[Update: clinical imaging of cartilage-part 1 : Technical aspects].

backgroundIn order to answer clinical therapy-oriented questions, reliable and consistent depiction of articular cartilage across technical platforms is necessary. MATERIALS AND

methodsTechnical standards and developments in cartilage imaging are summarized based on current literature and experience from clinical daily routine.

resultsClinical questions that need to be answered relate to cross-sectional extent, depth, differentiating cartilaginous from bony components of a lesion and to the lesion's location within the compartment. If present, displaced fragments, concomitant meniscal, ligamentous and/or degenerative lesions should be identified. To date, magnetic resonance imaging (MRI) is the workhorse of cartilage imaging and is largely based on moderately T2-weighted and also proton-density (PD)-weighted fat-suppressed turbo-spin-echo sequences. Direct MR- and CT-arthrography are the gold standard to evaluate thin cartilage layers. Recent advances in coil and MR sequence design, increased availability of 3T-MR scanners and more and more sophisticated acceleration techniques allow for better spatial resolution and more robust image contrast at acceptable scan times. DISCUSSION: As abundant as current developments in clinical routine cartilage imaging may be, the radiologist must carefully select the approach best suited to answering the clinical questions.