Three-dimensional Computed Tomography Research Articles

The Assessment of Airway Compression Due to Cervical Fusion in Klippel-Feil Syndrome Patients: A Report of Two Cases.

In general anesthesia for Klippel-Feil syndrome (KFS) patients, there is a potential risk of difficult intubation. However, airway assessment to predict difficult intubation for KFS patients is not known. In Patient 1, cervical spine computed tomography (CT) revealed airway compression due to cervical fusion. For airway assessment, bronchofiberscopy, three-dimensional (3-D) CT, and virtual bronchoscopic image (VBI) construction were performed. Based on these images, fiberoptic nasotracheal awake intubation was performed. In Patient 2, magnetic resonance imaging and bronchofiberscopy showed no airway compression due to cervical fusion; therefore, tracheal intubation was performed using a video laryngoscope after anesthetic administration. Airway compression due to cervical fusion is considered one of the risk factors for difficult intubation in KFS patients.

Laparoscopic Colectomy for Cecal Cancer and Intestinal Malrotation: A Case Report.

Intestinal malrotation (IM) often remains undetected until adulthood, being discovered during testing or surgery for other comorbidities. Preoperative understanding of this anatomical abnormality is crucial. An 80-year-old woman presented with cecal cancer. Three-dimensional computed tomography (CT) revealed that the cecum was located at the midline of the abdominal cavity, the duodenum did not cross the midline, and the ileocolic vein ran to the left. Clinically diagnosed with stage IVc cecal cancer complicated by IM, the patient underwent laparoscopic surgery. The ascending colon and cecum were not fixed to the retroperitoneum. The duodenum lacked the second, third, and fourth portions and the small bowel was distributed on the left and right sides of the abdominal cavity. Adhesions had shortened the mesentery, which were released close to their normal positions. Although laparoscopic surgery is superior to open surgery in terms of securing the field of view in a narrow space, providing a magnifying effect, and minimal invasiveness, it has a limited field of view and is inferior in terms of grasping the overall anatomy, which may be disadvantageous in cases of anatomical abnormalities. Colorectal cancer with IM is rare; however, the rate of preoperative diagnosis seems to be increasing thanks to improvements in diagnostic imaging, such as three-dimensional CT scans. In this study, we also reviewed 49 cases of colorectal cancer associated with IM.

DP-GAN+B: A lightweight generative adversarial network based on depthwise separable convolutions for generating CT volumes

X-rays, commonly used in clinical settings, offer advantages such as low radiation and cost-efficiency. However, their limitation lies in the inability to distinctly visualize overlapping organs. In contrast, Computed Tomography (CT) scans provide a three-dimensional view, overcoming this drawback but at the expense of higher radiation doses and increased costs. Hence, from both the patient's and hospital's standpoints, there is substantial medical and practical value in attempting the reconstruction from two-dimensional X-ray images to three-dimensional CT images. In this paper, we introduce DP-GAN+B as a pioneering approach for transforming two-dimensional frontal and lateral lung X-rays into three-dimensional lung CT volumes. Our method innovatively employs depthwise separable convolutions instead of traditional convolutions and introduces vector and fusion loss for superior performance. Compared to prior models, DP-GAN+B significantly reduces the generator network parameters by 21.104 M and the discriminator network parameters by 10.82 M, resulting in a total reduction of 31.924 M (44.17%). Experimental results demonstrate that our network can effectively generate clinically relevant, high-quality CT images from X-ray data, presenting a promising solution for enhancing diagnostic imaging while mitigating cost and radiation concerns.

The Origin and Course of the Blood Supply to the Lower Eyelid Orbital Fat: Anatomical Study and Clinical Significance.

The aim of this study is to investigate the origin and course of the orbital fat arterial supply in the lower eyelid using traditional anatomy and three-dimensional computed tomography (CT). Twenty-seven cadaver heads were infused with mercury sulfide contrast media through the ophthalmic artery, maxillary artery, transverse facial artery, and facial artery. CT images were obtained after contrast agent injection, three-dimensional CT scans were reconstructed, and the cadaver heads were dissected. Forty-five qualified hemifaces showed that the orbital fat arterial supply in the lower eyelid originates primarily from the inferomedial muscular trunk (IMT) of the ophthalmic artery and the orbital branch of the infraorbital artery. The medial branch of the IMT terminated at the medial fat pad (35.6%) or the orbital floor (64.4%). The lateral branch terminated at the inferior oblique (IO) muscle (28.9%) or the central and lateral fat pads (17.8%). In 53.3%, the lateral branch extended to the anterior part of the lateral fat pad and terminated in the orbital wall or the zygomaticoorbital foramina. The orbital branch of the infraorbital artery coursed between the orbital floor and the orbital fat, providing supply to the IO muscle, inferior rectus (IR) muscle, nasolacrimal duct, and orbital fat. This study elucidated the origin and course of the orbital fat arterial supply in the lower eyelid, which may help to avoid reducing the blood supply of the orbital fat pedicles during surgery. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Terahertz bistatic three-dimensional computational imaging of hidden objects through random media

Random media pose limitations on the imaging capability of photoelectric detection devices. Currently, imaging techniques employed through random media primarily operate within the laser wavelength range, leaving the imaging potential of terahertz waves unexplored. In this study, we present an approach for terahertz bistatic three-dimensional imaging (TBTCI) of hidden objects through random media. By deducing the field distribution of bistatic terahertz time-domain spectroscopy system, and proposing an explicit point spread function of the random media, we conducted three-dimensional imaging of hidden objects obscured by the random media. Our proposed method exhibits promising applications in imaging scenarios with millimeter-wave radar, including non-invasive testing and biological imaging.

Evaluation of glenoid morphology and bony Bankart lesion in shoulders with traumatic anterior instability using zero echo time magnetic resonance imaging

BackgroundPreoperative computed tomography (CT) evaluation of bone morphometry aids in determining treatment strategies for shoulder instability. The use of zero echo time (ZTE) sequence in magnetic resonance imaging (MRI), a new bone cortex imaging technique, may help reduce radiation exposure and medical costs. Therefore, this study aimed to evaluate the glenoid morphology and detect the presence of bony Bankart lesion using ZTE MRI in shoulders with anterior instability and compare its diagnostic accuracy with that of CT. MethodsThirty-six patients (36 shoulders) with anterior instability who underwent preoperative CT and MRI examinations between April 2019 and October 2021 were retrospectively analyzed. The percentages of glenoid bone defects on three-dimensional (3D) CT and ZTE images were determined, and the correlation between these percentages was evaluated. The number of cases with bony Bankart lesion on CT and two types of ZTE (3D and CT-like) images was determined, and the diagnostic accuracy of ZTE for detecting bony Bankart lesion was assessed, with CT as the gold standard. Patients with bony Bankart lesion on CT images were divided into two groups based on whether the lesion was detectable on 3D ZTE or CT-like images. The longer diameters of bony Bankart lesion were compared between the groups. ResultsThe median percentage of glenoid bone loss was 12.1% (range, 1.3%–45.9%) and 12.3% (range, 0%–46.6%) on 3D CT and 3D ZTE images, respectively. The Spearman’s rank correlation coefficient was 0.89. Bony Bankart lesion was detected in 18, 13, and eight shoulders of the 36 patients on CT, 3D ZTE, and CT-like images, respectively. The overall diagnostic accuracy of the CT-like and 3D ZTE images for detecting bony Bankart lesion was 86.1% and 72.2%, respectively. A significant difference was observed between the groups with and without bony Bankart lesion on CT-like images in terms of the long diameter of the bone fragments on CT (p < 0.01). ConclusionsZTE MRI demonstrated high reproducibility for the evaluation of glenoid bone defect in shoulders with anterior instability. Although no significant difference in the measurement was observed compared with that on CT, the ability of ZTE MRI to delineate bone Bankart lesion remains limited.

Automated Midline Shift Detection and Quantification in Traumatic Brain Injury: A Comprehensive Review

AbstractTraumatic brain injury (TBI) often results in midline shift (MLS) that is a critical indicator of the severity and prognosis of head injuries. Automated analysis of MLS from head computed tomography (CT) scans using artificial intelligence (AI) techniques has gained much attention in the past decade and has shown promise in improving diagnostic efficiency and accuracy. This review aims to summarize the current state of research on AI-based approaches for MLS analysis in TBI cases, identify the methodologies employed, evaluate the performance of the algorithms, and draw conclusions regarding their potential clinical applicability. A comprehensive literature search was conducted, identifying 15 distinctive publications. The identified articles were analyzed for their focus on MLS detection and quantification using AI techniques, including their choice of AI algorithms, dataset characteristics, and methodology. The reviewed articles covered various aspects related to MLS detection and quantification, employing deep neural networks trained on two-dimensional or three-dimensional CT imaging datasets. The dataset sizes ranged from 11 patients' CT scans to 25,000 CT images. The performance of the AI algorithms exhibited variations in accuracy, sensitivity, and specificity, with sensitivity ranging from 70 to 100%, and specificity ranging from 73 to 97.4%. AI-based approaches utilizing deep neural networks have demonstrated potential in the automated detection and quantification of MLS in TBI cases. However, different researchers have used different techniques; hence, critical comparison is difficult. Further research and standardization of evaluation protocols are needed to establish the reliability and generalizability of these AI algorithms for MLS detection and quantification in clinical practice. The findings highlight the importance of AI techniques in improving MLS diagnosis and guiding clinical decision-making in TBI management.

Predictive Value of Vertebral Bone Destruction Classification Based on Computed Tomography in Diagnosing on Adult Spinal Tuberculosis

Although magnetic resonance imaging (MRI) is well established for evaluation of spinal tuberculosis (TB), the importance of computed tomography (CT) should not be overlooked. The purpose of this study was to determine the characteristics of spinal TB and the relationship between spinal TB and the bone lesion pattern seen on three-dimensional CT images. One hundred and sixty-one subjects were divided into a TB-positive group and a TB-negative group based on laboratory (X-pert MTB/RIF) results and then subdivided further according to whether the bone lesion pattern seen on three-dimensional CT images was fragmentary, osteolytic, sclerotic, or had no evidence of bone destruction. The diagnostic value of the bone lesion pattern was compared between the TB-positive and TB-negative groups. Ninety-nine of the 161 patients were TB-positive and 62 were TB-negative. Fifty-six (34.8%) of the 161 patients had fragmentary/osteolytic lesions, seventy-four (45.9%) had absolute osteolytic lesions, 13 (8.1%) had osteosclerotic lesions, and 18 (11.2%) had no evidence of bone destruction. The fragmentary/osteolytic lesion pattern was strongly predictive of spinal TB (odds ratio 3.33), and when combined with three MRI findings (thin abscess wall, more than half of the vertebral body destroyed, and subligamentous spread) had an even stronger diagnostic value (odds ratio 15.58). The absolute osteolytic pattern was the most common of the bone lesion patterns. The fragmentary/osteolytic pattern is highly suggestive of spinal TB, especially when combined with MRI findings of a thin abscess wall, destruction of more than half of the vertebral body, and subligamentous spread.

Development of a Mind Map-based Predictive Nursing Protocol and its Impact on the Clarity of Images in Patients Undergoing High-concentration Contrast Three-dimensional Computed Tomography Imaging of Liver Blood Vessels.

To explore the development of a mind map-based predictive nursing protocol and assess its impact on the quality of images in patients undergoing high-concentration contrast three-dimensional computed tomography (CT) imaging of liver blood vessels. A total of 600 patients who were admitted to Beijing You an Hospital were chosen for this prospective study and underwent high-concentration contrast three-dimensional CT imaging of liver blood vessels between April 2021 and December 2021. The patients were divided into two groups using the digital table method, with 300 cases. The control group received conventional nursing intervention, while the research group was provided with a mind map-based predictive nursing protocol. We recorded the image quality of three-dimensional CT imaging of liver blood vessels, satisfaction scores regarding nurse examination guidance, and the Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) in both groups. The research group achieved a perfect rate of 100.00% for the high-quality three-dimensional CT imaging of liver blood vessels, which was noticeably higher compared to the rate of the control group of 98.67%. Patients in the research group expressed higher satisfaction levels regarding the guidance provided by nurses, including their attitude, timeliness, accuracy, and overall satisfaction, compared to the control group. Initially, the two groups had no notable differences in the SAS and SDS scores. However, after the intervention, both groups experienced a significant decrease in SAS and SDS scores, with the research group showing an even more substantial decline. Through the creation of a mind map-based predictive nursing protocol and its implementation on patients undergoing high-concentration contrast three-dimensional CT imaging of liver blood vessels, it is possible to significantly enhance the quality of CT scans, alleviate feelings of anxiety and depression, increase patient satisfaction with examination guidance by nurses, and effectively decrease the occurrences of contrast agent leakage and allergic reactions to iodine.

Multidimensional characterization of particle morphology and mineralogical composition using CT data and R-vine copulas

Computed tomography (CT) can capture volumes large enough to measure a statistically meaningful number of micron-sized particles with a sufficiently good resolution to allow for the analysis of individual particles. However, the development of methods to efficiently investigate such image data and interpretably model the observed particle features is still an active field of research. When image data of particles exhibiting a wide range of shapes and sizes is considered, traditional image segmentation methods, such as the classic watershed algorithm, struggle to recognize particles with satisfying accuracy. Thus, more advanced methods of machine learning must be utilized for image segmentation to improve the validity of subsequent analyses. Moreover, CT data does not include information about the mineralogical composition of particles and, therefore, additional SEM-EDS image data has to be acquired. In this paper, micro-CT image data of a particle system mostly consisting of zinnwaldite–quartz composites is considered. First, an image segmentation method is applied which uses deep convolutional neural networks, in particular an adaptation of the U-net architecture. This has the advantage of requiring less hand-labeling than other machine learning methods, while also being more flexible with the possibility of transfer learning. Then, fully parameterized models based on vine copulas are designed to determine multivariate probability distributions of descriptor vectors for the size, shape, texture and composition of particles—allowing for the estimation and interpretable characterization of interdependencies between particle descriptors. For model fitting, the segmented three-dimensional CT data and co-registered two-dimensional SEM-EDS data are used. The models are applied to predict the mineralogical composition of particles, solely on the basis of particle descriptors observed in CT data.

Reference Range of CT Value in NC-CBBCT Based on Female Breast Structure.

As a new high-resolution three-dimensional CT imaging technology, the essential reference range of CT values in Cone-beam breast computed tomography (CBBCT) has not been established to date. To determine the reference range of computed tomography (CT) values in CBBCT for clinical breast examination. In total, 913 cases (1167 lateral) were subject to CBBCT. CT values of the glandular tissue, fat and different quadrants and different distances of CBBCT images were analyzed. The nipple and muscle were also evaluated. A total of 672 lateral breasts were included in the normal group for investigation. The reference range of the absolute CT value of the chest wall muscle is -136.68~43.36 HU. The reference range of the absolute CT value of the nipple is 176.39~334.02 HU. The reference range of the absolute CT value of fat is -190.4~-63.67HU, and of glandular tissue is -12.2~199.07HU. Our results firstly established the baseline CT values of Non-contrast CBBCT in female breasts, which will benefit cancer screening and lesion locating. The closer the normal breast fat and glandular tissue is to the nipple, the greater the CT value. The older the age, the lower the density. The CT values of fat are unstable in a distance of less than 5 cm, and the CT values of glandular tissues are relatively stable. The difference between the upper and lower quadrants is significant in the same lateral breast and the same section.

Heart Dose Uncertainty Caused by Heartbeat during Adjuvant Breast Radiotherapy

Adjuvant radiotherapy is a crucial treatment option for breast cancer. Owing to the long survival after treatment, heart toxicity has become a critical issue in those who receive radiotherapy. The heart dose is calculated using the computed tomography (CT) images acquired during simulation. The heart volume is quite different between the systolic and diastolic phases. This study used four-dimensional (4D) CT to capture the heart image and determine the ranges of the heart dose in different phases of the heart. Patients with left-sided breast cancer who underwent breast conservative surgery followed by adjuvant radiotherapy to the entire breast between January 2016 and December 2021 were identified. The three-dimensional (3D) CT and 4DCT datasets of the patients were acquired to evaluate the variation in the heart dose. The heart volume in each respiratory phase was depicted in a box plot along with the dice similarity coefficient (DCS). A total of 32 patients met the inclusion criteria. The DCS of the heart in each respiration phase was within the range of 0.91 to 0.95. Variations in the heart volume and morphology were not evident. However, these variations were not influenced by the respiratory cycle. The median relative variations in the 4DCT volume, mean dose, V20 (≥20 Gy), and V40 (40 Gy) were 6%, 14%, 19%, and 32%, respectively. All parameters showed significant variation between the maximum values in 4DCT and planning 3DCT. When parameters in planning 3DCT were compared to minimum values in 4DCT, the heart volume and V20 still showed significant differences, whereas the mean dose (p = .052) and V40 (p = .151) did not. We found that the median variation in the heart volume during the respiratory cycle was 6%, which led to a 14% variation in the mean heart dose, 19% in V20, and 32% in V40. Dose variation should not be ignored. A more precise method for estimating the heart dose during treatment should be investigated.

Tree Core Analysis with X-ray Computed Tomography.

An X-ray computed tomography (CT) toolchain is presented to obtain tree-ring width (TRW), maximum latewood density (MXD), other density parameters, and quantitative wood anatomy (QWA) data without the need for labor-intensive surface treatment or any physical sample preparation. The focus here is on increment cores and scanning procedures at resolutions ranging from 60 µm down to 4 µm. Three scales are defined at which wood should be looked at: (i) inter-ring scale, (ii) ring scale, i.e., tree-ring analysis and densitometry scale, as well as (iii) anatomical scale, the latter approaching the conventional thin-section quality. Custom-designed sample holders for each of these scales enable high-throughput scanning of multiple increment cores. A series of software routines were specifically developed to efficiently treat three-dimensional X-ray CT images of the tree cores for TRW and densitometry. This work briefly explains the basic principles of CT, which are needed for a proper understanding of the protocol. The protocol is presented for some known species that are commonly used in dendrochronology. The combination of rough density estimates, TRW and MXD data, as well as quantitative anatomy data, allows us to broaden and deepen current analyses for climate reconstructions or tree response, as well as further develop the field of dendroecology/climatology and archeology.

Incidence and outcomes of intraoperative periprosthetic acetabular fractures during cementless total hip arthroplasty: a prospective three-dimensional computer tomography-based study.

Unlike periprosthetic femoral fractures, periprosthetic acetabular fractures during total hip arthroplasty (THA) have not been evaluated in detail. We prospectively evaluated the incidence, patterns, risk factors, and clinical outcomes of intraoperative periprosthetic acetabular fractures using pre- and postoperative computer tomography (CT). In this prospective single-centre study, we evaluated 234 consecutive patients (250 hips) who underwent THA and three-dimensional CT before and after the surgery. We assessed the incidence, pattern of fractures, outcomes for each fracture pattern, reoperation and revision rates, Harris hip score, and visual analog scale (VAS) for pain. Multivariate regression models were used to identify risk factors for periprosthetic acetabular fractures. In total, 43 periprosthetic acetabular fractures (17.2%) were identified via CT. Fractures occurred most frequently at the superolateral wall. Early cup migration occurred in three hips. None of the patients underwent revision surgery for acetabular loosening. Regression modeling showed that rheumatoid arthritis was a significant predictor of periprosthetic acetabular fractures. Periprosthetic acetabular fractures are not infrequent during cementless THA and are more common in patients with rheumatoid arthritis.

Double inferior vena cava, an uncommon but relevant anatomical anomaly in surgery for lower rectal cancer: a report of two cases

BackgroundDouble inferior vena cava (DIVC) is rare and usually detected incidentally. DIVC may be associated with several anatomical variants of the retroperitoneal and pelvic veins. These variants can pose a clinical problem during colorectal surgery. We present two patients with lower rectal cancer who also had a DIVC.Case presentationCase 1 was a 72-year-old man with advanced lower rectal cancer (T3N0M0) who underwent robot-assisted low anterior resection after neoadjuvant therapy. A DIVC was detected on preoperative computed tomography (CT). During the operation, a presacral vein was injured while mobilizing the rectum and hemostasis could not be achieved. We converted to open surgery and packed the pelvic cavity for hemostasis. Retrospective analysis suggested the injured vein arose from an interiliac vein of the presacral pelvic venous plexus. Case 2 was a 50-year-old woman with lower rectal cancer (T3N0M0), immune thrombocytopenic purpura, and a DIVC. Although preoperative three-dimensional CT angiography showed no obvious pelvic vein abnormalities, a short course of preoperative radiotherapy was delivered to avoid lateral pelvic lymph node dissection. Chemotherapy was deferred owing to her thrombocytopenic disease. Laparoscopic abdominoperineal resection was performed meticulously to minimize bleeding and achieve rapid hemostasis. No intraoperative complications occurred.ConclusionDIVC is often accompanied by venous malformations that may pose a problem when mobilizing the mesorectum from the retroperitoneum. Preoperative assessment of pelvic vessel anatomy using three-dimensional CT is essential in patients with a DIVC who undergo rectal surgery.

Prognostic impact of highly solid component in early-stage solid lung adenocarcinoma.

Based on computed tomography (CT) findings of lung cancer, solid nodules have a much worse prognosis than subsolid nodules, even if the nodules are subcentimeter in size. There is, however, no systematic method for determining the prognosis of solid tumors on CT. This study aimed to discover the prognostic factor of early-stage solid lung adenocarcinoma using three-dimensional CT volumetry. Patients with pathological stage I solid lung adenocarcinoma who underwent complete resection between 2007 and 2012 were selected in this retrospective study. Clinicopathological data and preoperative multidetector CT findings, such as tumor size on the two-dimensional axial image, three-dimensional tumor volume between -600 and 199 HU, and three-dimensional solid volume between 0 and 199 HU, which corresponded to highly solid components, were compared between recurrence and non-recurrence. Furthermore, these radiological values were compared to pathological invasive volume (PIV). During this time, 709 patients had their lung cancer completely removed. From this cohort, 90 patients with pathological stage I solid lung adenocarcinoma were selected. In addition, recurrence was found in 26 patients (28.9%). Although two-dimensional axial image, serum carcinoembryonic antigen (CEA) level, and SUVmax on 18F fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) did not differ statistically between recurrent and non-recurrent patients, three-dimensional tumor and solid tumor volume did. Multivariate analysis indicated that three-dimensional solid tumor volume [hazard ratio: 2.440; 95% confidence interval (CI): 1.110-5.361, P=0.026] and epidermal growth factor receptor (EGFR) mutation (hazard ratio: 4.307; 95% CI: 1.328-13.977, P=0.015) were significantly associated with disease-free survival (DFS). When three-dimensional tumor and solid tumor volume were compared to PIV, three-dimensional solid tumor volume (3,091 mm3 on average) showed a highly similar value with PIV (2,930 mm3 on average), whereas three-dimensional tumor volume (6,175 mm3 on average) was significantly larger than PIV (P<0.001). In patients with early-stage solid lung adenocarcinoma, the measurement of three-dimensional solid tumor volume, which is correlated with PIV, accurately predicted the postoperative outcome.

ОЦЕНКА ВЕРХНИХ ДЫХАТЕЛЬНЫХ ПУТЕЙ И ОКРУЖАЮЩИХ МЯГКИХ ТКАНЕЙ У ПАЦИЕНТОВ С АНОМАЛИЯМИ ОККЛЮЗИИ В САГИТТАЛЬНОЙ ПЛОСКОСТИ ПО ДАННЫМ КОНУСНО-ЛУЧЕВОЙ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ

The relationship between facial morphology and upper airway (UA) dimensions is well established in scientific literature. Due to that, upper airway assessment is an important step of orthodontic treatment planning and diagnosis. Three-dimensional cone-beam computer tomography analysis (CBCT) of upper airway is simple and readily available method of measuring linear and angular parameters, cross-sectional area, and volume of the UA. &#x0D; The aim of the study is to measure the UA and surrounding tissue dimensions in patients with different types of sagittal malocclusion. 63 CBCT scans of adult patients without history of trauma, orthodontic treatment and congenital syndromes, diagnosed with distal, mesial, and normal occlusion have been studied using Materialise Mimics 21.0. Three-dimensional models of UA were created, and measurements of volume and cross-sectional area were taken using centerline and conventional cephalometric analysis. Non-parametric statistical correlational analysis was conducted.&#x0D; There were statistically significant differences between patients with mesial and distal occlusion. Moderate statistically significant correlations between facial morphology and UA dimensions have been found. In patients with distal occlusion, extended head position, posterior position of the hyoid bone, transverse maxillary and mandibular deficiency UA tend to have smaller size. The most predictive factor for minimal cross-sectional area of UA is the craniocervical angle and the distance between mandibular condyles.

Melon and rostral muscle morphology of Gervais' beaked whale (Mesoplodon europaeus): Alternating patterns of bilateral asymmetry.

Toothed whales utilize specialized nasal structures such as the lipid-rich melon to produce sound and propagate it into the aquatic environment. Very little nasal morphology of mesoplodont beaked whales has been described in the literature, and the anatomy of the melon and associated musculature of Gervais' beaked whale (Mesoplodon europaeus) remains undescribed. Heads of three (n = 3) Gervais' beaked whales were examined in detail via dissection as well as computed tomography (CT) and magnetic resonance imaging (MRI). Two additional Gervais' beaked whale individuals (n = 2) were studied via archived CT and MRI scans. Representative transverse dissection sections of the melon were processed for polarized light imaging to verify the presence of tendons inserting into the melon tissue. Three-dimensional (3D) CT reconstructions of the melon, rostral muscles, and associated structures were performed to assess morphology and spatial relationships. In all individuals, the melon's main body demonstrated a bilaterally asymmetrical, curvilinear geometry. This curvilinear shape was defined by a pattern of alternating asymmetry in the medial rostral muscles that projected into the melon's tissue. In transverse polarized light imaging, a network of tendons originating from these asymmetrical rostral muscle projections was observed permeating the melon's lipid tissue. This curvilinear melon morphology and associated asymmetrical musculature suggest a means of lengthening the lipid pathway within a relatively short dimensional footprint. In addition, the species-specific arrangement of muscular projections suggests complex fine-tuning of the melon's geometry during echolocation. Further studies may lend additional insight into the function of this unusual melon morphology.

Does preoperative 3D CT planning helps in predicting the component size determination and alignment in automatic robotic total knee arthroplasty (RA-TKA)

PurposeImage-based Robotic Total knee Arthroplasty (RA-TKA)was developed with the purpose of enhancing the accuracy in determining the component sizes preoperatively and helping surgeons in minimizing errors and improve patient outcomes. The research aims to find the reliability of robotic-assisted TKR based on images in determining the correct component sizes using preoperative three-dimensional (3D) computer tomography. MethodAfter ethical approval, we conducted a prospective study from March 2022 to December 2022. A total of 100 knees underwent image-based RA-TKA having grade 4 Osteoarthritis knee (Kellegren Lawrence classification). A single senior surgeon performed on all patients. Postoperative implant sizes and fit were assessed by five radiographic markers by an independent observer. ResultsIn our study, we found the mean age was (64.96 ± 7.3) years, with female to male ratio of 43:22. The preoperative 3D CT accuracy is 100% for femoral component sizing and 97% for the tibial component. There was a statistically significant improvement in varus deformity from preoperative 7.370 ± 3.70° to 1.24 0 ± 0.910° after surgery., p = 0.001. Improvement in flexion deformity correction was from preoperative 6.50 ± 6.30 to postoperative 1.640 ± 1.770, p = 0.001. ConclusionOur study concludes that the use of pre-operative 3D CT helps in predicting the component sizes, minimizes surgical time, and enhances implant position accuracy, as well as improves postoperative limb alignment in the coronal and sagittal planes.

Does Preoperative Modic Changes Influence the Short-term Fusion Rate of Single Level Transforaminal Lumbar Interbody Fusion?-a Matched-pair Case Control Study.

At present, the influence of Modic changes (MCs) on postoperative fusion rate of lumbar interbody fusion (LIF) is mainly focused on the medium- and long-term fusion rate, while the short-term fusion rate has not been reported. The aim of this study was to compare the short-term fusion rate of lumbar degenerative disease patients with and without MCs after single level transforaminal lumbar interbody fusion (TLIF). In this retrospective and matched-pair case control study, we included 100 patients who underwent TLIF from January 2017 to January 2020 and had at least two follow-up visits over a two-year period. Fifty patients with MCs (MCs group) were matched with 50 patients without MCs (non MCs group) for age, sex, surgical level, diagnosis, operative time, and intraoperative blood loss. We collected the X-ray and computed tomography (CT) data of patients from 3 months to 2 years after the operation to assess bony fusion and the cage union ratio. According to the type of cage, the MCs group was further divided into the nano-hydroxyapatite/polyamide 66 (n-HA/PA66) group and polyetheretherketone (PEEK) group, and the fusion performance between the two groups was compared. Finally, age, sex, body mass index (BMI), smoking and cage type were included in the logistic regression model for risk factor analysis. The bony fusion rates in the MCs group at 3 months, 6 months, 1 year and 2 years after surgery were significantly lower than those in the non MCs group (P < 0.05) (23.8% vs 62.5%, 52.6% vs 78.9%, 61.1% vs 83.3%, 74.0% vs 90.0%). The average coronal cage union ratios of the upper and lower endplates in the MCs group were significantly lower than those in the non MCs group (54.3% ± 17.5% vs 75.0% ± 17.2%, P < 0.05; 73.3% ± 12.0% vs 84.9% ± 8.0%, P < 0.05). Similarly, analogous results were obtained by comparing the MCs and non MCs groups' three-dimensional CT sagittal plane images (62.5% ± 16.5% vs 76.1% ± 12.4%, P < 0.05; 67.0% ± 13.9% vs 79.8% ± 11.5%, P < 0.05). Short-term fusion rates were lower in the MCs group than in the non MCs group. The coronal and sagittal cage union ratio in the MCs group was lower than that in the non MCs group. The fusion performance of n-HA/PA66 and PEEK cages in the MCs group was comparable.