T2 black lesions on routine knee MRI: differential considerations

Abstract

The majority of abnormal findings or lesions on T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) are hyperintense due to increased perfusion or fluid content, such as infections, tumours or synovitis. Hypointense lesions on T2-weighted images (both fat-suppressed and non-fat-suppressed) are less common and can sometimes be overlooked. Such lesions have limited differential diagnostic possibilities, and include vacuum phenomenon, loose body, tenosynovial giant cell tumour, rheumatoid arthritis, haemochromatosis, gout, amyloid, chondrocalcinosis, hydroxyapetite deposition disease, lipoma arborescens, arthrofibrosis and iatrogenic lesions. These lesions often show characteristic appearances and predilections in the knee. In this article, the authors describe the MRI features of hypointense T2 lesions on routine knee MRI and outline a systematic diagnostic approach towards their evaluation. Key Points • Hypointense lesions on T2 images (T2 Dark Lesions) encompass limited diagnostic possibilities. • T2 Dark lesions often show characteristic appearances and predilections in the knee. • A systematic diagnostic approach will help radiologists make the correct diagnosis.

Evaluation of Chondrocalcinosis and Associated Knee Joint Degeneration Using MR Imaging: Data from the Osteoarthritis Initiative

“…Additionally, we randomly selected controls (group B) from the subjects in whom we confirmed the absence of radiographic evidence for chondrocalcinosis in either knee and absence of punctate foci of hypointensity on the gradient echo sequences and/or punctuate foci of hyperintensity on the FSE sequences, studded along the hyaline cartilage and menisci, as previously described [16], in order to confirm that group B did not include subjects with CaCs that were not detected with plain radiographs.…”

T2-weighted Hypointense Tumors and Tumor-like Lesions

“…8f) that gradually becomes more fibrotic and hypointense over time. 37 Focal rice bodies are also a characteristic of RA (described later).…”

“…It should be differentiated from a hematoma secondary to trauma. 37 In GCTTS, cellular elements are embedded in a dense fibrous capsule, 36 differentiating it from diffuse PVNS. LowT2wSI and the blooming artifacts on T2GRE images are less frequently encountered in nodular synovitis when compared with diffuse PVNS.…”

“…Diffuse arthrofibrosis is infrequent but may be encountered. 37 T2 hypointense intra-articular bodies derive from denuded cartilage, broken osteophytes, osteochondral lesions, or meniscal fragments, usually on the grounds of degenerative arthritis. They are conspicuously seen as hypointense filling defects on T2WI 34 against the high signal of the joint fluid/ effusion, rarely free in the joint, and more commonly attached to the joint synovium.…”

Magnetic resonance imaging of the knee: An overview and update of conventional and state of the art imaging

“…However, the differential diagnosis of T 2 hypointensity in the joint still remains broad, including other entities such as gout and amyloid. The presence of gradient susceptibility blooming on a gradient echo image is compatible with hemosiderin from either PVNS or prior hemarthrosis, thus adding a gradient echo image (Fig. ) can limit the differential diagnosis.…”