BackgroundSurgical correction of unilateral cleft lip and palate (UCLP) aims to restore normal facial development and function. Achieving symmetry is essential for dental arch development and facial symmetry. The surgical treatment can result in midfacial retrusion, maxillary constriction, and alveolar segment collapse. The aim of this study was to develop a novel 3D analysis method for assessing possible effects on maxillary arch development following different surgical techniques for lip repair in UCLP patients.MethodsThe dimensions of the maxillary arch were analyzed and compared in children with UCLP who had undergone Delaire or Tennison-Randall/Pfeifer surgery before lip and palate closure using digitized dental plaster casts. Two different evaluation methods were used in the study: the 2D analysis was based on linear measurements using reference points in the OnyxCeph3™ software. The semi-automatic 3D analysis was based on the curve-fitting method and our self-developed customized software application (SMP).ResultsNo significant differences were observed using the 2D method. However, the 3D analysis detected statistically significant differences in the Q coefficient (p = 0.001393) between the two surgical techniques, demonstrating the superior ability of the 3D method to assess morphological changes.ConclusionsThe 3D analysis did not depend on classical reference points. It provided new information for assessing the collapse of maxillary segments. This analysis is a valuable tool for evaluating the impact of surgical techniques on maxillary arch development in children with UCLP. These findings advocate the integration of advanced 3D imaging tools in cleft surgery planning and postoperative assessment.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13005-025-00550-5.

Thoracic endovascular aortic repair (TEVAR) is the predominant treatment for thoracic aortic aneurysms (TAA) due to its superior perioperative outcomes. International guidelines recommend assessing TAA characteristics via computed tomography angiography (CTA). However, the lack of a standardized measurements protocol introduces variability in preoperative planning, and imaging surveillance, and therefore hinders artificial intelligence (AI) integration for fully automated measurements. This study aims to develop and validate a standardized measurement protocol for TAA to improve consistency in measurement and enhance imaging surveillance. A retrospective cohort study was performed at a Dutch tertiary center on patients who underwent TEVAR for a descending TAA from 2010 to 2019. We included degenerative and mycotic TAAs, and exclusions were the lack of a preoperative CTA and/or incomplete postoperative imaging. A standardized measurement protocol was developed based on expert opinion and validated endovascular aortic repair (EVAR) protocols. Imaging analysis utilized dedicated 3D imaging software. The protocol included semi-automated 3D segmentation, center lumen line (CLL) reconstruction, and several measurements, including aortic diameter/volume and sealing lengths. Intraobserver and interobserver agreements were assessed using Bland-Altman analysis and intraclass correlation coefficients (ICCs). We analyzed 133 CTA scans from 31 patients, showing high levels of agreement across measurements, particularly for those repeated by the same observer. Maximum diameter measurements demonstrated excellent consistency, with minimal mean differences for intraobserver and interobserver agreements and excellent correlation (ICC>0.900). Volume measurements were similar consistent, with mean differences of 3.45 (intraobserver) and 2.75 (interobserver) cc. Proximal and distal seal measurements showed good agreement, although interobserver correlation was slightly less consistent. Length of coverage by the endograft exhibited strong consistency. Our standardized measurement protocol for descending TAA offers a consistent approach for preoperative planning, imaging surveillance, and research applications, with high agreement in most measurements. This consistency could reduce variability, enhance imaging surveillance. Future research should focus on external validation, integrating AI to further improve measurement consistency, and simplify TEVAR surveillance.Clinical ImpactThis retrospective study of 133 CTA scans from 31 thoracic endovascular aortic repair (TEVAR) for TAA patients demonstrated excellent measurements consistency, including maximum diameter showing strong agreement and minimal differences in volume measurements. In the absence of an existing measurements protocol, our proposed standardized protocol supports improved preoperative planning, imaging surveillance to further enhance TEVAR surveillance.

Advancing the morphometric analysis of early medieval Slavic pottery: A semi-automated 3D toolset for virtual sections

Durable occlusion after endovascular coiling can be compromised by recanalization, underscoring the need for accurate cerebral aneurysm assessment. Precise volume measurement not only informs treatment decisions and detects subtle aneurysm growth but also refines calculations of packing density, historically linked to occlusion success. This study compares three volume-measurement approaches-traditional two-dimensional (2D) estimation, a semi-automated three-dimensional (3D) technique, and an artificial intelligence (AI)-based 3D method. In this retrospective analysis, 24 aneurysms were assessed using 3D rotational angiography. Manual segmentation by three specialists using ITK-SNAP or mimics served as the reference standard. These results were compared with volumes from a semi-automated 3D platform (Philips Advanced Visualization Workspace), an AI-based tool (RapidAI for Aneurysm), and traditional 2D estimations. Agreement with the reference standard was quantified through Passing-Bablok regression slopes and mean biases. Passing-Bablok slopes for the 2D, Philips, and RapidAI methods were 0.83, 0.87, and 0.94, respectively, while mean biases were -24.7 mm3 (2D), -19.5 mm3 (Philips), and -14.5 mm3 (RapidAI). RapidAI demonstrated the strongest correlation with the reference standard, whereas 2D estimations showed the largest discrepancy. The semi-automated 3D method exhibited intermediate accuracy, potentially influenced by the clinician input required for segmentation. All methods underestimated aneurysm volumes compared to the reference standard, suggesting that inaccurate volume measurements may mask early aneurysm growth. Among the techniques assessed, the AI-based approach provided the closest agreement with the reference, indicating that improved volumetric methods-particularly AI-driven ones-can enhance early detection of aneurysm expansion, guide treatment decisions, and help establish more reliable follow-up strategies for both treated and conservatively managed aneurysms.

To verify the capability of the Segment Anything Model for medical images in 3D (SAM-Med3D), tailored with low-rank adaptation (LoRA) strategies, in segmenting breast tumors in Automated Breast Ultrasound (ABUS) images. This retrospective study collected data from 329 patients diagnosed with breast cancer (average age 54 years). The dataset was randomly divided into training (n = 204), validation (n = 29), and test sets (n = 59). Two experienced radiologists manually annotated the regions of interest of each sample in the dataset, which served as ground truth for training and evaluating the SAM-Med3D model with additional customized modules. For semi-automatic tumor segmentation, points were randomly sampled within the lesion areas to simulate the radiologists’ clicks in real-world scenarios. The segmentation performance was evaluated using the Dice coefficient. A total of 492 cases (200 from the “Tumor Detection, Segmentation, and Classification Challenge on Automated 3D Breast Ultrasound (TDSC-ABUS) 2023 challenge”) were subjected to semi-automatic segmentation inference. The average Dice Similariy Coefficient (DSC) scores for the training, validation, and test sets of the Lishui dataset were 0.75, 0.78, and 0.75, respectively. The Breast Imaging Reporting and Data System (BI-RADS) categories of all samples range from BI-RADS 3 to 6, yielding an average DSC coefficient between 0.73 and 0.77. By categorizing the samples (lesion volumes ranging from 1.64 to 100.03 cm3) based on lesion size, the average DSC falls between 0.72 and 0.77.And the overall average DSC for the TDSC-ABUS 2023 challenge dataset was 0.79, with the test set achieving a sora-of-art scores of 0.79. The SAM-Med3D model with additional customized modules demonstrates good performance in semi-automatic 3D ABUS breast cancer tumor segmentation, indicating its feasibility for application in computer-aided diagnosis systems.

Trypanosoma brucei is a tractable protist parasite for which many genetic tools have been developed to study novel biology. A striking feature of T. brucei is the catenated mitochondrial DNA network called the kinetoplast DNA (kDNA) that is essential for parasite survival and life cycle completion. Maintenance of kDNA requires three independently essential paralogs that have homology to bacterial DNA polymerase I (POLIB, POLIC and POLID). We previously demonstrated that POLIB has a divergent domain architecture that displayed enzymatic properties atypical for replicative DNA polymerases. To evaluate the functional domains required for kDNA replication in vivo, we pursued an RNAi complementation approach based on the widely used tetracycline (Tet) single inducer system. Tet induction of RNAi and complementation with wildtype POLIB (POLIBWT) resulted in a 93% knockdown of endogenous POLIB mRNA but insufficient ectopic POLIBWT expression. This incomplete rescue emphasized the need for a more versatile induction system that will allow independent, tunable, and temporal regulation of gene expression. Hence, we adapted a dual control vanillic acid (Van)-Tet system that can independently control gene expression for robust RNAi complementation. Dual induction with Van and Tet (RNAi + Overexpression) resulted in 91% endogenous POLIB knockdown accompanied by robust and sustained ectopic expression of POLIBWT, and a near complete rescue of the POLIB RNAi defects. To more precisely quantify changes in kDNA size during RNAi, we also developed a semi-automated 3D image analysis tool to measure kDNA volume. Here we provide proof of principle for a dual inducer system that allows more flexible control of gene expression to perform RNAi and overexpression independently or concurrently within a single cell line. This system overcomes limitations of the single inducer system and can be valuable for elegant mechanistic studies in the field.

In archaeological sciences, the macroscopic morphology of distinct dry bone structures, such as tubercles, ridges, epicondyles, and fossae, is routinely used to infer habitual activity patterns in past human populations, extinct hominins, and other animals. This study introduces "Validated Entheses-based Reconstruction of Activity 2.0" (VERA 2.0), a new method for precisely quantifying 3D surface irregularities on enthesis-bearing bone structures. Building on VERA 1.0, first introduced by the same author in 2016 and later named in a 2021 literature review, VERA 2.0 enhances the previous approach by incorporating a semi-automated image segmentation technique that reduces manual input while maintaining accuracy. The method involves selecting a predefined broad bone surface region, after which an algorithm automatically detects subtle surface irregularities (see example video in the step-by-step protocol at dx.doi.org/10.17504/protocols.io.5jyl82z8dl2w/v3). Validation analyses confirm VERA 2.0's precision and reliability for activity reconstruction through intra- and inter-observer repeatability tests, experimental research comparing activity and control laboratory specimens, and analyses of historical human skeletons with extensively detailed long-term occupational data. Moreover, while this anthropological 3D measuring protocol paper cannot and does not aim to analyze the anatomical and histological nature of bone surface irregularities, preliminary anatomical dissection and virtual analysis of a cadaveric thumb enthesis suggest a possible association with attaching muscles and ligaments. Future anatomical and histological research aiming to explore soft-hard tissue interactions could clarify how these identified surface changes exactly relate to the attaching tissues. Overall, VERA 2.0 provides a robust, efficient quantitative tool for inferring activity patterns from skeletal remains, with applications across paleontological, paleoanthropological, and bioarchaeological contexts.

This study introduces a novel semi-automated 3D approach using isometric reflection for evaluating craniofacial symmetry in patients with juvenile idiopathic arthritis. The defects caused in growing patients were analysed either bilaterally or unilaterally at the condyle head, condylar area and the whole hemimandible. Patients were recruited according to inclusion and exclusion criteria, subsequently divided into three groups: unilateral, bilateral and healthy controls. The cone beam of each patient was segmented into three different sections for each hemimandible. The isometric reflection method was applied to each segment, allowing three-dimensional superimposition along with all the volumes. Seventy-two patients aged 16-23 showed a mean reduction of 34.5% in condyle body volume, 34.6% in condyle head and 10.6% in the whole hemi-mandible of unilateral cases. Bilateral cases exhibited more symmetrical patterns compared to unilateral cases (5.1%-14.3%) while healthy controls showed near-perfect symmetry (2.2%-3.8%). Root mean square (RMS) and mean distance across all three mandibular sections confirmed significantly greater deviations in unilateral cases. The new approach allowed for the visual analysis of the 3D asymmetry between the affected side and the normal side and to quantify them numerically. The unilateral involvement might inhibit growth up to the mandibular body, while bilateral involvement showed values similar to healthy controls.

Ductus arteriosus stenting (DAS) is used to palliate infants with ductal-dependent pulmonary blood flow (DD-PBF), however patent ductus arteriosus (PDA) anatomy can be complex and heterogenous. We developed custom, open-source software to model and quantify PDA anatomy. We retrospectively identified 33 neonates with DD-PBF with a CTA before DAS. A novel custom workflow was implemented in 3D Slicer and SlicerHeart to semi-automatically extract centerlines of the course of the PDA and surrounding vessels. 3D ductal length, diameter, curvature and tortuosity were automatically calculated (3D automatic) and compared to manually adjusted 3D measurements (3D semi-automatic), and manual measurements of PDA dimensions in 2D projectional angiograms before and after stent angioplasty. Ductal anatomy was successfully modeled and quantified in all subjects. 3D automatic and semi-automatic measurements of straight-line aortic to pulmonary artery length were not significantly different than 2D measurements. Semi-automatic 3D measurements were similar to 2D measurements of the total length. Minimum and maximum ductal diameters were not significantly different by 3D automatic and 2D measurements, however semi-automatic 3D diameters were significantly larger. Inter-reader reliability of ductal length and diameter was higher with manual adjustment of 3D centerlines compared to standard measurement of 2D angiograms. These differences were consistent across PGE doses between CTA and DAS. Automatic PDA modeling is feasible and efficient, enabling reproducible quantification of ductal anatomy for procedural planning of DAS in patients with DD-PBF. Further development is needed as well as investigation of whether 3D modeling-derived measurements influence procedural duration or outcome.

Radical endoscopic thyroidectomy (ET) offers superior cosmetic outcomes and enhanced visibility of the surgical field compared to open surgery. However, the thyroid's unique physiological functions and intricate surrounding anatomy may result in various surgical complications. Mixed reality (MR), a real-time holographic visualization technology, enables the creation of highly realistic 3D models in the real world and facilitates multiple human-computer interactions. MR can be utilized for both preoperative evaluation and intraoperative navigation. First, semi-automatic 3D reconstruction of the neck from enhanced computed tomography images is performed using 3Dslicer. Next, the 3D model is imported into Unity3D to create a virtual hologram that can be displayed on an MR helmet-mounted display (HMD). During surgery, surgeons can wear the MR HMD to locate lesions and surrounding anatomy through the virtual hologram. In this study, patients requiring radical ET were randomly assigned to either the experimental group or the control group. Surgeons performed MR-assisted radical ET in the experimental group. A comparative analysis of surgical outcomes and the results of scales was conducted.This study successfully developed the neck 3D model and the virtual hologram. According to the NASA Task Load Index Scale, the experimental group exhibited significantly higher scores in 'Own Performance' and lower scores in 'Effort' compared to the control group (p = 0.002). Additionally, on the Likert Subjective Evaluation Scale, the mean scores for all questions exceeded 3. Although the incidence of surgical complications was lower in the experimental group than in the control group, the differences in surgical outcomes were not statistically significant.MR is beneficial for enhancing performance and alleviating the burden of surgeons during the perioperative period. Furthermore, MR has demonstrated the potential to enhance the safety of ET. Therefore, it is essential to further investigate the surgical applications of MR.

Submission Type: Ankle Arthritis Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Re-establishing anatomic ankle and foot alignment is critical to optimize clinical outcomes and longevity of total ankle replacement (TAR). The foot and ankle offset (FAO) is a semiautomatic 3D biometric weight-bearing computed tomography (WBCT) measurement that represents the relationship between the tripod of the foot and the center of the ankle joint. Notably, FAO correlates with increased need of additional procedures in TAR. Yet to our knowledge, no study has utilized FAO to quantify the extent to which TAR can improve alignment in the absence of foot realignment procedures. Our study aims to evaluate associations between preoperative and postoperative FAO and coronal radiograph Tibiotalar Alignment (TTA) for TAR. We hypothesize that TAR alone may significantly improve FAO in patients with ankle deformity. Methods: This study is a single-institution retrospective review of prospectively collected data from primary TARs from March 2022 – November 2023 that obtained preoperative and postoperative (between 4 months and 1 year postoperatively) WBCT scans. Patients who underwent concomitant foot realignment procedures (foot osteotomy or fusion) at the time of primary TAR were excluded. There were 85 ankles that underwent primary TAR during the study period who obtained preoperative and postoperative WBCT scans and radiographs. Excluding 23 ankles with concomitant foot realignment procedures and 7 ankles with inadequate scans, there were 55 ankles included for analysis. Patients were classified as varus, neutral or valgus using the cutoff of 5 degrees for TTA and based on the classification described by Lintz for FAO. Correlation between changes in TTA and FAO was addressed by Pearson`s correlation test. Linear regression was used to investigate the association between changes in TTA with changes in FAO. Results: Changes in TTA had a strong positive correlation (PCC 0.832, p < .0001) with changes in FAO. Every 1 degree of increase in TTA pre to post is associated with 0.367 unit increase in FAO pre to post (R^2 0.693, p < 0.0001). In terms of TAR ability to improve FAO, there was a median pre to post FAO change of 2.66 [-0.11, 5.86] for the varus pre-op FAO group and of − 4.69 [-7.52, -2.985] for the valgus pre-op FAO group. Postoperatively, 80% of patients that had pre-op varus FAO remained varus, while 59% that had pre-op neutral FAO persisted neutral and 22% that had pre-op valgus FAO stayed valgus. 98% of patients had neutral post TTA, confirming coronal alignment improvement with TAR. Conclusion: In this study, with each 1-degree change in TTA, there was a 0.367 change in FAO with a strong positive correlation between the 2D and the 3D measurements. TAR was able to improve FAO in patients with tibiotalar deformity and a more powerful change was noticed in valgus alignment. After TAR, patients with pre-op varus FAO are most likely to remain varus, while patients with valgus pre-op FAO are most likely to improve to neutral FAO. Understanding how FAO changes after TAR can help surgeons predict when an additional procedure could be necessary.

We determined the reliability of a three-dimensional (3D) ultrasound (US) segmentation software for evaluating volumetric hydronephrosis index (HI) and renal parenchymal and pelvicalyceal volume in children with urinary tract dilation (UTD). From 1/2019 to 9/2023, children clinically scheduled for a renal imaging exam to assess UTD at a single center were prospectively enrolled. They underwent a dedicated two-dimensional (2D) and 3D US renal exam. A UTD score was assigned per kidney from the 2D images based on the 2014 consensus classification by an experienced pediatric radiologist. From the 3D dataset, the renal parenchyma and collecting system were independently segmented by three trained raters using a semi-automated software. From this segmentation, the kidney parenchymal and pelvicalyceal volume, dimensions, and volumetric HI values were analyzed using the intraclass correlation coefficient to grade inter-rater reliability. Forty-eight studies from 47 patients were included (65% male; median age 24 months; IQR 61 months). From these, 46 right and 40 left kidneys were chosen based on image quality. Twenty-nine (33.7%) kidneys had no UTD, 10 (11.6%) had UTD P1, 23 (26.7%) had UTD P2, and 24 (27.9%) had UTD P3. Inter-rater reliability was almost perfect across all parameters, with estimates ranging from 0.85 to 0.95. In sub-analysis of kidneys with UTD P2 and UTD P3, volumetric HI had the lowest inter-rater agreement (0.75 and 0.66, respectively). Semi-automated 3D US segmentation for kidneys with UTD can reliably assess renal dimensions, parenchymal and collecting system volumes, and volumetric HI among raters.

In patients with metastatic pancreatic neuroendocrine tumors (PanNETs), the Ki-67 index is objectively assessed by pathologists; however, liver tumor burden (LTB) depends on the subjective judgment of physicians. This study aimed to elucidate the usefulness of the semi-automated 3D volumetric assessment of LTB in patients with PanNET. We retrospectively reviewed 29 patients (40 computed tomographies [CTs]) with metastatic PanNETs. LTB was measured using a semiautomated 3D volumetric software program (volumetric assessment) or evaluated independently by 6 clinicians using CT imaging (visual assessment). The treatment map was classified into 3 groups based on LTB and Ki-67 index. Visual and volumetric assessments of the LTB were well correlated. The LTB was significantly higher on visual assessment than volumetric assessment (P < 0.01). Categorization on the map was consistent between the visual and volumetric evaluations in 23 patients (equal group). The remaining 6 patients were overestimated by visual assessment (overestimated group). Progression-free survival was significantly longer in patients in the 'equal group' than the 'overestimated group' (981 vs 366 days, P < 0.01). This pilot study revealed a good correlation between visual and volumetric assessments, and visual assessment overestimated LTB, compared to volumetric assessment.

Semiautomated Three-Dimensional Landmark Placement on Knee Models Is a Reliable Method to Describe Bone Shape and Alignment

Background/Objectives: To evaluate the clinical performance of two optical coherence tomography angiography (OCTA) devices, including a semi-automated device, with respect to image quality and pathology detection, with fluorescein angiography (FA) and indocyanine green angiography (ICGA) serving as the reference standards. Methods: In this prospective cross-sectional study, normal eyes and those with various retinal and choroidal pathologies were enrolled and underwent OCTA scanning using semi-automated 3D OCT-1 Maestro2 and Cirrus™ HD-OCT 5000 devices, as well as FA/ICGA imaging. OCTA scans and FA/ICGA images were independently graded for image quality and the visibility of prespecified anatomic vascular features, along with the presence or absence of pathology on the OCTA scans and the FA/ICGA images (within regions corresponding to the OCTA scan areas). Positive percent agreement (PPA), defined as the proportion of eyes in which the OCTA demonstrated pathology when the corresponding FA/ICGA showed pathology, and negative percent agreement (NPA), defined as the proportion of eyes in which the OCTA showed no pathology when the FA/ICGA also showed no pathology, were calculated. Results: In total, 38 normal eyes and 86 pathologic eyes were enrolled in the study. The majority of images for both devices were considered clinically useful. The PPA and NPA were high for both devices, indicating a good ability to identify disease when present and to rule it out when not present. Conclusions: The findings of this study suggest that the semi-automated Maestro2 and Cirrus have comparably good clinical performance, particularly with regard to accuracy when identifying vascular pathologies.

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:Charcot-Marie-Tooth (CMT) disease is the most common cause of cavus foot. The complex deformities in cavovarus feet of CMT disease are difficult to evaluate. The bone axes of CMT may be difficult to calculate by conventional weightbearing computed tomography (WBCT). For this reason, 3D automated measurements have been used to assess complex anatomy. The aim of this study was to quantitatively assess deformity correction following joint sparing CMT cavovarus reconstruction surgery. This is the first study investigating preoperative and postoperative WBCT findings in CMT feet using semi-automated 3D measurements.Methods:The study was approved by our institutional review board and informed consent was obtained from all patients. Joint sparing CMT surgery was performed with multiple soft tissue releases and bony procedures. Among the 170 cases from May 2021 to May 2023, twenty-nine CMT patients who had both pre- and postoperative WBCTs were retrospectively analyzed. 3D measurements of WBCT were performed using semi-automated software (Bonelogic 2.1, Disior) to investigate changes in sagittal, axial, and coronal parameters. Pre- and postoperative data was compared using a Wilcoxon signed-ranks test and these data were also compared with normative data using a Welch's t-test. Correlation among these sagittal, axial, and coronal parameters were analyzed using Spearman’s rank correlation coefficient test.Results:The sagittal, axial, and coronal malalignment of the hindfoot, and the sagittal and axial malalignment of the forefoot was significantly improved after corrective surgery (P < .05). Sagittal Meary’s angle (from 14.8 degrees to 0.1 degrees), axial talonavicular angle (TNA, from 3.6 degrees to 19.2 degrees), and coronal hindfoot alignment (from 11.0 degrees to -11.1 degrees) showed significant changes postoperatively (P < .001). Hindfoot, forefoot sagittal and forefoot axial parameters reached comparable outcomes compared to normative value (P > .05). Regarding amount of correction, Spearman’s correlation demonstrated that axial Meary’s angle and TNA were most strongly related to improvement in sagittal Meary’s angle and coronal hindfoot alignment.Conclusion:Preoperative and postoperative WBCT measurements demonstrated that joint sparing CMT cavovarus reconstruction significantly improved sagittal, axial, and coronal deformities of CMT, and sagittal Meary’s angle was restored toward normative values. Apparent axial plane correction, the majority of which occurred at the talonavicular joint, had the strongest correlation with deformity correction in multiple planes. This suggests that soft tissue releases and correction of the talonavicular joint may be a key component of a CMT cavovarus foot correction.Figure. (A) CMT surgery with soft tissue releases and bony procedures, (B) Pre- and postoperative radiographic results, and gross photos of the operated right foot of a 17-year-old male patient.

Category: Ankle; Sports Introduction/Purpose: Subtle syndesmotic instabilities are often under-diagnosed and pose long-term implications for ankle joint health. Previous studies have assessed the diagnostic accuracy of conventional Computed Tomography (CT) in patients with syndesmotic instability. However, these measurements were obtained manually and only at 1 cm proximal to the tibiotalar joint. To fully leverage the three-dimensional (3D) advantages of CT imaging, automated 3D distance mapping algorithms can provide a more comprehensive analysis. Further, while previous studies have demonstrated the sensitivity of these algorithms when analyzing syndesmotic instability using weightbearing CT (WBCT), many clinics do not have access to WBCT. Therefore, the aim of this study was to develop a distance mapping algorithm and scan protocol that can detect subtle syndesmotic instability using the more accessible imaging modality, conventional CT. Methods: Forty-five patients with rotational ankle injuries (21 syndesmotic injuries and 24 lateral collateral ligament injuries) diagnosed via radiologist MRI read, were analyzed. Each patient underwent three ankle CT protocols: neutral position; 45° external rotation with dorsiflexion and extended knees (Stress B); and 45° external rotation with dorsiflexion and flexed knees (Stress C). Semi-automatic CT scan segmentation was performed using a commercially available software, and syndesmosis volume and distances were calculated using MATLAB (Figure 1A). Distance was defined as the normal distance between the tibial subchondral surface and its opposing surface on the fibula or talus. Medial and lateral talar gutters were also studied. The syndesmosis was sectioned at 1 cm, 3 cm, and 5 cm proximal to the tibiotalar joint, and into anterior and posterior regions (Figure 1B). Receiver-operating characteristic (ROC) curves and area under the curve (AUC) were calculated to compare measurements and assess diagnostic accuracy (α = 0.05). Results: Significant differences were observed between syndesmotic and lateral collateral ligament injuries at 1 cm, 3 cm, and 5 cm proximal to the tibiotalar joint under stressed positions. The highest diagnostic accuracy was noted at 1 cm and 3 cm within the syndesmotic incisura, with AUC values of 0.91 for Stress B at 1 cm (Figure 1C), and 0.92 for Stress B and C at 3 cm (Figure 1D). In the anterior syndesmotic incisura, AUCs were 0.83 for Stress B and 0.89 for Stress C at 1 cm (Figure 1E), and 0.85 for Stress B and 0.93 for Stress C at 3 cm (Figure 1F). AUCs of 0.90 for Stress B and 0.83 for Stress C were observed in the posterior gutter medial to the talus. Conclusion: This proposed automated 3D distance mapping CT algorithm, enhanced by external rotational ankle stress maneuvers, demonstrates high diagnostic accuracy in detecting subtle syndesmotic instability, distinguishing well between syndesmotic and lateral collateral ligament injuries. A significant posterior widening at the medial gutter in the syndesmotic injury group may implicate concomitant deltoid ligament injury. Most importantly, however, this study suggests that weightbearing CT may not be essential for diagnosing subtle syndesmotic instabilities and that conventional CT imaging and external rotational stress can allow for high diagnostic accuracy of these injuries. Further validation of this algorithm is warranted to confirm its clinical utility.

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Progressive Collapsing Foot Deformity (PCFD) is a symptomatic, complex, three-dimensional foot deformity that can occur in feet that were previously neutrally aligned or in those with congenital/pediatric flat feet. Once collapsed, it becomes challenging to differentiate the initial foot shape. This study aims to evaluate differences in Weight-Bearing CT (WBCT) parameters among a cohort of symptomatic PCFD patients with a history of pediatric flat foot (= pediatric PCFD), without such a history (= non-pediatric PCFD), and a control group without PCFD. We hypothesized that pediatric PCFD would display distinct WBCT parameters compared to non-pediatric PCFD, particularly with less forefoot abduction and middle facet subluxation. Furthermore, we sought to identify which parameters are the most predictive of pediatric PCFD. Methods: This retrospective comparative study included adult patients with symptomatic PCFD. Pediatric PCFD was defined as patients with flat feet since childhood, and non-pediatric PCFD was defined as patients with no history of childhood flat foot. A total of 37 symptomatic pediatric PCFD patients were compared to 52 symptomatic non-pediatric PCFD patients and 11 control patients. All patients underwent foot/ankle WBCT scans. Using dedicated software, both manual and semi-automated 3D measurements were carried out for the various PCFD deformity categories (A-Hindfoot Valgus, B-Abduction, C-Arch Collapse, and D-Peritalar Subluxation). The data underwent normality testing with the Shapiro-Wilk method, and comparisons were made via Paired T-tests or Paired-Wilcoxon tests. A p-value threshold of 0.05 or below was deemed significant. To determine which factors affect the presence of rigidity in PCFD, a multivariate nominal regression analysis was conducted. A partition prediction model was employed to identify threshold values that most accurately determine “pediatric PCFD”. Results: All parameters showed significant differences compared to control, except for BMI. Compared to non-pediatric PCFD, the pediatric PCFD group showed significantly less deformity in classes A, B, C, and D (all p&lt; 0.002) and became symptomatic at a younger age (p&lt; 0.001). Compared to controls, pediatric PCFD measurements for HMA (p=0.053) and SF (p=0.07) were not statistically significant. Multivariate analysis indicated that axial TFM (p=0.005), MFS (p=0.013), and ST (p=0.03) were the best predictors of pediatric PCFD (R2: 0.27). The partition prediction model showed that an ST distance &gt;0.24 mm, axial TFM &gt;24.28, and MFS &gt;43.7% can rule out pediatric PCFD with 95% confidence. Conclusion: This study showed that symptomatic pediatric PCFD presents with distinct WBCT parameters compared to symptomatic non-pediatric PCFD, notably exhibiting less forefoot abduction, less middle facet subluxation, and less hindfoot malalignment and seems to become symptomatic at a younger age. ST distance &gt;0.24 mm, axial TFM &gt;24.28, and MFS &gt;43.7% could rule out a PCFD with “pediatric origin.” These results suggest that a different threshold should be set to assess PCFD in patients with flat feet since childhood.

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Midfoot arthritis (MA) and progressive collapsing foot deformity (PCFD) are both entities characterized by biomechanical changes of the foot leading to collapse of the medial arch. The effect of PCFD on peritalar dislocation/subluxation has been described extensively and is a critical consideration in preoperative planning of deformity correction. While midfoot arthritis has been previously associated with subluxation of the midfoot joints such as the naviculocuneiform and tarsometatarsal joints, no studies have evaluated the effect of midfoot arthritis medial column collapse on peritalar parameters. The primary objective of this study was to compare the extent of medial arch collapse in MA and PCFD and correlate these parameters with peritalar changes. Methods: This is a retrospective comparative study identifying patients with PCFD and MA. PCFD was defined as a known history of flatfoot deformity and symptomatic progression of medial arch collapse. Midfoot arthritis was identified through radiological findings along with patient-reported symptomatic medial arch collapse. Patients with both flat foot deformity and radiological findings of midfoot arthritis were excluded. All patients underwent foot/ankle Weightbearing computed tomography (WBCT). Manual and semi-automated 3D measurements of the middle facet subluxation percentage, middle facet incongruence angle, foot &amp; ankle offset, forefoot arch angle, and transverse arch plantar angle were performed. Measurements were done independently by two fellowship-trained readers. Variables were assessed for normality (Shapiro-Wilk) and compared using Paired T-tests or Wilcoxon signed rank test. P-values of 0.05 or less were considered significant. Results: A total of 28 feet were analyzed (14 extremities with PCFD and 14 extremities with MA). The difference in middle facet subluxation percentage and middle facet incongruence angle were statistically significant between the 2 groups favoring more peritalar subluxation in the PCFD group as compared to the MA group (38 vs 14.1 p-value &lt; 0.001 and 12.5 vs 4.1 p-value &lt; 0.001, respectively). The forefoot arch angle was significantly lower in the PCFD group (2.8 vs 6.6, p-value &lt; 0.005) No significant difference was identified in the transverse arch plantar angle between the groups (125.5 vs 121.6, P-value: 0.2). Conclusion: In this retrospective comparative study, midfoot arthritis was found to have a limited effect on peritalar parameters in the setting of medial arch collapse. This study demonstrated that the deformity associated with midfoot arthritis is confined to the medial column and does not affect peritalar subluxation, unlike PCFD. These data demonstrate for the first time that midfoot arthritis and PCFD require distinct approaches in order to address medial column stability in order to achieve the required restoration in foot alignment.

IDH-mutant glioma is classified as oligodendroglioma or astrocytoma based on 1p19q-codeletion. Whether prognostic factors are similar between these tumor types is not well understood. Retrospective cohort study. Molecular characterization was performed with targeted next-generation sequencing. Tumor volumes were calculated using semiautomatic 3D segmentation on all pre- and post-operative MRI scans. Overall survival was assessed with the Cox-proportional hazards model. A total of 383 patients with newly diagnosed IDH-mutant glioma were followed up for a median of 7.2 years. Grades 3 and 4 patients had significantly lower Karnofsky performance, with tumors having more contrast enhancement. Patients also received more aggressive postsurgery treatment. Postoperative tumor volume is significantly and independently associated with survival (HR, per cm3 1.19; 95% CI, 1.03-1.39) in IDH-mutant glioma. A separate analysis of oligodendroglioma and astrocytoma showed a significant association of postoperative tumor volume in astrocytoma but not in oligodendroglioma. Higher age and histologic tumor grade were associated with worse survival in patients with oligodendroglioma but not with astrocytoma. Our data support an initial strategy of extensive resection in patients with oligodendroglioma and astrocytoma. Other important prognostic factors differ between these tumor types, urging researchers and clinicians to keep treating these tumors as separate entities.