High Pretest Probability Research Articles

Lung Point in a Case of Bronchoscopy Lung Volume Reduction: Consider Its Mimics Before Inserting the Tube

Point of Care Ultrasound (POCUS) is used to evaluate many clinical scenarios. Chest POCUS has been integrated as a part of a clinical protocol to assess patients with lung pathology [1]. The ability to detect pneumothorax using chest POCUS has been shown to be superior to chest radiography, with specificity reported to be as high as 100% when a lung point sign is identified. In addition to improved diagnostic accuracy, chest POCUS has the added benefits of ease of access and absence of ionizing radiation. Here we describe a case where a patient with a high pre-test probability for pneumothorax had a detected lung point sign, but pneumothorax was ruled out via Computed Tomography (CT). This case highlights the importance of considering the mimics of the lung point sign. This case also shows a unique and interesting finding related to pleural movement restriction post-Bronchoscopic lung volume reduction (BLVR).

Prospective Validation and Usability Evaluation of a Mobile Diagnostic App for Obstructive Sleep Apnea

Background/Objectives: Obstructive sleep apnea (OSA) classification relies on polysomnography (PSG) results. Current guidelines recommend the development of clinical prediction algorithms in screening prior to PSG. A recent intuitive and user-friendly tool (OSABayes), based on a Bayesian network model using six clinical variables, has been proposed to quantify the probability of OSA. Our aims are (1) to validate OSABayes prospectively, (2) to build a smartphone app based on the proposed model, and (3) to evaluate app usability. Methods: We prospectively included adult patients suspected of OSA, without suspicion of other sleep disorders, who underwent level I or III diagnostic PSG. Apnea–hypopnea index (AHI) and OSABayes probabilities were obtained and compared using the area under the ROC curve (AUC [95%CI]) for OSA diagnosis (AHI ≥ 5/h) and higher severity levels (AHI ≥ 15/h) prediction. We built the OSABayes app on ‘App Inventor 2’, and the usability was assessed with a cognitive walkthrough method and a general evaluation. Results: 216 subjects were included in the validation cohort, performing PSG levels I (34%) and III (66%). OSABayes presented an AUC of 83.6% [77.3–90.0%] for OSA diagnosis and 76.3% [69.9–82.7%] for moderate/severe OSA prediction, showing good response for both types of PSG. The OSABayes smartphone application allows one to calculate the probability of having OSA and consult information about OSA and the tool. In the usability evaluation, 96% of the proposed tasks were carried out. Conclusions: These results show the good discrimination power of OSABayes and validate its applicability in identifying patients with a high pre-test probability of OSA. The tool is available as an online form and as a smartphone app, allowing a quick and accessible calculation of OSA probability.

Diagnostic Performance of a Newly-Launched Canadian Fast-Track Ultrasound Clinic by Rheumatologists for the Diagnosis of Giant Cell Arteritis.

Giant Cell Arteritis (GCA) can present diagnostic challenges and early diagnosis is crucial due to potential ischemic complications. Recent guidelines suggest that a suspected diagnosis should be confirmed with temporal artery biopsy or imaging, including ultrasound (US). In our Canadian setting, point-of-care temporal artery US was near unavailable, and biopsy remains the standard of care. We hypothesize that launching a fast-track US clinic by rheumatologists may spare the need for a temporal artery biopsy. Therefore, this study aimed to assess the diagnostic performance of US in this newly-launched fast-track clinic. In this single-center retrospective cross-sectional analysis, 99 visits were identified from the fast-track clinic between January 2020 and July 2022. Each subject had an US according to a standard protocol for suspicion of either new-onset or relapse of GCA. Ultrasonographers were rheumatologists who acquired training on vascular US techniques before launching the clinic. For each patient presenting with suspected new-onset GCA, the pre-test probability was calculated using the Southend GCA probability score. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using the rheumatologist clinical diagnosis as the gold standard for GCA diagnosis. A total of 22 subjects had a diagnostic of GCA and 77 had another diagnostic. Patients with and without GCA were, respectively, 81.8% vs 72.7% females, had a mean age of 76.6 ± 7.7 vs. 74.8 ± 9.8 years and a mean CRP of 73.4 ± 57.8 vs 38.3 ± 59.9 mg/L. Temporal artery US demonstrated a a sensitivity of 86.3% [95% confidence interval (CI), 65.1%-97.1%], a specificity of 90.9% (95% CI, 82.2%-96.3%), a PPV of 73.1% (95% CI, 56.8%-84.9%) and a NPV of 95.9% (95% CI, 89.0%-98.5%). 14 patients had a suspicion of relapse and were all correctly identified by the US. Among those with suspicion of new-onset 27, 34 and 24 US were performed for high, intermediate, and low pretest probability of GCA, respectively. The high-risk subgroup demonstrated higher PPV while similar sensitivity/specificity were observed between all three subgroups. Our results highlights the benefits of US as a key diagnostic tool for GCA, particularly when combined with clinical evaluations. An excellent discriminative ability for diagnosis of GCA was shown in this newly-launched clinic suggesting that the role of TAB may need to be redefined. These findings will guide on broader implementation of US programs for GCA.

Update Motility Disorders: Gastro-Oesophageal Reflux Disease – Diagnostic and Conservative Approach

Background: Gastro-oesophageal reflux disease (GORD) is extremely common, with at least 1 in 10 people in the general population reporting heartburn and acid regurgitation on a weekly basis. GORD can also be associated with a variety of atypical symptoms, including chest pain, chronic cough, and laryngopharyngeal symptoms. The causes of GORD are multifactorial, and the severity of symptoms is influenced by peripheral and central factors, including psychosocial stress and anxiety. Therefore, for a variety of reasons, no single investigation provides a definitive diagnosis, and standard treatment with acid suppressants is not always effective. Summary: This review introduces the Lyon Consensus, now in its second iteration, a classification system that provides a “conclusive” positive or negative diagnosis of GORD by integrating the results of endoscopy, ambulatory reflux monitoring, and high-resolution manometry. Different algorithms are applied to patients with high and low pre-test probability of a causal relationship between reflux episodes and patient symptoms. The results of these studies identify patients with “actionable” results that require escalation, revision, or discontinuation of GORD treatment. Guidance is provided on the range of conservative treatments available for GORD, including dietary and lifestyle advice, antacids and alginates, and drugs that suppress acid secretion. Key Messages: GORD is a common disorder; however, the causes of reflux and symptoms can be complex. As a result, the diagnosis can be missed, and management is sometimes challenging, especially for patients with atypical symptoms. The Lyon classification establishes a conclusive diagnosis of GORD, based on results of endoscopic and physiological investigation. Typical symptoms usually respond to empiric use of alginate-antacid preparations and acid suppression; however, the management of treatment refractory symptoms is tailored to the individual.

Prenatal detection of placenta accreta spectrum using a sonographic checklist.

The European Working Group for Abnormally Invasive Placenta proposed a checklist of ultrasound features for the antenatal detection of placenta accreta spectrum (PAS). This study aims to assess the performance of the checklist in identifying histopathologically confirmed PAS cases in a cohort with a high pre-test probability of PAS, and identify if particular features are associated with PAS. This is a prospective multi-site cohort study conducted between 2018 and 2023. Consecutive patients who underwent ultrasound assessment for suspicion of PAS were included, and the sonographic checklist was completed at the time of ultrasound. Cases were defined as PAS where they had intraoperative findings as described by the International Federation of Gynecology and Obstetrics (FIGO) grading, and histopathological findings for hysterectomy and myometrial resection cases. All non-PAS cases in this study had placenta previa and at least one prior cesarean delivery. Seventy-eight participants met inclusion criteria, of whom 63 (80.7%) were diagnosed with PAS. Cesarean hysterectomy was performed in 49 cases (62.8%). Overall, third-trimester ultrasound performed at a median gestational age of 32 weeks (IQR 30-34 weeks) had a sensitivity of 0.84 (95% CI 0.73 to 0.92) and specificity of 0.73 (95% CI 0.45 to 0.92) for detecting PAS, with a positive and negative likelihood ratio of 3.15 (95% CI 1.35 to 7.35) and 0.22 (95% CI 0.11 to 0.41), respectively. Features most associated with PAS were abnormal placental lacunae (Odds Ratio [OR] 5.40 [95% CI 1.61 to 18.03] and myometrial thinning OR 6.87 [95% CI 1.93 to 24.4]). While many of the ultrasound features seen in PAS were also present in cases of placenta previa with prior Cesarean section, the median (IQR) number of features present in PAS cases was significantly higher than in the non-PAS placenta previa group (six features [3-8] vs. two features [0-3] p = 0.001). No case of non-PAS placenta previa had more than five features present. The use of a standardized sonographic checklist had a high sensitivity and good specificity for the detection of PAS in this prospective cohort of well-classified PAS cases.

To PE or Not to PE: Perfusion SPECT/CT Avoids Overdiagnosis.

A 41-year-old woman with metastatic breast cancer presented with dyspnea, hypoxia, and elevated d -dimer. Perfusion planar imaging followed by SPECT/CT of the chest was performed due to the patient's iodinated contrast allergy. Planar images showed multiple pleural-based wedge-shaped defects concerning for bilateral pulmonary embolism (PE). Perfusion SPECT/CT of the chest confirmed multiple areas of perfusion defects but was considered negative for PE and attributed the perfusion defects to the compressing of pulmonary vasculature from metastatic lymph nodes and pulmonary masses. Given the high pretest probability of PE, a CT pulmonary angiogram was performed after premedication for contrast allergy confirming absence of PE.

Our Experiences and Learnings in Diagnosing MODY from Non-Institutional-Based Diabetes Care Clinics

Abstract Introduction: Maturity-onset diabetes of the young (MODY) is a rare group of disorders characterised by impaired functions or development of pancreatic islets and monogenic diabetes at a young age. Diagnosing MODY can be rewarding for both clinicians and patients as it can change the management from generic to targeted therapy. Methods: This study reports the retrospective analysis of data collected from four clinics between March 2016 and February 2023 from Lucknow, a city in northern India. Fifty-three individuals are suspected to be affected by MODY based on ISPAD guidelines. Following a detailed clinical evaluation, they were referred for genetic diagnostic testing. Results: The cohort consists of 19 females and 34 males with a mean age of diagnosis of 25.3 years and a body mass index of 22.3 Kg/m2. Genetic testing detected variants in 13/53 (~24.5%) individuals. Five cases had significant pathogenic/likely pathogenic variants, HNF1A gene in two [(p.Phe268LeufsTer74) (p.Arg200Gln)], one each in HNF4A (Arg311His), PDX1(p.Ala228GlyfsTer33), and a case with suggestive digenic variants in HNF1A gene (p.Arg200Gln) and HNF1B [(p.Leu13Met)]. Variants of uncertain significance (VUSs) with inconclusive evidence of pathogenicity were reported in eight patients, and five were considered to be clinically significant as they are lean young onset, sulfonylurea-responsive, and presented with diabetes without acanthosis nigricans and with high pretest probability. These individuals harboured variants in HNF1A (p.Thr425_Thr429delinsPro), HNF1B (p.Ser19Phe), CEL (p.Val681ArgfsTer6), ABCC8 (p.Ile872Met), and KCNJ11 (p.Arg221Cys) genes. Conclusion: We found a diagnostic yield of around 10% of pathogenic or likely pathogenic variants in individuals who were suspected to have MODY. As it is a field that is still evolving, we might consider starting with oral agents under close supervision in those individuals who have VUS; there are some proportions of individuals who might not have classical sulfonylurea-responsive genetic variants, but they might respond to it.

Accuracy of the Dual Path Platform (DPP) rapid test for the diagnosis of leptospirosis: A multi-center study in six Brazilian states

Leptospirosis is a zoonotic disease with significant global impact and a challenging diagnosis. The utilization of adequately validated rapid tests is relevant for the opportune identification of the disease and for reduction in fatality rates. The present study analyzes the accuracy and reliability of the Dual Path Platform (DPP) assay -produced in Brazil by the Oswaldo Cruz Foundation (Fiocruz)- for diagnosing leptospirosis. Firstly, a serological panel was constructed in the Brazilian Reference Laboratory for Leptospirosis using samples routinely handled by reference laboratories of six Brazilian states. It consisted of 150 positive (according to MAT and IgM-ELISA) and 250 negative samples for leptospirosis. Subsequently, the panel samples were distributed to the reference laboratories for the performance of DPP assays in triplicate. Different measures were used in the assessment of diagnostic quality. Predictive values were estimated for different pre-test probability settings. Sensitivities varied between 67.33 % and 74.00 % and specificities between 93.20 % and 98.40 % in the states, and there were adequate agreements between them. Accuracies were lower for the samples of patients with less than 7 days of symptoms. In contexts of prevalence values up to around 25 %, positive and negative predictive values were around 90 %. However, in situations of high pre-test probabilities, NPVs were low. This study improves understanding of the use of DPP in diagnosing leptospirosis, particularly its application in healthcare settings. As long as the time of symptoms onset and clinical and epidemiological contexts are adequately considered for the interpretation of results, DPP is a valid option to be used in the leptospirosis diagnostic routine.

Does the ESC chronic coronary syndrome pre-test probability score assist coronary artery disease diagnosis in an advanced nurse practitioner led integrated community chest pain clinic?

Abstract Background The Advanced Nurse Practitioner (ANP) led integrated community chest pain clinic provides an alternative avenue to which GPs can refer patients with non-acute chest pain providing emergency dept. avoidance. The role of the ANP is to differentiate between a non-anginal versus anginal cause. In addition to taking a clinical history, physical assessment and ECG the ANP utilises the 2019 ESC guidelines for chronic coronary syndromes pre-test-probability (PTP) score, to judge if invasive investigation is required. Purpose ANP assessment of chest pain in a community clinic is unique in the Irish healthcare setting. The aim was to assess if angina characteristics & allocated ESC PTP were predictive of coronary artery disease (CAD) diagnosis in a community chest pain cohort. Method A retrospective audit of 144 patients assessed by the ANP in the ICCPC and subsequently referred for coronary angiography was performed. Final diagnosis of was analysed by i. anginal characteristic, ii. ESC PTP, iii. age and sex. Approval was given by the department of quality, safety and risk management. Results The average combined age was 61 years in n=92 Male, and n=51 Female patients. Coronary Artery Disease was diagnosed in 92% (n= 132) of those referred for angiography; obstructive CAD in 38% (n=55) and non-obstructive CAD (NOCAD) in 54% (n=77). The ANP allocated the angina characteristic ‘typical’ in 31% (n=45) cases and 58% (n=26) were diagnosed with obstructive CAD, average PTP of 20%, and 38% (n=17) were diagnoses with NOCAD. In those with ‘typical’ symptoms only two cases resulted in normal coronary arteries. Conversely 34% (n=49) were allocated ‘non-anginal’ symptoms, in whom 28% (n=14) obstructive CAD was detected; 12 cases had an intermediate to high PTP due to age and clinical likelihood. The majority of referrals (57%) were ‘high’ PTP of CAD (≤16%-52%), average 22%. The average PTP was 27% (High) in those diagnosed with CAD versus a PTP of 11% (Intermediate) in those with normal coronaries (n=12). The new category of ‘dyspnoea’ was allocated to 14% (n=20) and resulted in diagnosis of NOCAD (n=12) and (n=5) CAD. Those with dyspnoea as a presenting symptom of CAD were all male with high PTP. Conclusion Pre-test-probability and age are highly correlated, rising with age and defined by sex. The main variable is the ‘angina’ characteristic allocated by the ANP. In this community-based cohort, ‘typical’ symptom allocation by the ANP resulted in a higher PTP and subsequent CAD diagnosis. Clinical suspicion in the ‘low-intermediate risk’ can be further adjusted using the clinical likelihood ratio. The value of the PTP score in predicting CAD is as useful as the ‘angina’ characteristic and clinical likelihood allocated, requiring expert health history taking. This retrospective analysis of coronary angiogram results in this community cohort evidences that the ANP is skilled in utilising the ESC PTP score to assist in the diagnosis of CAD.

Validation of the 2023 International Diagnostic Criteria for MOGAD in a Selected Cohort of Adults and Children.

To test the performance of the 2023 myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) criteria in adults and children with inflammatory demyelinating conditions who were tested for MOG antibodies (Abs). This was a retrospective study of patients tested for MOG-Abs from 2018 to 2022 in 2 specialist hospitals. The inclusion criteria comprised ≥1 attendance in an adult or pediatric demyelinating disease clinic and complete clinical and MRI records. The final clinical diagnosis of MOGAD, made by the treating neurologist, was taken as the benchmark against which the new criteria were tested. The international MOGAD diagnostic criteria were applied retrospectively; they stipulate at least 1 clinical or MRI supporting feature for MOGAD diagnosis in positive fixed MOG cell-based assay without a titer. The performance MOG-Ab testing alone for MOGAD diagnosis was also assessed and compared with that of MOGAD criteria using the McNemar test. Of the 1,879 patients tested for MOG-Abs, 539 (135 pediatric and 404 adults) met the inclusion criteria. A clinical diagnosis of MOGAD was made in 86/539 (16%) patients (37 adults, 49 children), with a median follow-up of 3.6 years. The MOGAD diagnostic criteria had sensitivity of 96.5% (adults 91.9%, children 100%), specificity of 98.9% (adults 98.8%, children 98.9%), positive predictive value of 94.3% (adults 89.4%, children 98%), negative predictive value of 99.3% (adults 99.2%, children 100%), and accuracy of 98.5% (adults 98.3%, children 99.2%). When compared with MOG-Ab testing alone, a difference was seen only in adults: a significantly higher specificity (98.9% vs 95.6%, p = 0.0005) and nonstatistically significant lower sensitivity (91.9% vs 100%, p = 0.08). The international MOGAD diagnostic criteria exhibit high performance in selected patients with inflammatory demyelinating diseases (who had a high pretest probability of having MOGAD) compared with best clinical judgment; their performance was better in children than in adults. In adults, the MOGAD criteria led to an improvement in specificity and positive predictive value when compared with MOG-Ab testing alone, suggesting that the requirement of at least 1 clinical or MRI supporting feature is important. Future work should address the generalizability of the diagnostic criteria to cohorts of greater clinical diversity seen within neurologic settings.

Mandibular movement monitor provides faster, yet accurate diagnosis for obstructive sleep apnoea: A randomised controlled study

Many patients with obstructive sleep apnoea (OSA) remain undiagnosed and thus untreated, and in part this relates to delay in diagnosis. Novel diagnostic strategies may improve access to diagnosis. In a multicentre, randomised study, we evaluated time to treatment decision in patients referred for suspected OSA, comparing a mandibular movement (MM) monitor to respiratory polygraphy, the most commonly used OSA detection method in the UK. Adults with high pre-test probability OSA were recruited from both northern Scotland and London. 40 participants (70 % male, mean±SD age 46.8 ± 12.9 years, BMI 36.9 ± 7.5 kg/m2, ESS 14.9 ± 4.1) wore a MM monitor and respiratory polygraphy simultaneously overnight and were randomised (1:1) to receive their treatment decision based on results from either device. Compared to respiratory polygraphy, MM monitor reduced time to treatment decision by 6 days (median(IQR): 13.5 (7.0–21.5) vs. 19.5 (13.7–35.5) days, P = 0.017) and saved an estimated 29 min of staff time per patient.

Accuracy of Glucagon Testing Across Transition in Young Adults with Childhood-Onset Growth Hormone Deficiency.

The 2019 AACE guidelines suggested peak GH-cutoffs to glucagon test (GST) of ≤3 µg/L and ≤1 µg/L in the diagnosis of permanent GH deficiency (GHD) during the transition phase. Aim of the study was to evaluate the accuracy of GST compared to insulin tolerance test (ITT) in the definition of GHD at adult height achievement. Ninety-seven subjects with childhood-onset GHD (median age, 17.39 years) underwent ITT, GST and IGF-1 testing; 44 subjects were idiopathic (isolated GHD), 35 moderate organic GHD (0-2 hormone deficiencies-HDs) and 18 severe organic GHD (≥3 HDs). Bland and Altman analysis showed a high consistency of GH peak measures after ITT and GST. Receiver operating characteristic analysis-ROC- identified 7.3 μg/L as the optimal GH peak cutoff to GST (95% CI 4.15-8.91; sensitivity 95.7%, specificity 88.2%, positive predictive value-PPV-88.0%, negative predictive value-NPV-95.7%), able to correctly classify 91.8% of the entire cohort while 5.8 μg/L was the best GH peak cutoff able to correctly classify 91.4% of moderate organic GHD patients (95% CI 3.16-7.39; sensitivity 96.0%, specificity 80.0%, PPV 92.3%, NPV 88.9%). Patients with ≥3HDs showed a GH peak <5μg/L at ITT and <5.8μg/L at GST but one. The optimal cutoff for IGF1 was -1.4 SDS (95% CI -1.94-0.77; sensitivity 75%, specificity 94%, PPV 91.7%, NPV 81.0%) that correctly classified 85.1% of the study population. A GH peak to GST <5.8 μg/L represents an accurate diagnostic cutoff for young adults with childhood-onset GHD and high pre-test probability of permanent GHD.

Neural Antibodies in First-episode Psychosis Patients with Warning Signs for Autoimmune Encephalitis.

: Autoimmune encephalitis (AE) remains an essential differential diagnosis in patients with first-episode psychosis (FEP). In this study, we aimed to assess to prevalence of AE in a cohort of FEP patients. : We used a phenotype-driven algorithm to detect AE in patients with FEP. Initially, we screened patients for warning signs with a low or high pre-test probability for AE, defined as "yellow" and "red flags", respectively. In the next step, patients with red flags underwent cerebrospinal fluid analysis (including neural antibodies), while patients with yellow flags underwent tests for serum neural antibodies, electroencephalography, and brain magnetic resonance imaging. : We screened 78 patients with FEP and found that eight (10.3%) had at least one warning sign for AE: four (5.13%) patients had at least one red flag, while four (5.13%) had only yellow flags. Among these, two patients (2.56%) had anti-N-methyl-D-aspartate receptor encephalitis, while the remaining six (7.69%) received a primary psychiatric disorder diagnosis. : Our study highlights the importance of considering AE in the differential diagnosis of FEP.

Testing and Diagnosis of Clostridioides difficile Infection in Special Scenarios: A Systematic Review.

Clostridioides difficile infection (CDI) is a clinical and laboratory diagnosis.Populations at higher risk of developing disease require a high clinical index of suspicion for laboratory testing to avoid incorrect assumptions of colonization. Common risk factors include recent antibiotic use, elderly (>65 years old), and immunocompromised patients.C. difficile assays shouldbe ordered in an algorithm approach to diagnose an infection rather than colonization. Screening tests are widely available in hospital systems, but novel molecular testing may aid in diagnosis in patients with inconclusive or discordant antigen and toxin test results. Methods: Data was extracted from PubMed, Scopus, and Cumulative Index of Nursing and Allied Health Literature (CINAHL) databases based on the keywords "clostridioides difficile", "toxin assay", and "toxic megacolon". The data extracted is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. A total of 27 reports were included in this systematic review. Testingpatients with a significant gastrointestinal surgical history, hypogammaglobulinemia, inflammatory bowel disease, intensive care unit, and immunocompromised patients for CDI is highly recommended. Diarrhea in these subsets of patients requires correlation of clinical context and an understanding of assay results to avoid over- and under-treating. CDI should be considered in all patients with traditional risk factors. Heightened clinical suspicion of CDI is required in patients with hypogammaglobulinemia, transplant recipients, patients with gastrointestinal surgical history, and inflammatory bowel disease. Testing should be limited to patients with clinical manifestations of CDI to ensure a high pretest probability for test interpretation. Healthcare workers should adhere to testing algorithms to optimize yield in the appropriate clinical context. Diagnostic assays should follow a sequential, stepwise approach to categorize the toxin expression status of the bacteria accurately.

ESR Essentials: imaging in stable chest pain - practice recommendations by ESCR.

Stable chest pain is a common symptom with multiple potential causes. Non-invasive imaging has an important role in diagnosis and guiding management through the assessment of coronary stenoses, atherosclerotic plaque, myocardial ischaemia or infarction, and cardiac function. Computed tomography (CT) provides the anatomical evaluation of coronary artery disease (CAD) with the assessment of stenosis, plaque type and plaque burden, with additional functional information available from CT fractional flow reserve (FFR) or CT myocardial perfusion imaging. Stress magnetic resonance imaging, nuclear stress myocardial perfusion imaging, and stress echocardiography can assess myocardial ischaemia and other cardiac functional parameters. Coronary CT angiography can be used as a first-line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. Functional testing may be considered for patients with known CAD, where the clinical significance is uncertain based on anatomical testing, or in patients with high pre-test probability. This practice recommendations document can be used to guide the selection of non-invasive imaging for patients with stable chest pain and provides brief recommendations on how to perform and report these diagnostic tests. KEY POINTS: The selection of non-invasive imaging tests for patients with stable chest pain should be based on symptoms, pre-test probability, and previous history. Coronary CT angiography can be used as a first-line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. Functional testing can be considered for patients with known CAD, where the clinical significance of CAD is uncertain based on anatomical testing, or in patients with high pre-test probability. KEY RECOMMENDATIONS: Non-invasive imaging is an important part of the assessment of patients with stable chest pain. The selection of non-invasive imaging test should be based on symptoms, pre-test probability, and previous history. (Level of evidence: High). Coronary CT angiography can be used as a first line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. CT provides information on stenoses, plaque type, plaque volume, and if required functional information with CT fractional flow reserve or CT perfusion. (Level of evidence: High). Functional testing can be considered for patients with known CAD, where the clinical significance of CAD is uncertain based on anatomical testing, or in patients with high pre-test probability. Stress MRI, SPECT, PET, and echocardiography can provide information on myocardial ischemia, along with cardiac functional and other information. (Level of evidence: Medium).

Comparative diagnostic accuracy of transcranial Doppler and contrast-enhanced transthoracic echocardiography for the diagnosis of patent foramen ovale and atrial septal defect.

Recognition of right-to-left shunt is crucial in the work-up of patients with suspected patent foramen ovale (PFO) or atrial septal defect (ASD). While transesophageal echocardiography (TEE) remains the gold standard diagnostic tool for the anatomic assessment of PFO/ASD, transcranial Doppler (TCD) and contrast-enhanced transthoracic echocardiogram (CE-TTE) hold the promise of providing minimally invasive yet accurate clinical details. Their comparative accuracy remains however debated. We conducted a retrospective observational study leveraging our extensive institutional experience with systematic TCD and CE-TTE in patients with suspected PFO/ASD. Several measures of diagnostic test accuracy were computed, with point estimates and 95% confidence intervals, when applicable. A total of 1358 patients were included, with age 48±14 years and 772 (58%) women. Tests were performed for diagnostic purposes in 797 (58.6%) and during follow-up in 740 (54.5%). A PFO was eventually diagnosed in 1038 (77.9%) patients, and an ASD in 60 (4.5%). Agreement between TCD and CE-TTE occurred in 1309 (85.2%) cases, with TCD yielding worse findings than CE-TTE in 91 (5.9%) patients, and vice versa in 137 (8.9%), yielding a Cohen kappa of 78.6% (95% CI: 76.3-81.1%) and a highly significant P value at McNemar test (P<0.001). After dichotomization, and using TCD as benchmark, CE-TTE yielded sensitivity 96.9%, specificity 95.1%, area under the curve 92.1%, and P=0.249. Similar findings were obtained when focusing only on diagnostic tests or follow-up ones (Cohen kappa respectively 74.0% [70.2-77.1%], P<0.001 and 80.3% [76.4-84.3%], P<0.001). Notably, Valsalva was necessary to disclose the presence of shunt during TCD in 487 (31.7%) patients and during CE-TTE in 482 (31.4%) cases. Finally, performance of TCD and CE-TTE in a subset of patients eventually undergoing TTE was quite similar. The diagnostic accuracy of CE-TTE appears favorable, and this imaging test may identify patients who may be missed if only TCD is used to screen patients with suspected PFO/ASD. Accordingly, CE-TTE is recommended as an adjunct diagnostic modality for all patients with a high pre-test probability of PFO/ASD and right-to-left shunt.

Integrating Pre-test Probability and Point-of-Care Ultrasound (POCUS) in the Emergency Department (ED) Diagnosis of Small Bowel Obstruction (SBO).

Introduction A computed tomography (CT) scan and point-of-care ultrasound (POCUS) are commonly employed for diagnosing small bowel obstructions (SBOs). Prior studies demonstrated that POCUS has 90-95% sensitivity and specificity compared with CT scanning, which is the gold standard. Unlike other imaging modalities (in which the ordering and performing clinician are not the same), POCUS-performing/interpreting sonologists must recognize the risk of confirmation bias in the POCUS application. Per Bayesian analysis, the likelihood of a diagnosis being true following a diagnostic test is based on the ordering clinician's pre-test probability and the test characteristics (sensitivity and specificity, from which positive and negative likelihood ratios can be calculated). Consequently, establishing pre-test probability is important in informing downstream diagnostic or therapeutic interventions, as pre-test probability influences post-test odds. Little research has been done on the role of POCUS sonologist's pre-test probability and actual POCUS results regarding SBO. This study assessed the role of POCUS, integrating pre-test probability and POCUS results to determine post-test odds. Methods One hundred six patients were recruited on a convenience basis and underwent POCUS and CT between April 2017 and December 2022. All sonographers were credentialed in POCUS. POCUS sonologists' pre-test probabilities and POCUS and CT results were captured, which were compared. Sensitivity, specificity, LR+, and LR- were calculated, and correlations were made between pre-test probability and POCUS and CT results. Results POCUS exhibited a sensitivity of 92% and specificity of 90%, with a corresponding positive likelihood ratio (LR+) of 9.3 and a negative likelihood ratio (LR-) of 0.09 for diagnosing SBO. Among patients with a high pre-test probability of SBO, a negative ultrasound yielded post-test odds of 0.4%, whereas a positive POCUS yielded post-test odds of 39.6%. Among patients with a low pre-test probability, a negative POCUS resulted in post-test odds of 0%, while a positive POCUS led to post-test odds of 2.1%, yielding a number needed to scan (NNS) of ~50 to identify a patient with an SBO on CT. Conclusion This study confirmed POCUS's sensitivity and specificity of ~90-95% and a corresponding LR+ of 9.2 and LR- of 0.9. Pre-test probability substantially affected post-test odds. Patients with a high pre-test probability and a positive POCUS had post-test odds of 39.6 and should have a confirmatory CT, while those with a negative POCUS have very low post-test odds and very likely will not benefit from CT. Patients with low pre-test probability and a positive POCUS have post-test odds of 2.1%, similar to the Wells Score and HEART score; such patients may not benefit from a CT, though clinicians should use their judgment/discretion. Patients with a low pre-test probability and a negative POCUS have post-test odds of 0% and should not have a CT. Among low pre-test probability patients, the NNS was ~50 to identify patients with an SBO on CT.

Performance of a multigene genomic classifier and clinical parameters in predicting malignancy in a Southeast Asian cohort of patients with cytologically indeterminate thyroid nodules.

Most thyroid nodules are benign. It is important to determine the likelihood of malignancy in such nodules to avoid unnecessary surgery. The primary objective of this study was to characterize the genetic landscape and the performance of a multigene genomic classifier in fine-needle aspiration (FNA) biopsies of cytologically indeterminate thyroid nodules in a Southeast Asian cohort. The secondary objective was to assess the predictive contribution of clinical characteristics to thyroid malignancy. This prospective, multicenter, blinded study included 132 patients with 134 nodules. Molecular testing (MT) with ThyroSeq v3 was performed on clinical or ex-vivo FNA samples. Centralized pathology review also was performed. Of 134 nodules, consisting of 61% Bethesda category III, 20% category IV, and 19% category V cytology, and 56% were histologically malignant. ThyroSeq yielded negative results in 37.3% of all FNA samples and in 42% of Bethesda category III-IV cytology nodules. Most positive samples had RAS-like (41.7%), followed by BRAF-like (22.6%), and high-risk (17.9%) alterations. Compared with North American patients, the authors observed a higher proportion of RAS-like mutations, specifically NRAS, in Bethesda categories III and IV and more BRAF-like mutations in Bethesda category III. The test had sensitivity, specificity, negative predictive value, and positive predictive value of 89.6%, 73.7%, 84.0%, and 82.1%, respectively. The risk of malignancy was predicted by positive MT and high-suspicion ultrasound characteristics according to American Thyroid Association criteria. Even in the current Southeast Asian cohort with nodules that had a high pretest cancer probability, MT could lead to potential avoidance of diagnostic surgery in 42% of patients with Bethesda category III-IV nodules. MT positivity was a stronger predictor of malignancy than clinical parameters.

Assessment of the likelihood of hypothyroidism in dogs diagnosed with and treated for hypothyroidism at primary care practices: 102 cases (2016-2021).

There is a possibility that an incorrect diagnosis of hypothyroidism could be made in euthyroid dogs, and the prevalence of hypothyroidism in the dog population remains unknown. To retrospectively assess the percentage of dogs diagnosed with, and treated for, hypothyroidism at first opinion practice which are likely to be hypothyroid and require levothyroxine supplementation. One hundred two client-owned dogs were included in this study. The computerized databases of 7 first opinion practices were searched to identify dogs treated with levothyroxine supplementation. Three European College of Veterinary Internal Medicine-Companian Animals (ECVIM-CA) diplomates independently assigned 1 of 4 clinical assessments to each case as follows: confirmed or likely hypothyroid, hypothyroidism suspected but not confirmed, hypothyroidism considered unlikely, and no reason to suspect hypothyroidism. They commented as to whether or not they thought levothyroxine supplementation was appropriate. The clinical assessments of "confirmed or likely hypothyroid"; "Hypothyroidism suspected but not confirmed"; "Hypothyroidism considered unlikely"; and "No reason to suspect hypothyroidism" was assigned respectively by Clinician 1 to 38.2%, 5.9%, 3.9%, and 52% of cases, by Clinician 2 to 48%, 22.6%, 22.6%, 6.9% of cases, and by Clinician 3 to 55.9%, 11.8%, 13.7% and 18.6%. Clinician 1, Clinician 2, and Clinician 3 considered levothyroxine supplementation not indicated in 58.8%, 52.9%, and 45.1% of cases, respectively. These results support the concern that hypothyroidism might be overly and incorrectly diagnosed in first opinion practice, and that thyroid function testing should be performed only in those dogs with a high pretest probability of the disease.

Abstract WP127: Diagnostic Value of the Ivy Sign Compared to MR With Cerebrovascular Reactivity in Decompensated Moyamoya Arteriopathy

Introduction: MR cerebrovascular reactivity (CVR) mapping during rapid manipulation of end-tidal pCO2 is used to assess hemodynamic compromise in patients with Moyamoya arteriopathy (MMA). Leptomeningeal ivy sign on MRI FLAIR sequence may indicate regions of decreased perfusion, which would be an inexpensive and easy way to screen for hemodynamic compromise. The purpose of this study was to examine the diagnostic value of the ivy sign compared to MR CVR. Methods: For this retrospective cross-sectional study, we included consecutive patients with uncompensated MMA who were eligible for extracranial-intracranial bypass surgery and completed a preoperative MRI FLAIR with CVR study. Patients with incomplete or artefact degraded imaging were excluded. Two neuroradiologists who were blinded for the CVR result independently assessed the degree of ivy sign on axial 2D FLAIR imaging as grade 0, 1 or 2 in 8 predefined brain regions. Two different readers, blinded for ivy sign, independently assessed the presence or absence of steal in the same regions on MR CVR. Consensus was reached for discordant findings. We assessed interrater agreement using weighted kappa followed by diagnostic accuracy measures for the ivy sign using MR CVR as a reference. Results: We enrolled 73 patients (41/73 (56.1%) female; mean age 43). 47/73 (64%) patients had bilateral MMA with on average 3 brain regions with abnormal CVR. Interrater agreement was good for ivy sign (weighted kappa 0.63 (95%CI 0.54-0.71)) and excellent for CVR (kappa 0.95 (95% CI 0.87-1.00)). For a total of 156/584 (26.7%) brain regions, there was agreement between a positive ivy sign and the presence of steal on CVR and 240/584 (41%) brain regions had no ivy sign and normal CVR. The sensitivity of the ivy sign was 64.5%, specificity 70.2%, positive predictive value 60.5% and negative predictive value 73.6% with an AUC of 0.68 (95% CI 0.64-0.72) Conclusions: In this preselected cohort with high pretest probability for hemodynamic compromise, the diagnostic accuracy of the ivy sign compared to MR CVR was limited and needs to be used with caution to determine haemodynamic status in MMA.