Combined conventional factors and the radiomics signature of coronary plaque texture could improve cardiac risk prediction.

OBJECTIVES: This study aims to investigate how radiomics analysis can help understand the association between plaque texture, epicardial adipose tissue (EAT), and cardiovascular risk. Working with a Photon-counting CT, which exhibits enhanced feature stability, offers the potential to advance radiomics analysis and enable its integration into clinical routines. METHODS: Coronary plaques were manually segmented in this retrospective, single-centre study and radiomic features were extracted using pyradiomics. The study population was divided into groups according to the presence of high-risk plaques (HRP), plaques with at least 50% stenosis, plaques with at least 70% stenosis, or triple-vessel disease. A combined group with patients exhibiting at least one of these risk factors was formed. Random forest feature selection identified differentiating features for the groups. EAT thickness and density were measured and compared with feature selection results. RESULTS: A total number of 306 plaques from 61 patients (mean age 61 years +/- 8.85 [standard deviation], 13 female) were analysed. Plaques of patients with HRP features or relevant stenosis demonstrated a higher presence of texture heterogeneity through various radiomics features compared to patients with only an intermediate stenosis degree. While EAT thickness did not significantly differ, affected patients showed significantly higher mean densities in the 50%, HRP, and combined groups, and insignificantly higher densities in the 70% and triple-vessel groups. CONCLUSION: The combination of a higher EAT density and a more heterogeneous plaque texture might offer an additional tool in identifying patients with an elevated risk of cardiovascular events. CLINICAL RELEVANCE STATEMENT: Cardiovascular disease is the leading cause of mortality globally. Plaque composition and changes in the EAT are connected to cardiac risk. A better understanding of the interrelation of these risk indicators can lead to improved cardiac risk prediction. KEY POINTS: Cardiac plaque composition and changes in the EAT are connected to cardiac risk. Higher EAT density and more heterogeneous plaque texture are related to traditional risk indicators. Radiomics texture analysis conducted on PCCT scans can help identify patients with elevated cardiac risk.

Light chain mutations contribute to defining the fibril morphology in systemic AL amyloidosis.

Systemic AL amyloidosis is one of the most frequently diagnosed forms of systemic amyloidosis. It arises from mutational changes in immunoglobulin light chains. To explore whether these mutations may affect the structure of the formed fibrils, we determine and compare the fibril structures from several patients with cardiac AL amyloidosis. All patients are affected by light chains that contain an IGLV3-19 gene segment, and the deposited fibrils differ by the mutations within this common germ line background. Using cryo-electron microscopy, we here find different fibril structures in each patient. These data establish that the mutations of amyloidogenic light chains contribute to defining the fibril architecture and hence the structure of the pathogenic agent.

Virtual Non-Contrast versus True Native in Photon-Counting CT: Stability of Density of Upper Abdominal Organs and Vessels.

The clinical use of photon-counting CT (PCCT) allows for the generation of virtual non-contrast (VNC) series from contrast-enhanced images. In routine clinical practice, specific issues such as ruling out acute bleeding require non-contrast images. The aim of this study is to evaluate the use of PCCT-derived VNC reconstructions in abdominal imaging. PCCT scans of 17 patients including early arterial, portal venous and native sequences were enrolled. VNC reconstructions have been calculated. In every sequence and VNC reconstruction, 10 ROIs were measured (portal vein, descending aorta, inferior vena cava, liver parenchyma, spleen parenchyma, erector spinae muscle, subcutaneous adipose tissue, first lumbar vertebral body, air, and psoas muscle) and density values were compared. The VNC reconstructions show significant changes in density compared to the contrast-enhanced images. However, there were no significant differences present between the true non-contrast (TNC) and any VNC reconstructions in the observed organs and vessels. Significant differences (p < 0.05) between the measured mean density values in the TNC versus VNC reconstructions were found in fat and bone tissue. The PCCT-derived VNC reconstructions seemed to be comparable to the TNC images, despite some deviations shown in the adipose tissue and bone structures. However, the further benefits in terms of specific clinical issues need to be evaluated.

Eculizumab for Shiga-toxin-induced hemolytic uremic syndrome in adults with neurological involvement.

The role of eculizumab in treating Shiga-toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome (HUS) patients with neurological involvement remains unclear. We describe two distinctly different STEC-HUS patients with neurologic involvement successfully managed with eculizumab, and perform a literature review of all published cases. Both patients had complete resolution of neurological symptoms after initiation of eculizumab. Eighty patients with STEC-HUS treated with eculizumab were identified in the literature, 68.7% had complete resolution of neurological symptoms. Based on our experience and literature review, three prevailing themes were noted: 1) Early eculizumab administration optimized neurological outcomes, 2) Symptom resolution may not be immediate, neurological symptoms may initially worsen before improvement, and 3) Plasma exchange yielded no benefit. Early administration of eculizumab may reverse neurotoxicity in patients with STEC-HUS.

Streamlining Acute Abdominal Aortic Dissection Management-An AI-based CT Imaging Workflow.

Life-threatening acute aortic dissection (AD) demands timely diagnosis for effective intervention. To streamline intrahospital workflows, automated detection of AD in abdominal computed tomography (CT) scans seems useful to assist humans. We aimed at creating a robust convolutional neural network (CNN)-based pipeline capable of real-time screening for signs of abdominal AD in CT. In this retrospective study, abdominal CT data from AD patients presenting with AD and from non-AD patients were collected (n 195, AD cases 94, mean age 65.9 years, female ratio 35.8%). A CNN-based algorithm was developed with the goal of enabling a robust, automated, and highly sensitive detection of abdominal AD. Two sets from internal (n = 32, AD cases 16) and external sources (n = 1189, AD cases 100) were procured for validation. The abdominal region was extracted, followed by the automatic isolation of the aorta region of interest (ROI) and highlighting of the membrane via edge extraction, followed by classification of the aortic ROI as dissected/healthy. A fivefold cross-validation was employed on the internal set, and an ensemble of the 5 trained models was used to predict the internal and external validation set. Evaluation metrics included receiver operating characteristic curve (AUC) and balanced accuracy. The AUC, balanced accuracy, and sensitivity scores of the internal dataset were 0.932 (CI 0.891-0.963), 0.860, and 0.885, respectively. For the internal validation dataset, the AUC, balanced accuracy, and sensitivity scores were 0.887 (CI 0.732-0.988), 0.781, and 0.875, respectively. Furthermore, for the external validation dataset, AUC, balanced accuracy, and sensitivity scores were 0.993 (CI 0.918-0.994), 0.933, and 1.000, respectively. The proposed automated pipeline could assist humans in expediting acute aortic dissection management when integrated into clinical workflows.

Comparing quantitative image parameters between animal and clinical CT-scanners: a translational phantom study analysis.

Purpose: This study compares phantom-based variability of extracted radiomics features from scans on a photon counting CT (PCCT) and an experimental animal PET/CT-scanner (Albira II) to investigate the potential of radiomics for translation from animal models to human scans. While oncological basic research in animal PET/CT has allowed an intrinsic comparison between PET and CT, but no 1:1 translation to a human CT scanner due to resolution and noise limitations, Radiomics as a statistical and thus scale-independent method can potentially close the critical gap. Methods: Two phantoms were scanned on a PCCT and animal PET/CT-scanner with different scan parameters and then the radiomics parameters were extracted. A Principal Component Analysis (PCA) was conducted. To overcome the limitation of a small dataset, a data augmentation technique was applied. A Ridge Classifier was trained and a Feature Importance- and Cluster analysis was performed. Results: PCA and Cluster Analysis shows a clear differentiation between phantom types while emphasizing the comparability of both scanners. The Ridge Classifier exhibited a strong training performance with 93% accuracy, but faced challenges in generalization with a test accuracy of 62%. Conclusion: These results show that radiomics has great potential as a translational tool between animal models and human routine diagnostics, especially using the novel photon counting technique. This is another crucial step towards integration of radiomics analysis into clinical practice.

Future directions in haploidentical hematopoietic stem cell transplantation.

Outcomes of haploidentical hematopoietic stem cell transplantation (haplo-SCT) have improved over time. Graft failure and graft-versus-host disease (GVHD), which were important complications in major human leukocyte antigen (HLA)-disparity stem cell transplantation, have significantly decreased. These improvements have led to an exponential increase in the use of haploidentical donors for transplantation, as well as in the number of publications evaluating haplo-SCT outcomes. Many studies focused on factors important in donor selection, novel conditioning regimens or GVHD prophylaxis, the impact of donor-specific anti-HLA antibodies (DSA), as well as strategies to prevent disease relapse post-transplant. DSA represents an important limitation and multimodality desensitization protocols, including plasma exchange, rituximab, intravenous immunoglobulin and donor buffy coat infusion, can contribute to the successful engraftment in patients with high DSA levels and is currently the standard therapy for highly allosensitized individuals. With regards to donor selection, younger donors are preferred due to lower risk of complications and better transplant outcomes. Moreover, recent studies also showed that younger haploidentical donors may be a better choice than older-matched unrelated donors. Improvement of disease relapse remains a top priority, and several studies have demonstrated that higher natural killer (NK) cell numbers early post-transplant are associated with improved outcomes. Prospective studies have started to assess the role of NK cell administration in decreasing post-transplant relapse. These studies suggest that the incorporation of other cell products post-transplant, including the administration of chimeric antigen receptor T-cells, should be explored in the future.

Persistent Impairment in Immune Reconstitution and Worse Survival Outcomes in Allogeneic Stem Cell Transplantation Patients with Early Coronavirus Disease 2019 Infection.

Patients undergoing allogenic hematopoietic stem cell transplantation (HSCT) are at an increased risk of mortality due to transplantation-related complications in the first year post-transplantation, owing in part to the profound immune dysregulation with T cell and B cell lymphopenia and functional impairment. Although several large studies have reported higher mortality rates from Coronavirus disease 2019 (COVID-19) in HSCT recipients, to date no study has focused on the impact of early COVID-19 infection on immune reconstitution post-transplantation and the correlation with transplantation outcomes. We retrospectively analyzed 61 consecutive adult patients who underwent their first allogeneic HSCT at our institution. Thirteen patients (21.3%) experienced early COVID-19 infection, with a median time to diagnosis of 100 days post-transplantation. In multivariable analysis, patients with early COVID-19 infection had significantly worse overall survival (adjusted hazard ratio [aHR], 4.06; 95% confidence interval [CI], 1.26 to 13.05; P = .019) and progression-free survival (aHR, 6.68; 95% CI, 2.11 to 21.11; P = .001). This was attributed mainly to higher nonrelapse mortality (NRM) among early COVID-19 patients (P = .042). Allogeneic HSCT recipients with early COVID-19 infection had significant delays in absolute lymphocyte count (95% CI, -703.69 to -56.79; P = .021), CD3+CD4+ cell (95% CI, -105.35 to -11.59; P = .042), CD3+CD8+ cell (95% CI, -324.55 to -57.13; P = .038), and CD3-CD56+ cell (95% CI, -193.51 to -47.31; P = .014) recovery compared to those without early COVID-19 infection. Our findings suggest that patients with early COVID-19 infection after allogeneic HSCT have higher NRM and worse survival, at least in part due to impaired immune reconstitution post-transplantation.

Chronic sensory contact with subordinated conspecifics promotes splenic glucocorticoid resistance in experimentally wounded C57BL/6N male mice.

Chronic psychosocial stress induced by the chronic subordinate colony housing (CSC, 19 Days) paradigm promotes functional splenic in vitro glucocorticoid (GC) resistance, but only if associated with significant bite wounding or prior abdominal transmitter implantation. Moreover, sensory contact to social defeat of conspecifics represents a social stressor for the observer individual. As the occurence and severity of bite wounding is not adequately controllable, the present study aimed to develop an animal model, allowing a bite wound-independent, more reliable generation of chronically-stressed mice characterized by functional splenic in vitro GC resistance. Therefore, male C57BL/6N mice received a standardized sterile intraperitoneal (i.p.) incision surgery or SHAM treatment one week prior to 19-days of (i) CSC, (ii) witnessing social defeat during CSC exposure in sensory contact (SENS) or (iii) single-housing for control (SHC), before assessing basal and LPS-induced splenic in vitro cell viability and GC resistance. Our results indicate that individually-housed SENS but not CSC mice develop mild signs of splenic in vitro GC resistance, when undergoing prior i.p.-wounding. Taken together and considering that future studies are warranted, our findings support the hypothesis that the combination of repeated standardized i.p.-wounding with chronic sensory stress exposure represents an adequate tool to induce functional splenic in vitro GC resistance independent of the occurrence of uncontrollable bite wounds required in social stress paradigms to induce a comparable phenotype.

Potential of photon counting computed tomography derived spectral reconstructions to reduce beam-hardening artifacts in chest CT.

PURPOSE: Aim of the recent study is to point out a method to optimize quality of CT scans in oncological patients with port systems. This study investigates the potential of photon counting computed tomography (PCCT) for reduction of beam hardening artifacts caused by port-implants in chest imaging by means of spectral reconstructions. METHOD: In this retrospective single-center study, 8 ROIs for 19 spectral reconstructions (polyenergetic imaging, monoenergetic reconstructions from 40 to 190 keV as well as iodine maps and virtual non contrast (VNC)) of 49 patients with pectoral port systems undergoing PCCT of the chest for staging of oncologic disease were measured. Mean values and standard deviation (SD) Hounsfield unit measurements of port-chamber associated hypo- and hyperdense artifacts, bilateral muscles and vessels has been carried out. Also, a structured assessment of artifacts and imaging findings was performed by two radiologists. RESULTS: A significant association of keV with iodine contrast as well as artifact intensity was noted (all p < 0.001). In qualitative assessment, utilization of 120 keV monoenergetic reconstructions could reduce severe and pronounced artifacts completely, as compared to lower keV reconstructions (p < 0.001). Regarding imaging findings, no significant difference between monoenergetic reconstructions was noted (all p > 0.05). In cases with very high iodine concentrations in the subclavian vein, image distortions were noted at 40 keV images (p < 0.01). CONCLUSIONS: The present study demonstrates that PCCT derived spectral reconstructions can be used in oncological imaging of the thorax to reduce port-derived beam-hardening artefacts. When evaluating image data sets within a staging, it can be particularly helpful to consider the 120 keV VMIs, in which the artefacts are comparatively low.

Prognostic Value of Standard Heart Failure Medication in Patients with Cardiac Transthyretin Amyloidosis.

Introduction: Cardiac transthyretin amyloidosis (ATTR) is a progressive, fatal disease leading to heart failure due to accumulation of amyloid fibrils in the interstitial space and may occur as a hereditary (ATTRv) or wild-type (ATTRwt) form. Guidelines recommend the use of ACE inhibitors (ACEis) and beta-blockers (BBs) as heart failure therapy (HFT) in all patients with symptomatic heart failure and reduced ejection fraction, independent of the underlying etiology. However, the prognostic benefit of ACEis and BBs in ATTR has not been elucidated in detail yet. We thus sought to retrospectively investigate the outcome of patients with ATTRwt or ATTRv under HFT. Methods: Medical records of 403 patients with cardiac ATTR (ATTRwt: n = 268, ATTRv: n = 135) were screened for long-term medication as well as clinical, laboratory, electrocardiographic and echocardiographic data. Patients were assessed between 2005 and 2020 at the University Hospital Heidelberg. Kaplan-Meier analysis was used to analyze potential differences in survival among different subgroups. Results: The mean follow-up was 28 months. In total, 43 patients (32%) with ATTRv and 140 patients (52%) with ATTRwt received HFT. Survival was significantly shorter in patients receiving HFT in ATTRv (46 vs. 83 months, p = 0.0007) vs. non-HFT. A significantly better survival was observed in patients with comorbidities (coronary artery disease, arterial hypertension) and HFT among ATTRwt patients (p = 0.004). No significant differences in survival were observed in the other subgroups. Conclusions: Survival analysis revealed a potential benefit of HFT in patients with ATTRwt and cardiac comorbidities such as coronary artery disease and/or arterial hypertension. In contrast, HFT should be used with caution in patients with ATTRv.

bDMARD can prevent the progression of AA amyloidosis to end-stage renal disease.

INTRODUCTION: AA amyloidosis (AA) can be the consequence of any chronic inflammatory disease. AA is associated with chronic inflammatory diseases (cid+AA), autoinflammatory syndromes (auto+AA) or AA of unknown origin or idiopathic AA (idio+AA). The major organ manifestation is renal AA that can progress to end-stage renal disease (ESRD) and multiple organ failure. MATERIALS AND METHODS: This study is a monocentric retrospective analysis of the renal outcome and survival of patients with cid+AA (n=34), auto+AA (n=24) and idio+AA (n=25) who were treated with cytokine-inhibiting biological disease-modifying antirheumatic drugs (bDMARDs). RESULTS: 83 patients with renal AA were identified and followed for a mean observational period of 4.82 years. C reactive protein (CRP), serum amyloid alpha and proteinuria were significantly reduced with bDMARD therapy. Progression to ESRD was prevented in 60% (cid+AA), 88% (auto+AA) and 81% (idio+AA) of patients. Tocilizumab was given to 34 patients with cid+AA and idio+AA and was more effective in reducing CRP and progression to ESRD and death compared with other bDMARDs. CONCLUSIONS: bDMARDs reduce systemic inflammation in various diseases, leading to a reduction of proteinuria and prevention of ESRD. Importantly, tocilizumab was more effective than other bDMARDs in controlling systemic inflammation in patients with chronic inflammatory diseases and idiopathic AA, leading to better renal and overall survival.

Results of a phase I trial with Haploidentical mbIL-21 ex vivo expanded NK cells for patients with multiply relapsed and refractory AML.

Natural killer (NK)-cells have potent anti-tumor effects, yet it remains unclear if they are effective for patients with relapsed acute myeloid leukemia (AML). In a phase I clinical trial, we treated 12 patients (median age 60 years) with refractory AML (median 5 lines of prior therapy, median bone marrow blast count of 47%) with fludarabine/cytarabine followed by 6 infusions of NK-cells expanded from haploidentical donors using K562 feeder cells expressing membrane-bound IL21 and 4-1BBL. Patients received 106-107/kg/dose. No toxicity or graft-versus-host disease (GVHD) was observed and MTD was not reached. Seven patients (58.3%) responded and achieved a complete remission (CR) with/without count recovery. Median time to best response was 48 days. Five responding patients proceeded to a haploidentical transplant from the same donor. After a median follow-up of 52 months, 1-year overall survival (OS) for the entire group was 41.7%, better for patients who responded with CR/CRi (57.14%), and for patients who responded and underwent transplantation (60%). Persistence and expansion of donor-derived NK-cells were identified in patients' blood, and serum IFNγ levels rose concurrently with NK cell infusions. A higher count-functional inhibitory KIR was associated with higher likelihood of achieving CR/CRi. In conclusion, we observed a significant response to ex vivo expanded NK-cell administration in refractory AML patients without adverse effects.

Establishing an MSU service in a medium-sized German urban area-clinical and economic considerations.

Background and purpose: Mobile stroke units (MSU) have been demonstrated to improve prehospital stroke care in metropolitan and rural regions. Due to geographical, social and structural idiosyncrasies of the German city of Mannheim, concepts of established MSU services are not directly applicable to the Mannheim initiative. The aim of the present analysis was to identify major determinants that need to be considered when initially setting up a local MSU service. Methods: Local stroke statistics from 2015 to 2021 were analyzed and circadian distribution of strokes and local incidence rates were calculated. MSU patient numbers and total program costs were estimated for varying operating modes, daytime coverage models, staffing configurations which included several resource sharing models with the hospital. Additional case-number simulations for expanded catchment areas were performed. Results: Median time of symptom onset of ischemic stroke patients was 1:00 p.m. 54.3% of all stroke patients were admitted during a 10-h time window on weekdays. Assuming that MSU is able to reach 53% of stroke patients, the average expected number of ischemic stroke patients admitted to MSU would be 0.64 in a 10-h shift each day, which could potentially be increased by expanding the MSU catchment area. Total estimated MSU costs amounted to € 815,087 per annum. Teleneurological assessment reduced overall costs by 11.7%. Conclusion: This analysis provides a framework of determinants and considerations to be addressed during the design process of a novel MSU program in order to balance stroke care improvements with the sustainable use of scarce resources.

Post-COVID syndrome and work ability 9-12 months after a SARS-CoV-2 infection among over 9000 employees from the general population.

Objectives: Evidence on the work-related societal impact of long-term health-related consequences following SARS-CoV-2 is emerging. We characterize the modified work ability index (mWAI) of employees 6 to 12 months after an acute infection compared to pre-infection. Methods: Analyses were based on a population-based, multi-center cross-sectional study including employees aged 18-65 years with positive SARS-CoV-2 polymerase chain reaction (tested between October 2020-April 2021 in defined geographic regions in Germany). Prevalences and results of adjusted logistic regression analyses were given. Results: In 9752 employees (mean age 45.6 years, 58% females, response 24%), n = 1217 (13.1%) participants were regarded as having low mWAI compared to pre-infection. Outpatient medical treatment, inpatient treatment, and admission to intensive care during infection were associated with mWAI <15th percentile (P15, each odds ratio [OR] >3.0). Post-COVID symptom clusters most strongly linked to mWAI

Photon-Counting Detector CT Virtual Monoenergetic Images in Cervical Trauma Imaging-Optimization of Dental Metal Artifacts and Image Quality.

OBJECTIVES: The aim of this study was to analyze the extent of dental metal artifacts in virtual monoenergetic (VME) images, as they often compromise image quality by obscuring soft tissue affecting vascular attenuation reducing sensitivity in the detection of dissections. METHODS: Neck photon-counting CT datasets of 50 patients undergoing contrast-enhanced trauma CT were analyzed. Hyperattenuation and hypoattenuation artifacts, muscle with and without artifacts and vessels with and without artifacts were measured at energy levels from 40 keV to 190 keV. The corrected artifact burden, corrected image noise and artifact index were calculated. We also assessed subjective image quality on a Likert-scale. RESULTS: Our study showed a lower artifact burden and less noise in artifact-affected areas above the energy levels of 70 keV for hyperattenuation artifacts (conventional polychromatic CT images 1123 ± 625 HU vs. 70 keV VME 1089 ± 733 HU, p = 0.125) and above of 80 keV for hypoattenuation artifacts (conventional CT images -1166 ± 779 HU vs. 80 keV VME -1170 ± 851 HU, p = 0.927). Vascular structures were less hampered by metal artifacts than muscles (e.g., corrected artifact burden at 40 keV muscle 158 ± 125 HU vs. vessels -63 ± 158 HU p < 0.001), which was also reflected in the subjective image assessment, which showed better ratings at higher keV values and overall better ratings for vascular structures than for the overall artifact burden. CONCLUSIONS: Our research suggests 70 keV might be the best compromise for reducing metal artifacts affecting vascular structures and preventing vascular contrast if solely using VME reconstructions. VME imaging shows only significant effects on the general artifact burden. Vascular structures generally experience fewer metal artifacts than soft tissue due to their greater distance from the teeth, which are a common source of such artifacts.

Optimizing Arterial Vessel Contrast in Portal Venous Phase with Virtual Monoenergetic Images from Photon-Counting Detector CT Scans of the Abdomen-First Clinical Experiences.

BACKGROUND: Photon-counting detector (PCD) computed tomography (CT) allows for the reconstruction of virtual monoenergetic images (VMI) at different thresholds. OBJECTIVE: The aim of our study was to evaluate the optimal arterial contrast in portal venous (pv) scans regarding objective parameters and subjective image quality for different virtual keV levels. METHODS: We identified 40 patients that underwent a CT scan with an arterial and pv phase on a PCD-CT (NAEOTOM alpha, Siemens Healthineers, Forchheim, Germany). The attenuation of abdominal arteries on pv phases was measured for different virtual keV levels in a monoenergetic+ application profile and for polychromatic (pc) arterial images. Two independent readers assessed subjective image quality, including vascular contrast in pv scans at different energy levels. Additionally, signal- and contrast-to-noise ratios (SNR and CNR) were measured. RESULTS: Our results showed increasing arterial attenuation levels with decreasing energy levels in virtual monoenergetic imaging on pv scans with the highest attenuation at 40 keV, significantly higher than in the pc arterial phase (439 ± 97 HU vs. 360 ± 97, p < 0.001). Noise, SNR, and CNR were worse at this energy level (p < 0.001). Pv VMI showed less noise at energy levels above 70 keV (all p < 0.001). Subjective image quality was rated best at 70 keV, vascular contrast was best at 40 keV. CONCLUSIONS: Our research suggests that virtual monoenergetic images at 40 keV in Mono+ mode derived from a PCD-CT can be a feasible alternative to a true arterial phase for assessment of vessels with worse CNR and SNR.

Ultra-low-dose photon-counting CT of paranasal sinus: an in vivo comparison of radiation dose and image quality to cone-beam CT.

PURPOSE: This study investigated the differences in subjective and objective image parameters as well as dose exposure of photon-counting CT (PCCT) compared to cone-beam CT (CBCT) in paranasal sinus imaging for the assessment of rhinosinusitis and sinonasal anatomy. METHODS: This single-centre retrospective study included 100 patients, who underwent either clinically indicated PCCT or CBCT of the paranasal sinus. Two blinded experienced ENT radiologists graded image quality and delineation of specific anatomical structures on a 5-point Likert scale. In addition, contrast-to-noise ratio (CNR) and applied radiation doses were compared among both techniques. RESULTS: Image quality and delineation of bone structures in paranasal sinus PCCT was subjectively rated superior by both readers compared to CBCT (P < .001). CNR was significantly higher for photon-counting CT (P < .001). Mean effective dose for PCCT examinations was significantly lower than for CBCT (0.038 mSv ± 0.009 vs. 0.14 mSv ± 0.011; P < .001). CONCLUSION: In a performance comparison of PCCT and a modern CBCT scanner in paranasal sinus imaging, we demonstrated that first-use PCCT in clinical routine provides higher subjective image quality accompanied by higher CNR at close to a quarter of the dose exposure compared to CBCT.

Reticulated livedoid skin patterns after soft-tissue filler-related vascular adverse events.

BACKGROUND: For the treatment of vascular adverse events caused by filler injections, duplex ultrasound imaging may be used. The findings of duplex ultrasound examination and the clinical features of reticulated livedoid skin patterns were compared with the hemifaces anatomy. OBJECTIVE: The objective of this study was to link the reticulated livedoid skin patterns to the corresponding duplex ultrasound findings and the facial perforasomes. METHODS: Duplex ultrasound imaging was used for the diagnosis and treatment of vascular adverse events. The clinical features and duplex ultrasound findings of 125 patients were investigated. Six cadaver hemifaces were examined to compare the typical livedo skin patterns with the vasculature of the face. RESULTS: Clinically, the affected skin showed a similar reticulated pattern in each facial area corresponding with arterial anatomy and their perforators in the cadaver hemifaces. With duplex ultrasound, a disturbed microvascularization in the superficial fatty layer was visualized. After hyaluronidase injection, clinical improvement of the skin pattern was seen. Normalization of blood flow was noted accompanied by restoration of flow in the corresponding perforator artery. The skin patterns could be linked to the perforators of the superficial fat compartments. CONCLUSION: The livedo skin patterns seen in vascular adverse events may reflect the involvement of the perforators.