Low Intraobserver Variability Research Articles

Incorporating Sperm DNA Fragmentation Index with Computer-Assisted Semen Morphokinematic Parameters as a Better Window to Male Fertility

This study aimed to assess (1) the reproducibility of three sperm chromatin dispersion (SCD) assays for sperm DNA fragmentation, i.e., LensHooke R10® (R10), Halosperm G2® (G2), and BASO® (BA); (2) the correlation between computer-assisted semen analyzer (CASA) morphokinematic parameters and sperm DNA fragmentation index (DFI), and (3) the diagnostic value for male reproduction by combining semen morphokinematic parameters and DFI. Total 50 male participants were recruited, and all collected semen samples underwent semen analyses and SCD assays. Intra- and inter-observer variability of DFI data from different SCD measures was tested. In addition, the predictive ability of CASA parameters and DFI (with different cutoffs, i.e., 15% and 20%) for infertility was assessed using receiver operating characteristic curve analysis. We found that the G2 and R10 produced satisfactory variance coefficients (5.53%, 5.67%) compared to BA (14.8%). The DFI data from the R10 had lower intra-observer variability, in terms of higher intra-class coefficient (0.9615), than that of the G2 (0.8847) or BA (0.8824). Inter-observer variability of three SCD kits in scoring the DFI was comparable and satisfactory (concordance correlation coefficients ranging 0.9895-0.9630). The CASA parameters (i.e., total motility [r = -0.57], progression motility [r = -0.55], and rapidly progressive motility [r = -0.55]) were significantly correlated with DFI (P < 0.001). The predictive ability of the 15%-cutoff DFI data was better than that of the 20%-cutoff or continuous DFI data. The model comprising the CASA parameters, 15%-cutoff DFI, and 4%-cutoff normal morphology had the highest area under curve (0.8125) for infertility. For SCD assay, the R10 was the most reliable SCD assay to detect sperm DNA fragmentation. Combining the sperm DFI with CASA parameters might be a better diagnostic tool for male reproduction.

Velocity encoded mitral valve inflow cine: A novel and more reproducible method to determine cardiac rest periods during coronary magnetic resonance angiography.

A high temporal resolution, 4-chamber (4CH) cine is the standard method for determining cardiac rest periods during whole heart coronary magnetic resonance angiography (CMRA). We evaluated the image quality and reproducibility between the 4CH cine method and a novel approach using a velocity encoded mitral valve inflow cine (MVI). The goal of this study was to compare the quality of CMRAs utilizing MVI versus 4CH methods. Sharpness and vessel length for the LCA and RCA using each method were determined using Soap Bubble and two blinded observers independently assessed coronary image quality. Offline analysis on a separate, retrospective cohort (n = 25) was used to compare MVI and 4CH reproducibility. In the prospectively evaluated cohort there was no difference in overall vessel sharpness (4CH vs MVI mean ± SD) (31.0 ± 5.5% vs 30.5 ± 5.7%, p = .63), LCA vessel sharpness (30.0 ± 5.4% vs 31.1 ± 8.2%, p = .44), LCA length (4.7 ± 1.4 cm vs 4.6 ± 1.6 cm, p = .66), RCA vessel sharpness (32.1 ± 6.9% vs 31.1 ± 7.7%, p = .55), RCA length (5.51 ± 2.6 cm vs 5.95 ± 2.4 cm, p = .38), or image quality rating (2.66 vs 2.62, p = .80) between methods. In the retrospective cohort, the MVI method had 5.4% lower inter-observer variability (95% CI 3.7,7.2%, p < .0001) and 3.9% lower intra-observer variability (95% CI 2.4,5.4%, p < .0001) than the 4CH method.MVI is a technically feasible and more reproducible method to determine cardiac rest periods compared to 4CH while preserving vessel sharpness, vessel length & image quality.

Comparison of response assessment in veterinary neuro-oncology and two volumetric neuroimaging methods to assess therapeutic brain tumour responses in veterinary patients.

Standardized veterinary neuroimaging response assessment methods for brain tumours are lacking. Consequently, a response assessment in veterinary neuro-oncology (RAVNO) system which uses the sum product of orthogonal lesion diameters on 1-image section with the largest tumour area, has recently been proposed. In this retrospective study, 22 pre-treatment magnetic resonance imaging (MRI) studies from 18 dogs and four cats with suspected intracranial neoplasia were compared by a single observer to 32 post-treatment MRIs using the RAVNO system and two volumetric methods based on tumour margin or area delineation with HOROS and 3D Slicer software, respectively. Intra-observer variability was low, with no statistically significant differences in agreement index between methods (mean AI ± SD, 0.91 ± 0.06 for RAVNO; 0.86 ± 0.08 for HOROS; and 0.91 ± 0.05 for 3D slicer), indicating good reproducibility. Response assessments consisting of complete or partial responses, and stable or progressive disease, agreed in 23 out of 32 (72%) MRI evaluations using the three methods. The RAVNO system failed to identify changes in mass burden detected with volumetric methods in six cases. 3D Slicer differed from the other two methods in three cases involving cysts or necrotic tissue as it allowed for more accurate exclusion of these structures. The volumetric response assessment methods were more precise in determining changes in absolute tumour burden than RAVNO but were more time-consuming to use. Based on observed agreement between methods, low intra-observer variability and decreased time constraint, RAVNO might be a suitable response assessment method for the clinical setting.

Repeatability and reproducibility of deep-learning-based liver volume and Couinaud segment volume measurement tool

PurposeVolumetric and health assessment of the liver is crucial to avoid poor post-operative outcomes following liver resection surgery. No current methods allow for concurrent and accurate measurement of both Couinaud segmental volumes for future liver remnant estimation and liver health using non-invasive imaging. In this study, we demonstrate the accuracy and precision of segmental volume measurements using new medical software, Hepatica™.MethodsMRI scans from 48 volunteers from three previous studies were used in this analysis. Measurements obtained from Hepatica™ were compared with OsiriX. Time required per case with each software was also compared. The performance of technicians and experienced radiologists as well as the repeatability and reproducibility were compared using Bland–Altman plots and limits of agreement.ResultsHigh levels of agreement and lower inter-operator variability for liver volume measurements were shown between Hepatica™ and existing methods for liver volumetry (mean Dice score 0.947 ± 0.010). A high consistency between technicians and experienced radiologists using the device for volumetry was shown (± 3.5% of total liver volume) as well as low inter-observer and intra-observer variability. Tight limits of agreement were shown between repeated Couinaud segment volume (+ 3.4% of whole liver), segmental liver fibroinflammation and segmental liver fat measurements in the same participant on the same scanner and between different scanners. An underestimation of whole-liver volume was observed between three non-reference scanners.ConclusionHepatica™ produces accurate and precise whole-liver and Couinaud segment volume and liver tissue characteristic measurements. Measurements are consistent between trained technicians and experienced radiologists.Graphic abstract

Right Ventricular Global and Regional Remodeling in American-Style Football Athletes: A Longitudinal 3D Echocardiographic Study

Few data exist concerning the right ventricular (RV) physiological adaptation in American-style football (ASF) athletes. We aimed to analyze the RV global and regional responses among ASF-trained athletes. Fifty-nine (20 linemen and 39 non-linemen) ASF athletes were studied before and after inter-seasonal training. During this period, which lasted 7 months, all athletes were exposed to combined dynamic and static exercises. Cardiac longitudinal changes were examined using three-dimensional transthoracic echocardiography. A computational method based on geodesic distances was applied to volumetrically parcellate the RV into apical, outlet, and inlet regions. RV global and regional end-diastolic volumes increased significantly and similarly in linemen and non-linemen after training, with predominant changes in the apex and outlet regions. RV global and regional ejection fractions were preserved. Morphological changes were uniformly distributed among the four cardiac chambers, and it was independent of the field position. Assessment of RV end-diastolic global, inlet and apical volumes showed low intra-observer (3.3%, 4.1%, and 5.3%, respectively) and inter-observer (7%, 12.2%, and 9%, respectively) variability, whereas the outlet regional volumetric assessment was less reproducible. To conclude, ASF inter-seasonal training was associated with a proportionate biventricular enlargement, regardless of the field position. Regional RV analysis allowed us to quantify the amount of exercise-induced remodeling that was larger in the apical and outlet regions.

Left Ventricular Blood Flow Kinetic Energy Assessment by 4D Flow Cardiovascular Magnetic Resonance: A Systematic Review of the Clinical Relevance.

Background: There is an emerging body of evidence that supports the potential clinical value of left ventricular (LV) intracavity blood flow kinetic energy (KE) assessment using four-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR). The aim of this systematic review is to summarize studies evaluating LV intracavity blood flow KE quantification methods and its potential clinical significance. Methods: A systematic review search was carried out on Medline, Pubmed, EMBASE and CINAHL. Results: Of the 677 articles screened, 16 studies met eligibility. These included six (37%) studies on LV diastolic function, another six (37%) studies on heart failure or cardiomyopathies, three (19%) studies on ischemic heart disease or myocardial infarction and finally, one (6%) study on valvular heart disease, namely, mitral regurgitation. One of the main strengths identified by these studies is high reproducibility of LV blood flow KE hemodynamic assessment (mean coefficient of variability = 6 ± 2%) for the evaluation of LV diastolic function. Conclusions: The evidence gathered in this systematic review suggests that LV blood flow KE has great promise for LV hemodynamic assessment. Studies showed increased diagnostic confidence at no cost of additional time. Results were highly reproducible with low intraobserver variability.

Development and validation of a robust patellar reference coordinate system for biomechanical and clinical studies

BackgroundThis study aimed to develop and validate a reference coordinate system for the human patella, based on the registration of bony landmarks on a computed tomography (CT) scan. MethodsThirty-three native cadaveric specimens were scanned, and an observer marked a set of seven anatomical landmarks on each of them. Such markers were used to define the reference coordinate system. In order to validate its robustness, statistical distribution of the point registration was then studied. Afterwards, three different observers marked the anatomical landmarks on a sub-sample of six specimens and the intra-observer and inter-observer variability of the point registration was performed. ResultsResults of this study showed the highest values to be 1.46 mm (intra) and 4.08 mm (inter), both observed for the patellar ridge top. The intra-class correlation coefficient (ICC) for inter-observer variability ranked higher than 0.8 for all the landmarks used for the identification of the reference frame, and ranged from 0.4–0.9 for other landmarks. ConclusionsThis study demonstrates low intra-observer and inter-observer variability in the CT registration of landmarks that define and validate a robust coordinate system of the patella that could be used to perform accurate biomechanical and clinical studies.

Impact of 90Y PET gradient-based tumor segmentation on voxel-level dosimetry in liver radioembolization

BackgroundThe purpose was to validate 90Y PET gradient-based tumor segmentation in phantoms and to evaluate the impact of the segmentation method on reported tumor absorbed dose (AD) and biological effective dose (BED) in 90Y microsphere radioembolization (RE) patients. A semi-automated gradient-based method was applied to phantoms and patient tumors on the 90Y PET with the initial bounding volume for gradient detection determined from a registered diagnostic CT or MR; this PET-based segmentation (PS) was compared with radiologist-defined morphologic segmentation (MS) on CT or MRI. AD and BED volume histogram metrics (D90, D70, mean) were calculated using both segmentations and concordance/correlations were investigated. Spatial concordance was assessed using Dice similarity coefficient (DSC) and mean distance to agreement (MDA). PS was repeated to assess intra-observer variability.ResultsIn phantoms, PS demonstrated high accuracy in lesion volumes (within 15%), AD metrics (within 11%), high spatial concordance relative to morphologic segmentation (DSC > 0.86 and MDA < 1.5 mm), and low intra-observer variability (DSC > 0.99, MDA < 0.2 mm, AD/BED metrics within 2%). For patients (58 lesions), spatial concordance between PS and MS was degraded compared to in-phantom (average DSC = 0.54, average MDA = 4.8 mm); the average mean tumor AD was 226 ± 153 and 197 ± 138 Gy, respectively for PS and MS. For patient AD metrics, the best Pearson correlation (r) and concordance correlation coefficient (ccc) between segmentation methods was found for mean AD (r = 0.94, ccc = 0.92), but worsened as the metric approached the minimum dose (for D90, r = 0.77, ccc = 0.69); BED metrics exhibited a similar trend. Patient PS showed low intra-observer variability (average DSC = 0.81, average MDA = 2.2 mm, average AD/BED metrics within 3.0%).Conclusions90Y PET gradient-based segmentation led to accurate/robust results in phantoms, and showed high concordance with MS for reporting mean tumor AD/BED in patients. However, tumor coverage metrics such as D90 exhibited worse concordance between segmentation methods, highlighting the need to standardize segmentation methods when reporting AD/BED metrics from post-therapy 90Y PET. Estimated differences in reported AD/BED metrics due to segmentation method will be useful for interpreting RE dosimetry results in the literature including tumor response data.

Three-dimensional assessment of lower limb alignment: Accuracy and reliability

IntroductionThree-dimensional (3D) surgical planning and patient-specific implants are becoming increasingly popular in orthopedics and trauma surgery. In contrast to the established and standardized alignment assessment on two-dimensional (2D) long standing radiographs (LSRs) there is neither a standardized nor a validated protocol for the analysis of 3D bone models of the lower limb. This study aimed to create a prerequisite for pre-operative planning. MethodsAccording to 2D analysis and after meticulous research, 24 landmarks were defined on 3D bone models obtained from computed axial tomography (CT) scans for a 3D alignment assessment. Three observers with different experience levels performed the test three different times on three specimens. Intraobserver and interobserver variability of the landmarks and the intraclass correlation coefficient (ICC) of the resulting axes and joint angles were evaluated. ResultsOverall, the intraobserver and interobserver variability was low, with a mean deviation <5 mm for all landmarks. The ICC of all joint angles and axis deviations was >0.8, except for tibial torsion (ICC = 0.69). All knee joint angles showed excellent ICC (>0.95). ConclusionsUsing the defined landmarks, a standardized 3D alignment assessment with low intraobserver and interobserver variability and high ICC values for the knee joint angles can be performed regardless of examiner's experience. The described method serves as a reliable standardized protocol for a 3D malalignment test of the lower limb. Three-dimensional pre-operative analysis might enhance understanding of deformities and lead to a new focus in surgical planning.

Intraobserver and interobserver variability in first-trimester transvaginal ultrasound cervical length

Objectives: To determine intraobserver and interobserver variability in the measurement of different cervical length (CL) components at the first trimester (endocervical canal and isthmus), describe the optimum measurement method (single line or two lines) and establish a normality curve of first trimester CL in our population.Methods: Women who attended the first-trimester US scan, between 11.0 and 13.6 weeks of gestation at Vall d’Hebron Universitary Hospital, Barcelona, Spain were included. Inclusion criteria were singleton pregnancies in women over 18 years of age, no gestational complications, uterine malformations or uterine surgery. Lengths of the endocervical canal and uterine isthmus were measured using two methods.Results: Both methods for endocervical canal measurement, single line and two lines, showed low intraobserver variability between examiners, with no statistical differences in the majority of measurements. A correct correlation existed between examiners using the single-line two-line measurements, with a concordance correlation coefficient of 0.76.Conclusions: Cervical length in the first trimester was reproducible for the same physician and between different physicians; however, it is essential to ensure examiners receive adequate training in the technique.

Assessment of diastolic function and atrial remodeling byMRI - validation and correlation with echocardiography and filling pressure.

Atrial fibrosis can be estimated noninvasively by magnetic resonance imaging (MRI) using late gadolinium enhancement (LGE), but diastolic dysfunction is clinically assessed by transthoracic echocardiography (TTE), and rarely by MRI. This study aimed to evaluate well‐established diastolic parameters using MRI, and validate them with TTE and left ventricular (LV) filling pressures, and to study the relationship between left atrial (LA) remodeling and parameters of diastolic function. The study retrospectively included 105 patients (53 ± 16 years, 39 females) who underwent 3D LGE MRI between 2012 and 2016. Medical charts were reviewed for the echocardiographic diastolic parameters E, A, and e′ by TTE, and pressure catheterizations. E and A were measured from in‐plane phase‐contrast cardiac MRI images, and e′ by feature‐tracking, and validated with TTE. Interobserver and intraobserver variability was examined. Furthermore, LA volumes, function, and atrial LGE was correlated with diastolic parameters. Evaluation of e′ in MRI had strong agreement with TTE (r = 0.75, P < 0.0001), and low interobserver and intraobserver variability. E and A by TTE showed strong agreement to MRI (r = 0.77, P = 0.001; r = 0.73, P = 0.003, for E and A, respectively). Agreement between E/e′ by TTE and MRI was strong (r = 0.85, P = 0.0004), and E/e′ by TTE correlated moderately to invasive pressures (r = 0.59, P = 0.03). There was a strong relationship between LA LGE and pulmonary capillary wedge pressure (r = 0.81, P = 0.01). In conclusion, diastolic parameters can be measured with good reproducibility by cardiovascular MRI. LA LGE exhibited a strong relationship with pulmonary capillary wedge pressure, an indicator of diastolic function.

Validation of Quantitative 3-Dimensional Transesophageal Echocardiography Mitral Valve Analysis Using Stereoscopic Display

The use of 3-dimensional (3D) transesophageal echocardiography (TEE) in perioperative evaluation of the mitral valve (MV) is increasing progressively, including the use of 3D MV models for quantitative analysis. However, the use of 3D MV models in clinical practice still is limited by the need for specific training and the long time required for analysis. A new stereoscopic visualization tool (EchoPixel True 3D) allows virtual examination of anatomic structures in the clinical setting, but its accuracy and feasibility for intraoperative use is unknown. The aim of this study was to assess the feasibility of 3D holographic display and evaluate 3D quantitative measurements on a volumetric MV image using the EchoPixel system compared with the 3D MV model generated by QLAB Mitral Valve Navigation (MVN) software. This was a retrospective comparative study. The study took place in a tertiary care center. A total of 40 patients, 20 with severe mitral regurgitation who underwent mitral valve repair and 20 controls with normal MV, were enrolled retrospectively. The 3D-TEE datasets of the MV were analyzed using a 3D MV model and stereoscopic display. The agreement of measurements, intraobserver and interobserver variability, and time for analysis were assessed. Fair agreement between the 2 software systems was found for annular circumference and area in pathologic valves, but good agreement was reported for prolapse height and linear annular diameters. A higher agreement for all annular parameters and prolapse height was seen in normal valves. Excellent intraobserver and interobserver reliability was proved for the same parameters; time for analysis between the 2 methods in pathologic valves was substantially equivalent, although longer in pathologic valves when compared with normal MV using both tools. EchoPixel proved to be reliable to display 3D TEE datasets and accurate for direct linear measurement of both MV annular sizes and prolapse height compared to QLAB MVN software; it also carries a low interobserver and intraobserver variability for most measurements.

Interobserver and intraobserver variability in measuring the tortuosity of the thoracic aorta on computed tomography

ObjectiveThe variability in measuring the tortuosity of the thoracic aorta has not been previously studied. This study evaluated the interobserver and intraobserver variability of major methods used for measuring the tortuosity of the thoracic aorta in patients with aortic arch or descending thoracic aortic aneurysm. MethodsThis retrospective study enrolled 66 patients with aortic arch or descending thoracic aortic aneurysm who had undergone thoracic endovascular aortic repair. Two radiologists used preoperative computed tomography images to measure the tortuosity of the thoracic aorta at multiple segments by using the fitting circle diameter, tortuosity index, and centerline angle methods; these measurements were repeated after an interval of >28 days. The variability of the methods was analyzed for interobserver and intraobserver reliability and agreement. The estimated intraclass correlation coefficient (ICC) was used to analyze the reliability. The Bland-Altman plot was used to analyze the interobserver and intraobserver agreement. The association between aortic characteristics, including calcification, luminal irregularity, shape, and diameter, and the variability of the measurements was also analyzed. ResultsThe interobserver ICC estimates for the tortuosity index at multiple aortic segments, centerline angle methods at the supra-aortic branch orifices, and fitting circle diameter on the greater and lesser curvature sides were 0.97 to 0.98, 0.39 to 0.75, and 0.82 to 0.84, respectively. The corresponding intraobserver ICC estimates were 0.98 to 1.00, 0.44 to 0.75, and 0.82 to 0.85, respectively. In the agreement analysis, the 95% limits of agreement for the tortuosity index, centerline angle, and fitting circle diameter were −5.5% to 5.6%, −10.9% to 10.9%, and −18.0% to 24.0%, respectively. The tortuosity index had the highest ICC estimate and narrowest 99.5% limits of agreement of the three methods. Aortic characteristics, including calcification, grade of atheroma, aneurysm shape, and diameter, were not associated with the variability of the tortuosity index method in the thoracic aorta. ConclusionsThe tortuosity index method has low interobserver and intraobserver variability in measuring the tortuosity of the thoracic aorta in patients with thoracic aortic aneurysm. The characteristics of the aorta and aneurysm are not associated with the interobserver or intraobserver variability of the tortuosity index.

Renal Cell Carcinoma Perfusion before and after Radiofrequency Ablation Measured with Dynamic Contrast Enhanced MRI: A Pilot Study.

Aim: To investigate if the early treatment effects of radiofrequency ablation (RFA) on renal cell carcinoma (RCC) can be detected with dynamic contrast enhanced (DCE)-MRI and to correlate RCC perfusion with RFA treatment time. Materials and methods: 20 patients undergoing RFA of their 21 RCCs were evaluated with DCE-MRI before and at one month after RFA treatment. Perfusion was estimated using the maximum slope technique at two independent sittings. Total RCC blood flow was correlated with total RFA treatment time, tumour location, size and histology. Results: DCE-MRI examinations were successfully evaluated for 21 RCCs (size from 1.3 to 4 cm). Perfusion of the RCCs decreased significantly (p < 0.0001) from a mean of 203 (±80) mL/min/100 mL before RFA to 8.1 (±3.1) mL/min/100 mL after RFA with low intra-observer variability (r ≥ 0.99, p < 0.0001). There was an excellent correlation (r = 0.95) between time to complete ablation and pre-treatment total RCC blood flow. Tumours with an exophytic location exhibit the lowest mean RFA treatment time. Conclusion: DCE-MRI can detect early treatment effects by measuring RCC perfusion before and after RFA. Perfusion significantly decreases in the zone of ablation, suggesting that it may be useful for the assessment of treatment efficacy. Pre-RFA RCC blood flow may be used to predict RFA treatment time.

The effect of initial teaching on evaluation of left ventricular volumes by cardiovascular magnetic resonance imaging: comparison between complete and intermediate beginners and experienced observers

BackgroundHigh reproducibility and low intra- and interobserver variability are important strengths of cardiac magnetic resonance (CMR). In clinical practice a significant learning curve may however be observed. Basic CMR courses offer an average of 1.4 h dedicated to lecturing and demonstrating left ventricular (LV) function analysis. The purpose of this study was to evaluate the effect of initial teaching on complete and intermediate beginners’ quantitative measurements of LV volumes and function by CMR.MethodsStandard clinical cine CMR sequences were acquired in 15 patients. Five observers (two complete beginners, one intermediate, two experienced) measured LV volumes. Before initial evaluation beginners read the SCMR guidelines on CMR analysis. After initial evaluation, beginners participated in a two-hour teaching session including cases and hands-on training, representative for most basic CMR courses, after which it is uncertain to what extent different centres provide continued teaching and feedback in-house. Dice Similarity Coefficient (DSC) assessed delineations. Agreement, accuracy, precision, repeatability and reliability were assessed by Bland-Altman, coefficient of variation, and intraclass correlation coefficient methods.ResultsEndocardial DSC improved after teaching (+0.14 ± 0.17;p < 0.001) for complete beginners. Low intraobserver variability was found before and after teaching, however with wide limits of agreement. Beginners underestimated volumes by up to 44 ml (EDV), 27 ml (ESV) and overestimated LVM by up to 53 g before teaching, improving to an underestimation of up to 9 ml (EDV), 7 ml (ESV) and an overestimation of up to 30 g (LVM) after teaching. For the intermediate beginner, however, accuracy was quite high already before teaching.ConclusionsInitial teaching to complete beginners increases accuracy for assessment of LV volumes, however with high bias and low precision even after standardised teaching as offered in most basic CMR courses. Even though the intermediate beginner showed quite high accuracy already before teaching, precision did generally not improve after standardised teaching. To maintain CMR as a technique known for high accuracy and reproducibility and low intra- and inter-observer variability for quantitative measurements, internationally standardised training should be encouraged including high-quality feedback mechanisms. Objective measurements of training methods, training duration and, above all, quality of assessments are required.

Investigation of the variability of anterior chamber scan protocol with Cirrus high definition optical coherence tomography.

The evaluation of anterior chamber scan of Cirrus optical coherence tomography for routine clinical use. To assess the variability of anterior chamber angle measurements. This was a cross-sectional study. Forty subjects aged 40-80years were included. One randomly selected eye from 40 subjects was imaged with Cirrus optical coherence tomography (Carl Zeiss Meditec, Dublin, CA) by two different operators (expert vs. non-expert) with a 15-min interval for inter-observer and intra-observer variability of image acquisition. For image grading, the angle opening distance (AOD750) and the trabecular iris space area (TISA750) of nasal and temporal quadrants were measured with a customized algorithm (ImageJ, NIH, Bethesda, MD) by two different graders in a masked and random fashion. Bland Altman analysis and intraclass correlation coefficient (ICC) were calculated. ICC and limit of agreements (LOA). There were 15 (37.5%) eyes with closed angles. For inter-observer variability, the mean difference (95% LOA) of AOD750 for image acquisition and grading were -0.0039mm (-0.0486, 0.0408) and 0.0011mm (-0.0228, 0.025), respectively. The mean difference (95% LOA) of AOD750 for intra-observer variability for image acquisition and grading were 0.0013mm (-0.0362, 0.0389) and -0.0013mm (-0.0482, 0.0457), respectively. The ICCs were all ≥0.9. There was no significant difference in measurement variability between open and closed angles (P>0.05). Anterior chamber scan had low inter-observer and intra-observer variability in quantitative evaluation that was not affected by the angle status or the experience of an operator.

Evaluation of Intra- and Inter-observer Measurement Variability of a Radiographic Stifle Osteoarthritis Scoring System in Dogs.

Objectives To evaluate the intra- and inter-observer measurement variability of an existing osteoarthritis (OA) stifle scoring system. Methods Paired caudocranial and mediolateral canine stifle radiographs were selected randomly. A total of 15 assessment points were evaluated independently and graded twice (integer numeric scale: 1-4) at an interval of 2 weeks by three observers with different levels of experience. The grades for each of the 15 factors were summed to obtain the OA score for each patient. Results The 15 independent assessment points measured by the three observers showed high reproducibility and low intra-observer variability. Inter-observer variability was also low (mean: 1.09 ± 4.99, 95% CI [confidence interval]: -0.35 to 2.55). The most discordant ratings among the three observers involved sesamoid bones of gastrocnemius muscle (assessment point 11 of 15) and popliteal surface of femur (assessment point 10 of 15). Clinical Significance A validated and feasible OA scoring method is prerequisite for reliable radiographic assessment of OA progression. The low overall inter- and intra-observer variabilities among the 15 independent measures of the OA scoring system presented herein support its feasibility for application in clinical practice as an objective tool for radiographic scoring of stifle OA.

119 Proposal of a new technique for evaluating the total liver blood flow volume during pregnancy by doppler sonography

Introduction Estimation of the total liver blood flow volume by Doppler sonography during pregnancy might be a promising tool in the assessment of patients with severe PE/HELLP syndrome. The usual Doppler technique does not individual variations in vessel’s diameter. We believe this can be an important source of measurement bias. Objective To propose an improvement in the Doppler technique for evaluation of hepatic total blood flow during pregnancy. Method 55 normal pregnant women were included and signed informed consent. They were fasting for at least 6 h. The standard Doppler method of estimating flow volume does not consider variations in vessel’s diameter, the sample volume is set at 3,0 mm. We propose to measure the vessel’s diameter and to adjust the sample volume so that it occupies the entire vessel lumen. The volume flow should be calculated more accurately as the different speeds of the red blood cells are considered, instead of the speeds of the center of the vessel. Reproducibility was tested by interobserver and intraobserver variabilities. Two experienced examiners (A and B) performed all tests. Doppler sonography of the portal vein and the common hepatic artery were performed in the same woman three times by examiner A and three times by examiner B. Intraobserver variability was verified with the values obtained in the first and last measurements (supposed worst and best values). Variables analyzed were: portal vein (PV) flow volume A1 and A3, B1 and B3; common hepatic artery (CHA) flow volume A1 and A3, B1 and B3. Possible differences between the two observers were tested using the mean values obtained by each observer. We also calculated the intraclass correlation coefficient (ICC). Variables analyzed were: PV caliber A and B; CHA caliber A and B; Mean PV flow volume A and B; Mean CHA flow volume A and B. The statistical tests used for intra and interobserver variability testing were Stuart’s paired T-test, Pearson’s correlation coefficient and Blan–Altman’s plots of differences. Results Data was available for 50 women. We could not perform complete examination in 5 patients. Technical difficulties were mainly due to obesity, gas, and woman‘s intolerance to supine position. Women‘s mean age was 28y (18y–40y) and mean gestational age was 28w (20w–36w). We found low intraobserver and interobserver variability as demonstrated by paired T test and correlation coefficients in table 1. ICC for observer 1 was 0.982 for PV FV and 0.997 for CHA FV. ICC for observer 2 was 0.984 for PV FV and 0.998 for CHA FV. Conclusion The improvement we propose for Doppler assessment of the total hepatic blood flow in pregnancy has good intra and interobserver reproducibility. These results encourages us to continue research and to propose this method as preffered in pregnancy.

Validation of a Novel 3-Dimensional Sonographic Method for Assessing Gastric Accommodation in Healthy Adults.

A novel automated 3-dimensional (3D) sonographic method has been developed for measuring gastric volumes. This study aimed to validate and assess the reliability of this novel 3D sonographic method compared to the reference standard in 3D gastric sonography: freehand magneto-based 3D sonography. A prospective study with 8 balloons (in vitro) and 16 stomachs of healthy volunteers (in vivo) was performed. After a 500-mL liquid meal, 1 preprandial and 3 postprandial volume scans of the stomachs were performed by the novel 3D sonographic method and the current reference-standard 3D sonographic method. The in vitro study showed a mean volume difference between the novel method and the true balloon volume of -1.3 mL; limits of agreement (LoA) were small (-39.3 to12.3 mL), with an intraclass correlation coefficient (ICC) of 0.998. The in vivo study showed a mean gastric volume of 321 mL between the novel method and the freehand magneto-based method, with a mean volume difference of -4.4 mL; LoA were -40.1 to 31.2 mL, and the ICC was 0.991. The intraobserver and interobserver variability rates were low, at 0.8 mL (LoA, -24.0 to 25.6 mL), with an ICC of 0.995, and 0.5 mL (LoA, of -26.8 to 27.8 mL), with an ICC of 0.999, respectively. The novel 3D sonographic method with automated acquisition showed good agreement with the current reference-standard gastric 3D sonographic method, with low intraobserver and interobserver variability. This novel 3D sonographic method is a valid and reliable technique for determining gastric accommodation.

Probe-Based Confocal Laser Endomicroscopy of the Lungs

Probe-based confocal laser endomicroscopy (pCLE) is a relatively new technology in pulmonary medicine. Real time, in vivo visualization of elastin microstructure in the airway wall as well as alveoli is possible via flexible bronchoscopy under moderate sedation. This technique delivers high quality images without significant morbidity, and potentially enables non-invasive diagnosis. The images acquired have low intraobserver and intrapatient variability. The structure or normal airways and alveoli have already been elucidated. pCLE has been used in pilot studies for the diagnosis of various malignant lesions, airway diseases and diffuse parenchymal lung diseases. There may also be a role in monitoring of treatment response and disease progression. However, development is still needed both in the technology and standardization of endoscopic procedure to realize the full potential of pCLE.