A directed approach to MRI of the athletic knee.

Surface coil MRI is now frequently utilized to assess acutely injured knees. In dedicated athletes, unique considerations exist which modify standard diagnosis and therapy. Concrete clinical findings must justify the potential loss of livelihood from even a "negative" arthroscopy. Seventeen injured athletes were evaluated by an orthopedic surgeon experienced in sports injuries and a preliminary localizing diagnosis was rendered, followed by knee MRI. Of 17 patients with significant injuries, MRI agreed with operative findings or clinical follow-up in 15 cases. Knee MRI prompted early intervention in those patients with conflicting subjective and/or objective findings. Furthermore, it helped direct the arthroscopist's surgical approach and encouraged close examination of areas less optimally visualized arthroscopically. MR and arthroscopy were complementary modalities in diagnosing certain ligamentous and cartilaginous lesions. MR effectively evaluated the cruciate ligaments often difficult to visualize by arthroscopy; arthroscopy better assessed articular surfaces. A cooperative effort existed between orthopedic surgeon and radiologist in directing both the MR study and arthroscopy. This was of particular benefit in maximizing scan efficiency in these large individuals who often filled the gantry. The team directed approach between orthopedic surgeon and radiologist affords deliberate and efficient diagnosis and therapy in this select population.

MRI of the athletic knee. Findings in asymptomatic professional basketball and collegiate football players.

For the dedicated athlete in whom minor injuries are frequent and major injuries relatively common, a noninvasive knee assessment could either obviate the need for arthroscopy or focus its direction. The opportunity to study asymptomatic athletes was not feasible before the advent of magnetic resonance imaging (MRI). In this preliminary work, we examined 40 knees in 20 asymptomatic volunteer athletes, including five professional basketball players and 15 collegiate football players. Images were obtained at 0.5 T or 1.5 T. Spin echo sequences were used to obtain 5.0 mm thick coronal and sagittal sections. Fifty percent of asymptomatic athletes (10/20) had significant baseline MRI abnormalities that could have adversely affected scan interpretation in the context of an acute injury. Half of these athletes with MRI abnormalities, or 25% of the total (5/20), had no previous surgery and were unaware of significant injury.

MR imaging diagnosis of rotator cuff tears.

Thirty-one symptomatic patients were studied with MR imaging to evaluate the sensitivity and specificity of shoulder MR in the diagnosis of rotator cuff tears. Correlative studies included arthroscopy in 19 patients and arthrography in 12 patients. Images were obtained on either a 0.5- or 1.5-T Philips superconducting magnet using spin-echo pulse sequences (650-850/30 [TR, TE], 2000/30, 100) with 5-mm slices oriented in an oblique coronal plane perpendicular to the glenohumeral joint. The MR studies were initially interpreted without knowledge of the results of other diagnostic procedures. The MR diagnosis of cuff tear was made when irregularity, discontinuity, and increased signal were identified in the rotator cuff. MR images showed tears in 10 patients (32%) and were negative for tear in 21 patients (68%). MR correlated with arthroscopy and arthrography in 17 of 18 normal patients, in eight of 10 patients with complete tears, and in one of three patients with partial tears. For complete rotator cuff tears, the sensitivity, specificity, and accuracy were 80%, 94%, and 89%, respectively. For all tears (partial and complete), the sensitivity, specificity, and accuracy were 69%, 94%, and 84%, respectively. These data suggest that MR imaging is an accurate procedure for the diagnosis of complete rotator cuff tears. The number of partial tears (three) in this series is too small to evaluate the value of MR imaging in the diagnosis of partial tears.