Series Of Images Research Articles

Combined PVI and LAAC is feasible using RFA or PFA in a canine model despite acute tissue edema in PFA versus RFA

Abstract Background Combined procedure with pulmonary vein isolation (PVI) using thermal energy followed by left atrial appendage closure (LAAC) has been used in select patient populations with positive results. Pulsed field ablation (PFA) is a novel non-thermal ablation modality that ablates cardiac tissue by irreversible electroporation. The effect of PFA on cardiac tissue and its interaction with a LAAC device in a single procedure has not been studied. Purpose To evaluate using transesophageal echo (TEE) imaging the acute tissue response following ablation by PFA compared to radiofrequency ablation (RFA) and its interaction with the WATCHMAN FLX Pro LAAC device when used in a combined procedure in a healthy canine model. Methods Nine mongrel canines underwent PVI using either circumferential PFA (FARAPULSE) energy application (n=6) or RFA energy (n=3). TEE imaging was obtained at the time of the procedure before and immediately after ablation energy application. The general appearance and echogenicity of the left lateral ridge was assessed and the os of the left atrial appendage (LAA) was measured in the four standard TEE views (0, 45, 90, and 135 degrees). Decisions about device sizing were made accordingly. PVI was evaluated by entry and exit block in all veins except the right inferior pulmonary vein (RIPV), which was not ablated. Following ablation, the LAAC device was implanted using TEE and fluoroscopic guidance in all animals and the percentage of compression measured. PASS criteria were assessed before the release of each device. All animals received dual antiplatelet therapy post implant. Results PVI was confirmed in all animals (except RIPV which was not targeted for ablation) using PFA and RFA. LAA dimensions (at device landing site) did not change substantially after RF ablation. With PFA, there was evidence of more diffuse edema and decrease in LAA diameter (Table). The LAAC device was implanted successfully after meeting PASS criteria in all animals within 30 minutes post ablation. The device size was decreased following PFA in two (2/6) animals, whereas there was no deviation from baseline measurements in device size for any of the RFA animals. Average LAAC device compression was higher for PFA versus RFA animals (Table). TEE post implant confirmed absence of any peri-device leaks in all animals. Conclusion Concomitant PVI using PFA (FARAPULSE) and LAAC (WATCHMAN FLX Pro) is feasible with 100% success and no residual acute peri-device leak. In the canine model, PFA is associated with more diffuse edema compared to RFA, which might affect device sizing. Long term consequences of this acute edema need to be evaluated in serial imaging and future larger clinical trials.Table

Sex differences in clinical characteristics, phenotypes, management, and long-term outcomes of myocardial injury: an international cohort study

Abstract Background Several studies have demonstrated sex differences in patients presenting to the emergency department (ED) with myocardial infarction, heart failure or syncope. Whether sex-specific differences in chest pain patients with myocardial injury exist is unknown. Purpose To determine whether sex-specific differences in the clinical characteristics, phenotypes, management, and long-term outcomes of patients with myocardial injury exist. Methods Patients presenting to the ED with chest pain suggestive of MI were consecutively enrolled into a prospective multicenter international diagnostic study. Final diagnoses were centrally adjudicated by two independent cardiologists, applying the fourth universal definition of myocardial infarction, using all available medical records, including serial hs-cTn and cardiac imaging. Follow-ups were performed at 3 months, 1-, 2- and 5-years. The primary outcome was 5-year all-cause mortality. Secondary outcomes included 5-year cardiovascular mortality and non-cardiovascular mortality. Multivariable flexible parametric (Royston-Parmar) models assuming proportional hazards were fitted. Models were adjusted for age, history of coronary artery disease, history of malignancy, diabetes, hypertension, smoking status, history of liver disease, and renal function. Results Among 8046 chest pain patients presenting to the ED, 1158 (14.4%) had myocardial injury, of which 358 (31%) were females and 800 (69%) males. Women were older (79 years, vs. 73 years), had fewer cardiovascular risk factors and comparable non-cardiovascular comorbidities except for lung disease which was more commonly found in men. Myocardial injury phenotypes varied between sexes (Figure). The most common phenotype in both sexes was heart failure, yet it was more common in men (37.2%) than in women (22.3%). The second most common phenotype in women was hypertension (15.4%) and arrhythmia (15.4 %), while in men was myocarditis (17.8 %), followed by arrhythmia (15.8%). Women underwent less invasive coronary angiography (19.8% vs 26.9%) or stress testing (12% vs 21.5%). In the angiographic findings, women presented more often with normal findings (30.4% vs. 19.6%) or mild CAD (20.3% vs. 11.2%) whereas men displayed more frequently 3-vessel disease (14.5% vs. 36.4%), Table. After adjusting for known confounders, women were associated with a lower 5-years risk for all-cause mortality (HR 0.69; 95%CI: 0.56–0.83) and cardiovascular mortality (HR 0.61; 95%CI: 0.46–0.79). No statistically significant difference in non-cardiovascular mortality risk was found (HR 0.79; 95%CI: 0.59-1.04). Conclusions Women presenting with chest pain to the ED and having myocardial injury were less likely than men to undergo coronary angiography or non-invasive cardiac imaging. Long-term risk for all-cause or cardiovascular mortality was lower for women compared to men.Myocardial Injury phenotypesPatient management

Angioprotein-like 3 and atheroma progression in statin-treated type 2 diabetic patients with coronary artery disease: the pre-specified analysis from the OPTIMAL randomized controlled trial

Abstract Introduction Despite guideline-recommended control of LDL-C with a statin, type 2 diabetic patients more likely cause cardiovascular events. This indicates the need to identify additional therapeutic targets in those patients. Angioprotein-like 3 (ANGPTL3) is an inhibitor of lipoprotein and endothelial lipase, which increases the levels of LDL-C and other atherogenic lipoproteins. These properties suggest ANGPTL3 as a potential driver associated with diabetic atherosclerosis. The OPTIMAL randomized controlled trial (jRCT1052180152) compared the efficacy of continuous glucose monitoring-guided versus HbA1c-guided glycemic control on coronary atherosclerosis in statin-treated type 2 diabetic patients by using serial intravascular ultrasound (IVUS) imaging. This pre-specified analysis of the OPTIMAL study was designed to evaluate whether ANGPTL3 affects progression of coronary atheroma in statin-treated type 2 diabetic patients. Purpose To elucidate the association of serial change in ANGPTL3 with the degree of atheroma progression in statin-treated type 2 diabetic patients. Methods 59 patients (59 lesions) with serial ANGPTL3 levels at baseline and week 48 were included into the current analysis. Clinical demographics and IVUS-derived measure were compared in patients with and without any increase in ANGPTL3. Results All of study subjects received a statin, and over 60% of them were treated with high-intensity statin. Under these lipid-lowering therapies, any increase in ANGPTL3 levels at week 48 was observed in 52.5% of study participants. Patients with any increase in ANGPTL3 were more likely to have a history of hypertension (90.0% vs. 64.3%, p=0.02), whereas there was no significant difference in on-treatment LDL-C levels between the two groups (1.8 ± 0.4 vs. 1.6 ± 0.6 mmol/L, p=0.25) (Table). On IVUS imaging analysis, baseline percent atheroma volume (PAV) did not differ in those with and without any increase in ANGPTL3. However, patients with any increase in ANGPTL3 presented a greater progression of PAV (0.08 ± 0.28 vs. -0.74 ± 0.29, p=0.04). There was a trend toward a lower frequency of PAV regression in those exhibiting any increase in ANGPTL3 (48.4% vs. 57.1%), but this comparison did not meet statistical significance (p=0.50) (Figure). Multivariate analysis adjusting clinical characteristics demonstrated that any increase in ANGPTL3 level was not independently associated with PAV progression (β=0.16, 95%CI=-0.01 – 0.18, p=0.27). Conclusion Over 50% of statin-treated type 2 diabetic patients with coronary atherosclerosis showed any increase in ANGPTL3 levels at week 48. Serial IVUS imaging revealed that patients with any increase in ANGPTL3 more likely presented a greater atheroma progression. However, this relationship did not exist after adjusting clinical characteristics. Our findings suggest that ANGPTL3 may not be a pivotal driver associated with atheroma progression in statin-treated type 2 diabetic patients.

The safety of standardized management of suspected cardiovascular immune-related events in patients treated by immunecheckpoints inhibitors

Abstract Background Immune checkpoint inhibitors (ICIs) treatment carries a risk of immune-related adverse events (irAEs), including cardiovascular (CV) events. Current guidelines recommend troponin testing to detect early CV irAEs, especially myocarditis, prompting hospital admission. However, high volumes might hinder hospital admission for all suspected CV irAEs patients. Purpose To assess the safety of standardized management in outpatients with suspected irAEs. Methods A prospective single-center cohort study was conducted, including all adults referred to our unit for suspected CV irAEs. Patients exhibiting CV symptoms, receiving double ICIs, or showing ECG changes were referred to cardiology or intensive care based on severity. Patients with no CV symptoms or ECG changes, on single ICI therapy, and no other immune disorder were assessed in a day stay within 8 working days. Patients underwent serial serum testing, ECG, transthoracic echocardiogram, and cardiac magnetic resonance imaging (cMRI) and were assessed by a multidisciplinary team (MDT) including cardiology and internal medicine specialists. Coronary artery imaging and endomyocardial biopsy were performed when deemed necessary (Figure 1). The primary endpoint was CV mortality at 30 days after referral. Secondary endpoints included identifying factors associated with the diagnosis of CV irAEs at referral. Events were adjudicated by a panel of experts (FC, MM, SH) who reviewed the MDT's weekly meeting conclusions. Results 175 patients were enrolled from March 2022 to October 2023; 40 (22.89%) were male, median age 61 (IQR 48.0-72.0) years. 146 (83.4%) were seen in the outpatient clinic. No CV deaths occurred within the initial 30 days. 95 patients (54.1%) had CV irAEs at referral, including 72 (41.1%) with myocarditis; 10 (5.7%) with acute coronary syndromes; 9 (5.1%) with pericarditis; 7 (4.0%) with heart failure; 4 (2.3%) with high-degree conduction or ventricular arrhythmias; and 1 (0.6%) with Tako-Tsubo. 8 (4.6%) had a combination of CV irAEs. The majority of patients admitted to the hospital had CV irAEs (24, 82.7%). On multivariable regression analysis(Figure 2), CV or muscle symptoms(OR 2.677 [CI 1.207-5.937], p=0.015), prior CV disease history(OR 3.668 [CI 1.486-9.057], p=0.0048), and abnormal ECG (OR 2.855 [CI 1.074-7.589], p=0.035) remained associated with CV irAEs at referral. Including global longitudinal strain (GLS) in the model, we identified prior CV disease history. (OR 7.011 [CI 2.217-22.167], p=0.0009) and GLS <16% (OR 2.774 [CI 1.07-7.17], p=0.035) as significant. Conclusions We demonstrate the safety of a standardized outpatient management approach for most patients referred for suspected CV irAEs, mainly triggered by asymptomatic elevation of troponin. No patient experienced CV death at 30 days. When suspecting a CV irAEs, CV or muscle symptoms, previous history of CV disease, and abnormal ECG should prompt speedy assessment given the higher likelihood of CV irAEsFigure 1

Long-term safety and efficacy of antibody ALXN2220 for depletion of cardiac amyloid transthyretin: results of treatment beyond 12 months in the open-label extension of study NI006-101

Abstract Introduction ALXN2220 (formerly NI006) is an investigational human monoclonal antibody in development for the treatment of transthyretin-mediated amyloid cardiomyopathy (ATTR-CM). ALXN2220 is designed to deplete cardiac amyloid transthyretin (ATTR) deposits in patients with ATTR-CM on top of standard of care. Data from the first-in-human, ascending dose study NI006-101 show that ALXN2220 is safe and well tolerated. A reduction of surrogate markers of cardiac amyloid load and cardiac biomarkers was observed in participants receiving doses of ≥ 10mg/kg of ALXN2220 over a period of 12 months of treatment. Purpose Long-term safety, tolerability and efficacy of ALXN2220 treatment beyond 12 months was studied in a prolonged Open-Label Extension (OLE) of the NI006-101 study. Methods Participants completing 12 months in dose cohorts ≤ 30 mg/kg were allowed to receive additional 6 to 12 monthly open-label ALXN2220 infusions with up-titration of all participants to 30 mg/kg. Cardiac biomarkers were measured centrally, and serial cardiac imaging was performed with echocardiography and cardiac MRI or scintigraphy. Results Out of 27 participants completing 12 months, 23 (18 ATTRwt, all male, median age 70 years at screening (range 28-83)) continued treatment in the prolonged OLE. Median number of infusions of ALXN2220 received and median time followed across the full study were 20 infusions (range 11-24) and 125 weeks (range 83-153). Overall adherence to treatment was high in the prolonged OLE, 97% of planned infusions administered, 87% of participants received all planned doses. No severe or serious adverse events were considered related to ALXN2220 or resulted in the discontinuation during OLE, and no events of cytokine release syndrome or thrombocytopenia were observed. None of the participants had anti-drug antibodies throughout the trial. Cardiac biomarkers (NT-proBNP, troponin) and cardiac imaging indicated continued treatment effects beyond 12 months and supported the up-titration of participants who previously received lower doses of ALXN2220. Conclusions Up-titration and long-term treatment at a dose level of 30 mg/kg in the OLE was safe and well tolerated, with overall good adherence to treatment. Cardiac imaging and cardiac biomarker data indicated continued treatment effects beyond 12 months and supported the up-titration of patients to 30 mg/kg.

Body mass index as a contributor to the accumulation of lipidic plaque materials in statin-treated type 2 diabetic patients with coronary artery disease: sub-analysis from the OPTIMAL randomized study

Abstract Background Patients with type 2 diabetes mellitus more likely exhibit obesity. Pathophysiologically, obesity promotes a range of metabolic disturbances including insulin resistance, dyslipidemia and hypertension, in addition to the secretion of adipokines and pro-inflammatory cytokines from excessive fat accumulation. These atherogenic features may promote instability of atherosclerotic plaques, which ultimately result in elevating a risk of atherosclerotic cardiovascular disease. However, it remains to be fully elucidated how obesity affects atherosclerotic plaque features in type 2 diabetic patients with coronary artery disease (CAD). Near-infrared spectroscopy (NIRS) imaging enables to quantitatively visualize lipidic plaque materials in vivo. This imaging modality provides insights into lipidic plaque features in obese patients with type 2 diabetes mellitus. Purpose To elucidate the association of body mass index (BMI, kg/m2) with lipidic plaque materials in type 2 diabetic patients. Methods The OPTIMAL study was a prospective randomized controlled trial to evaluate the efficacy of continuous glucose monitoring (CGM) guided glycemic control on coronary atherosclerosis in statin-treated type 2 diabetic participants with CAD requiring PCI. 94 patients were randomized into CGM-guided or HbA1c-guided glycemic control. Serial NIRS imaging was conducted to monitor non-culprit lesions at baseline and week 48. The current sub-analysis included 78 patients with both baseline BMI data and evaluable baseline NIRS/IVUS images. Results All of study subjects received a statin (high-intensity statin use=36%), and the averaged LDL-C level was 86.7±26.3 mg/dL. The average BMI and HbA1c level were 24.7±3.1 kg/m2 and 7.5±0.9%, respectively (Table 1). On NIRS imaging analysis, maxLCBI4mm at non-culprit lesions was 286.2±167.0, and 21.8% of study subjects exhibited maxLCBI4mm >400 (Table 2). BMI was associated with maxLCBI4mm (p<0.001). Multivariate analysis adjusting clinical characteristics and LDL-C demonstrated that BMI was an independent contributor to maxLCBI4mm [estimate=17.15 (12.88-21.42), p<0.001] (Table 2). Even in patients receiving high-intensity statin, BMI was still associated with maxLCBI4mm (p<0.001). Conclusions A greater accumulation of lipidic plaque materials was observed in association with BMI in statin-treated type 2 diabetic patients with CAD. This presence of enhanced plaque vulnerability at non-culprit lesions, in the setting of obesity, may contribute to an increased risk of cardiovascular events in type 2 diabetic patients with CAD. The current finding suggests the need to adopt further therapeutic approaches to favourably modify plaque vulnerability in type 2 diabetic patients exhibiting obesity.Table 1:Clinical DemographicsTable 2:Factors Associated with maxLCBI

Predictors of LV reverse remodeling after SAVR: insights from a prospective TTE and CMR study in patients with severe aortic stenosis

Abstract Background Left ventricular (LV) remodeling in patients with severe aortic stenosis (AS) is believed to be reversible after pressure overload relieve, as provided by both surgical (SAVR) or transcatheter aortic valve replacement. However, LV reverse remodeling (RR) is far from uniform in patients with AS and the same clinical indication for treatment. Aim To determine the prevalence and imaging predictors of LV RR after SAVR in patients with severe symptomatic AS. Methods single-center, prospective cohort study enrolling 119 patients with severe symptomatic AS (age 71±8y, 49% male; mean transaortic gradient 62±18mmHg, mean indexed aortic valve area (AVAi) 0.40±0.10 cm2/m2, mean LV ejection fraction by TTE 58±9%), with no previous history of ischemic cardiomyopathy, undergoing SAVR between 2019 and 2022. All patients underwent serial imaging assessment beyond clinical characterization (transthoracic echocardiogram – TTE, and 1.5T cardiac magnetic resonance - CMR) prior to surgery and at the 3rd to 6th month post-SAVR. Endomyocardial biopsy (EMB) for myocardial fibrosis quantification (Masson ́s Trichrome histochemistry) was performed during SAVR. LV RR was defined when in presence of at least one of the imaging criteria: > 15% reduction in LV end-diastolic indexed volume (LVEDV) by CMR; > 15% reduction in LV indexed mass (LVM) by CMR; > 15% reduction in LV geometric remodeling by CMR; >10% increase in LV ejection fraction (LVEF) either from TTE or CMR; > 50% increase in global longitudinal strain (GLS) at TTE. Clinical, imaging and histology derived data were compared in patients with post-SAVR LV RR and for each of the defined criteria. Results 107 patients (90%) met at least one criteria of LV RR. Morphological criteria were more prevalent than LV functional improvement after SAVR (Figure 1). In patients who met at least one criteria of LV RR, no differences were found between NT- proBNP, LV tissue characterization (by CMR) or myocardial fibrosis at EMB. Yet, those with LV RR had significantly smaller preoperative AVAi (0.4±0.9 vs 0.5±0.9 cm2/m2, p=0.007) and higher mean valvular gradients (62±18 vs 49±12 mmHg, p=0.017). Considering individual LV RR criteria, patients with higher NT-proBNP levels met LVEF and morphological (LVEDV and LVM) LV RR criteria (p=0.027, p=0.016 and p= 0.003, respectively). Patients with higher % of late gadolinium enhancement on pre-operative CMR [7.8 (IQR 2.5-11.3) vs. 1.6 (IQR 0-5.2)%, p=0.017] had significant GLS improvement after SAVR. Conclusion In a cohort of patients with classical severe, symptomatic AS, LV RR is common after SAVR, occurring in almost 9 out of every 10 patients. Both indexes of worse valve narrowing and pre-operative LV adaptation are associated with favorable RR after surgery. This underlines the benefits of a timely intervention even in patients with more advanced disease.

Segmentation and Metallographic Evaluation of Aluminium Slurry Coatings Using Machine Learning Techniques

AbstractAnalysis of scanning electron microscope (SEM) images is crucial for characterising aluminide diffusion coatings deposited via the slurry route on steels, yet challenging due to various factors like imaging artefacts, noise, and overlapping features such as resin, precipitates, cracks, and pores. This study focuses on determining the thicknesses of the coating layers Fe2Al5 and, if present, FeAl, pore characteristics, and chromium precipitate fractions after the heat treatment that forms the diffusion coating. A deep learning SEM image segmentation model utilising U-Net architecture is proposed. Ground truth data were generated using the trainable Weka segmentation plugin in ImageJ, manually refined for accuracy, and supplemented with synthetic data from Blender 3D software for data augmentation of a limited number of SEM label images. The deep learning model trained on a combination of synthetic and real SEM data achieved mean dice scores of 98.7% ± 0.2 for the Fe2Al5 layer, 82.6% ± 8.1 for pores, and 81.48% ± 3.6 for precipitates when evaluated on manually labelled SEM data. The deep learning procedure was applied to evaluate a series of SEM images of diffusion coatings obtained with three different slurry compositions. The evaluation revealed that using a slurry without a rheology modifier may lead to a thicker partial Fe2Al5 layer that is formed by inward diffusion. The relation between the outward and inward diffusion Fe2Al5 layers was not affected by the coating thickness. The thinner diffusion coating presents lower pores and chromium precipitate fractions independently of the slurry selected.

Ultra-High-Resolution Photon-Counting Detector CT Benefits Visualization of Abdominal Arteries: A Comparison to Standard-Reconstruction.

This study aimedto investigate the potential benefit of ultra-high-resolution (UHR) photon-counting detector CT (PCD-CT) angiography in visualization of abdominal arteries in comparison to standard-reconstruction (SR) images of virtual monoenergetic images (VMI) at low kiloelectron volt (keV).We prospectively included 47 and 47 participants to undergo contrast-enhanced abdominal CT scans within UHR mode on a PCD-CT systemusing full-dose (FD) and low-dose (LD) protocols, respectively. The data were reconstructed into six series of images: FD_UHR_Br48, FD_UHR_Bv56, FD_UHR_Bv60, FD_SR_Bv40, LD_UHR_Bv48, and LD_SR_Bv40. The UHR reconstructions were performed with three kernels (Bv48, Bv56, and Bv60) within 0.2mm. The SR were virtual monoenergetic imaging reconstruction with Bv40 kernel at 40-keV within 1mm. Each series of axial images were reconstructed into coronal and volume-rendered images. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of seven arteries were measured. Three radiologists assessed the image quality, and visibility of nine arteries on all the images.SNR and CNR values of SR images were significantly higher than those of UHR images (P < 0.001). The SR images have higher ratings in image noise (P < 0.001), but the FD_UHR_Bv56 and FD_UHR_Bv60 images has higher rating in vessel sharpness (P < 0.001). The overall quality was not significantly different among FD_VMI_40keV, LD_VMI_40keV, FD_UHR_Bv48, and LD_UHR_Bv48 images (P > 0.05) but higher than those of FD_UHR_Bv56 and FD_UHR_Bv60 images (P < 0.001). There is no significant difference of nine abdominal arteries among six series of images of axial, coronal and volume-rendered images (P > 0.05).To conclude, 1-mm SR image of VMI at 40-keV is superior to 0.2-mm UHR regardless of which kernel is used to visualize abdominal arteries, while 0.2-mm UHR image using a relatively smooth kernel may allow similar image quality and artery visibility when thinner slice image is warranted.

Evolution of Left Ventricular Thrombus on Serial Cardiovascular Magnetic Resonance Imaging.

Current management of left ventricular (LV) thrombus relies on limited, non-contemporary, echocardiography-based studies. Data on LV thrombus evolution and the associated embolic risk are scarce. We aimed to describe the evolution of LV thrombus on serial cardiovascular magnetic resonance imaging (CMR) - the current reference standard for the detection of LV thrombus, and identify correlates of no resolution and the embolic risk associated with resolution status. We conducted a retrospective cohort study of 107 consecutive patients with LV thrombus who had 213 serial CMRs at a median of 255 days after the index CMR. Of these, 97.2% were anticoagulated. At 3 months after detection by CMR, 75% (47/63) had no resolution of LV thrombus; at 6 months, 53% (35/66) had no resolution; and at 12 months, 37% (23/63) had no resolution. Correlates of no resolution at 6 months included a history of myocardial infarction, LV aneurysm, ischemic etiology of cardiomyopathy, and larger thrombus volume. Recurrence of LV thrombus was rare at 5.3%. On survival analysis using the landmark analysis method, embolic events often occurred beyond 6 months, more frequently in patients with unresolved LV thrombus. Our findings challenge previous literature by demonstrating a lower rate of resolution of LV thrombus and substantial embolic risk beyond 6 months associated with unresolved LV thrombus on serial CMR. Our findings advocate for extended anticoagulation, particularly in patients with markers associated with no resolution. These findings have important implications for clinical practice and research into managing patients with LV thrombus.

Gender and Ethnicity Bias of Text-to-Image Generative Artificial Intelligence in Medical Imaging, Part 2: Analysis of DALL-E 3.

Disparity among gender and ethnicity remains an issue across medicine and health science. Only 26%-35% of trainee radiologists are female, despite more than 50% of medical students' being female. Similar gender disparities are evident across the medical imaging professions. Generative artificial intelligence text-to-image production could reinforce or amplify gender biases. Methods: In March 2024, DALL-E 3 was utilized via GPT-4 to generate a series of individual and group images of medical imaging professionals: radiologist, nuclear medicine physician, radiographer, nuclear medicine technologist, medical physicist, radiopharmacist, and medical imaging nurse. Multiple iterations of images were generated using a variety of prompts. Collectively, 120 images were produced for evaluation of 524 characters. All images were independently analyzed by 3 expert reviewers from medical imaging professions for apparent gender and skin tone. Results: Collectively (individual and group images), 57.4% (n = 301) of medical imaging professionals were depicted as male, 42.4% (n = 222) as female, and 91.2% (n = 478) as having a light skin tone. The male gender representation was 65% for radiologists, 62% for nuclear medicine physicians, 52% for radiographers, 56% for nuclear medicine technologists, 62% for medical physicists, 53% for radiopharmacists, and 26% for medical imaging nurses. For all professions, this overrepresents men compared with women. There was no representation of persons with a disability. Conclusion: This evaluation reveals a significant overrepresentation of the male gender associated with generative artificial intelligence text-to-image production using DALL-E 3 across the medical imaging professions. Generated images have a disproportionately high representation of white men, which is not representative of the diversity of the medical imaging professions.

Gender and Ethnicity Bias of Text-to-Image Generative Artificial Intelligence in Medical Imaging, Part 1: Preliminary Evaluation.

Generative artificial intelligence (AI) text-to-image production could reinforce or amplify gender and ethnicity biases. Several text-to-image generative AI tools are used for producing images that represent the medical imaging professions. White male stereotyping and masculine cultures can dissuade women and ethnically divergent people from being drawn into a profession. Methods: In March 2024, DALL-E 3, Firefly 2, Stable Diffusion 2.1, and Midjourney 5.2 were utilized to generate a series of individual and group images of medical imaging professionals: radiologist, nuclear medicine physician, radiographer, and nuclear medicine technologist. Multiple iterations of images were generated using a variety of prompts. Collectively, 184 images were produced for evaluation of 391 characters. All images were independently analyzed by 3 reviewers for apparent gender and skin tone. Results: Collectively (individual and group characters) (n = 391), 60.6% were male and 87.7% were of a light skin tone. DALL-E 3 (65.6%), Midjourney 5.2 (76.7%), and Stable Diffusion 2.1 (56.2%) had a statistically higher representation of men than Firefly 2 (42.9%) (P < 0.0001). With Firefly 2, 70.3% of characters had light skin tones, which was statistically lower (P < 0.0001) than for Stable Diffusion 2.1 (84.8%), Midjourney 5.2 (100%), and DALL-E 3 (94.8%). Overall, image quality metrics were average or better in 87.2% for DALL-E 3 and 86.2% for Midjourney 5.2, whereas 50.9% were inadequate or poor for Firefly 2 and 86.0% for Stable Diffusion 2.1. Conclusion: Generative AI text-to-image generation using DALL-E 3 via GPT-4 has the best overall quality compared with Firefly 2, Midjourney 5.2, and Stable Diffusion 2.1. Nonetheless, DALL-E 3 includes inherent biases associated with gender and ethnicity that demand more critical evaluation.

Blind Recognition of Frame Synchronization Based on Deep Learning.

In this paper, a deep-learning-based frame synchronization blind recognition algorithm is proposed to improve the detection performance in non-cooperative communication systems. Current methods face challenges in accurately detecting frames under high bit error rates (BER). Our approach begins with flat-top interpolation of binary data and converting it into a series of grayscale images, enabling the application of image processing techniques. By incorporating a scaling factor, we generate RGB images. Based on the matching radius, frame length, and frame synchronization code, RGB images with distinct stripe features are classified as positive samples for each category, while the remaining images are classified as negative samples. Finally, the neural network is trained on these sets to classify test data effectively. Simulation results demonstrate that the proposed algorithm achieves a 100% probability in frame recognition when BER is below 0.2. Even with a BER of 0.25, the recognition probability remains above 90%, which exhibits a performance improvement of over 60% compared with traditional algorithms. This work addresses the shortcomings of existing methods under high error conditions, and the idea of converting sequences into RGB images also provides a reliable solution for frame synchronization in challenging communication environments.

3D micromorphological reconstruction and roughness characterization of wood surface based on sequence images

A novel non-contact optical inspection technique is proposed to precisely reconstruct the three-dimensional surface structure of wood and evaluate its roughness. The feasibility of using image fusion techniques to characterize the 3D roughness of wood surfaces is explored by combining high-resolution serial image acquisition techniques with advanced data processing methods. The work focuses on examining various cut surfaces of three distinct wood species: Larch, Catalpa, and Toona sinensis. The proposed 3D roughness parameters are verified using 3D reconstruction and precise measurements. The experimental results demonstrate that the proposed method exhibits strong adaptability in measuring wood surface roughness and achieves a high degree of consistency with the results obtained from traditional digital microscope systems. This study not only validates the possible use of multilayer sequence image fusion technology in measuring wood roughness, but also establishes a solid basis for the creation of 3D assessment criteria for wood surface roughness and associated inspection systems.

Feasibility of thin-slice, low noise images created using multi-kernel synthesis to replace multiple image series in head CT.

SynthesiZed Improved Resolution and Concurrent nOise reductioN (ZIRCON) is a multi-kernel synthesis method that creates a single series of thin-slice computed tomography (CT) images displaying low noise and high spatial resolution, increasing reader efficiency and minimizing partial volume averaging. To compare the diagnostic performance of a single set of ZIRCON images to two routine clinical image series using conventional CT head and bone reconstruction kernels for diagnosing intracranial findings and fractures in patients with trauma or suspected acute neurologic deficit. In total, 50 patients underwent clinically indicated head CT in the ER (15 normal, 35 abnormal cases). A non-reader neuroradiologist established the reference standard. Three neuroradiologists reviewed two routine clinical series (head and bone kernels) and a single ZIRCON series, detecting intracranial findings or fractures and rating confidence (0-100). Sensitivity, specificity, and jackknife free-response receiver operating characteristic (JAFROC) figure of merit (FOM) were compared (limit of non-inferiority: -0.10). ZIRCON and conventional images demonstrated comparable performance for fractures (sensitivity: 51.5% vs. 54.5%; specificity: 40.2% vs. 34.2%) and intracranial findings (sensitivity: 88.2% vs. 91.4%; specificity: 77.2% vs. 73.7%).The estimated difference of JAFROC FOM demonstrated ZIRCON non-inferiority for acute pathologies overall (0.003 [95% CI=-0.051-0.057]) and fractures (0.048 [95% CI=-0.050-0.145]) but not for intracranial findings alone (-0.024 [95% CI=-0.100-0.052]). Thin-slice, low noise, and high spatial resolution images can be created to display intracranial findings and fractures replacing multiple images series in head CT with similar performance. Future studies in more patients and further algorithmic development are warranted.

Diffuse meningeal melanocytosis – a silent culprit

Abstract Introduction/Objective Diffuse meningeal melanocytosis is a rare melanocytic proliferation that poses significant risk of severe hydrocephalus and mortality among children and young adults. Although the clonal melanocytes do not typically exhibit malignant morphological features, their capability for extensive invasion and malignant-like behavior necessitates tissue biopsy alongside immunohistochemical and molecular testing for definitive diagnosis. Methods/Case Report A 17-year-old male presented with progressive headaches, photophobia, and nausea, initially attributed to migraines. Neuro-opthalmological assessment revealed papilledema, leading to a diagnosis of idiopathic intracranial hypertension. Serial imaging showed fluctuating leptomeningeal enhancement and moderate communicating hydrocephalus without parenchymal lesions. Therapeutic lumbar punctures provided modest symptom improvement; increased opening pressure was observed. Evaluation of seven CSF specimens showed low glucose levels, increased cellularity consisting of bland appearing epithelioid cells of unknown etiology, and increased lymphocytes. Infectious causes were excluded. Due to the indeterminate CSF findings, discussion between the cytopathologist and neuro-opthamologist was crucial to facilitate tissue biopsy to exclude a neoplastic process. Subsequent shunt placement and cerebral cortex biopsy revealed neoplastic cells with sheet-like architecture coating the dura without overt brain invasion. The tumor cells had eosinophilic cytoplasm without pigment and enlarged nuclei with irregular contours, vesicular chromatin, and prominent nucleoli. No high-grade features were seen. Immunohistochemical stains were positive for MART1, HMB45, and PRAME, consistent with a melanocytic lesion. FISH melanoma panel was negative. The final diagnosis was diffuse meningeal melanocytic neoplasm, most consistent with meningeal melanocytosis. The patient received chemotherapy with improved symptoms and stable disease. Results (if a Case Study enter NA) NA Conclusion Diffuse meningeal melanocytosis is a challenging cytologic diagnosis as melanocytes can morphologically mimic lymphocytes and monocytes, and the low cellularity of CSF specimens often results in insufficient cell blocks for ancillary tests. The direct communication of the pathologist with the clinical team to correlate pathology, radiology, and clinical symptoms was essential to ensure the proper management of this patient.

B-FLOWS: Biofouling Focused Learning and Observation for Wide-Area Surveillance in Tidal Stream Turbines

Biofouling, the accumulation of marine organisms on submerged surfaces, presents significant operational challenges across various marine industries. Traditional detection methods are labor intensive and costly, necessitating the development of automated systems for efficient monitoring. The study presented in this paper focuses on detecting biofouling on tidal stream turbine blades using camera-based monitoring. The process begins with dividing the video into a series of images, which are then annotated to identify and select the bounding boxes containing objects to be detected. These annotated images are used to train YOLO version 8 to detect biofouled and clean blades in the images. The proposed approach is evaluated using metrics that demonstrate the superiority of this YOLO version compared to previous ones. To address the issue of misdetection, a data augmentation approach is proposed and tested across different YOLO versions, showing its effectiveness in improving detection quality and robustness.

6714 Bone And Radiologic Findings In Congenital Generalized Lipodystrophy: A Systematic Review

Abstract Disclosure: R.M. Tuska: None. M. Brush: None. A.A. Livinski: None. R.J. Brown: None. Congenital Generalized Lipodystrophy (CGL) is characterized by a near-total loss of subcutaneous adipose tissue, leading to severe metabolic and systemic comorbidities. CGL is most commonly caused by mutations in AGPAT2 (CGL1) and BSCL2 (CGL2) genes. Skeletal abnormalities such as diffuse sclerosis, lytic bone lesions, and high bone mineral density (BMD) have been recognized in many patients with CGL, but the radiologic and clinical features of these bone phenotypes remain ill-defined. The aim of this systematic review was to evaluate the bone manifestations and radiologic findings associated with CGL1 and CGL2. We searched 6 databases: CINAHL Plus, Embase, Global Index Medicus (WHO), PubMed, Scopus, and Web of Science: Core. We screened articles utilizing a dual reviewer process in Covidence. Included publications reported primary bone and radiologic findings in patients with CGL1 or CGL2. Exclusions comprised publications without full text, duplicate publications, those lacking bone measures, and review articles. Two reviewers extracted data using RedCap and assessed risk of bias. 270 records were screened and 37 records reporting 179 cases of CGL were included for data extraction. Among the 79 patients assessed for bone cysts, 49 (62%) exhibited lytic appearing lesions. Of these 49, 14 (29%) patients presented with symptomatic lesions, primarily manifesting as bone pain at the lesion site (n=6), or pathologic fracture at the lesion site (n=9). Bone biopsy (n=7) revealed thin trabeculae and extensive vascular proliferation at the lesion site. Bone marrow biopsies (n=2) and imaging (n=20) revealed normal hematopoietic marrow with a marked reduction in marrow fat. 12 patients underwent serial bone imaging revealing diffuse osteosclerosis and the absence of lytic lesions in early childhood. During adolescence, lytic lesions appeared and progressed throughout the proximal and distal ends of the long bones in the appendicular skeleton sparing the axial skeleton. Markers of bone turnover were within normal limits except for sclerostin, which was elevated in a cohort of 11 patients. High BMD (n= 65), advanced skeletal maturation (n= 49), diffuse osteosclerosis (n=30), scoliosis (n=8), pseudo-osteopoikilosis (n=6), coxa valga (n=5), enlarged epiphyses (n=7), and coarse trabeculae (n=8) were also reported. While leptin replacement therapy improved metabolic parameters in many patients, it did not reverse the high bone mineral density or significantly alter markers of bone turnover. Individuals with CGL exhibit a spectrum of skeletal abnormalities including lytic-appearing lesions, osteosclerosis, high bone mineral density, advanced skeletal maturation, and pseudo-osteopoikilosis. Further long-term follow-up is needed to comprehensively assess the progression of these lesions over the life course and to elucidate the mechanisms contributing to their development. Presentation: 6/2/2024

7762 A Unique Case Of Sepsis-Driven Bilateral Adrenal Hemorrhages In A Patient With HIT

Abstract Disclosure: A. Siddiqui: None. B. Shalit: None. H. Nadeem: None. Z. Khan: None. D. Pinkhasova: None. Introduction: Bilateral adrenal hemorrhages, commonly seen in the setting of sepsis as Waterhouse Friderichsen syndrome, is a rare life-threatening condition. This process is driven by the release of bacterial endotoxins leading to the activation of coagulation, fibrinolysis, and proinflammatory pathways. It is by a similar process that now non-septic hypercoagulable states, including heparin-induced thrombocytopenia (HIT), factor V Leiden and protein C resistance are also being recognized as etiologic for bilateral adrenal hemorrhaging. The following case demonstrates a combination of the two etiologies leading to adrenal insufficiency from bilateral adrenal hemorrhages. Clinical Case: A 48-year-old male presented to the emergency department with right upper quadrant pain, dyspnea, and a low-grade fever. Laboratory results indicated leukocytosis with a predominance of neutrophils. Initial computed tomography imaging revealed a 4 x 3.5 cm right lower lobe multi-loculated lung abscess and multiple right lower lobe segmental/subsegmental pulmonary emboli. The patient was started on a heparin drip and empiric antibiotics. Infectious disease was consulted to help determine the etiology of the lung abscess. Extensive workup including sputum, blood, fungal cultures, and acid-fast bacillus smear testing were negative. The patient improved on routine broad-spectrum antibiotics and was planned to be transitioned to a direct oral anticoagulant until serial imaging revealed incidental bilateral 4 cm adrenal hemorrhages. Endocrinology was emergently consulted; a random cortisol level was drawn and found to be low at 2.7 (3-17 µg/dL) with an elevated Adrenocorticotropic hormone (ACTH) level of 114 (6 - 50 pg/mL) indicative of primary adrenal insufficiency. The patient subsequently became hypotensive and was started on stress-dose steroids. Upon further investigation, the patient was found to be thrombocytopenic, and hematology was involved. Based on his 4T score of 5, concern was raised for HIT and argatroban was initiated. Moreover, the patient was eventually stabilized for discharge with close follow-ups with endocrinology, infectious disease, and hematology as an outpatient. Conclusion: There have been 17 reported cases of bilateral adrenal hemorrhaging in the setting of HIT uniformly presenting with complete hemodynamic collapse. This case serves as even more unique given the added component of sepsis. Both sepsis and HIT respectively have been well established to pose individual risk for developing bilateral adrenal hemorrhages. Hence, we hope to highlight the importance of exploring all potential causes of adrenal insufficiency in the setting of bilateral adrenal hemorrhaging and emphasize the harms of anchoring to a single etiology. Presentation: 6/3/2024

A phenological-knowledge-independent method for automatic paddy rice mapping with time series of polarimetric SAR images

Paddy rice, which sustains more than half of the global population, requires accurate and efficient mapping to ensure food security. Synthetic aperture radar (SAR) has become indispensable in this process due to its remarkable ability to operate effectively in adverse weather conditions and its sensitivity to paddy rice growth. Phenological-knowledge-based (PKB) methods have been commonly employed in conjunction with time series of SAR images for paddy rice mapping, primarily because they eliminate the need for training datasets. However, PKB methods possess inherent limitations, primarily stemming from their reliance on precise phenological information regarding paddy rice growth. This information varies across regions and paddy rice varieties, making it challenging to use PKB methods effectively on a large spatial scale, such as the national or global scale, where collecting comprehensive phenological data becomes impractical. Moreover, variations in farming practices and field conditions can lead to differences in paddy rice growth stages even within the same region. Using a generalized set of phenological knowledge in PKB methods may not be suitable for all paddy fields, potentially resulting in errors in paddy rice extraction. To address the challenges posed by PKB methods, this study proposed an innovative approach known as the phenological-knowledge-independent (PKI) method for mapping paddy rice using time series of Sentinel-1 SAR images. The central innovation of the PKI method lies in its capability to map paddy rice without relying on specific knowledge of paddy rice phenology or the need for a training dataset. This was made possible by the incorporation of three novel metrics: VH and VV normalized maximum temporal changes (NMTC) and VH temporal mean, derived from the distinctions between paddy rice and other land cover types in time series of SAR images. The PKI method was rigorously evaluated across three regions in China, each featuring different paddy rice varieties. Additionally, the PKI method was compared with two prevalent phenological-knowledge-based techniques: the automated paddy rice mapping method using SAR flooding signals (ARM-SARFS) and the manual interpretation of unsupervised clustering results (MI-UCR). The PKI method achieved an average overall accuracy of 97.99%, surpassing the ARM-SARFS, which recorded an accuracy of 89.65% due to errors stemming from phenological disparities among different paddy fields. Furthermore, the PKI method delivered results on par with the MI-UCR, which relied on the fusion of SAR and optical image time series, achieving an accuracy of 97.71%. As demonstrated by these findings, the PKI method proves highly effective in mapping paddy rice across diverse regions, all without the need for phenological knowledge or a training dataset. Consequently, it holds substantial promise for efficiently mapping paddy rice on a large spatial scale. The source code used in this study is available at https://code.earthengine.google.com/f82cf10cad64fa3f971ae99027001a6e.