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The incidence of peroneal tendon disorders in the population is unknown and they are usually overlooked. We report two cases of peroneus brevis injuries and a comprehensive literature review was performed. The first case was a 53-year-old man presented with persistent pain on the lateral aspect on the left ankle during the last four years and difficulty to bear weight during the last year. MRI showed longitudinal tear of peroneus brevis tendon and the patient underwent surgical treatment. The second case was a 46-year-old woman with persistent pain on the lateral aspect of the ankle with a history of a road traffic accident two years ago. Although MRI showed a peroneus brevis tendon tear, this was a false positive finding. Surgical treatment revealed no tear and symphysiolysis managed to relieve patient's symptoms. Even though MRI is the most effective diagnostic tool in depicting peroneal tendon injuries, there are false positive findings. In cases when symptoms persist, surgical exploration is indicated.

Scanning oncological patients with 18F-fluorodeoxyglucose (18F-FDG) for their disease staging, evaluation of treatment response, and monitoring/management has become a standard of care. The use of the radioactive fluorine in the FDG molecule helps establish cell/tissue lines high on glucose consumption and hence metabolically active. Abnormalities are detected on the scan as areas of increased uptake. However, these areas of increased (hot) uptakes do not necessarily translate into a pathological finding. A comprehensive knowledge of the uptakes of the tracer and the potential “pitfalls” that may be associated with them should be known and kept in mind during scan reading. One such pitfall is the “hot clot” or “pulmonary emboli,” and we report two such cases encountered at our setup and discuss their causes and how they should be identified and avoided.

This paper is a response to the study of Meyer-Rochow et al. (2020), who found a statistically significant increase of suicides during full moon among women in the region of Oulu, Finland. We argue that this may be a false-positive finding because of subgroups not specified a-priori and the many negative previous findings. Furthermore, we could not replicate the findings in a larger Austrian sample.

Author(s): Muhonen, Ethan G; Mahboubi, Hossein; Moshtaghi, Omid; Sahyouni, Ronald; Ghavami, Yaser; Maducdoc, Marlon; Lin, Harrison W; Djalilian, Hamid R | Abstract: ObjectivesTo investigate false-positive findings on non-echoplanar (non-EPI) diffusion-weighted magnetic resonance imaging (DWI) in patients under surveillance post-cholesteatoma surgery.Study design, setting, subjects, and methodsA retrospective review was performed on patients diagnosed with cholesteatoma who underwent surgical resection and were then followed by serial non-EPI DWI using half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence. All patients had at least two annual follow-up imaging studies.ResultsFalse-positive findings were identified in four patients. The size of the suspected lesions was 4 to 12 mm. Otoendoscopy was used during all primary cases and Argon laser was used in one case. In all cases, the entire cholesteatoma was removed, and no residual disease was detected at the end of the procedures. One patient underwent revision surgery but only cartilage graft was found in the area of concern. All patients had stable or resolved hyperintense areas in the subsequent HASTE sequences.ConclusionFalse positive findings can occur with non-EPI DWI MRI and patients need to be counseled accordingly before revision surgery. Decreasing intensity and dimension of a suspected lesion and a positive finding in an area other than the location of the initial cholesteatoma may favor a false positive. If a false positive finding is suspected when the surgeon is confident of complete resection of the cholesteatoma, an MRI can be repeated in 6 to 12 months to assess changes in the dimension and intensity of the area of concern. Cartilage grafts may cause restricted diffusion on DWI sequences.

Background The F-18 fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) has become an established diagnostic imaging for malignancy. However, there are other diseases that can also be identified with FDG, some of them are infections such as tuberculosis. Case presentation In this case report, two patients showed multiple hypermetabolic tuberculosis lesions on FDG PET/CT, with one of the patients having history of malignancy. The objective of the present case report is to emphasize the need to use other differential diagnosis techniques for tuberculosis especially in tuberculosis-endemic countries when interpreting FDG PET/CT. Conclusion By analyzing diagnostic imaging alone, there is a high chance of misinterpreting asymptomatic tuberculosis patient as having malignancy. Therefore, there is need for correlation with clinical data as well as other imaging modalities and PET/CT with more specific tracer in order to differentiate malignancy from benign disease such as tuberculosis.

A 73-year-old man with history of prostatic adenocarcinoma radical prostatectomy underwent 99mTc-MDP whole-body bone scan and subsequent 68Ga-labeled prostate-specific membrane antigen (PSMA) ligand PET/CT for restaging due to a gradual rise of prostate-specific antigen levels. Whole-body bone scan showed two focal zones of slightly increased uptake in the right fronto-parietal and temporal bones. 68Ga-PSMA PET/CT scan showed local recurrence in the prostatic bed and two foci of slightly increased uptake in the right temporal and fronto-parietal lobes. A brain CT scan, with IV contrast confirmed that foci of increased uptake in the temporal and parietal lobes were consistent with typical meningioma.

Primary Epstein–Barr virus (EBV) infection is common in childhood, and dual positivity of serum EBV IgM and cytomegalovirus (CMV) IgM antibodies occur in some cases. This study aimed to evaluate the cause of EBV and CMV IgM dual positivity to determine whether it represents a false-positive finding or a true coinfection. A total of 494 children diagnosed with primary EBV infection, manifesting as infectious mononucleosis, were recruited. The diagnosis was based on positive EBV viral capsid antigen (VCA) IgM antibodies, and serum CMV IgM antibodies and liver enzymes were also evaluated in 149 subjects. Of 149 children with primary EBV infection, 40 (26.8%) had serum EBV VCA IgM and CMV IgM dual positivity. However, true CMV infection was confirmed only in 1 child of 40 (2.5%) who was positive for both serum CMV Ag and urine CMV polymerase chain reaction (PCR) and negative for serum CMV IgG antibody. Among the children with primary EBV infection, the rate of dual positivity was higher in infants and lower in adolescents (P = .013). Liver enzymes were more significantly elevated in children with dual positivity than in those with negative results for CMV IgM antibodies (P = .026), which correlated with the serum EBV and CMV IgM titers. Serum EBV and CMV IgM dual positivity are more prevalent in children with primary EBV infection than what was previously reported. Our results indicate that serum EBV and CMV IgM dual positivity represents a false-positive finding, as opposed to an actual CMV coinfection, possibly due to antigenic cross-reactivity.

While mounting evidence indicates that a phylogenetically diverse group of animals detect Earth-strength magnetic fields, a magnetoreceptor has not been identified in any animal. One possible reason that identifying a magnetoreceptor has proven challenging is that, like many research fields, magnetoreception research lacks extensive independent replication. Independent replication is important because a subset of studies undoubtedly contain false positive results and without replication it is difficult to determine if the outcome of an experiment is a false positive. However, we report here a reanalysis of a well-cited paper on honeybee magnetoreception demonstrating that the original paper represented a false positive finding caused by a misunderstanding of probability. We also point out how good experimental design practices could have revealed the error prior to publication. Hopefully, this reanalysis will serve as a reminder of the importance of good experimental design in order to reduce the likelihood of publishing false positive results.

We present two cases of cholesteatoma and one false positive finding in non-EP DW MRI in order to highlight the differential diagnosis in imaging and emphasize the need to discuss the findings with the otologic surgeon. The first case demonstrates different MRI signal patterns encountered in a patient with cholesteatoma. The second report is a rare case of supralabyrinthine cholesteatoma with atypical clinical presentation. The third case presents a rare but important false positive finding in non-EP DW MRI. Clinical and imaging findings are discussed taking into account the current literature.

An outbreak of dengue fever occurred in Japan in August 2014. We herein report the case of a 63-year-old man who presented with a persistent fever in September 2014. Acute parvovirus B19 infection led to a false positive finding of dengue fever on a rapid diagnostic test (Panbio Dengue Duo Cassette(TM)). To the best of our knowledge, there are no previous reports of a false positive result for dengue IgM with the dengue rapid diagnostic test. We believe that epidemiological information on the prevalence of parvovirus B19 is useful for guiding the interpretation of a positive result with the dengue rapid diagnostic test.

Sclerosing Angiomatoid Nodular Transformation (SANT) is a rare benign vascular tumor of spleen. It consists of multiple angiomatoid nodules surrounded by dense fibrous tissue that often coalesces centrally to form a scar, which is considered to be a characteristic feature. These are usually asymptomatic and incidentally detected on imaging for other underlying pathology. SANTs can be 18F-Fluorodeoxyglucose (18F-FDG) avid on positron emission tomography-computed tomography (PET-CT) and thus can lead to false positive finding in oncological patients.

症例は58歳，男性．胃上部2型進行癌に対し胃全摘術，D2リンパ節郭清，脾・膵尾部合併切除術を行った．病理組織学的に低分化型腺癌で，深達度SS，2群リンパ節に転移を認め，T2，N2，H0，P0，CY0，M0，Stage IIIB，根治度Bであった．5年前より狭心症と糖尿病のため内服治療中であったがいずれもコントロール良好であった．術前の腫瘍マーカーCEA値は3.3ng/mLと正常範囲内であった．術後2カ月目よりCEA値の増加および空腹時血糖値の上昇を認めた．術後4カ月目にはCEA 12.0ng/mL，空腹時血糖232mg/dL，HbA1c 8.6となった．画像評価を行うも明らかな再発病変を同定できなかったため，無治療のまま厳重に経過観察をすることとした．同時に食事・内服療法による糖尿病の治療も開始した．以後血糖コントロールの安定とともに腫瘍マーカー値は漸減していった．術後4年3カ月の現在まで無再発生存中である．

Bronchial anthracofibrosis characterized by bronchostenosis associated with anthracotic pigmentation in bronchoscopic finding without a relevant history of pneumoconiosis or smoking has been recently described as a clinical entity. Radiologic finding of bronchial obstructive lesion and mediastinal lymph nodes in bronchial anthracofibrosis can be mimicking cancer. However, the metabolic characteristics of bronchial anthracofibrosis have hardly been reported. Here, we report a case of bronchial anthracofibrosis which showing hypermetabolism on F-18 FDG PET.

Purpose: To compare the performance of virtual and conventional colonoscopy for the detection of colorectal polyps using a multislice spiral CT scanner (MSCT). Materials and Methods: 48 patients (20 women, 28 men, mean age 61.5 5 years) with clinical indication for conventional colonoscopy were prospectively studied using a MSCT (Somatom Volume Zoom, Siemens, Forchheim). Examination was performed after standard oral preparation for colonoscopy and colonic distension with room air and i.v. butylscopolamin. Images were obtained in prone and supine position using a detector configuration of 4 × 1 mm, a table feed of 5 mm/rotation at 140 mAs and 120 kV. Slice thickness and reconstruction increment were 3 and 1.5 mm, respectively. CT data were assessed by two blinded radiologists on a Vitrea workstation (Vital Images, USA) using a software with multiplanar and volume-rendering capabilities. Results: 33 patients had normal findings on conventional colonoscopy. In 15 patients a total of 30 polyps and one carcinoma with stenosis were identified. MSCT-colonography identified the carcinoma and 23 polyps (77%). 3 of 3 polyps were 10 mm or more (100%), 6 of 7 were 5.1 to 9.9 mm (86%) and 14 of 20 were 5 mm or smaller (70%). There were 13 false positive findings for polyps (10 lesions < 6 mm in 5 patients) and no false positive finding of carcinoma. Conclusions: MSCT colonography allows accurate detection of polyps larger than 10 mm. Compared to published results of single-slice CT, multislice CT colonography increases the rate of detection of small colorectal polyps in particular. However, false positive results still remain a problem.

Avid functional (18)F-FDG uptake of skeletal muscle is a known false positive finding of PET-CT study especially after involuntary muscle exercise just prior to the study. We describe the case of a 50-year-old man in whom the finding of avid (18)F-FDG uptake of pectoralis major muscle was encountered during investigation of metastatic melanoma.

Methods 24 primary and pre-treated patients diagnosed with multiple myeloma according to the International Myeloma Working Group criteria were examined by F-FDG PET/CT and whole-body MRI including DWI (b= 0, and b= 800 s/mm). F-FDG PET/MRI was used to achieve correct matching of findings in the corresponding PET/ CT study. Suspicious lesions were defined by the imaging gold-standard of nonenhanced T1-w/T2-wMRI and low-dose CT.

False-positive findings are commonly seen in positron emission tomography computed tomography imaging. One of the most common false positive finding is uptake of fluorodeoxyglucose in brown adipose tissue. Herein, we report two cases with incidentally detected hibernomas-a brown fat containing tumor with metabolic activity.

False positive findings are a common problem in whole genome association studies. In this commentary we show that nothing is gained by randomly splitting a data sample to two equal sized subsets, where the first data subset is used for explorative purposes and the other sub set is used to confirm the findings in the first subset. We compare the random splitting procedure to using the full data sample for analysis, by using a Bayesian perspective with consideration taken to prior probability of a false positive finding.

Identification of genetic variants affecting complex traits such as obesity is confounded by many types of bias, especially when effect sizes are small. Given our findings of a positive association between rs7566605 and body mass index in four out of five separate samples, a false positive finding cannot be ruled out with certainty but seems unlikely. Meta-analyses of multiple large studies will help refine the estimate of the effects of rs7566605 on body mass index.

Many chemicals shown to be teratogenic in laboratory animals are not known to be teratogenic in humans. However, it remains to be determined if the unresponsiveness of humans is due to lessened sensitivity, to generally subteratogenic exposure levels, or to the lack of an appropriate means of identifying human teratogens. On the other hand, with the exception of the coumarin anticoagulant drugs, those agents well accepted as human teratogens have been shown to be teratogenic in one or more laboratory species. Yet, no single species has clearly distinguished itself as being more advantageous in the detection of human teratogens over any other. Among the species used for testing, the rat and mouse most successfully model the human reaction, but the rabbit is less likely than other species to give a false positive finding. Among species less commonly used for testing, primates offered a higher level of predicability than others. Regarding concordance of target malformations, the mouse and rat produced the greatest number of concordant defects, but they also were responsible for the most noncorcordant responses as well. Since no other species is clearly more predictive of the human response, it is concluded that safety decisions should be based on all reproductive and developmental toxicity data in light of the agent's known pharmacokinetic, metabolic and toxicologic parameters.

1. Residual barium in the bowel, when superimposed over the liver, can produce localized areas of decreased uptake on a scan and thereby a false positive finding. This was detected clinically and confirmed by experimental means.2. A scout roentgenogram of the abdomen is recommended immediately prior to the scanning of abdominal organs.