Improving the robustness of radiomic features to patient size variations in CBCT imaging for radiotherapy.

Postural changes influence systemic hemodynamics and may affect cerebral perfusion; however, quantitative evaluation remains limited in vivo under physiological gravitational conditions. We aimed to assess posture-dependent alterations in cerebral perfusion using upright multidetector computed tomography perfusion (CTP), with whole-brain cerebral blood flow (CBF) as the primary outcome. This was a single-center observational study of healthy volunteers approved by the institutional review board. Eighteen volunteers underwent CTP imaging in both the supine and seated positions on the same day using two 320-row multidetector CT scanners with identical systems. Whole-brain CBF was defined as the primary endpoint. Mean transit time (MTT) and cerebral blood volume (CBV) were evaluated as secondary outcomes. Paired comparisons were performed between postures, and exploratory analyses assessed regional changes and interindividual variability. Whole-brain CTP-derived CBF was significantly higher in the seated position than in the supine position (32.9 ± 6.0 [mean ± standard deviation] versus 29.2 ± 5.6 mL/100 g/min; p = 0.010), representing a 1.15 ± 0.19-fold increase. CTP-derived MTT was significantly shorter in the seated position (4.25 ± 0.61 versus 4.63 ± 0.72 s; p = 0.035), and CTP-derived CBV showed a modest but significant increase (2.23 ± 0.16 versus 2.16 ± 0.17 mL/100 g; p = 0.044). Regional perfusion changes were consistent across brain segments with interindividual variability in postural responses. Upright CTP detected posture-associated differences in whole-brain CTP-derived perfusion metrics, suggesting potential utility for investigating physiological and pathological alterations in cerebral hemodynamics associated with postural change. Upright CTP enables physiological evaluation of posture-related cerebral hemodynamics under gravitational loading and may provide new insights into cerebral circulation in both health and disease. Whole-brain cerebral blood flow increased by 15% in the seated position compared with supine using upright CT perfusion. Mean transit time shortened by 7% and cerebral blood volume increased modestly by 4% in the seated position. Perfusion responses showed marked interindividual variability, suggesting different physiological adaptations to posture.

Cholesteatoma is a locally destructive lesion of the temporal bone characterized by progressive bone erosion and potential extracranial and intracranial complications. High-resolution computed tomography (HRCT) plays a crucial role in early detection and preoperative assessment. To evaluate the diagnostic performance of HRCT in detecting cholesteatoma and its complications through correlation with intraoperative findings. This prospective observational study included 77 patients with clinically suspected cholesteatoma over 18 months. HRCT of the temporal bone was performed using a 32-slice multidetector CT scanner with thin-section (0.6-1 mm) bone algorithm reconstruction. Parameters assessed included soft tissue presence, scutum erosion, ossicular erosion, mastoid involvement, tegmen tympani erosion, sigmoid plate erosion, facial canal erosion, lateral semicircular canal fistula, and sinus tympani involvement. Surgical findings served as the reference standard, and diagnostic performance was calculated. The mean age was 40.64 ± 16.28 years, with peak incidence in the 21-40-year group. Conductive hearing loss (57.1%) and ear discharge (32.5%) were common presentations. HRCT demonstrated excellent concordance with surgery for scutum erosion (98.7%), ossicular erosion (97.4%), and facial canal erosion (100%). Sensitivity ranged from 68% (sinus tympani involvement) to 100% (scutum and facial canal erosion), while specificity was 90.9%-100%. Overall diagnostic accuracy ranged from 89.6% to 100%. Histopathology confirmed cholesteatoma in 94.8% of cases. HRCT of the temporal bone demonstrates high diagnostic accuracy and strong surgical correlation in cholesteatoma evaluation, supporting its role as a reliable preoperative imaging modality for early detection and complication assessment.

Cervical Spine Clearance in Adult and Pediatric Trauma: A Systematic Review.

Accurate age estimation significantly influences legal outcomes in several contexts. The sternum is one of the most important landmarks that identify age. This cross-sectional study aims to propose Sternum Maturation Models for age estimation, recruiting 247 Egyptian subjects who underwent chest Multidetector Computed Tomography (MDCT) imaging. The maturation of the manubriosternal joint (MSJ), the xiphisternal joint (XSJ), and the junctions between the four sternebrae (S1, S2, and S3) were investigated through a three-element fusion staging. MS-XS Score, an S1-S3 Score, an Overall Score, and an Overall Score excluding the MSJ were calculated. Despite the observed variability, 97% of females reached full sternal fusion by approximately 67 years, whereas males reached this stage a decade later. The ages of fusion initiation and termination were earlier in females, whereas males showed stronger correlations between age and all scores (rho values ranging from 0.552 to 0.750). For all individuals, including those aged ≤ 25 years, the Overall Score excluding the MSJ was the best age predictor, followed by the Overall Score. Above 25 years, the Overall Score excluding MSJ was the best age predictor, followed by the MS-XS Score. The Overall Scores, excluding and including the MSJ, ≥ 6, exhibited high accuracy in predicting ages ≥ 18 and 21 years in males (AUC ≥ 0.973) and substantial agreement with actual ages (kappa coefficients ≥ 0.840). Meanwhile, the performance of both models declined in older ages above 40 years, and in females. The MDCT-based Sternal Maturation Models are reliable, non-invasive approaches for forensic age estimation.

Purpose To quantify lung and lobar volumes superimposed on the mediastinum and diaphragm on upright chest radiographs using upright multidetector row CT and to compare them with supine measurements. Materials and Methods In this prospective study, asymptomatic Asian participants underwent both upright and supine multidetector row CT within 2 hours. Lung and lobar volumes were measured in each position. Ray-sum images were reconstructed to delineate mediastinal and diaphragmatic boundaries, and superimposed volumes in the posteroanterior direction were calculated. These CT-derived volumes were considered to approximate lung fields projected over the mediastinum and diaphragm on radiographs. Percentages of superimposed volumes relative to total lung and lobar volumes were determined. Mixed-effects models and multiple linear regression analyses were used. Results The study included 132 participants (mean age ± SD, 47.4 years ± 11.4; 85 female; mean body mass index ± SD, 22.2 ± 3.4 [calculated by dividing weight in kilograms by height in meters squared]). The proportion of lung volume superimposed on the mediastinum and diaphragm was 23.9% ± 3.1 in the upright position, significantly lower than 25.7% ± 3.3 in the supine position (P < .001), despite a 9.8% increase in total lung volume upright. Superimposed percentages of the right upper, middle, and lower lobes and the left upper and lower lobes in the upright position were 10.4% ± 2.5, 7.5% ± 3.2, 28.8% ± 7.9, 12.3% ± 1.9, and 46.0% ± 8.3, respectively. All lobes except the left lower lobe showed significantly lower superimposition upright than supine (all P < .03). Multiple linear regression identified older age, higher body mass index, and male sex as independent predictors of greater superimposition in the upright position (all P < .03). Conclusion Lung volume superimposed on the mediastinum and diaphragm was lower on upright than supine chest radiographs despite greater lung volume in the upright position. University Hospital Medical Information Network Clinical Trials Registry: UMIN000026586 Keywords: CT, Thorax, Lung, Mediastinum, Diaphragm, Anatomy, Comparative Studies, Technology Assessment Supplemental material is available for this article. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license.

Primary pulmonary artery sarcoma (PPAS) is a mesenchymal tumor originating from the pulmonary artery, accounting for approximately 0.001–0.003% of all sarcomas. The early clinical symptoms are atypical, and diagnosis is often delayed, making the management of this disease challenging. The widespread availability of multidetector computed tomography (MDCT), 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), and high-resolution echocardiography has significantly improved the diagnostic capability for PPAS. We herein report a 74-year-old female patient who presented with a 3-week history of exertional dyspnea without an apparent trigger. She had received anti-inflammatory therapy at another hospital for one week. Five days before admission, she experienced right-sided chest pain without apparent cause, which was respiratory-related. On the day of admission, laboratory tests revealed a slight elevation in D-dimer levels. Echocardiography showed an irregular, moderately echogenic mass at the origin of the right pulmonary artery. Enhanced computed tomography (CT) of the chest revealed a filling defect in the right pulmonary artery accompanied by bilateral pleural effusion. The patient was given heparin anticoagulation therapy. To confirm the nature of these lesions, a PET/CT scan was conducted five days after admission, which indicated hypermetabolism in the right pulmonary artery, suggesting primary pulmonary artery sarcoma. Due to the poor efficacy of anticoagulation therapy, the patient continued to experience breath-holding after physical activity. Subsequently, catheter-guided interventional angiography was carried out for pulmonary artery thrombectomy and biopsy, and histopathological examination revealed pulmonary artery sarcoma. Given the patient’s respiratory failure and heart failure, as well as the uncertain efficacy of radiotherapy and chemotherapy, interventional pulmonary artery thrombectomy alleviated the chest pain. Currently, the patient’s overall condition is stable.

The thymic veins are small vessels located in the anterior superior mediastinum, and thymic tissue undergoes physiological degeneration with age. Multidetector computed tomography (MDCT) with isotropic resolution allows comprehensive visualization of small mediastinal vessels. However, large-sample studies describing normal thymic veins using contrast-enhanced MDCT remain lacking. This study aimed to evaluate the morphologic features of normal thymic veins on venous-phase enhanced MDCT and to analyze their distribution patterns according to age group, gender, and laterality in a large patient cohort. The enhanced MDCT images of the chest were retrospectively collected from 289 cases. First, the collected cases were divided into four age groups; second, the thymic veins shown in the venous phase were classified and measured by three-dimensional visualization using MPR and VR techniques; lastly, statistical analysis was performed to analyze the relationship between the occurrence rate of the different types of thymic veins and age groups, genders as well as the relationships between the inner diameter and sides. The inter-observer agreement was statistically analyzed. The manifestations of the thymic vein could be divided into three types by enhanced MDCT. The thymic vein drained upward into the inferior thyroid vein and the left brachiocephalic vein. The occurrence rate of the continuous, the intermittent, the unrecognized types were 63.0%, 21.8%, and 15.2%, respectively. 9.3% was the incidence rate of the intermediate vein among the continuous type. The display rates of the continuous, the intermittent, and the unrecognized in the four age groups (0-20), (20-40), (40-60), and >60 years old) were 8.3%, 0.0%, 91.7%;71.1%, 5.3%, 23.7%;61.4%, 35.6%, 3.0%; and 72.7%, 26.1%, 1.1%, respectively. Statistically significant difference between the occurrence rate of different types and age groups was proved by the Chi-squared test (P<0.001). No significant difference between the occurrence rate of different types and genders by the Chi-squared test (P=0.07). The range of diameters of the continuous type of left, right thymic veins was (1.90 ± 0.52 mm,2.04 ± 0.6 mm), respectively, and the diameter of the right was larger than the left by t-test. Both the occurrence rates of the continuous and those of the intermittent increased with age in the line graph, while the occurrence rates of the unrecognized type decreased with age. High agreements were demonstrated by the intra-class correlation coefficient. Thymic veins show characteristic morphological changes with advancing age, likely related to the physiological involution of the thymus gland. Young individuals demonstrate very low visualization rates, whereas older age groups show predominantly continuous or intermittent visualization. MDCT with three-dimensional reconstruction enables reliable depiction and classification of normal thymic veins, which may serve as an anatomical reference for mediastinal imaging interpretation. Most thymic veins still existed despite the degeneration of the thymus in a large-sample MDCT study. A variety of drainage pathways into the inferior thyroid vein and left brachiocephalic vein were displayed, and the occurrence rate of different venous drainage patterns varied with age. Preoperative assessment of the thymic veins would help reduce intraoperative bleeding in the anterior superior mediastinum.

Multidetector computed tomography (MDCT) enables high-resolution multiplanar and 3D reconstructions in thoracic imaging. However, conventional 3D reconstruction methods are computationally expensive, time-consuming, and require specialized expertise. This short communication introduces a novel algorithm (HGM) based on vector graphics and RGB-to-HSI (hue, saturation, intensity) color-space transformation, designed to provide a low-cost, high-precision tool for visualization and classification of intrathoracic lesions. Chest CT DICOM datasets were processed using the HGM algorithm, developed in collaboration with visual-effects engineers. The pipeline incorporated RGB-to-HSI conversion, vector-graphics-based modeling, and scripted segmentation for automated isolation of thoracic organs and lesions. Reconstructions were rendered into an interactive format compatible with Adobe Animate®. Pilot testing in a 41-year-old woman with an intrapulmonary teratoma demonstrated accurate 3D reconstruction for preoperative planning. Tumor dimensions were 14×12×10.3 cm, closely matching radiologic measurements (14×12×10 cm). The mean processing time was 15 minutes per dataset using modest computational resources (~US $1,600 workstation) and minimal training (~4 hours). The HGM algorithm enabled rapid anatomical segmentation, real-time 3D manipulation, and dynamic visualization from multiple perspectives, offering an alternative to conventional 3D CT reconstruction methods. RGB-to-HSI transformation provides low-cost, high-precision 3D images of intrathoracic lesions. Future directions will focus on validating the algorithm by testing its performance in different tumors, post-surgical follow-up, radiotherapy planning, and other applications.

Multidetector CT has improved the detection, diagnosis, and characterization of gastric malignancies, and as well as the evaluation of distant metastases. Gastric malignancies range from common types such as adenocarcinoma, lymphoma, and GISTs to rare types such as neuroendocrine tumors, liposarcoma, leiomyosarcoma, plasmacytoma, and metastases from other cancers. CT is often the preferred modality for their assessment. These tumors can appear as a single lesion, multifocal involvement, or diffuse wall thickening, and they often have overlapping imaging features, making diagnosis challenging. This pictorial review presents the CT findings of these malignancies to help radiologists understand the differential diagnosis, recognize early CT patterns, and guide appropriate management.

Gallstones (cholelithiasis) are common, with a significant portion of affected individuals developing acute cholecystitis, which can lead to severe complications. While ultrasound (US) is typically the first imaging method used, multidetector computed tomography (MDCT) may be better at detecting more complex scenarios. This study aimed to compare the detection of imaging features and complications of acute cholecystitis between US and MDCT in a cohort of confirmed cases, and to evaluate their complementary roles in clinical practice. A retrospective study was conducted including 134 adults with clinically suspected acute cholecystitis who underwent same-day US and MDCT, with subsequent confirmation by pathology or intervention. Two radiologists independently reviewed all imaging studies, and the detection of imaging features and complications was compared. US showed significantly higher detection rates than MDCT for gallbladder wall thickening (98.5% vs. 66.4%, P < 0.001), sludge (35.1% vs. 14.9%, P < 0.001), and pericholecystic fluid (75.4% vs. 47.8%, P < 0.001). Conversely, MDCT more frequently identified complications such as choledocholithiasis (8.2% vs. 2.2% by US, P = 0.041) and liver abscesses (6.7% vs. 1.5% by US, P = 0.035). MDCT also identified findings consistent with cholecystitis in 7 patients (5.2%) not detected by US and was associated with a change in management of 20 patients (14.9%). US remains effective as a first-line modality for detecting acute cholecystitis, while MDCT offers additional value in identifying complications and influencing management. Together, these findings support a complementary, rather than substitutive, role for the two modalities.

Abstract Background and aims Rapid exclusion of intracranial hemorrhage is critical in acute stroke care. Whether syngo DynaCT Sine Spin non-contrast flat detector CT (FDCT) is sufficient to rule out intracranial hemorrhage compared with conventional multidetector CT (MDCT) remains unknown. Methods SPINNERS is a multicenter, international, prospective, cross-sectional, endpoint assessor–blinded, non-inferiority trial. Patients presenting within 24 hours of last seen well with severe stroke symptoms (NIHSS &amp;gt;7) or symptoms suggestive of intracranial hemorrhage were eligible. MDCT and FDCT were performed within a maximum interval of 4 hours without intervening invasive procedures. The primary endpoint was presence of intracranial hemorrhage (yes/no). Sensitivity and specificity of FDCT were calculated using MDCT as ground truth. FDCT images were independently rated by six blinded readers in a core laboratory. Non-inferiority was predefined as the lower bound of the 95% confidence interval for sensitivity and specificity exceeding 95%. Results Between October 2022 and November 2024, 252 patients were enrolled across 13 centers in Europe and the United States (126 female; 126 ischemic stroke, 126 hemorrhagic stroke, including 14 isolated infratentorial hemorrhages). Median age was 73 years (IQR 61–81.5), and median NIHSS at admission was 13 (IQR 7–18). Final analyses of diagnostic performance are ongoing and will be presented at ESOC 2026. Conclusions SPINNERS will inform physicians whether non-contrast FDCT is sufficient for excluding intracranial hemorrhage in patients with suspected severe acute stroke. ClinicalTrials.gov Identifier: NCT05458908 Conflict of interest

Cone beam computed tomography (CBCT) provides morphological details of the dental hard tissues and bone. However, the relationship between object density and CBCT grey values is unreliable and limits application of CBCT for quantitative evaluation of bone density. This single center, open-label clinical trial investigated the validity of novel dual-energy CBCT device (DE-CBCT) to assess jaw bone density. The study analyses comprised 24 subjects who were examined with DE-CBCT and multidetector CT (MDCT)-an established standard for bone density assessment. MDCT and DE-CBCT scans of each subject were analyzed in the vendor's software application for assessment of bone density at 10 discrete sites in the jaws. Two independent assessments were made. The mean bone density assessed by DE-CBCT and MDCT were not significantly different (0.46 ± 0.36g/cc versus 0.48 ± 0.31g/cc, respectively). Bone density assessments from DE-CBCT correlated well with MDCT assessments (Pearson's correlation r = 0.92, p < 0.0001). Bland-Altman analyses demonstrated higher agreement between the two techniques at densities great than 0.6g/cm3. However, at lower densities the limits of agreement were broad. DE-CBCT is a promising approach to assess bone density in the jaw bones. The investigational device performs best in well-trabeculated and cortical bone, with reduced reliability in sparsely trabeculated regions. Future refinements in this technology will be needed to expand the range of reliability for reliable assessment of bone density. The study is registered in clinical trials.gov, NCT04686084.

Radiation exposure remains a major concern in dentomaxillofacial imaging, especially for children and young adults who require repeated examinations. A precise, non-ionizing alternative for craniofacial measurement would have significant implications for clinical practice. Computed tomography (CT) and cephalometry are widely used but expose patients to ionizing radiation. Zero Echo Time Magnetic Resonance Imaging (ZTE-MRI) enables visualization of short-T2 tissues, including cortical bone, without radiation by minimizing TE towards zero; however, clinical head-and-neck use has been limited. The goal of the present study was to investigate the possibility of performing precise 3D measurements of the craniofacial regions using ZTE-MRI. Twenty-nine participants (mean age 32.14 ± 17.09 years; 23 female, 6 male) underwent MDCT and ZTE-MRI. Standard cephalometric landmarks were identified, yielding 27 linear and 21 angular variables. For each variable, linear regression analysis was performed for the results on MDCT (Multi-Detector CT) images and ZTE-MRI. Nineteen linear and eight angular variables had regression coefficients between 0.9 and 1.1, and 28 of the linear and 16 of the angular variables had R2 values of 0.81 or higher. Twenty-five linear and 16 angular variables showed Cohen's effect sizes within the ±0.8 range. Variables derived from skeletal reference points showed clinically acceptable results, indicating that ZTE-MRI is useful for these measurements. In contrast, variables involving dental reference points demonstrated lower agreement, making accurate measurement in these regions difficult. To our knowledge, this study is the first to show that ZTE-MRI allows feasible linear and angular craniofacial measurements used in dental practice and demonstrates good agreement with MDCT for major skeletal landmarks. These findings support its potential future clinical applicability for radiation-free bone assessment; however, further research is warranted to establish its performance across all measurements.

Celiac axis stenosis (CAS) is a significant vascular condition in patients undergoing pancreatoduodenectomy due to division of the celiac circulation during the procedure. However, the reliable conditions for when to intervene remain undefined. We retrospectively analyzed 1,042 consecutive patients who underwent pancreatoduodenectomy. The stenosis diameter and maximum diameter of the celiac axis were measured on preoperative multidetector CT to calculate the stenosis rate (SR). In the patients with CAS (SR ≥ 50%), two additional CT-based markers of arcade development were quantified: 1) the gastroduodenal-to-common hepatic artery diameter (GDA/CHA) ratio and 2) the diameter of the collateral artery connecting the GDA and inferior pancreatoduodenal artery. Four factors (stenosis diameter ≤2mm, SR ≥70%, GDA/CHA ratio ≥1.0, collateral artery diameter ≥3mm) were assessed as predictors of intraoperative intervention. Eighty-five patients (8.2%) had CAS (SR ≥50%), of which only 11 (1.1% of the entire cohort) required intervention: median arcuate ligament division (n = 4), arterial reconstruction (n = 5), or collateral preservation (n = 2). Each of the four factors (stenosis diameter ≤2mm, SR ≥70%, GDA/CHA ratio ≥1.0, collateral artery diameter ≥3mm) was associated with the need for intervention. Intervention for CAS was not required in any case in which none of the four factors were present. In contrast, all patients with three or more positive factors required intervention. The four factors (stenosis diameter, SR, GDA/CHA ratio, and collateral artery diameter) may serve as important predictors of CAS intervention. Incorporating these factors into preoperative planning enables surgeons to prepare necessary resources.

Acute Mesenteric Ischemia.

Indeterminate focal liver lesions (FLLs) detected through ultrasonography or single-phase imaging present a diagnostic challenge due to their varied management depending on whether they are benign or malignant. Therefore, it is of interest to evaluate the diagnostic performance of triple-phase multidetector computed tomography (MDCT) in characterizing these lesions by assessing dynamic contrast enhancement across arterial, portal venous and delayed phases. Results showed that triple-phase CT accurately differentiated benign from malignant lesions, with vascular and enhancement patterns providing key diagnostic insights. Malignant lesions exhibited distinct features, including portal venous hypoenhancement and late-phase washout. Thus, we show the high accuracy of triple-phase CT for managing indeterminate FLLs, supporting better clinical decision-making.

Application of upright multidetector CT in orthopedics and the musculoskeletal system: insights into anatomy, alignment, and biomechanics.

This study is based on American Association of Physicist in Medicine (AAPM) task group (TG) report 204 to compare the displayed and calculated Radiation dose imparted to the patient in computed tomography (CT) head examination and the effective dose. To identify whether there is a difference between displayed radiation doses and size-specific dose in CT head imaging. For ruling out the possibility of dose estimation difference. A prospective cross-sectional study was done on CT head examinations using multidetector CT. The study included subjects aged between 18 and 60 years with no obvious morphological head deformities. We compared the size-specific dose estimate (SSDE) displayed and calculated where we used f factor for effective diameter from AAPM report 204 and manually calculated the SSDE for comparison. We also calculated the effective dose for head CT manually using dose-length product and k value from AAPM report 96. The difference between SSDE Calculated and displayed was found to be -11.99%, the negative value depicts that the SSDE displayed in the patient dose chart in CT is much lower than the calculated SSDE. Hence it highly underestimates the dose received by the patient and further cancer risk estimation. We also found that the radiation dose received by patient is inversely related to the effective diameter of their head. The observed difference between the calculated and displayed dose values falls within the acceptable range of 10%-20% as recommended by the AAPM TG report 204, indicating consistency with established guidelines.

Determination of a safe radiation distance from a 16-slice multi-detector computed tomography (MDCT) scan machine.