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The knowledge of airway length is the theoretical basis in the diagnosis and management of airway disease. The objective of this study is to measure the length of trachea and left and right main bronchus in Chinese Shanghai population. A total of 153 consecutive adult patients with minor pulmonary disease in Xinhua hospital were enrolled for bronchoscopy examination. Measurements were conducted on head and neck neutral position and height, weight and age for each patient were recorded either. Student t test and multiple linear regression was used to compare means between males and females and to analyze correlation among height, weight, sexual dimorphism and the lengths of the trachea and bronchus. The lengths of the trachea and left main bronchus are significantly different between male and female patients (P

Introduction: Immunotherapy is being used for the past five years either as first line or second line treatment with great results. Chemotherapy and radiotherapy have been also used as combination to immunotherapy to further enhance this type of treatment. Intratumoral treatment has been previously proposed as a treatment option for certain non-small cell lung cancer patients. Patients and Methods: We recruited in total seventy four patients with non-small cell lung cancer in their second line treatment who received only chemotherapy in their first line treatment with programmed death-ligand-1 ≤ 50. Only adenocarcinoma or squamous cell carcinoma, and all negative for epidermal growth factor receptor, anaplastic lymphoma kinase, proto-oncogene tyrosine-protein kinase-1 and proto-oncogene B-Raf. Data were first examined with descriptive statistics choosing frequencies for categorical variables and histograms for the continuous ones. Twenty five received only intravenous immunotherapy and forty-nine intravenous cisplatin with immunotherapy. Data were first examined with descriptive statistics choosing frequencies for categorical variables and histograms for the continuous ones. Results: The relationships between changes of performance status and disease progression were examined via a single correspondence analysis. The two-dimensional scores (coordinates) derived from the correspondence analysis were then regressed against the predictors to form distinct splits and nodes obtaining quantitative results. The best fit is usually achieved by lowering exhaustively the AICc criterion and looking in parallel the change of R2 expecting improvements more than 5%. both types of therapy are capable of producing best ameliorative effects, when either the programmed death-ligand-1 expression or parenchymal site in joint with low pack years are present in the sampling data. Conclusions: Intratumoral treatment combination with cisplatin plus immunotherapy indifferent of nivolumab or pembrolizumab combination is an effective choice. In specific for those with endobronchial lesions. Moreover; patients with programmed death-ligand-1 ≥ 50 had their performance status and disease progression improved over the eight month observation.

Airway obstruction can be induced either by cancer or benign causes. Benign bronchus stenosis is being caused by: tuberculosis, sarcoidosis, vasculitis, and chronic inflammation due to smoking in c...

Objective: To investigate the development of bronchoscopy in China and compare it with its application in the early 21st century. Methods: The data collection was based on questionnaires. Three hundred and nineteen hospitals, which distributed across 30 provinces and 130 cities, were included in the study. Data about the application of bronchoscopy in Shanghai and Hunan province in the early 21st century are also involved for comparison. Results: The median period of performing diagnostic and therapeutic bronchoscopy was 19.7±11.0 and 7.4±7.0 years, respectively. On average, about 155.2 cases and 28.4 cases received diagnostic and therapeutic bronchoscopy in each hospital per month. The average area and number of the examination room was 122.7m2 and 2.2m2, respectively. More examination items were performed in specialty hospitals than those in general hospitals (P0.05). On the other side, the whole amount of diagnosis and therapeutic items in teaching hospitals was slightly higher than that in non-teaching hospitals (P

Background: Prostate cancer is considered to be highly sensitive to changes in radiation therapy dose per fraction, specifically to hypofractionation. An increase in the fractionation dose could cause a higher increase to the prostate than to the normal tissues leading to better disease control with less toxicity. Here we present the results of a randomized trial comparing mild hypofractionation to conventional fractionation after a median of 3,6 years follow up. Patients and Methods: 139 patients were randomized to receive either hypofractionated radiotherapy with 2,25 Gy/fr to a total of 72 Gy (arm 1) or conventionally fractionated treatment with 2Gy/fr to a total of 74 Gy (arm 2). 72 patients were assigned to arm 1 and 67 to arm 2. Results: After a median follow up of 3,6 years, 23 patients (31,9%) from arm 1 developed grade≥ 2 acute genitourinary toxicity and 21 (31,3%) from arm 2 (p=0,79). The corresponding values from gastrointestinal were 15 (20,8%) and 12 (17,9%) (p=0,6). For late toxicity from GU, 8 patients (11,1%) developed grade≥ 2 symptoms in arm 1 and 7 (10,4%) in arm 2 (p=0,92). late GI toxicity grade≥ 2 was observed in 8 (11,1%) patients in arm 1 and 8 (11,9%) in arm 2 (p=0,88). In multivariate analysis, hormone therapy was significantly associated with late GI events, while acute toxicity from both GU and GI was a prognostic factor of late adverse reaction. Conclusion: No difference in the toxicity profile could be identified between hypofractionation and conventional fractionation. Our schedule of 2,25Gy/fr seems safe and tolerable by the patients with acceptable rates of acute and late toxicity.

Background: Prostate cancer is considered to have a special biology which could affect the radiation therapy result based on the selected fractionation scheme. We present the preliminary results of a randomized trial comparing conventionally and hypofractionated radiation therapy for prostate cancer. Methods: Patients included in the study had localized prostate cancer (cT1c-T3bN0M0) and were randomly assigned to mild hypofractionated (72 Gy in 32 fractions, arm1) or conventionally fractionated (74 Gy in 37 fractions, arm2) radiation therapy treatment with Volumetric Arc Therapy technique. The treatment was delivered only to the prostate with or without the seminal vesicles according to physician's discretion and hormone therapy was optional according to the disease stage and comorbidities. Here we present the preliminary results of acute toxicity from the gastrointestinal (GI) and genitourinary (GU) system. Results: Between 2015 and 2016, 139 patients were enrolled. 67 patients were treated with conventional fractionation and 72 were treated with hypofractionation. Grade≥ 2 toxicity from GU and GI was observed in 23 and 21 patients (31,9% vs 31,3%, p=0,79) and 15 and 12 (20,8% vs 17,9%, p=0,6) for arm1 and arm2 respectively. No statistically significant differences were observed between arms in the incidence of early toxicity. There was no correlation observed between patient characteristics and toxicity from either GU or GI. Conclusions: Hypofractionated radiotherapy appears to be equally tolerated compared to conventional fractionation in the early setting. Longer follow up is needed to assess the late toxicity profile of the patients and any potential differences between the control and experimental arm.

Brain vascular damage accumulate in aging and often manifest as white matter hyperintensities (WMHs) on MRI. Despite increased interest in automated methods to segment WMHs, a gold standard has not been achieved and their longitudinal reproducibility has been poorly investigated. The aim of present work is to evaluate accuracy and reproducibility of two freely available segmentation algorithms. A harmonized MRI protocol was implemented in 3T-scanners across 13 European sites, each scanning five volunteers twice (test-retest) using 2D-FLAIR. Automated segmentation was performed using Lesion segmentation tool algorithms (LST): the Lesion growth algorithm (LGA) in SPM8 and 12 and the Lesion prediction algorithm (LPA). To assess reproducibility, we applied the LST longitudinal pipeline to the LGA and LPA outputs for both the test and retest scans. We evaluated volumetric and spatial accuracy comparing LGA and LPA with manual tracing, and for reproducibility the test versus retest. Median volume difference between automated WMH and manual segmentations (mL) was −0.22[IQR = 0.50] for LGA-SPM8, −0.12[0.57] for LGA-SPM12, −0.09[0.53] for LPA, while the spatial accuracy (Dice Coefficient) was 0.29[0.31], 0.33[0.26] and 0.41[0.23], respectively. The reproducibility analysis showed a median reproducibility error of 20%[IQR = 41] for LGA-SPM8, 14% [31] for LGA-SPM12 and 10% [27] with the LPA cross-sectional pipeline. Applying the LST longitudinal pipeline, the reproducibility errors were considerably reduced (LGA: 0%[IQR = 0], p < 0.001; LPA: 0% [3], p < 0.001) compared to those derived using the cross-sectional algorithms. The DC using the longitudinal pipeline was excellent (median = 1) for LGA [IQR = 0] and LPA [0.02]. LST algorithms showed moderate accuracy and good reproducibility. Therefore, it can be used as a reliable cross-sectional and longitudinal tool in multi-site studies.

Nowadays we have novel therapies for advanced stage non-small cell lung cancer. Immunotherapy has been introduced in the market for several years and until now its administration is mostly based on the programmed death-ligand 1. First line treatment with immunotherapy can be administered alone if programmed death-ligand 1 expression is ≥ 50%. All therapies for advanced stage disease have advantages and disadvantages, immunotherapy until now has presented mild adverse effects when compared to chemotherapy. However; it is known to induce inflammatory response to different tissues within the body. In our case acute pneumothorax was induced after immunotherapy administration.

Background: The amygdala and the hippocampus are two limbic structures that play a critical role in cognition and behavior, however their manual segmentation and that of their smaller nuclei/subfields in multicenter datasets is time consuming and difficult due to the low contrast of standard MRI. Here, we assessed the reliability of the automated segmentation of amygdalar nuclei and hippocampal subfields across sites and vendors using FreeSurfer in two independent cohorts of older and younger healthy adults.Methods: Sixty-five healthy older (cohort 1) and 68 younger subjects (cohort 2), from the PharmaCog and CoRR consortia, underwent repeated 3D-T1 MRI (interval 1-90 days). Segmentation was performed using FreeSurfer v6.0. Reliability was assessed using volume reproducibility error (epsilon) and spatial overlapping coefficient (DICE) between test and retest session.Results: Significant MRI site and vendor effects (p 0.43, p 0.80).Conclusion: Our results support the use of volumetric measures of larger amygdalar nuclei and hippocampal subfields in multisite MRI studies. These measures could be useful for disease tracking and assessment of efficacy in drug trials.

Background and objectives: During the last decade, conventional tobacco smoking is experiencing a decline and new smoking products have been introduced. IQOS (&ldquo, I-Quit-Ordinary-Smoking&rdquo, ) is a type of &ldquo, heat-not-burn&rdquo, (HNB) tobacco product. The impact of IQOS on respiratory health is currently not defined. The objectives of this study were to evaluate the acute effects of IQOS on pulmonary function in non-smokers and current smokers. Materials and Methods: Fifty male healthy non-smokers and current smokers with no known co-morbidity underwent an exhaled CO measurement, oximetry (SaO2%), pulmonary function tests (flows, volumes and diffusion capacity), and a measurement of respiratory resistances with an impulse oscillometry system (IOS) before and immediately after IQOS use. Results: In the whole group of 50 participants, SaO2%, forced expiratory flow at 25% and 50% of vital capacity (FEF25%, FEF50%, respectively), peak expiratory flow (PEF), and diffusion lung capacity for carbon monoxide/VA (KCO) decreased significantly after IQOS use, whereas exhaled CO and airway resistance (R5 Hz, R10 Hz, r15 Hz, R20 Hz, R25 Hz, R35 Hz) increased. When the groups of smokers and non-smokers were compared, in both groups (all males, 25 smokers and 25 non-smokers), exhaled CO increased and SaO2% decreased after IQOS use (p &lt, 0.001). In the group of non-smokers, PEF (pre 8.22 &plusmn, 2.06 vs. post 7.5 &plusmn, 2.16, p = 0.001) and FEF25% (pre 7.6 &plusmn, 1.89 vs. 7.14 &plusmn, 2.06, p = 0.009) decreased significantly, respiratory resistances R20 Hz (pre 0.34 &plusmn, 0.1 vs. post 0.36 &plusmn, 0.09, p = 0.09) and R25 Hz (pre 0.36 &plusmn, 0.1 vs. post 0.38 &plusmn, 0.09, p = 0.08) increased almost significantly. In smokers, PEF (pre 7.69 &plusmn, 2.26 vs. post 7.12 &plusmn, 2.03, p = 0.007) and expiratory reserve volume (ERV) (pre 1.57 &plusmn, 0.76 vs. post1.23 &plusmn, 0.48, p = 0.03) decreased and R35 Hz (pre 0.36 &plusmn, 0.11 vs. post 0.39 &plusmn, 0.11, p = 0.047) increased. The differences in the changes after the use of IQOS did not differ between groups. Conclusions: IQOS had an impact on exhaled CO, SaO2%, and airways function immediately after use. Even though these changes were rather small to be considered of major clinical importance, they should raise concerns regarding the long-term safety of this product. Further research is needed for the short- and long-term effects of IQOS, especially in patients with respiratory disease.

Introduction: Novel technologies are currently used for lung cancer diagnosis. EBUS-TBNA 22G is considered one of the most important tools. However; there are still issues with the sample size.Patients and Methods: 223 patients underwent EBUS-TBNA with a 21G Olympus needle, 22GUS Mediglobe and 22GUB Mediglobe. In order to evaluate the efficiency of 22GUB novel needle design. In order to evaluate the sample size of each needle, we constructed cell blocks and measured the different number of slices from each biopsy site. Results: The 22GUB novel needle had similar and larger number of slices from each biopsy site compared to 21G needle. Discussion: Firstly as a novel methodology we used the number of slices from the constructed cell blocks in order to evaluate the sample size. Secondly, we should seek novel needle designs and not only concentrate on the volume of the sample size.

Purpose: Diffusion Weighted Imaging is an established diagnostic tool for accurate differential diagnosis between benign and malignant liver lesions. The aim of our study was to evaluate the role of Histogram Analysis of ADC quantification in determining the histological diagnosis as well as the grade of malignant liver tumours. To our knowledge, there is no study evaluating the role of Histogram Analysis of ADC quantification in determining the histological diagnosis as well as the grade of malignant liver tumours. Methods: During five years, 115 patients with known liver lesions underwent Diffusion Weighted Imaging in 3Tesla MR scanner prior to core needle biopsy. Histogram analyses of ADC in regions of interest were drawn and were correlated with biopsy histological diagnosis and grading. Results: Histogram analysis of ADC values shows that 5th and 30th percentile parameters have statistically significant potency of discrimination between primary and secondary lesions groups (p values 0.0036 and 0.0125 respectively). Skewness of the histogram can help discriminate between good and poor differentiated (p value 0.17). Discrimination between primary malignancy site in metastases failed for the present number of patients in each subgroup. Conclusion: Statistical parameters reflecting the shape of the left side of the ADC histogram can be useful for discriminating between primary and secondary lesions and also between well differentiated versus moderate or poor. For the secondary malignancies, they failed to predict the original site of tumour.

3D printing is a rapidly advancing technology which represents a significant technological achievement that could be useful in a variety of biomedical applications. In the field of surgery, 3D printing is envisioned as a significant step in the areas of surgical planning, education and training. The 3D printed models are considered as high quality and efficient educational tools. In this paper A randomized controlled trial was performed to compare the educational role of 3D printed models with that of the conventional MRI films in the training of surgical residents. Statistical analysis revealed that Resident surgeons who studied only the anal fistula printed models, (Group B) achieved a higher overall score in the fistula assessment test (87,2 (82,6-91,6)) compared to resident surgeons (Group A) who studied only MRI images (74,85 (66,8-73,5)). 3D printing technology can lead to improvement in preoperative planning accuracy, followed by efficient optimization of the treatment strategy. It is believed that 3D printing technology could be used in the case of various other surgical applications, thus representing a novel tool for surgical education.

Wolfgang Hohenforst-Schmidt,1 Paul Zarogoulidis,2 Joshua Stopek,3 Thomas Vogl,4 Frank Hübner,1 J Francis Turner,5,6 Robert Browning,7 Konstantinos Zarogoulidis,2 Antonis Drevelegas,8 Konstantinos Drevelegas,8 Kaid Darwiche,9 Lutz Freitag,9 Harald Rittger101II Medical Clinic, Coburg Hospital, University of Wuerzburg, Coburg, Germany; 2Pulmonary Department-Oncology Unit, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 3Covidien, Jersey City, NJ, USA; 4Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Frankfurt, Germany; 5Division of Interventional Pulmonology, 6Medical Oncology, Cancer Treatment Centers of America, Western Regional Medical Center, Goodyear, AZ, 7Pulmonary and Critical Care Medicine, Interventional Pulmonology, National Naval Medical Center, Walter Reed Army Medical Center, Bethesda, MD, USA; 8Radiology Department, Interbalkan European Medical Center, Thessaloniki, Greece; 9Department of interventional Pneumology, Ruhrlandklinik, University Hospital Essen, University of Essen-Duisburg, Essen, Germany; 10Medical ClinicI, ‘Fuerth Hospital, University of Erlangen, Erlangen, GermanyAbstract: Lung cancer remains the leading cause of death in cancer patients. Severe treatment side effects and late stage of disease at diagnosis continue to be an issue. We investigated whether local treatment using 2-diethylaminoethyl-dextran methyl methacrylate copolymer with p53 (DDMC-p53) with or without cisplatin and/or microwave ablation enhances disease control in BALBC mice. We used a Lewis lung carcinoma cell line to inoculate 140 BALBC mice, which were divided into the following seven groups; control, cisplatin, microwave ablation, DDMC-p53, DDMC-p53 plus cisplatin, DDMC-p53 plus microwave, and DDMC-p53 plus cisplatin plus microwave. Microwave ablation energy was administered at 20 W for 10 minutes. Cisplatin was administered as 1 mL/mg and the DDMC-p53 complex delivered was 0.5 mL. Increased toxicity was observed in the group receiving DDMC-p53 plus cisplatin plus microwave followed by the group receiving DDMC-p53 plus cisplatin. Infection after repeated treatment administration was a major issue. We conclude that a combination of gene therapy using DDMC-p53 with or without cisplatin and microwave is an alternative method for local disease control. However, more experiments are required in a larger model to identify the appropriate dosage profile.Keywords: DDMC, p53, carboplatin, microwave, non-small cell lung cancer

Wolfgang Hohenforst-Schmidt,1 Paul Zarogoulidis,2 Joshua Stopek,3 Thomas Vogl,4 Frank Hübner,1 J Francis Turner,5,6 Robert Browning,7 Konstantinos Zarogoulidis,2 Antonis Drevelegas,8 Konstantinos Drevelegas,8 Kaid Darwiche,9 Lutz Freitag,9 Harald Rittger101II Medical Clinic, Coburg Hospital, University of Wuerzburg, Coburg, Germany; 2Pulmonary Department-Oncology Unit, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 3Covidien, Jersey City, NJ, USA; 4Department of Diagnostic and Interventional Radiology, Goethe University of Frankfurt, Frankfurt, Germany; 5Division of Interventional Pulmonology, 6Medical Oncology, Cancer Treatment Centers of America, Western Regional Medical Center, Goodyear, AZ, 7Pulmonary and Critical Care Medicine, Interventional Pulmonology, National Naval Medical Center, Walter Reed Army Medical Center, Bethesda, MD, USA; 8Radiology Department, Interbalkan European Medical Center, Thessaloniki, Greece; 9Department of interventional Pneumology, Ruhrlandklinik, University Hospital Essen, University of Essen-Duisburg, Essen, Germany; 10Medical ClinicI, ‘Fuerth Hospital, University of Erlangen, Erlangen, GermanyAbstract: Lung cancer remains the leading cause of death in cancer patients. Severe treatment side effects and late stage of disease at diagnosis continue to be an issue. We investigated whether local treatment using 2-diethylaminoethyl-dextran methyl methacrylate copolymer with p53 (DDMC-p53) with or without cisplatin and/or microwave ablation enhances disease control in BALBC mice. We used a Lewis lung carcinoma cell line to inoculate 140 BALBC mice, which were divided into the following seven groups; control, cisplatin, microwave ablation, DDMC-p53, DDMC-p53 plus cisplatin, DDMC-p53 plus microwave, and DDMC-p53 plus cisplatin plus microwave. Microwave ablation energy was administered at 20 W for 10 minutes. Cisplatin was administered as 1 mL/mg and the DDMC-p53 complex delivered was 0.5 mL. Increased toxicity was observed in the group receiving DDMC-p53 plus cisplatin plus microwave followed by the group receiving DDMC-p53 plus cisplatin. Infection after repeated treatment administration was a major issue. We conclude that a combination of gene therapy using DDMC-p53 with or without cisplatin and microwave is an alternative method for local disease control. However, more experiments are required in a larger model to identify the appropriate dosage profile.Keywords: DDMC, p53, carboplatin, microwave, non-small cell lung cancer

Bronchogenic cysts are rare congenital malformations which derive from primitive ventral foregut. They are usually observed in intrathoracically. A fifty year old male was admitted for the investigation of a three month chest pain. Computed tomography scan of the thorax revealed a lesion around the esophagus and left stem bronchus. Endobronchial ultrasound with convex probe and a 19G needle biopsy revealed a bronchogenic cystic which was removed with video assisted thoracic surgery. Initial radiologic assessment although was thought to be lung cancer because of the smoking habit it turned out to be benignancy. EBUS-TBNAB with 10G needle is safe and absolutely necessary for these lesions, as they take large samples.

Schwannomas are the commonest intradural extramedullary tumors of the spine, mostly present in the cervical and lumbar regions. Spinal schwannomas with intratumoral haemorrhage are very rare lesions. Authors here present a 40-year’s old male with a 2 year history of pain in the thoracic region and acute onset of spastic paraparesis and cauda equina syndrome. Magnetic Resonance Imaging (MRI) of his thoracic spine demonstrated a heterogeneous intradural extramedullary lesion with no associated enhancement. After emergent removal of the mass, histopathology revealed schwannoma with intratumoral haemorrhage.

Understanding how to reduce the influence of physiological noise in resting state fMRI data is important for the interpretation of functional brain connectivity. Limited data is currently available to assess the performance of physiological noise correction techniques, in particular when evaluating longitudinal changes in the default mode network (DMN) of healthy elderly participants. In this 3T harmonized multisite fMRI study, we investigated how different retrospective physiological noise correction (rPNC) methods influence the within-site test-retest reliability and the across-site reproducibility consistency of DMN-derived measurements across 13 MRI sites. Elderly participants were scanned twice at least a week apart (five participants per site). The rPNC methods were: none (NPC), Tissue-based regression, PESTICA and FSL-FIX. The DMN at the single subject level was robustly identified using ICA methods in all rPNC conditions. The methods significantly affected the mean z-scores and, albeit less markedly, the cluster-size in the DMN; in particular, FSL-FIX tended to increase the DMN z-scores compared to others. Within-site test-retest reliability was consistent across sites, with no differences across rPNC methods. The absolute percent errors were in the range of 5-11% for DMN z-scores and cluster-size reliability. DMN pattern overlap was in the range 60-65%. In particular, no rPNC method showed a significant reliability improvement relative to NPC. However, FSL-FIX and Tissue-based physiological correction methods showed both similar and significant improvements of reproducibility consistency across the consortium (ICC = 0.67) for the DMN z-scores relative to NPC. Overall these findings support the use of rPNC methods like tissue-based or FSL-FIX to characterize multisite longitudinal changes of intrinsic functional connectivity. Hum Brain Mapp 37:2114-2132, 2016. © 2016 Wiley Periodicals, Inc.

The most common histological types of invasive breast carcinomas are the invasive ductal carcinoma (IDC) and the invasive lobular carcinoma (ILC). The purpose of our study was to evaluate the role of the diffusion-weighted imaging (DWI) and the in vivo proton magnetic resonance spectroscopy (We retrospectively studied at 3Tesla magnet the apparent diffusion coefficient (ADC) values, the detection of choline in theThe ADC values in the 158 out of 160 IDC patients, ranged from 0.5 x 10Our results are consistent with previous findings that both ADC values and choline detection in the spectrum play a significant role in establishing the final diagnosis of malignancy, especially when the kinetic pattern of enhancement is misleading. Hippokratia 2016, 20(3): 192-197.

Recently, there has been an increased interest in the use of automatically segmented subfields of the human hippocampal formation derived from magnetic resonance imaging (MRI). However, little is known about the test-retest reproducibility of such measures, particularly in the context of multisite studies. Here, we report the reproducibility of automated Freesurfer hippocampal subfields segmentations in 65 healthy elderly enrolled in a consortium of 13 3T MRI sites (five subjects per site). Participants were scanned in two sessions (test and retest) at least one week apart. Each session included two anatomical 3D T1 MRI acquisitions harmonized in the consortium. We evaluated the test-retest reproducibility of subfields segmentation (i) to assess the effects of averaging two within-session T1 images and (ii) to compare subfields with whole hippocampus volume and spatial reliability. We found that within-session averaging of two T1 images significantly improved the reproducibility of all hippocampal subfields but not that of the whole hippocampus. Volumetric and spatial reproducibility across MRI sites were very good for the whole hippocampus, CA2-3, CA4-dentate gyrus (DG), subiculum (reproducibility error∼2% and DICE > 0.90), good for CA1 and presubiculum (reproducibility error ∼ 5% and DICE ∼ 0.90), and poorer for fimbria and hippocampal fissure (reproducibility error ∼ 15% and DICE

WOS:000390259700002; International audience; Free water elimination (FWE) in brain diffusion MRI has been shown to improve tissue specificity in human white matter characterization both in health and in disease. Relative to the classical diffusion tensor imaging (DTI) model, FWE is also expected to increase sensitivity to microstructural changes in longitudinal studies. However, it is not clear if these two models differ in their test-retest reproducibility. This study compares a bi-tensor model for FWE with DTI by extending a previous longitudinal-reproducibility 3T multisite study (10 sites, 7 different scanner models) of 50 healthy elderly participants (55-80 years old) scanned in two sessions at least 1 week apart. We computed the reproducibility of commonly used DTI metrics (FA: fractional anisotropy, MD: mean diffusivity, RD: radial diffusivity, and AXD: axial diffusivity), derived either using a DTI model or a FWE model. The DTI metrics were evaluated over 48 white-matter regions of the JHU-ICBM-DTI-81 white-matter labels atlas, and reproducibility errors were assessed. We found that relative to the DTI model, FWE significantly reduced reproducibility errors in most areas tested. In particular, for the FA and MD metrics, there was an average reduction of approximately 1% in the reproducibility error. The reproducibility scores did not significantly differ across sites. This study shows that FWE improves sensitivity and is thus promising for clinical applications, with the potential to identify more subtle changes. The increased reproducibility allows for smaller sample size or shorter trials in studies evaluating biomarkers of disease progression or treatment effects. Hum Brain Mapp 38:12-26, 2017. (c) 2016 Wiley Periodicals, Inc.