PurposeTo examine the precision of cine‐phase contrast (PC) magnetic resonance imaging (MRI) techniques as applied to the quantification of three‐dimensional knee joint kinematics.Materials and MethodsThe knee joints of eight healthy volunteers were studied using three different dynamic, PC MRI protocols: cine‐PC (one average), cine‐PC (two averages), and cine‐PC with segmented phase encoding (fast‐PC).ResultsFast‐PC has comparable precision, shorter scan times, and improved subject interexam variability (SIEV) compared to cine‐PC (two averages). Further, cine‐PC (one average) has low precision and high SIEV, making fast‐PC the preferred method of data acquisition. Specifically, the precision of fast‐PC MRI in measuring knee joint kinematics ranged from 0.22°–1.16°.ConclusionA cine‐PC MRI technique utilizing segmented phase encoding (fast‐PC MRI) acquires dynamic data at a faster rate than other PC imaging protocols, without compromising data precision. Being able to acquire precise 3D kinematics with shorter imaging times is critical if we are to use this technique to advance ongoing research in musculoskeletal kinematics. J. Magn. Reson. Imaging 2003;17:206–213. © 2003 Wiley‐Liss, Inc.

In order to correctly diagnose and treat pathological knee joint mechanics we must be able to non-invasively quantify the 3D in vivo kinematics of this joint. Unfortunately, the majority of clinical diagnoses, for this joint, are based upon static 2D imaging. This is due to the fact that currently there is a scarcity of noninvasive measurement techniques that acquire 3D in vivo data dynamically. Thus, in vivo patellofemoral (PF) kinematic measurements typically compress a 3D time-dependent joint attitude to a static 2D representation. The purpose of this study was to investigate if patellar maltracking is limited to two dimensions, as assumed clinically, or if it is a complete six-degree of freedom problem. To do this, we quantified the 3D patellofemoral and tibiofemoral (TF) kinematics in both healthy individuals and those with suspected patellofemoral maltracking using fast-phase contrast magnetic resonance imaging, a technique developed in our previous work. Our data suggest that variations in kinematics were not confined to the standard axial plane measures (e.g. patellar tilt, patellar subluxation), but variations are exhibited in all six degrees of freedom. Therefore, future clinical diagnoses and interventions along with future research will be most effective if the measures used are broadened to include all six-degrees of freedom.