3D CT Research Articles

Stress shielding influences shoulder function after reverse shoulder arthroplasty using a short stem at minimum 2 years follow-up and can be predicted using a preoperative planning software: A retrospective cohort study

Background The aim of the study was to assess if 3D CT-scan-based planification of distal filling ratio (DFR) is accurate when compared to postoperative DFR calculated on plain X-rays. A secondary aim was to investigate if an association between clinical outcomes and the degree of stress shielding (SS) exists. Methods Fifty patients with short-stem reverse shoulder arthroplasties, preoperative CT scans, and a minimum 24-month radiographic follow-up were included in the study. At 24 months follow-up, all patients were evaluated by assessing the postoperative filling ratios, the 3D DFRs, the simple shoulder test, Constant-Murley score, and visual analogue scale through a prospectively data collection and statistically analyzed. Results A correlation between the 3D DFR and SS onset (rs 0.54; P < 0.001), and between postoperative DFR and SS (rs 0.71; P < 0.001), was found. The 3D DFR and the postoperative DFR were correlated (rs 0.89; P < 0.0001). SS negatively affects the postoperative range of motion, decreasing the forward elevation of the shoulder. Conclusion The calculation of DFR based on 3D CT planning is a good predictor of humeral SS after short-stem RTAs. The presence of SS decreases clinical outcomes by lowering the anterior elevation of the shoulder. Level of evidence Case series.

A Refined Approach to Segmenting and Quantifying Inter-Fracture Spaces in Facial Bone CT Imaging

The human facial bone is made up of many complex structures, which makes it challenging to accurately analyze fractures. To address this, we developed advanced image analysis software which segments and quantifies spaces between fractured bones in facial CT images at the pixel level. This study used 3D CT scans from 1766 patients who had facial bone fractures at a university hospital between 2014 and 2020. Our solution included a segmentation model which focuses on identifying the gaps created by facial bone fractures. However, training this model required costly pixel-level annotations. To overcome this, we used a stepwise annotation approach. First, clinical specialists marked the bounding boxes of fracture areas. Next, trained specialists created the initial pixel-level unrefined ground truth by referencing the bounding boxes. Finally, we created a refined ground truth to correct human errors, which helped improve the segmentation accuracy. Radiomics feature analysis confirmed that the refined dataset had more consistent patterns compared with the unrefined dataset, showing improved reliability. The segmentation model showed significant improvement in the Dice similarity coefficient, increasing from 0.33 with the unrefined ground truth to 0.67 with the refined ground truth. This research introduced a new method for segmenting spaces between fractured bones, allowing for precise pixel-level identification of fracture regions. The model also helped with quantitative severity assessment and enabled the creation of 3D volume renderings, which can be used in clinical settings to develop more accurate treatment plans and improve outcomes for patients with facial bone fractures.

Assessing the Wrightington Classification System for elbow fracture-dislocations : an external reliability study.

Complex elbow fracture-dislocations often result in suboptimal outcomes and necessitate a thorough understanding of injury patterns to guide effective management and reduce adverse sequelae. The Wrightington Classification System (WCS) offers a comprehensive approach and considers both bony and soft-tissue disruption, providing clearer guidance for treatment. This is the first external study to assess the reliability of the WCS for elbow fracture-dislocations. A blinded study of patients with elbow fracture-dislocations at a single institution between December 2014 and December 2022 was conducted. Five assessors with a range of experience, including orthopaedic surgeons and radiologists, independently classified injuries using the WCS across three image methods: plain radiograph, 2D CT, and 2D and 3D CT reconstruction images, on two occasions with an eight-week interval. Interobserver and intraobserver reliability were evaluated using kappa statistics and the Landis and Koch criteria. A total of 73 patients were included in the study. Interobserver reliability was moderate, with mean kappa values of 0.518 (95% CI 0.499 to 0.537), 0.557 (95% CI 0.537 to 0.577), and 0.582 (95% CI 0.562 to 0.601), for radiographs, 2D CT, and 2D and 3D CT reconstructions, respectively. Intraobserver agreement was substantial (mean kappa 0.695 (SE 0.067), 0.729 (SE 0.071), and 0.777 (SE 0.070) for radiographs, 2D CT, and 3D CT reconstructions, respectively). The WCS is a reliable and valuable tool for characterizing elbow fracture-dislocations and guiding surgical interventions. This study found moderate reliability in using the WCS, with higher reliability with combined 2D and 3D CT imaging. Further refinement within the WCS in differentiating between coronoid avulsions, basal, anteromedial, and/or anterolateral facet injuries may help improve reliability and reproducibility.

Three-dimensional volumetric CT image fusion and trans-abdominal US: Adjunct guidance to portal vein cannulation for TIPS

PurposeTo describe portal vein cannulation under adjunct guidance for transjugular intrahepatic portosystemic shunts (TIPS). MethodsMedical records of 86 patients who underwent TIPS, including conventional TIPS, 3D volumetric CT image fusion (CT-fluoroscopy image fusion)-guided TIPS, and transabdominal ultrasound (US)-guided TIPS at our institute from March 2016 to June 2024 were reviewed. Baseline characteristics, clinical outcomes, and procedural data were analyzed. ResultsTechnical success was achieved in 35 conventional TIPS patients (92.11 %), 20 CT-fluoroscopy image fusion-guided TIPS patients (95.24 %), and 26 transabdominal US-guided TIPS patients (96.30 %). Among patients who underwent a successful procedure, the procedural time and contrast usage were lower in the CT-fluoroscopy image fusion-guided and trans-abdominal US-guided TIPS groups than in the conventional group. There was a statistical significance in the cumulative fluoroscopic time between CT-fluoroscopy image fusion-guided TIPS and conventional TIPS groups (43.19 ± 14.92 vs 63.05 ± 30.33 min, p = 0.012). No immediate experienced complications were observed. Furthermore, the incidence of post-procedural complications among the three groups was not statistically different during follow-up. ConclusionsCT-fluoroscopy image fusion and trans-abdominal US-guided portal vein cannulation are feasible, safe, and effective adjunct methods for patients undergoing TIPS. These methods provide shorter procedural time and lower contrast usage for TIPS placement.

Potential for reduction of radiation dose in the assessment of the lead orientation in directional deep brain stimulation electrodes.

Directional deep brain stimulation (dDBS) relies on electrodes steering the stimulation field in a specific direction. Post implantation, however, the intended and real orientation of the lead frequently deviates e.g. due to torque of the electrode. The orientation is assessed by postoperative imaging such as C-arm cone-beam CT (CBCT) using 3D rotational fluoroscopy and multi-slice CT (MSCT). The objective is to determine the effect of different X-ray systems such as CBCT and MSCT, and scan acquisition parameters on effective radiation doses. We retrospectively investigated the dose area product (DAP) and dose length product (DLP) of patients who underwent both CBCT and MSCT after dDBS surgery. These metrics were then converted into the effective dose by established conversion coefficients. For CBCT, the feasible dose optimization by collimation was virtually assessed. Univariate analysis was performed to determine differences. Among 88 patients median effective dose was 0.20±0.07mSv in CBCT and 2.11±0.33mSv in MSCT (p<0.001). The field of view (FOV) in CBCT can be collimated in craniocaudal orientation by 33.6% and mediolaterally by 60.8%. This optimized collimation implies an effective dose reduction of 76% (p<0.001). Comparison of the effective dose of MSCT vs. CBCT revealed a significant dose reduction by 90.3% (p<0.001), whereas optimal collimation by 97.7% (p<0.001). For assessment of dDBS orientation, CBCT had significantly lower radiation doses compared to MSCT. Optimized collimation in CBCT allows for a further substantial dose reduction. Moreover, the proposed approach is applicable on other neuroimaging procedures such as 3D visualization of treated intracranial aneurysm.

Cone-Beam CT Segmentation for Intraoperative Electron Radiotherapy Based on U-Net Variants with Transformer and Extended LSTM Approaches

AI applications are increasingly prevalent in radiotherapy, including commercial software solutions for automatic segmentation of anatomical structures for 3D CT. However, their use in intraoperative electron radiotherapy (IOERT) remains limited. In particular, no AI solution is available for contouring cone beam CT (CBCT) images acquired with a mobile CBCT device. The U-Net convolutional neural network architecture has gained huge success for medical image segmentation but still has difficulties capturing the global context. To increase the accuracy in CBCT segmentation for IOERT, three different AI architectures were trained and evaluated. The features of the natural language processing models Transformer and xLSTM were added to the popular U-Net architecture and compared with the standard U-Net and manual segmentation performance. These networks were trained and tested using 55 CBCT scans obtained from breast cancer patients undergoing IOERT in the department of radiotherapy and radiation oncology in Salzburg, and each architecture’s segmentation performance was assessed using the dice coefficient (DSC) as a similarity measure. The average DSC values were 0.83 for the standard U-Net, 0.88 for the U-Net with transformer features, and 0.66 for the U-Net with xLSTM. The hybrid U-Net architecture, including Transformer features, achieved the best segmentation accuracy, demonstrating an improvement of 5% on average over the standard U-Net, while the U-Net with xLSTM showed inferior performance compared to the standard U-Net. With the help of automatic contouring, synthetic CT images can be generated, and IOERT challenges related to the time-consuming nature of 3D image-based treatment planning can be addressed.

Quantitative characterisation of microporous ceramic emitters microstructure and visualisation of seepage based on CT 3D reconstruction

Quantitative characterisation of microporous ceramic emitters microstructure and visualisation of seepage based on CT 3D reconstruction

3D synthetic CT patch generation and reconstruction by using multi-resolution generative adversarial network

3D synthetic CT patch generation and reconstruction by using multi-resolution generative adversarial network

Single right sided traumatic avulsion fracture of both ASIS and AIIS: case review

Introduction and importance: Simultaneous avulsion fractures of the anterior superior iliac spine (ASIS) and anterior inferior iliac spine (AIIS) are rare, typically resulting from intense muscular contractions in athletes. Accurate diagnosis requires thorough examination and imaging. Case presentation: A 29-year-old male sustained right-sided ASIS and AIIS avulsion fractures from a road traffic accident. Diagnosis was confirmed via plain radiographs and 3D CT scans. The patient underwent surgical fixation with cannulated cancellous screws. He fully recovered and resumed pre-injury sports activity within 5 months. Clinical discussion: ASIS and AIIS avulsion fractures are uncommon, with simultaneous occurrences being even rarer. Proper diagnosis and surgical intervention are crucial, especially in active patients with significant displacement. Conclusion: Surgical treatment using cannulated cancellous screws led to complete recovery and return to sports activity in this case, highlighting the effectiveness of this approach for managing complex avulsion fractures.

Ejtm3 experiences after ChatGPT and other AI approaches: values, risks, countermeasures.

We invariably hear that Artificial Intelligence (AI), a rapidly evolving technology, does not just creatively assemble known knowledge. We are told that AI learns, processes and creates, starting from fixed points to arrive at innovative solutions. In the case of scientific work, AI can generate data without ever having entered a laboratory, (i.e., blatantly plagiarizing the existing literature, a despicable old trick). How does an editor of a scientific journal recognize when she or he is faced with something like this? The solution is for editors and referees to rigorously evaluate the track records of submitting authors and are doing. For example, false color evaluations of 2D and 3D CT and MRI images have been used to validate functional electrical stimulation for degenerated denervated muscle and a home Full-Body In-Bed Gym program. These have been recently published in Ejtm and other journals. The editors and referees of Ejtm can exclude the possibility that the images were invented by ChatGPT. Why? Because they know the researchers: Marco Quadrelli, Aldo Morra, Daniele Coraci, Paolo Gargiulo and their collaborators as well! Artificial intelligence is not banned by the EJTM, but when submitting their manuscripts to previous and to a new Thematic Section dedicated to AI in Translational Mobility Medicine authors must openly declare whether they have used artificial intelligence, of what type and for what purposes. This will not avoid risks of plagiarism or worse, but it will better establish possible liabilities.

LNQ 2023 challenge: Benchmark of weakly-supervised techniques for mediastinal lymph node quantification

Accurate assessment of lymph node size in 3D CT scans is crucial for cancer staging, therapeutic management, and monitoring treatment response. Existing state-of-the-art segmentation frameworks in medical imaging often rely on fully annotated datasets. However, for lymph node segmentation, these datasets are typically small due to the extensive time and expertise required to annotate the numerous lymph nodes in 3D CT scans. Weakly-supervised learning, which leverages incomplete or noisy annotations, has recently gained interest in the medical imaging community as a potential solution. Despite the variety of weakly-supervised techniques proposed, most have been validated only on private datasets or small publicly available datasets. To address this limitation, the Mediastinal Lymph Node Quantification (LNQ) challenge was organized in conjunction with the 26th International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI 2023). This challenge aimed to advance weakly-supervised segmentation methods by providing a new, partially annotated dataset and a robust evaluation framework. A total of 16 teams from 5 countries submitted predictions to the validation leaderboard, and 6 teams from 3 countries participated in the evaluation phase. The results highlighted both the potential and the current limitations of weakly-supervised approaches. On one hand, weakly-supervised approaches obtained relatively good performance with a median Dice score of 61.0%. On the other hand, top-ranked teams, with a median Dice score exceeding 70%, boosted their performance by leveraging smaller but fully annotated datasets to combine weak supervision and full supervision. This highlights both the promise of weakly-supervised methods and the ongoing need for high-quality, fully annotated data to achieve higher segmentation performance.

A Method for Calculating Small Sizes of Volumes in Postsurgical Thyroid SPECT/CT Imaging

Differentiated thyroid cancer treatment typically involves the surgical removal of the whole or largest part of the thyroid gland. Diagnostic procedures are useful both before and after treatment to determine the need for radioiodine ablation, re-stage the disease, monitor disease progression, or evaluate treatment efficacy. SPECT/CT imaging can be utilized to identify small, distant iodine-avid metastatic lesions and assess their uptake and volume for the above purposes as well as for performing lesion-based dosimetry when indicated. The objective of this study was to develop and validate a method for calculating small sizes of volumes in SPECT/CT imaging as well as to perform calculations utilizing I-131 and I-123 postsurgical SPECT/CT images from a neck–thyroid phantom. In this approach, the calculated volume was unaffected by radiation spillover from high-uptake voxels since it was the result from the successive application of the gray-level histogram technique to SPECT and CT 3D matrices. Beforehand, the SPECT 3D matrix was resized and aligned to the corresponding CT one. The method was validated following the clinical protocols for postsurgical thyroid imaging by using I-123 and I-131 scatter and attenuation-corrected SPECT/CT images from a neck–thyroid phantom. The phantom could accommodate two volumes of different sizes (0.5, 1, 1.5, 3, and 10 mL) and enclose anatomical tissue-equivalent main scattering structures. For the 0.5 and 10 mL volumes, the % differences between the actual and the calculated volumes were 15.2% and 1.2%, respectively. Radiation spillover was only present in SPECT images, and it was more profound at higher administered activities, in I-131 than in I-123 images, and in smaller volumes. When SPECT/low-dose-CT imaging is performed, this method is capable of accurately calculating small volumes without the need of additional modalities.

Impact of Deep Learning 3D CT Super-Resolution on AI-Based Pulmonary Nodule Characterization

Background/Objectives: Correct pulmonary nodule volumetry and categorization is paramount for accurate diagnosis in lung cancer screening programs. CT scanners with slice thicknesses of multiple millimetres are still common worldwide, and slice thickness has an adverse effect on the accuracy of the pulmonary nodule volumetry. Methods: We propose a deep learning based super-resolution technique to generate thin-slice CT images from thick-slice CT images. Analysis of the lung nodule volumetry and categorization accuracy was performed using commercially available AI-based lung cancer screening software. Results: The accuracy of pulmonary nodule categorization increased from 72.7 percent to 94.5 percent when thick-slice CT images were converted to generated-thin-slice CT images. Conclusions: Applying the super-resolution-based slice generation on thick-slice CT images prior to automatic nodule evaluation significantly increases the accuracy of pulmonary nodule volumetry and corresponding pulmonary nodule category.

Postoperative accuracy quantification of corrective osteotomies: standardisation of Q3D-CT methodology

PurposeCurrently, no gold standard exists for 3D analysis of virtually planned surgery accuracy postoperatively. The aim of this study was to present a new, validated and standardised methodology for 3D postoperative assessment of surgical accuracy in patients undergoing 3D virtually planned and guided corrective osteotomies.MethodsAll patients who underwent 3D planned corrective osteotomy in 2021–2022 at our center with a postoperative CT were included. Postoperative surgical outcome was analysed with a postoperative CT and compared to the preoperative virtual surgical planning to determine achieved accuracy. Validation of the analysis was performed by evaluating the individual assessment of six experienced observers. A postoperative quantification was performed according to the proposed innovative methodology based on rotation axes of a virtual postoperative bone model aligned to the virtual preoperative bone model and virtual surgical planned bone model. To evaluate the intra-observer variability, one observer performed the assessment twice.ResultsQuantification of 13 patients according resulted in measurements with a median range (and its interquartile range) for 3D translation of: 2.43 mm (3.17), for the angle deviations: 3D rotation, 2D coronal, 2D sagittal and 2D axial were: 0.66° (1.66°), 0.74° (0.44°), 0.99° (1.27°), 2.37° (5.00°), respectively. The inter- and intraobserver reliability established with the Intraclass correlation coefficient was for all measurements excellent (> 0.76).ConclusionThe proposed 3D CT technique provides an significant more accurate and objective method for assessment of surgical outcome of a guided corrective osteotomy. The present proposed novel methodology showed excellent inter- and intra-observer reliability with clinically acceptable absolute surgical outcome measurements.

Comparison of facial asymmetry assessment by frontal teleradiography and 3D imaging

The diagnostic approach to facial asymmetries is classically based, in addition to the clinical examination, on a cephalometric analysis carried out on a frontal radiography. Planning of orthognathic surgery requires a three-dimensional (3D) examination to visualize deformities. Nevertheless, the use of cephalometric analysis on 3D imaging remains clinically modest. The main objective of this study was to compare the cephalometric measures obtained from frontal radiographies and 3D imaging in patients with facial asymmetries. Frontal radiographies and 3D CT scans used for orthognathic surgery planning of 24patients with asymmetries were selected. Cephalometric points were manually placed on 2D and 3D images by an operator, twice at a 4-week interval. The asymmetry of the subjects was quantified from 12 measurements, then the data obtained in 2D and 3D was compared. Intra-examination repeatability has been calculated. 2D-3D average differences above 2mm were found in the quantification of mandibular, jugal and maxillary molar symmetry and in the measurements of mandibular symmetry. The 3D measures showed a better repeatability than the 2D measures. The 2D-3D variations observed could have a clinical impact in the diagnosis and management of patients with facial asymmetries. Other studies remain necessary to provide more clinical evidence of the benefits of 3D cephalometry.

Characterization of the Pore Network of a Cohesive Oxisol Through Morphological and Pore Complexity Analyses

Cohesive Oxisols are a type of soil common in the Coastal Plateau in Brazil. These soils represent a challenge for agriculture and their study is fundamental to better land use. There have been a few studies on the porous system of cohesive soils on the micrometer scale. Our study aimed to provide a detailed analysis of the pore complexity of the cohesive horizon of a Brazilian Oxisol using 3D images (volumetric data reconstructed by 2D CT slices) and to correlate these parameters with soil physical–hydric attributes. For this purpose, images with two different resolutions were analyzed from multifractal, lacunarity, and entropy analyses. Additionally, a characterization of hydraulic properties was carried out based on a soil water retention curve (SWRC). No differences were observed between the resolutions for the different physical parameters analyzed. The lacunarity analysis showed a greater homogeneity of the pore system with pores grouped in clusters. The multifractal analysis showed fractal characteristics for the cohesive horizon, suggesting a more homogeneous pore distribution. The main results obtained from the SWRC showed a low available water content due to the predominance of ultramicropores. Overall, the results show a less complex pore system, indicating the presence of pores of small sizes, affecting the water retention and conduction through the soil.

Research on the analysis of morphological characteristics in pediatric femoral neck fractures utilizing 3D CT mapping.

Proximal femoral fractures in children are challenging in clinical treatment due to their unique anatomical and biomechanical characteristics. The distribution and characteristics of fracture lines directly affect the selection of treatment options and prognosis. Pediatric proximal femur fractures exhibit distinctive features, with the distribution and characteristics of the fracture line playing a crucial role in deciding optimal treatment. The study aims to investigate the morphological characteristics of pediatric femoral neck fracture (FNF) from clinical cases by fracture mapping technology and to analyze the relationship between fracture classifications and age. The CT data were collected from 46 consecutive pediatric inpatients' diagnoses of FNF from March 2009 to December 2022. The fracture imaging was reconstructed in three dimensions and performed the simulated anatomical reduction by Mimics and 3-matic. Both Delbet classification and Pauwels angle classification were documented according to the fracture line in each patient. Furthermore, all of the fracture lines in these patients were superimposed to form a fracture map and a heat map. This study included 24 boys and 22 girls (average age, 9.61 ± 3.17years (4 to 16years)). The fracture lines of the anterior and superior femoral neck were found to be mainly located in the middle and lower regions of the femoral neck, while fracture lines of the posterior and inferior neck were mainly concentrated in the middle region. Most children younger than 10years had Delbet type III of fracture (69%), whereas those older than 10years had Delbet type II of fracture (73%). Furthermore, most children had Pauwels angle type III of fracture (63%), especially in those over 10years old (80%) (p = 0.0001). FNF in children is predominantly located in the middle and lower regions of the neck. Older children may be prone to be affected with higher fracture location of FNF or unstable type of fracture.

3D CT to 2D X-ray image registration for improved visualization of tibial vessels in endovascular procedures

3D CT to 2D X-ray image registration for improved visualization of tibial vessels in endovascular procedures

Three-dimensional CT a Valuable Tool in Airway Assessment – How Manoeuvres and Positioning Result in False Measurements!

Three-dimensional computerised tomography (3D CT) reconstruction is an emerging technique of advanced airway imaging useful for pre-operative airway assessment. Several parameters on CT have been studied and mentioned in the literature as the predictors of difficult airway. Head-and-neck CT scans done by surgeons preoperatively to know the extent of tumour can be useful for airway assessment. Herein, we describe two cases where manoeuvres and patient positioning while undergoing CT scan affected measurements of certain parameters.

Posterior Decompression Surgery for Degenerative Lumbar Disease:Basic Principles and Advantages/Disadvantages of Exoscopic Surgery

This paper examines advancements in minimally invasive posterior decompression techniques for lumbar degenerative diseases. It focuses on the unilateral approach for bilateral decompression and bilateral approach for contralateral decompression, in which the entry side is determined independently of the symptomatic side to achieve a facet joint preservation rate of ≥ 70%, while also emphasizing contralateral foraminal decompression(CFD). These techniques address spinal instability by minimizing facet joint resection, reducing postoperative instability. CFD is noteworthy because it enables single-stage decompression in the same surgical field as foraminal stenosis, which frequently coexists with spinal canal stenosis. Additionally, this paper discusses the effectiveness of real-time 3D CT navigation in enhancing surgical precision, especially in complex cases, to improve long-term outcomes by minimizing postoperative instability. Furthermore, exoscopic surgery is evaluated as a future standard, highlighting its superior ergonomics and flexible viewing angles, including steep oblique angles, which are challenging with conventional microscopes. Although exoscopic technology offers many advantages, it also has certain drawbacks and remains in the developmental stage; however, it holds the potential to become a new paradigm in spinal surgery. Balancing minimally invasive approaches with spinal stability remains critical for optimizing patient recovery, reducing complications, and minimizing reliance on spinal fusion surgery.