Intra- and inter-rater reproducibility of ultrasound imaging of patellar and quadriceps tendons in critically ill patients

Abstract

Since the outset of body image reconstruction for diagnosis purposes, ultrasound has been used to investigate structural changes located in tendons. Ultrasound has clinical applications in the intensive care unit, but its utility for tendon imaging remains unknown. Thus, we aimed to determine intra- and inter-rater reproducibility of measures obtained by images generated through morphological tendon sonographic analysis recorded from critically ill patients. We designed a cross-sectional study to assess thickness, cross-sectional area, and echogenicity of patellar and quadriceps tendons in a convenience sample formed with 20 critically ill patients. Two independent raters (experienced and novice) recorded repeated measures, checking for agreement (Kappa statistics) and reliability (Intraclass coefficient Correlation-ICC and Bland-Altman). The quality of images acquired by the two independent raters substantially agreed (k = 0.571–1.000), regardless of the region on the patellar tendon or the studied tendon (patellar or quadriceps). Regardless of how much experience the rater had, their repeated records (intra-rater reliability) always demonstrated almost complete correlation, ICC ranging from 0.89 to 0.98 for both tendons in all outcomes. At the same way, the statistically significant inter-rater ICC ranging from 0.87 to 0.97. Both repeated measures by the raters (intra-rater) and the repeated single and double measures between the raters (inter-rater) presented a minimum measurement error constituting a predominant pattern of random variability. We conclude that ultrasound imaging acquisition performed by independent raters for tendon thickness, CSA, and echogenicity monitoring of critically ill patients are acceptable and are not influenced by rater experience.

Reliability of ultrasound in evaluating the plantar skin and fat pad of the foot in the setting of diabetes

“…Intra-observer agreement was demonstrated for all tissue characterisation assessments, which included echogenicity and definition, excepting for the fat pad (layers 2–4) at the heel, and the skin (layer 1) at the lateral sesamoid foot region. We did not demonstrate inter-observer agreement for any tissue characterisation assessments, supporting the view that assessments of ultrasound tissue characteristics of musculoskeletal structures are highly subjective and variable [ 26 – 28 ], even when assessed by experienced sonographers using defined protocols. Therefore, these assessments have limited clinical applicability where multiple sonographers may be involved.…”

“…However, the reliability of ultrasound measurements of the plantar skin and fat pad thickness are not well documented [ 25 ]. Ultrasound can also be used to depict tissue characteristics other than thickness, but such assessments are often overlooked, including those of the plantar foot in diabetic people, due to their perceived subjectivity [ 26 – 28 ]. Consequently, the reliability of ultrasound for describing plantar tissue characteristics in the setting of diabetes remains unknown.…”

Quadriceps and Patellar Tendon Thickness and Stiffness in Elite Track Cyclists: An Ultrasonographic and Myotonometric Evaluation

“…The highest post-race increase in QT thick was found at location placed 15 mm (Δ post-pre: 0.23 mm in the sprint and 0.17 mm in endurance track cyclists), while PT thick at 15 mm (Δ post-pre: 0.36 mm) in sprinters and 20 mm (Δ post-pre: 0.29 mm) in endurance cyclists. Castro et al ( 2019 ) have reported that the middle region of PT Thick (~20 mm) was the easiest to define and had the highest intra-rater reliability. Such increases in the tendon thickness are most likely caused by including hypoechogenicity and vascularity (Visnes et al, 2015 ; Tsui et al, 2017 ).…”

Evaluating a Muscle Ultrasound Education Program: Theoretical Knowledge, Hands-on Skills, Reliability, and Satisfaction of Critical Care Physiotherapists

“…The qualitative interpretation of the ICC was classified as 0.00 (absent), 0.00-0.19 (poor), 0.20-0.39 (weak), 0.40-0.59 (moderate), 0.60-0.79 (good), and ≥0.80 (excellent). 35 The SEM was calculated for each ICC value as the product of SD and the square root (1−single measures ICC). The coefficient of variation (CV) was calculated by dividing the SD by the mean value of the repeated measures (CV=[SD/mean] × 100), interpreted as CV<10 (very good), 10-20 (good), 20-30 (acceptable), and CV>30 (not acceptable).…”