Objective. To systematically evaluate the MR findings in patients with
epicondylitis compared with asymptomatic volunteers. Design and patie
nts. We imaged 43 elbows: 24 with epicondylitis (22 lateral, 2 medial)
diagnosed by clinical examination, and 19 in 16 normal volunteers. MR
I was performed at 1.5 T using axial T1-weighted, axial fat-saturated
FSE, and coronal or sagittal Fast STIR sequences. Two independent obse
rvers evaluated the images for intratendon signal, tendon thickening,
periosteal reaction, fluid in the radial head bursa, and anconeus edem
a. Results. All 24 patients with epicondylitis had increased signal on
fat-saturated FSE and Fast STIR images. Twenty-two of these patients
had increased intratendon T1 signal, and 19 had tendon thickening. No
patient demonstrated fluid in the radial head bursa or periosteal reac
tion. Only two patients had subtle anconeus edema, while three patient
s unexpectedly had increased T2 signal within the involved epicondyle.
One asymptomatic volunteer (high-performance athlete) had increased T
1 and T2 signal with tendon thickening. An additional two asymptomatic
volunteers had increased T1 signal only. Conclusion. MRI of epicondyl
itis demonstrates tendon thickening with increased T1 and T2 signal, b
ut these findings may be seen in a small minority of asymptomatic indi
viduals. Anconeus edema, previously demonstrated on MRT in epicondylit
is, was only rarely found, and distension of the radial head bursa, su
rgically described, was not seen. Increased marrow T2 signal within th
e involved epicondyle is occasionally seen.