Positive Scan Research Articles

Numerical simulation and morphological analysis of laser cladded 316L stainless steel on inclined substrates

Laser cladding has been mostly studied based on the horizontal substrate state, but the component surface to be repaired is often complex in actual restoration process. Inclined substrate repair is the basis for studying complex surface repair. In this study, 316L stainless steel powder was taken as the research object. The simulation and experimental verification combined method was adopted to study the morphology of single-track and multi-track overlap on the inclined substrate. The main research contents were as follows: Through the simulation model, the molten pool flow and final cladding layer morphology under different scanning paths of laser cladding on the inclined substrate were analyzed. The results showed that when the inclination angle was less than 90°, the change of the cladding layer morphology had regularity. When the inclination angle was greater than 90°, splashing and dripping occurred in the molten pool under several scanning paths, and the cladding layer morphology was highly unstable. Excessively large inclination angle was not suitable for coaxial powder feeding. Neither positive nor negative y-direction scanning overlap cladding layer was horizontal under inclined posture. The cladding layer morphology with x-positive scanning and y-negative overlap was the most stable. An inclined cladding model considering the inclination factor was established in this study, which provided theoretical guidance and predictive analysis for laser cladding on the inclined substrate. Contributions were made to process optimization, path optimization and improvement of cladding layer quality for inclined substrate cladding in the future.

Impact of Clinical Factors on 18F-Flotufolastat Detection Rates in Men With Recurrent Prostate Cancer: Exploratory Analysis of the Phase 3 SPOTLIGHT Study

18F-Flotufolastat (18F-rhPSMA-7.3) is a newly approved prostate-specific membrane antigen targeting radiopharmaceutical for diagnostic imaging of prostate cancer (PCa). SPOTLIGHT (National Clinical Trials 04186845) evaluated 18F-flotufolastat in men with suspected PCa recurrence. Here, we present results of predefined exploratory endpoints from SPOTLIGHT to evaluate the impact of clinical factors on 18F-flotufolastat detection rates (DR). The impact of baseline prostate-specific antigen (PSA), PSA doubling time (PSAdt), and International Society of Urologic Pathology Grade Group (GG) on 18F-flotufolastat DR was evaluated among all SPOTLIGHT patients with an evaluable scan, with DR stratified according to the patients' prior treatment (radical prostatectomy ± radiation therapy [RP] or radiation therapy only [RT]). The patients underwent positron emission tomography 50 to 70 minutes after receiving 18F-flotufolastat (296 MBq IV), and scans were read by 3 blinded central readers, with the majority read representing agreement between ≥2 readers. In total, 389 men (median PSA: 1.10 ng/mL) were evaluable. By majority read, 18F-flotufolastat identified distant lesions in 39% and 43% of patients treated with prior RP or RT, respectively. The overall DR broadly increased with increasing PSA (<0.2 ng/mL: 33%; ≥10 ng/mL: 100%). Among patients with PSA <1 ng/mL, 68% had positive scans, and 27% had extrapelvic findings. PSAdt was available for 145/389 (37%) patients. PSAdt did not appear to influence 18F-flotufolastat DR (77%-90% across all PSAdt categories). Among patients with prior RP, DR ranged from 70% to 83% across PSAdt categories, and 100% DR was reported for all post-RT patients. In total, 362/389 (93%) patients had baseline GG data. Overall DRs were uniformly high (75%‒95%) across all GG. When stratified by prior treatment, DRs across all GG were 69% to 89% in patients with prior RP and ≥96% in patients with prior RT. 18F-Flotufolastat-positron emission tomography enabled the accurate detection of recurrent PCa lesions across a wide range of PSA, PSAdt, and International Society of Urologic Pathology GG, thus supporting its clinical utility for a broad range of patients with recurrent PCa.

APOE4 homozygozity represents a distinct genetic form of Alzheimer's disease.

This study aimed to evaluate the impact of APOE4 homozygosity on Alzheimer's disease (AD) by examining its clinical, pathological and biomarker changes to see whether APOE4 homozygotes constitute a distinct, genetically determined form of AD. Data from the National Alzheimer's Coordinating Center and five large cohorts with AD biomarkers were analyzed. The analysis included 3,297 individuals for the pathological study and 10,039 for the clinical study. Findings revealed that almost all APOE4 homozygotes exhibited AD pathology and had significantly higher levels of AD biomarkers from age 55 compared to APOE3 homozygotes. By age 65, nearly all had abnormal amyloid levels in cerebrospinal fluid, and 75% had positive amyloid scans, with the prevalence of these markers increasing with age, indicating near-full penetrance of AD biology in APOE4 homozygotes. The age of symptom onset was earlier in APOE4 homozygotes at 65.1, with a narrower 95% prediction interval than APOE3 homozygotes. The predictability of symptom onset and the sequence of biomarker changes in APOE4 homozygotes mirrored those in autosomal dominant AD and Down syndrome. However, in the dementia stage, there were no differences in amyloid or tau positron emission tomography across haplotypes, despite earlier clinical and biomarker changes. The study concludes that APOE4 homozygotes represent a genetic form of AD, suggesting the need for individualized prevention strategies, clinical trials and treatments.

EANM consensus document on the use of [18F]FDG PET/CT in fever and inflammation of unknown origin

PurposePatients with fever and inflammation of unknown origin (FUO/IUO) are clinically challenging due to variable clinical presentations with nonspecific symptoms and many differential diagnoses. Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) is increasingly used in FUO and IUO, but the optimal diagnostic strategy remains controversial. This consensus document aims to assist clinicians and nuclear medicine specialists in the appropriate use of [18F]FDG-PET/CT in FUO and IUO based on current evidence.MethodsA working group created by the EANM infection and inflammation committee performed a systematic literature search based on PICOs with “patients with FUO/IUO” as population, “[18F]FDG-PET/CT” as intervention, and several outcomes including pre-scan characteristics, scan protocol, diagnostic yield, impact on management, prognosis, and cost-effectiveness.ResultsWe included 68 articles published from 2001 to 2023: 9 systematic reviews, 49 original papers on general adult populations, and 10 original papers on specific populations. All papers were analysed and included in the evidence-based recommendations.ConclusionFUO and IUO remains a clinical challenge and [18F]FDG PET/CT has a definite role in the diagnostic pathway with an overall diagnostic yield or helpfulness in 50–60% of patients. A positive scan is often contributory by directly guiding treatment or subsequent diagnostic procedure. However, a negative scan may be equally important by excluding focal disease and predicting a favorable prognosis. Similar results are obtained in specific populations such as ICU-patients, children and HIV-patients.

Spatial-Potential-Color-Resolved Bipolar Electrode Electrochemiluminescence Biosensor Using a CuMoOx Electrocatalyst for the Simultaneous Detection and Imaging of Tetracycline and Lincomycin.

A spatial-potential-color-resolved bipolar electrode electrochemiluminescence biosensor (BPE-ECL) using a CuMoOx electrocatalyst was constructed for the simultaneous detection and imaging of tetracycline (TET) and lincomycin (LIN). HOF-101 emitted peacock blue light under positive potential scanning, and CdSe quantum dots (QDs) emitted green light under negative potential scanning. CuMoOx could catalyze the electrochemical reduction of H2O2 to greatly increase the Faradic current of BPE and realize the ECL signal amplification. In channel 1, CuMoOx-Aptamer II (TET) probes were introduced into the BPE hole (left groove A) by the dual aptamer sandwich method of TET. During positive potential scanning, the polarity of BPE (left groove A) was negative, resulting in the electrochemical reduction of H2O2 catalyzed by CuMoOx, and the ECL signal of HOF-101 was enhanced for detecting TET. In channel 2, CuMoOx-Aptamer (LIN) probes were adsorbed on the MXene of the driving electrode (DVE) hole (left groove B) by hydrogen-bonding and metal-chelating interactions. LIN bound with its aptamers, causing CuMoOx to fall off. During negative potential scanning, the polarity of DVE (left groove B) was negative and the Faradic current decreased. The ECL signal of CdSe QDs was reduced for detecting LIN. Furthermore, a portable mobile phone imaging platform was built for the colorimetric (CL) detection of TET and LIN. Thus, the multiple mode-resolved detection of TET and LIN could be realized simultaneously with only one potential scan, which greatly improved detection accuracy and efficiency. This study opened a new technology of BPE-ECL sensor application and is expected to shine in microchips and point-of-care testing (POCT).

OA07 Is the SPADE tool a suitable way of screening patients for possible axial spondyloarthropathy

Abstract Background/Aims There are often significant delays to the diagnosis of axial spondyloarthritis (AxSpA). The imaging modality of choice to investigate for AxSpA is an MRI with a specific AxSpA protocol (MRI AS protocol). A common route of referral for MRI scans looking for AxSpA is via the community physiotherapy team. The Spondyloarthritis Diagnosis Evaluation (SPADE) tool has been designed to estimate the probability of patients having AxSpA. This study aimed to look at the relationship between SPADE tool probability score and MRI AS protocol results in patients who were referred from community physiotherapy. Methods This was a retrospective service evaluation. The sample was obtained from 200 MRI AS protocol requests between 6 January 2020 and 15 December 2021. For each patient, the MRI result was obtained from ICE electronic results software. MRI results were categorised as AxSpA, not AxSpA, or equivocal. For equivocal results, electronic patient notes were reviewed to identify whether patients went on to be diagnosed with AxSpA. The patient SPADE score (improbable, additional tests necessary, probable diagnosis, or definite diagnosis) was recorded for each patient. Information was obtained from the electronic physiotherapy notes to determine a SPADE score. Results Of the 200 scans requested, 21 scans were excluded (eight due to AS protocol not being performed; six due to duplicate requests; four not investigating for AxSpA; two where radiology had suggested MRI AS protocol; one patient awaiting recall for a repeat scan). Of the 179 patients who had MRI scans, 9.5% (n = 17) showed AxSpA, 8.9% were equivocal (n = 16) and 81.6% (n = 146) were negative. A SPADE score was determined for 177 patients (two had insufficient data to determine a score). 30% (n = 53) of patients were ‘improbable’, 56% (n = 99) were ‘additional tests necessary’, 8% (n = 14) were ‘probable’ and 6% (n = 11) were ‘definite’. Of the ‘improbable’ cases, three had MRI demonstrating AxSpA and one was equivocal (4/53 [7.5%]). 49 patients had no MRI evidence of AxSpA. Of the patients with MRI positive scans, 3/17 (17.6%) were ‘improbable’ using the SPADE tool. Conclusion Having a tool to screen patients in the community may help to better identify those who warrant further investigation for AxSpA. The SPADE tool may be a useful aid to identify who to refer for further investigation of inflammatory back pain. Many patients identified as ‘improbable’ by the SPADE tool did not have evidence of AxSpA. If the tool was applied prospectively, this may lead to large reduction in the number of MRI AS protocol scans performed. However, there were a small number of ‘improbable’ cases who had MRI evidence of AxSpA and could therefore be misdiagnosed as non-inflammatory back pain. Disclosure T. Nadin: None. S. Crompton: None. A. Chopra: None. N. Kotnis: None. L. Dunkley: Honoraria; Abbvie, UCB, Pfizer and Novartis. Other; Speakers fees from Abbvie, UCB, Pfizer and Novartis.

Factors Contributing to the Accuracy of PET Scans in Detecting Cancer Metastases in Cairo Hospitals, Egypt

Introduction: Positron emission tomography (PET) has become an important diagnostic tool in oncology, providing metabolic information that can aid in the detection and evaluation of cancer. However, the accuracy of PET scans in detecting cancer metastases can be influenced by various factors, including the type of cancer, location of metastases, and image acquisition protocol. This study aims to evaluate the factors that influence the accuracy of PET scans in detecting cancer metastases in patients at Cairo Hospital, Egypt.&#x0D; Methods: Patient data were collected retrospectively. A total of 5000 research subjects participated in this study. Data were analyzed to identify factors associated with false-positive or false-negative PET scan results.&#x0D; Results: Patients with lung or colorectal cancer were 2.45 times more likely to experience accurate positive PET scan results than patients with other types of cancer. Patients with metastases in lymph nodes were 1.93 times more likely to experience accurate positive PET scan results than patients with metastases in solid organs. Patients with a long PET scan image acquisition protocol were 1.78 times more likely to experience accurate positive PET scan results than patients with a short image acquisition protocol.&#x0D; Conclusion: PET scan is a valuable diagnostic tool in oncology, but its accuracy in detecting cancer metastases can be influenced by various factors. These factors should be considered when interpreting PET scan results and to improve cancer diagnosis and management.

The influence of antenatal imaging on prenatal bonding in uncomplicated pregnancies: a mixed methods analysis

BackgroundPrenatal bonding describes the emotional connection expectant parents form to their unborn child. Research acknowledges the association between antenatal imaging and enhanced bonding, but the influencing factors are not well understood, particularly for fathers or when using advanced techniques like fetal magnetic resonance imaging (MRI). This study aimed to identify variables which may predict increased bonding after imaging.MethodsFirst-time expectant parents (mothers = 58, fathers = 18) completed a two-part questionnaire (QualtricsXM™) about their expectations and experiences of ultrasound (n = 64) or fetal MRI (n = 12) scans in uncomplicated pregnancies. A modified version of the Prenatal Attachment Inventory (PAI) was used to measure bonding. Qualitative data were collected through open-ended questions. Multivariate linear regression models were used to identify significant parent and imaging predictors for bonding. Qualitative content analysis of free-text responses was conducted to further understand the predictors’ influences.ResultsBonding scores were significantly increased after imaging for mothers and fathers (p < 0.05). MRI-parents reported significantly higher bonding than ultrasound-parents (p = 0.02). In the first regression model of parent factors (adjusted R2 = 0.17, F = 2.88, p < 0.01), employment status (β = -0.38, p < 0.05) was a significant predictor for bonding post-imaging. The second model of imaging factors (adjusted R2 = 0.19, F = 3.85, p < 0.01) showed imaging modality (β = -0.53), imaging experience (β = 0.42) and parental excitement after the scan (β = 0.29) were significantly (p < 0.05) associated with increased bonding. Seventeen coded themes were generated from the qualitative content analysis, describing how scans offered reassurance about fetal wellbeing and the opportunity to connect with the baby through quality interactions with imaging professionals. A positive scan experience helped parents to feel excited about parenthood. Fetal MRI was considered a superior modality to ultrasound.ConclusionsAntenatal imaging provides reassurance of fetal development which affirms parents’ emotional investment in the pregnancy and supports the growing connection. Imaging professionals are uniquely positioned to provide parent-centred experiences which may enhance parental excitement and facilitate bonding.

Theoretical and experimental study on the effect of scanning speed on FAIMS peaks

High-Field Asymmetric Ion Mobility Spectrometry (FAIMS) is a technique for ion separation and detection based on ion mobility variation under high electronic field. While compensation voltage scanning speed is a fundamental parameter in FAIMS, its impact on spectra remains unclear. In this work, a function referred to as F-EMG is introduced to describe the impact of compensation voltage scanning speed on FAIMS spectra, and the properties of the function are studied. Theoretical analysis emphasizes the impact of the scanning speed on peak height, position, and symmetry, as well as the capability of the F-EMG function to progressively approach Gaussian function at lower scanning speeds. Furthermore, the function indicates that spectra obtained in positive and negative scanning modes exhibits symmetry. An experimental validation, conducted with a custom FAIMS setup and analyzing hydrogen sulfide, ethylbenzene, toluene, styrene, benzene and ammonia, confirms the model's influence on peak features, fitting accuracy, and exhibits a closer alignment with the Gaussian function at lower scanning speeds. Additionally, the experimental data indicate that the spectra show symmetry in positive and negative scanning models. This work not only improves understanding of FAIMS spectral analysis but also introduces a robust method for enhancing data accuracy across varying scanning speeds.

Validation of Patient Intrinsic Factors on Pre-Delay Coronary CT Scan Angiography (Coronary CTA) Bolus Tracking

Background: There is a variation in the pre-delay scan time on the Caronaria CTA tracking bolus examination, which give a constitution against the acquisition time and the contrast.Purpose: This study aims to determine the influence’s intrinsic factors on the pre-delay scan time.Method: Analytical research with a retrospective approach’s cross-sectional design measures independent variables: aortic diameter, systolic blood pressure, age, heart rate (HR), urea, creatinine, and body mass index (BMI). The dependent variables: the time pre-delay scan is performed simultaneously; its properties are momentary and observed under current conditions. Each object was observed three times, then the data normality and influence relationships between variables were analyzed with the bivariate and multivariate analysis approaches. Data was surveyed in June–August 2023 at a Hospital in Jakarta.Results: Bivariate analysis showed a significant relationship between aortic diameter and pre-delay scan time with a value r = 0,577, having a positive pattern, as well as having a dependency 33.3% with p = 0,000 significance. While a very strong relationship is indicated by systolic blood pressure with r = 0.534 value and positive patterns, has a dependence of 30.4% with p = 0.000 significance value. Other instrumental factors: creatinine and BMI have a moderate relationship with r = 0.308 and r = 0.338 and are positive with a determination coefficient of 0.095 and 0.115. Urea, age, and heart rate have r = 0.174, 0.200, and 0.116. The determination coefficient values are under 0.04.Conclusion: The intrinsic factors: aortic diameter, systolic pressure, creatinine, urea, age, and heart rate have influenced positive CTA scan delays although different determination coefficients.Keywords: CTA Coronarya, bolus tracking, pre-delay scan time, aortic diameter, systolic blood pressure.

Optimizing the indication of initial radioiodine oncolytic treatment for metastatic differentiated thyroid cancer by diagnostic 131I scan

As a classic theranostic radiopharmaceutical, radioiodine (131I) has been utilized in the management of differentiated thyroid cancer (DTC) for more than 8 decades, and the refinement of its clinical practice has been raised recently. This study was conducted to evaluate the efficiency of a diagnostic (Dx) 131I scan in optimizing the indication of initial radioiodine oncolytic treatment (ROT) for metastatic DTC by predicting therapeutic outcomes. A total of 100 patients (Dx positive, n=29; Dx negative, n=71) were eligible for patient-based analysis. The matching rate was 83.0% between the Dx and the post-therapeutic scans (kappa=0.648, P<0.001). The biochemical remission rate and structural shrinkage rate induced by the initial ROT in the Dx-positive group were, respectively, greater than those in the Dx-negative group (83.3% vs. 17.4%, P<0.001; 37.9% vs. 4.2%, P<0.001). Notably, the predictive values of positive Dx scans for ROT responsiveness and negative Dx scans for ROT nonresponsiveness reached up to 89.7% and 84.5%, respectively. This Dx scan approach seems viable in characterizing the 131I-avidity of metastatic DTC and plays a pivotal role in optimizing the indication of initial ROT for metastatic DTC.

Whole-body tumour burden on [18F]DCFPyL PET/CT in biochemical recurrence of prostate cancer: association with tumour biology and PSA kinetics.

The objective was to assess the association between molecular imaging (mi) variables on [18F]DCFPyL-PET/CT with clinical and disease characteristics and prostate specific antigen (PSA) related variables in patients with biochemical recurrence of prostate cancer (BRPC). We analysed patients with BRPC after radical treatment. We obtained clinical and PSA variables: International Society of Urology Pathology (ISUP) grade group, European Association of Urology (EAU) risk classification, PSA (PSA≤1ng/ml, 1<PSA≤2, PSA>2), PSA doubling time (PSAdt) and PSA velocity (PSAvel). All PET/CT scans were reviewed with the assistance of automated Prostate Molecular Imaging Standardized Evaluation (aPROMISE) software and lesions' segmentation in positive scans was performed using this platform. Standardized uptake value (SUV) derived variables; tumour burden variables [whole-body tumour volume (wbTV), whole-body tumour lesion activity (wbTLA) and whole-body mi PSMA (wbPSMA)] and miTNM staging were obtained. Cut-off of PSA and kinetics able to predict PET/CT results were obtained. Associations between disease and mi variables were analysed using ANOVA, Kruskal-Wallis and Spearman's correlation tests. Multivariate analysis was also performed. Two hundred and seventy-five patients were studied. [18F]DCFPyL-PET/CT were positive in 165/275 patients. In multivariate analysis, moment of biochemical recurrence, ISUP group, PSA level and PSAvel showed significant association with the detection rate. miTNM showed significant association with PSA level (p<0.001) and kinetics (p<0.001), being higher in patients with metastatic disease. Both PSA and PSAvel showed moderate correlation with wbTV, wbTLA and wbPSMA (p<0.001). A weak correlation with SUVs was found. Mean wbTV, wbTLA and wbPSMA values were significantly higher in PSA > 2ng/ml, PSAdt ≤ 6 months and PSAvel ≥ 0.2ng/ml/month groups. Also, wbTV (p=0.039) and wbPSMA (p=0.020) were significantly higher in patients with ISUP grade group 5. PSA and PSAvel cut-offs (1.15 ng/ml and 0.065 ng/ml/month) were significantly associated with a positive PET/CT. Higher PSA values, unfavourable PSA kinetics and ISUP grade group 5 were robust predictive variables of larger tumour burden variables on [18F]DCFPyL PET/CT assessed by aPROMISE platform.

Performance of a fast-track pathway for giant cell arteritis in Waikato, Aotearoa New Zealand.

Giant cell arteritis (GCA) is the most common primary vasculitis in adults over 50 years of age. To facilitate early diagnosis and reduce harms from corticosteroids and temporal artery biopsies, fast-track pathways have been established. We review the benefits of the fast-track pathway set up in Waikato, Aotearoa New Zealand. Patients were collected prospectively as part of the fast-track pathway from 2014 to 2022. Their records were then reviewed retrospectively to collect data on clinical features, investigations and treatment. There were 648 individual patients over the study period who had a colour Doppler ultrasound (CDUS) of the temporal arteries. There were 17 true positive CDUS, giving a sensitivity of 10.3% (95% confidence interval [CI] 6.3-15.5%) and specificity of 99.8% (95% CI 99.1-100%). Patients with GCA and a positive scan had significantly fewer steroids than those with GCA and a negative scan (p=0.0037). There were 376 patients discharged after a CDUS who did not have a diagnosis of GCA, resulting in reduced corticosteroid and temporal artery biopsy exposure. This is a real-life study that reflects the benefits of fast-track pathways in Aotearoa New Zealand to patients and healthcare systems. It also shows the effect of corticosteroids on positive CDUS, an important consideration when setting up an fast-track pathway.

Abstract 1071: Circulation of rare events in the liquid biopsy for early detection of lung mass lesions

Abstract Lung cancer screening with low-dose CT scans (LDCT) has reduced mortality for patients with high-risk smoking histories. However, this method of screening remains imperfect. High rates of false positive scans expose patients to additional morbidity as they pursue subsequent diagnostic evaluation. Real-world application of screening LDCT remains low. Finally, current screening guidelines exclude those without smoking histories, a population which comprises up to a quarter of lung cancer patients. We sought to explore the utility of liquid biopsy (LBx) in lung cancer patients and its use in early cancer screening and diagnosis. Using the third generation High-Definition Single Cell Assay (HDSCA3.0) workflow, we analyzed 99 peripheral blood samples divided into three cohorts: Normal Donors (ND, n=50) who were healthy volunteers with no known pathology, Screening CT patients (CT, n=25) who underwent standard LDCT screening with resultant Lung-RADS 1-2, Biopsy patients (BX, n=24) who had abnormal CT scans requiring tissue biopsy. The ND group was used to characterize baseline epithelial, mesenchymal, endothelial, and immune cells, alongside acellular events (oncosomes). For the CT and BX patients, demographic information including age, gender, and average BMI was roughly equivalent, however average pack-years smoked differed owing to 10 (42%) patients in the BX group who had no prior smoking history. A total of 14 (58%) BX patients were diagnosed with primary lung cancer (BX+), of which 11(75%) were adenocarcinoma, 2 (19%) were squamous cell carcinoma and 1 (6%) was small cell. Across the cohorts we observed intra- and interpatient heterogeneity of rare events including multiple phenotypic rare cell populations and oncosomes. The comparison of the rare event enumerations between the ND, CT, BX+, and BX- cohorts revealed a greater incidence of total events, total rare cells and oncosomes, as well as specific cellular phenotypes in the CT and BX cohorts compared to the ND cohort. LBx analytes were detected at a significant elevation in the BX samples compared to the CT samples, but there was no significant difference between BX+ and BX- samples. The data supports the utility of the LBx in distinguishing patients with an alveolar mass lesion from those without, providing a mechanism for screening prior to LDCT to better inform clinical workup and avoid unnecessary radiation exposure and biopsy. Citation Format: Anya Shah, Karen Resnick, Jeremy Mason, Peter Kuhn, Jorge Nieva, Stephanie Shishido. Circulation of rare events in the liquid biopsy for early detection of lung mass lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1071.

Association between vascular FDG uptake during follow-up and the development of thoracic aortic aneurysms in giant cell arteritis.

A positive PET scan at diagnosis was associated with a greater yearly increase in ascending and descending aortic diameter and thoracic aortic volume in patients with giant cell arteritis (GCA). Radiologic and histopathologic vascular abnormalities persist in a subset of treated patients despite clinical remission. The aim of this study was to evaluate the association between vascular FDG uptake during follow-up and the development of thoracic aortic aneurysms. We recently performed a prospective cohort study of 106 GCA patients, who underwent FDG PET and CT imaging at diagnosis and CT imaging yearly for a maximum of 10 years. In this post hoc analysis, GCA patients who also have had FDG PET imaging during follow-up were included. PET scans were visually scored (0-3) at 7 vascular areas. PET scans were considered positive in case of FDG uptake ≥grade 2 in any large vessel. Eighty-eight repeat PET scans were performed in 52 out of 106 GCA patients, who were included in the original prospective cohort. Fifty-five (63%) PET scans were done at the time of a relapse and 33 (38%) were done while in remission. Nine out of ten patients with an incident thoracic aortic aneurysm had both a positive PET scan at diagnosis and during follow-up. In addition to the intensity and extent of the initial vascular inflammation, ongoing aortic inflammation may contribute to the development of thoracic aortic aneurysms in GCA. However, this hypothesis should be confirmed in a large prospective trial with repeat PET scans at predefined time points during follow-up.

The Implementation of Physiotherapist-Led Lung Ultrasound on Physiotherapy and Medical Clinical Decision-Making in Intensive Care Patients: A Retrospective Review

Purpose: The clinical use of lung ultrasound (LUS) is gaining acceptance and rapidly growing. Lung ultrasound is being integrated into clinical care by trained respiratory physiotherapists and has been reported to influence physiotherapists' clinical decision-making in the respiratory management of patients. The purpose of this study was to evaluate the implementation of physiotherapist-led LUS on physiotherapy and medical clinical decision-making in a single intensive care unit (ICU). Methods: This was a retrospective review using descriptive analyses of a senior ICU physiotherapist's LUS scans. Results: Of the 40 LUS scans completed, 26 (65%) were clinically indicated, and 31 (77.5%) were identified as positive scans. After LUS, respiratory physiotherapy management changed in 11 (27.5%) cases, continued unaltered in 12 (30%) cases, deemed not indicated in 4 (10%) cases, and not reported in 10 (25%) cases. Medical decision-making changed in 8 (20%) cases, continued unchanged in 14 (35%) cases, and not reported in 18 (45%) cases. Conclusions: This small retrospective review of a single physiotherapist's LUS scans suggests that LUS may have an influence on physiotherapy and medical clinical management in ICU. Research to prospectively evaluate the impact of physiotherapy-led LUS on clinical decision-making and key patient outcomes is strongly recommended.

Subclinical atherosclerosis in young adults predicting cardiovascular disease: The Cardiovascular Risk in Young Finns Study

Background and aimsAtherosclerosis is accompanied by pre-clinical vascular changes that can be detected using ultrasound imaging. We examined the value of such pre-clinical features in identifying young adults who are at risk of developing atherosclerotic cardiovascular disease (ASCVD). MethodsA total of 2641 individuals free of ASCVD were examined at the mean age of 32 years (range 24–45 years) for carotid artery intima-media thickness (IMT) and carotid plaques, carotid artery elasticity, and brachial artery flow-mediated endothelium-dependent vasodilation (FMD). The average follow-up time to event/censoring was 16 years (range 1–17 years). ResultsSixty-seven individuals developed ASCVD (incidence 2.5%). The lowest incidence (1.1%) was observed among those who were estimated of having low risk according to the SCORE2 risk algorithm (<2.5% 10-year risk) and who did not have plaque or high IMT (upper decile). The highest incidence (11.0%) was among those who were estimated of having a high risk (≥2.5% 10-year risk) and had positive ultrasound scan for carotid plaque and/or high IMT (upper decile). Carotid plaque and high IMT remained independently associated with higher risk in multivariate models. The distributions of carotid elasticity indices and brachial FMD did not differ between cases and non-cases. ConclusionsScreening for carotid plaque and high IMT in young adults may help identify individuals at high risk for future ASCVD.

Prevalence of transthyretin cardiac amyloidosis in patients with high-degree AV block

ObjectiveTransthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative cardiac disorder caused by deposition of wild type or mutated transthyretin. As ATTR-CM is associated with conduction disease, we sought to determine its...

MRI findings of peroneal tendon tears do not necessarily correlate to clinical findings in paediatric and adolescent patients.

Pathologic abnormality of the peroneal tendons are thought to be an under-appreciated source of vague ankle and hindfoot pain in paediatric patients, partly because they can be difficult to diagnose and differentiate from lateral ankle ligament injuries. While magnetic resonance imaging (MRI) is the primary imaging modality used to detect peroneal tendon pathology, previous studies in adults have found that positive MRIs demonstrate a positive predictive value (PPV) of associated clinical findings around 48%. There are no similar known published studies in the paediatric population. Our objective was to determine the positive predictive value of peroneal tendon pathology as diagnosed by MRI as related to positive clinical exam findings in the paediatric and adolescent population. This IRB approved retrospective study was conducted at a tertiary children's hospital. Inclusion criteria included patients under 18years from our tertiary care institution with (a) ankle MRI findings indicating pathology of the peroneus brevis/longus tendons confirmed by a board certified paediatric musculoskeletal radiologist and (b) formal review of the clinical examination by a fellowship trained paediatric orthopaedic surgeon. Patients with congenital deformities or previous surgical intervention of the lateral ankle were excluded. Forty-seven patients (with 48 MRIs) met inclusion criteria over a tenyear period. The majority of the positive MRI scans (70%) demonstrated a peroneus brevis split tear. Of the patients with positive findings on MRI, 17 patients had an associated positive clinical exam. The positive predictive value of MRI for peroneal tendon tears with positive clinical findings was 35.41% (95% confidence interval = 31.1% to 41.6%). There were 31 patients with MRI positive findings with a negative clinical exam. Despite having a negative clinical exam, a high percentage of patients had positive MRI findings suggestive of peroneal tendon pathology which confirms findings of adult populations demonstrating a high rate of incidental finding of peroneal tendon pathology on MRI in paediatric patients.

Straightforward method for the electrochemical identification of dopamine in the presence of uric acid and ascorbic acid

A few-layer graphene/Pt (FGP) electrode and a novel electrochemical technique were used in determining dopamine and simultaneously detecting uric acid (UA), ascorbic acid (AA), and dopamine (DA) in a buffered phosphate-saline solution at pH 7.4. The FGP electrode effectively separated the oxidation peaks of UA, DA, and AA in the positive scan. Interestingly, during the negative scan, the FGP electrode selectively responded to DA while showing negligible response to UA and AA, thus allowing the accurate quantification of small amounts of DA in the presence of considerable UA and AA interferences. The sensors for AA, DA, and UA exhibited successful detection in the positive scan. The linear ranges were 10–1800 (AA), 1–300 (DA), and 5–800 (UA) µM, the sensitivity was 109.27 (AA), 754.19 (DA), and 493.03 (UA) µA cm–2 mM–1, and the detection limits were 4.2 µM (AA), 0.42 µM (DA), and 2.2 µM (UA). Furthermore, DA quantification was achieved in the negative scan, demonstrating a linear range of 1–100 µM, sensitivity of 2235.7 µA cm–2 mM–1, and detection limit of 0.14 µM. This study presents a novel and efficient electrochemical technique for the rapid and straightforward detection of dopamine.