An 'eye of a needle' technique was used during this procedure. This involves inserting the needle in line with the x-ray beam and it will often appear as a dot if perfectly aligned or as it's shown in this case, the hub is slightly off-center from the tip.  Due to the projection, the needle appears short, despite being 90mm long.  

Different volumes of arthrogram injectate should be used in different joints, a total volume of 10mL was used for this MRI hip arthrogram injection.  

Further reading available in Arthrogram (MRI).