between the manual noise measurements in soft tissue and air (P = 0.035) and a strong correlation between the manual and automated noise measurements (P < 0.001). The contrast resolution-based quantitative parameter, EdgeGradientSoft, correlated to the qualitative scores (P = 0.031). Validated VGA tools can be used for IQ audits; however, tailoring the image criteria and rating scale to the clinical practice is suggested. The use of contrast-based IQ metrics showed encouraging results, and further larger-scale studies are needed to explore their potential use in quality management.

Opportunistic Bone Mineral Density Measurement Using Photon-Counting Detector CT Spectral Localizer Images: A Prospective Study.

Background: Spectral localizer images from photon-counting detector (PCD) CT can be used for bone mineral density (BMD) evaluation given their 2D-projectional nature and material decomposition capability. As all CT examinations include localizer images, this approach could allow opportunistic osteoporosis screening in patients undergoing clinically indicated imaging by PCD CT. Objective: To assess the utility of PCD-CT spectral localizer images for opportunistic derivation of area BMD (aBMD) values and T-scores, using dual-energy X-ray absorptiometry (DXA) as the reference standard. Methods: This prospective study included patients ≥18 years old scheduled for clinically indicated lumbar spine CT between October 2023 and February 2024 and who underwent DXA within the 13 prior months or were scheduled for DXA within the subsequent 13 months. Participants underwent lumbar spine CT by PCD CT including spectral localizer images. Lumbar spine aBMD was extracted from clinical DXA reports. ROIs were placed on lumbar vertebral bodies and background soft tissues to extract areal densities from spectral localizer images using material decomposition; areal densities were used to derive lumbar spine aBMD values. The aBMD values were used to derive T-scores, which were classified as representing normal (≥-1) or abnormal (<-1) bone mass. DXA-derived and PCD-CT derived measurements were compared. Results: The study included 51 participants (mean age: 62 years [range, 28-83 years]; 31 female, 20 male). Mean DXA-derived T-score was 0.39±1.64; mean PCD-CT derived T-score was 0.28±1.77 (p=.29). Lin's concordance correlation coefficient between DXA-derived and PCD-CT T-scores was 0.90. The difference between DXA-derived and PCD-CT derived T-scores showed a small correlation with patient age (r=-0.13), absolute interval between DXA and PCD CT (r=.15), and BMI (r=0.28); this difference in scores did not show a significant difference between male and female patients (0.08 vs 0.13, respectively; p=.81). PCD-CT T-scores had sensitivity of 97%, specificity of 71%, PPV of 90%, and NPV of 91% for detecting abnormal bone mass using DXA-derived T-scores as the reference standard. Conclusion: PCD-CT spectral localizers showed clinical utility for deriving aBMD values and, consequently, T-scores. Clinical Impact: The T-score derived from PCD-CT spectral localizers may serve as an opportunistic screening tool for low bone mass and osteoporosis.

7002 Building Poor Bone, A Rare Presentation Of Skeletal Fluorosis

Abstract Disclosure: C. Pham: None. J.S. Lopresti: None. Skeletal fluorosis is a rare disease associated with osteosclerosis and fractures. Case: 26 year old male presented with a history of multiple traumatic fractures but no childhood or family history of fractures. Initial labs revealed a corrected calcium of 8.1 mg/dL (8.5-10.3), ALP 1,504 U/L (40-129), PTH 131 pg/ml (15-65), 25-OH D 14 ng/ml (30-100), PO4 3.7 mg/dl (2.5-4.5) and normal creatinine. X-Rays demonstrated osteosclerosis and cortical expansion of bone and nuclear bone scan demonstrated diffuse increased uptake. Further history revealed huffing of computer inhalants (10 cans daily) for years. Due to these findings, urine fluoride 16.88 mg/L (0.20-3.20 mg/L) and serum fluoride 0.40 mg/L (&amp;lt;0.05 mg/L) were obtained and vitamin D was started. 4 months later, his vitamin D level improved to 21 while calcium levels normalized despite ongoing inhalant use. ALP (878) and PTH (92) continued to be elevated albeit at improved levels. Conclusion: Exposure to fluoride leads to a rare condition called skeletal fluorosis causing accelerated osteogenesis and bone turnover leading to weak bone. Symptoms include bony pain, fractures, and osteosclerosis on radiographs. Differential diagnosis includes other conditions associated with osteosclerosis such as Paget’s disease and myelofibrosis. However, diffuse osteosclerosis and vertebral osteophytosis are noted only in skeletal fluorosis compared to other potential causes, though our patient did not have a CT spine done to assess for osteophytes. Biochemical studies can include hypocalcemia and hyperparathyroidism. It is thought that low calcium intake contributes to the hyperparathyroidism. Elevated serum and urine fluoride levels are also diagnostic and can persist for months after cessation of fluoride intake. Sodium fluoride has been posited as a treatment for osteoporosis due to its tremendous ability to build bone; however, the quality of bone made is poor leading to unacceptable fracture rates. Skeletal fluorosis should be suspected in any patient with history of diffuse osteosclerosis and hyperparathyroidism; and vitamin D supplementation should be initiated. In our case, hypocalcemia and PTH levels were improved despite active inhalant use after vitamin D supplementation. This suggests that Vitamin D deficiency and fluoride may be two independent driving factors in hyperparathyroidism in patients with fluorosis. Increased calcium absorption with vitamin D provides therapeutic benefit in both cases. Presentation: 6/1/2024

Differences in Cervical Spine Fractures in Patients Younger or Older Than 65 Years of Age: Implications for the Canadian C-Spine Rule.

There has been a distinction made in the 2001 Canadian C-Spine Rule regarding patients 65 and older and younger than 65 years of age as far as indications for cervical spine CT scanning. We sought to determine if there are differences in the symptoms, mechanisms of injury, fracture locations, and types that are still relevant in 2024. The institutional review board approved this retrospective study of cervical spine CT emergency department results from 2 hospitals in our health system after reviewing 5 years of data in patients experiencing trauma. In addition to the primary variable of age (younger than 65 years and 65 years and older), we looked at injury mechanism, fracture types, sites, symptoms, and operative or medical treatments. Because the demographics of our home site is different from most towns in the United States, we provide race/ethnicity data. Of 21,986 cervical spine CTs, 190/9455 (2.0%) participants 65 years of age and older and 199/12,531 (1.6%) participants younger than 65 years of age had fractures (total, 389/21,986, 1.8%). There were more cases of falls from standing (106, 55.8%) and falls from a height (46, 4.2%) in those 65 years and older and this mechanism was associated with a higher risk of C1 and C2 fractures (52, 27.4%; and 78, 41.1%, respectively). Among the C1 fractures, anterior and posterior arch fractures predominated (37, 19.5%). For C2 fractures, types 2 and 3 odontoid fractures (39, 20.5%; and 12, 6.3%) were more common in the older cohort. Motor vehicle collisions were more common in the younger cohort (89, 44.7%), and they were associated with more C5-C7 fractures (47, 23.6%; 60, 30.2%; and 66, 33.2%, respectively) including the facets (49, 24.6%), spinous processes (31, 15.6%), and transverse processes (52, 26.1%). Overall, the rates of instability, surgical intervention, and asymptomatic fractures were similar in the 2 age groups. Cervical spine fractures appear in about 1.8% of the CT scans performed in a busy emergency department environment. Fractures in the elderly occur more commonly due to falls, are located at C1 and C2, and may involve ligamentous injuries. Younger patients incur trauma more commonly due to motor vehicle collisions, and they are more likely to affect the posterior elements, especially C5-C7. The differences in trends for fractures in the 65 years of age and older and younger than 65 years of age groups have persisted since the Canadian C-Spine Rule 1996-1998 data were collected.

Psoas muscle cross sectional area relates to bone density and microarchitecture in candidates for spine fusion surgery

Prior studies demonstrate that muscle and bone health are integrally related, and both independently impact orthopedic surgery outcomes. However, relationships between bone density, in vivo microarchitecture, and muscle area have not been previously investigated in orthopedic surgery patients. This study assessed associations between psoas cross sectional area (CSA), bone mineral density (BMD), and microstructure in a cohort undergoing spine fusion. Pre-operatively, bilateral psoas CSA was measured on axial lumbar spine CT in the L3-L4 disc space. To adjust for body size, Psoas Muscle Index (PMI) was calculated (CSA divided by the square of patient height). High resolution peripheral quantitative CT (HR-pQCT, XtremeCT2) assessed volumetric BMD (vBMD), cortical (Ct) and trabecular (Tb) microarchitecture at the distal radius and tibia. Areal BMD (aBMD) was measured by DXA at the lumbar spine (LS), total hip (TH), femoral neck (FN), and the 1/3 radius (1/3R). Pearson correlations related psoas CSA and bone imaging parameters before and after correcting for height and weight. Among 88 patients included, mean age was 63 ± 12 years, BMI was 28 ± 7 kg/m2, 47 (53 %) were female. Larger psoas CSA was associated with higher vBMD, greater Ct thickness and better Tb microarchitecture (higher Tb number and lower Tb separation) at the tibia and radius. Larger psoas CSA was also associated with greater aBMD at TH and FN bilaterally and 1/3R (r 0.33 to 0.61; p < 0.002 for all comparisons). Psoas CSA was not associated with aBMD at the LS. Similar results were observed when relating PMI, and adjusting for age, height and weight to HR-pQCT and DXA measurements. Investigation of subgroups by sex demonstrated that relationships were similar magnitude among women but not the men. Patients who underwent primary compared to revision spine surgery had similar associations. Our results demonstrate a link between psoas muscle size and peripheral bone microarchitecture among patients undergoing posterior lumbar spinal fusion. Given the importance of both muscle and skeletal integrity to the success of spine surgery, further study regarding the associations between measurements of psoas muscle, bone microarchitecture, and surgical outcomes is warranted.

Helical to wide volume acquisition in lumbar spine CT: Structures scoring based analysis

This study aims to compare the effectiveness of standard helical CT (HMCT) and volume CT (VMCT) protocols for lumbar spine imaging in terms of radiation dose and image quality. Two groups of 56 patients each (32 males, 24 females) who underwent lumbar spine CT were evaluated. The first group was imaged using HMCT and the second with VMCT. Dosimetric parameters including CTDIvol, DLP, and SSDE for both protocols were assesed and compared to evaluate radiation exposure. Image quality was assessed through quantitative analysis of Hounsfield Units (HU) and image noise, and qualitative analysis based on anatomical structure scoring by four reviewers. The VMCT protocol significantly reduced the mean CTDIvol (13 ± 3 mGy vs. 26 ± 6 mGy), DLP (270 ± 29 mGy cm vs. 609 ± 71 mGy cm), and effective dose (5 ± 0 mSv vs. 11 ± 1 mSv) compared to HMCT. SSDE was also lower for VMCT (15.6 ± 4.8 mGy) versus HMCT (31.8 ± 9.1 mGy). Despite this reduction in radiation dose, VMCT showed increased image noise across all anatomical regions, though differences in HU values were region-specific. Qualitative scoring revealed that VMCT images were similar in clarity and sharpness to HMCT images, with only marginally lower scores for most structures. VMCT significantly reduces radiation exposure compared to HMCT with observed difference in noise and CT number. The VMCT protocol can represent a promising tool in terms of radiation protection of patients while image quality needs further evaluation to take into consideration other parameters.

Feasibility of deep learning algorithm in diagnosing lumbar central canal stenosis using abdominal CT.

To develop a deep learning algorithm for diagnosing lumbar central canal stenosis (LCCS) using abdominal CT (ACT) and lumbar spine CT (LCT). This retrospective study involved 109 patients undergoing LCTs and ACTs between January 2014 and July 2021. The dural sac on CT images was manually segmented and classified as normal or stenosed (dural sac cross-sectional area ≥ 100 mm2 or < 100 mm2, respectively). A deep learning model based on U-Net architecture was developed to automatically segment the dural sac and classify the central canal stenosis. The classification performance of the model was compared on a testing set (990 images from 9 patients). The accuracy, sensitivity, and specificity of automatic segmentation were quantitatively evaluated by comparing its Dice similarity coefficient (DSC) and intraclass correlation coefficient (ICC) with those of manual segmentation. In total, 990 CT images from nine patients (mean age ± standard deviation, 77 ± 7years; six men) were evaluated. The algorithm achieved high segmentation performance with a DSC of 0.85 ± 0.10 and ICC of 0.82 (95% confidence interval [CI]: 0.80,0.85). The ICC between ACTs and LCTs on the deep learning algorithm was 0.89 (95%CI: 0.87,0.91). The accuracy of the algorithm in diagnosing LCCS with dichotomous classification was 84%(95%CI: 0.82,0.86). In dataset analysis, the accuracy of ACTs and LCTs was 85%(95%CI: 0.82,0.88) and 83%(95%CI: 0.79,0.86), respectively. The model showed better accuracy for ACT than LCT. The deep learning algorithm automatically diagnosed LCCS on LCTs and ACTs. ACT had a diagnostic performance for LCCS comparable to that of LCT.

The Effectiveness of Artificial Intelligence-based Pedicle Screw Trajectory Planning in Patients With Different Levels of Bone Mineral Density.

Retrospective cohort study. To evaluate the effectiveness of pedicle screw trajectory planning based on artificial intelligence (AI) software in patients with different levels of bone mineral density (BMD). AI-based pedicle screw trajectory planning has potential to improve pullout force (POF) of screws. However, there is currently no literature investigating the efficacy of AI-based pedicle screw trajectory planning in patients with different levels of BMD. The patients were divided into 5 groups (group A-E) according to their BMD. The AI software utilizes lumbar spine CT data to perform screw trajectory planning and simulate AO screw trajectories for bilateral L3-5 vertebral bodies. Both screw trajectories were subdivided into unicortical and bicortical modes. The AI software automatically calculating the POF and pullout risk of every screw trajectory. The POF and risk of screw pullout for AI-planned screw trajectories and AO standard trajectories were compared and analyzed. Forty-three patients were included. For the screw sizes, AI-planned screws were greater in diameter and length than those of AO screws (P<0.05). In groups B-E, the AI unicortical trajectories had a POF of over 200N higher than that of AO unicortical trajectories. POF was higher in all groups for the AI bicortical screw trajectories compared with the AO bicortical screw trajectories (P<0.05). AI unicortical trajectories in groups B-E had a lower risk of screw pullout compared with that of AO unicortical trajectories (P<0.05). AI unicortical screw trajectory planning for lumbar surgery in patients with BMD of 40-120mg/cm3 can significantly improve screw POF and reduce the risk of screw pullout.

Morphological and morphometric analysis of the Sacral Hiatus using lumbosacral spine CT scans: clinical relevance in Caudal Epidural Analgesia.

To conduct a morphological and morphometric analysis of the sacral hiatus (SH) using lumbosacral spine CT scans and to evaluate its clinical relevance in caudal epidural analgesia (CEA). This retrospective study analyzed 77 lumbosacral spine CT scans from a diverse patient population. The shape of the SH was classified into common types: inverted U, inverted V, irregular, and bilobed. Morphometric measurements included the length, width, and depth at the apex of the SH. The apex level of the SH was also determined in relation to the sacral vertebrae, and statistical analysis was performed to identify any correlation between the apex level and the morphometric dimensions. The most frequent SH shape was inverted U (68.83%), followed by inverted V (20.77%), irregular (9%), and a single instance of a bilobed shape (1.29%). The apex of the SH was most commonly located at the level of the S4 vertebra (75.32%), followed by the S3 vertebra (20.77%), S5 in two (2.59) and S2 in one (1.29%). No significant correlation was found between the level of the apex and the length, width, or depth of the SH. These findings indicate a high degree of anatomical variability in the SH, independent of the apex level. The anatomical variability of the SH, as observed in this study, underscores the need for individualized assessment during CEA. The lack of correlation between the apex level and the morphometric dimensions of the SH highlights the importance of imaging modalities such as ultrasound or fluoroscopy to ensure precise localization and effective analgesia administration. These insights can improve clinical outcomes by enhancing the accuracy and safety of caudal epidural procedures.

VerFormer: Vertebrae-Aware Transformer for Automatic Spine Segmentation from CT Images.

The accurate and efficient segmentation of the spine is important in the diagnosis and treatment of spine malfunctions and fractures. However, it is still challenging because of large inter-vertebra variations in shape and cross-image localization of the spine. In previous methods, convolutional neural networks (CNNs) have been widely applied as a vision backbone to tackle this task. However, these methods are challenged in utilizing the global contextual information across the whole image for accurate spine segmentation because of the inherent locality of the convolution operation. Compared with CNNs, the Vision Transformer (ViT) has been proposed as another vision backbone with a high capacity to capture global contextual information. However, when the ViT is employed for spine segmentation, it treats all input tokens equally, including vertebrae-related tokens and non-vertebrae-related tokens. Additionally, it lacks the capability to locate regions of interest, thus lowering the accuracy of spine segmentation. To address this limitation, we propose a novel Vertebrae-aware Vision Transformer (VerFormer) for automatic spine segmentation from CT images. Our VerFormer is designed by incorporating a novel Vertebrae-aware Global (VG) block into the ViT backbone. In the VG block, the vertebrae-related global contextual information is extracted by a Vertebrae-aware Global Query (VGQ) module. Then, this information is incorporated into query tokens to highlight vertebrae-related tokens in the multi-head self-attention module. Thus, this VG block can leverage global contextual information to effectively and efficiently locate spines across the whole input, thus improving the segmentation accuracy of VerFormer. Driven by this design, the VerFormer demonstrates a solid capacity to capture more discriminative dependencies and vertebrae-related context in automatic spine segmentation. The experimental results on two spine CT segmentation tasks demonstrate the effectiveness of our VG block and the superiority of our VerFormer in spine segmentation. Compared with other popular CNN- or ViT-based segmentation models, our VerFormer shows superior segmentation accuracy and generalization.

Digital anatomical features of morphological development in C2–C7 neurocentral synchondrosis in children aged 1–6 years: a retrospective study of CT images

BackgroundWith the continuous improvement of diagnosis and treatment technology for cervical spine-related diseases in children at home and abroad, the demand for exploring the developmental anatomy and function of children's cervical spine of different ages is increasing. So the aim of this study was to investigate the changes of anatomical indicators in neurocentral synchondrosis (NCS) of C2–C7 with age and the developmental characteristics of different vertebrae in children aged 1–6 years old.MethodA retrospective collection of 160 cases of normal cervical spine CT images of children aged 1–6 years old in provincial tertiary hospitals, according to the age group of 1-year-old into 6 groups. The original data of continuously scanned cervical spine tomography images were imported into Mimics16.0 software, under the two-dimensional image window, selected the measurement tool under the Measurements toolbar to measure and statistically analyzed the anatomical indicators such as cross diameter, sagittal diameter, height, perimeter and area of NCS in the C2–C7 segment of the cervical spine on the coronal plane and cross-section.ResultsThere was no significant difference in the anatomical indexes of cervical spine NCS in children compared with the left and right sides of the same vertebrae (P > 0.05). The same cervical spine generally had differences between the age groups of 1–4 years old and 5–6 years old (P < 0.05).The transverse diameter and circumference gradually decreased with age; the sagittal diameter and height showed a slight increase trend; there was a maximum area at 2 years of age. In different cervical vertebrae of the same age group, the NCS values of C3, C4, and C5 varied greatly, which showed that the ossification process of cervical cartilage was faster than that at the upper and lower ends. There were obvious differences between C2 and the rest of the cervical vertebral segments’ NCS ossification process. C7 was also very different from the rest of the cervical vertebrae segments, presumably more similar to the thoracic spine.ConclusionsThe anatomical indexes of C2–C7 NCS in children have obvious developmental regularities at different ages, and there are also regularities between cervical segments.

The reduced cortical bone density in vertebral bodies: risk for osteoporotic fractures? Insights from CT analysis

BackgroundThere is a corresponding increase in the prevalence of osteoporosis and related fractures with the aging population on the rise. Furthermore, osteoporotic vertebral compression fractures (OVCF) may contribute to higher patient mortality rates. It is essential to conduct research on risk factors for OVCF and provide a theoretical basis for preventing such fractures.MethodsWe retrospectively recruited patients who had spine CT for OVCF or back pain. Demographic and CT data were collected. Quantitative computed tomography (QCT) software analyzed the CT data, using subcutaneous fat and paraspinal muscles as reference standards for BMD processing. BMD of cortical and cancellous bones in each patient’s vertebral body was determined.ResultsIn this study, 144 patients were divided into non-OVCF (96) and OVCF (48) groups. Non-OVCF patients had higher cortical BMD of 382.5 ± 52.4 to 444.6 ± 70.1 mg/cm3, with T12 having the lowest BMD (p < 0.001, T12 vs. L2). Cancellous BMD ranged from 128.5 ± 58.4 to 140.9 ± 58.9 mg/cm3, with L3 having the lowest BMD. OVCF patients had lower cortical BMD of 365.0 ± 78.9 to 429.3 ± 156.7 mg/cm3, with a further decrease in T12 BMD. Cancellous BMD ranged from 71.68 ± 52.07 to 123.9 ± 126.2 mg/cm3, with L3 still having the lowest BMD. Fractured vertebrae in OVCF patients (T12, L1, and L2) had lower cortical bone density compared to their corresponding vertebrae without fractures (p < 0.05).ConclusionsT12 had the lowest cortical BMD and L3 had the lowest cancellous BMD in OVCF patients, with T12 also having the highest incidence of osteoporotic fractures. These findings suggest that reduction in cortical BMD has a greater impact on OVCF than reduction in cancellous BMD, along with biomechanical factors.

Is older age an appropriate criterion alone for ordering cervical spine CT after trauma.

Is older age an appropriate criterion alone for ordering cervical spine CT after trauma.

Nonquantitative CT scan Hounsfield unit as a determinant of cervical spine bone density.

Hounsfield unit (HU) values measured using CT have been increasingly recognized to stand as a reliable corollary to dual-energy x-ray absorptiometry (DEXA) scores in evaluating bone mineral density. The authors examined the correlation between cervical HU values and DEXA T- and Z-scores and determined novel cervical HU thresholds for determining bone quality classification. One hundred patients who underwent both cervical spine CT and DEXA, 85 patients who underwent both lumbar CT and DEXA, and 128 patients who underwent cervical and lumbar CT within 24 months at a single institution were included in this retrospective review. Two independent reviewers collected HU values from 3 cervical vertebral levels (C4-6) and 4 lumbar vertebral levels (L1-4), and the averaged values were used. Pearson's correlation coefficient analysis was performed to compare the association of cervical HU values with lumbar HU values and T- and Z-scores. The mean cervical HU values for each DEXA classification were calculated and compared. Receiver operating characteristic (ROC) curves were created to determine the threshold and its sensitivity and specificity for diagnosis. Cervical (C4-6) HU values and average, lumbar, and femoral T- and Z-scores had significant correlations (0.436 > r > 0.274, all p < 0.01). A strong positive correlation between cervical and lumbar HU values was found (r = 0.79, p < 0.01). The average cervical HU value of healthy patients was 361.2 (95% CI 337.1-385.3); of osteopenic patients, 312.1 (95% CI 290.3-333.8); and of osteoporotic patients, 288.4 (95% CI 262.6-314.3). There was a significant difference between the cervical HU values of healthy and osteopenic patients (p = 0.0134) and between those of healthy and osteoporotic patients (p = 0.0304). The cervical HU value of 340.98 was 73.5% specific and 57.9% sensitive for diagnosing osteopenia with an area under the ROC (AUROC) curve of 0.655. The cervical HU value of 326.5 was 88.9% specific and 63.2% sensitive for diagnosing osteoporosis with an AUROC curve of 0.749. This is the second large-scale study and first with a patient population from the United States to show that HU values obtained using cervical CT were significantly correlated with bone quality based on DEXA T- and Z-scores and to establish a cervical HU threshold for determining bone quality classification. These results show that cervical HU values can and should be used to predict poor bone quality in surgical cervical spine patients.

Early effects of unilateral biportal endoscopic posterior total laminectomy decompression in the treatment of cervical stenosis

To investigate the early efficacy and safety of unilateral biportal endoscopic posterior total laminectomy decompression in the treatment of cervical stenosis (CS). The clinical data of 28 patients with CS treated by unilateral biportal endoscopic posterior total laminectomy decompression from January 2021 to October 2022 in the Henan NO.3 Provincial People's Hospital were retrospectively analyzed. Of the patients, 16 were male and 12 were female, the mean age was (55.6±9.6) years. The CS occurred at C3-4 level in 1 cases, at C4-5 level in 3 cases, at C5-6 level in 16 cases and at C6-7 level in 8 cases. Each case was compared at the moment of pre-operation and final follow-up by the Japanese Orthopedic Association (JOA) score. The postoperative complications were recorded. The JOA improvement rate was computed at the final follow-up. As a result, all patients underwent successful surgery and were followed up for (11.6±4.7) months. The operation time was (43.0±5.3) min. Intraoperative blood loss (7.9±2.8) ml; Postoperative drainage volume (8.1±2.3) ml. The JOA score increased from 7.9±1.2 before surgery to 13.5±1.3 six months after surgery, and it was 13.7±1.2 at the last follow-up, the differences between postoperative and preoperative were both statistically significant (both P<0.001). No complications occurred, such as cerebrospinal fluid leakage, nerve injury and intraspinal hematoma. At the last follow-up, cervical spine X-ray or CT evaluation showed no instability in the operative segment. The overall curative effect was evaluated according to JOA score at the last follow-up: 16 cases got excellent outcome, 7 cases got good and 2 cases got medium outcome, with an excellent and good rate of 89.3% (25/28). This study shows that unilateral biportal endoscopic posterior total laminectomy decompression in the treatment of single-level cervical stenosis can achieve satisfactory efficacy, has no impact on spinal stability, and has a high safety.

Automatic 3D reconstruction of vertebrae from orthogonal bi-planar radiographs

When conducting spine-related diagnosis and surgery, the three-dimensional (3D) upright posture of the spine under natural weight bearing is of significant clinical value for physicians to analyze the force on the spine. However, existing medical imaging technologies cannot meet current requirements of medical service. On the one hand, the mainstream 3D volumetric imaging modalities (e.g. CT and MRI) require patients to lie down during the imaging process. On the other hand, the imaging modalities conducted in an upright posture (e.g. radiograph) can only realize 2D projections, which lose the valid information of spinal anatomy and curvature. Developments of deep learning-based 3D reconstruction methods bring potential to overcome the limitations of the existing medical imaging technologies. To deal with the limitations of current medical imaging technologies as is described above, in this paper, we propose a novel deep learning framework, ReVerteR, which can realize automatic 3D Reconstruction of Vertebrae from orthogonal bi-planar Radiographs. With the utilization of self-attention mechanism and specially designed loss function combining Dice, Hausdorff, Focal, and MSE, ReVerteR can alleviate the sample-imbalance problem during the reconstruction process and realize the fusion of the centroid annotation and the focused vertebra. Furthermore, aiming at automatic and customized 3D spinal reconstruction in real-world scenarios, we extend ReVerteR to a clinical deployment-oriented framework, and develop an interactive interface with all functions in the framework integrated so as to enhance human–computer interaction during clinical decision-making. Extensive experiments and visualization conducted on our constructed datasets based on two benchmark datasets of spinal CT, VerSe 2019 and VerSe 2020, demonstrate the effectiveness of our proposed ReVerteR. In this paper, we propose an automatic 3D reconstruction method of vertebrae based on orthogonal bi-planar radiographs. With the 3D upright posture of the spine under natural weight bearing effectively constructed, our proposed method is expected to better support doctors make clinical decision during spine-related diagnosis and surgery.

Does ponticulus posticus affect vertebral artery diameter.

Ponticulus Posticus, atlantooccipital ligament ossification-induced anomaly, surrounds the vertebral artery and the first cervical nerve root. It is believed to wrap around the first cervical nerve root and the vertebral artery, causing compression. We hypothesized that it would also reduce the diameter of the vertebral artery. Between January 1, 2022, and December 31, 2022, cervical spine CT scans taken for any reason were retrospectively reviewed. The images of 1365 patients suitable for evaluation were evaluated by two expert radiologists in 3 dimensions. Among patients with PP, those who underwent cervical angiography were identified for vertebral artery diameter measurement. The average age of the 1365 individuals included in the study (732 males, 633 females) was 55.78 (± 18.85) with an age range of 1-96. Among this group, PP was detected in 288 individuals, resulting in a total prevalence of 21.1%. Right and left vertebral artery diameters were significantly lower in patients with complete PP compared to the absent group (p < 0,001, p < 0,001, respectively). Additionally, it was observed that width and height diameters and artery diameters were positively correlated in patients with Complete PP. Ponticulus posticus can cause vertebrobasilar insufficiency by reducing the diameter of the vertebral artery. Therefore, imaging and detailed evaluation of this region are important in symptomatic patients.

X-CTCANet: 3D spinal CT reconstruction directly from 2D X-ray images

X-CTCANet: 3D spinal CT reconstruction directly from 2D X-ray images

Microsurgical and Descriptive Three-Dimensional Analysis of the Subarticular Trigone: A Guidemap for Standardizing Lateral Recess Decompression.

Background Lateral recess decompression has remained a cornerstone spinal procedure for decades. Despite its popularity, a significant lack of evidence in the literature exists concerning microsurgical anatomy and pertinent surgical landmarks, resulting in non-standardized nomenclature, descriptions, and surgical approaches. Objective This study provides an in-depth microsurgical and descriptive analysis of the subarticular trigone (SAT), serving as an anatomical guide and a tool to foster consistency in nomenclature and standardization of surgical approaches. Methods We analyzed 35 high-resolution lumbar spine CT scans, employing three-dimensional (3D) processing techniques. The SAT is introduced to delineate the bony prominence enveloping the superiomedial quadrant of the pedicle. The SAT encompasses two zones: (1) a superior zone above the superior pedicular line, corresponding to the medial part of the body of the ascending facet (AF), and (2) an inferior zone between the superior and middle pedicular lines, corresponding to the root of the AF and the medial pars/superior lamina. The superior subarticular point (SSP) and medial subarticular point (MESP) serve as key reference landmarks. The SAT forms the roof of the lateral recess and the region requiring resection during decompression of the traversing root in this anatomical corridor. Various measurements, including SSP and MESP to lateral pars, tip of the facet and spino-laminar junction distance, mean width of the sublaminar ridge (SLR), and percentage of the facet that requires resection for adequate SAT decompression, were carried out. Results The mean distance of the SSP to the lateral pars ranges from 7 to 9.2 mm, to the tip of the descending from 9.3 to 10.1 mm, and to the spino-laminar junction from 6.7 to 8.1 mm. The MESP is located at a mean distance of 5.4-6.9 mm from the medial pedicular line. The mean width of the SLR varies from 18.6 to 29.4 mm. Finally, the percentage of total facet width that needs to be removed to adequately decompress the SAT extends from 32% at L4 to 36% at L1. Conclusions This study presents comprehensive insights into the surgical, descriptive, and correlative anatomy of the lateral recess, emphasizing the SAT. The extrapolated data offer a framework for achieving uniformity in surgical planning and advocate for standardized nomenclature.