Volumetric Comparison Research Articles

Accuracy of deep learning-based upper airway segmentation

IntroductionIn orthodontic treatments, accurately assessing the upper airway volume and morphology is essential for proper diagnosis and planning. Cone beam computed tomography (CBCT) is used for assessing upper airway volume through manual, semi-automatic, and automatic airway segmentation methods. This study evaluates upper airway segmentation accuracy by comparing the results of an automatic model and a semi-automatic method against the gold standard manual method. Materials and methodsAn automatic segmentation model was trained using the MONAI Label framework to segment the upper airway from CBCT images. An open-source program, ITK-SNAP, was used for semi-automatic segmentation. The accuracy of both methods was evaluated against manual segmentations. Evaluation metrics included Dice Similarity Coefficient (DSC), Precision, Recall, 95% Hausdorff Distance (HD), and volumetric differences. ResultsThe automatic segmentation group averaged a DSC score of 0.915±0.041, while the semi-automatic group scored 0.940±0.021, indicating clinically acceptable accuracy for both methods. Analysis of the 95% HD revealed that semi-automatic segmentation (0.997±0.585) was more accurate and closer to manual segmentation than automatic segmentation (1.447±0.674). Volumetric comparisons revealed no statistically significant differences between automatic and manual segmentation for total, oropharyngeal, and velopharyngeal airway volumes. Similarly, no significant differences were noted between the semi-automatic and manual methods across these regions. ConclusionIt has been observed that both automatic and semi-automatic methods, which utilise open-source software, align effectively with manual segmentation. Implementing these methods can aid in decision-making by allowing faster and easier upper airway segmentation with comparable accuracy in orthodontic practice.

A Comparison of Pre- and Post-Treatment Cranial MRI Characteristics in Patients with Pediatric Epilepsy Receiving Levetiracetam.

Background and Objectives: This study was performed for the purpose of assessing whether antiepileptic levetiracetam treatment produces a change in brain volumes in children with epilepsy. To that end, we compared the volumes of the basal ganglia (caudate nucleus, putamen, globus, hip-pocampus, and thalamus) at magnetic resonance imaging (MRI) before and after treatment (months 18-24) in pediatric epilepsy patients using levetiracetam. Materials and Methods: This retrospective study involved a volumetric comparison of patients presenting to the Balikesir University Medical Faculty pediatric neurology clinic between 01.08.2019 and 01.11.2023 and diagnosed with epilepsy, and who underwent cranial MRI before and 18-24 months after treatment at the radiology department. The demographic and clinical characteristics (age, sex, family history of epilepsy, type of epilepsy, and EEG features (normal, abnormal, epileptiform)) of the patients included in the study were recorded. Results: The comparison of basal ganglia volumes at cranial MRI before and at months 18-24 of treatment revealed significant differences in the left caudate nucleus, right putamen, left putamen, left globus pallidus, right thalamus, left thalamus, and right hippocampal regions. Conclusions: In conclusion, differing findings are encountered at cranial imaging in patients with epilepsy, depending on the seizure frequency, activity, and the type of antiepileptic drugs used. This study compared basal ganglia volumes on cranial MRIs taken before and 18-24 months after treatment in pediatric epilepsy patients using levetiracetam. A significant increase was observed in the volumes of basal ganglia (caudate nucleus, putamen, globus pallidus, hippocampus, and thalamus) on the MRIs of pediatric epilepsy patients using levetiracetam.

Volumetric analysis of acute uncomplicated type B aortic dissection using an automated deep learning aortic zone segmentation model

BackgroundMachine learning techniques have shown excellent performance in three-dimensional medical image analysis, but have not been applied to acute uncomplicated type B aortic dissection (auTBAD) using Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS)-defined aortic zones. The purpose of this study was to establish a trained, automatic machine learning aortic zone segmentation model to facilitate performance of an aortic zone volumetric comparison between patients with auTBAD based on the rate of aortic growth. MethodsPatients with auTBAD and serial imaging were identified. For each patient, imaging characteristics from two computed tomography (CT) scans were analyzed: (1) the baseline CT angiography (CTA) at the index admission and (2) either the most recent surveillance CTA or the most recent CTA before an aortic intervention. Patients were stratified into two comparative groups based on aortic growth: rapid growth (diameter increase of ≥5 mm/year) and no or slow growth (diameter increase of <5 mm/year). Deidentified images were imported into an open source software package for medical image analysis and images were annotated based on SVS/STS criteria for aortic zones. Our model was trained using four-fold cross-validation. The segmentation output was used to calculate aortic zone volumes from each imaging study. ResultsOf 59 patients identified for inclusion, rapid growth was observed in 33 patients (56%) and no or slow growth was observed in 26 patients (44%). There were no differences in baseline demographics, comorbidities, admission mean arterial pressure, number of discharge antihypertensives, or high-risk imaging characteristics between groups (P > .05 for all). Median duration between baseline and interval CT was 1.07 years (interquartile range [IQR], 0.38-2.57). Postdischarge aortic intervention was performed in 13 patients (22%) at a mean of 1.5 ± 1.2 years, with no difference between the groups (P > .05). Among all patients, the largest relative percent increases in zone volumes over time were found in zone 4 (13.9%; IQR, −6.82 to 35.1) and zone 5 (13.4%; IQR, −7.78 to 37.9). There were no differences in baseline zone volumes between groups (P > .05 for all). The average Dice coefficient, a performance measure of the model output, was 0.73. Performance was best in zone 5 (0.84) and zone 9 (0.91). ConclusionsWe describe an automatic deep learning segmentation model incorporating SVS-defined aortic zones. The open source, trained model demonstrates concordance to the manually segmented aortas with the strongest performance in zones 5 and 9, providing a framework for further clinical applications. In our limited sample, there were no differences in baseline aortic zone volumes between patients with rapid growth and patients with no or slow growth.

Exploring volumetric abnormalities in subcortical L-HPA axis structures in pediatric generalized anxiety disorder

Background Pediatric generalized anxiety disorder (GAD) is debilitating and increasingly prevalent, yet its etiology remains unclear. Some believe the disorder to be propagated by chronic dysregulation of the limbic-hypothalamic-pituitary-adrenal (L-HPA) axis, but morphometric studies of implicated subcortical areas have been largely inconclusive. Recognizing that certain subcortical subdivisions are more directly involved in L-HPA axis functioning, this study aims to detect specific abnormalities in these critical areas. Methods Thirty-eight MRI scans of preschool children with (n = 15) and without (n = 23) GAD underwent segmentation and between-group volumetric comparisons of the basolateral amygdala (BLA), ventral hippocampal subiculum (vSC), and mediodorsal medial magnocellular (MDm) area of the thalamus. Results Children with GAD displayed significantly larger vSC compared to healthy peers, F(1, 31) = 6.50, pFDR = .048. On average, children with GAD presented with larger BLA and MDm, Fs(1, 31) ≥ 4.86, ps FDR ≤ .054. Exploratory analyses revealed right-hemispheric lateralization of all measures, most notably the MDm, F(1, 31) = 8.13, pFDR = .024, the size of which scaled with symptom severity, r = .83, pFDR = .033. Conclusion The BLA, vSC, and MDm are believed to be involved in the regulation of anxiety and stress, both individually and collectively through the excitation and inhibition of the L-HPA axis. All were found to be enlarged in children with GAD, perhaps reflecting hypertrophy related to hyperexcitability, or early neuronal overgrowth. Longitudinal studies should investigate the relationship between these early morphological differences and the long-term subcortical atrophy previously observed.

En Face and Volumetric Comparison of Hypertransmission Defects Evaluated by Cirrus and Spectralis Optical Coherence Tomography

PurposeTo evaluate and compare en face and 3-dimensional (D) properties of hypertransmission defects (HTDs) between different optical coherence tomography (OCT) devices using OCT volumes and reconstructed en face images. SettingsComparative diagnostic evaluation study. MethodsThirty eyes with dry age-related macular degeneration (AMD) that underwent dense OCT macular volume scans with both the Spectralis (97 B-scans/volume; 2,910 B-scans in total) and Cirrus OCT (128 B-scans/volume; 3,840 B-scans in total) from AMISH EYE STUDY cohort were included in this analysis. HTD regions were labeled on each B-scan and reconstructed into en face and 3-D volume images. Properties of HTD volume were compared between the two devices. ResultsQualitative score of en face images for HTD was higher for the Cirrus compared to the Spectralis (P < 0.01). The quality of Spectralis en face images improved after preprocessing and reconstruction. The 2-D HTD area on en face obtained from 2-D projections of 3-D volume did not differ between devices (P = 0.478; ICC 0.998; Jaccard index 0.721 ± 0.086). There was no difference in the number, volume, PALs, and surface areas of HTDs between devices in the volumetric analysis (all P ≥ 0.090). The signal intensity of HTD normalized by the mean choroidal signal intensity did not differ between devices (P = 0.861). ConclusionsThe visualization of HTD on en face images from Spectralis OCT could be enhanced through image processing. The equivalence in 3-D HTD parameters between the two devices suggests interchangeability for assessing these lesions in AMD.

Volumetric comparison of mandibular condyles and mandibles in the different skeletal classes in the Saudi population.

Assessing the relationship between the condyle and mandible volume and the various skeletal classes is essential in orthodontic diagnosis. The current study evaluated this relationship using volumetric cone-beam computed tomography (CBCT), cephalometric methods, and the correlations between them. The study examined 37 full-head CBCTs (74 condyles) from adults in the Saudi population. The condyle and mandible were separated from within the CBCT images. The volume of each segment was compared to measurements from multiple cephalometric analyses. The combined total condylar volume has a moderate correlation with the maxillomandibular differential in each of the genders and in the total sample. Mandibular volume has a significant correlation with the Wits appraisal (sagittal classification) in males. It was also significantly correlated with the vertical classification using gonial angles in females and in the total sample. The relationship between mandible and condyle volume and cephalometric measurements is both dimensional and within the maxillomandibular complex rather than positional or related to the cranial base. Also, the correlation between the condylar and mandibular volumes and the sagittal and vertical dimensions in the orthodontic skeletal classes provides better insight into the mandibular complex.

Syn‐rift tectono‐stratigraphic development of the Thebe‐0 fault system, Exmouth Plateau, offshore NW Australia: The role of fault‐scarp degradation

AbstractThe syn‐rift architecture of extensional basins records deposition from and interactions between footwall‐, hangingwall‐, and axially‐derived systems. However, the exact controls on their relative contributions and the overall variable depositional architecture, and how their sediment volume varies through time, remains understudied. We undertook a quantitative approach to determine temporal and spatial changes in the contribution of fault‐scarp degradation to the syn‐rift tectono‐stratigraphic development of the Thebe‐0 fault system on the Exmouth Plateau (NW Shelf, offshore Australia), using high‐quality 3D seismic reflection and boreholes data. The magnitude of footwall erosion was measured in terms of vertical (VE) and headward (HE) erosion by calculating the volume of eroded material along the footwall scarp. A detailed seismic‐stratigraphic and facies analysis allowed us to constrain the architectural variability of the hangingwall depositional systems and the types of resulting deposits (i.e., fault‐controlled base‐of‐scarp, settling from suspension, and hangingwall‐derived). After addressing the syn‐rift tectono‐stratigraphic framework, we suggest that periods of significant erosion along the Thebe‐0 fault scarp are related to the accumulation of fault‐controlled base‐of‐scarp deposits characterised by comprising a lower wedge with chaotic to low‐continuity reflections. Footwall‐derived deposits characterised by an upward decrease in stratigraphic dip are interpreted as related to periods of reduced fault activity and sustained sediment delivery sourced from the footwall scarp and systems beyond it (e.g., antecedent systems). We then analysed the tectono‐stratigraphic framework and the volumetric comparison between material eroded from the fault‐scarp and accumulated in the basin, aiming to estimate the contribution of fault‐scarp degradation to the hangingwall syn‐rift fill. Our results suggest periods of enhanced fault activity control fault‐scarp degradation variability through time, and we agree with that described by previous researchers—fault throw variability along‐strike regulates the variability in the magnitude of erosion. However, we propose that fault‐scarp degradation timing and its spatial variability are also influenced by the interaction and linkage with adjacent normal faults and by sea level variations. Lastly, we determine broader similarities and differences with a system located in the same fault array (i.e., Thebe‐2 fault system), aiming to give insights into the tectono‐stratigraphic evolution of a broader area and the spatial variability in fault‐scarp degradation.

Evaluation Coastal Volume Changes with UAV Photogrammetry: An Example in West Coast Malaysia

Variations of beach volume changes have been put into place at the coastline to measure the changes in volume and analyse beach response using geometric and volumetric comparison of beach profile sets. This study examined the volume change of a beach in an eroded location in Batu Pahat. As Pantai Punggur was identified as an eroding area, it was chosen as the research area where identifying changes to the beach's volume is necessary to evaluate changes to the condition of the beach. There is a rather strong demand for both technologies and research methods since technology tends to advance quickly. Therefore, in order to satisfy demand, the process of identifying the volumetric of the shoreline area was carried out using an unmanned aerial vehicle with the assistance of Pix4D Mapper and Global Mapper as a medium to study the changes in beach volume. Pix4D Mapper was used to process the beach volume changes and to analyze the aerial image, while the Global Mapper software conducted an analysis of beach volume changes. This study demonstrates that there is a noticeable shift in the volume of the beach within a month. Overall, the data provided demonstrates that Zones A and E are more vulnerable to erosion than the other zones.

Twenty Years of Managed Epilepsy for a Stranded Male Guadalupe Fur Seal (Arctocephalus townsendi) Secondary to Suspect Domoic Acid Toxicosis

Many wild otariids (sea lions and fur seals) strand along the California coast annually with seizures following presumed exposure to harmful algal blooms (HABs). This is a long-term case study of a stranded subadult male Guadalupe fur seal (Arctocephalus townsendi) that stranded in 2001 and within days after admission began demonstrating seizure activity. The epilepsy was stabilized with antiepileptic drug (AED) therapy and advanced imaging was performed. Magnetic resonance (MR) scans showed signs of encephalopathy consistent with domoic acid (DA) toxicosis. This fur seal was deemed “non-releasable” and over the following 19 years, he received supportive veterinary care and AED treatment at a permitted facility. In the summer of 2020, the fur seal showed progressive behavioral and functional deterioration whereupon humane euthanasia was performed. Post-mortem MR and diffusion tensor images (DTI) were acquired. A volumetric comparison with historic scans showed evidence of severe progressive unilateral right hippocampal atrophy. Histopathology confirmed severe chronic right and mild left hippocampal atrophy. The progressive degenerative brain changes demonstrate how adaptive brain function can be with neuronal atrophy secondary to DA exposure. This case highlights some considerations and decision-making processes needed for the rehabilitation and placement of wild stranded otariids with acquired epilepsy secondary to DA toxicity.

Neuroanatomy of a sex changing fish: the New Zealand spotty wrasse (Notolabrus celidotus) brain atlas

ABSTRACT For most vertebrates, sexual fate is genetically determined and remains fixed throughout life. However, for some teleost fishes sex is more plastic. Significant progress has been made in characterising the cellular and molecular processes that underpin gonadal sex change. The brain-mediated mechanisms that underlie and initiate this transformation, however, remain poorly understood. One reason for this is the current lack of a neuroanatomical reference work for sex changing fishes. Here, we present a brain atlas for the New Zealand (NZ) spotty wrasse (Notolabrus celidotus), developed from 10 wild caught specimens (2 male and 8 female). From each fish, coronal cryosections were collected and stained with cresyl violet solution. Photomicrographs were taken of each section using an inverted bright field microscope and 3D reconstructions were rendered of each brain for annotation and volumetric comparison of specific brain regions. The brain atlas describes the general features of the NZ spotty wrasse brain as well as its specificities. This atlas provides the necessary foundation for further investigation of the brain mechanisms driving protogyny in this species.

Volumetric Comparison Between CT Scans and Smartphone-Based Photogrammetry in Patients Undergoing Chin Augmentation With Autologous Fat Graft.

The most accurate methods for assessing fat grafted volume, such as computed tomography (CT) scan and magnetic resonance imaging, use 3-dimensional (3D) evaluation of the recipient area. Currently, other measurement techniques such as photogrammetry (compilation of photos) are employed. The aim of the present study was to compare 3D images obtained by CT scan with those obtained by photogrammetry in patients undergoing autogenous fat grafting to the chin. A prospective longitudinal study was undertaken to assess patients undergoing autologous fat grafting to the chin, capturing preoperative and postoperative (6 months) images with CT scan and photogrammetry. Captured images were submitted to 3D reconstruction with Blender image software. A total of 40 patients were submitted to surgery. Seventy-five percent were female. Median age and BMI were 26.5 years and 23.6 kg/m2, respectively. Median volume of fat grafted was 10 mL (interquartile range 8-12.25 mL). Results showed that the median preoperative volume measured by CT scan was larger than the photogrammetry measurement (12.48 mL vs 12.01 mL, respectively, P < .001). Likewise, a larger volume was measured by CT scan than by photogrammetry (15.54 mL vs 14.94 mL respectively, P < .001) 6 months postoperatively. However, there was no difference between CT scan and photogrammetry measurements of the change in volume from preoperatively to postoperatively (P = .89). There was no agreement between fat graft volume measurements obtained by 3D photogrammetry and CT scan techniques with regard to absolute values of fat graft volume measurements, however no difference was found between the 2 methods when comparing preoperative with postoperative fat graft volume variation.

Dosimetric Study Comparing 3D Conformal Radiotherapy (3D-CRT), Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) in Hypofractionated One-Week Radiotherapy Regimen in Breast Cancer.

Introduction Recently, the one-week hypofractionated radiotherapy regimen (26 Gy in 5 fractions) for adjuvant breast radiotherapy has been shown to be non-inferior to other hypofractionated regimens (15-16 fractions). The aim of the present dosimetric study is to compare Intensity Modulated Radiotherapy (IMRT), Volumetric Modulated Arc Therapy (VMAT) and 3D Conformal Radiotherapy (3D-CRT) for a one-week hypofractionated radiotherapy regimen (26 Gy in 5 fractions) for adjuvant breast radiotherapy. Methods A total of 30 patients with histologically proven invasive carcinoma of the breast after breast conservation surgery (BCS) or modified radical mastectomy (MRM) were considered for in silico planning study. The dose prescription used was 26 Gy in 5 fractionsas used in the FAST Forward protocol. Targets were contoured according to standard guidelines. The heart, ipsilateral lung, and contralateral breast were contoured as organs at risk. Results Planning Target Volume (PTV) coverage:For IMRT, VMAT and 3D-CRT, respectively, the volumes that received at least 95% of the prescription dose (V95) were 95.7 ± 2.12, 92.47 ± 3.83, 90.87 ± 5.13; mean PTV doses (Dmean) were 26.1 ± 0.6, 25.7 ± 0.7, and 28 ± 4.39 (3D-CRT has higher Dmean compared to other techniques). Maximum PTV doses (Dmax) were 28.23 ± 0.72, 28.73 ± 0.64, and 29.8 ± 1.03. IMRT had a better V95 coverage and conformity index. Organs At Risk (OARs):The volumes that received at least 25% of the prescription dose (V25) of the heart were 3.41 ± 4.7, 1.8 ± 2.02 and 4.3 ± 6.98 in IMRT, VMAT and 3D-CRT, respectively. The volumetric (V25) comparison of heart dose in left-sided breast cancer was significantly different between VMAT and 3D-CRT (p=0.04, Wilcoxon signed-rank test). The volume that received at least 5% of the prescription dose (V5)was less than 25% in the 3D-CRT plan (12.55).For the ipsilateral lung, the V25 parameters were 19.53 ± 10.96, 23.93 ± 13.58 and 20.5 ± 12.32 in IMRT, VMAT and 3D-CRT, respectively. Conclusion From this study, we can conclude that IMRT and VMAT techniques are feasible and can achieve better dosimetric goals for target and OARs though minimizing the area achieving low dose remains to be a dosimetric concern for VMAT.

Is there any additional benefit of 68Ga-PSMA PET on radiotherapy target volume definition in patients with glioblastoma?

To investigate the contribution of 68Gallium (68Ga)-PSMA (prostate-specific membrane antigen) positron emission tomography (PET) in defining radiotherapy (RT) target volume for glioblastoma and to compare the target volumes defined by Magnetic Resonance Imaging (MRI). RT planning Computed Tomography (CT) images were fused separately with pre-operative MRI and PET/MRI images of 10 glioblastoma patients, retrospectively. The contrast-enhanced area in T1 weighted MRI was contoured as gross tumor volume (GTV) and clinical target volume (CTV1) was obtained by including the cavity and T2/FLAIR hyperintense areas after giving a margin of 2 cm to the GTV. 68Ga-PSMA uptake area was contoured as biological tumor volume (BTV) and CTV2 was obtained with a margin of 2 cm to BTV. Planning target volumes (PTVs) were created with the 3 mm added to the CTVs. Conformity index (CI), dice similarity coefficient (DSC) and overlap volume (OV) were calculated by obtaining the intersection and union volumes. Volumetric comparison, similarity and overlap analyzes were performed statistically by Wilcoxon signed rank and One sample t-test. The median GTV was 21,96 cc (1,04 - 82,04) and BTV was 25,58 cc (2,43 - 99,47). BTV was on average 47% larger than GTV which was statistically significant (p = 0.03). For GTV-BTV, CTV1-CTV2 and PTV1-PTV2; mean values of CI were 0,56, 0,76 and 0,76; DSC were 0,70, 0,86 and 0,86; OV were 0,88, 0,94 and 0,94, respectively. There was no significant difference on size and spatial similarity between CTV1 and CTV2, PTV1 and PTV2. Altough BTV was larger than GTV, this significance was lost while we gave the same CTV margin including the peripheral edema. It seems that it may help to improve defining non-enhancing tumor part and also recurrent tumor volume. Recent studies have focused on the role of 68Ga-PSMA PET in imaging of glial tumors. It has been observed that 68Ga-PSMA PET can clearly define the tumor borders and it can be beneficial in target volume delineation, especially in reirradiation of recurrent tumors.

Accuracy of CNN-Based method for segmentation of the mandible

This study aimed to evaluate the accuracy of a new automatic deep learning-based approach for fully mandible automatic segmentation from CBCTs. Forty CBCT scans from healthy patients (20 females, 20 males, mean age 23.37 ± 3.34 years) were collected and a manual mandible segmentation was carried out by using Mimics software. Twenty CBCT scans were randomly selected and used for training the artificial intelligence model file. The remaining 20 CBCT segmentation masks were used to test the accuracy of the CNN fully automatic method by comparing the segmentation volumes of the 3D models obtained with automatic and manual segmentations. The accuracy of this method was also assessed by using the DICE Score coefficient (DSC) and by the surface-to-surface matching technique. The Intraclass correlation coefficient (ICC) and Dahlberg's formula were used to test the intra-observer reliability and method error, respectively. Independent Student's t-test was used for between-groups volumetric comparison. Measurements were highly correlated with an ICC value of 0.937 while the method error was 0.24 mm 3 . An insignificant statistical difference of 0.71 (± 0,49) cm 3 was found between the methodologies (p>0.05). The matching percentage detected was 90.35% ± 1.88 (tolerance, 0.5 mm) and 96.32% ± 1.97% (tolerance 1.0 mm). All volumetric measurements were highly correlated with an ICC value of 0.937 for intra-observer evaluation and 0.919 for inter-observer evaluation. The tested technology provided an accurate fully automated segmentation of the mandible from CBCT scans performing at a much higher speed than an experienced image reader.

Retinal layer segmentation in optical coherence tomography (OCT) using a 3D deep-convolutional regression network for patients with age-related macular degeneration.

Introduction - Retinal layer segmentation in optical coherence tomography (OCT) images is an important approach for detecting and prognosing disease. Automating segmentation using robust machine learning techniques lead to computationally efficient solutions and significantly reduces the cost of labor-intensive labeling, which is traditionally performed by trained graders at a reading center, sometimes aided by semi-automated algorithms. Although several algorithms have been proposed since the revival of deep learning, eyes with severe pathological conditions continue to challenge fully automated segmentation approaches. There remains an opportunity to leverage the underlying spatial correlations between the retinal surfaces in the segmentation approach. Methods - Some of these proposed traditional methods can be expanded to utilize the three-dimensional spatial context governing the retinal image volumes by replacing the use of 2D filters with 3D filters. Towards this purpose, we propose a spatial-context, continuity and anatomical relationship preserving semantic segmentation algorithm, which utilizes the 3D spatial context from the image volumes with the use of 3D filters. We propose a 3D deep neural network capable of learning the surface positions of the layers in the retinal volumes. Results - We utilize a dataset of OCT images from patients with Age-related Macular Degeneration (AMD) to assess performance of our model and provide both qualitative (including segmentation maps and thickness maps) and quantitative (including error metric comparisons and volumetric comparisons) results, which demonstrate that our proposed method performs favorably even for eyes with pathological changes caused by severe retinal diseases. The Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) for patients with a wide range of AMD severity scores (0-11) were within 0.84±0.41 and 1.33±0.73 pixels, respectively, which are significantly better than some of the other state-of-the-art algorithms. Conclusion - The results demonstrate the utility of extracting features from the entire OCT volume by treating the volume as a correlated entity and show the benefit of utilizing 3D autoencoder based regression networks for smoothing the approximated retinal layers by inducing shape based regularization constraints.

The Effect of Mesenchymal Stem Cells on Capsule Formation around Silicone Implant in Rats

ABSTRACT Objective: Capsular contracture is a common adverse effect of breast augmentation and reconstruction surgeries. In the present study we evaluate the effect of adipose tissue-derived mesenchymal stem cells on the capsular structure following breast implant surgery. Materials and Methods: Included in the study were 16 female Wistar-Albino rats, who were divided randomly into two groups. Silicone implants were placed subcutaneously in the pectoral region of the animals in the sham group, while 1 cc of approximately 40 million adipose tissue-derived stem cells were injected into the suture gap after the placement of silicone implants in the experimental group. All experimental animals were re-operated under the same conditions at postoperative week 12 and the implants were removed. All operations were performed by the same surgeon. The capsular structure that had formed around the implants was examined volumetrically and immunohistochemically. Results: Immunohistochemically, the presence of a thick fibrous capsule and prominent procollagen in the periphery was detected in the control group, while capsular staining was noted in the experimental group, wherein thin collagen fibers were organized with the appearance of loose connective tissue, while procollagen staining was lighter and scattered. A volumetric comparison revealed the mean capsule volume to be statistically significantly lower in the experimental group than in the control group. Conclusion: The administration of adipose tissue-derived stem cells resulted in the development of a soft capsule and the formation of new vessels around the implant, and so is likely to have effects that may reduce the development of capsular contracture following breast silicone implant surgery.

Volumetric comparative analysis of anatomy through far-lateral approach: surgical space and exposed tissues

BackgroundThe three-dimensional (3D) visualization model has ability to quantify the surgical anatomy of far-lateral approach. This study was designed to disclose the relationship between surgical space and exposed tissues in the far-lateral approach by the volumetric analysis of 3D model.MethodsThe 3D skull base models were constructed using MRI and CT data of 15 patients (30 sides) with trigeminal neuralgia. Surgical corridors of the far-lateral approach were simulated by triangular pyramids to represent two surgical spaces exposing bony and neurovascular tissues. Volumetric comparison of surgical anatomy was performed using pair t test.ResultsThe morphometric results were almost the same in the two surgical spaces except the vagus nerve (CN X) exposed only in one corridor, whereas the volumetric comparison represented the statistical significant differences of surgical space and bony and neurovascular tissues involved in the two corridors (P<0.001). The differences of bony and neurovascular tissues failed to equal the difference of surgical space.ConclusionsFor far-lateral approach, the increase of exposure for the bony and neurovascular tissues is not necessarily matched with the increase of surgical space. The volumetric comparative analysis is helpful to provide more detailed anatomical information in the surgical design.

A Radiomics-Based Model with the Potential to Differentiate Growth Hormone Deficiency and Idiopathic Short Stature on Sella MRI.

PurposeWe hypothesized that a radiomics approach could be employed to classify children with growth hormone deficiency (GHD) and idiopathic short stature (ISS) on sella magnetic resonance imaging (MRI). Accordingly, we aimed to develop a radiomics prediction model for differentiating GHD from ISS and to evaluate the diagnostic performance thereof.Materials and MethodsShort stature pediatric patients diagnosed with GHD or ISS from March 2011 to July 2020 at our institution were recruited. We enrolled 312 patients (GHD 210, ISS 102) with normal sella MRI and temporally split them into training and test sets (7:3). Pituitary glands were semi-automatically segmented, and 110 radiomic features were extracted from the coronal T2-weighted images. Feature selection and model development were conducted by applying mutual information (MI) and a light gradient boosting machine, respectively. After training, the model’s performance was validated in the test set. We calculated mean absolute Shapley values for each of the selected input features using the Shapley additive explanations (SHAP) algorithm. Volumetric comparison was performed for GHD and ISS groups.ResultsTen radiomic features were selected by MI. The receiver operating characteristics curve of the developed model in the test set was 0.705, with an accuracy of 70.6%. When analyzing SHAP plots, root mean squared values had the highest impact in the model, followed by various texture features. In volumetric analysis, sagittal height showed a significant difference between GHD and ISS groups.ConclusionRadiomic analysis of sella MRI may be able to differentiate between GHD and ISS in clinical practice for short-statured children.

Comparison of Sequential Boost and Simultaneous Integrated Boost Volumetric Modulated Arc Therapy in Treatment of Head and Neck Carcinoma: A Prospective Interventional Study

Introduction: Volumetric Modulated Arc Therapy (VMAT) is a radiotherapy in head and neck cancer can be delivered by two boost techniques: Sequential Boost (SEQ) and Simultaneous Integrated Boost (SIB). There is still limited data comparing these two techniques. Aim: To compare SEQ and SIB planning techniques of VMAT in patients of Head And Neck Squamous Cell Carcinoma (HNSCC) in terms of disease response and acute toxicities. Materials and Methods: A prospective interventional study was conducted at Geetanjali Medical College and Hospital, Udaipur, Rajasthan, India from January 2019 to December 2020. Fifty two patients of HNSCC planned for radical chemoradiation were enrolled into two study arms SEQ-VMAT and SIB-VMAT. Chemotherapy given as weekly cisplatin 40 mg/m2 . Dosimetric comparison was done using Dose Volume Histogram (DVH) analysis. Response evaluation was done as per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 at 8-10 weeks follow-up. Acute toxicity evaluation was done as per Radiation Therapy Oncology Group (RTOG) toxicity grading. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 20.0 software. Results: A total of 52 subjects were included in the study, out of which 26 subjects were included in SEB group while 26 subjects in SIB group. No significant difference was observed in demographic data in terms of age 56.2 vs 53.5 years, sex (24 males and 2 females in both the arms), disease site (oropharynx is the most common site 38.5% in both arms)and stage (IVA 69.2% in SEQ arm vs 46.2% in SIB arm and III 30.8% in SEQ arm vs 42.3% in SIB arm). Dosimetric data was comparable between the two arms. SIB-VMAT shows significantly higher incidence of acute dermatitis (grade1 dermatitis at two weeks 69.2% vs 38.5%, p=0.0279 and grade 2 dermatitis at six weeks 84.6% vs 38.5%, p=0.0007) and acute mucositis (grade 1 mucositis at two weeks 84.6% vs 38.5%, p=0.0007) as compared to SEQ-VMAT. SEQVMAT shows significantly higher incidence of dysphagia (grade 1 at four weeks 84.5% vs 50%, p=0.0087). No significant differences were observed in terms of xerostomia and laryngeal toxicity.No significant difference in overall response was observed between SIB vs SEQ (complete response 65.4% vs 53.85% p=0.40). Conclusion: SEQ appears better in terms of acute toxicities but SIB was more convenient as no re-planning was required. For head and neck radiotherapy SIB and Sequential VMAT are comparable in terms of overall response.

Importance of four-dimensional computed tomography simulation in locally advanced lung cancer radiotherapy: Impact on reducing planning target volume

Background/Aim. Four-dimensional (4D) computed tomography (CT) simulation is a useful tool for motion assessment in lung cancer radiotherapy. Conventional three-dimensional (3D) free-breathing (FB) simulation is static, with limited motion information on respiratory movements that can produce inaccuracies in the delineation process and radiotherapy planning. The aim of this study was to compare clinically significant differences between the target volumes defined on 3D CT vs. 4D CT simulation and the potential impact on the planning target volume (PTV), bearing in mind that a reduced PTV with precise coverage of the primary tumor is extremely important. In addition, quantification of movements of the primary tumor (gross tumor volume ? GTV) was performed during 4D CT simulation on three axes: Z-superoinferior (SI), X-mediolateral (ML), and Y-anteroposterior (AP). Methods. This retrospective study evaluated 20 lung cancer patients who underwent CT simulation for radical radiotherapy treatment. FB 3D CT and 4D CT simulations were acquired for each patient in accordance with our institutional protocol. A volumetric comparison of radiation volumes defined on 3D CT vs. 4D CT simulation was done on the following: GTV 3D vs. internal GTV (IGTV) 4D and PTV 3D vs. internal PTV (IPTV) 4D. The comparison of GTV movement in the FB phase GTV (GTV FB), phase 0 (GTV 0), phase 50 (GTV 50), and phase maximum intensity projection (GTV MIP) was made with GTV FB as the basic value. The evaluation was made on all three axes. Results. The comparison of volumetric values between GTV 3D vs. IGTV 4D was 63.15 cm3 vs. 85.51 cm3 (p &lt; 0.001), respectively. IGTV 4D was significantly larger than GTV 3D (p &lt; 0.001). The mean value of equivalent spherical diameter (ESD) for PTV 3D vs. IPTV 4D was 8.44 cm vs. 7.82 cm (p &lt; 0.001), respectively, and the mean value volume PTV 3D vs. IPTV 4D was 352.70 cm3 vs. 272.78 cm3 (p &lt; 0.001), respectively. PTV 3D was significantly larger than IPTV 4D (p &lt; 0.001). A statistically significant difference (p &lt; 0.05) was identified in the deviation related to the Z-axis between the upper and lower lobe. Conclusion. 4D CT simulation-based delineation can reduce PTV compared to 3D simulation-based radiation therapy; therefore, it is a prerequisite for high-quality and precise radiation therapy treatment.