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Purpose Vitamin D (VitD) is a pleiotropic hormone with effects on a multitude of systems and metabolic pathways. Consequently, the relevance of a sufficiently high VitD serum level becomes self-evident. Methods A rapid immunofluorescence assay designed for the point-of-care measurement of serum VitD3 solely was tested. Inter- and intra-assay validation, double testing and result comparison with a standardized laboratory method were performed. Results An overall linear correlation of r = 0.89 (Pearson, 95% CI 0.88–0.92, p r = 0.91, 95% CI 0.86–0.94, p r = 0.86, 0.82–0.89, p Conclusion This novel, innovative, and controlled study indicates that the evaluated rapid point of care VitD assay is reliable, accurate, and suited for clinical practice.

Objectives To quantitatively evaluate the impact of virtual monochromatic images (VMI) on reduced-iodine-dose dual-energy coronary computed tomography angiography (CCTA) in terms of coronary lumen segmentation in vitro, and secondly to assess the image quality in vivo, compared with conventional CT obtained with regular iodine dose. Materials and methods A phantom simulating regular and reduced iodine injection was used to determine the accuracy and precision of lumen area segmentation for various VMI energy levels. We retrospectively included 203 patients from December 2017 to August 2018 (mean age, 51.7 ± 16.8 years) who underwent CCTA using either standard (group A, n = 103) or reduced (group B, n = 100) iodine doses. Conventional images (group A) were qualitatively and quantitatively compared with 55-keV VMI (group B). We recorded the location of venous catheters. Results In vitro, VMI outperformed conventional CT, with a segmentation accuracy of 0.998 vs. 1.684 mm2, respectively (p < 0.001), and a precision of 0.982 vs. 1.229 mm2, respectively (p < 0.001), in simulated overweight adult subjects. In vivo, the rate of diagnostic CCTA in groups A and B was 88.4% (n = 91/103) vs. 89% (n = 89/100), respectively, and noninferiority of protocol B was inferred. Contrast-to-noise ratios (CNR) of lumen versus fat and muscle were higher in group B (p < 0.001) and comparable for lumen versus calcium (p = 0.423). Venous catheters were more often placed on the forearm or hand in group B (p < 0.001). Conclusion In vitro, low-keV VMI improve vessel area segmentation. In vivo, low-keV VMI allows for a 40% iodine dose and injection rate reduction while maintaining diagnostic image quality and improves the CNR between lumen versus fat and muscle. Key Points • Dual-energy coronary CT angiography is becoming increasingly available and might help improve patient management. • Compared with regular-iodine-dose coronary CT angiography, reduced-iodine-dose dual-energy CT with low-keV monochromatic image reconstructions performed better in phantom-based vessel cross-sectional segmentation and proved to be noninferior in vivo. • Patients receiving reduced-iodine-dose dual-energy coronary CT angiography often had the venous catheter placed on the forearm or wrist without compromising image quality.

Objectives Due to the partly strongly differing results in the literature, the aim of the present study was to investigate a possible deformation of the mandible during mouth opening using an intraoral scanner (IOS) and a conventional impression for comparison with a reference aid. Materials and methods Four steel spheres were reversibly luted in the mandibular (n = 50) with a metallic reference aid at maximum mouth opening (MMO). Two digital impressions (Trios3), at MMO and at slightly mouth opening SMO and a conventional impression (Impregum), were taken as the measuring accuracy of the reference structure was already known. Difference between MMO-SMO for digital impressions and deviations between digital and conventional (SMO) were calculated. Furthermore, the angle between the normal vectors of two constructed planes was measured. Statistical analysis was performed with SPSS25. Results Deviations for linear distances ranged from −1 ± 3 μm up to 17 ± 78 μm (digital impressions, MMO-SMO), from 19 ± 16 μm up to 132 ± 90 μm (digital impressions, SMO), and from 28 ± 17 μm up to 60 ± 52 μm (conventional impressions, SMO). There were no significant differences for digital impressions (MMO-SMO), and there were significant differences between the conventional and digital impressions at SMO. Conclusions Based on the results of the present study, no mandibular deformation could be detected during mouth opening with regard to the digital impressions. The results were rather within the measuring tolerance of the intraoral scanner. Clinical relevance Based on the present study, no deformation of the mandibular during mouth opening could be observed at the level previously assumed. Therewith related, dental techniques related to a possible mandibular deformation therefore should be reconsidered.

Background Material extrusion is used to 3D print anatomic models and guides. Sterilization is required if a 3D printed part touches the patient during an intervention. Vaporized Hydrogen Peroxide (VHP) is one method of sterilization. There are four factors to consider when sterilizing an anatomic model or guide: sterility, biocompatibility, mechanical properties, and geometric fidelity. This project focuses on geometric fidelity for material extrusion of one polymer acrylonitrile butadiene styrene (ABS) using VHP. Methods De-identified computed tomography (CT) image data from 16 patients was segmented using Mimics Innovation Suite (Materialise NV, Leuven, Belgium). Eight patients had maxillary and mandibular defects depicted with the anatomic models, and eight had mandibular defects for the anatomic guides. Anatomic models and guides designed from the surfaces of CT scan reconstruction and segementation were 3D printed in medical-grade acrylonitrile butadiene styrene (ABS) material extrusion. The 16 parts underwent low-temperature sterilization with VHP. The dimensional error was estimated after sterilization by comparing scanned images of the 3D printed parts. Results The average of the estimated mean differences between the printed pieces before and after sterilization were − 0,011 ± 0,252 mm (95%CI − 0,011; − 0,010) for the models and 0,003 ± 0,057 mm (95%CI 0,002; 0,003) for the guides. Regarding the dimensional error of the sterilized parts compared to the original design, the estimated mean differences were − 0,082 ± 0,626 mm (95%CI − 0,083; − 0,081) for the models and 0,126 ± 0,205 mm (95%CI 0,126, 0,127) for the guides. Conclusion This project tested and verified dimensional stability, one of the four prerequisites for introducing vaporized hydrogen peroxide into 3D printing of anatomic models and guides; the 3D printed parts maintained dimensional stability after sterilization.

To develop a nasal-tragus length (NTL)-based table for estimating the endotracheal tube (ETT) insertion depth. A prospective study of 110 Thai neonates was conducted in a NICU in Bangkok, Thailand. The correlation between the optimal insertion depth (Opt-Depth) and NTL was determined, and then an NTL-based table for estimating ETT depth was developed. The accuracy of using various methods in estimating ETT depth was compared. A strong correlation between Opt-Depth and NTL was found (r = 0.897, p

We compared the accuracy of magnetic resonance (MR) urethrography and X-ray urethrography with operative findings for urethral strictures and observed their effects on treatment. A total of 87 male patients (10–85 years of age) treated from January 2015 to December 2016 were included in the study. X-ray and MR urethrograms were performed for all patients to determine the location, length, and degree of urethral strictures and the organizational structure around the urethra, and the results were compared with the operative findings. One-way analysis of variance (ANOVA) was performed to compare the lengths of the urethral strictures determined by the two methods with the operative findings. A value of P

The assumption of latent monotonicity is made by all common parametric and nonparametric polytomous item response theory models and is crucial for establishing an ordinal level of measurement of the item score. Three forms of latent monotonicity can be distinguished: monotonicity of the cumulative probabilities, of the continuation ratios, and of the adjacent-category ratios. Observable consequences of these different forms of latent monotonicity are derived, and Bayes factor methods for testing these consequences are proposed. These methods allow for the quantification of the evidence both in favor and against the tested property. Both item-level and category-level Bayes factors are considered, and their performance is evaluated using a simulation study. The methods are applied to an empirical example consisting of a 10-item Likert scale to investigate whether a polytomous item scoring rule results in item scores that are of ordinal level measurement. Electronic supplementary material The online version of this article (10.1007/s11336-019-09661-w) contains supplementary material, which is available to authorized users.

Background Hypertension is the most common chronic disease and is the leading cause of morbidity and mortality. Its screening, diagnosis, and management depend heavily on accurate blood pressure (BP) measurement. It is recommended that the diagnosis of hypertension should be confirmed or corroborated by out-of-office BP values, measured using ambulatory BP monitoring (ABPM) and home BP monitoring (HBPM). When office BP is used, automated office BP (AOBP) measurement method, which automatically provides an average of 3–5 BP readings, should be preferred. This study aimed to describe the BP measurement methods commonly used by doctors in primary care in Hong Kong, to screen, diagnose, and manage hypertensive patients. Methods In this cross-sectional survey, all doctors registered in the Hong Kong “Primary Care Directory” were mailed a questionnaire, asking their preferred BP-measuring methods to screen, diagnose, and manage hypertensive patients. Furthermore, we also elicited information on the usual number of office BP or HBPM readings obtained, to diagnose or manage hypertension. Results Of the 1738 doctors included from the directory, 445 responded. Manual measurement using a mercury or aneroid device was found to be the commonest method to screen (63.1%), diagnose (56.4%), and manage (72.4%) hypertension. There was a significant underutilisation of ABPM, with only 1.6% doctors using this method to diagnose hypertension. HBPM was used by 22.2% and 56.8% of the respondents to diagnose and manage hypertension, respectively. A quarter (26.7%) of the respondents reported using only one in-office BP reading, while around 40% participants reported using ≥12 HBPM readings. Doctors with specialist qualification in family medicine were more likely to use AOBP in clinics and to obtain the recommended number of office BP readings for diagnosis and management of hypertension. Conclusion Primary Care doctors in Hong Kong prefer to use manual office BP values, measured using mercury or aneroid devices, to screen, diagnose, and manage hypertension, highlighting a marked underutilisation of AOBP and out-of-office BP measuring techniques, especially that of ABPM. Further studies are indicated to understand the underlying reasons and to minimise the gap between real-life clinical practice and those recommended, based on scientific advances. Trial registration Clinicaltrial.gov; ref. no.: NCT03926897.

In computerized adaptive testing (CAT), a variable-length stopping rule refers to ending item administration after a pre-specified measurement precision standard has been satisfied. The goal is to provide equal measurement precision for all examinees regardless of their true latent trait level. Several stopping rules have been proposed in unidimensional CAT, such as the minimum information rule or the maximum standard error rule. These rules have also been extended to multidimensional CAT and cognitive diagnostic CAT, and they all share the same idea of monitoring measurement error. Recently, Babcock and Weiss (J Comput Adapt Test 2012. https://doi.org/10.7333/1212-0101001) proposed an "absolute change in theta" (CT) rule, which is useful when an item bank is exhaustive of good items for one or more ranges of the trait continuum. Choi, Grady and Dodd (Educ Psychol Meas 70:1-17, 2010) also argued that a CAT should stop when the standard error does not change, implying that the item bank is likely exhausted. Although these stopping rules have been evaluated and compared in different simulation studies, the relationships among the various rules remain unclear, and therefore there lacks a clear guideline regarding when to use which rule. This paper presents analytic results to show the connections among various stopping rules within both unidimensional and multidimensional CAT. In particular, it is argued that the CT-rule alone can be unstable and it can end the test prematurely. However, the CT-rule can be a useful secondary rule to monitor the point of diminished returns. To further provide empirical evidence, three simulation studies are reported using both the 2PL model and the multidimensional graded response model.

The purpose of the present study was to determine which factors affect the positional accuracy of iliosacral screws inserted using 3D fluoroscopic navigation. Specifically, we asked: (1) does the screw insertion angle in the coronal and axial planes affect the positional accuracy of iliosacral screw insertion using 3D fluoroscopic navigation? (2) Is the positional accuracy of iliosacral screw insertion using 3D fluoroscopic navigation affected by the type of screw (transsacral versus standard iliosacral), site of screw insertion (S1 versus S2), patient position (supine versus prone), presence of a dysmorphic sacrum, or AO/OTA classification (type B versus C)? Twenty-seven patients with AO/OTA type B or C pelvic ring fracture were treated by percutaneous iliosacral screw fixation. A total of 55 screws were inserted into S1 or S2 using 3D fluoroscopic navigation combined with preoperative CT-based planning. The positional accuracy of screw placement was assessed by matching postoperative CT images with preoperative CT images. The distance between the central axis of the inserted screw and that of the planned screw placement was measured in the sagittal plane passing through the center of the vertebral body. The mean deviation between the planned and the inserted screw position was 2.9 ± 1.7 mm (range 0–8.5 mm) at the vertebral body center. Multiple regression analysis showed that the screw insertion angle relative to the vertical line of the bone surface in the axial plane (β = 0.354, p = 0.013) and the use of a transsacral screw (β = 0.317, p = 0.017) were correlated with the positional accuracy of screw placement (adjusted R2 = 0.276, p = 0.002). A greater screw insertion angle relative to the vertical line on the bone surface and the use of transsacral screws increases the positional error of iliosacral screws inserted using 3D fluoroscopic navigation. Level IV, therapeutic study.

The number of patients above 40 years suffering an anterior shoulder dislocation for the first time has recently increased. This study investigated the role of glenoid version, inclination and rotator interval dimension in patients older than 40 years with an anterior shoulder dislocation. We hypothesize that the rotator interval plays a more important role than the osseus alignment in older patients. Patients aged older than 40 years with a traumatic shoulder dislocation were compared with patients who had undergone magnetic resonance imaging (MRI) for a different reason. The MRIs of 61 dislocation group patients were compared with MRIs of 73 comparison group patients. Two shoulder surgeons measured glenoid version, inclination, height and width, rotator interval (RI) height, base (width) and area. The study and comparison group consisted of 61 patients with a mean age of 59 ± 9 years and 73 patients with a mean age of 57 ± 12, respectively. The mean glenoid version of the dislocation group was − 4.9° ± 4.4° (retroversion) and mean inclination was 9.8° ± 8° (reclination). Mean rotator interval base, height and the rotator interval area was 46 ± 6 mm, 14 ± 5 mm and 33 ± 14 mm2, respectively. The comparison group had a mean glenoid version of − 5.4° ± 5.4° and a mean inclination of 10.8° ± 6.2°. The rotator interval base was 41 ± 6 mm, the height was 16 ± 4 mm and the area was 34 ± 11 mm2. The between-group differences were statistically significant for rotator interval height and base (p

The recent guidelines recommend using the estimated glomerular filtration rate (eGFR) to evaluate renal function. There are two reported full-age-spectrum (FAS) equations in 2017, which are based on serum cystatin C concentrations with or without accompanying serum creatinine level (FASCr–Cys or FASCys). We compared the performance and assessed the applicability of the new FAS equation with the 2012 CKD-EPI (CKD-EPICys and CKD-EPICr–Cys) equation in Chinese subjects. A total of 1184 patients, mean aged 55.06 year who underwent 99mTc-DTPA GFR measurements (rGFR) from four hospitals were enrolled. The bias (eGFR-rGFR), precision (interquartile range of difference [IQR]), and accuracy (the proportion of eGFR within 30% of rGFR [P30]) of eGFR and rGFR calculated by four equations were compared. Generally, the equation based on the combination of Cys and Scr performed superior to that on the basis of Cys alone, either the CKD-EPICr–Cys or the FASCr–Cys. Detailedly, referred to rGFR (67.33 ml/min/1.73 m2), the CKD-EPICys, CKD-EPICr–Cys, FASCys, and the FASCr–Cys estimated GFR 56.46 ml/min/1.73 m2, 62.79 ml/min/1.73 m2, 56.45 ml/min/1.73 m2, and 61.04 ml/min/1.73 m2, gave ROCAUC0.944, 0.954, 0.943, and 0.953, respectively. Another comparison as to bias, precision, P30, and RMSE with FASCr–Cys were − 2.87 ml/min/1.73 m2, 19.01 ml/min/1.73 m2, 74.16%, and 17.84 ml/min/1.73 m2 showed that FASCr–Cys performed approximately more accurate than other equations, as well as the diagnostic consistency of GFR staging. In the rGFR 70%. The performance of the FASCr–Cys equation is better than that of the CKD-EPICr–Cys equation in the Chinese population, particularly in the elderly. Yet, further modification of FAS equations from a large-scale study could be more suitable for the Chinese population, particularly in older people.

Laparoscopic subtotal gastrectomy (LsTG) has several advantages, including technical safety and preservation of postoperative function, compared with total or proximal gastrectomy for early gastric cancer. However, LsTG has some technical issues with respect to achieving a safe resection margin and patency in patients with lesions close to the cardia or fornix. When LsTG is performed for lesions located rather close to the cardia or fornix, conventional marking clips can physically hinder transection by an endoscopic linear stapler. Additionally, tracing the tumor boundary to create a precise resection line is difficult. To resolve these issues, we introduced a new marking technique called endoscopic cautery marking (ECM) involving the creation of small cauterized spots. Of 791 patients who underwent laparoscopic gastrectomy from 2015 to 2017, 16 underwent LsTG with ECM. Before surgery, ECM was performed and the pathological tumor boundary was traced according to preoperative biopsies. Under intraoperative endoscopic guidance, we divided the stomach with an endoscopic linear stapler on the proximal side of the ECM site and examined the stump by pathological frozen section analysis to confirm the absence of cancer. The median length of the endoscopically measured distance from the esophagogastric junction to the tumor was 30.0 mm (range 15–40 mm), and the median pathological proximal margin was 11.5 mm (range 0–26 mm). Although the ECM site was completely resected in all patients, frozen section analysis showed a positive margin in one lesion, which had an unclear tumor boundary due to gastritis. For this patient, we converted the procedure to laparoscopic completion gastrectomy. No severe complications or recurrences occurred. LsTG with ECM was technically feasible, and short-term outcomes were acceptable in this preliminary study. Further experience and investigations are imperative to verify the oncological and functional implications of LsTG with ECM.

To validate current eligibility criteria for focal therapy (FT) in prostate cancer men undergoing radical prostatectomy (RP) and to assess the role of magnetic resonance imaging (MRI). Retrospective analysis of 217 RP patients (2009–2016) with preoperative MRI (almost all in external institutions) and fulfillment of different FT eligibility criteria: unilateral tumor, clinical tumor stage ≤ cT2a, prostate volume ≤ 60 mL and either biopsy Gleason 3 + 3 or ≤ 3 + 4 and PSA ≤ 10 or ≤ 15 ng/mL. Multivariable logistic regression analyses (MVA) assessed the role of MRI to predict the presence of significant contralateral tumor or extracapsular extension (ECE), including seminal vesicle invasion. To quantify model accuracy, Receiver Operating Characteristics-derived area under the curve (AUC) was used. Of 217 patients fulfilling widest biopsy criteria and 113 fulfilling additional MRI criteria, 64 (29.7%) and 37 (32.7%) remained eligible for FT according to histopathological results. In MVA, fulfillment of MRI criteria reached independent predictor status for prediction of contralateral tumor but not for ECE. Addition of MRI resulted in AUC gain (57.5–64.6%). Sensitivity, specificity, PPV and NPV for MRI to predict contralateral tumor were: 41.8, 71.6, 70.9 and 42.6%, respectively. Virtually the same results were recorded for Gleason 3 + 3 and/or PSA ≤ 10 ng/mL. Patient eligibility criteria for FT using biopsy criteria remained insufficient with respect to contralateral tumor disease. Although, MRI improves accuracy, it cannot safely exclude or minimize chance of significant cancer on contralateral prostate side. To date, stricter eligibility criteria are needed to provide more diagnostic reliability.

To evaluate the detection rate among three different targeted biopsy approaches of robot-assisted MRI/TRUS fusion (RA-TB), mpMRI in-bore (MRGB), cognitive fusion guidance biopsy (COG-TB) for the detection of prostate cancer (PC) and clinically significant PC (csPC). Between 2014 and 2016, 156 patients with a lesion on mpMRI, performed in accordance with ESUR guidelines, due to cancer suspicion or on-going cancer suspicion after prior negative prostate biopsy, underwent targeted biopsy with RA-TB, MRGB or COG-TB. All lesions were rated according to PI-RADS v2. We compared detection rates between techniques. Models were constructed to predict the detection of overall PC and csPC and using a 1000 boot-strap sample. In the all cohort, 73, 45 and 38 patients underwent RA-TB, MRGB or COG-TB, respectively. Overall PC was found in 39 (52.42%), 23 (51.11%) and 11 (28.95%) (p = 0.04) patients of RA-TB, MRGB and COG-TB arm, respectively. As concerning the detection of csPC, it was found in 26 (35.62%),18 (40.0%) and 9 (23.68%) patients of RA-TB, MRGB and COG-TB arm (p = 0.27). Model 1 showed that RA-TB [OR: 10.08 (95% CI 1.95–51.97); p

Innovative imaging modalities are applied for diagnosing and follow-up of prostate cancer (PCa). To perform authentic targeted biopsies and evaluate prostate changes, it is essential to reliably identify and hit targets in their true anatomical location over time. A newly described image correlation method (Internal Fusion) allows precise correlation of serial transrectal ultrasound (TRUS) images in vitro and vivo. Identifiable morphologic structures such as prostatic calcifications define internal anchor points (Internal Landmarks) to facilitate exact correlation. After verification of Internal Fusion in vitro, 83 patients were included from January to August 2017 with at least one prior series of 5-mm spaced TRUS images stored as computed tomographic (US-CT) online data set. Two experienced operators collected new images in correlation with each cross-section of the previous examinations based on Internal Landmarks. Of the 83 patients, fifty (60%) had prior negative biopsies. Fourteen (17%) wished US-CT targeted biopsies and PCa were detected in 7/14 patients (50%). Overall, accurate imaging correlations were attained in 369/397 slices (93%). In initial and repeat biopsy, 31/31 and 35/35 images could be correlated detecting PCa in 5/8 (63%) and 2/6 patients (33%). The longest observation of prostate changes over time (Trend Monitoring) with accurate image correlation was 8 years and 6 months. Internal Fusion by Internal Landmarks ensures exact correlation in long-term follow-up. It is possible to precisely monitor trends in prostate tissue changes. In case of PCa suspicion, biopsies could be targeted with high accuracy by Internal Fusion, even over time.

Clinical staging is vital for treatment decision-making by renal cell carcinoma (RCC) patients. Some RCCs clinically appear T1 on CT, but are actually T3a due to extension into fat or renal vein, causing the tumor to be pathologically upstaged. The objective of this study to determine the rate, survival, and predictors of RCC upstaging, for patients with cT1 disease treated surgically. Using the National Cancer Data Base Participant User File for RCC from 2004 to 2013, we selected AJCC cT1 patients, who underwent surgical resection and whose AJCC pathological T stage (pT) was available. Upstaging was characterized dichotomously—overall (any pT > T1) and pT3a-specific upstaging. Patient and tumor characteristics of those upstaged and not were compared using Chi-squared analyses. Multivariable logistic regression was used to analyze predictors of upstaging, and Cox proportional hazards regression was used to estimate overall survival hazards ratios. Overall upstaging (pT > T1) was observed in 8252 (7.1%) patients, and T3a-specific upstaging was observed in 3380 (5.4%) patients. Patients who were older, male, and had comorbidities, and tumors that were cT1b, underwent RN, and had high Fuhrman grade were at a higher risk of pathological upstaging. Upstaging led to a 40% increased risk of death compared to patients who were not upstaged. The rate of upstaging is not negligible (5–7% of the time), negatively impacts survival, and various patient and tumor characteristics can be used to predict upstaging.

Nasal-tragus length (NTL) estimates of endotracheal tube (ETT) depth are replacing weight-based estimates for endotracheal tube depth in neonates requiring endotracheal intubation. Existing neonatal simulators were designed before interest in using the NTL, and may lack fidelity in this measurement. The objective of this study is to evaluate the accuracy of the adjusted NTL formula and the Neonatal Resuscitation Program (NRP) gestational age/weight-based ETT depth chart in predicting proper endotracheal tube insertion depth in a cohort of neonatal simulators. The NTL and appropriate intubation depth to the mid-trachea were measured for 11 commonly used neonatal intubation simulators. The NTL+1 cm formula incorrectly estimates the mid-tracheal depth in 82% of simulators, and the weight-based chart incorrectly estimates depth in 75% of test simulators. Only one simulator experienced a mainstem intubation with ETT insertion to the depth predicted by the NTL+1 cm formula. The majority of neonatal resuscitation simulations lacked physical fidelity with regard to mid-tracheal ETT insertion depth. The NRP gestational age/weight-based chart outperformed the NTL+1 cm formula but still resulted in endotracheal tube misplacement in the majority of neonatal simulators. The majority of simulators had adequate functional fidelity using either method for ETT depth estimation.

Measurement of bowel length is an essential surgical skill for laparoscopic and open gastrointestinal surgery in order to achieve favorable outcomes and avoid long-term complications. Variations in accuracy between the two surgical approaches may exist. However, only few studies have tried to assess these differences. Our aim was to assess reliability and inter-rater variability of small bowel length assessment during laparoscopy in an in vivo porcine model. This is a single-institution, double-blinded, technical assessment study in a porcine in vivo model. Fourteen participants (ten senior surgeons with >1000 laparoscopic procedures and four junior surgeons) had to assess and mark lengths of small bowel in both laparoscopic and open surgical approaches. Each participant was assigned to measure and mark specific, randomized distances (range 25–197 cm) in both laparoscopic and open approaches using color-coded vessel loops. Actual participant-marked distances were compared to the assigned distances followed by Bland–Altman plots and linear regression analysis to determine accuracy and proportional error trends. Study data were further compared to available data sets from previously published studies. Laparoscopy measurements were significantly shorter than required (difference 33.8 ± 28.7 cm, P

The usage of psychological networks that conceptualize psychological behavior as a complex interplay of psychological and other components has gained increasing popularity in various fields of psychology. While prior publications have tackled the topics of estimating and interpreting such networks, little work has been conducted to check how accurate (i.e., prone to sampling variation) networks are estimated, and how stable (i.e., interpretation remains similar with less observations) inferences from the network structure (such as centrality indices) are. In this tutorial paper, we aim to introduce the reader to this field and tackle the problem of accuracy under sampling variation. We first introduce the current state-of-the-art of network estimation. Second, we provide a rationale why researchers should investigate the accuracy of psychological networks. Third, we describe how bootstrap routines can be used to (A) assess the accuracy of estimated network connections, (B) investigate the stability of centrality indices, and (C) test whether network connections and centrality estimates for different variables differ from each other. We introduce two novel statistical methods: for (B) the correlation stability coefficient, and for (C) the bootstrapped difference test for edge-weights and centrality indices. We conducted and present simulation studies to assess the performance of both methods. Finally, we developed the free R-package bootnet that allows for estimating psychological networks in a generalized framework in addition to the proposed bootstrap methods. We showcase bootnet in a tutorial, accompanied by R syntax, in which we analyze a dataset of 359 women with posttraumatic stress disorder available online., Comment: Accepted for publication in Behavior Research Methods

The aim of this study was to compare the American Gastroenterological Association guidelines (AGA criteria), the 2012 (Fukuoka criteria), and 2006 (Sendai criteria) International Consensus Guidelines for the diagnosis of advanced pancreatic cystic neoplasms. All patients who underwent surgical resection of a pancreatic cyst from August 2007 through January 2016 were retrospectively analyzed at a single tertiary academic center. Relevant clinical and imaging variables along with pathology results were collected to determine appropriate classification for each guideline. Advanced pancreatic cystic neoplasms were defined by the presence of either high-grade dysplasia or cystic adenocarcinoma. Diagnostic accuracy was measured by ROC analysis. A total of 209 patients were included. Both the AGA and Fukuoka criteria had a higher diagnostic accuracy for advanced neoplastic cysts than the Sendai criteria: AGA ROC 0.76 (95% CI 0.69–0.81), Fukuoka ROC 0.78 (95% CI 0.74–0.82), and Sendai ROC 0.65 (95% CI 0.61–0.69) (p

To verify whether the new Asian modified CKD-EPI equation improved the performance of original one in determining GFR in Chinese patients with CKD. A well-designed paired cohort was set up. Measured GFR (mGFR) was the result of 99mTc-diethylene triamine pentaacetic acid (99mTc-DTPA) dual plasma sample clearance method. The estimated GFR (eGFR) was the result of the CKD-EPI equation (eGFR1) and the new Asian modified CKD-EPI equation (eGFR2). The comparisons were performed to evaluate the superiority of the eGFR2 in bias, accuracy, precision, concordance correlation coefficient and the slope of regression equation and measure agreement. A total of 195 patients were enrolled and analyzed. The new Asian modified CKD-EPI equation improved the performance of the original one in bias and accuracy. However, nearly identical performance was observed in the respect of precision, concordance correlation coefficient, slope of eGFR against mGFR and 95 % limit of agreement. In the subgroup of GFR 60 mL min−1/1.73 m2, eGFR2 performed better than eGFR1 in terms of bias and accuracy. The new Asian modified CKD-EPI equation can lead to more accurate GFR estimation in Chinese patients with CKD in general practice, especially in the higher GFR group.

To compare interobserver agreements among multiple readers and accuracy for the assessment of solid components in subsolid nodules between the lung and mediastinal window settings. Seventy-seven surgically resected nodules with solid components smaller than 8 mm were included in this study. In both lung and mediastinal windows, five readers independently assessed the presence and size of solid component. Bootstrapping was used to compare the interobserver agreement between the two window settings. Imaging-pathology correlation was performed to evaluate the accuracy. There were no significant differences in the interobserver agreements between the two windows for both identification (lung windows, k = 0.51; mediastinal windows, k = 0.57) and measurements (lung windows, ICC = 0.70; mediastinal windows, ICC = 0.69) of solid components. The incidence of false negative results for the presence of invasive components and the median absolute difference between the solid component size and the invasive component size were significantly higher on mediastinal windows than on lung windows (P

Direct and indirect digitalization offer two options for computer-aided design (CAD)/ computer-aided manufacturing (CAM)-generated restorations. The aim of this study was to evaluate the accuracy of different intraoral scanners and compare them to the process of indirect digitalization. A titanium testing model was directly digitized 12 times with each intraoral scanner: (1) CS 3500 (CS), (2) Zfx Intrascan (ZFX), (3) CEREC AC Bluecam (BLU), (4) CEREC AC Omnicam (OC) and (5) True Definition (TD). As control, 12 polyether impressions were taken and the referring plaster casts were digitized indirectly with the D-810 laboratory scanner (CON). The accuracy (trueness/precision) of the datasets was evaluated by an analysing software (Geomagic Qualify 12.1) using a “best fit alignment” of the datasets with a highly accurate reference dataset of the testing model, received from industrial computed tomography. Direct digitalization using the TD showed the significant highest overall “trueness”, followed by CS. Both performed better than CON. BLU, ZFX and OC showed higher differences from the reference dataset than CON. Regarding the overall “precision”, the CS 3500 intraoral scanner and the True Definition showed the best performance. CON, BLU and OC resulted in significantly higher precision than ZFX did. Within the limitations of this in vitro study, the accuracy of the ascertained datasets was dependent on the scanning system. The direct digitalization was not superior to indirect digitalization for all tested systems. Regarding the accuracy, all tested intraoral scanning technologies seem to be able to reproduce a single quadrant within clinical acceptable accuracy. However, differences were detected between the tested systems.

Background The optimal procedure for maximizing the diagnostic yield and minimizing the procedural complexity of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is controversial. We conducted a prospective randomized controlled trial to determine the optimal procedure of EBUS-TBNA for mediastinal and hilar lymphadenopathy, with a particular focus on the roles of the inner-stylet and suction. Methods Consecutive patients with enlarged mediastinal and hilar lymph nodes (LNs), detected by computed tomography (CT) or positron emission tomography-CT (PET-CT), who underwent EBUS-TBNA were included. Each LN was sampled with three needle passes using suction–stylet, suction–no stylet, and stylet–no suction procedures. The samples were smeared onto glass slides for cytological evaluation. A single, blinded cytopathologist evaluated each set of slides. The primary outcomes were cytological specimen adequacy rate and diagnostic yield of malignant LNs. The secondary outcomes were tissue-core acquisition rate, procedural time, and the amount of bleeding. Results This study evaluated 97 patients with a total of 255 LNs. The final LN diagnosis was benign in 144, malignant in 104, and inadequate in 7 cases. There were no significant differences among the suction–stylet, suction–no stylet, and stylet–no suction groups in specimen adequacy rate (87.1, 88.2, 85.9%, respectively) or diagnostic yield of malignancy (32.2, 31.8, 31.0%, respectively). However, the use of suction was associated with an increase in tissue-core acquisition rate (P

Background Ultrasonography is essential in the prenatal diagnosis and care for the pregnant mothers. However, the measurements obtained often contain a small percentage of unavoidable error that may have serious clinical implications if substantial. We therefore evaluated the level of intra and inter-observer error in measuring mean sac diameter (MSD) and crown-rump length (CRL) in women between 6 and 10 weeks’ gestation at Mulago hospital. Methods This was a cross-sectional study conducted from January to March 2016. We enrolled 56 women with an intrauterine single viable embryo. The women were scanned using a transvaginal (TVS) technique by two observers who were blinded of each other’s measurements. Each observer measured the CRL twice and the MSD once for each woman. Intra-class correlation coefficients (ICCs), 95% limits of agreement (LOA) and technical error of measurement (TEM) were used for analysis. Results Intra-observer ICCs for CRL measurements were 0.995 and 0.993 while inter-observer ICCs were 0.988 for CRL and 0.955 for MSD measurements. Intra-observer 95% LOA for CRL were ± 2.04 mm and ± 1.66 mm. Inter-observer LOA were ± 2.35 mm for CRL and ± 4.87 mm for MSD. The intra-observer relative TEM for CRL were 4.62% and 3.70% whereas inter-observer relative TEM were 5.88% and 5.93% for CRL and MSD respectively. Conclusions Intra- and inter-observer error of CRL and MSD measurements among pregnant women at Mulago hospital were acceptable. This implies that at Mulago hospital, the error in pregnancy dating is within acceptable margins of ±3 days in first trimester, and the CRL and MSD cut offs of ≥7 mm and ≥ 25 mm respectively are fit for diagnosis of miscarriage on TVS. These findings should be extrapolated to the whole country with caution. Sonographers can achieve acceptable and comparable diagnostic accuracy levels of MSD and CLR measurements with proper training and adherence to practice guidelines.

The aim of this study was to assess the mental representation of the insertion axis of surgeons with different degrees of experience, and reproducibility of the insertion axis in repeated measures. A mastoidectomy and a posterior tympanotomy were prepared in five different artificial temporal bones. A cone-beam CT was performed for each temporal bone and the data were registered on a magnetic navigation system. In these five temporal bones, 16 surgeons (3 experts; >50 cochlear implant surgery/year; 7 fellows with few cochlear implant experience, and 6 residents) were asked to determine the optimal insertion axis according to their mental representation. Compared to a planned ideal axis, the insertion axis was better determined by the experts with higher accuracy (axial: 7° ± 1.5°, coronal: 6° ± 1.5°) than fellows (axial: 14° ± 1.7°, coronal: 13° ± 1.7°; p < 0.05), or residents (axial: 15° ± 1.5°; p < 0.001, coronal: 17° ± 1.9°; p < 0.001). This study suggests that mental representation of the cochlea is experience-dependent. A high variation of the insertion axis to the scala tympani can be observed due to the complexity of the temporal bone anatomy and lack of landmarks to determine scala tympani orientation. Navigation systems can be used to evaluate and improve mental representation of the insertion axis to the scala tympani for cochlear implant surgery.

The aim of the present study was to design a microscopy image analysis (MIA) system for predicting the 5-year survival of patients with laryngeal squamous cell carcinoma, employing histopathology images of lesions, which had been immunohistochemically (IHC) stained for p63 expression. Biopsy materials from 42 patients, with verified laryngeal cancer and follow-up, were selected from the archives of the University Hospital of Patras, Greece. Twenty six patients had survived more than 5 years and 16 less than 5 years after the first diagnosis. Histopathology images were IHC stained for p63 expression. Images were first processed by a segmentation method for isolating the p63-expressed nuclei. Seventy-seven features were evaluated regarding texture, shape, and physical topology of nuclei, p63 staining, and patient-specific data. Those features, the probabilistic neural network classifier, the leave-one-out (LOO), and the bootstrap cross-validation methods, were used to design the MIA-system for assessing the 5-year survival of patients with laryngeal cancer. MIA-system accuracy was about 90 % and 85 %, employing the LOO and the Bootstrap methods, respectively. The image texture of p63-expressed nuclei appeared coarser and contained more edges in the 5-year non-survivor group. These differences were at a statistically significant level (p < 0.05). In conclusion, this study has proposed an MIA-system that may be of assistance to physicians, as a second opinion tool in assessing the 5-year survival of patients with laryngeal cancer, and it has revealed useful information regarding differences in nuclei texture between 5-year survivors and non-survivors.

Flat-detector CT can be integrated with C-arm fluoroscopy for CT-guided neurosurgical and endovascular procedures. We studied the accuracy of this technique with laser assistance in targeting intracranial lesions in a cranial model. An acrylic scale-model skull containing foam parenchyma was embedded with 2.16-mm-diameter targets. A flat-detector CT was acquired and registered to the skull’s position. Ten targets were accessed with biopsy needles under fluoroscopic guidance, flat-detector CT overlay, and laser assistance. Accuracy was measured from the needle tip to the target center using flat-detector CT. Ten targets were accessed successfully using XperGuide software. Needles were placed within 1.30 $$\pm $$ 0.63 mm of target isocenter. Accuracy did not vary by entry site, operator, location, or lesion depth. Laser-assisted flat-detector CT-guided targeting of all intracranial targets was successful with excellent accuracy. This technique can be applied to other minimally invasive neurosurgical procedures.

The broad availability of cheap three-dimensional (3D) printing equipment has raised the need for a thorough analysis on its effects on clinical accuracy. Our aim is to determine whether the accuracy of 3D printing process is affected by the use of a low-budget workflow based on open source software and consumer’s commercially available 3D printers. A group of test objects was scanned with a 64-slice computed tomography (CT) in order to build their 3D copies. CT datasets were elaborated using a software chain based on three free and open source software. Objects were printed out with a commercially available 3D printer. Both the 3D copies and the test objects were measured using a digital professional caliper. Overall, the objects’ mean absolute difference between test objects and 3D copies is 0.23 mm and the mean relative difference amounts to 0.55 %. Our results demonstrate that the accuracy of 3D printing process remains high despite the use of a low-budget workflow.

Motion-mode (MM) echography allows precise measurement of diaphragmatic excursion when the ultrasound beam is parallel to the diaphragmatic displacement. However, proper alignment is difficult to obtain in patients after cardiac surgery; thus, measurements might be inaccurate. A new imaging modality named the anatomical motion-mode (AMM) allows free placement of the cursor through the numerical image reconstruction and perfect alignment with the diaphragmatic motion. Our goal was to compare MM and AMM measurements of diaphragmatic excursion in cardiac surgical patients. Cardiac surgical patients were studied after extubation. The excursions of the right and left hemidiaphragms were measured by two operators, an expert and a trainee, using MM and AMM successively, according to a blinded, randomized, crossover sequence. Values were averaged over three consecutive respiratory cycles. The angle between the MM and AMM cursors was quantified for each measurement. Fifty patients were studied. The mean (±SD) angle between the MM and AMM cursors was 37° ± 16°. The diaphragmatic excursion as measured by experts was 1.8 ± 0.7 cm using MM and 1.5 ± 0.5 cm using AMM (p

Background Accurate measurement of renal function is important: however, radiolabelled gold standard measurement of GFR is highly expensive and can only be used on a very limited scale. We aim to compare the performance of Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equations in the multi-ethnic population attending University Malaya Medical Centre (UMMC). Methods This is a cross-sectional study recruiting patients, who attend UMMC Nephrology clinics on voluntary basis. 51-Chromium EDTA (51Cr-EDTA) plasma level was used to measure the reference GFR. The serum creatinine was determined by IDMS reference modified Jaffe kinetic assay (CrJaffe). The predictive capabilities of MDRD and CKD-EPI based equations were calculated. Data was analysed using SPSS version 20 and correlation, bias, precision and accuracy were determined. Results A total of 113 subjects with mean age of 58.12 ± 14.76 years and BMI of 25.99 ± 4.29 kg/m2 were recruited. The mean reference GFR was 66.98 ± 40.65 ml/min/1.73m2, while the estimated GFR based on MDRD and CKD-EPI formula were 62.17 ± 40.40, and 60.44 ± 34.59, respectively. Both MDRD and CKD-EPI were well-correlated with reference GFR (0.806 and 0.867 respectively) and statistically significant with p

Referral for an assessment of tall stature is less common than for short stature. Tall stature is defined as a height more than two standard deviations above the mean for age. The majority of subjects with tall stature show a familial tall stature or a constitutional advance of growth (CAG), which is a diagnosis of exclusion. After a careful physical evaluation, tall subjects may be divided into two groups: tall subjects with normal appearance and tall subjects with abnormal appearance. In the case of normal appearance, the paediatric endocrinologist will have to evaluate the growth rate. If it is normal for age and sex, the subject may be classified as having familial tall stature, CAG or obese subject, while if the growth rate is increased it is essential to evaluate pubertal status and thyroid status. Tall subjects with abnormal appearance and dysmorphisms can be classified into those with proportionate and disproportionate syndromes. A careful physical examination and an evaluation of growth pattern are required before starting further investigations. Physicians should always search for a pathological cause of tall stature, although the majority of children are healthy and they generally do not need treatment to cease growth progression. The most accepted and effective treatment for an excessive height prediction is inducing puberty early and leading to a complete fusion of the epiphyses and achievement of final height, using testosterone in males and oestrogens in females. Alternatively, the most common surgical procedure for reducing growth is bilateral percutaneous epiphysiodesis of the distal femur and proximal tibia and fibula. This review aims to provide up-to-date information and suggestions about the diagnosis and management of children with tall stature.

The objective of this study was to improve the evaluation of unilateral vocal fold paralyses (uVFP) by means of an area measurement of the glottic plane, which describes the position of the paralysed vocal fold. The area measurements were related to electromyographic findings and clinical outcome (recovery, voice quality). In 56 patients (33 women and 23 men), uVFP were confirmed by endolaryngeal electromyography (EMG) of the paralysed vocal fold and cricothyroid muscles (CT). The EMG response was classified on a 4-point scale (from 0 to 3). Vocal fold position was divided into 'paramedian' and 'intermediate' and additionally quantified by measurement of the glottic area. An 'area quotient' (AQ) was calculated and related to the EMG findings and clinical outcome. Voice qualities were objectified regarding their additive noise (breathiness) and irregularity (roughness) using the 'Göttingen Hoarseness Diagram'. The majority of uVFP was due to iatrogenic lesions. The AQ of classically graduated 'paramedian' and 'intermediate' vocal fold positions was significantly different but did not correlate with objective voice quality values. There were no significant correlations regarding EMG findings, duration or recovery from paralyses. Laryngeal EMG remains the gold standard for verifying uVFP. But EMG did not correlate significantly with AQ or functional outcome of uVFP. The measurement of an AQ is suitable for obtaining continuous data describing the position of paralysed vocal folds beyond the terms 'paramedian' or 'intermediate' and provides the basis for clinical evaluations of diagnostic tools and therapeutic interventions.

Current methods of measuring gross motor abilities in children involve either high-cost specialist apparatus that is unsuitable for use in schools, or low-cost but nonoptimal observational measures. We describe the development of a low-cost system that is capable of providing high-quality objective data for the measurement of head movements and postural sway. This system is based on off-the-shelf components available for the Nintendo Wii: (1) The infrared cameras in a pair of WiiMotes are used to track head movements by resolving the position of infrared-emitting diodes in three dimensions, and (2) center-of-pressure data are captured using the WiiFit Balance board. This allows the assessment of children in school settings, and thus provides a mechanism for identifying children with neurological problems affecting posture. In order to test the utility of the system, we installed the apparatus in two schools to determine whether we could collect meaningful data on hundreds of children in a short time period. The system was successfully deployed in each school over a week, and data were collected on all of the children within the school buildings at the time of testing (N = 269). The data showed reliable effects of age and viewing condition, as predicted from previous small-scale studies that had used specialist apparatus to measure childhood posture. Thus, our system has the potential to allow screening of children for gross postural deficits in a manner that has never previously been possible. It follows that our system opens up the possibility of conducting large-scale behavioral studies concerning the development of posture.

Measurement of volumetric change after aesthetic and reconstructive breast surgery is of great significance to plastic surgeons. This study aimed to investigate the influence of respiration on measurement of breast volumetric change via a three-dimensional (3D) scanning technique. In this study, ten augmentation mammaplasty patients received preoperative 3D scanning in different respiration states at three time points: the end of normal exhalation (ENE1), the end of normal inhalation (ENI), and the end of normal exhalation again (ENE2). Using Geomagic Studio 12 software, breast volumetric change error (BVCE) was measured between the ENE1 scan and the ENI scan (R1) and between the ENE1 scan and ENE2 scan (R2). Three-dimensional deviation, defined as the shortest distance from one scan to any point on the other scan, was measured in R1 and R2. A paired-sample t test was used to compare the means of BVCE and the 3D deviation between R1 and R2. Pearson’s correlation coefficient was calculated between 3D deviation and BVCE. For the analysis, SPSS program version 16 was used. Differences were considered statistically significant at P values lower than 0.05. The mean breast volume was 352.3 ± 52.7 ml, and BVCE was significantly lower in R1 than in R2 (9.7 vs. 21.3 ml; P = 0.000). The 3D deviation was significantly higher in R2 than in R1 (1.600 vs. 0.887; P = 0.000). In the analysis, BVCE was not correlated significantly with 3D deviation in R1 (P = 0.157) but was significantly correlated with 3D deviation in R2 (correlation coefficient = 0.766; P = 0.000). Keeping patients in the same respiration state is crucial for accurate measurement of breast volumetric change via the 3D scanning technique. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The article introduces a new method for three-dimensional reproduction of edentulous dental casts, and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering software and evaluates the method's accuracy in vitro. The method comprises three main steps: (i) acquisition of the three-dimensional stereolithography data of maxillary and mandibular edentulous dental casts and wax occlusion rims; (ii) acquisition of the three-dimensional stereolithography data of jaw relations; and (iii) registration of these data with the reverse engineering software and completing reconstruction. To evaluate the accuracy of this method, dental casts and wax occlusion rims of 10 edentulous patients were used. The lengths of eight lines between common anatomic landmarks were measured directly on the casts and occlusion rims by using a vernier caliper and on the three-dimensional computerized images by using the software measurement tool. The direct data were considered as the true values. The paired-samples t-test was used for statistical analysis. The mean differences between the direct and the computerized measurements were mostly less than 0.04 mm and were not significant (P>0.05). Statistical significance among 10 patients was assessed using one-way analysis of variance (P

The aim of this study was to examine the biochemical composition of pericardial effusions of different etiology and to evaluate the diagnostic utility of biochemical parameters and tumor markers to discriminate malignant from benign effusion. Pericardial and serum levels of biochemical parameters and tumor markers were compared in 105 patients who underwent pericardiocentesis and pericardioscopy with targeted epicardial biopsy. Etiologic diagnosis was based on pericardial fluid and epicardial biopsy analysis by cytology, histology, immunohistochemistry, microbiology and polymerase chain reaction. The total of 105 patients comprised 29 patients with malignant and 76 patients with non-malignant pericardial effusions (40 autoreactive, 28 viral, 5 postcardiotomy syndromes and 3 associated with systemic diseases). Malignant pericardial effusions had significantly higher pericardial fluid levels of the tumor markers CEA, CA 19-9, CA 72-4, SCC and NSE (p < 0.001, p = 0.002, p < 0.001, p = 0.004 and p < 0.001, respectively) as well as higher pericardial fluid hemoglobin (p < 0.001), pericardial fluid white blood cells (p = 0.003), pericardial fluid LDH (p < 0.001) and ratio of pericardial to serum LDH levels compared to benign effusions. None of the biochemical or cell-count parameters tested proved to be accurate enough for distinguishing malignant from benign effusions. However, measurement of pericardial CA 72-4 levels offered a high diagnostic accuracy for malignancy, particularly in bloody pericardial effusions. None of the biochemical parameters tested was useful for the discrimination of malignant from benign effusions. However, measurement of pericardial CA 72-4 levels in bloody pericardial effusions yielded a high diagnostic accuracy and thus offers the potential as a diagnostic tool to distinguish between malignant and benign effusions.

To evaluate accuracy of mid-forehead (MFH) thermometry compared with digital axilla (DAT) temperatures in infants in newborn intensive care. A comparative study of MFH and DAT temperatures of newborn infants receiving tertiary-level intensive care. All admissions were considered and the following exclusion criteria applied: ‘in extremis’, hypoxic ischemic encephalopathy or non-English-speaking parents. Foot temperatures, infant and environmental variables were measured. In all, 783 readings were obtained in 100 infants with a birth weight range 515 to 4885 g (mean 2152 g). The between-person correlation was 0.30 (P

Alzheimer’s disease (AD) is the primary cause of dementia in the elderly. The ectodomain of p75 neurotrophin receptor (p75NTR-ECD) has been suggested to play important roles in regulating beta-amyloid (Aβ) deposition and in protecting neurons from the toxicity of soluble Aβ. However, whether and how the serum and cerebrospinal fluid (CSF) levels of p75NTR-ECD change in patients with AD are not well documented. In the present study, we determined the concentrations of serum p75NTR-ECD in an AD group, a Parkinson disease group and a stroke group, as well as in a group of elderly controls without neurological disorders (EC). We also determined the levels of CSF p75NTR-ECD in a subset of the AD and EC groups. Our data showed that a distinct p75NTR-ECD profile characterized by a decreased CSF level and an increased serum level was present concomitantly with AD patients but not with other diseases. p75NTR-ECD levels in both the serum and CSF were strongly correlated with Mini-Mental State Examination (MMSE) scores and showed sound differential diagnostic value for AD. Moreover, when combining CSF Aβ42, CSF Aβ42/40, CSF ptau181 or CSF ptau181/Aβ42 with CSF p75NTR-ECD, the area under the receiver operating characteristic curve (AUC) and diagnostic accuracies improved. These findings indicate that p75NTR-ECD can serve as a specific biomarker for AD and the determination of serum and CSF p75NTR-ECD levels is likely to be helpful in monitoring AD progression.