Ultrasound Assessment of Medial Meniscal Extrusion: A Validation Study Using MRI as Reference Standard

Abstract

OBJECTIVE. The purpose of this article is to validate both semiquantitative and quantitative ultrasound assessment of medial meniscal extrusion using MRI assessment as the reference standard. SUBJECTS AND METHODS. Ninety-three consecutive patients with chronic knee pain referred for knee MRI were evaluated by ultrasound and MRI on the same day. Two musculoskeletal radiologists assessed meniscal extrusion on ultrasound and MRI separately and independently and graded it semiquantitatively as follows: 0 (< 2 mm), 1 (≥ 2 mm and < 4 mm), and 2 (≥ 4 mm). Agreement between the ultrasound and MRI evaluations was determined using weighted kappa statistics. Intraclass correlation coefficients were used to evaluate agreement using the absolute values of extrusion (quantitative assessment). We further evaluated the diagnostic performance of ultrasound for the detection of medial meniscal extrusion using MRI as the reference standard. RESULTS. For semiquantitative grading, agreement between ultrasound and MRI was moderate for reader 1 (κ = 0.57) and substantial for reader 2 (κ = 0.64). Substantial agreement was found for both readers (intraclass correlation coefficients, 0.73 and 0.70) when comparing quantitative assessment of meniscal extrusion between ultrasound and MRI. Ultrasound showed excellent sensitivity (95% and 96% for each reader) and good specificity (82% and 70% for each reader) in the detection of meniscal extrusion. CONCLUSION. Ultrasound assessment of meniscal extrusion is reliable and can be used for both quantitative and semiquantitative assessment, exhibiting excellent diagnostic performance for the detection of meniscal extrusion compared with MRI.

Useful ultrasonographic evaluation of the medial meniscus as a feature predicting the onset of radiographic knee osteoarthritis

“…US requires no special facility, and is a very useful imaging diagnostic tool for simple and non-invasive imaging examinations of the joints of the four limbs (extremity) [8]. In the knee joint, US is capable of visualizing not only ligament and cartilage injuries, but also meniscal damage, and the joint may be evaluated in real time with and without weight bearing, which makes it the most appropriate imaging diagnostic device for the screening of knee OA [11]. MRD presented in this study is an abnormality of the meniscus detectable by US, and has recently been attracting attention for its involvement in the onset and progression of knee OA [5,12,18].…”

“…Based on the above findings, US appears to be very useful in imaging examinations for the screening of knee OA including pre-OA and early-OA because it is capable of simply and noninvasively evaluating meniscal function, [10,11]. However, previous studies were cross-sectional or short-term studies, and changes with time from pre-OA to early-OA, i.e., the process or characteristics of changes from a functional to dysfunctional meniscus, were not clarified, and, thus, were insufficient to clarify the usefulness of the evaluation of MRD as an index to identify those at risk of developing knee OA.…”

Ultrasound of knee osteoarthritis: interobserver agreement and correlation with Western Ontario and McMaster Universities Osteoarthritis

“…Popliteal cyst is often simple and may be containing linear bands or debris [34]. Ultrasound is sensitive method for detection of meniscal extrusion in knee osteoarthritis [35].…”

Contrast-enhanced CT imaging as a non-destructive tool for ex vivo examination of the biochemical content and structure of the human meniscus

“…Due to the limitations of histology and conventional biochemical assays, there is a significant interest in the development of alternative (and nondestructive) imaging methods for assessing meniscus biochemical content. Clinically, the meniscus is most frequently imaged using native and contrast‐enhanced MRI . With the development of delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC), in vivo dGEMRIC studies have reported differences in the red (vascularized) and white (non‐vascularized) zones of the meniscus, differences in meniscal T1 relaxation times between osteoarthritic and healthy subjects, and relationships between T1 relaxation times of the meniscus and articular cartilage within the same subjects .…”

“…Clinically, the meniscus is most frequently imaged using native and contrast-enhanced MRI. [15][16][17][18][19] With the development of delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC), in vivo dGEMRIC studies have reported differences in the red (vascularized) and white (non-vascularized) zones of the meniscus, 18,20 differences in meniscal T1 relaxation times between osteoarthritic and healthy subjects, 21 and relationships between T1 relaxation times of the meniscus and articular cartilage within the same subjects. 19 However, dGEMRIC has yet to demonstrate associations with the biochemical content of the meniscus, either ex vivo or in vivo, which is critical for quantitative studies of OA pathogenesis.…”