3D Volume Measurement Research Articles

Evaluation of the Effect of Topical Prostaglandin Analog Treatment on Orbital Structures in Open-Angle Glaucoma with Computed Tomography

Background/Objectives: This study aims to evaluate the computed tomography (CT) scans of glaucoma patients using prostaglandin analogs (PGA) in one eye, investigate findings associated with prostaglandin-associated periorbitopathy (PAP), and compare these findings with those of the contralateral eyes. Methods: Patients with open-angle glaucoma who had CT images of the orbital region taken for another reason at least one month after starting PGA treatment in one eye were included in the study. Enophthalmos measurements from thin-slice CT images, along with 3D volume measurements of orbital fat tissue, periorbital muscles, and the optic nerve, were performed. Ophthalmological examination findings and treatment information were collected. The values were compared with those of the contralateral eyes of the same patients not using PGA. Intraclass correlation coefficients (ICCs) were computed to evaluate measurement repeatability. Results: Forty patients were included in the study. Among them, 29 (72.5%) used latanoprost, 9 (22.5%) used bimatoprost, and 2 (5%) used travoprost. The mean enophthalmos values on the treated side (15.5 ± 2.0 mm) were lower than on the untreated side (16.1 ± 1.4 mm), but this difference was not statistically significant (p = 0.07). In 29 patients (72.5%), enophthalmos measurements were smaller on the treated side, with 7 patients (17.5%) showing a difference of 2 mm or more. No significant correlation was found between the duration of PGA use and enophthalmos measurements (p = 0.768 r = −0.048). Additionally, no significant differences were found in orbital fat volume, total extraocular muscle volume, and optic nerve volume (p > 0.05). ICC values demonstrated excellent reliability (ICC > 0.75) for all measurements. Conclusions: We did not find significant differences in enophthalmos measurements, orbital fat volume, total muscle volume, and optic nerve volume between the PGA-treated and untreated eyes.

3D reconstruction and volume measurement of irregular objects based on RGB-D camera

Abstract To address the challenge of measuring volumes of irregular objects, this paper proposes a volume measurement method based on 3D point cloud reconstruction. The point clouds of the object with multiple angles are obtained from an RGB-D camera mounted on a robotic arm, and then are reconstructed to form a whole complete point cloud to calculate the volume of the object. Firstly, the robotic arm is controlled to move to four angles for capturing the original point clouds of the target. Then, by using the rotation and translation matrices obtained from the calibration block pre-registration, the point clouds data from the four angles are fused and reconstructed. Subsequently, the issue of missing bottom point cloud data is addressed using a bottom-filling algorithm. Following this, the efficiency of the point cloud volume calculation algorithm is enhanced through the application of AABB filtering. Finally, the reconstructed point cloud volume is calculated using a slicing algorithm that integrates 2D point cloud segmentation and point cloud sorting. Experimental results show that this method achieves a volume measurement accuracy of over 95% for irregular objects and exhibits good robustness.

A Dietary Supplement in the Management of Patients with Lumbar Osteochondrosis: A Randomized, Double-Blinded, Placebo-Controlled Study.

Various nutritional supplements are available over the counter, yet few have been investigated in randomized controlled trials. The rationale for using the specific mix of nutritional substances including collagen type II, hyaluronic acid, n-acetyl-glucosamine, bamboo extract, L-lysine, and vitamin C is the assumption that combining naturally occurring ingredients of the intervertebral disc would maintain spine function. This double-blinded, placebo-controlled randomized trial aimed to evaluate the efficacy of a nutraceutical supplement mix in the management of lumbar osteochondrosis. Fifty patients were randomly assigned to either the supplement or placebo group in a 1:1 ratio. Patient-Reported Outcome Measures (PROMs) included the Oswestry Disability Index (ODI), the visual analogue scale for pain (pVAS), short form-12 (SF-12) physical and mental component summary subscale scores (PCS and MCS, respectively), and global physical activity questionnaire (GPAQ). Magnetic resonance imaging (MRI) was used to evaluate degenerative changes of intervertebral discs (IVD) including Pfirrmann grades as well as three-dimensional (3D) volume measurements. Data were collected at baseline and after the 3-month intervention. None of the PROMs were significantly different between the supplement and placebo groups. Disc degeneration according to Pfirrmann classifications remained stable during the 3-month intervention in both groups. Despite no significance regarding the distribution of Pfirrmann grade changes (improvement, no change, worsening; p = 0.259), in the supplement group, one patient achieved a three-grade improvement, and worsening of Pfirrmann grades were only detected in the placebo group (9.1%). Furthermore, in-depth evaluations of MRIs showed significantly higher 3D-measured volume changes (increase) in the supplement (+740.3 ± 796.1 mm3) compared to lower 3D-measured volume changes (decrease) in the placebo group (-417.2 ± 875.0 mm3; p < 0.001). In conclusion, this multi-nutrient supplement might not only stabilize the progression of lumbar osteochondrosis, but it might also potentially even increase IVD volumes as detected on MRIs.

Weightbearing Computed Tomography Can Accurately Detect Subtle Lisfranc Injury.

Early detection of Lisfranc injury is critical for improving clinical outcomes, but diagnosing subtle injury can be difficult. Weightbearing computed tomography (WBCT) allows evaluation of such injuries in 3 dimensions (3D) under physiologic load. This study aimed to assess the utility of 1-, 2-, and 3-dimensional measurements on WBCT to diagnose subtle injury in isolated ligamentous Lisfranc injuries. Ten cadaveric specimens underwent WBCT evaluation of the Lisfranc joint complex in the intact state and subsequently with sequential sectioning of the dorsal Lisfranc ligament and interosseous Lisfranc ligament (IOL) to create subtle Lisfranc injury, and finally after transectioning of plantar Lisfranc ligament (PLL) to create the injury conditions for complete ligamentous Lisfranc injury. Measurements under static vertical tibial load of 80 kg were performed on WBCT images including (1) Lisfranc joint (medial cuneiform-base of second metatarsal) volume, (2) Lisfranc joint area, (3) C1-C2 intercuneiform area, (4) C1-M2 distance, (5) C1-C2 distance, (6) M1-M2 intermetatarsal distance, (7) first tarsometatarsal (TMT1) alignment, (8) second tarsometatarsal (TMT2) alignment, (9) TMT1 dorsal step-off distance, and (10) TMT2 dorsal step-off distance. In the subtle Lisfranc injury state, Lisfranc joint volume and area, C1-M2 distance, and M1-M2 distance measurements on WBCT significantly increased, when compared with the intact state (P values .001 to .014). Additionally, Lisfranc joint volume and area, C1-M2 distance, M1-M2 distance, TMT2 alignment, and TMT2 dorsal step-off measurements were increased in the complete Lisfranc injury state. Of all measurements, C1-M2 distance had the largest area under the curve (AUC) of 0.96 (sensitivity = 90%; specificity = 90%), followed by Lisfranc volume (AUC = 0.90; sensitivity = 80%; specificity = 80%) and Lisfranc area (AUC = 0.89; sensitivity = 80%; specificity = 100%). In a cadaveric model we found that WBCT scan can increase the diagnostic accuracy for subtle Lisfranc injury. Among the measurements, C1-M2 distance exhibited the highest level of accuracy. The 2D joint area and 3D joint volume also proved to be accurate, with 3D volume measurements of the Lisfranc joint displaying the most significant absolute difference between the intact state and increasing severity of Lisfranc injury. These findings suggest that 2D joint area and 3D joint volume may have potential as supplementary measurements to more accurately diagnose subtle Lisfranc injuries. WBCT may help surgeons detect subtle Lisfranc injuries.

Characterization and quantification of in-vitro equine bone resorption in 3D using μCT and deep learning-aided feature segmentation

High cyclic strains induce formation of microcracks in bone, triggering targeted bone remodeling, which entails osteoclastic resorption. Racehorse bone is an ideal model for studying the effects of high-intensity loading, as it is subject to focal formation of microcracks and subsequent bone resorption. The volume of resorption in vitro is considered a direct indicator of osteoclast activity but indirect 2D measurements are used more often. Our objective was to develop an accurate, high-throughput method to quantify equine osteoclast resorption volume in μCT 3D images. Here, equine osteoclasts were cultured on equine bone slices and imaged with μCT pre- and postculture. Individual resorption events were then isolated and analyzed in 3D. Modal volume, maximum depth, and aspect ratio of resorption events were calculated. A convolutional neural network (CNN U-Net-like) was subsequently trained to identify resorption events on post-culture μCT images alone, without the need for pre-culture imaging, using archival bone slices with known resorption areas and paired CTX-I biomarker levels in culture media. 3D resorption volume measurements strongly correlated with both the CTX-I levels (p < 0.001) and area measurements (p < 0.001). Our 3D analysis shows that the shapes of resorption events form a continuous spectrum, rather than previously reported pit and trench categories. With more extensive resorption, shapes of increasing complexity appear, although simpler resorption cavity morphologies (small, rounded) remain most common, in acord with the left-hand limit paradigm. Finally, we show that 2D measurements of in vitro osteoclastic resorption are a robust and reliable proxy.

3D modeling and volume measurement of bulk grains stored in large warehouses using bi-temporal multi-site terrestrial laser scanning data

Terrestrial laser scanning (TLS) is a promising technology for quantity checking huge grain stocks with low cost, light workload and high efficiency. Existing applications of TLS in bulk grain measurement and quantification lack the ability to capture complete structural information of grain bulks and thus will result in large errors. In this paper, we propose a bi-temporal TLS scheme for fast 3D modeling and accurate volume measurement of bulk grains stored in large warehouses. The scheme uses bi-temporal multi-site TLS datasets acquired under both empty and full or high loading conditions to obtain complete surface information about grain bulk’s structure. In order for a grain bulk’s all external surfaces and the 3D volumetric model reconstructed therefrom to be automatically derived from the bi-temporal TLS dataset, several dedicated methods are developed for the scheme. A fully automated marker-free strategy exploring structurally semantic information inherent in the large grain storehouses is adopted to register multi-scan TLS point cloud data captured in large-scale granary scenes. Also, a local minima-based region growing technique is devised to extract underlying surfaces from a granary scene point cloud model. Experiments show that the proposed 3D modeling and volume measurement scheme can work effectively and quickly in TLS-based granary field applications and repeated test data demonstrate its correctness, repeatability and accuracy. Compared with the conventional manual measurement approach, the bi-temporal TLS scheme can not only achieve much higher measurement precision, but also greatly improve efficiency by significantly reducing cost, workload, and manpower. It has good potential for use in the area of nation-wide grain inventory inspection in China.

Prediction of Pharyngeal 3D Volume Using 2D Lateral Area Measurements During Swallowing.

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R2 = 0.816). Adding height and sex to the model increased R2 to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R2 = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior-posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

Diagnostic value of 3D volume measurement of central pulmonary artery based on CTPA images in the pulmonary hypertension

BackgroundThis retrospective study aims to evaluate the diagnostic value of volume measurement of central pulmonary arteries using computer tomography pulmonary angiography (CTPA) for predicting pulmonary hypertension (PH).MethodsA total of 59 patients in our hospital from November 2013 to April 2021 who underwent both right cardiac catheterization (RHC) and CTPA examination were included. Systolic pulmonary artery pressure (SPAP), mean PAP (mPAP), and diastolic PAP (DPAP) were acquired from RHC testing. Patients were divided into the non-PH group (18 cases) and the PH group (41 cases). The diameters of the main pulmonary artery (DMPA), right pulmonary artery (DRPA), and left pulmonary artery (DLPA) were measured manually. A 3D model software was used for the segmentation of central pulmonary arteries. The cross-sectional areas (AMPA, ARPA, ALPA) and the volumes (VMPA, VRPA, VLPA) were calculated. Measurements of the pulmonary arteries derived from CTPA images were compared between the two groups, and correlated with the parameters of RHC testing. ROC curves and decision curve analysis (DCA) were used to evaluate the benefit of the three-dimensional CTPA parameters for predicting PH. A multiple linear regression model with a forward-step approach was adopted to integrate all statistically significant CTPA parameters for PH prediction.ResultsAll parameters (DMPA, DRPA, DLPA, AMPA, ARPA, ALPA, VMPA, VRPA, and VLPA) of CTPA images exhibited significantly elevated in the PH group in contrast to the non-PH group (P < 0.05), and showed positive correlations with the parameters of RHC testing (mPAP, DPAP, SPAP) (r ranged 0.586~0.752 for MPA, 0.527~0.640 for RPA, and 0.302~0.495 for LPA, all with P < 0.05). For the MPA and RPA, 3D parameters showed higher correlation coefficients compared to their one-dimensional and two-dimensional counterparts. The ROC analysis indicated that the VMPA showed higher area under the curves (AUC) than the DMPA and AMPA without significance, and the VRPA showed higher AUC than the DRPA and ARPA significantly (DRPA vs. VRPA, Z = 2.029, P = 0.042; ARPA vs. VRPA, Z = 2.119, P = 0.034). The DCA demonstrated that the three-dimensional parameters could provide great net benefit for MPA and RPA. The predictive equations for mPAP, DPAP, and SPAP were formulated as [8.178 + 0.0006 * VMPA], [1.418 + 0.0005 * VMPA], and [-11.137 + 0.0006*VRPA + 1.259 * DMPA], respectively.ConclusionThe 3D volume measurement of the MPA and RPA based on CTPA images maybe more informative than the traditional diameter and cross-sectional area in predicting PH.

Improved early outcome prediction by MRI-based 3D tumor volume assessment in patients with CNS lymphomas.

Central nervous system lymphomas (CNSL) display remarkable clinical heterogeneity, yet accurate prediction of outcomes remains challenging. The IPCG criteria are widely used in routine practice for the assessment of treatment response. However, the value of the IPCG criteria for ultimate outcome prediction is largely unclear, mainly due to the uncertainty in delineating complete from partial responses during and after treatment. We explored various MRI features including semi-automated 3D tumor volume measurements at different disease milestones and their association with survival in 93 CNSL patients undergoing curative-intent treatment. At diagnosis, patients with more than 3 lymphoma lesions, periventricular involvement, and high 3D tumor volumes showed significantly unfavorable PFS and OS. At first interim MRI during treatment, the IPCG criteria failed to discriminate outcomes in responding patients. Therefore, we randomized these patients into training and validation cohorts to investigate whether 3D tumor volumetry could improve outcome prediction. We identified a 3D tumor volume reduction of ≥97% as the optimal threshold for risk stratification (=3D early response, 3D_ER). Applied to the validation cohort, patients achieving 3D_ER had significantly superior outcomes. In multivariate analyses, 3D_ER was independently prognostic of PFS and OS. Finally, we leveraged prognostic information from 3D MRI features and circulating biomarkers to build a composite metric that further improved outcome prediction in CNSL. We developed semi-automated 3D tumor volume measurements as strong and independent early predictors of clinical outcomes in CNSL patients. These radiologic features could help improve risk stratification and help guide future treatment approaches.

Three-Dimensional Volumetric Magnetic Resonance Imaging Analysis of Syringomyelia Evolution After Posterior Fossa Decompression for Chiari Malformation Type1

This study aims to introduce a method of three-dimensional (3D) volume magnetic resonance imaging (MRI) measurements to evaluate the evolution of syringomyelia (SM) in adults with Chiari malformation type 1 (CM-1) after posterior fossa decompression (PFD), to provide reproducible and accurate measurements. Radiologic and clinical data were obtained for 28 patients. MRI 3D syrinx volumes were evaluated by 2 observers using Philips Healthcare Tumor Tracking tool. The mean SM preoperative volume was 9.1 ± 15.3 cm3 versus 4.6 ± 8.7 cm3 postoperatively, corresponding to a volume variation reduced by -50% ± 33.4%. A total of 21 patients (75%) showed >25% reduction in SM volume postoperatively and 25 patients (89.2%) showed good to excellent postoperative clinical outcomes. Very high interobserver and intraobserver agreement was noted for 3D volumetric analysis with Cohen weighted κ coefficients (0.899-0.991). A negative correlation was found between the number of involved metameres and the postoperative SM volume reduction (Pearson correlation coefficient= 0.378; P= 0.047). Patients with better clinical outcomes had fewer syrinx septae (F= 8.830; P= 0.001). Similarly, better syrinx volume reduction was associated with fewer septae (F= 1.554; P= 0.233). A positive relationship was observed between clinical outcomes and postoperative syrinx volume reduction (F= 1.554; P= 0.233), with data similar to the reported literature. This study shows that 3D volume measurement of the syrinx cavity on MRI is a reproducible and accurate method to assess the postoperative evolution of SM in CM-1 after PFD. Most patients (75%) showed a reduction of SM volume, with a mean volume decrease of 50%. The reliability is yet to be validated in further larger studies.

Non-invasive pressure-volume analysis by 3-dimensional echocardiography: a novel method for left ventricular stroke work estimation

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Institute for Surgical Research, Oslo University Hospital. Introduction Left ventricular pressure-volume analysis is a powerful method to quantify left ventricular function. A major limitation of its clinical utility, however, is the need for invasive pressure and volume measurements. We hypothesized that accurate non-invasive left ventricular (LV) stroke work analysis is feasible by combining continuous 3-dimensional (3D) echocardiographic LV volume measurements with non-invasive LV pressure curve estimation. Purpose To investigate if LV stroke work can be estimated non-invasively by combining 3D echocardiographic volume measurements with non-invasive pressure curve estimation. Methods In 21 open-chest anesthetized canines, piezoelectric crystals were placed in the LV subendocardium for volume measurements and a micromanometer catheter was placed in the LV cavity for pressure measurements. Echocardiography was performed directly on the heart to acquire 3D LV volumes and timings of mitral and aortic valve events. The estimated LV pressure curve was obtained by adjusting the cardiac phases of an LV reference pressure curve to these valve events and adjusting its amplitude to measured peak LV pressure. Stroke work was calculated as the area under the pressure-volume curve from mitral valve closure to mitral valve opening. Non-invasively estimated and invasively measured stroke work were compared. Recordings were done during baseline, aortic constriction, dobutamine infusion and after induction of left bundle branch block by ablation. Results Panel A in the Figure illustrates non-invasive (left) and invasive (right) pressure-volume loops from a representative experiment. Baseline and the different interventions are colour-coded allowing visual comparison of the similar non-invasive and invasive stroke work. Panel B shows the pooled data from all experiments. There was a strong correlation (r=0.98, p&amp;lt;0.0001) and good agreement between the non-invasive and invasive stroke work. Furthermore, the non-invasive method captured similar changes in stroke work during interventions as compared to the invasive method (Panel C). Conclusions Non-invasive pressure-volume analysis by combining 3D echocardiography and estimated pressure for stroke work evaluation, is feasible and accurate.

Progestin-related breast volume changes in a woman with complete androgen insensitivity syndrome (CAIS).

A 31-year-old woman with complete androgen insensitivity syndrome (CAIS) experienced breast volume fluctuations during biphasic hormone replacement therapy consisting of estradiol and cyclical dydrogesterone, a progestin. 3D breast volume measurements showed a 100 cc volume (17%) difference between estradiol monotherapy and combined estradiol and dydrogesterone treatment. Progestogen-dependent breast volume changes have not been reported in the literature. Our findings suggest a correlation between progestogen use and breast volume. Due to the rapid cyclical changes, we hypothesize that the effect is caused by fluid retention. There is limited reports available on the effects of progesterone on breast development and volume. 3D imaging provides an easy-to-use method to quantify breast volume. The patient in our case description clearly showed that cyclic progesterone use might induce substantial cyclic changes in breast volume. In women with complete androgen insensitivity syndrome (CAIS), monotherapy with estrogen or continuous supplementation of progesterone might be preferable over cyclic progesterone use.

The Significant Role of Tumor Volume on the Surgical Approach Choice, Surgical Complexity, and Postoperative Complications in Renal Cell Carcinoma With Venous Tumor Thrombus From a Large Chinese Center Experience.

ObjectiveTo explore the role of tumor volume (TV) on surgical approach choice, surgical complexity, and postoperative complications in patients with renal cell carcinoma (RCC) and inferior vena cava tumor thrombus.MethodFrom January 2014 to January 2020, we retrospectively analyzed the clinical data of 132 patients who underwent radical nephrectomy with inferior vena cava thrombectomy (RN-IVCT). Primary renal tumor volume (PRTV), renal vein tumor thrombus volume (RVTTV), inferior vena cava tumor thrombus volume (IVCTTV), and total tumor thrombus volume (TTTV) were measured with the help of an internationally recognized 3D volume measurement software. The patients were divided into three groups according to the tumor volume within the inferior vena cava (IVC). Group 1 included 48 patients with IVCTTV between 0 and 15 cm3 (36.6%), group 2 included 38 patients with IVCTTV between 16 and 30 cm3 (28%), and group 3 included 46 patients with IVCTTV above 30 cm3 (35%). The three IVCTTV groups, as well as four different volume groups, were compared in terms of surgical approach choice, surgical complexity, and postoperative complications. One-way ANOVA and a non-parametric test were used to compare the clinicopathological characteristics and distribution differences between the three groups.ResultThis study found significant differences among the three groups in the proportion of open surgery (P < 0.001), operation time (P < 0.044), intraoperative bleeding (P < 0.001), and postoperative complications (P < 0.001). When the four different volumes were compared, we found that for higher volumes IVCTTV and TTTV, open surgery is used more often compared with laparoscopic surgery (P < 0.001). In addition, with the increase in renal vein tumor thrombus volume, inferior vena cava tumor thrombus volume, and total tumor thrombus volume, the operation time also increased. Finally, with the increase in tumor thrombus volume and total tumor thrombus volume, the amount of intraoperative bleeding increased.ConclusionWith the increase in tumor volume, the proportion of open surgery and the incidence of postoperative complications increased. In addition, larger tumor volume prolongs operation time, increases intraoperative blood loss, and makes the surgery more complicated.

Reliability and agreement of lumbar multifidus volume and fat fraction quantification using magnetic resonance imaging

IntroductionMagnetic resonance imaging (MRI) is the standard to quantify size and structure of lumbar muscles. Three-dimensional volumetric measures are expected to be more closely related to muscle function than two-dimensional measures such as cross-sectional area. Reliability and agreement of a standardized method should be established to enable the use of MRI to assess lumbar muscle characteristics. ObjectivesThis study investigates the intra- and inter-processor reliability for the quantification of (1) muscle volume and (2) fat fraction based on chemical shift MRI images using axial 3D-volume measurements of the lumbar multifidus in patients with low back pain. MethodsTwo processors manually segmented the lumbar multifidus on the MRI scans of 18 patients with low back pain using Mevislab software following a well-defined method. Fat fraction of the segmented volume was calculated. Reliability and agreement were determined using intra-class correlation coefficients (ICC), Bland-Altman plots and calculation of the standard error of measurement (SEM) and minimal detectable change (MDC). ResultsExcellent ICCs were found for both intra-processor and inter-processor analysis of lumbar multifidus volume measurement, with slightly better results for the intra-processor reliability. The SEMs for volume were lower than 4.1 cm³. Excellent reliability and agreement were also found for fat fraction measures, with ICCs of 0.985–0.998 and SEMs below 0.946%. ConclusionThe proposed method to quantify muscle volume and fat fraction of the lumbar multifidus on MRI was highly reliable, and can be used in further research on lumbar multifidus structure.

Volume Measurements on Weightbearing Computed Tomography Can Detect Subtle Syndesmotic Instability

Category:Ankle; TraumaIntroduction/Purpose:The ability to compare the ankle joints bilaterally in a 3D manner under physiologic weight provided by weight-bearing CT has led to a more accurate diagnostic method. While weight-bearing computed tomography (WBCT) allows 3D visualization of the distal syndesmosis, image interpretation has largely relied on 1D distance and, more recently, 2D area measurements. This study aimed to: 1) determine the sensitivity and specificity of 2D area and 3D volume WBCT measurements towards detecting subtle syndesmotic instability, 2) evaluate whether the patterns of changes in the 3D shape of the syndesmosis can be attributed to the type of ligament injury.Methods:A total of 24 patients with unilateral subtle syndesmotic instability and 24 individuals with uninjured ankles (controls) with bilateral ankle WBCT were assessed retrospectively. First, 2D areas at 0, 1, 3, 5,10 cm, and 3D volumes at 1, 3, 5, and 10cm above the tibial plafond were measured bilaterally. Secondly, given the volume measurement at the level of 5 cm proximal to the platform as the most sensitive and specific method introduced in this study, the 3D model of the distal tibiofibular space was created based on WBCT in a subset of 8 patients out of 24 in whom the type of ligament injury was recognized via MRI. The 3D model of the injured side was superimposed on the uninjured contralateral side to visualize the pattern of changes in different planes. P<0.05 was considered statistically significant.Results:No specific pattern was observed in 2D and 3D models of the syndesmotic space which can be attributed to a specific ligamentous tear. However, in patients with IOL rupture, the volume increased by >=39% at 5 cm height while without IOL injury the volume increased up to 26% (figure 1). The percentage of changes in 2D areas and 3D volumes showed significant differences in areas at 0cm (19.2%; p=0.004), 1cm (24.1%; p=0.002), 3cm (27.3%; p=0.003), 5cm (28%; p=0.002), and 10cm (29.3%; p=0.003) as well as volumes at 1cm (31.2%; p=0.003), 3cm (26.5%; p=0.001), 5cm (25.4%; p<0.001), and 10cm (24.7%; p=0.004) proximal to tibial plafond. Volume up to 5cm showed the lowest p-value, higher sensitivity (95.8%, 95%CI:87.8-100), and specificity (83.3%, 95% CI:68.4-98.2) for detection of syndesmotic instability.Conclusion:We suggest 3D volume measurements, best measured up to 5cm proximal to the plafond, as a promising means of diagnosing syndesmotic instability, particularly for subtle cases that are hard to detect.

Deep Learning Improves the Accuracy of Weightbearing CT Scan in Detecting Subtle Syndesmotic Instability

Category:Ankle; TraumaIntroduction/Purpose:Weightbearing CT (WBCT) scan provides an ability to compare the ankle joints bilaterally in a 3D manner under physiologic load. According to our recent investigations, 3D volume measurement of the syndesmosis, if measured up to 5cm proximal to the tibial plafond, can detect the instability with an accuracy of 90%, sensitivity of 95.8%, and specificity of 83.3%. However, these values can differ based on the knowledge and experience of the human interpreter. Deep learning, as a subset of machine learning, has shown promising potentials in processing and analyzing images and detecting abnormalities within the images using deep convolutional neural networks (DCNN). Herein, we aimed to assess the accuracy, sensitivity, and specificity of 3D volume WBCT evaluation using DCNN algorithms in patients with subtle syndesmotic instability.Methods:In this study 140 bilateral ankle WBCT scans of patients with subtle syndesmotic instability who were diagnosed intraoperatively were allocated to the patient group. The control group comprised 140 bilateral ankle WBCT images of healthy individuals. We utilized inception V3 model for our DCNN. Data augmentation and transfer learning were used; however, the images were not preprocessed in terms of change in size and resolution. The data were divided as 80:10:10 for training, validation, and test subsets, respectively. The outcome of the study was expressed as sensitivity, specificity, F-score, and the area under the curve (AUC).Results:The performance of our DCNN algorithm showed a sensitivity of 99.41%, specificity of 99.34%, F-score of 99.37%, and 99.99% AUC (Figure 1). The change in loss value of the train data was plateaued after 40 iterations. Axial images were the most appropriate images that were used by the algorithm to detect the instability.Conclusion:In this study we observed that using DCNN in the process of WBCT image interpretation for diagnosis of syndesmotic instability, particularly in subtle cases, makes this modality almost perfect with a very small chance of missing a case. Training a DCNN using a greater number of inputs is still recommended to improve the validity and reliability of this method. Providing a heat map will also help clinicians discover the process of decision-making by these algorithms as DCNNs are sometimes called 'black box'.

WBCT Can Effectively Diagnose Syndesmotic Instability Among Patients with Weber B Ankle Fractures

Category:Ankle; TraumaIntroduction/Purpose:Diagnosing and treating syndesmotic instability that occurs in some Weber B ankle fractures is essential to restore normal ankle joint kinematics and optimize clinical outcomes however subtle instability can be difficult to identify.WBCT evaluates the syndesmotic joint under physiologic load. We compared the diagnostic sensitivities of one-dimensional (1D) distance, two-dimensional (2D) area, and three-dimensional (3D) volumetric measurement of the injured syndesmotic joint on WBCT, in patients with unilateral Weber B ankle fractures with surgically-confirmed syndesmotic instability, to the contralateral uninjured side.Methods:Patients with unilateral surgically confirmed syndesmotic instability accompanying a Weber B type lateral malleolar ankle fracture (n = 23) who underwent preoperative bilateral foot and ankle WBCT were included. A separate group of patients with unilateral Weber B ankle fractures without syndesmotic instability and who underwent bilateral WBCT were included as a control group (n = 18). With the uninjured side serving as an internal control, measurements on bilateral WBCT images included: 1) syndesmotic area, 2) tibiofibular distance measured at the anterior, middle, and posterior aspect of the distal tibiofibular articulation, 3) fibular rotation, 4) distance from fibular tip to plafond, 4) fibular fracture displacement and 5) medial clear space distance. In addition, 3D volumetric measurements: 1) syndesmotic joint volume from the tibial plafond extending to 3cm and 5cm proximally, respectively 2) medial clear space volume, and 3) lateral clear space volume were calculated, and their sensitivities were compared to the aforementioned measurements.Results:Among patients with unilateral syndesmotic instability with Weber B ankle fractures, all WBCT measurements except medial clear space distance, syndesmotic area, and anterior and posterior tibiofibular distance were significantly greater on the injured compared to the uninjured side (p-values ranging from <0.001 to 0.004). Of these measurements, 3D syndesmosis volumetric measurements spanning from the tibial plafond to a level 3cm and 5cm proximally had the highest relative volumetric ratio between the injured and uninjured side, suggesting high sensitivity to distinguish between stable and unstable syndesmotic injuries (p -values ranging from 0.001 to 0.036). In the control group without syndesmotic instability, all evaluated WBCT parameters except for MCS volume, and distal fibular tip to tibial plafond showed no significant side-to-side difference.Conclusion:Bilateral WBCT can effectively diagnose syndesmotic instability among patients with Weber B ankle fractures. While middle incisura distance, fibular rotation, and 3D volumetric measurements can all be used to identify such instability, 3D syndesmotic volume measurements are the most sensitive and thus strongly recommended for future application in scenarios of clinical dilemma of syndesmotic injury-particularly when injuries are subtle. When performing these 3D volume measurements, it appears that syndesmosis volume extending from the tibial plafond to a height of 5cm proximally is best suited to evaluate such instability given the larger absolute side to side difference of 3.5 cm3.

Automated Volume Measurement of the Syndesmosis Using 3D Weightbearing CT

Category:Ankle; Trauma; OtherIntroduction/Purpose:Recent studies have shown that weight-bearing computed tomography (WBCT) that allows 3D volume measurement of the distal syndesmosis while under physiologic load brings about a higher accuracy in detection of syndesmotic instability, especially if subtle. Since the volume measurement method is complex, time-consuming, and has a noticeable interobserver bias, most clinicians might not still be interested in utilizing it in practice. Automatization of this measurement using computer-assisted methods will not only reduce the interobserver bias but also will be faster and more applicable in practice. This study aimed to develop an automated 3D syndesmosis volume measurement tool using image processing methods and compare the speed and the interobserver bias with human interpreters.Methods:We included 30 patients with subtle syndesmotic instability who had undergone WBCT and were diagnosed intraoperatively. Thirty individuals with otherwise healthy ankles who had WBCT images were allocated to the control group. The volume measurement up to 5cm proximal to the tibial plafond was considered as the most sensitive and specific method to assess syndesmotic stability based on the literature. An algorithm was developed using MATLAB software that could recognize and calculate the syndesmotic volume using WBCT images. The volume measurement method was used by two orthopaedic surgeons for the same population. The time spent by each surgeon and the algorithm was measured. Finally, the values were compared using the t-test; the interobserver correlation coefficient (ICC) was also calculated. P<0.05 was considered statistically significant.Results:The percentage of changes in 3D volume showed a significant difference at 5cm (25.4%; p<0.001), proximal to the tibial plafond. Based on our clinical study, the volume measurement up to 5cm showed a sensitivity of 95.8%, 95%CI:87.8-100, and specificity of 83.3%, 95% CI:68.4-98.2 for detection of syndesmotic instability. The ICC between the clinicians was 75% while using the automated measurement algorithm showed an ICC of 97%. The mean time spent by the clinicians was 268.4+-56.4 and by the algorithm was 2.9+-0.3 seconds (p<0.001, Figure 1).Conclusion:Given the fact that 3D volume measurement of the syndesmosis using WBCT is still a complex technique for most clinicians while it is one of the most accurate diagnostic methods based on recent literature, developing a faster and more accurate method for 3D volume measurement of the syndesmosis leads to a more reliable and easier to use the technique to be used in practice.

Open osteology: Medical imaging databases as skeletal collections

• Medical imaging datasets can be used as skeletal reference collections • Computed tomography data from TCIA can be accessed via 3D Slicer • Many tools in 3D Slicer support skeletal analyses and dissemination products • 3D bone models can be used for education, research, training, web-based reference • Bone modeling in 3D Slicer will support common workflows and shareable datasets The increasing availability of de-identified medical image databases, especially of computed tomography (CT) scans, presents an opportunity for “open osteology,” or the establishment of new skeletal reference collections. The number of free and/or open-source software packages for generating three-dimensional (3D) CT models, such as 3D Slicer, reduces financial obstacles to working with CT data and encourages the development of common workflows and datasets. The direct link to the Cancer Imaging Archive from 3D Slicer facilitates access to medical imaging datasets to support education and research with virtual skeletal data. Generation of 3D models enables computational methods for skeletal analyses and can also lead to the generation of virtual libraries representing large amounts of human skeletal variation. 3D printing of 3D CT models can supplement physical skeletal collections for the classroom and research beyond the standard commercially available specimens. Web-based technologies support 3D model and CT volume visualization, interaction, and measurement, increasing opportunities for dissemination and collaboration as well as the possible integration of 3D data as references for skeletal analysis tools. Increasing awareness and usage of pre-existing free and open-source resources applicable to forensic anthropology will facilitate method/workflow development, validation, and eventually standardization. This presentation will discuss online sources of skeletal data, outline methods for processing CT scans with free software into 3D digital models and discuss web-based technologies and repositories that allow interaction with 3D skeletal models. The demonstration of these methods will contribute to discussions on the expansion of virtual anthropology and open osteology.

Semi-Automatic Volumetric and Standard Three-Dimensional Measurements for Primary Tumor Evaluation and Response to Treatment Assessment in Pediatric Rhabdomyosarcoma.

Current prognostic classification of rhabdomyosarcoma in children requires precise measurements of the tumor. The purpose of the study was to compare the standard three-dimensional (3D) measurements with semi-automatic tumor volume measurement method concerning assessment of the primary tumor size and the degree of response to treatment for rhabdomyosarcoma in children. Magnetic Resonance Imaging data on 31 children with treated rhabdomyosarcoma based on the Cooperative Weichteilsarkom Studiengruppe (CWS) guidance was evaluated. Tumor sizes were measured by two methods: 3D standard measurements and semi-automatic tumor volume measurement (VOI) at diagnosis, and after 9 and 17/18 weeks of the induction chemotherapy. Response to treatment and prediction values were assessed. The tumor volume medians calculated using VOI were significantly higher in comparison with those calculated using the 3D method both during the diagnosis as well as after 9 weeks of the chemotherapy and during the 17–18th week of the treatment. The volume measurements based on the generalized estimating equations on the VOI method were significantly better than the 3D method (p = 0.037). The volumetric measurements alone can hardly be considered an unequivocal marker used to make decisions on modification of the therapy in patients with rhabdomyosarcoma.