Three-dimensional Computed Tomography Reconstruction Research Articles

A novel method for determining the X-ray beam angulation of the supraspinatus outlet view.

Rapid and accurate quantification of the supraspinatus outlet view (SOV) is a clinical challenge. To quantify the X-ray beam angle of the SOV using the horizontal angle of the subscapular spine line (SSSL) and to further verify the feasibility of this method. A total of 119 patients who underwent shoulder computed tomography (CT) examination were enrolled in the retrospective study. Three-dimensional (3D) CT reconstruction was performed and manually adjusted to provide the position similar to SOV. The rotation angle of the 3D image along the long axis of the human body (marked as β) was obtained. The horizontal angle of SSSL (marked as α) was measured on the anteroposterior localizer image of shoulder CT. Pearson correlation and linear regression correlation analysis were performed. In addition, the first-time success rate between the experience-based group and the measurement-based group were compared to verify the novel method. We found a linear correlation between α and β (r = 0.962; P = 0.000). There was no significant correlation between the experience-based group and the measurement-based group in terms of age (P = 0.500), sex (P = 0.397), and side (P = 0.710), but there was a significant statistical difference in the first success rate between the two validation groups (χ2 = 5.808a, P = 0.016). This novel quantitative measurement method for determining the X-ray beam angle of SOV using the horizontal angle of SSSL is feasible.

The left common iliac vein area

OBJECTIVE: To analyze the normal reference left common iliac vein (LCIV) area in chronic venous disease (CVD) patients with or without May–Thurner syndrome (MTS) and its relevant influencing factors. MATERIALS AND METHODS: A prospective analysis of patients with left lower extremity CVD was conducted in a single institution from January to August 2019. A total of 326 patients, 98 with MTS and 228 without MTS after computed tomography (CT) venography, were finally enrolled in this study, and their basic information was recorded. MTS cases were distinguished from non-MTS cases by calculating area stenosis rate with CT three-dimensional reconstruction. The reference area of LCIV was also defined and calculated to analyze its coefficient of variation and relationship with influencing factors in patients with and without MTS. RESULTS: Ninety-eight cases of MTS and 228 cases of non-MTS were finally analyzed. In the MTS group, the mean area of reference LCIV was significantly lower (116.29 ± 53.17 mm2 vs. 160.44 ± 52.99 mm2, P < 0.01) and showed greater variability (0.21 ± 0.13 vs. 0.16 ± 0.08, P = 0.04) compared with non-MTS group. Obesity radio was significantly higher in non-MTS group (28.5% vs. 16.3%, P = 0.03). In both MTS and non-MTS groups, the increase of body mass index (BMI) was generally associated with statistically significant increases in the LCIV area (P = 0.002 and P = 0.005), while other factors showed no statistically significant correlation. CONCLUSIONS: The reference area of LCIV was redefined in this study. We found that the increase of the LCIV area in both MTS and non-MTS groups was correlated with an increase in BMI. Furthermore, a smaller area of reference LCIV and more variability in the LCIV area were found in the MTS group in contrast to the non-MTS group.

Internal Jugular to Atrial Bypass with Spiral Vein Graft for Superior Vena Cava Syndrome

The patient was a 41-year-old woman with a history of postpartum class New York Heart Association class II cardiomyopathy. She had undergone biventricular implanTable cardiac defibrillator lead extraction. The procedure was complicated by laceration of the superior vena cava, innominate artery, and confluence of the left subclavian artery. Emergent repair with full cardiopulmonary bypass with bovine pericardial patch angioplasty was performed. During the course of 2 years, the patient had developed superior vena cava syndrome. She described worsening symptoms of severe headaches, blurred vision, near syncope with bending over, and a choking sensation despite sleeping at a 45° head-up angle. Additionally, the patient had developed moderate tricuspid valve regurgitation, which required repair. We elected to repair this patient with a spiral vein graft, in addition to tricuspid valve annuloplasty. Bilateral great saphenous veins were harvested and wrapped around a 36F chest tube such that a 9-mm × 12-cm spiral vein graft was created (Fig 1). After repair of the tricuspid valve, the right internal jugular vein was exposed, and the graft was tunneled through the thoracic inlet and inside a 12-mm ringed polytetrafluoroethylene graft to provide external support. The graft was then anastomosed from the right internal jugular vein to the right atrium. The patient did well and was discharged 6 days postoperatively. During follow-up, the patient has done very well (Fig 2). Five months after surgery, a venogram demonstrated a patent graft, with no pressure gradient across the graft.Fig 2Preoperative (Left) and postoperative (Right) three-dimensional computed tomography reconstructions of the patient demonstrating remarkably decreased venous collaterals. (Bottom) A postoperative venogram demonstrating the widely patent jugular–atrial venous bypass.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A New Algorithm for Classifying Acetabular Fracture Patterns on Three-dimensional Computed Tomography Reconstructions Markedly Improves Residents' Ability to Correctly Classify Fractures.

CT and three-dimensional (3D) CT reconstructions have been shown to improve the understanding of acetabular fractures. With the increased availability of 3D pelvic CT reconstructions, our goal for this study was to develop an algorithm to aid residents in the classification of acetabular fractures. We hypothesized that the use of a stepwise algorithm will markedly enhance the trainees' ability to correctly identify acetabular fracture patterns. This was a multicenter study that included 33 residents. Residents reviewed 15 sets of 3D reconstructions of the 10 acetabular fracture patterns. Residents completed the first round, and the results were collected electronically. Three weeks later, they were asked to classify the fractures a second time with the use of the algorithm. The number of correct responses from the two sessions was analyzed to determine if the algorithm improved residents' ability to correctly classify fracture patterns. Thirty-three residents classified 15 fractures which yielded 495 unique responses. Residents correctly classified 52.5% (260/495) of fractures without the algorithm, which significantly increased to 77.5% (384/495) (P = 0.001) with the algorithm. When stratified by year in residency, all residents were able to correctly classify markedly more fractures with the algorithm. Overall, we believe this method is a reproducible diagnostic tool that will assist residents in classifying acetabular fractures. We were able to demonstrate that with the use of this algorithm, residents' ability to correctly classify acetabular fractures is markedly enhanced, regardless of year in training. This algorithm will be a useful adjunct to assist and advance trainees' education and understanding of a complex topic.

A Prospective Study to Examine the Association of the Foramen Ovale Size with Intraluminal Pressure of Pear-Shaped Balloon in Percutaneous Balloon Compression for Trigeminal Neuralgia.

IntroductionPercutaneous balloon compression (PBC) is an effective and safe option for patients with trigeminal neuralgia. A pear-shaped balloon can be used to identify the proper compression of the Gasserian ganglion during the PBC procedure. The aim of this study was to evaluate the relationship between the foramen ovale (FO) size and intraluminal pressure of the pear-shaped balloon.MethodsThirteen patients that presented with classical trigeminal neuralgia were scheduled to undertake PBC surgery at the Pain Department of the Third Xiangya Hospital, Central South University, from November 2020 to April 2021. Three-dimensional computed tomography reconstruction of the skull base was performed to capture the feature of FO preoperatively. The intraluminal pressure was continuously recorded when a pear-shaped balloon was obtained during the procedure. Correlation analysis was calculated to determine the association of the intraluminal balloon pressure with FO parameter.ResultsAll participants reported complete relief of pain at discharge. The enduring analgesic effect of PBC was maintained in all patients with a median follow-up up to 5.5 months (range, 3–8 months). The average intraluminal balloon pressure was 161.5 ± 29.4 kPa at the initial compression (P1), and 134.8 ± 21.5 kPa at the ending of compression (P2), respectively. P1 was significantly correlated with the length (r = 0.61, P = 0.024) of FO. Similarly, a significant and positive correlation was observed between P2 and the length (r = 0.63, P = 0.022) of FO.ConclusionsPreoperative assessment of FO may be a potential predictor of intraluminal pressure to reach a pear-shaped balloon during PBC treatment. Narrow FO is associated lower intraluminal balloon pressure.

Efficacy and Safety of Awake Computed Tomography-Guided Percutaneous Balloon Compression of Trigeminal Ganglion for Trigeminal Neuralgia.

To describe the method and clinical efficacy of awake computed tomography (CT)-guided percutaneous balloon compression (PBC) as a treatment for trigeminal neuralgia (TN). In this case series, patients with TN were treated with awake CT-guided PBC and followed up for treatment efficacy and complications for 12 months. A single-center study. A total of 66 patients with medical treatment-refractory TN were recruited for the study. The procedure was performed under moderate sedation. A balloon catheter was inserted through a trocar needle to reach Meckel's cavity under CT guidance. The position and optimal shape of the contrast-filled balloon were confirmed with CT three-dimensional reconstruction. Compression of the trigeminal ganglion was considered complete when the patient notified operators about facial hypoesthesia or the resolution of TN symptoms. All patients were followed up monthly for 12 months to monitor treatment efficacy and complications. The average trigeminal ganglion compression time was 272 ± 81 seconds, at which point the patients reported significant facial hypoesthesia compared with the contralateral side or resolution of triggered pain in the affected area. All patients had resolution of TN symptoms for 6 months, with a 1-year recurrence rate of 13%. The overall safety profile was improved with the technique described in this study. Side effects, such as hypoesthesia and mastication weakness, were overall mild and did not impact patients' quality of life. Some complications that historically have been associated with PBC, such as diplopia and keratitis, were not present. This new awake CT-guided PBC technique produces better outcomes than the traditional PBC under fluoroscopy guidance and general anesthesia.

Value of PET/CT Combined with CT Three-dimensional Reconstruction in Distinguishing Different Pathological Subtypes of Early Lung Adenocarcinoma

背景与目的早期肺腺癌中病理亚型以贴壁为主型的浸润性腺癌（lepidic predominant invasive adenocarcinoma, LPA）与原位腺癌（adenocarcinoma in situ, AIS）、微浸润性腺癌（microinvasive adenocarcinoma, MIA）的良好预后相似，临床上也迫切需要能够区分LPA与非LPA型浸润性腺癌（non-lepidic predominant invasive adenocarcinoma, non-LPA）的手段，本研究拟通过正电子发射型计算机断层显像（positron emission computed tomography, PET）/计算机断层扫描（computed tomography, CT）的最大标准化摄取值（maximal standard uptake value, SUVmax）和CT三维重建后参数探讨术前影像学表现为部分实性结节（part-solid nodules, PSNs）的早期肺腺癌不同病理亚型间的关系。方法回顾性分析2016年1月-2019年1月于江苏省苏北人民医院胸外科行解剖性肺切除术且影像学表现为PSNs的早期肺腺癌患者资料，所有患者胸部增强CT和PET/CT资料完整可获取，利用Mimics软件行三维重建，获取肿瘤体积、肿瘤三维平均CT值（3-dimensional mean-CT value, 3Dm-CT）、SUVmax等数据，采用SPSS 25.0进行统计分析，GraphPad Prism 8.3.0绘制受试者工作曲线（receiver operating curve, ROC），P < 0.05为差异有统计学意义。结果最终共计67例患者纳入本研究，按病理亚型不同将所有患者分为两组，AIS、MIA及浸润性腺癌（invasive adenocarcinoma, IAC）中的LPA归为低危组28例（41.8%），其余non-LPA如腺泡型（acinar pattern-predominant adeno-carcinoma, APA）、乳头型（papillary pattern-predominant adenocarcinoma, PPA）、微乳头型（micropapillary pattern-predominant adeno-carcinoma, MPA）归为高危组39例（58.2%），两组间SUVmax（t=3.153, P=0.002）、肿瘤体积（t=3.331, P=0.001)、实性/磨玻璃成分体积（t=2.74, P=0.006) /（t=3.127, P=0.002）、实性/磨玻璃成分3Dm-CT（t=3.655, P < 0.001) /（t=7.082, P < 0.001) 均具有显著统计学意义。ROC曲线提示：SUVmax[曲线下面积（area under curve, AUC）=0.727]、肿瘤体积（AUC=0.740）、磨玻璃成分体积（AUC=0.725）、实性成分3Dm-CT（AUC=0.763）、磨玻璃成分3Dm-CT（AUC=0.756）预测效能最佳。将上述AUC > 0.7的协变量纳入多因素ROC曲线分析，获得联合预测因子（AUC=0.835）具有中等以上预测价值。结论PET/CT中SUVmax和CT三维重建参数与影像学表现为PSNs的早期肺腺癌的不同病理亚型具有显著相关性，联合SUVmax、肿瘤体积、磨玻璃成分体积和实性/磨玻璃成分3Dm-CT对鉴别表现为PSNs的早期肺腺癌的病理亚型具有一定价值。

Use of Three-Dimensional Computed Tomography Reconstruction and RealTime Ultrasound-Guided Spinal Anaesthesia in a Patient with Ankylosing Spondylitis: A Case Report

Use of Three-Dimensional Computed Tomography Reconstruction and RealTime Ultrasound-Guided Spinal Anaesthesia in a Patient with Ankylosing Spondylitis: A Case Report

Three-Dimensional Computed Tomography Reconstruction and Measurement of Nasal End Deformity in Complete Unilateral Cleft Lip and Palate.

The repair of nasal deformities secondary to cleft lip and palate is complex and requires reliable preoperative nasal 3-dimensional assessment. This study explored nasal end (defined as the lower third of the external nasal and vestibular parts of the nasal cavity) deformities secondary to unilateral complete cleft lip and palate. Three-dimensional nasal end morphometric measurements were obtained from 48 patients who had undergone Millard cleft lip repair and reached skeletal maturity (cleft group) and from 36 age- and ethnicity-matched normal subjects (control group). For the cleft group, paired t tests and 1-way analysis of covariance were used to evaluate the internal and external morphological characteristics of the cleft and noncleft sides of the nasal end, and correlation analysis was done to evaluate the relationship between cleft-side measurements. In the cleft group, the cleft side showed significantly smaller nasal vestibular volume and skin area, nostril area, nasal column length, and nostril height and greater nostril base length and nasal alar length than the noncleft side (all P < 0.05). Controlling for sex, there were significant differences in the nasal vestibular volume and skin area, internal nasal valve area, long nostril diameter, nostril base length, columella length, nostril height, and nasal alar length between the cleft and control groups (all P < 0.05). On the cleft side, the area of the skin lining of the nasal vestibule positively correlated with the alar length (r = 0.67, P < 0.05). Three-dimensional nasal end reconstruction provides a more detailed preoperative nasal end morphological evaluation than previously available techniques. Level III, case-control study.

Simulation of coal microstructure characteristics under temperature-pressure coupling based on micro-computer tomography

The distribution of pore-fracture structure in coal directly affects the storage and migration characteristics of fluids. Simultaneously, under the condition of high buried depth, the coal structure is further changed by the temperature-pressure coupling. To study the pore size distribution of coal and the deformation characteristics of different pore-fracture structures under temperature-pressure coupling conditions, six different coal structure models are constructed using three-dimensional computer tomography reconstruction in this work. The box-counting algorithm is used to calculate the fractal dimensions of the pore-fracture structure and pore clusters in different pore sizes of coal. In the meantime, the fractal characteristics of the pore structure in different pore sizes are analyzed. Based on the coal structure model, a linear elastic deformation model under the temperature-pressure coupling is constructed. Moreover, the relationship of porosity and fractal dimension with the deformation of models is studied. The research results show that the porosity positively correlated with fractal dimension. The changes of pore volume fraction and fractal dimension in each pore size distribution range are consistent. Under the temperature-pressure coupling condition, both the model porosity and fractal dimension exhibit a quadratic function relationship with deformation. The deformation analysis of the three-dimensional models and two-dimensional cross-sections show that as the porosity and fractal dimension increase, the coal body deformation exhibits a trend of first decreasing and subsequent increasing. Low fractal dimension and high porosity could increase the model deformation. The research results can afford a theoretical basis for the study of coal structure characteristics under complex conditions.

Morphometric analysis and three-dimensional computed tomography reconstruction of the long bones of femoral and crural regions in Van cats.

This study was conducted to determine the morphometric features and to make the three-dimensional (3D) reconstruction of the images obtained by computed tomography (CT) of the main long bones (femur, tibia, fibula) in Van cats, and to reveal the biometric differences between these measurement values of both sexual dimorphism and homotypic variations. A total of 16 adult Van cats, 8 male and 8 female, were used in the study. The pelvic limb long bones of the cats, which were anesthetized with the ketamine-xylazine combination, were scanned with a CT device and their images were obtained. These images were converted to a 3D structure by means of MIMICS 20.1 (The Materialise Group, Leuven, Belgium) software programme. Then, morphometric, volumetric, surface arae measurements of these bones were calculated and statistical analyses were performed. In the analysis, it was observed that right greatest length (GL), left GL, right greatest length from caput ossis femoris (GLc), left greatest breadth of the distal end (Bd), right volume (V), and left V measurement values of the femur; left GL1, right greatest breadth of the proximal end (Bp), right Bd, left Bd, right smallest breadth of the diaphysis (SD), right V, left V, and right surface area (SA) measurement values of the tibia; right V, left V, right SA, and left SA measurement values of the fibula were statistically significantly higher in male cats than in female cats (p < 0.05). The volume and surface area measurement values of the femur, tibia and fibula of male and female cats were determined as 8.57 ± 1.33 cm3 and 7.00 ± 0.49 cm3, 64.28 ± 6.72 cm2 and 59.42 ± 4.72 cm2; 7.56 ± 1.28 cm3 and 6.15 ± 0.52 cm3, 56.89 ± 6.47 cm2 and 52.72 ± 3.15 cm2; 1.10 ± 0.17 cm3 and 0.83 ± 0.05 cm3, 14.18 ± 1.61 cm2 and 11.95 ± 0.48 cm2, respectively. The statistical differences between the sexes in terms of the measurement parameters of the femur, tibia and fibula in adult Van cats were determined. We believe that these differences can be used in determining morphological variations of Van cats. In addition, it is thought that the data obtained from the present study would be beneficial to veterinary physicians in the clinical application areas in order to evaluate the pathological conditions related to these bones and to the studies in the field of zooarchaeology.

Anatomy and Correlation of the Coracoid Process and Coracoclavicular Ligament Based on Three-Dimensional Computed Tomography Reconstruction and Magnetic Resonance Imaging.

BackgroundThe anatomy of the coracoid process and coracoclavicular (CC) ligament have been described and the correlation between them has been assessed based on 3-dimensional computed tomography (CT) reconstruction and magnetic resonance imaging (MRI), which provide a guide for coracoclavicular ligament reconstruction.Material/MethodsData were collected from 300 patients who underwent both CT and MRI of the shoulder joint from January 2017 to January 2019 at the Jiang’an Hospital of Traditional Chinese Medicine. The coracoid process was observed and classified and parameters of the CC ligament were measured according to different corneal types. All of the statistics were collected and classified by 2 radiologists, and average values were determined.Measurements of segments were taken as follows: ab – In the coronal plane, the length of the CC ligament from the central point of the CC ligament at the clavicular attachment to the CC ligament at the center of the CC attachment); ac – The distance from the center point of the CC ligament at the supraclavicular attachment to the acromioclavicular joint; de – In the sagittal plane, the length of the CC ligament from the center of the clavicular attachment to the coracoid attachment point; fg – The maximum diameter of the CC ligament at the anterior and posterior margins of the clavicle attachment; hi – The largest diameter of the CC ligament at the anterior and posterior edge of the coracoid process attachment; dj – The distance of the coracoclavicular ligament from the center point of the coracoid process attachment to the coracoid process tip; kl – The distance in the supraclavicular plane from the coracoclavicular ligament to the subcoracoid process.ResultsThe analysis showed that there are 5 types of coracoid process: gourd (31%), short rod (20%), long rod (22.3%), wedge (10.3%), and water drop (6.3%). There were statistically significant differences between the lengths of the ac and hi segments in the among the wedge and gourd-type and the short rod and water drop-type coracoid processes. There were statistically significant differences between the lengths of the ab, de, and fg segments in the short rod, gourd, and long rod-type coracoid processes. There were statistically significant differences between the lengths of the ac, fg, hi, dj, and kl segments in the water drop, gourd, and long rod-type coracoid processes.ConclusionsThe present study indicated that measurement of the CC ligament and the different shapes of the coracoid process provide an anatomical basis for the diagnosis and treatment of shoulder diseases and the data can be used to improve the safety of CC ligament reconstruction.

Morphologic analysis of Chinese lumbar endplate by three-dimensional computed tomography reconstructions for helping design lumbar disc prosthesis.

Lumbar disc prostheses have been used increasingly in recent years. The successful design of lumbar disc prostheses depends on accurate morphometric parameters. However, the morphologic dimensions of lumbar endplate area have not been investigated in Chinese population.A total of 1800 lumbar endplates were retrospectively accessed in 150 Chinese adults. Eighteen parameters of each lumbar segment were measured by three-dimensional computed tomography reconstructions from T12/L1 to L5/S1. These obtained parameters were compared between genders, bilateral sides, vertebral segments, and different populations.Endplate length and width increased in general, and there was a significant decrease for length/width ratio from T12 to S1 (P = .03). The average concavity depth of the lower lumbar endplate (2.09 ± 0.93 mm) was usually larger than that of the upper lumbar endplate (1.61 ± 0.74 mm) (P = .02). The percentage of the most concave point of the upper and lower lumbar endplate was 50.01 ± 10.76% and 56.41 ± 9.93%, respectively. Anterior, medium, or posterior intervertebral endplate height was severally 10.01 ± 1.98 mm, 10.46 ± 2.03 mm, and 6.41 ± 1.74 mm, and increased among vertebral segments (P = .01).The intervertebral endplate angle significantly increased from T12-L1 to L5-S1 (P = .01). Parameters displayed significant difference between genders. The morphometric parameters of different populations also showed differences.In conclusion, there is a morphologic discrepancy in dimensions of lumbar endplate regarding genders, vertebral segments, and different populations. It is essential to design the lumbar disc prosthesis suited for Chinese patients specially, for which the morphometric parameters in our study can be utilized.

Morphometric Analysis and Three-Dimensional Computed Tomography Reconstruction of Thai Distal Femur

This study evaluates the distal femur morphology of the Thai population using a three-dimensional (3D) measurement method, measuring the distance between the triangular point of the femoral 3D model. The 3D model of 360 Thai femoral obtained from 180 volunteers (90 males, 90 females; range 20–50 years, average 32.8 years) was created using reverse engineering techniques from computed tomography imaging data. Using the 3D identified landmark method, the morphometric parameters evaluated included transepicondylar axis length (TEA), mediolateral length (ML), anteroposterior width (AP), medial anteroposterior width (MAP), lateral anteroposterior width (LAP), medial condyle width (MCW), lateral condyle width (LCW), intercondylar notch width (WIN), intercondylar notch depth (DIN), medial posterior condyle height (MPC), lateral posterior condyle height (LPC), femoral aspect ratio (ML/AP), lateral femoral aspect ratio (ML/LAP), and medial femoral aspect ratio (ML/MAP). The measured data were summarized for the analysis of an average value and standard deviation. Statistical analysis was performed using the independent samples t-test, unequal variances t-test, and linear regression. A p-value less than 0.05 (&lt;0.05) was regarded as statistically significant and indicates strong evidence of the hypothesis. Additionally, the K-means clustering analysis of Thai distal femoral to the optimum size of the prosthesis with the correlation between ML length and AP width was performed. The results found that the morphometric parameters of the Thai male distal femur were significantly different and higher than those of Thai females, except for the ratio of ML/AP and ML/MAP. Comparatively, there was a significant difference between the specific size of Thai distal femur and that of the Korean population, which was also smaller than that for Caucasians. In addition, there was a mismatch between the distal femoral component sizing of knee prosthesis and what is available and commonly used in Thailand. At least six sizes of ML and/or AP should be recommended for the reasonable design of distal femoral prosthesis for covering the anatomy of Thais. These data are useful for predicting the morphometric parameters in forensic anthropology and provide basic data for the design of knee prostheses suitable for the Thai population.

3D CT evaluation of femoral and tibial tunnels in anatomic double bundle anterior cruciate ligament reconstruction

BackgroundAn anatomical double bundle ACL reconstruction replicates the anatomy of native ACL as the tunnels are made to simulate the anatomy of ACL with AM and PL bundle foot prints. The goal of anatomic ACL reconstruction is to tailor the procedure to each patient’s anatomic, biomechanical and functional demands to provide the best possible outcome. The shift from single bundle to double bundle technique and also from transtibial to transportal method has been to provide near anatomic tunnel positions. PurposeTo determine the position of femoral and tibial tunnels prepared by double bundle ACL reconstruction using three dimensional Computed tomography. Study designA prospective case series involving forty patients with ACL tear who underwent transportal double bundle ACL reconstruction. MethodComputed tomography scans were performed on forty knees that had undergone double bundle anterior cruciate ligament reconstruction. Three-dimensional computed tomography reconstruction models of the knee joint were prepared and aligned into an anatomical coordinate axis system for femur and tibia respectively. Tibial tunnel centres were measured in the anterior-to-posterior and medial-to-lateral directions on the top view of tibial plateau and femoral tunnel centres were measured in posterior to anterior and proximal-to-distal directions with anatomic coordinate axis method. These measurements were compared with published reference data. ResultsAnalysing the Femoral tunnel, the mean posterior-to-anterior distances for anteromedial and posterolateral tunnel centre position were 46.8% ± 7.4% and 34.5% ± 5.0% of the posterior-to-anterior height of the medial wall and the mean proximal-to-distal distances for the anteromedial and posterolateral tunnel centre position were 24.1% ± 7.1% and 61.6% ± 4.8%. On the tibial side, the mean anterior-to-posterior distances for the anteromedial and posterolateral tunnel centre position were 28.8% ± 4.3% and 46.2% ± 3.6% of the anterior-to posterior depth of the tibia measured from the anterior border and the mean medial-to-lateral distances for the anteromedial and posterolateral tunnel centre position were 46.5% ± 2.9% and 50.6% ± 2.8% of the medial-to-lateral width of the tibia measured from the medial border. There is high Inter-observer and Intra-observer reliability (Intra-class correlation coefficient). Discussion and conclusionFemoral AM tunnel was positioned significantly anterior and nearly proximal whereas the femoral PL tunnel was positioned significantly anterior and nearly distal with respect to the anatomic site. Location of tibial AM tunnel was nearly posterior and nearly medial whereas the location of tibial PL tunnel was very similar to the anatomic site Evaluation of location of tunnels through the anatomic co-ordinate axes method on 3D CT models is a reliable and reproducible method. This method would help the surgeons to aim for anatomic placement of the tunnels. It also shows that there is scope for improvement of femoral tunnel in double bundle ACL reconstruction through transportal technique.

Clinical effects of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck

Objective: To explore the clinical effects of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck. Methods: From January 2016 to August 2019, 10 male patients, aged from 20 to 52 years with post-burn facial and cervical scar deformities, were admitted to the First People's Hospital of Zhengzhou, with the size of scar ranging from 15 cm×7 cm to 23 cm×11 cm. In the first stage, a cylindrical skin and soft tissue expander with rated capacity ranging from 400 to 600 mL was placed in the frontal-parietal region. Another cylindrical expander with rated capacity ranging from 50 to 100 mL was placed in the temporal region of the patient with scars in front of the ear and in cheek. The injection time was 3 to 5 months with the total injection volume being 1.5 to 2.5 times of the rated capacity of expander. In the second stage, the superficial temporal artery frontal branch and its branches were explored, the expander was removed, the scars in the face and neck were conducted resection and contracture relaxation, and the single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region for reconstruction was performed. When the branches of the superficial temporal vessels were difficult to be detected by Doppler ultrasonic blood stream detector, the patient underwent computed tomography (CT) angiography and three-dimensional reconstruction. The donor site in frontal-parietal region was directly sutured, and the wound of the exposed donor site at the pedicle and temporal region was temporarily covered with scar skin. After the suture wound was healed and the hair in expanded flap grew out, hair removal and laser hair removal were performed. Three to four weeks after transplantation of expanded flap, the flap pedicle was cut off, restored, and trimmed in the third stage. The status about the completion of operation, the implantation of expander in the temporal region, CT angiography and three-dimensional reconstruction were recorded. The effective resection area of expanded flap, the length across the midline and the length of the pedicle, and the survival status of the expanded flap and complications after operation were observed. The appearance of donor and recipient sites, the scar recurrence, the appearance and function improvement of patients, and the satisfaction degree of patients were followed up. Results: All the 10 patients successfully completed three stages of operation, of which 6 patients had an auxiliary expander placement in the temporal region, and 5 patients underwent CT angiography and three-dimensional reconstruction. The effective resection area of expanded flap ranged from 18 cm×8 cm to 25 cm×13 cm. The distal end of the flap across the midline extended 4-6 cm to the opposite side, and the length of pedicle was 2-6 cm. All the expanded flaps of patients survived well after formation and transfer. The venous reflux disorder and obvious swelling occurred in 6 patients at the distal end of the flap after operation, and the blood supply recovered after acupuncture bloodletting, etc. Follow-up of 6 to 24 months showed that the color, texture, and thickness of the expanded flaps were similar to those of the facial skin, and no recurrence of scar was observed; the incision in the donor site of the frontal-parietal region was concealed, the hair growth of the temples and head was normal, and the reconstructed hairline was natural; compared with those before operation, the appearance, head-up, mouth-opening, and other functions of patients were significantly improved; the patients were satisfied with the effect of reconstruction. Conclusions: Clinical application of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck can achieve a good appearance and function, and the donor site shows good shape, which enriches the application range of the trans-regional blood supply flap. It is a reliable method for reconstruction of large scar deformities in the face and neck.

Accuracy on the preoperative assessment of patients with adolescent idiopathic scoliosis using biplanar low-dose stereoradiography: a comparison with computed tomography

BackgroundAlthough computed tomography (CT) is commonly used to diagnose the scoliotic spine in patients with adolescent idiopathic scoliosis (AIS) preoperatively, it is limited by the high radiation and prone scanning position. Recently, a new biplanar stereoradiography (EOS) was used to image the scoliotic spine in an upright posture with significantly less radiation in non-severe AIS subjects. However, its reliability to assess preoperative AIS patients remains unreported. Hence, the purpose of this study is to compare the scoliotic curvature between prone (CT) and upright positions (EOS) in preoperative AIS patients.MethodsThirty-three pre-operative AIS patients (mean age:18.4 ± 4.2) were recruited. EOS was used to scan the whole thoracic spine at upright position. Whereas on the same day, a conventional CT scan was used to evaluate the spine in prone position. The three-dimensional reconstruction of EOS and CT of the spine were then generated. Using previous validated techniques, multiple scoliotic parameters in both modalities were determined. The agreement between the two modalities was compared using the Bland-Altman test, whereas the correlation was assessed by the intraclass correlation coefficient (ICC).ResultsThe mean ICC (prone and upright) of intra-rater/inter-rater reliabilities for the measured parameters were 0.985,0.961/0.969,0.903, respectively. Thoracic Cobb angles, intervertebral wedging and lumbar lordosis correlated significantly between upright EOS imaging radiographs (62.9 ± 9.3°,6.4 ± 2.9° and 48.8 ± 12.4°) and prone CT (47.3 ± 10.0°,5.8 ± 2.7° and 27.9 ± 11.4°; P < 0.001). The apical vertebral wedging and apical intervertebral disc wedging showed a good correlation among the two modalities (upright, 6.5 ± 3.5° and 6.4 ± 2.9°; prone, 6.5 ± 3.6° and 5.8 ± 2.7°; R2 ≥ 0.94; P < 0.01). Similarly, there was significant correlation in apical intervertebral rotation (R2 = 0.834; P < 0.01) between the prone CT (3.4 ± 3.0°) and upright EOS (3.8 ± 3.2°). In addition, the Cobb angle was significantly larger in upright EOS (62.9 ± 9.3°) than in prone CT (47.3 ± 10.0°, P < 0.01) position. There was significant underestimation on scoliotic severity in the prone position when compared with upright position.ConclusionsImportantly, the image acquisition and reconstruction from EOS can better provide accurate three-dimensional spinal representations of the scoliotic curvature in preoperative AIS patients. Moreover, our findings suggested that scoliotic curvatures in preoperative AIS patients can be largely represented by both imaging modalities despite the difference in body positioning.

Three-Dimensional Computed Tomography Reconstruction Unmasks Shunt Disconnection in a Child

Three-Dimensional Computed Tomography Reconstruction Unmasks Shunt Disconnection in a Child

A novel system for accurate lumbar spine pedicle screw placement based on three-dimensional computed tomography reconstruction

ObjectivesThe accuracy of pedicle screw placement strongly affects the outcome of spinal surgery and has mainly relied on the surgeons’ experience. There is no simple, low-cost, and effective pedicle screw placement system to assist new spinal surgeons with less experience. MethodsWe designed a localization system with six parameters (starting point height [SP-H], starting point length [SP-L], transverse section angle, sagittal section angle [SSA], pedicle width [W] and height [H]) based on preoperative computed tomography reconstruction and combined it with the Roussouly classification to guide lumbar spine pedicle screw placement and analysed the change patterns of the six parameters in 50 participants. ResultsBased on the system, we confirmed that combining SP-H and SP-L can localize the entrance of the pedicle screw. Furthermore, we considered that SP-L and transverse section angle would be a new standard for determination of the transverse orientation of the pedicle screw. More importantly, the linear regression equations between H and W and SP-H and H were concealed. In addition, H and W can guide the appropriate selection of pedicle screw. Moreover, change patterns of SSA combined with the Roussouly classification indicate that SSA of L3 can be used as a benchmark to guide the establishment of sagittal alignment of the lumbar spine. ConclusionsUnderstanding and applying the six-parameter localization system are essential for achieving accuracy in lumbar spine pedicle screw placement, and the system is a useful guide in the establishment of sagittal alignment. The translational potential of this articleThis study provides a new pedicle-screw placement system for accurate lumbar spine pedicle screw placement based on three-dimensional CT reconstruction, requiring six parameters to guide the system.

Morphometric analysis of the coracoid process and glenoid width: a 3D-CT study

BackgroundData regarding the parameters of the coracoid process and glenoid width are insufficient, and information on gender, age, and ethnic differences in the parameters appear lacking in the Chinese population. This study aimed to investigate the morphometric parameters in the coracoid process and glenoid width.MethodsUsing our institution’s electronic database, we selected 84 patients (55 males and 29 females) who underwent a shoulder computed tomography (CT) scan from January 2017 to May 2018 in this study. Mimics19.0 software was used for three-dimensional (3D) reconstruction of CT and to measure the morphometric parameters of the coracoid process and glenoid width. Subgroup analyses stratified by gender and age were conducted and the parameters were compared with previously published reports. All data were statistically analysed by SPSS23.0 Statistical Package.ResultsA positive and significant relationship between the coracoid process and the glenoid width (R > 0.758, P < 0.01) was found. The midpoint width represents 52% (41–62%) of the glenoid width; the midpoint height, 40% (31–53%) of the glenoid width. Significant differences in all parameters between males and females were noted (P < 0.05). No significant differences among the age groups were observed (P > 0.05), whereas significant differences in almost all parameters between the ethnic groups were observed (P < 0.05).ConclusionOur results could supplement the information in the shoulder joint database with morphometric parameters and provide a reference for theoretical research on coracoid osteotomy, which may in turn help surgeons in the evaluation of coracoid process transfer.