The comparison of measurement accuracy among three different imaging modalities in evaluating elastofibroma dorsi. An analysis of 52 cases.

PURPOSE: Elastofibroma dorsi (ED) is a rare soft-tissue tumour. Diagnosis is made using imaging, mainly magnetic resonance due to its higher sensitivity and specificity in soft tissues. No agreement exists when deciding which imaging test must be used. Often multiple tests are made in the same patient, increasing time and costs. The aim of this paper is to compare the usual imaging exams and evaluate which one is the most accurate when diagnosing and measuring ED.

METHODS: A retrospective review was made of those patients who were diagnosed and operated for ED since January 2006 to December 2013. Fifty-two ED were included (19 men, 25 women), and eight of them were bilaterally affected. They were divided into three different groups according to the imaging test used: ultrasound (US) computed tomography (CT) and magnetic resonance (MR). After surgery the pieces were sized and compared with the measurements made by imaging exams.

RESULTS: Two hundred fourteen measures were analysed (40 US, 33 CT and 34 MR with their pathological equivalent). When CT group and its corresponding AP were analysed, no significant differences between them were founded (p > 0.05). Moreover, we analysed absolute differences between measures. In the US group a mean difference of 2.23 ± 1.87 cm was obtained. In the CT group, the mean difference was 1.22 ± 0.97 cm. Likewise, the difference of the MR group was 1.62 ± 1.15 cm.

CONCLUSIONS: This study demonstrates that the CT obtains a higher correlation than MR when determining the size of ED.