scholarly journals In vivo electrical conductivity measurement of muscle, cartilage, and peripheral nerve around knee joint using MR-electrical properties tomography

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji Hyun Lee ◽  
Young Cheol Yoon ◽  
Hyun Su Kim ◽  
Jiyeong Lee ◽  
Eunju Kim ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Knee Joint ◽  
Peripheral Nerve ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Conductivity Measurement ◽  
Post Exercise ◽  
Musculoskeletal Tissues

AbstractThis study aimed to investigate whether in vivo MR-electrical properties tomography (MR-EPT) is feasible in musculoskeletal tissues by evaluating the conductivity of muscle, cartilage, and peripheral nerve around the knee joint, and to explore whether these measurements change after exercise. This prospective study was approved by the institutional review board. On February 2020, ten healthy volunteers provided written informed consent and underwent MRI of the right knee using a three-dimensional balanced steady-state free precession (bSSFP) sequence. To test the effect of loading, the subjects performed 60 squatting exercises after baseline MRI, immediately followed by post-exercise MRI with the same sequences. After reconstruction of conductivity map based on the bSSFP sequence, conductivity of muscles, cartilages, and nerves were measured. Measurements between the baseline and post-exercise MRI were compared using the paired t-test. Test–retest reliability for baseline conductivity was evaluated using the intraclass correlation coefficient. The baseline and post-exercise conductivity values (mean ± standard deviation) [S/m] of muscles, cartilages, and nerves were 1.73 ± 0.40 and 1.82 ± 0.50 (p = 0.048), 2.29 ± 0.47 and 2.51 ± 0.37 (p = 0.006), and 2.35 ± 0.57 and 2.36 ± 0.57 (p = 0.927), respectively. Intraclass correlation coefficient for the baseline conductivity of muscles, cartilages, and nerves were 0.89, 0.67, and 0.89, respectively. In conclusion, in vivo conductivity measurement of musculoskeletal tissues is feasible using MR-EPT. Conductivity of muscles and cartilages significantly changed with an overall increase after exercise.

Prospective Trial on Probe-Based Confocal Laser Endomicroscopy for the Identification of the Distal Limit in Rectal Adenocarcinoma

2018 ◽  
Vol 25 (4) ◽  
pp. 313-322 ◽  
Author(s):  
Arthur R. Wijsmuller ◽  
Jean-Pierre Ghnassia ◽  
Sharmini Varatharajah ◽  
Mickael Schaeffer ◽  
Joel Leroy ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Sensitivity And Specificity ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Prospective Trial ◽  
Rectal Adenocarcinoma ◽  
Neoadjuvant Chemoradiation ◽  
Confocal Laser Endomicroscopy ◽  
Confocal Laser

Background. Intraoperative decision of the level of distal resection in rectal cancer is often imprecise, based exclusively on digital examination and pretherapeutic imaging. Design. Prospective, single institution, nonrandomized trial ( ClinicalTrial.gov identification no. NCT01887509) to evaluate the contribution of probe-based confocal laser endomicroscopy (pCLE) to establish the optimal resection margin of rectal adenocarcinoma. The primary outcome was the concordance in the identification of lower tumor margins between pCLE and histopathology. For each patient, pCLE examination was performed on nonneoplastic and neoplastic aspects of the distal tumor margin, before and after neoadjuvant chemoradiation, or preceding surgery, if chemoradiation was not required. Biopsies were taken at the same locations. The intraclass correlation coefficient was determined. Results. Twenty-one patients were enrolled. Thirteen patients completed the full study. Six patients completed imaging only before chemoradiation. Two patients retracted their consent after inclusion. A total of 134 videos and corresponding histopathology samplings were analyzed. The sensitivity and specificity of in vivo pCLE interpretation were 0.915 (95% confidence interval [CI] = 0.840-0.970) and 0.736 (95% CI = 0.657-0.821), respectively. The sensitivity and specificity of the blinded pCLE reinterpretation were 0.930 (95% CI = 0.858-0.980) and 0.688 (95% CI = 0.600-0.770), respectively. No deep layer tumor infiltration was encountered in the samplings with superficial healthy layers. The intraclass correlation coefficient for in vivo pCLE interpretation and blinded pCLE reinterpretation were 0.747 (95% CI = 0.257-0.993) and 0.766 (95% CI = 0.280-0.995), respectively. Conclusions. This supports the concordance between pCLE and histopathology in identifying the “tumor-free” limit of a rectal tumor preceding resection.

scholarly journals New Tracking System of Human Scapula Using Ultrasonography and Motion Sensors: A Descriptive Test–Retest Design

2019 ◽  
Vol 28 (7) ◽  
Author(s):  
Manuel Trinidad-Fernández ◽  
Manuel González-Sánchez ◽  
Antonio I. Cuesta-Vargas
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Ultrasound Imaging ◽  
Repeated Measures ◽  
External Rotation ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
New Method

Context: Several studies have shown that the kinematics of the scapula is altered in many disorders that affect the shoulder. Description of scapular motion in the chest continues to be a scientific and clinical challenge. Objective: To check the validity and reliability of a new, minimally invasive method of tracking the internal and external rotation of the scapula using ultrasound imaging combined with the signal provided by a 3-dimensional electromagnetic sensor. Design: A cross-sectional study with a repeated-measures descriptive test–retest design was employed to evaluate this new tracking method. The new method was validated in vitro and the reliability of data over repeated measures between scapula positions was calculated in vivo. Setting: University laboratory. Participants: A total of 30 healthy men and women. Main Outcome Measure: The validation of the scapula rotation tracking using the in vitro model was calculated by Pearson correlation test between a 2-dimensional cross-correlation algorithm of the new method and another software image. The reliability of the tracking of the scapula rotation was measured using the intraclass correlation coefficient. Results: In the validation in vitro, the correlation of rotations obtained by the 2 methods was good (r = .77, P = .01). The reliability in vivo had excellent results (intraclass correlation coefficient = .88; 95% confidence interval, .82–.93) in the test–retest analysis of 8 measures. The intrarater analysis of variance test showed no significant differences between the measures (P = .85, F = 0.46). Conclusion: Ultrasound imaging combined with a motion sensor to track the scapula has been shown to be a reliable and valid method for measuring internal and external rotation during separation of the upper limb.

scholarly journals Biomechanical Measurement of Rabbit Cornea by a Modified Scheimpflug Device

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Bo Zhang ◽  
Jianjun Gu ◽  
Xiaoxiao Zhang ◽  
Bin Yang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Bulk Modulus ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Intraobserver Reliability ◽  
Rabbit Cornea ◽  
Deformation Response ◽  
Biomechanical Measurements ◽  
Biomechanical Measurement

Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device.Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated.Results. All parameters showed good intraobserver reliability (Cronbach’s alpha; intraclass correlation coefficient,α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated.Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15–75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea.

scholarly journals A preliminary study of intensivist-performed DVT ultrasound screening in trauma ICU patients (APSIT Study)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lloyd Roberts ◽  
Tom Rozen ◽  
Deirdre Murphy ◽  
Adam Lawler ◽  
Mark Fitzgerald ◽  
...  
Keyword(s):  
Intensive Care ◽  
Deep Vein Thrombosis ◽  
High Risk ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Major Trauma ◽  
Intraclass Correlation ◽  
Trauma Patients ◽  
Vein Thrombosis ◽  
Deep Vein

Abstract Background Multiple screening Duplex ultrasound scans (DUS) are performed in trauma patients at high risk of deep vein thrombosis (DVT) in the intensive care unit (ICU). Intensive care physician performed compression ultrasound (IP-CUS) has shown promise as a diagnostic test for DVT in a non-trauma setting. Whether IP-CUS can be used as a screening test in trauma patients is unknown. Our study aimed to assess the agreement between IP-CUS and vascular sonographer performed DUS for proximal lower extremity deep vein thrombosis (PLEDVT) screening in high-risk trauma patients in ICU. Methods A prospective observational study was conducted at the ICU of Alfred Hospital, a major trauma center in Melbourne, Australia, between Feb and Nov 2015. All adult major trauma patients admitted with high risk for DVT were eligible for inclusion. IP-CUS was performed immediately before or after DUS for PLEDVT screening. The paired studies were repeated twice weekly until the DVT diagnosis, death or ICU discharge. Written informed consent from the patient, or person responsible, or procedural authorisation, was obtained. The individuals performing the scans were blinded to the others’ results. The agreement analysis was performed using Cohen’s Kappa statistics and intraclass correlation coefficient for repeated binary measurements. Results During the study period, 117 patients had 193 pairs of scans, and 45 (39%) patients had more than one pair of scans. The median age (IQR) was 47 (28–68) years with 77% males, mean (SD) injury severity score 27.5 (9.53), and a median (IQR) ICU length of stay 7 (3.2–11.6) days. There were 16 cases (13.6%) of PLEDVT with an incidence rate of 2.6 (1.6–4.2) cases per 100 patient-days in ICU. The overall agreement was 96.7% (95% CI 94.15–99.33). The Cohen’s Kappa between the IP-CUS and DUS was 0.77 (95% CI 0.59–0.95), and the intraclass correlation coefficient for repeated binary measures was 0.75 (95% CI 0.67–0.81). Conclusions There is a substantial agreement between IP-CUS and DUS for PLEDVT screening in trauma patients in ICU with high risk for DVT. Large multicentre studies are needed to confirm this finding.

Test-Retest-Reliability of Computer-Based Metamorphopsia Measurement in Macular Diseases

2020 ◽  
Author(s):  
Daniela Claessens ◽  
Alexander K. Schuster ◽  
Ronald V. Krüger ◽  
Marian Liegl ◽  
Laila Singh ◽  
...  
Keyword(s):  
Macular Edema ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Measuring Method ◽  
Repeated Measurements ◽  
Retest Reliability ◽  
Macular Diseases ◽  
Computer Based ◽  
Test Retest Reliability

AbstractIn this study, the test-retest-reliability as one aspect of reliability of metamorphopsia measurements using a computer-based measuring method was determined in patients with macular diseases. Metamorphopsia amplitude, position, and area were quantified using AMD – A Metamorphopsia Detector software (app4eyes GmbH & Co. KG, Germany) in patients with diabetic, myopic, or uveitic macular edema, intermediate or neovascular age-associated macular degeneration, epiretinal membrane, vitelliform maculopathy, Irvine-Gass syndrome, or macular edema due to venous retinal occlusion. The intraclass correlation coefficient (ICC) was calculated in order to determine the repeatability of two repeated measurements and was used as an indicator of the reliability of the measurements. In this study, metamorphopsia measurements were conducted on 36 eyes with macular diseases. Metamorphopsia measurements made using AMD – A Metamorphopsia Detector software were highly reliable and repeatable in patients with maculopathies. The intraclass correlation coefficient of all indices was excellent (0.95 – 0.97). For diseases of the vitreoretinal interface or macular diseases with intra- or subretinal edema, this metamorphopsia measurement represents a supplement for visual function testing in the clinic, as well as in clinical studies.

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