Lateral Images Research Articles

A Comparative Study of Deep Learning Approaches for Amyotrophic Lateral Sclerosis Super-Resolution Image Classification

Amyotrophic lateral sclerosis is a fatal degenerative neurological disease known as motor neuron disease. According to research, amyotrophic lateral sclerosis affects nerve cells related to movement in the brain and spinal cord, leading to the death of motor neurons, making the brain unable to control muscle movement, and resulting in a significant loss of motor nerve cells, leading to muscle atrophy. In the early stages of ALS, symptoms are mild, often go unnoticed, and can easily be confused with other diseases. Patients may only feel symptoms such as weakness, convulsions, and fatigue, gradually develop muscle atrophy all over the body, difficulty swallowing, and finally die of respiratory failure. TDP-43 is a DNA/RNA binding protein typically located in the nucleus regulating various steps of RNA metabolism. Meanwhile, TDP-43 is the most prominent pathological protein in the characteristics of ALS patients.[1] TDP-43 is depleted in the nucleus in nearly all ALS cases but accumulates in the cytoplasm.Deep learning is learning the internal laws and representation levels of sample data. The information obtained from these learning processes can significantly help interpret data such as text, images, and sounds. Its goal is to enable machines to analyze and learn like humans and recognize data. Additionally, super-resolution microscopy can be used to observe the conformation of proteins in biological samples, thereby gaining insight into the structure and assembly mechanism of TDP-43 aggregates.This project aims to use super-resolution images for machine learning to build a model for classifying ALS patients from non-ALS patients. At the same time, multiple neural network models are used for training and then compared to select the model with the highest accuracy.

Facet joint tropism, pelvic incidence and intervertebral height index: associations with facet joint osteoarthritis in lumbar spinal stenosis

BACKGROUND CONTEXTFacet joint osteoarthritis (FJOA) is associated with lumbar disc degeneration and has a significant role in the development of lumbar spinal stenosis (LSS). The relationship between various radiographic parameters and the grade of FJOA is not well understood. PURPOSETo explore radiographical parameters associated with FJOA in LSS without lumbar dynamic instability. STUDY DESIGNRetrospective study analysis. PATIENT SAMPLEA total of 122 patients diagnosed with LSS who visited our hospital between January 2015 and July 2022. OUTCOME MEASURESWe evaluated radiographic parameters of patients at L4-5 including lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), grades of FJOA, facet joint orientation (FO), facet joint tropism (FT), intervertebral height index (IHI) and the relative cross-sectional area (RCSA) of paraspinal muscles. METHODSPatients diagnosed with LSS between January 2015 and July 2022 were enrolled. Demographic characteristics and radiographic parameters were collected. Spinopelvic parameters were measured through the preoperative lateral image of the whole spine, including LL, PI, pelvic tilt, and sacral slope. Lumbar computed tomography scan and magnetic resonance imaging were collected to measure the FO, FT, IHI, and the RCSA of paraspinal muscles respectively. Patients were divided into three groups according to the severity of FJOA graded by the Weishaupt classification: grade 0 and grade 1 were group A, grade 2 were group B, and grade 3 were group C. All variables were compared among the three groups, while the relationship between parameters and grades of FJOA were also analyzed. RESULTSA total of 122 patients were included. PI was significantly greater in group C compared to group A (p = 0.025) and group B (p=0.022). FT was significantly greater in group C compared to group A (p<.001) and group B (p<.001). The RCSA of multifidus in group A were significantly greater than that in group B (p=0.02) and C (p=0.002). Additionally, FO in group C were significantly lower than group A (p<.001) and group B (p=0.028). The IHI in group C was significantly lower than group A (p=0.017). The correlation analysis indicated that grades of FJOA was positively related to Age, BMI (body mass index), PI, LL and FT, while negatively related to IHI, FO, RCSA of multifidus and RCSA of psoas major. Furthermore, the logistics regression showed that FT, PI, and IHI were important influence factors for FJOA. CONCLUSIONSThe current study confirmed that FT, PI and IHI were significantly associated with grades of FJOA at L4-5. Additionally, longitudinal studies are needed to understand the causal relationship between these parameters and FJOA.

MAxSIM: multi-angle-crossing structured illumination microscopy with height-controlled mirror for 3D topological mapping of live cells

Mapping 3D plasma membrane topology in live cells can bring unprecedented insights into cell biology. Widefield-based super-resolution methods such as 3D-structured illumination microscopy (3D-SIM) can achieve twice the axial ( ~ 300 nm) and lateral ( ~ 100 nm) resolution of widefield microscopy in real time in live cells. However, twice-resolution enhancement cannot sufficiently visualize nanoscale fine structures of the plasma membrane. Axial interferometry methods including fluorescence light interference contrast microscopy and its derivatives (e.g., scanning angle interference microscopy) can determine nanoscale axial locations of proteins on and near the plasma membrane. Thus, by combining super-resolution lateral imaging of 2D-SIM with axial interferometry, we developed multi-angle-crossing structured illumination microscopy (MAxSIM) to generate multiple incident angles by fast, optoelectronic creation of diffraction patterns. Axial localization accuracy can be enhanced by placing cells on a bottom glass substrate, locating a custom height-controlled mirror (HCM) at a fixed axial position above the glass substrate, and optimizing the height reconstruction algorithm for noisy experimental data. The HCM also enables imaging of both the apical and basal surfaces of a cell. MAxSIM with HCM offers high-fidelity nanoscale 3D topological mapping of cell plasma membranes with near-real-time ( ~ 0.5 Hz) imaging of live cells and 3D single-molecule tracking.

Focused ion beams from GaBiLi liquid metal alloy ion sources for nanofabrication and ion imaging

In this work, we present an overview of nanopatterning and imaging applications using newly developed workflows with focused ion beams (FIBs) produced with a GaBiLi liquid metal alloy ion source. The primary beam of this source type contains gallium, bismuth, and lithium as well as cluster ions which can be separated quickly using a Wien filter. Lithium ion milling has been applied to generate heptamer-arranged nanohole arrays in gold films with high resolution. Workflows for two-step bowtie nanofabrication using lithium and bismuth ions from the same source have been established. Furthermore, we present ion beam imaging results that were obtained with lithium ions on various sample materials. Combining the large sputter yield and high depth resolution of heavy bismuth ions with the high lateral imaging resolution of light lithium ions enables 3D nanoscale tomography using different ion species generated from the same source. Sample tilt is not required due to the top-down geometry of the FIB.

Comparison of accuracy of panoramic radiograph and lateral cephalogram in determining linear mandibular measurements among orthodontic patients in tertiary dental care center of Kathmandu

Mandibular dimensions are one of the key parameters for planning the treatment by an Orthodontist. Lateral cephalograms are usually used to evaluate the skeletal relationship. However, due to the superimposition of both the sides, lateral cephalogram may not be reliable in measuring the right and left sides of the cranial landmarks. Panoramic radiography delivers a wide-ranging view of maxillofacial structures with comparatively lesser radiation exposure than other tools and superimposition of structures is less compared to lateral cephalogram image. OPG and lateral cephalograms of all the patients of age group 16-35 years attending Department of Orthodontics in Nepal Medical College from September 2022 to February 2023, having Angle’s Class I Molar relationship with minimum crowding was taken. Linear measurements (ramus height, total mandibular length and mandibular body length) were measured on OPG and Lateral cephalogram. The data was processed in SPSS version 17 for further analysis. There was no statistically significant difference in mean linear measurements between right and left sides on OPG (p-value 0.77, 0.49 and 0.59 respectively). But there was a statistically significant difference in mean linear measurements between both sides on OPG and lateral cephalograms (p-value &lt;0.001). OPG can be used reliably to measure the mandibular length and ramus height of right and left side but comparison of mandibular length and ramus height between lateral cephalogram and OPG may not be reliable.

Performance evaluation of a deep learning-based cascaded HRNet model for automatic measurement of X-ray imaging parameters of lumbar sagittal curvature.

To develop a deep learning-based cascaded HRNet model, in order to automatically measure X-ray imaging parameters of lumbar sagittal curvature and to evaluate its prediction performance. A total of 3730 lumbar lateral digital radiography (DR) images were collected from picture archiving and communication system (PACS). Among them, 3150 images were randomly selected as the training dataset and validation dataset, and 580 images as the test dataset. The landmarks of the lumbar curve index (LCI), lumbar lordosis angle (LLA), sacral slope (SS), lumbar lordosis index (LLI), and the posterior edge tangent angle of the vertebral body (PTA) were identified and marked. The measured results of landmarks on the test dataset were compared with the mean values of manual measurement as the reference standard. Percentage of correct key-points (PCK), intra-class correlation coefficient (ICC), Pearson correlation coefficient (r), mean absolute error (MAE), mean square error (MSE),root-mean-square error (RMSE), and Bland-Altman plot were used to evaluate the performance of the cascade HRNet model. The PCK of the cascaded HRNet model was 97.9-100% in the 3mm distance threshold. The mean differences between the reference standard and the predicted values for LCI, LLA, SS, LLI, and PTA were 0.43mm, 0.99°, 1.11°, 0.01mm, and 0.23°, respectively. There were strong correlation and consistency of the five parameters between the cascaded HRNet model and manual measurements (ICC = 0.989-0.999, R = 0.991-0.999, MAE = 0.63-1.65, MSE = 0.61-4.06, RMSE = 0.78-2.01). The cascaded HRNet model based on deep learning algorithm could accurately identify the sagittal curvature-related landmarks on lateral lumbar DR images and automatically measure the relevant parameters, which is of great significance in clinical application.

Flatfeet Severity-Level Detection Based on Alignment Measuring.

Flat foot is a postural deformity in which the plantar part of the foot is either completely or partially contacted with the ground. In recent clinical practices, X-ray radiographs have been introduced to detect flat feet because they are more affordable to many clinics than using specialized devices. This research aims to develop an automated model that detects flat foot cases and their severity levels from lateral foot X-ray images by measuring three different foot angles: the Arch Angle, Meary's Angle, and the Calcaneal Inclination Angle. Since these angles are formed by connecting a set of points on the image, Template Matching is used to allocate a set of potential points for each angle, and then a classifier is used to select the points with the highest predicted likelihood to be the correct point. Inspired by literature, this research constructed and compared two models: a Convolutional Neural Network-based model and a Random Forest-based model. These models were trained on 8000 images and tested on 240 unseen cases. As a result, the highest overall accuracy rate was 93.13% achieved by the Random Forest model, with mean values for all foot types (normal foot, mild flat foot, and moderate flat foot) being: 93.38 precision, 92.56 recall, 96.46 specificity, 95.42 accuracy, and 92.90 F-Score. The main conclusions that were deduced from this research are: (1) Using transfer learning (VGG-16) as a feature-extractor-only, in addition to image augmentation, has greatly increased the overall accuracy rate. (2) Relying on three different foot angles shows more accurate estimations than measuring a single foot angle.

Evaluation of Hindfoot Alignment on Lateral Weightbearing x-rays: A Novel Prospective In Vivo Study

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: In clinical practice and research, there are several scenarios when a hindfoot alignment view weightbearing XR is not obtained whether as a result of a lack of resources, technology, in retrospective studies when a hindfoot view was not obtained, as well as in many practices where a hindfoot view XR is not considered a routine examination for foot and ankle disorders. A lateral weightbearing radiograph however is almost routinely obtained, and the goal of this study was to correlate the hindfoot alignment angle with measurements on lateral weightbearing images. Methods: Four volunteers (8 feet) with flexible feet and ankles and no symptoms, nor significant trauma &amp; surgical history in their lower limbs were recruited for this study. A portable fluoroscopy machine (Smart C, Turner Imaging, Salt Lake City, USA) was used for imaging. The participant was asked to stand on different custom wooden wedges with the angle changed every 5 degrees from 30 degrees of varus to 30 degrees of valgus and a weightbearing lateral image was taken for each position. The hindfoot alignment was measured using a skin marker which had been drawn prior to initiation of the imaging, and the angular changes of the hindfoot was measured with the placement of each wedge placed. All standardized measurements of the midfoot and hindfoot were obtained on the lateral images. Results: With the hindfoot positional changes between 30o of varus to 30o of valgus, there was a gradual measurable change in the subtalar joint, with corresponding changes in the midfoot and hindfoot. There was a significant linear correlation between the hindfoot alignment angle and all radiographic parameters on lateral images. When the hindfoot alignment angle increased by 1 degree in the valgus direction, there was 0.49o decrease in the pitch angle, 0.58o of decrease in the middle vs posterior facet angle, 0.06o of decrease in the proximal cuneiform/cuboid height, 0.40o of decrease in the proximal cuneiform/5th Metatarsal height, 0.40o of increase in the fifth metatarsal/cuboid height, 0.009o of increase in the sinus tarsi/lateral process height, and 0.015o increase in Cuboid/Anterior Process Height. (Figure 1) Conclusion: The lateral weightbearing XR can be used to predict the status of the hindfoot alignment, and this study has proven that this can be none not only qualitatively but also quantitatively. This novel research can provide our colleagues with linear regression equations to correlate the lateral imaging metrics with the hindfoot alignment angle. Further study with a larger sample size and participants with different types of hindfoot deformities is needed to help develop an algorithm that would help both clinical practice and research.

Radiographic Anatomy of the Lateral Ankle Ligament Complex: A Cadaveric Study

Category: Ankle; Sports Introduction/Purpose: Lateral ankle sprains are common orthopedic injuries that may progress on as chronic lateral ankle instability (CLAI). Great care must be taken to restore precise anatomic relationships of the lateral ankle ligament complex (LALC) in the surgical management of CLAI. This study aimed to quantify the radiographic relationships between the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and prominent osseous landmarks visible under fluoroscopy to assist in perioperative practices for minimally invasive surgery (MIS) for CLAI. Methods: Ten fresh frozen ankle specimens were dissected to expose the LALC and prepared by threading a radiopaque filament through the ligamentous footprints of the ATFL and CFL. Lateral ankle fluoroscopic images were obtained and digitally analyzed to define dimensional characteristics of the ATFL and CFL. Directional measurements of the ligamentous footprints relative to the lateral process of the talus and the apex of the posterior facet of the calcaneus were also calculated. Results: Dimensional measurements of the ATFL included a mean length of 9.3 mm, fibular footprint of 9.4 mm, and talar footprint of 9.1 mm. Dimensional measurements of the CFL included a mean length of 19.4 mm, fibular footprint of 8.2 mm, and calcaneal footprint of 7.3 mm. From the lateral process of the talus, the fibular attachment of the ATFL was found 13.3 mm superior and 4.4 mm posterior, while the talar attachment was found 11.5 mm superior and 4.8 mm anterior. From the apex of the posterior facet of the calcaneus, the fibular attachment of the CFL was found 0.2 mm inferior and 6.8 mm anterior, while the calcaneal attachment was found 14.3 mm inferior and 5.9 mm posterior. Conclusion: The ATFL and CFL were radiographically analyzed in a unique manner and localized in reference to two prominent osseous landmarks. These findings may assist in perioperative practices for keyhole incision placement and arthroscopic guidance.

The Variation Between Unilateral and Bilateral Weight Bearing in Hindfoot Alignment Evaluation. Part I: A Prospective In Vivo Radiographic Study

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: When weight bearing radiographs are taken, the patient is frequently asked to stand on the foot being examined with the other foot lifted off the floor. We have found however that alignments of the hind and midfoot change when bearing weight switches from bilateral to unilateral standing. This study investigated the possible differences in hindfoot alignments between unilateral and bilateral weight bearing using radiographical evaluation. Methods: Eight flexible feet without symptoms symptoms, nor significant trauma &amp; surgical history in their lower limbs were recruited for this study. A portable fluoroscopy machine (Smart C, Turner Imaging, Salt Lake City, USA) was used to take weightbearing lateral views. The patient first stood on both feet with the non-examined foot standing outside of the collimator but bearing weight evenly (Figure 1), and then lifted the non-examined foot off the floor when the lateral XR image was taken for the examined foot. Hindfoot alignment in both positions was reflected by measuring the angle between the long axes of the proximal and distal portions of the Achilles tendon on the skin using the subtalar joint line as the intersection. On lateral XRs, various parameters were measured to reflect the subtalar joint alignment, the position of the calcaneus with inversion and eversion of the hindfoot, and the lateral and medial arch heights. Results: From bearing weight on two feet (bilaterally) to one foot (unilaterally), the Hindfoot Alignment Angle (Achilles) increased (6.23 to 11.21 degrees), the Calcaneal Pitch Angle decreased (22.06 to 19.22 degrees), the Middle vs Posterior Facets Angle decreased (166.46 to 160.74 degrees), and the 5th metatarsal/cuboid height decreased (0.73 to 0.67) all significant changes (p &lt; 0.05). All of these represented a pronation movement in the mid and hindfoot, ie, valgus tilt/eversion of the calcaneus, decreased sinus tarsi opening, and reduced lateral arch height. In this small cohort, these differences were more obvious in the feet that were either slightly flat or cavus shaped (Figure 1, Table 1, and 2) than in feet with a more neutral alignment. Conclusion: The hindfoot and midfoot are more pronated in unilateral weightbearing than in bilateral weightbearing which may mask the severity of the deformity in a flexible cavovarus foot, but increase that in a flexible flatfoot. Modification of the traditionally used unilateral weightbearing position in obtaining clinical radiographs should be considered. Bilateral WBCT scans may be a better alternative, taking advantage of allowing both feet to stand in the most natural position without one foot blocking the other during the radiographic imaging.

New localities and sexual dichromatism in Blue-green eyed Spotted Cuscus Spilocuscus wilsoni Helgen et Flannery, 2004 (Mammalia: Marsupialia: Phalangeridae) from Biak Island, Indonesia

Spotted cuscuses are medium-sized tree-dwelling mammals native to tropical forests of Australo-Papua that primarily feed on fruits and leaves. They belong to the phalangerid genus Spilocuscus (Gray, 1862). The difference in pelage color between male and female Spilocuscus wilsoni has not yet been well described morphologically. In the present study, we describe the coat color of four S. wilsoni individuals: a male adult, a sub-adult male, a sub-adult female, and a juvenile female. Dorsal, lateral, and ventral body section images were captured on camera, and body weight &amp; length, tail &amp; ear length were measured. The adult male S. wilsoni had brown spot and blotch patterns on the dorsal and lateral regions, and the ventral region was plain beige. The sub-adult male had distinct spot patterns without blotches on the dorsal and lateral regions, while the ventral region was plain with a cream base color. The sub-adult female had a mottled pattern that blended with the base color, making a silvery appearance. The female juvenile was spotless throughout, with a foundation hue ranging from creamy to somewhat yellow.

Alignment and characterization of remote-refocusing systems.

The technique of remote refocusing is used in optical microscopy to provide rapid axial scanning without mechanically perturbing the sample and in techniques such as oblique plane microscopy that build on remote refocusing to image a tilted plane within the sample. The magnification between the pupils of the primary (O1) and secondary (O2) microscope objectives of the remote-refocusing system has been shown previously by Mohanan and Corbett [J. Microsc.288, 95 (2022)JMICAR0022-272010.1111/jmi.12991] to be crucial in obtaining the broadest possible remote-refocusing range. In this work, we performed an initial alignment of a remote-refocusing system and then studied the effect of axial misalignments of O1 and O2, axial misalignment of the primary tube lens (TL1) relative to the secondary tube lens (TL2), lateral misalignments of TL2, and changes in the focal length of TL2. For each instance of the setup, we measured the mean point spread function F W H M xy of 100nm fluorescent beads and the normalized bead integrated fluorescence signal, and we calculated the axial and lateral distortion of the system; all of these quantities were mapped over the remote-refocusing range and as a function of lateral image position. This allowed us to estimate the volume over which diffraction-limited performance is achieved and how this changes with the alignment of the system.

The safe zone of distal fibula was determined based on the classification of lateral malleolus fossa

BackgroundLateral malleolus fractures are very common, and the distal fibular geometry is complex. This study aimed to classify the lateral malleolus fossa (MF) into different types by characterizing the lateral MF imaging morphology and exploring the relationship between the lateral MF and internal fixation position after distal fibula fractures.MethodsAnteroposterior CT reconstruction was performed on 248 subjects. After reconstruction, the deepest point of the lateral MF was located, and then, the cross-sectional shape of the lateral MF was observed and classified.ResultsAccording to the morphology of the CT cross section, the lateral MF was divided into three types: type C (43.1%), type V (32.2%), and type Flat (24.7%). Type V (3.98 ± 0.82) was significantly longer than type C(2.83 ± 0.54) and type Flat (1.84 ± 0.42) in cd. Similarly, in ∠α, Type Flat(136.31 ± 9.63) was the largest, followed by type C (116.51 ± 8.79), and type V (89.31 ± 9.07) was the smallest. Other measurements were not found any significant differences between the above.ConclusionAccording to the morphology of the CT cross section, the lateral MF was divided into three types: type C, type V and type Flat. Type V is most likely to be invaded when fixing the distal fibula. Screws less than 9 mm should be selected when fixing, and screws no more than 10 mm should be selected when there are type C and type Flat of MF.

Breast Reconstruction With Simultaneous Bilateral Lumbar Artery Perforator Flaps Improves Waistline Definition and Buttock Projection.

The lumbar artery perforator (LAP) flap is a valuable secondary option for autologous breast reconstruction when abdominal donor sites are not available. The aim of this study was to determine how the LAP donor site affects waistline and gluteal proportions, and whether LAP flaps may produce potential secondary benefits concerning donor site aesthetics. A retrospective review of 50 patients who underwent bilateral breast reconstruction with LAP flaps (100 flaps) between 2018 and 2022 was performed. Patient characteristics and postoperative complications were recorded. Pre- and postoperative standardized frontal and lateral patient photographs were analyzed to identify postoperative changes in waist-to-hip ratio (WHR) to assess waistline definition and buttock projection. The patients' individual perception of postoperative aesthetic changes to their waistline and buttocks was determined by an electronic survey. The patients had a mean age of 51 years (range, 24-63 years) and a mean BMI of 26.9 kg/m2 (range, 19.3-37.4 kg/m2). Postoperative donor site complications included seroma (n = 10), wound dehiscence (n = 5), hematoma (n = 4), and wound infection (n = 2). Flap loss rate was 2%. After reconstruction, patients were found to have a more defined waistline, indicated by a significantly decreased WHR on frontal images (mean [standard error of the mean], 0.85 [0.05] vs 0.80 [0.05], P < .005) and a more projected buttocks indicated by a significant reduction in WHR on lateral images (0.92 [0.07] vs 0.87 [0.07], P < .0001). Among the patients who responded to the survey, 73% indicated that their waistline had aesthetically improved, 6.7% felt it had not changed, and 20% felt that it had worsened. An aesthetic improvement of the buttocks was reported by 53%, 40% felt their buttocks had not changed, and 6.7% felt their buttocks appearance had worsened. Bilateral LAP flap breast reconstruction leads to improved waistline definition and buttock projection, bringing patients closer to ideal aesthetic proportions. This reconstructive approach is ideal for patients who are not candidates for abdominal free flaps, but who demonstrate excess flank tissue and seek a more defined waistline and projected buttocks.

Microwave Angiography by Ultra-Wideband Sounding: A Preliminary Investigation.

Angiography is a very informative method for physicians such as cardiologists, neurologists and neuroscientists. The current modalities experience some shortages, e.g., ultrasound is very operator dependent. The computerized tomography (CT) and magnetic resonance (MR) angiography are very expensive and near infrared spectroscopy cannot capture the deep arteries. Microwave technology has the potential to address some of these issues while compromising between operator dependency, cost, speed, penetration depth and resolution. This paper studies the feasibility of microwave signals for monitoring of arteries. To this aim, a homogenous phantom mimicking body tissue is built. Four elastic tubes simulate arteries and a mechanical system creates pulsations in these arteries. A multiple input multiple output (MIMO) array of ultra-wideband (UWB) transmitters and receivers illuminates the phantom and captures the reflected signals over the desired observation time period. Since we are only interested in the imaging of dynamic parts, i.e., arteries, the static clutters can be suppressed easily by background subtraction method. To obtain a fast image of arteries, which are pulsating with the heartbeat rate, we calculate the Fourier transform of each channel of the MIMO system over the observation time and apply delay and sum (DAS) beamforming method on the heartbeat rate aligned spectral component. The results show that the lateral and longitudinal images and motion mode (M-mode) time series of different points of phantom have the potential to be used for diagnosis.

Lateral lymph node involvement presents another challenge in rectum cancer in the age of neoadjuvant chemoradiotherapy + total mesorectal excision: an evaluation of survival outcomes.

In the last decades, total mesorectal excision (TME) and neoadjuvant chemoradiotherapy (nCRT) have produced an undeniable improvement in the treatment of rectal cancer. However, local recurrence is still an important problem, and the effect of lateral lymph node (LLN) involvement on local recurrence is a controversial issue. The aim of this study was to investigate the effects of LLN status on local recurrence and survival in rectal cancers treated with nCRT + TME. Clinical features, pre- and post-nCRT lateral pelvic region imaging, long-term local recurrence, and the survival outcomes of 114 patients who underwent nCRT + TME for rectal cancer were evaluated. On MRI before nCRT, 20 (17.5%) patients had lateral lymph nodes (LLN+), and 94 (82.5%) patients had no lymph nodes in the lateral pelvic compartments (LLN-). Local recurrences at 1 year in LLN+ and LLN- patients were 3 (15.8%) and 2 (2.3%), respectively (p=0.039). Five-year local recurrence-free survival rates and the mean duration of recurrence-free survival in LLN+ and LLN- patients were 56.2%, 42.6 months, and 87.3% 66.9 months, respectively (p=0.001). Disease-free survival and overall survival were shorter in LLN+ patients, but the difference was not statistically significant (p=0.096 and p=0.46, respectively). In the multivariate analysis, LLN involvement was determined to be an independent risk factor for local recurrence-free survival (Hazard Ratio 4.54, p=0.003). Lateral lymph node involvement causes local recurrence to remain high after nCRT + TME. LLN status should be considered in treatment planning. Further studies are needed to define precise criteria for LLN involvement and the effect of LLND on local recurrence and survival.

2D cross-hole electromagnetic inversion algorithms based on regularization algorithms

Abstract The cross-hole electromagnetic (EM) method, which is currently at the forefront of electric logging technology, fundamentally solves the problems of the lateral imaging ability of single-well logging and the lack of detection of inter-well physical properties. However, due to the complexity of underground reservoir distribution and the non-uniqueness problem of geophysical inversion, there remains a lack of practical and effective cross-hole electromagnetic inversion methods. Our goal is to develop an efficient method to reduce the non-uniqueness of the physical property model recovered in the inversion. It is worth noting that the regularization algorithm, as a means to approximately solve inversion problems, can obtain different solutions by changing the form of the regularization function, so as to ensure the stability of inversion results and conform to the smooth or non-smooth characteristics in known geology or geophysics. We adjust the features of the final inversion model in a defined framework by changing the values of the $\alpha $ coefficient in the regularization and using the Lawson norm as a ${l}_p$-norm approximation form for $p \in [ {0,2} ]$. At the same time, the iteratively reweighted least-squares method is used to solve the optimization problem, and the gradient in the Gauss–Newton solution is adjusted successively to ensure that every term in the regularization contributes to the final solution. Compared with the traditional ${l}_2$-norm inversion method, the sparse inversion method can make more effective use of information regarding known physical properties and obtain better inversion results. Then, the effectiveness of our inversion method is verified by model tests and inversion of measured data in a mining area.

Effect of Pumice Powder on Mechanical, Thermal, and Water Absorption Properties of Fiberboard Composites

Abstract Composites were produced using medium-density fiberboard (MDF) flour with pumice powder which was mixed at various ratios by the hand lay-up technique. Mechanical properties, such as tensile and three-point bending strengths, were determined by ASTM D3039 and ASTM D790 respectively. The best three-point bending and tensile strength properties were maximum values obtained from composites containing 20wt% pumice powder (pp) and 50wt% pumice powder (pp) respectively. It is observed that the water absorption rate into the composites decreases with an increase in the pumice powder-to-ratio. The composite filled with 50wt%pumice powder absorbed the least amount of water compared to the other composites. All composites were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and differential scanning calorimetry analysis (DSC). SEM images revealed a near-homogeneous surface partly free of defects and holes. However, lateral profile images showed the presence of MDF flour particles agglomerated and a considerable number of bubbles and cavities that could interfere with the mechanical properties of the composites. The results of the mechanical, and thermal properties suggested that pumice powder epoxy composites with MDF flour can increase their tensile, three-point-bending strength, and glass transition temperature for the pure MDF flour composite.

Comparison of linear and angular measurements in mandibular symphyseal region using lateral cephalometric and cone beam CT images

AbstractAimTo compare the linear and angular measurements of the mandibular symphyseal region using lateral cephalometric (LC) and cone beam computed tomography (CBCT) images.Materials and MethodsOne hundred patients justifying both LC and CBCT exposures were included. Both lateral cephalometric and CBCT images of the patients were used for angular and linear measurements. Angular measurements included vestibular concavity and lingual and tooth inclination angles. Vestibular and lingual cortical bone and total bone thickness measurements were obtained for the comparison of linear measurements. Three radiologists performed the measurements on 200 images. Comparison of the measurements and the imaging methods were done using paired‐ and Wilcoxon t‐tests. Inter‐observer reliability was evaluated with the intra‐class correlation coefficient (ICC).ResultsA significant difference was observed between measurements of two imaging methods for tooth inclination and vestibular concavity angles; however, no difference was found between LC and CBCT measurements for lingual inclination angle (p &gt; 0.05). Vestibular cortical bone and total bone thickness measurements showed a significant difference (p &lt; 0.05), whereas no difference was obtained in lingual bone thickness measurements of two imaging methods (p &gt; 0.05).ConclusionCBCT imaging is recommended in selected patients where recipient bone or bone augmentation site(s) reveal suspect in clinical examination and lateral cephalometric imaging may not reveal the true anatomic structure and relationships.

Audit of upper gastrointestinal tract series examinations for diagnosing intestinal malrotation in a resource-limited radiology department in Southern Africa

Intestinal malrotation is a congenitally acquired condition of abnormally rotated proximal small bowel in neonates and infants. Prompt recognition prevents lifethreatening complications. A structured approach to diagnosing malrotation at UGIS is required for accurate diagnosis. Retrospective analysis of the images and radiological reports of UGIS, with the aim of identifying potential shortfalls in diagnosing malrotation. A secondary objective is to formulate a reporting template to improve overall quality of UGIS reports, specifically in cases of suspected malrotation. Identification and retrospective review of UGIS studies which were subsequently re-read by a blinded consultant radiologist using the proposed reporting template adapted from the literature. 367 UGIS studies between 1 January 2016 and 31 December 2021 were included in the study cohort, which were then re-read. Using McNemar's chi-square test, we found discrepancy between the number of studies positive for malrotation on the original reports versus the re-read studies, highlighting shortfalls in our current practise. A structured approach is paramount to the correct diagnosis of malrotation at UGIS. The position of the DJ-flexure (on frontal and lateral projections) proves most sensitive and specific in the diagnosis of malrotation at UGIS. Dedicated true lateral images were often found to be excluded in daily practise. We propose a structured inclusive reporting template. Our proposed standardized reporting template aims to improve radiological, clinical, and surgical outcomes at UGIS, specifically in patients with suspected malrotation.