Magnetic resonance imaging of the knee

Abstract

Magnetic resonance imaging (MRI) is an accepted non-invasive modality for evaluation of soft tissue pathology without exposure to ionizing radiation. Current applications demonstrate excellent visualization of the anatomy and pathology of various organs. Preliminary studies in the knee reveal fine resolution of anatomy and pathology involving the meniscus. The purpose of this study is to determine a prospective correlation between MRI scans and actual meniscal pathology as documented at the time of arthroscopy. MRI scans were obtained in 155 patients, on 156 knees (one patient with bilateral scans), with 86 patients (87 knees) eventually undergoing diagnostic and operative videoarthroscopy performed by the same surgeon (DWJ). All images were obtained on the same high-resolution 1.5 Tesla GE Signa Magnetic Resonance Scanner with the same radiologist performing all readings (PEB). The knees were studied in the coronal and sagittal plane using a spin echo sequence and 5 mm slice thicknesses. The menisci were described as having Grade 1, 2, or 3 changes, with Grade 3 reserved for complete tears. Using arthroscopy as the diagnostic standard, the accuracy of MRI in diagnosing medial and lateral meniscal tears was 93.1% and 96.6%, respectively with a Grade 3 MRI reading. For tears of the ACL, the accuracy was 96.6% as confirmed at arthroscopy. Five tears of the PCL were also documented by MRI and correlated with clinical evaluation. Other abnormalities seen were articular cartilage and osteochondral defects, bone tumors, tibial plateau fractures, Baker's cysts, and meniscal cysts. The MRI scan is a highly accurate, noninvasive modality for documentation of meniscal pathology as well as cruciate ligament tears in the knee.

Meniscal bucket handle tears: a retrospective study of arthroscopy and the relation to MRI

“…The frequency of this sign was given as 97% [6,5]. In our series the frequency of this sign was 88.8%.…”

“…The presence of double PCL sign, double anterior horn sign, flipped meniscus sign, disproportional posterior horn sign were less common (41.66, 33, 25, and 27.7%, respectively) (Figs. 4,5,6,7,8). As it appears in Table 2, a few combinations of the above signs have been found in significant frequency.…”

Osteochondral lesions and cruciate ligament injuries: MRI in 18 knees

“…The accuracy of diagnosis by MRI of the knee compared to arthroscopy has been reported to range from 64 to 95 percent for the medial meniscus, from 83 to 94 percent for the lateral meniscus, and from 78 to 97 percent for the anterior cruciate ligament (Jackson et al 1988, Lee et al 1988, Fischer et al 1991. The study by Rosen et al (1991) implies that when the anterior ligament is tom, there is an 85 percent chance that the patient also has sustained an osseous lesion seen on the MRI.…”

Mri Assessment of Clinically Suspected Meniscal Tears

“…8 Currently, MRI of the knee for detecting internal derangement has an accuracy rate of more than 90% by most studies. 9 This study has been designed to assess MRI yield in a sample of patients with knee injuries.…”