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131I scan plays a crucial role in the management of patients with differentiated thyroid cancer for the evaluation of remnant thyroid tissue, residual/recurrent metastatic disease, posttherapy tracer distribution, and response assessment to high-dose 131I therapy. Different causes secondary to physiological, pathological, and anatomical variations have been described for false-positive findings in the whole-body planar images. This case report of a patient of differentiated thyroid cancer with undocumented trauma to the left knee region a day before receiving the high-dose radioiodine therapy showed an interesting image finding of tracer uptake at unusual site in the posttherapy whole-body 131I scan.

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.

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.

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.

Xanthogranulomatous inflammation in the spinal epidural space is extremely rare. We report a case of a 62-year-old man with a xanthogranulomatous inflammation in the spinal epidural space mistaken for lymphoma because of its avid F FDG uptake on PET/CT. This case emphasizes the need for caution when evaluating a spinal epidural mass using F FDG PET/CT as xanthogranulomatous inflammation can induce a false-positive reading on F-FDG PET/CT.

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.

The presence of illegal dyes such as the Sudan reds in spices is a well-recognised problem, and numerous methods of analysis have been described for their determination. However, some spice-derived matrices present particular problems. Oleoresins, complex extracts of spices containing phenolic natural pigments and terpene-like lipids, are used in the formulation of oriental sauces, pickles and processed spiced meals and hence likely to penetrate far into the food chain. Described herein is a case in which a false positive finding of one of the less commonly used illegal dyes in an oleoresin had the potential to trigger a costly food recall. Rapid resolution of the false positive by liquid chromatography–tandem mass spectrometry (LC-MS/MS) came at the cost of subsequent decontamination of the instrument, incurring significant downtime. The analytical difficulties posed by the presence of a surfactant to improve oleoresin dispersive properties with other foods are discussed. We conclude that as LC-UV methods cannot deal with the possible matrix interferences, they must not be used for the analyses of illegal dyes in spice oleoresins. A combination of gel permeation chromatography with liquid–liquid and solid-phase cleanup is described that enables facile deployment of LC-MS/MS to an oleoresin–surfactant matrix for the forensically robust determination of dimethyl yellow at concentrations below the current “action limit” for illegal dyes of 500 μg kg−1.

By applying the logic of genetics and available knowledge on allele frequencies it is possible to put forward hypotheses on genes underlying IQ by data mining. At the present state of knowledge the probability of a false positive finding that C2orf16 rs1919128 is the major gene of IQ is about 0.000005

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．

Objective Fluorodeoxyglucose (FDG) positron emission tomography (PET) is increasingly used to support a diagnosis of Alzheimer's disease. The aim of the present study was to evaluate a new expert system (PALZ) for the fully automated analysis of FDG PET images for diagnosis of the disease. Methods The PALZ tool is based on the detection of the typical disease pattern in FDG PET images. Its potential for this task was evaluated in 22 consecutive patients with suspected Alzheimer's disease who had been graded as positive for the pattern by an experienced reader (visual analysis supported by statistical parametric mapping (SPM)), and in 18 controls. Dependence on scanner performance was assessed by variation of the spatial resolution of the PET images. Results All the Alzheimer's disease subjects were classified as pattern-positive by the PALZ tool. Fifteen controls were classified as normal. Sensitivity and specificity for differentiation of the patients with suspected Alzheimer's disease from the controls were 100% and 83%, respectively. The false positive finding in three controls most likely was caused by differences in attenuation correction between the normal data base of the PALZ tool (cold transmission scan) and the local data sets (hot transmission scan). There was only mild dependence on spatial resolution. Conclusions The results of the present study suggest that the PALZ tool provides similar performance for the detection of the typical Alzheimer's disease pattern in FDG PET images as an experienced reader supported by SPM. The PALZ tool is fully automated, easy to use, and insensitive to the spatial resolution of the PET scanner used. Therefore, it has the potential for widespread clinical use.

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.

WEB This is a Web exclusive article. ET with 18F-FDG has been successfully used for the diagnosis, management, and follow-up of many malignant tumors. PET is particularly useful for staging of head and neck tumors and for detecting recurrence [1]. Its utility in other settings, however, such as detection of non–squamous cell cancer of the head and neck and differentiating benign salivary gland tumors from malignant ones, is limited [2, 3]. This lack of usefulness may partly be explained by the poor anatomic localization of PET combined with variable physiologic uptake of FDG in the head and neck. These factors decrease the specificity of PET for head and neck cancer and thus increase the rate of false-positive findings. Combined PET/CT scanners, which fuse the functional data of PET with the anatomic data of CT, have shown promise in the evaluation of cancer of the head and neck [4]. Non–squamous cell cancer of the head and neck, particularly salivary gland tumors, however, have not been studied extensively with either PET or combined PET/CT. In cases that have been studied, the variable uptake from salivary gland tumors often causes false-negative results [4–6]. In addition, some benign tumors of the salivary glands, particularly Warthin’s tumor, show focal FDG uptake leading to false-positive results [2]. These false-positive findings reduce the utility of PET in differentiating benign salivary gland tumors from malignant tumors. We report a case of a benign parotid oncocytoma that had marked FDG avidity on PET/CT.

Laparoscopy and magnetic resonance imaging (MRI) are competetive tools in the diagnostic of non-palpable testis. Advantages and disadvantages of this methods will be demonstrate. 29 boys investigated for this indication with MRI. In case MRI failed to locate the testis laparoscopy was performed with a new miniaturized set of pediatric instruments (1.9 mm optic). The aim of laparoscopy was the identification of the spermatic duct and vessels and their topographic relation to the internal inguinal ring. All findings were verified by open surgical procedures. MRI revealed 10 inguinal and 7 abdominal testis. There was no false positive finding. In 12 boys MRI showed no testis. 4 cases were correct negative, 8 cases were false negative (32 %). In these 8 MRI-negative patients laparoscopy revealed 7 inguinal and 1 abdominal testis. The optical quality of the mini-telescope was sufficient for a 100 % correct diagnosis. Laparoscopy related complications did not occur. Laparoscopy proved to be a powerful low risk diagnostic method in non- palpable testis with high senitivity and specifity (100 % correct positive, 0 % false negative). Therefore lapraroscopy is recommended as primary diagnostic access for this indication. In the same anesthesia a optimal therapy is possible. Nevertheless a positive MRI-finding locates the testis reliably, whereas a negative finding always needs further exploration because testis might have been missed.

Kimura disease is a chronic inflammatory disorder that occurs mainly in Asians. We present a patient with pulmonary Kimura disease assessed by whole-body 18F-FDG PET/CT examination and proved by pathologic findings. Chest x-ray detected left pulmonary hilum enlargement in a 49-year-old Chinese man. CT showed a soft tissue mass with punctate calcifications in the left pulmonary hilum, which obviously and homogeneously accumulated tracer on FDG PET. Histopathology findings showed characteristic of Kimura disease. Kimura disease should be included in the differential diagnosis of a pulmonary hilar tumor.

Testing for drugs of abuse in urine is usually performed in two steps; after initial screening positive findings are confirmed with specific chromatographic techniques. The use of different methods with different cut-off levels, may lead to variable results in a test sample containing a drug. Sixty-eight Swedish laboratories were enrolled in an external quality study and received three control samples. The laboratories were instructed to perform only in-house tests for amphetamines, benzodiazepines, cannabinoids, cocaine and opiates. Nineteen out of the 68 laboratories reported fully correct results. Thirty reported one o more false positive drug findings. One laboratory performing confirmation with gas chromatography--mass spectrometry reported a false positive finding of amphetamines in the sample containing ephedrine. Since testing for drugs of abuse in urine is a delicate matter, with both medical and legal implications, such testing should be performed with a zero rate of false positive results. Routine use of specific methods for confirmation should be used since performance of these laboratories was better in this study. It is concluded that there is a need to continuously measure the level of quality of laboratories by a program for external quality control.

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.

We report herein two cases of suture granuloma showing focal intense 2-deoxy-2-[18F]fluoro- d -glucose (FDG)-uptake in positron emission tomography (PET). Follow-up FDG-PET after surgical intervention for head and neck cancer revealed lesions with high FDG-uptake, which were highly suspected of being a recurrent tumor. The lesions were subjected to excisional biopsy for definitive diagnosis. Histopathological examination proved them to be suture granulomas caused by non-absorbable silk sutures. It should be emphasized that suture granulomas can show false-positive findings on FDG-PET, thus requiring differential diagnosis from recurrent tumors.

Absence seizures are characterized by sudden loss of consciousness and interruption of ongoing motor activities for a brief period of time lasting few to several seconds and up to half a minute. Due to their brevity and subtle clinical manifestations absence seizures are easily missed by inexperienced observers. Accurate evaluation of their high frequency of recurrence can be a challenge even for experienced observers. We present a novel method for detecting and analyzing absence seizures acquired from electroencephalogram (EEG) recordings in patients with absence seizures. Six patients were included in this study, two seizure free, of a total recording time of 26 hours, and four experiencing over 100 seizures within 14.5 hours of total recordings. Our algorithm detected only one false positive finding in the first seizure free patients and 148 of 186 continuous uninterrupted 3Hz spike and wave discharge (SWD) epochs in the rest of the patients. Out of the total 38 missed SWD epochs 28 were

The value of colour Doppler sonography in the diagnosis of renal artery stenosis has been studied retrospectively. 17 patients were examined (34 main renal arteries and 7 accessory renal arteries; ages 37 to 84 years; 7 males and 10 females). We studied 1) ability to study the main renal arteries, 2) visibility of accessory renal arteries and 3) the sensitivity and specificity of colour Doppler sonography for the diagnosis of renal artery stenosis. The results were compared with intraarterial angiography. Demonstration of the main renal arteries with colour Doppler sonography was possible in 23 of the 34 vessels. Not a single of the 7 accessory renal arteries was demonstrated by colour Doppler sonography. Of 8 angiographically demonstrated stenoses (more than 50% narrowing) 2 were missed by colour Doppler sonography. One stenosis was correctly diagnosed and 5 were incorrectly evaluated by sonography. 16 out of 18 angiographically normal main renal arteries were correctly evaluated by colour Doppler sonography but 2 showed a false positive finding. This results in a sensitivity of 17% and a specificity of 89% per kidney. Colour Doppler sonography cannot be recommended as a screening method for renal artery stenosis in view of its limited accuracy.

Background: Emergency physicians commonly perform Focused Assessment with Sonography for Trauma (FAST) examinations to evaluate for free intraperitoneal fluid. Many ultrasound findings can be misinterpreted as free fluid, resulting in false-positive FAST examinations. Objectives: To describe a previously unreported ultrasound finding that can be misinterpreted as free intraperitoneal fluid. Case Report: A 32-year-old man was stabbed in the left upper abdomen. A FAST examination was performed and a right perinephric fat pad was interpreted as showing free fluid in Morison's pouch. After transfer to a trauma center, a repeat FAST examination revealed no signs of intraperitoneal free fluid. Wound exploration showed no signs of penetration into the peritoneal cavity. Conclusions: When performing a FAST examination, a wedge-shaped hypoechoic area in Morison's pouch that is bounded on both sides by echogenic lines (the “FAST Double-Line Sign”) is likely to represent perinephric fat and may result in a false-positive FAST examination.

Purpose: To compare the influence of visual and acoustical CAD markers on radiologist’s performance with regard to suggestive and distractive effects. Materials and methods: Ten radiologists analyzed 150 pictures of ches t CT slices. Every picture contained a visual CAD marker. 100 pictures showed one nodule: CAD marker marked this in 50 cases and in 50 cases a false positive finding (f.p.). The other 50 cases showed no nodule but an f.p. marker. After 3 years same images were presented to thirteen radiologists with only a sound as CAD marker. 55 of 150 images were marked, 30 true positive and 25 f.p. Sensitivity and f.p. rate were calculated for both marker ty pes. Significance between sens itivities and f.p. rates were calculated by multiple-ana lysis-of-variance (MANOVA). Results: Without CAD mean sensitivity resp. f.p. were 57.7% /.13 . In case of correct optical resp. acoustical marker sensitivity increased to 75.6% resp. 63.1%. For incorrect se t marker mean f.p. rate increased to .31 resp. .24. MANOVA showed that marker’s correctness highly significan tly influenced sensitivity (p

Autofluorescence bronchoscopy (AFB) has been utilized over the past decade, proving to be a powerful tool for the detection and localization of premalignant and malignant lesions of the airways. Autofluorescence bronchoscopy is, however, characterized by low specificity and a high rate of false positive findings (FPFs). The majority of FPFs are due to inflammations, as they often fluoresce at the same wavelengths with cancer. According to several clinical trials, the percentage of the FPFs is about 30%. In this paper we present an intelligent computing system for the classification of suspicious areas of the bronchial mucosa, in order to decrease the rate of FPFs, to increase the specificity and sensitivity of AFB and enhance the overall diagnostic value of the AFB method.

The FAST exam has become the current standard for free intraperitoneal fluid determination in most emergency departments. Knowledge of false negative and false positive findings is imperative to improve accuracy. We detail a case in which an important false positive findings previously not discussed in the medical literature was noted. The ability of the physician to recognize the "gastric fluid" sign and make the adjustments accordingly could improve the specificity of the FAST exam, preventing non-therapeutic laparotomies.

Purpose: The efficiency of the detection of pulmonary nodules by a radiologist with the help of CAD is influenced by the user interface of the system. Marker with a visually dominant appearance may distract the radiologist from other parts of the screen. Purpose was to analyse the influence of different CAD markers on radiologist's performance. Materials and methods: 10 radiologists analysed 150 pictures of chest CT slices. Every picture contained a CAD marker; five different types of markers were used - each respectively on 30 pictures (1: thick walled square, 2: thin walled circle, 3: small arrow, 4: pixel sized point on nodule, 5: very subtle change of colour). One hundred images contained one nodule: CAD markers marked this finding in 50 cases; in 50 cases a false positive finding was marked instead. The remaining 50 images contained no nodule but a marker of a false positive finding. The radiologists had to decide for each image if there was a nodule visible and either click on the nodule or on a button "no finding". Sensitivity and specificity were calculated for each marker type. Results: Mean sensitivity was 59%, 62%, 64%, 65% and 64% for marker 1 to 5, respectively. Specificity was 50%, 51%, 64%, 45% and 67%. In the cases with false positive findings sensitivity for detection of the unmarked nodule was 41%, 58%, 59%, 49% and 54%. New work to be presented: The study shows that the marker type influences radiologist's sensitivity and distraction from other findings. Conclusion: Of the tested markers a small arrow was most efficient for the presentation of the results to the radiologist.

The purpose of the presented study was to determine the impact of two different CAD systems used as concur-rent reader for detection of actionable nodules (>4 mm) on the interpretation of chest CT scans during routine reporting. Fifty consecutive MDCT scans (1 mm or 1.25 mm slice thickness, 0.8 mm reconstruction increment) were se-lected from clinical routine. All cases were read by a resident and a staff radiologist, and a written report was available in the radiology information system (RIS). The RIS report mentioned at least one actionable pulmonary nodule in 18 cases (50%) and did not report any pulmonary nodule in the remaining 32 cases. Two different recent CAD systems were independently applied to the 50 CT scans as concurrent reader with two radiologists: Siemens LungCare NEV and MEDIAN CAD-Lung. Two radiologists independently reviewed the CAD results and determined if a CAD result was a true positive or a false positive finding. Patients were classified into two groups: in group A if at least one actionable nodule was detected and in group B if no actionable nodules were found. The effect of CAD on routine reporting was simulated as set union of the findings of routine reporting and CAD thus applying CAD as concurrent reader. According to the RIS report group A (patients with at least one actionable nodule) contained 18 cases (36% of all 50 cases), and group B contained 32 cases. Application of a CAD system as concurrent reader resulted in detec-tion of additional CT scans with actionable nodules and reclassification into group A in 16 resp. 18 cases (radi-ologist 1 resp. radiologist 2) with Siemens NEV and in 19 resp. 18 cases with MEDIAN CAD-Lung. In seven cases MEDIAN CAD-Lung and in four cases Siemens NEV reclassified a case into group A while the other CAD system missed the relevant finding. Sensitivity on a nodule (>4 mm) base was .45 for Siemens NEV and .55 for MEDIAN CAD-Lung; the difference was not yet significant (p=.077). In our study use of CAD as second reader in routine reporting doubled the percentage of patients with actionable nodules larger than 4 mm.

This case report describes a patient who presented to the Emergency Department (ED) after a high-speed motor vehicle crash (MVC), whose initial ultrasound examination was interpreted as being positive for fluid in Morison’s pouch. Subsequent ultrasound examinations and computed tomography scans further delineated this finding to be fluid-filled bowel juxtaposed between the liver and right kidney. With greater implementation of ED ultrasound, it is important to identify entities that cause false-positive and false-negative examinations.

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.

PET/CT is a widely accepted imaging modality in the diagnosis and staging of lymphoma because of the increased FDG uptake commonly detected in malignant lesions. However, various causes of false-positive FDG localization have been described, including in nonmalignant lymph nodes. We report a patient with a history of Hodgkin lymphoma who presented with bilateral axillary lymphadenopathy, which was intensely FDG-avid on PET/CT imaging. Biopsy of lymph nodes from both axillae revealed benign follicular hyperplasia. Follicular hyperplasia is a potential false-positive finding on PET/CT imaging, and obtaining pathologic confirmation of malignancy should be considered before treatment.

It has been noticed that the postmortem liver samples gives a positive result for amphetamines, although it is proved that the person has not previously consumed amphetamines. Postmortem liver samples are of great importance since they contain many valuable specimens in higher concentration then in some other biological samples. It was observed that liver tissue from persons found several days after death occur contains amphetamines. Purpose - The purpose of this study is to determine conditions that are responsible for amphetamine false positive finding in postmortem liver samples. Methods- Postmortem liver samples, which should be toxicologically processed, and the previous test gave negative amphetamine findings, are divided into several samples with identical weight and were subjected to the influence of different temperature in different time period. At various time intervals samples are being analyzed and determent qualitatively and quantitative by gas chromatography- mass spectrometry technique (GC/MS). Results - Liver samples with amphetamine negative findings, gave positive results after few days at temperature of 32, 5 degree Celsius. It was noted that the alcohol concentration has an effect on amphetamine occurrence.

Nearly 13 years ago inflammation imaging using labeled white blood cells (WBCs) has been introduced in clinical nuclear medicine.

Varicocele is the most frequent operable cause of male infertility. It is often difficult to diagnose small lesions merely by clinical examination. The fact that a measurable rise of scrotal temperature occurs in a certain number of infertile patients has helped to extend thermography also to the detection of such cases (Comhaire et al., 1976; Zorgniotti and MacLeod, 1973).

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.

Somatostatin receptor scintigraphy with In-111 octreotide has shown excellent accuracy in many neuroendocrine tumors, including carcinoid. Substantial gallbladder activity may be present on early images; however, the administration of a fatty meal and/or the effect of time generally results in littl

CT was carried out in 50 patients with clinical suspicion of hyperparathyroidism, in order to localise the adenoma. In 45 patients, the diagnosis was confirmed at operation and adenomas or hyperplastic glands were removed. In the remaining five patients the diagnosis was not confirmed at operation, nor by the subsequent clinical course. On four occasions, CT correctly turned out to be negative and in one patient a false positive finding was obtained. Amongst the 45 patients, a total of 59 enlarged glands (adenomas or hyperplastic glands) were found at operation and removed. Pre-operative CT was positive and correct in 78% and negative and incorrect in 22%. Of eight adenomas in the mediastinum, seven could be recognised pre-operatively. Previous operations on the neck did not reduce diagnostic accuracy. The techniques and results are described and discussed.

Between 1965 and 1968, 6500 lymphograms were performed at the University of Gottingen. Amongst these, there were 412 patients with malignant testicular tumours. In 81 patients the results of lymphography could be checked histologically. There was agreement between the lymphographic and histological findings in 65 patients (80.3%), sensitivity of 98.1% (51 out of 52) and specificity of 48.3% (14 out of 29). In 50 patients CT was performed in addition. The findings agreed in 31 cases; in eight patients lymphangiography resulted in a false positive finding and CT was incorrect in 12 patients. In all patients with proven retroperitoneal metastases, one or the other method produced a correct diagnosis.

The specificity of radioimmunoassay of aflatoxin B1 was tested. Relative cross-reactivity of used antiserum with aflatoxins B1, B2, G1, G2 and M1 was found to be 100%, 24%, 44.2%, 10.3%, and 1.4%, respectively. The interference of coumarin, albumins, steroids and ethylvanilin was estimated also in radioimmunoassay of aflatoxin B1. Thus these compounds may cause a false positive finding of aflatoxin B1.

Selective venous sampling for parathormone estimations has become an important method in the diagnosis of primary hyperparathyroidism and, together with thyroid phlebography, is an accurate means for localising hormone active parathyroid tissue. Thirty-three patients were examined by this technique and in 25 of these an exploration was carried out subsequently. Twenty-one had primary hyperparathyroidism. In one case hormone analysis lead to a false positive finding. In 18 of these 21 patients, the hormone-active parathyroid tissue was correctly localised. Phlebography showed evidence of an adenoma in five patients, but is of most use for localising the source of the hormone.

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.

A consecutive series of 301 ultrasonically guided fine needle aspiration biopsies of renal masses was reviewed. The retrieval rate was 95 per cent and a correct cytological diagnosis was established in 82 per cent of the cases. There were 14 false positive aspirates, for a predictive value of a malignant aspirate of only 93 per cent. All false positive results were misinterpreted as relatively well differentiated adenocarcinoma. We conclude that renal fine needle aspiration biopsy may add information but the risk of a false positive finding must always be considered.