Clinical and Echocardiographic Characterization of False-Positive Results from Stress Echocardiography

Rui Azevedo Guerreiro,Paula Fazendas,Ana Rita Pereira,Ana Marques,João Pais,Sofia Alegria,Kisa Hyde Congo,Ana Catarina Gomes,João Carvalho,Gonçalo Morgado,Inês Cruz,Ana Rita Almeida,Isabel João,Hélder 한국심초음파학회 2020 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.28 No.2

BACKGROUND: Stress echocardiography has a 72%–85% sensitivity and an 80%–95% specificity. In this study, we characterized patients who received a false-positive stress echocardiogram result. METHODS: A total of 5,256 patients underwent a stress echocardiogram (induced by exercise, dobutamine, or dipyridamole) between 2009 to 2018, and 405 patients (7.7%) received a positive result. Among the positive patients, 300 underwent coronary angiography within 12 months, and these patients were included in this study (mean age = 64.9 ± 9.4 years, 230 men [76.7%]). Coronary artery disease was diagnosed by stenosis ≥50% in any epicardial coronary artery. Clinical and echocardiographic variables were compared between patients with true- and false-positive stress echocardiogram results. RESULTS: Seventy-two patients (24%) had a false-positive stress echocardiogram, with similar rates across stressor types (p = 0.574). Patients with false positives were less frequently men (63.9% vs. 80.7%, p = 0.003), had lower diabetes mellitus prevalence (15.3% vs. 45.6%, p = 0.001), were similar to true positive patients with regard to body-mass index, arterial hypertension prevalence, hyperlipidemia and smoking, and had lower pre-test probability of coronary artery disease (23% vs. 32%, p = 0.016). The wall motion score index (WMSI) was higher in the true-positive stress group, and wall motion abnormalities were more frequent in the apical segments (70.5% vs. 56.7%, p = 0.034). In a multivariable predictive model, men (odds ratio [OR] = 2.994), diabetes (OR = 5.440), and peak WMSI (OR = 10.690) were associated with a true-positive result. CONCLUSIONS: Twenty-four percent of our study population received a false-positive stress echocardiogram result, with similar rates across stressor types. Patients with true-positive stress echocardiogram results are more likely to be men, diabetic, and have a high peak WMSI.

자기공명혈관촬영상 가양성 두개내동맥류: 함정의 원인

박보람,류창우,김의종,최우석,이덕희 대한영상의학회 2007 대한영상의학회지 Vol.57 No.4

목적: 자기공명혈관촬영(MR angiography, 이하 MRA)에서 두개내동맥류로 오진할 수 있는 함정에 대해 알아보고자 한다. 대상과 방법: MRA에서 우연히 발견된 두개내동맥류로 진단받은 210예를 후향적으로 분석하였다. 이들은 모두 확진을 위하여 CT 혈관조영술(CT angiography, 이하 CTA)이나 디지털감산 혈관조영술(digital subtraction angiography, 이하 DSA)을 시행 받았으며 이 중 가양성으로 판명된 예들의 빈도, 병변의 위치, 크기, 원인 등을 조사하였다. 결과: 210명 중 28명이 CTA나 DSA로 가양성 동맥류를 확진 받았다. 이들은 중뇌동맥(n=9, 분지부: 7, 본체: 2)과 전교통동맥(n=5)에 주로 위치 했으며 대부분의(78.6%) 병변의 최대 직경은 3 mm 이하였다. 원인은 접합부 팽대(n=14), 혈관의 사행성 (n=6), 정상변이 (n=3), 원인미상(n=3) 등 이었다. 결론: MRA에서 가양성 두개내동맥류의 가능성과 함정을 이해하는 것은 선별 MRA의 진단 정확도를 증가시키는데 도움을 줄 것이며 불필요한 침습적 검사를 줄이는데 기여할 것이다. Purpose: The purpose of this study is to analyze the incidence and causes of false-positive intracranial aneurysms on MR angiography (MRA). Materials and Methods: We retrospectively evaluated 210 cases that were incidentally diagnosed as intracranial aneurysms on MRA. All the cases were confirmed by CT angiography (CTA) or digital subtraction angiography (DSA). We investigated the incidence, location, size, and causes of the false-positive aneurysms on MRA. Results: Of 210 cases, 28 cases were confirmed as false-positive aneurysms. Most of the lesions were located on the middle cerebral artery (n = 9, 7 lesions located in the bifurcation and 2 lesions located in the trunk) and the anterior communicating artery (n = 5). The diameters of most of the lesions (78.6%) were smaller than 3 mm. Causes were junctional dilatation (n = 14), vascular tortuosity (n = 6), normal variation (n = 3) and unknown causes (n = 3). Conclusion: Understanding the risks and pitfalls of false-positive intracranial aneurysms determined on MRA would be helpful for improving the diagnostic accuracy of screening MRA and for reducing the number of unnecessary invasive examinations.

Etiologies and Predictors of ST-Segment Elevation Myocardial Infarction

배명환,조용근,천상수,송준혁,장세영,최원석,김균희,박선희,이장훈,양동헌,박헌식,채성철 대한심장학회 2013 Korean Circulation Journal Vol.43 No.6

Background and Objectives: Rapid diagnosis of ST-segment elevation myocardial infarction (STEMI) is essential for the appropriate management of patients. We investigated the prevalence, etiologies and predictors of false-positive diagnosis of STEMI and subsequent inappropriate catheterization laboratory activation in patients with presumptive diagnosis of STEMI. Subjects and Methods: Four hundred fifty-five consecutive patients (62 ±13 years, 345 males) with presumptive diagnosis of STEMI be-tween August 2008 and November 2010 were included. Results: A false-positive diagnosis of STEMI was made in 34 patients (7.5%) with no indication of coronary artery lesion. Common causes for the false-positive diagnosis were coronary spasm in 10 patients, left ventricular hypertrophy in 5 patients, myocarditis in 4 patients, early repolarization in 3 patients, and previous myocardial infarction and stress-induced cardiomyopathy in 2 patients each. In multivariate logistic regression analysis, symptom-to-door time >12 hours {odds ratio (OR) 4.995, 95% confidence interval (CI) 1.384-18.030, p=0.014 }, pre-senting symptom other than chest pain (OR 7.709, 95% CI 1.255-39.922, p=0.027), absence of Q wave (OR 9.082, CI 2.631-31.351, p<0.001)and absence of reciprocal changes on electrocardiography (ECG) (OR 17.987, CI 5.295-61.106, p<0.001) were independent predictors of false-positive diagnosis of STEMI. Conclusion: In patients whom STEMI was planned for primary coronary intervention, the false-positive diagnosis of STEMI was not rare. Correct interpretation of ECGs and consideration of ST-segment elevation in conditions other than STEMI may reduce inappropriate cathe-terization laboratory activation.

False-Positive Hypermetabolic Lesions on Post-Treatment PET-CT after Influenza Vaccination

( Jeong Eun Kim ),( Eun Kyoung Kim ),( Dae Ho Lee ),( Sang We Kim ),( Cheol Won Suh ),( Jung Shin Lee ) 대한내과학회 2011 The Korean Journal of Internal Medicine Vol.26 No.2

We report a case of a 59-year-old man with testicular germ cell tumor who showed new hypermetabolic lesions at the left axillary lymph nodes on a post-treatment positron emission tomography-computed tomography (PET-CT) scan. The hypermetabolic lesions were found to be caused by an influenza vaccination 10 days prior to the PET-CT scan and disappeared without additional treatment. To date, he is alive with complete remission. (Korean J Intern Med 2011;26:210-212)

False-Positive Radioactive Iodine Uptake Mimicking Miliary Lung Metastases in a Patient Affected by Papillary Thyroid Cancer and IgA Deficiency

Demidowich, Andrew Paul,Kundu, Amartya,Reynolds, James C.,Celi, Francesco S. The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.3

A 42-year-old female with immunoglobulin A deficiency and recurrent sinopulmonary infections underwent thyroidectomy for papillary thyroid cancer (PTC). Follow-up $^{123}I$ scintigraphy demonstrated diffuse pulmonary uptake, suggesting metastatic disease. However, subsequent pathologic, biochemical and radiographic testing proved that she was in fact disease free, and the initial $^{123}I$ pulmonary uptake was identified as a false positive. Inflammatory conditions may rarely cause iodine uptake in non-thyroidal tissues due to local retention, organification, and/or immunologic utilization. To avoid exposing patients to unnecessary treatments, it is critical for clinicians to recognize that comorbid pulmonary conditions may mimic metastatic PTC on radioiodine scintigraphy.

Clearance of False-positive Antigen-Antibody Reactions of a Diagnostic Antigen Production in Escherichia coli with Human Sera

Noh, Kap-Soo,Kim, Jong-Wan,Ha, Suk-Hoon,Yoo, Wang-Don,Jeon, Weong-Joong,Kim, Hyun-Su The Korean Society for Biotechnology and Bioengine 1999 Biotechnology and Bioprocess Engineering Vol.4 No.1

Although many pharmaceutically useful proteins are produced in E. coli expression system, it is very are rare for the system to be used in the production of diagnostic antigen due to a major problem, i.e., false-positive reaction of e. coli host-derived proteins contaminating purified diagnostic antigen with human sera. The N (nucleocapsid) protein of Seoul virus causing haemorrhagic fever with renal syndrome (HFRS) was produced in E. coli BL21 (DE3), and used for the detection of N protein-specific antibodies in human sera. Using the N protein as a diagnostic antigen of HFRS, the false-positive reaction was cleared by merely mixing the test sera with the extract of E. coli host strain not harboring expression plasmid.

혈청 항기저막 항체검사에서 위양성을 보인 막증식성 사구체신염 1예

박경석 ( Kyoung Suk Park ),황선덕 ( Seun Duk Hwang ),전병수 ( Byung Soo Jeon ),최진이 ( Jin Yi Choi ),송지선 ( Ji Sun Song ),윤수영 ( Soo Young Yoon ),이상철 ( Sang Choel Lee ) 대한신장학회 2009 Kidney Research and Clinical Practice Vol.28 No.5

Anti-glomerular basement membrane (Anti-GBM) nephritis is an autoimmune disorder characterized by rapidly progressive crescentic glomerulonephritis (RPGN). The treatment of anti-GBM nephritis with plasmapheresis, steroids and immunosuppressant has improved outcomes. An early diagnosis is essential for the survival of patients and a recovery of renal function. The diagnosis of anti-GBM disease has been traditionally based on the demonstration of linear deposits of immunoglobulins along the glomerular basement membrane by immunofluorescence (IF) microscopy. However, a kidney biopsy cannot always be easily performed in such ill patients. Recent development of specific enzyme immunoassays for anti-GBM antibody in the serum has made possible a provisional diagnosis without a kidney biopsy. A 46-year-old male patient with hypertension and hepatitis B presented with generalized edema and general weakness. Laboratory findings were compatible with acute renal failure and nephritic syndrome with positive serum anti-GBM antibodies. After plasmapheresis with steroid pulse therapy, renal biopsy was performed and diagnosed as membranoproliferative glomerulonephritis (MPGN) with granular deposit of Ig G and C3. Follow-up antibody titers were negative. This case demonstrates the possibility of false-positive anti-GBM antibody in the serum. Therefore, enzyme immunoassay for anti-GBM antibody should be used only as a screening or follow-up test in patients that have been confirmed positive by IF microscopy.

Neuromonitoring in Cervical Spine Surgery: When Is a Signal Drop Clinically Significant?

Decruz Joshua,Kaliya-Perumal Arun-Kumar,Wong Kevin Ho-Yin,Kumar Dinesh Shree,Yang Eugene Weiren,Oh Jacob Yoong-Leong 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.3

Study Design: Retrospective cohort study. Purpose: To identify the clinical significance of different patterns of intraoperative neuromonitoring (IONM) signal alerts. Overview of Literature: IONM is a long-established valuable adjunct to complex spine surgeries. IONM for cervical spine surgery is in the form of somatosensory evoked potential (SSEP) and motor evoked potential (MEP). The efficacy of both modalities (individually or in combination) to detect clinically significant neurological compromise is constantly being debated and requires conclusive suggestions. Methods: Clinical and neuromonitoring data of 207 consecutive adult patients who underwent cervical spine surgeries at multiple surgical centers using bimodal IONM were analyzed. Signal changes were divided into three groups. Group 0 had transient signal changes in either MEPs or SSEPs, group 1 had sustained unimodal changes, and group 2 had sustained changes in both MEPs and SSEPs. The incidences of true neurological deficits in each group were recorded. Results: A total of 25% (52/207) had IONM signal alerts. Out of these signal drops, 96% (50/52) were considered to be false positives. Groups 0 and 1 had no incidence of neurological deficits, while group 2 had a 29% (2/7) rate of true neurological deficits. The sensitivities of both MEP and SSEP were 100%. SSEP had a specificity of 96.6%, while MEP had a lower specificity at 76.6%. C5 palsy rate was 6%, and there was no correlation with IONM signal alerts (p=0.73). Conclusions: This study shows that we can better predict its clinical significance by dividing IONM signal drops into three groups. A sustained, bimodal (MEP and SSEP) signal drop had the highest risk of true neurological deficits and warrants a high level of caution. There were no clear risk factors for false-positive alerts but there was a trend toward patients with cervical myelopathy.

Analysis of Major Factors Affecting False Positive Results in Neonatal Screening Test within 3 Days after Birth

( Tae Kyu Kim ),( Seung Hyun Lee ),( Seung Taek Yu ),( Yeon Kyun Oh ) 대한주산의학회 2019 Perinatology Vol.30 No.3

Objective: We examined the factors affecting the false positive results in the accidental neonatal screening test (NST) within 3 days after birth and tried to find out the most relevant factors. Methods: From January 2011 to December 2016, we reviewed the electronic medical records of 142 patients with a gestational age of 34 weeks or more who had false positives at the first NST. NST was performed by tandem mass spectrometry. We collected information on gestational age, birth weight, delivery method, Apgar score at the time of birth. Postnatal exam time, body weight, feeding volume and parenteral nutrition, antibiotics, and steroid administration were also investigated at the time of NST. Results: In the first NST, there were 102 cases of congenital adrenal hyperplasia, 27 cases of congenital hypothyroidism, nine cases of galactosemia and one case of homocystinuria. Gender, birth weight, and delivery method were statistically significant (P<0.05) at the time of birth using Pearson Chi-square method. There were significant differences in body weight, feeding volume, parenteral nutrition at the time of NST (P<0.05). In binary logistic regression analysis, the gender and the body weight seemed significant statistically. Conclusion: Male sex and weight were identified as major factors of the false positive results in the NST performed within 3 days after birth, but further studies seemed to be needed. In the case of patients with short admission period or insufficient perinatal information, the first NST after birth should be performed at the time of outpatient department or after precise information collection.

한국인에서 D-Dimer의 위양성과 관련된 인자와 검사의 정확도 향상을 위한 Cut-Off Value

홍만용 ( Man Yong Hong ),이창근 ( Chang Kun Lee ),유상용 ( Sang Yong Yoo ),신대희 ( Dae Hee Shin ),정상식 ( Sang Sig Cheong ),권장훈 ( Jang Hoon Kwon ),장우성 ( Woo Sung Jang ),유승진 ( Seung Jin Yoo ),오광훈 ( Kwang Hoon Oh ) 대한내과학회 2013 대한내과학회지 Vol.84 No.3

목적: 폐동맥 색전증과 심부 정맥 혈전증 이외에 D-dimer 검사의 양성 결과를 나타내는 여러 질환들이 보고되고 있으나, 현재까지 한국인에서 위양성을 유발하는 인자에 대해서는 명백하게 알려진 바가 없다. 따라서 한국인에서 위양성을 초래하는 인자들을 확인하고, 정확도를 향상시키기 위한 새로운 cut-off value를 제시하고자 한다. 방법: 2009년 1월부터 12월까지 본원에 방문한 환자 중 다양한 이유로 D-dimer 검사를 시행 받은 2,047명의 환자를 대상으로 분석하였고, 위양성을 유발하는 인자들을 확인하기 위해 오즈비와 95% 신뢰구간을 로지스틱 회귀분석을 이용하여 분석하였다. 새로운 cut-off value는 ROC curve를 이용하여 구하였다. 결과: 연령의 증가, 외상, 수술의 기왕력, 급성 감염, 결핵, 뇌혈관 질환, 악성종양, 만성 신부전, 급성 관동맥 증후군, 심부전, 호흡기 질환 등이 D-dimer 검사의 위양성을 유발하는 인자로 확인되었다. 또한 민감도와 특이도를 향상시키기 위해 ROC curve를 이용하여 구한 새로운 cut-off value는 0.68mg/L였다(65세 이하에서는 0.58 mg/L, 65세 이상에서는 0.77mg/L). 결론: 여러 인자들이 D-dimer 위양성과 관련이 있었으며, 임상에서 D-dimer 검사를 시행하고 임상에 적용할 때에는 이러한 인자들이 결과치에 영향을 줄 수 있음을 충분히 고려하여야겠다. Background/Aims: The D-dimer value is a simple blood test used to evaluate venous thromboembolism (VTE). However, due to its low specificity, another test is needed for a definite diagnosis, such as a radiographic test. We evaluate the factors associated with a false positive D-dimer test and propose a new cut-off value for detecting VTE more effectively in Koreans. Methods: This was a retrospective, observational study. From January 2009 to December 2009, 2,047 patients (988 men, 63 ± 15 years) had the D-dimer value checked to evaluate VTE. The main outcome of interest was a positive D-dimer test. Odds ratio and 95% confidence intervals were determined using logistic regression analysis. The new D-dimer cut-off was evaluated using receiver operating characteristics (ROC) curves. Results: The result was positive in 1,093 patients (53%), for a false positive percentage for VTE of 95% and a false negative percentage for VTE of 1%. Significant false positive predictors for a positive D-dimer were increasing age, trauma, postoperative, acute infection, tuberculosis, stroke, malignancy, chronic renal failure, acute coronary syndrome, heart failure, and lung disease. The discriminative value of the D-dimer test was assessed using ROC curve analysis. A D-dimer value of 0.68 mg/L on admission was the best cut-off value for predicting the development of VTE with a sensitivity of 95% and specificity of 57%. Conclusions: Many factors affect the D-dimer value and we must consider these factors before using the D-dimer value to evaluate VTE. A D-dimer value of 0.68 mg/L appears to be a good cut-off value for evaluating VTE more effectively in Koreans. (Korean J Med 2013;84:372-378)