Performance Of Diagnostic Tests Research Articles

A prevalence-robust measure of diagnostic test performance

A prevalence-robust measure of diagnostic test performance

Performance of the Bioline™ Malaria Ag Pf/Pan and Bioline™ Malaria Ag Pf/Pv for Malaria Diagnostics: Madagascar In-Country Evaluation.

Malaria remains a significant public health concern in Madagascar. The WHO recommends using parasitological methods to confirm Plasmodium infection before treatment. This study evaluated the performance of two rapid diagnostic tests (RDTs), Bioline™ Malaria Ag Pf/Pan (Abbott Point of Care, Princeton, NJ) and Bioline™ Malaria Ag Pf/Pv (Abbott Point of Care, Princeton, NJ), compared with microscopy and polymerase chain reaction (PCR) as reference methods. A prospective, diagnostic performance study was conducted in two malaria-endemic districts with different epidemiological contexts: Ifanadiana (Plasmodium falciparum [P. falciparum] transmission) and Mandoto (Plasmodium vivax transmission). Symptomatic patients and asymptomatic individuals aged 3-81 years were enrolled between April and July 2023. Finger prick blood samples were used for RDTs, Giemsa-stained blood films, and molecular analysis. Among 675 participants (401 symptomatic, 274 asymptomatic), the performance for detecting P. falciparum and non-falciparum/vivax malaria in symptomatic patients for Bioline™ Malaria Ag Pf/Pan was 96.5% (95% CI: 93.4-98.4%) and 91.5% (95% CI: 82.5-96.8%) sensitivity and 76.0% (95% CI: 64.7-85.1%) specificity, and the performance for Bioline™ Malaria Ag Pf/Pv was 95.0% and 91.5% sensitivity and 76.0% specificity. In asymptomatic individuals, the performance was 90.3% (95% CI: 83.4-95.0%) and 33.3% (95% CI: 4.3-77.7%) sensitivity and 85.4% (95% CI: 78.9-90.6%) specificity for Bioline™ Malaria Ag Pf/Pan and 80.6% (95% CI: 80.1-93.1%) and 0% (95% CI: 0-84.2%) sensitivity and 86.0% (95% CI: 79.7-91.0%) and 86.1% (95% CI: 79.7-91.0%) specificity for Bioline™ Malaria Ag Pf/Pv. Rapid diagnostic test performance varies with local epidemiology in symptomatic patients. The results emphasize the need for careful consideration of RDT use based on local epidemiology and clinical context. Both RDTs could be used when microscopy and PCR are unavailable.

Disentangling the effects of intermittent faecal shedding and imperfect test sensitivity on the microscopy-based detection of gut parasites in stool samples.

Gut-parasite transmission often involves faecal shedding, and detecting parasites in stool samples remains the cornerstone of diagnosis. However, not all samples drawn from infected hosts contain parasites (because of intermittent shedding), and no test can detect the target parasites in 100% of parasite-bearing samples (because of imperfect sensitivity). Disentangling the effects of intermittent shedding and imperfect sensitivity on pathogen detection would help us better understand transmission dynamics, disease epidemiology, and diagnostic-test performance. Using paediatric Giardia infections as a case-study, here we illustrate a hierarchical-modelling approach to separately estimating the probabilities of host-level infection (Ψ); stool-sample-level shedding, given infection (θ); and test-level detection, given infection and shedding (p). We collected 1-3 stool samples, in consecutive weeks, from 276 children. Samples (413 overall) were independently examined, via standard sedimentation/optical microscopy, by a senior parasitologist and a junior, trained student (826 tests overall). Using replicate test results and multilevel hierarchical models, we estimated per-sample Giardia shedding probability at [Formula: see text] and observer-specific test sensitivities at [Formula: see text] and [Formula: see text]. Gender-specific infection-frequency estimates were [Formula: see text] and [Formula: see text]. Had we used a (hypothetical) Perfect Test with 100% narrow-sense sensitivity (pPT = 1.0), the average probability of detecting Giardia in a sample drawn from an infected child (Ψ = 1.0) would have been Pr(d|i,PT) = Ψ×θ×pPT≈1.0×0.44×1.0≈0.44. Because no test can be >100% sensitive, Pr(d|i) (which measures clinical sensitivity) can only be brought above ~ 0.44 by tinkering with the availability of Giardia in stool samples (i.e., θ); for example, drawing-and-pooling 3 replicate samples would yield [Formula: see text]. By allowing separate estimation (and modelling) of pathogen-shedding probabilities, the approach we illustrate provides a means to study pathogen transmission cycles and dynamics in unprecedented detail. Separate estimation (and modelling) of true test sensitivity, moreover, may cast new light on the performance of diagnostic tests and procedures, whether novel or routine-practice.

Sex differences in the association between sarcopenia index and sarcopenia: a cross-sectional study from a Chinese community-based population

Abstract Purpose The sarcopenia index (SI) is a convenient method to screen for sarcopenia, but few studies have analysed whether there are sex differences. The aim of this study was to analyse sex differences in the relationship between SI and sarcopenia in a Chinese community-based population. Methods This cross-sectional study included participants from 2011 China Health and Retirement Longitudinal Study. The SI was defined as 100 × creatinine / cystatin C. Diagnosis of sarcopenia based on the Asian Working Group for Sarcopenia 2019 consensus. Logistic regression model, linear regression model, and natural spline model were used to analyze the association between SI and sarcopenia. Results A total of 7,118 participants with a mean age of 60.6 ± 10.1 were included, 53.4% females. In males, the prevalence of sarcopenia decreased by 25% for every 10 increase in SI, and skeletal muscle mass index (SMI) increased by 0.04, odds ratio (OR), β, and 95% confidence interval (CI) were 0.75 (0.65–0.87), 0.04 (0.02–0.05), both P < 0.001. In females, the SI was not significantly associated with sarcopenia, OR and 95% CI were 0.99 (0.9 ~ 1.08), P = 0.775; for every 10 increase in SI, the SMI in females decreased by 0.03, β and 95% CI were -0.03 (-0.04 ~ -0.01), P = 0.001. Conclusion In the Chinese community, the SI is negatively associated with sarcopenia in males and has moderate diagnostic test performance. It was not associated with sarcopenia in females, and using the SI to screen for sarcopenia in females may not be a reliable method.

Serum GFAP and UCH-L1 for the identification of clinically important traumatic brain injury in children in France: a diagnostic accuracy substudy

Many children with mild traumatic brain injury (mTBI), defined by a Glasgow Coma Scale (GCS) score between 13 and 15, undergo hospitalisation or cranial CT (CCT) scans despite the absence of clinically important traumatic brain injury (ciTBI; ie, hospitalisation >2 days associated with intracranial lesions on CCT, neurosurgical intervention, intensive care admission, or death). Clinical algorithms have reduced CCT scans and hospitalisations by 10%. We aimed to established age-appropriate reference values for GFAP and UCH-L1 and evaluate their diagnostic test performance in identifying ciTBI in children. This study was a diagnostic test accuracy substudy within the PROS100B stepped wedge cluster randomised trial that included children aged 16 years or younger, clinically managed within 3 h of mTBI, with a GCS score of 15 requiring hospitalisation or CCT scan according to French Pediatric Society guidelines (equivalent to the intermediate risk group of the PECARN algorithm). Enrolment for PROS100B occurred from Nov 1, 2016, to Oct 31, 2021, at 11 hospital emergency departments in France. Stored blood samples collected from March 1, 2015, to Oct 31, 2015, from children aged 16 years or younger who were outpatients for allergic conditions unrelated to mTBI and free of neurological disease were used as a control group to calculate reference values of GFAP and UCH-L1 across four age groups (<6 months, 6 months to <2 years, 2 years to <4 years, and 4 years to <16 years). The diagnostic test performance of GFAP and UCH-L1, both above the reference range to identify ciTBI, was evaluated in the children with mTBI. GFAP and UCH-L1 were measured with the Alinity analyser (Abbott, Chicago, IL, USA). Reference values were calculated from GFAP and UCH-L1 measured in samples from 718 control children (378 [53%] boys and 340 [47%] girls). 531 children (334 [63%] boys and 197 [37%] girls) aged 0-16 years with mTBI were included. By applying our reference values for GFAP and UCH-L1 across four age groups the biomarker combination (both biomarkers above reference ranges) had a sensitivity of 100% (95% CI 69-100), a negative predictive value of 100% (99-100), a specificity of 67% (63-71), a positive likelihood ratio of 3·01 (2·67-3·40), a negative likelihood ratio of 0, and an area under the curve of 0·83 (0·81-0·85) in identifying ciTBI. Serum GFAP and UCH-L1 identify ciTBI in children with 100% sensitivity and 67% specificity, which could potentially reduce unnecessary CCT scans and hospitalisations in children with mTBI if implemented. French Ministry of Health.

Diagnostic accuracy of ultrasound classifications – O-RADS US v2022, O-RADS US v2020, and IOTA SR – in distinguishing benign and malignant adnexal masses: Enhanced by combining O-RADS US v2022 with tumor marker HE4

PurposeTo assess the diagnostic accuracy of O-RADS Ultrasound (O-RADS US) v2022, O-RADS US v2020, and IOTA SR, and to evaluate whether combining imaging findings with tumor markers enhances the diagnosis of adnexal masses. MethodsThis retrospective study, conducted between January 2018 and December 2023, included consecutive women with adnexal masses scheduled for surgery. Histopathologic results served as the reference standard. Risk factors for malignancy were identified using univariate and multivariate logistic regression analyses. ROC analysis was employed to assess diagnostic test performances, while Kappa statistics evaluated inter-reviewer agreement. ResultsA total of 613 women (mean age, 49.39 ± 12.81 years; range, 16–87 years) with pelvic masses were included. O-RADS US v2022 exhibited comparable performance to O-RADS US v2020, with areas under the curve (AUC) values of 0.940 and 0.937, respectively (p = 0.02, exceeding the adjusted significance level of 0.0167). Both O-RADS models outperformed the IOTA SR, which had an AUC of 0.862 (p < 0.0001 for both comparisons). Multivariate analysis revealed that O-RADS US v2022 [OR 9.148, 95 %CI (4.912–17.039), p < 0.001] and HE4 [OR 1.023, 95 %CI (1.010–1.036), p = 0.001] were significant factors associated with malignant lesions. Furthermore, the combination of O-RADS US v2022 and HE4 demonstrated an AUC of 0.98, significantly outperforming either O-RADS US v2022 alone (AUC = 0.94) or HE4 alone (AUC = 0.92). The Kappa values for O-RADS US v2022, O-RADS US v2020 and IOTA SR were 0.933, 0.891 and 0.923, respectively, indicating substantial inter-reader agreement. ConclusionsThe O-RADS US v2022 demonstrates comparable performance in predicting ovarian malignant lesions when compared to O-RADS US v2020, while surpassing the performance of IOTA SR. Additionally, the combination of O-RADS US v2022 and HE4 provides improved diagnostic effectiveness over using either O-RADS US v2022 or HE4 alone.

Efficient modelling of infectious diseases in wildlife: A case study of bovine tuberculosis in wild badgers.

Bovine tuberculosis (bTB) has significant socio-economic and welfare impacts on the cattle industry in parts of the world. In the United Kingdom and Ireland, disease control is complicated by the presence of infection in wildlife, principally the European badger. Control strategies tend to be applied to whole populations, but better identification of key sources of transmission, whether individuals or groups, could help inform more efficient approaches. Mechanistic transmission models can be used to better understand key epidemiological drivers of disease spread and identify high-risk individuals and groups if they can be adequately fitted to observed data. However, this is a significant challenge, especially within wildlife populations, because monitoring relies on imperfect diagnostic test information, and even under systematic surveillance efforts (such as capture-mark-recapture sampling) epidemiological events are only partially observed. To this end we develop a stochastic compartmental model of bTB transmission, and fit this to individual-level data from a unique > 40-year longitudinal study of 2,391 badgers using a recently developed individual forward filtering backward sampling algorithm. Modelling challenges are further compounded by spatio-temporal meta-population structures and age-dependent mortality. We develop a novel estimator for the individual effective reproduction number that provides quantitative evidence for the presence of superspreader badgers, despite the population-level effective reproduction number being less than one. We also infer measures of the hidden burden of infection in the host population through time; the relative likelihoods of competing routes of transmission; effective and realised infectious periods; and longitudinal measures of diagnostic test performance. This modelling framework provides an efficient and generalisable way to fit state-space models to individual-level data in wildlife populations, which allows identification of high-risk individuals and exploration of important epidemiological questions about bTB and other wildlife diseases.

False-Positive Malaria Rapid Diagnostic Test Likely Due to African Tick Bite Fever: A Case Report

Background and Clinical Significance: Fever in the returning traveler is a medical emergency warranting prompt exclusion of potentially life-threatening infections such as malaria. Case Presentation: We describe a case of a febrile returned traveler to South Africa whose prompt initial diagnostic work-up was notable for a false-positive malaria rapid diagnostic test (RDT), and who nevertheless responded quickly to oral atovaquone-proguanil, despite an ultimate diagnosis of African tick bite fever. Subsequent RDT and malaria thick- and thin-film blood examination failed to corroborate a diagnosis of malaria and all other microbiological testing other than rickettsial serology remained non-contributory. Conclusions: The case presented highlights important points regarding diagnostic test performance characteristics and premature diagnostic closure.

Analytical Sensitivity Analysis and Clinical Impact Modeling of Rapigen Rapid Diagnostic Tests for Malaria.

Laboratory benchmarking allows objective analysis of the analytical performance of malaria rapid diagnostic tests (RDTs). We present the analytical detection limits of the Rapigen BIOCREDIT Malaria Ag Pf/Pv (pLDH/pLDH), the Rapigen BIOCREDIT Malaria Ag Pf (pLDH/HRPII), and two best-in-class WHO-prequalified comparator RDTs, generated using standardized panels containing recombinant antigen, invitro cultured parasites, international standards, and clinical samples. Detection limit antigen concentrations of HRP2, PfLDH, and PvLDH were determined for the Rapigen and comparator RDTs. Detection of antigens in international units (IU)/mL was also evaluated. The Rapigen Ag Pf (pLDH/HRPII) detected 3.9 and 3.9 IU/mL for PfLDH and HRP2, respectively, and the Ag Pf/Pv (pLDH/pLDH) detected 3.9 and 5.0 IU/mL for PfLDH and PvLDH, respectively. The comparator HRP2/PfLDH and HRP2/PvLDH detected 15.6 and 31.3 IU/mL for HRP2 and PfLDH and 15.6 and 50.0 IU/mL for HRP2 and PvLDH, respectively. The RDT clinical sensitivity was predicted through application of analytical detection limits to antigen concentration distributions from clinical symptomatic and asymptomatic cases. Febrile cases would be detected in a majority by both standard and Rapigen RDTs, but incremental increases in sensitivity in the Rapigen RDTs may be important for clinical cases currently missed by microscopy. Rapigen RDTs were predicted to have improved detection of asymptomatic cases and infections with parasites carrying hrp2 deletions through more sensitive PfLDH detection. Through the benchmarking and simulation of clinical sensitivity, a method for rapidly assessing the ability of new RDTs to meet clinical needs using high-sensitivity antigen distribution data is presented.

Accuracy of Xpert and alternative sampling methods to diagnose childhood pulmonary tuberculosis, a prospective cohort study

ObjectivesThe aim of the study was to estimate sensitivity and specificity of childhood pulmonary tuberculosis (CPTB) diagnostic tests, including Xpert and alternative samples such as nasopharyngeal aspirate and stool. We used latent class analysis to overcome the lack of gold standard. MethodsWe included 1165 children suspected of having CPTB in a prospective cohort study conducted in Ivory Coast, Madagascar, and Cameroon. We used Bayesian latent class analysis to evaluate the performance of multiple diagnostic tests for CPTB: smear microscopy, mycobacterial culture, and Xpert MTB/RIF carried out on different types of samples (sputum after 10 years of age, gastric aspirate before 10 of age, nasopharyngeal aspirate, stool), tuberculin skin test (TST), and chest X-ray. ResultsMedian age was 3.5 years (95% credible interval [1.3–8.2]). Smear microscopy was highly specific in all types of samples but lacked sensitivity (sputum 31% (95% credible interval [18–46]), gastric aspirate 36% [27–45], nasopharyngeal aspirate 24% [17–32], stool 24% [17–32]). Culture sensitivity was slightly higher in gastric (75% [65–83]) than nasopharyngeal aspirate (64% [54–72]). Xpert sensitivity was similar in gastric (69% [59–78]) and nasopharyngeal aspirate (66% [57–74]) but lower in sputum (58% [43–74]) and stools (53% [44–62]). Xpert was highly specific in all respiratory samples (sputum 96% [96–100], gastric aspirate 100% [99–100], nasopharyngeal aspirate 100% [99–100]). ConclusionsXpert performed on nasopharyngeal aspirate shows similar accuracy than culture. It was also similar to that in gastric aspirate. It highlights it’s an interesting CPTB diagnostic combination.

Prevalence of asymptomatic parasitaemia among household members of children under seasonal malaria chemoprevention coverage and comparison of the performance of standard rapid diagnostic tests versus ultrasensitive RDT for the detection of asymptomatic parasitaemia in Nanoro, Burkina Faso

Asymptomatic carriers of Plasmodium falciparum represent important parasite reservoirs maintaining malaria transmission in the community. This study aimed on the one hand to screen the other household members living with children under seasonal malaria chemoprevention (SMC) coverage in order to determine the level of malaria infection in this population and on the other hand to determine the appropriate type of rapid diagnostic test (RDT) for this screening to detect these asymptomatic carriers in the community. During the 2022 SMC campaign (July to October), a cross-sectional survey was carried out in 745 participants who were screened by ultrasensitive rapid diagnostic test (usRDT), standard rapid diagnostic test (rRDT) and microscopy. Out of them, 395 had microscopy results available and were included in the data analysis. The prevalence of asymptomatic carriers of asexual forms of Plasmodium falciparum was 26.58% (105/395) while sexual forms were found in 5.32% (21/395) of the study population. Children from 5 to 15 years had the highest prevalence of P. falciparum asexual forms 35.76% (59/165) compared with older participants. Malaria positivity rate for rRDT and usRDT was 29.40% (219/745) and 40.49% (305/745) respectively. The usRDT had a higher sensitivity than the rRDT (72.38% (95% CI 62.8–80.66) vs. 60.95% (95% CI 50.94–70.33)). In terms of specificity, rRDT had a higher specificity 82.41% (95% CI 77.53–86.62) versus 69.66% (95% CI 64.01–74.89) for usRDT. This study reports a high prevalence of parasite carriers in household members of children under SMC coverage in Nanoro, Burkina Faso. In conclusion, usRDT seems more appropriate for strategies based on detection and treatment of parasite carriers within the community.

Biomarker Assessment in Parkinson's Disease Dementia and Dementia with Lewy Bodies by the Immunomagnetic Reduction Assay and Clinical Measures.

Plasma biomarker assays provide an opportunity to reassess whether Alzheimer's disease, Parkinson's disease dementia (PDD), and dementia with Lewy bodies (DLB) plasma biomarkers are diagnostically useful. We hypothesized that immunomagnetic reduction (IMR) of plasma biomarkers could differentiate between patients with PDD and DLB and healthy patients when combined with established clinical testing measures. Plasma samples from 61 participants (12 PDD, 12 DLB, 37 controls) were analyzed using IMR to quantify amyloid-β 42 (Aβ42), total tau (t-tau), phosphorylated tau at threonine 181 (p-tau181), and α-synuclein (α-syn). Receiver operating characteristic curve (ROC) analysis was used to obtain sensitivity, specificity, and area under the ROC curve. Biomarker results were combined with clinical measures from the Unified Parkinson's Disease Rating Scale (UPDRS), Montreal Cognitive Assessment, and Hoehn-Yahr stage to optimize diagnostic test performance. Participants with PDD had higher α-syn than those with DLB and healthy participants and were distinguishable by their biomarker products Aβ42×p-tau181 and Aβ42×α-syn. Patients with DLB had higher p-tau181 than those with PDD and healthy participants and were distinguishable by their concentrations of α-syn×p-tau181. Plasma α-syn plus UPDRS versus either test alone increased sensitivity, specificity, and AUC when healthy patients were compared with those with PDD and DLB. Combined clinical examination scores and plasma biomarker products demonstrated utility in differentiating PDD from DLB when p-tau181 was combined with UPDRS, α-syn was combined with UPDRS, and α-syn×p-tau181 was combined with UPDRS. In this pilot study, IMR plasma p-tau181 and α-syn may discriminate between PDD and DLB when used in conjunction with clinical testing.

Cost-Effectiveness of an Ultrasound-First Strategy in the Diagnostic Evaluation of Noncalcified Lesions Recalled From Screening Digital Breast Tomosynthesis.

BACKGROUND. Ultrasound may be sufficient in the diagnostic evaluation of many noncalcified lesions recalled from screening digital breast tomosynthesis (DBT). In some scenarios, omission of diagnostic mammography can save health care costs. OBJECTIVE. The purpose of this study was to evaluate the cost-effectiveness of a strategy of performing ultrasound first versus diagnostic mammography first in the diagnostic evaluation of noncalcified lesions recalled from screening DBT. METHODS. Decision tree analysis was performed to compare ultrasound first versus diagnostic mammography first in the diagnostic evaluation of DBT-recalled noncalcified lesions from a U.S. health care system perspective with a 40-year horizon. The analysis used probabilities and prevalence information from published single-institution prospective data, additional literature-derived estimates of diagnostic test performance, and Medicare-allowable reimbursement rates. Health states were represented in a Markov chain model. For each strategy, the total cost and effectiveness (expressed in quality-adjusted life-years [QALYs]) were estimated. Cost-effectiveness was assessed through incremental cost-effectiveness ratios (ICERs) and incremental net monetary benefit, with use of a willingness-to-pay (WTP) threshold of US$100,000 per QALY gained. Deterministic sensitivity analyses were performed to estimate the impact of different input parameters, and probabilistic sensitivity analysis with Monte Carlo simulations was conducted to estimate the impact of combined uncertainty across parameters. RESULTS. In the base-case scenario, for diagnostic evaluation of DBT-recalled noncalcified lesions, a strategy of performing ultrasound first versus diagnostic mammography first resulted in more cost savings (total cost, US$17,672 vs US$18,323) and greater cost-effectiveness (QALYs, 23.1309 vs 23.1306) over the 40-year horizon. The ultrasound-first strategy resulted in an ICER of -2,170,000 (expressed as U.S. dollars per QALY) and an incremental net monetary benefit of US$681 versus the diagnostic mammography-first strategy. Therefore, performing ultrasound first was deemed the more cost-effective strategy at the WTP threshold. In deterministic sensitivity analyses, the most important driver of cost-effectiveness was lost utility from delayed diagnosis, followed by the relative sensitivities of ultrasound and diagnostic mammography. In probabilistic sensitivity analysis, ultrasound first was the better strategy in 93.0% of iterations. CONCLUSION. A strategy of performing ultrasound first, with or without diagnostic mammography, is more cost-effective than a traditional strategy of conducting diagnostic mammography first. CLINICAL IMPACT. This cost-effectiveness analysis supports the growing prioritization of ultrasound as the primary method for evaluating DBT-recalled noncalcified lesions.

6689 A Multicentric Study for Validation of the Diagnostic Accuracy of ACR-TIRADS in a Mexican population

Abstract Disclosure: M. Romero Ibarguengoitia: None. I.A. Villarreal-Ondarza: None. J. Mercado Basurto: None. A. González Cantu: None. The diagnostic performance of ultrasonographic ACR-TIRADS classification to evaluate thyroid nodules is poorly studied in a Mexican population. The aim was to assess the diagnostic accuracy of ACR-TIRADS classification for identifying malignant thyroid nodules in adults aged &amp;gt;18 years. This retrospective research study was conducted in 4 medical centers in Northern Mexico from 2022 to 23 to obtain ACR-TIRADS classification of nodules from thyroid ultrasound. Information about Bethesda classification after fine needle aspiration and cytology from thyroidectomy was analyzed for diagnostic performance tests. A total of 160 patients were included. Thyroid nodules were classified as TIRADS 3 in 12%, TIRADS 4 in 44%, and TIRADS 5 in 41%. Twenty-six (16%) were classified as Bethesda 1, 39 (24%) were classified as Bethesda 5, and 30 (19%) were classified as Bethesda 6. The sensitivity (S) of TIRADS 4 was 41%, specificity (E) was 50%, positive predictive value (PPV) was 59%, negative predictive value (NPV) was 32%, and accuracy was 44%. The S of TIRADS 5 was 51%, E 77%, PPV 80%, NPV 47%, and accuracy of 61%. When comparing with other populations, the performance was the same as the Turkish (their accuracy was 59.93%) population but lower than a population from China (their accuracy was 86%) and Germany (PPV 100% for TIRADS 5). The proportion of malignancy in our sample compared with a reference sample from Germany was lower, 36 vs. 85% for TIRADS 3, 59 vs. 85% for TIRADS 4, and 80% vs. 100%, p&amp;lt; 0.001. Concerning Bethesda's classification, the proportion of malignancy was the same according to the reference sample from the American Thyroid Association. In conclusion, there was a moderate accuracy of the ACR-TIRADS classification system in our population, the same in comparison with the Turkish population; slightly lower than what is reported in a population from Germany and China. Presentation: 6/1/2024

Golden-angle radial sparse parallel (GRASP) magnetic resonance angiography (MRA) for endoleak evaluation after endovascular repair of the aorta: a prospective comparison to conventional time-resolved MRA.

Time-resolved angiography with interleaved stochastic trajectories (TWIST) magnetic resonance angiography (MRA) may obscure smaller vessels and is highly susceptibility to motion artifacts, potentially reducing endoleak detection accuracy after endovascular aortic repair (EVAR). The novel golden-angle radial sparse parallel (GRASP) sequence enhances spatial and temporal resolution with continuous, motion-robust datasets, showing promise for accurate endoleak detection post-EVAR. This study aimed to compare the diagnostic effectiveness of contrast-enhanced compressed-sensing radial GRASP-volume interpolated breath-hold examination (VIBE) sequence with standard contrast-enhanced dynamic TWIST-VIBE sequence in patients with inconclusive computed tomography angiography (CTA) findings regarding endoleak after EVAR. This single-center prospective study consecutively enrolled adults with inconclusive findings regarding the presence or type of endoleak in multiphasic CTA following EVAR for abdominal aortic aneurysms. Participants underwent contrast-enhanced MRA, acquiring dynamic TWIST-VIBE and GRASP-VIBE sequences. Two independent radiologists assessed the datasets for image quality, diagnostic confidence, and the presence and type of endoleak. Additionally, quantitative assessments with signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were performed. Statistical analyses included interrater and intermethod agreement, and diagnostic performance testing. Twenty participants (mean age, 72±9 years; 13 males) were included. GRASP-VIBE demonstrated superior image quality over TWIST-VIBE sequence with predominantly absent motion artifacts and increased diagnostic confidence (all P<0.001). Diagnostic performance significantly improved for detecting type II endoleaks in GRASP-VIBE compared to TWIST-VIBE scans [area under the curve (AUC): 0.96 vs. 0.73; P=0.04]. Diagnostic accuracy improved with GRASP-VIBE for overall (AUC: 0.94 vs. 0.79) and endoleak type I detection (AUC: 1.0 vs. 0.90), however, not significantly (P≥0.05). TWIST-VIBE sequences demonstrated significantly higher SNR for measurements in the clotted aneurysm sac (P=0.01). No significant differences were observed in CNR for the aorta and any aneurysm sacs across the compared imaging sequences. Compressed-sensing dynamic GRASP-VIBE sequence, with its superior image quality, diagnostic confidence, and performance, may be preferred over standard TWIST-VIBE sequence in inconclusive endoleak cases.

Diagnostic Accuracy of Multitarget Stool DNA Test for Colorectal Cancer Screening and Detecting in Thailand.

A multitarget stool DNA test offers high sensitivity and specificity for screening and detecting colorectal cancer (CRC) in Western populations. However, its accuracy in Asian people is not well known. This study aimed to examine the diagnostic performance of multitarget stool DNA tests in Thailand. A prospective cross-sectional study was conducted from January 2023 to November 2023 at a tertiary university hospital in Bangkok. The study included both asymptomatic and symptomatic patients who underwent stool DNA testing followed by colonoscopy. The multitarget stool DNA test targeted methylation statuses of SDC2, ADHFE1, and PPP2R5C genes. Sensitivity, specificity, and other diagnostic parameters were analyzed. A total of 274 patients (mean age 62.1 years, 60.6% female) were enrolled. CRC was diagnosed in 17.2% of participants and 6.2% had advanced adenomas. The multitarget stool DNA test demonstrated a sensitivity of 91.5% (95% CI: 79.6-97.6) and specificity of 90.3% (95% CI: 85.7-93.8) for CRC detection. Its sensitivity for detecting CRC did not differ between right-sided lesions (92.3%) and left-sided lesions (91.2%) (P=0.901). The sensitivity for detecting CRC lesions size less than 2 cm was significantly lower than for larger lesions (25% vs 91.7%, p<0.001). Notably, the test's sensitivity and specificity for advanced colorectal neoplasms/cancer were 75.0% (95% CI: 62.6-85.0) and 91.9% (95% CI: 87.4-95.2), respectively. Multitarget stool DNA testing is highly sensitive and specific for CRC detection in Thai individuals. This testing could represent as a viable non-invasive alternative to colonoscopy especially in settings where colonoscopy is less accessible or less accepted by patients.

Performance of post-mortem diagnostic tests for tuberculosis in wild ungulates at low and high prevalence assessed using Bayesian latent class models.

Animal tuberculosis (TB) is often maintained by multi-host communities, including livestock and wildlife. Quantitative studies of such communities require estimating the true prevalence of TB, correcting the apparent prevalence by the diagnostic sensitivity (Se) and specificity (Sp) of the test. The goal of this study was to lay the foundations for estimating the true prevalence of TB in wild ungulate populations (wild boar and two cervids: red deer and fallow deer). We used Bayesian latent class models to assess the Se and Sp of gross pathology, IS6110 real-time PCR in tissues, bacteriological culture, and P22 indirect ELISA. We analyzed 308 harvested wild ungulates (211 wild boar and 97 cervids: 92 red deer and 5 fallow deer). The Se of bacteriological culture (80.4%, CI95 61.0-96.3%) and gross pathology (87.9%, CI95 69.5-99.9%) was reasonably good in wild boar. These tests showed lower Se in cervids: 60.2% (CI95 38.3-82.3%) for bacteriological culture and 81.5% (CI95 63.6-96.2%) for gross pathology. The Se of the real-time PCR was low (50.7% in wild boar and 53.0% in cervids). These tests showed Sp between 95.2 and 99.1% in both taxa. The P22 ELISA performed reasonably well in wild boar (Se = 71.9%, CI95 59.2-83.4%; Sp = 98.8%, CI95 96.9-99.9%) but lacked Sp in cervids (Se = 77.1%, CI95 62.9-89.7%; Sp = 74.5%, CI95 65.7-83.3%). The real-time PCR in wild boar and cervids and bacteriological culture in cervids tended to show higher Se in low-prevalence populations, possibly due to a higher proportion of early-stage TB lesions. In cervids, the parallel interpretation of gross pathology and bacteriological culture significantly improved the diagnostic performance (Se = 93.1%, CI95 84.7-98.9%; Sp = 92.9%, CI95 86.0-98.3%). Our results allow the estimation of true prevalence from the results of a single diagnostic test applied to harvested wild boar, red deer, and fallow deer, paving the way for more precise quantitative ecological studies of the multi-host TB maintenance community.

Evaluation of three serological tests for the diagnosis of Brucella suis in dogs using Bayesian latent class analysis

Brucella suis infection of dogs is an emerging issue worldwide requiring specific management to address zoonotic risks and animal welfare concerns. Diagnosis in dogs is routinely based on serological testing, but to date these tests have only been validated for use in production animal species and humans. This study aimed to assess the diagnostic performance of three commonly used serological tests in dogs. Canine sera (n = 989) were tested with the Rose Bengal rapid plate agglutination test (RBRPT), the complement fixation test (CFT) and a competitive ELISA (C-ELISA). Diagnostic test performance was evaluated using a three test, two population Bayesian latent class analysis accounting for conditional dependence between the three tests. Positive and negative predictive values (PPV, NPV) were calculated for a range of expected prevalence estimates for the individual tests and test combinations interpreted in series and parallel. The RBRPT showed the highest individual Se of 0.902 (95 % posterior credible interval [PCI] 0.759–0.978) and the CFT the highest individual diagnostic specificity (Sp) of 0.914 (95 % PCI 0.886–0.946). The C-ELISA had marginally the best overall diagnostic performance (Youden’s index = 0.807). The CFT and the C-ELISA interpreted in parallel returned the highest combined Se and Sp (0.988 and 0.885, respectively). All tests returned NPVs of > 0.982 in 2–8 % prevalence settings. Series interpretation of the three-test combination as well as the two-test combinations of the RBRPT and the C-ELISA and the CFT and the C-ELISA produced a PPV of 0.502 when the estimated prevalence was 8 %. While all tests are suitable for the detection of B. suis antibodies in dogs, they should not be interpreted in isolation as their diagnostic value is dependent on the pre-test probability of the disease. As such they are useful tools for the diagnosis of B. suis in dogs when exposure, history and clinical presentation indicate a risk of brucellosis.

Evaluating the ability of non-tuberculous mycobacteria to induce non-specific reactions in bovine tuberculosis diagnostic tests in guinea pigs and cattle

Limitations in diagnostic test performance are one of the major challenges hampering the eradication of bovine tuberculosis (bTB). Non-tuberculous mycobacteria (NTM) are considered one of the main causes of non-specific reactions in the intradermal tuberculin test, the most widely used bTB diagnostic test. To determine the role of NTMs in bTB misdiagnosis in Spain, an experimental study including the NTM species most commonly found in bTB-positive animals from bTB-free farms in the country (M. avium subsp. avium (Maa), “Mycobacterium avium subsp. hominissuis” (Mah), M. bourgelatii, M. intermedium, M. kansasii and M. nonchromogenicum) was carried out on guinea pigs and cattle. First, guinea pigs were sensitized with the selected NTMs, and six weeks post-sensitization four antigen mixtures (bovine-PPD, avian-PPD, P22 and ESAT6-CFP10) were inoculated intradermally and their effect was measured 24- and 48-h post-inoculation. Larger erythematous reactions were observed in guinea pigs sensitized with Mah, M. kansasii, and Maa, with significant differences in the reactions measured at the bovine-PPD inoculation site for the two first bacteria compared with other NTMs. The sensitization process was repeated in cattle, and five months post-sensitization the same antigen mixtures were inoculated in the cervical region and responses were measured at 48- and 72-h post-inoculation. A significantly higher increase in the skinfold thickness measured at the bovine-PPD inoculation site was observed in calves sensitized with Mah, Maa, M. intermedium and M. kansasii. These results demonstrate that certain NTM species may play a more significant role in bTB diagnostic interferences and show that results obtained in guinea pig and bovine models do not always coincide.

Diagnostic Performance of Preoperative Calcitonin and Procalcitonin Tests for Differential Diagnosis of Medullary Thyroid Cancer.

Medullary thyroid cancer (MTC) shows a relatively poor prognosis among thyroid cancers. Though calcitonin has been used as a diagnostic marker for MTC, it has disadvantages including poor sample stability and discrepancies among results by assay. This study aimed to compare the usefulness of preoperative calcitonin and procalcitonin (PCT) in the diagnosis of MTC. Serum calcitonin and PCT levels were measured before thyroidectomy from MTC (n = 23) and other types of thyroid cancers in patients (n = 1308). Diagnostic performances of calcitonin and PCT for discerning MTC were estimated. In a multivariate analysis, preoperative calcitonin level was independently associated with the diagnosis of MTC, whereas PCT was not. Calcitonin and PCT, respectively, exhibited area under the curve values of 0.997 and 0.979 for the diagnosis of MTC, without significant differences. For calcitonin, the sensitivity, specificity, and positive and negative predictive values were 0.957, 0.992, 0.688, and 0.999, respectively, at a cut-off of 7.2 pg/mL. The corresponding values for PCT were 0.913, 0.995, 0.778, and 0.998 at a cut-off of 0.19 ng/mL. Preoperative calcitonin and PCT showed similar diagnostic utility for MTC. Depending on the patient's clinical status and laboratory environment, these tests can be used as complementary methods for detecting MTC.