Lea H. Niemitukia MD, Presenter: Nothing to Disclose

Urho Väätäinen, Abstract Co-Author: Nothing to Disclose

Heikki Kröger, Abstract Co-Author: Nothing to Disclose

Imke Höfling, Abstract Co-Author: Nothing to Disclose

Petri Sipola MD, Abstract Co-Author: Nothing to Disclose

To compare the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) for the detection of rotator cuff tears and measurement of the size of tears, with arthroscopic or open surgery used as the standard of reference.

Seventy six consecutive patients (39M/37F; age range, 42-76 years) presenting to the experienced orthopedic surgeon with signs and symptoms sufficiently suspicious for a diagnosis of rotator cuff tear were recruited in a prospective study. All patients were studied with US and MRI with and without intra-articular contrast using 1.5T scanner. The presence or absence of a full or partial-thickness tear and the tear maximal size as demonstrated by each imaging test and at the time of surgery (2.4 ± 2.9 months after imaging) were recorded.

With data combined for complete and partial tears of the rotator cuff (n = 66), US had a sensitivity, specificity, positive and negative predictive value of 95%; 40%, 91% and 57%, respectively. Corresponding values in MRI were 97%, 80%, 97% and 80%. 15 patients need to be imaged with MRI to make one additional correct diagnosis when compared to US only. Both imaging methods underestimated actual tear maximal size. However, underestimation was smaller in MRI compared to US (4 ± 13 mm vs 15 ± 14 mm, P < .001).

Both US and MRI are accurate methods to diagnose rotator cuff rupture in a highly selected patient group, but US gives more false positive results. MRI is more accurate to quantitate cuff tear size.

Most patients with suspected rotator cuff tear can be diagnosed with US. However, the tear size can be markedly underestimated if diagnose is made by US only.

Niemitukia, L, Väätäinen, U, Kröger, H, Höfling, I, Sipola, P, Detection and Quantification of Rotator Cuff Tears by US and MRI: A Prospective Study with 76 Consecutive Patients.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5004148.html