Number Of False Positive Diagnoses Research Articles

High-Field Magnetic Resonance Imaging of the Temporomandibular Joint Low Agreement with Clinical Diagnosis in Asymptomatic Females.

(1) Background: The aim of this study was to investigate the agreement between a clinical diagnosis based on research diagnostic criteria/temporomandibular disorders (RDC/TMD) and high-field magnetic resonance imaging (MRI) findings of temporomandibular joints (TMJs) in asymptomatic females. (2) Methods: A prospective study on 100 females (200 TMJs) was performed, using clinical examinations (RDC/TMD) and same-day MRIs of TMJs on a 3T MR unit. The inclusion criteria were as follows: females, age > 18, the presence of upper and lower incisors, and an understanding of the Serbian language. Descriptive statistics (means and standard deviations) and ANOVA with a post hoc Tukey test for differences among the patient subgroups was performed. The agreement between the clinical and MRI findings was determined using Cohen's kappa coefficient (k < 0.21 slight, 0.21-0.4 fair, 0.41-0.6 moderate, 0.61-0.8 substantial, and 0.81-1 almost perfect). The statistical significance was set at p ≤ 0.05. (3) Results: Normal findings were observed in 86.7%, disc dislocation (DD) was observed in 9.2%, and arthralgia/osteoarthritis/osteoarthrosis was observed in 2.6% of TMJs using RDC/TMD. On the MRI, normal findings were observed in 50.5%, disc dislocation was observed in 16.3%, and arthralgia/osteoarthritis/osteoarthrosis was observed in 23.5% of TMJs. The anterior DD with reduction showed fair agreement of the clinical and MRI findings (k = 0.240, p < 0.001) compared with the DD without reduction (k = 0.355, p < 0.001). Both showed high specificity (94.9% and 99.4%) but low sensitivity (24.2% and 25.0%). The sensitivity in osteoarthritic changes was low (4.8%), but the specificity remained high (96.2%). (4) Conclusions: The sensitivity of the clinical examination remains low compared with 3T MRI, especially in osteoarthritic changes and anterior DD with reduction. However, the number of false positive diagnoses using RDC/TMD is low in asymptomatic patients. RDC/TMD remains a sensible method for establishing a clinical diagnosis and avoiding the overtreatment of asymptomatic patients.

PO-02-225 LATE GADOLINIUM ENHANCEMENT AT CARDIAC MAGNETIC RESONANCE YIELDS HIGH NUMBER OF FALSE POSITIVE DIAGNOSES IN ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY

New diagnostic criteria have been proposed for arrhythmogenic right ventricular cardiomyopathy (ARVC). These proposed “Padua criteria” include late gadolinium enhancement (LGE) on cardiac magnetic resonance for the left ventricle (LV) and right ventricle (RV). Yet, the potential of LGE to distinguish ARVC from differential diagnoses remains unknown. Assess the diagnostic value of LGE to distinguish ARVC from its differentials. We included 130 subjects (57% male, 46±17 years) clinically diagnosed with ARVC as per 2010 Task Force Criteria (n=32, 84% PKP2 carriers), familial dilated cardiomyopathy as per World Health Organization criteria (n=25), myocarditis as per 2013 ESC position statement (n=13), sarcoidosis as per 2014 HRS expert consensus statement (n=20), biopsy-proven cardiac amyloidosis (n=19) and RV outflow tract-ventricular tachycardia (n=21). Presence and distribution of LGE was evaluated by an experienced radiologist using a 17-segment LV and 7-segment RV model. Presence of LGE was determined as per Padua criteria. Diagnostic value of RV-LGE and LV-LGE as per Padua criteria in ARVC vs. non-ARVC patients was evaluated with specificity, false positive rate (FPR) and accuracy. Distributions of LGE per subgroup are shown in the Figure. The RV-LGE criterion was equally often fulfilled in ARVC (n=16, 50%) vs. non-ARVC (n=43, 44%) patients, p=0.546. ARVC patients most often had RV-LGE in the RV inlet region (n=14/32, 44%). Consequently, the RV-LGE criterion yielded specificity 56%, FPR 44% and accuracy 55% for right-sided disease. In contrast, the LV-LGE criterion was significantly more often fulfilled in non-ARVC (n=71, 72%) vs. ARVC (n=11, 34%) patients, p<0.001. ARVC patients most often had LV-LGE in the inferolateral (n=10/11, 91%) wall, whereas it was more global in non-ARVC groups (median segments n=2 [IQR 2-6] ARVC vs. n=9 [IQR 4-15] non-ARVC, p<0.001). As such, the LV-LGE criterion yielded specificity 28%, FPR 72% and accuracy 29% for left-sided disease. LV-LGE is observed in one-third of ARVC patients, most often in the inferolateral region. RV-LGE is observed in half of ARVC patients, typically in the RV inlet region. Notably, LGE is often present in ARVC differentials. While LGE may be helpful to determine focal fibrosis, it may result in a large number of false positive diagnoses when included as a diagnostic criterion. Knowledge of LGE patterns can be useful for diagnostic classification.

Glaucoma diagnostic performance of macular ganglion cell complex thickness using regular and long axial length normative databases

The risks of misdiagnosing a healthy individual as glaucomatous or vice versa may be high in a population with a large majority of highly myopic individuals, due to considerable morphologic variability in high myopic fundus. This study aims to compare the diagnostic ability of the regular and long axial length databases in the RS-3000 Advance SD-OCT (Nidek) device to correctly diagnose glaucoma with high myopia. Patients with high myopia (axial length ≥ 26.0 mm) in Chang Gung Memorial Hospital, Taiwan between 2015 and 2020 were included. Glaucoma was diagnosed based on glaucomatous discs, visual field defects and corresponding retinal nerve fiber layer defects. The sensitivity, specificity, diagnostic accuracy and likelihood ratios of diagnosing glaucoma via mGCC thickness in both superior/inferior and GChart mapping using the regular and long axial length normative databases. The specificity and diagnostic accuracy of mGCC thickness for distinguishing glaucomatous eyes from nonglaucomatous eyes among highly myopic eyes were significantly improved using the long axial length database (p = 0.046). There were also significant proportion changes in S/I mapping as well as GChart mapping (37.3% and 48.0%, respectively; p < 0.01) from abnormal to normal in the myopic normal eye group when using the long axial length normative database. The study revealed that clinicians could utilize a long axial length database to effectively decrease the number of false-positive diagnoses or to correctly identify highly myopic normal eyes misdiagnosed as glaucomatous eyes.

Quantitative comparison of SARS-CoV-2 nucleic acid amplification test and antigen testing algorithms: a decision analysis simulation model

BackgroundAntigen tests for SARS-CoV-2 offer advantages over nucleic acid amplification tests (NAATs, such as RT-PCR), including lower cost and rapid return of results, but show reduced sensitivity. Public health organizations recommend different strategies for utilizing NAATs and antigen tests. We sought to create a framework for the quantitative comparison of these recommended strategies based on their expected performance.MethodsWe utilized a decision analysis approach to simulate the expected outcomes of six testing algorithms analogous to strategies recommended by public health organizations. Each algorithm was simulated 50,000 times in a population of 100,000 persons seeking testing. Primary outcomes were number of missed cases, number of false-positive diagnoses, and total test volumes. Outcome medians and 95% uncertainty ranges (URs) were reported.ResultsAlgorithms that use NAATs to confirm all negative antigen results minimized missed cases but required high NAAT capacity: 92,200 (95% UR: 91,200-93,200) tests (in addition to 100,000 antigen tests) at 10% prevalence. Selective use of NAATs to confirm antigen results when discordant with symptom status (e.g., symptomatic persons with negative antigen results) resulted in the most efficient use of NAATs, with 25 NAATs (95% UR: 13-57) needed to detect one additional case compared to exclusive use of antigen tests.ConclusionsNo single SARS-CoV-2 testing algorithm is likely to be optimal across settings with different levels of prevalence and for all programmatic priorities. This analysis provides a framework for selecting setting-specific strategies to achieve acceptable balances and trade-offs between programmatic priorities and resource constraints.

Evaluation of pool-based testing approaches to enable population-wide screening for COVID-19.

ObjectiveRapid testing is paramount during a pandemic to prevent continued viral spread and excess morbidity and mortality. This study investigates whether testing strategies based on sample pooling can increase the speed and throughput of screening for SARS-CoV-2, especially in resource-limited settings.MethodsIn a mathematical modelling approach conducted in May 2020, six different testing strategies were simulated based on key input parameters such as infection rate, test characteristics, population size, and testing capacity. The situations in five countries were simulated, reflecting a broad variety of population sizes and testing capacities. The primary study outcome measurements were time and number of tests required, number of cases identified, and number of false positives.FindingsThe performance of all tested methods depends on the input parameters, i.e. the specific circumstances of a screening campaign. To screen one tenth of each country’s population at an infection rate of 1%, realistic optimised testing strategies enable such a campaign to be completed in ca. 29 days in the US, 71 in the UK, 25 in Singapore, 17 in Italy, and 10 in Germany. This is ca. eight times faster compared to individual testing. When infection rates are lower, or when employing an optimal, yet more complex pooling method, the gains are more pronounced. Pool-based approaches also reduce the number of false positive diagnoses by a factor of up to 100.ConclusionsThe results of this study provide a rationale for adoption of pool-based testing strategies to increase speed and throughput of testing for SARS-CoV-2, hence saving time and resources compared with individual testing.

Base rate of ovarian cancer on algorithms in patients with a pelvic mass

ObjectiveAlgorithms have been developed to identify ovarian cancer in women with a pelvic mass. The aim of this study was to determine how the base rates of ovarian cancer influence...

Automatic diagnosis of strict left bundle branch block using a wavelet-based approach.

Patients with left bundle branch block (LBBB) are known to have a good clinical response to cardiac resynchronization therapy. However, the high number of false positive diagnosis obtained with the conventional LBBB criteria limits the effectiveness of this therapy, which has yielded to the definition of new stricter criteria. They require prolonged QRS duration, a QS or rS pattern in the QRS complexes at leads V1 and V2 and the presence of mid-QRS notch/slurs in 2 leads within V1, V2, V5, V6, I and aVL. The aim of this work was to develop and assess a fully-automatic algorithm for strict LBBB diagnosis based on the wavelet transform. Twelve-lead, high-resolution, 10-second ECGs from 602 patients enrolled in the MADIT-CRT trial were available. Data were labelled for strict LBBB by 2 independent experts and divided into training (n = 300) and validation sets (n = 302) for assessing algorithm performance. After QRS detection, a wavelet-based delineator was used to detect individual QRS waves (Q, R, S), QRS onsets and ends, and to identify the morphological QRS pattern on each standard lead. Then, multilead QRS boundaries were defined in order to compute the global QRS duration. Finally, an automatic algorithm for notch/slur detection within the QRS complex was applied based on the same wavelet approach used for delineation. In the validation set, LBBB was diagnosed with a sensitivity and specificity of Se = 92.9% and Sp = 65.1% (Acc = 79.5%, PPV = 74% and NPV = 89.6%). The results confirmed that diagnosis of strict LBBB can be done based on a fully automatic extraction of temporal and morphological QRS features. However, it became evident that consensus in the definition of QRS duration as well as notch and slurs definitions is necessary in order to guarantee accurate and repeatable diagnosis of complete LBBB.

Diagnostic challenges in epilepsy

Epileptic seizures and epilepsy are part of daily clinical practice in neurology. Yet, the number of false positive diagnoses is surprisingly high. Almost one out of every five patients treated for epilepsy does not really have this diagnosis, which is a high percentage bearing in mind the social and medical consequences that being diagnosed with epilepsy entails. To summarise the most important diagnostic challenges in epilepsy, to describe possible sources of diagnostic error and to offer advice on how to avoid them. Epilepsy is characterised by a tendency to suffer unprovoked epileptic seizures. The greatest obstacle when it comes to diagnosing a case of epilepsy is the fact that epileptic seizures are transient phenomena that occur relatively infrequently and the physician who must carry out the diagnosis will rarely see them. Moreover, there are other clinical events, such as syncopes or non-epileptic seizures, that may be similar to epileptic seizures in appearance and, consequently, can be mistaken for them. Finally, when interpreting the two most important complementary diagnostic techniques in epileptology, the electroencephalogram and magnetic resonance imaging of the brain, the most common errors must be taken into account in order to prevent mistaken diagnoses. The diagnosis of epilepsy is a challenge and must be based on a detailed and specific medical record. If there are any reasonable doubts, from the outset, about the diagnosis of epilepsy or if the patient does not respond well to the antiepileptic treatment, we recommend referring the patient to a specialised centre to establish a definitive diagnosis.

What’s Wrong with Me? What’s Wrong with You? The Issue of Over-Diagnosing ADHD in Children

Historically, the field of mental health has been shrouded in controversy and conflict. The problems associated with diagnosing mental illnesses are still prevalent today, and this process becomes even more complicated when assessing children, who have yet to develop mature social skills and cognitive functioning. Attention deficit hyperactivity disorder (ADHD) is one of the mental health conditions that is diagnosed using the Diagnostic and Statistical Manual of Mental Disorders (DSM). Overwhelming support from the primary literature suggests that the current procedures of diagnosing ADHD- which begin during childhood- allow for a high degree of subjectivity, inconsistency, and uncertainty. For these reasons, the issue of over-diagnosing ADHD in children has become more significant, and more plausible than ever before. By outlining the key factors that contribute to this problem, certain modifications can be made to improve the ADHD diagnostic procedures for future applications. These changes can increase the accuracy of mental health assessments, thus minimizing the number of false positive diagnoses of ADHD in children worldwide.

Investigating the impact of TB case-detection strategies and the consequences of false positive diagnosis through mathematical modelling

BackgroundIncreasing case notifications is one of the top programmatic priorities of National TB Control Programmes (NTPs). To find more cases, NTPs often need to consider expanding TB case-detection activities to populations with increasingly low prevalence of disease. Together with low-specificity diagnostic algorithms, these strategies can lead to an increasingly high number of false positive diagnoses, which has important adverse consequences.MethodsWe apply TIME, a widely-used country-level model, to quantify the expected impact of different case-finding strategies under two scenarios. In the first scenario, we compare the impact of implementing two different diagnostic algorithms (higher sensitivity only versus higher sensitivity and specificity) to reach programmatic screening targets. In the second scenario, we examine the impact of expanding coverage to a population with a lower prevalence of disease. Finally, we explore the implications of modelling without taking into consideration the screening of healthy individuals. Outcomes considered were changes in notifications, the ratio of additional false positive to true positive diagnoses, the positive predictive value (PPV), and incidence.ResultsIn scenario 1, algorithm A of prolonged cough and GeneXpert yielded fewer additional notifications compared to algorithm B of any symptom and smear microscopy (n = 4.0 K vs 13.8 K), relative to baseline between 2017 and 2025. However, algorithm A resulted in an increase in PPV, averting 2.4 K false positive notifications thus resulting in a more efficient impact on incidence. Scenario 2 demonstrated an absolute decrease of 11% in the PPV as intensified case finding activities expanded into low-prevalence populations without improving diagnostic accuracy, yielding an additional 23 K false positive diagnoses for an additional 1.3 K true positive diagnoses between 2017 and 2025. Modelling the second scenario without taking into account screening amongst healthy individuals overestimated the impact on cases averted by a factor of 6.ConclusionOur findings show that total notifications can be a misleading indicator for TB programme performance, and should be interpreted carefully. When evaluating potential case-finding strategies, NTPs should consider the specificity of diagnostic algorithms and the risk of increasing false-positive diagnoses. Similarly, modelling the impact of case-finding strategies without taking into account potential adverse consequences can overestimate impact and lead to poor strategic decision-making.

One or two serological assay testing strategy for diagnosis of HBV and HCV infection? The use of predictive modelling

BackgroundInitial serological testing for chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection is conducted using either rapid diagnostic tests (RDT) or laboratory-based enzyme immunoassays (EIA)s for detection of hepatitis B surface antigen (HBsAg) or antibodies to HCV (anti-HCV), typically on serum or plasma specimens and, for certain RDTs, capillary whole blood. WHO recommends the use of standardized testing strategies – defined as a sequence of one or more assays to maximize testing accuracy while simplifying the testing process and ideally minimizing cost. Our objective was to examine the diagnostic outcomes of a one- versus two-assay serological testing strategy. These data were used to inform recommendations in the 2017 WHO Guidelines on hepatitis B and C testing.MethodsFew published studies have compared diagnostic outcomes for one-assay versus two-assay serological testing strategies for HBsAg and anti-HCV. Therefore, the principles of Bayesian statistics were used to conduct a modelling exercise to examine the outcomes of a one-assay versus two-assay testing strategy when applied to a hypothetical population of 10,000 individuals. The resulting model examined the diagnostic outcomes (true and false positive diagnoses; true and false negative diagnoses; positive and negative predictive values as a function of prevalence; and total tests required) for both one-assay and two-assay testing strategies. The performance characteristics assumed for assays used within the testing strategies were informed by WHO prequalification assessment findings and systematic reviews for diagnostic accuracy studies. Each of the presumptive testing strategies (one-assay or two-assay) was modelled at varying prevalences of HBsAg (10%, 2% and 0.4%) and of anti-HCV (40%, 10%, 2% and 0.4%), aimed at representing the range of testing populations typically encountered in WHO Member States. When the two-assay testing strategy was considered, the model assumed the independence of the two assays.ResultsModeling demonstrated that applying a single assay (HBsAg or anti-HCV), even with high specificity (99%), may result in considerable numbers of false positive diagnoses and low positive predictive values (PPV), particularly in lower prevalence settings. Even at very low prevalences shifting to a two-assay testing strategy would result in a PPV approaching 1.0. When test sensitivity is high (>99%) false negative reactions are rare at all but the highest prevalences; but a two-test strategy might yield more false negative diagnoses. The order in which the tests are used has no impact on the overall accuracy of a two-assay strategy though it may impact the total number of tests needed to complete the diagnostic strategy, incurring added cost and complexity. HBsAg assays may have a low sensitivity (<90%), and result in large numbers of false negative diagnoses, particularly in high prevalence settings, which would be exacerbated in the two-assay testing strategy. In contrast, most anti-HCV assays have high sensitivity and lead to fewer false negative results, both in the one-assay and two-assay testing strategies. At prevalences ≤2% the number of tests needed using a second assay was nearly always small, at <300 per 10,000 individuals tested, making sustainability of a second assay uncertain in such a setting.ConclusionsA key public health objective of an effective testing strategy is to identify all individuals who would benefit from treatment. Therefore, a strategy that prioritizes a high NPV (minimal false negatives) may be acceptable even if the PPV is suboptimal (some false positives) as the implementation of such a public health programme must also take account of other factors such as costs, feasibility, impact on testing uptake and linkage to care, and consequences of a false-positive test. This rationale informed the development of the WHO Viral Hepatitis Testing Guidelines, with a conditional recommendation for a one-assay serological testing strategy in most testing settings and populations (≥0.4% prevalence in population tested). A one-test strategy results in few failures to diagnose infection and, although it is associated under most assumptions with a sub-optimal PPV, benefits include greater simplicity, easier implementation, lower costs and better feasibility, uptake and linkage to care. Furthermore, prior to antiviral therapy all those diagnosed either HBsAg or anti-HCV positive will require confirmation of viræmia, preventing unnecessary treatment of those who may be false positive on serology. For HBsAg, in low-prevalence settings (≤0.4%), a second recommendation was made to consider a two-assay testing strategy, using a confirmatory neutralization step or a second different HBsAg assay.

MR Imaging of Pulmonary Nodules: Detection Rate and Accuracy of Size Estimation in Comparison to Computed Tomography.

ObjectiveThe aims of this study were to assess the sensitivity of various magnetic resonance imaging (MRI) sequences for the diagnosis of pulmonary nodules and to estimate the accuracy of MRI for the measurement of lesion size, as compared to computed tomography (CT).MethodsFifty patients with 113 pulmonary nodules diagnosed by CT underwent lung MRI and CT. MRI studies were performed on 1.5T scanner using the following sequences: T2-TSE, T2-SPIR, T2-STIR, T2-HASTE, T1-VIBE, and T1-out-of-phase. CT and MRI data were analyzed independently by two radiologists.ResultsThe overall sensitivity of MRI for the detection of pulmonary nodules was 80.5% and according to nodule size: 57.1% for nodules ≤4mm, 75% for nodules >4-6mm, 87.5% for nodules >6-8mm and 100% for nodules >8mm. MRI sequences yielded following sensitivities: 69% (T1-VIBE), 54.9% (T2-SPIR), 48.7% (T2-TSE), 48.7% (T1-out-of-phase), 45.1% (T2-STIR), 25.7% (T2-HASTE), respectively. There was very strong agreement between the maximum diameter of pulmonary nodules measured by CT and MRI (mean difference -0.02 mm; 95% CI –1.6–1.57 mm; Bland-Altman analysis).ConclusionsMRI yielded high sensitivity for the detection of pulmonary nodules and enabled accurate assessment of their diameter. Therefore it may be considered an alternative to CT for follow-up of some lung lesions. However, due to significant number of false positive diagnoses, it is not ready to replace CT as a tool for lung nodule detection.

Can computed tomography esophagography reliably diagnose traumatic penetrating upper digestive tract injuries?

ObjectiveTo determine the sensitivity and specificity of computed tomography (CT) esophagography in diagnosing penetrating esophageal and hypopharyngeal injuries in trauma patients and to see if it can be used as the only imaging method in diagnosing these injuries. The confidence of radiologists using only CT esophagography was also measured. Patients and methodsA prospective cross-sectional analytic study was done on haemodinamically stable patients requiring multidetector CT after external penetrating neck or chest trauma. Each patient was given oral contrast consisting of 50 ml 50% iohexol solution, within 5 min of commencement of the CT examination and in the supine position. An attempt was made to confirm all CT esophagography findings with at least one secondary method. Images were evaluated separately by two general departmental radiologists who were blinded to the results of the confirmation method. ResultsBetween December 2012 and November 2014, 102 patients were included, of which 93 (91.2%) were male. Stab wounds were responsible for 85.3% (n=87) of penetrating wounds. Ninety-four patients (92.2%) had CT angiography (CTA) in conjunction with CT esophagography. There were 20 confirmed upper digestive tract injuries; 11 (55.0%) in the hypopharynx and 9 (45.0%) in the esophagus. With the exception of one case, all upper digestive tract injuries were diagnosed using only CT esophagography. No upper digestive tract injuries were correctly identified in 70 and 75 out of 82 true negative cases respectively, suggesting a sensitivity of 95.0% for both radiologists and specificity of 85.4% and 91.5% for CT esophagography. A number of false positive diagnoses were reported when CT esophagography was done in conjunction with CTA, resulting in a positive predictive value of 61.3% and 79.1% for this technique. Reviewers were positive to very confident about the CT esophagography findings in 90.0% and 100% of patients with injuries and 79.0% and 87.0%, respectively, in the no injury group. ConclusionCT esophagography is reliable in diagnosing penetrating upper digestive tract injuries. In conjunction with CTA, false positive findings may occur. Radiologists were generally positive to very confident about their CT esophagography findings, not needing further imaging in more than 60% of cases.

EXPERIENCE OF VIDEOTHORACOSCOPY (VTS) IN THORACIC ONCOLOGY DIAGNOSIS AND TREATMENT OF SMALL LUNG NEOPLASMS

Hyperdiagnosis of lung cancer in recent years is of concern because of the emergence of new screening methods that detect small nodules, which clinical significance is unknown. The incidence of lung cancer ranged from 0.4% to 2.7% according to the results of screening studies, depending on the size of the population surveyed. The large number of false-positive diagnoses is unsolved problem yet. At the initial stage of the examination in the groups with high risk the number of false diagnoses is in the range of 10-20%, but can reach 50%, with positive predictive values of 2.8% to 11.6%. It is found that pathological nodules less than5 mmare unlikely malignant, and nodules from 5 to10 mmin diameter are undefined, 25-40% of which contain calcifications. Management of patients with such nodules, as a rule, is to perform repeated CT scans over time and if the growth of nodules is detected then fine-needle aspiration biopsy or surgical resection must be performed. Videothoracoscopy with biopsy provides a high efficiency in differential diagnosis of single tumors located in the cortical and subcortical regions of the lung or near the interlobar fissure. Presented here results indicate that the current VTS in peripheral tumors and metastatic lesions of the lung is the only minimally invasive method to verify the process with 100% accuracy.

Effect of glomerular filtration rate impairment on diagnostic performance of neutrophil gelatinase-associated lipocalin and B-type natriuretic peptide as markers of acute cardiac and renal failure in chronic kidney disease patients

IntroductionCardio-renal syndromes are characterized by the impairment of cardiac and renal functions. Plasma and urinary neutrophil gelatinase-associated lipocalin (NGAL), and plasma B-type natriuretic peptide (BNP) are markers of acute kidney injury (AKI) and heart failure (HF), respectively.The aim of this study was to assess the effect of the reduction of glomerular filtration rate (GFR) on plasma BNP and on plasma and urinary NGAL concentrations in stable chronic kidney disease (CKD) patients at different functional stages.MethodsGFR (99mTc-DTPA), plasma BNP, and plasma and urinary concentrations of NGAL were measured in 310 clinically stable CKD patients, at functional stages from 1 to 5. Serum and urinary low-molecular-weight proteins cystatin C and β2-microglobulin, and urinary tubular enzymes were measured for comparison. Plasma BNP, NGAL, cystatin C and β2-microglobulin were measured also in 31 maintenance hemodialysis patients.ResultsPlasma NGAL increased with the reduction of GFR in CKD patients from stage 2. In the different CKD stages modest differences were found for BNP values. Urinary NGAL increased slightly but significantly in patients at CKD stages 4 and 5, similarly to urinary cystatin C and β2-microglobulin. In maintenance hemodialysis patients, plasma NGAL and BNP were markedly increased, and high-flux hemodialysis significantly decreased their plasma concentrations.ConclusionsPlasma NGAL increases markedly with the reduction in GFR, generating a very high number of false positive diagnoses of AKI in stable CKD patients. The grade of GFR impairment and the cause of kidney disease have a lower effect on urinary NGAL and on plasma BNP. In any case, specific reference values of NGAL and BNP should be used in chronic kidney disease patients, according to their functional stage, when assessing acute kidney injury, heart failure, and cardio-renal syndromes in patients with impaired GFR.

Accuracy of Magnetic Resonance Imaging of the Knee in the Community Setting

Background:Magnetic resonance imaging (MRI) is routinely used in the diagnosis of sports-related knee injuries.Purpose:To determine the accuracy, sensitivity, and specificity of MRI compared with clinical evaluation in the diagnosis of meniscal pathology when the MRI facility and the radiologist are not preselected.Methods:A total of 288 knee arthroscopies were retrospectively compared. Patients were divided into 3 groups: those who had MRI performed and interpreted at a single institution, MRI performed and interpreted at community facilities, or a clinical evaluation by a senior orthopaedic surgeon.Results:The sensitivity, specificity, and accuracy of the diagnosis of medial meniscal pathology at a single institution were 90%, 59%, 76%; in community facilities, 73%, 68%, 70%; and by a clinical evaluation, 93%, 55%, 73%, respectively. For lateral meniscal pathology, the results were as follows: single institution, 75%, 76%, 81%; community facilities, 60%, 88%, 79%; and clinical evaluation, 45%, 90%, 79%, respectively. Sensitivity for medial meniscus was greater than for lateral meniscus, but specificity of diagnosis was better for lateral meniscus by MRI and clinical evaluation. While not statistically significant, there was increased sensitivity in the diagnosis of medial meniscus and lateral meniscus at SIs, but they have less specificity than at community facilities. The number of false-positive diagnoses (ie, no intra-articular pathology) that resulted in surgery was 4 of 288 (1.39%). The overall accuracy for medial meniscus by MRI was 73% vs 73% for clinical evaluation. The overall accuracy for MRI for lateral meniscus was 78% vs 79% for clinical evaluation.Conclusion:Routine MRI may not be more beneficial than clinical evaluation when there is no preselection of MRI facility and interpreting radiologist.Clinical Relevance:The use of MRI for diagnosing meniscal pathology should be reserved for those cases where the orthopaedic clinical examination is ambiguous.

The DSM-5’s Proposed New Categories of Sexual Disorder: The Problem of False Positives in Sexual Diagnosis

The proposals that have emerged from the DSM-5 revision process have triggered considerable controversy, especially regarding potential invalid inflation of diagnostic categories. To illustrate the kinds of issues that have emerged, I closely examine the proposed new categories of sexual disorder. The DSM-5 Sexual and Gender Identity Disorders Work Group is proposing the addition of three categories of disorder to the DSM-5—hypersexuality, hebephilia (as part of a revised pedophilia category that would become pedohebephilia), and coercive paraphilic disorder (basically a “nonconsent” or rape paraphilia). These proposals are driven by perceived clinical or forensic needs. I argue, however, that their conceptual soundness remains problematic; each could lead to large numbers of false positive diagnoses (i.e., diagnoses that mistakenly label a normal variant of behavior as a mental disorder), with potential for serious forensic abuse in “sexually violent predator” civil commitment proceedings.

Sickle cell anemia pathophysiology: Back to the data

Sickle cell anemia pathophysiology: Back to the data

Placenta accreta : fréquence, dépistage prénatal, prise en charge

In the last 30 years, incidence of placenta accreta has dramatically increased to reach an alarming rate of more than one in 2500 deliveries. The rate of placenta accreta increased in conjunction with cesarean deliveries. 2D-ultrasonography is an useful tool to diagnose placenta accreta. The most reliable sign is the presence of abnormal placental lacunae. The lack of visualization of the echolucent area between the placenta and the myometrium with no other ultrasound finding has a poor sensitivity and positive predictive value. 3D power Doppler is useful to increase the diagnostic performance of 2D-ultrasonography. The presence of at least two ultrasound findings decreases the number of false-positive diagnosis and increases the performance of both 2D-ultrasonography and 3D power Doppler. Magnetic resonance imaging in cases with inconclusive ultrasound features optimizes diagnostic accuracy. In cases of prenatal diagnosis of placenta accreta, extirpative method should be to date abandoned. Advantages and disadvantages of both cesarean-hysterectomy and conservative treatment should be clearly explained to the patient and her partner, who have to be involved in the decision process. Currently, it seems to be reasonable to propose a cesarean-hysterectomy to multiparous patients with no desire of future pregnancy. In young women who want the option of future pregnancy and who agree to close follow-up monitoring, conservative treatment should be preferred. When placenta accreta is diagnosed during the delivery, the two options remain possible only if attempts of removal of the placenta are stopped before the occurrence of a severe postpartum hemorrhage. In cases of placenta percreta with bladder involvement, conservative treatment may be the optimal management.

Rapid detection of laboratory cross-contamination with Mycobacterium tuberculosis using multispacer sequence typing

BackgroundThe ability to culture Mycobacterium tuberculosis from clinical specimens serves as the gold standard for the diagnosis of tuberculosis. However, a number of false-positive diagnoses may be due to cross-contamination of such specimens. We herein investigate such episode of cross-contamination by using a technique known as multispacer sequence typing (MST). This technique was applied to six M. tuberculosis isolates prepared within the same laboratory over a two-week period of time.ResultsMST analysis indicated a unique and common sequence profile between a strain isolated from a patient with proven pulmonary tuberculosis and a strain isolated from a patient diagnosed with lung carcinoma. Using this approach, we were able to provide a clear demonstration of laboratory cross-contamination within just four working days. Further epidemiological investigations revealed that the two isolates were processed for culture on the same day.ConclusionThe application of MST has been demonstrated to serve as a rapid and efficient method to investigate cases of possible cross-contamination with M. tuberculosis.