Wooden splinter-induced extremity injuries: Accuracy of MRI evaluation

ObjectiveTo detect the accuracy of MR imaging in detection and localization of wooden splinters invading the extremities using surgical data as a reference standard.MethodsA retrospective review on a series of eighteen patients with: history of wooden foreign body penetration and/or localized swellings to their extremities, surgically confirmed final diagnosis of wooden foreign body penetration and having both screening X-ray and MR imaging of their concerned extremities.MR imaging included variable combination of fast-spin echo imaging in T1W and T2W without fat-suppression as well as fat-suppressed proton density and/or STIR sequences. Gadolinium-enhanced imaging was available in 10 of the MR studies of our patients only.ResultsSuccessful localization using MR was achieved in sixteen patients only, in the current study with sensitivity and specificity of 88.8%. Wooden splinters were recognized as linear signal void on T1, T2 and PD weighted images surrounded by reactive inflammatory changes. In the remaining two cases, wooden splinters were missed on MRI due to their tiny size.ConclusionsCharacteristic target appearance of signal void wooden splinter and surrounding inflammatory changes on MR imaging of unusual soft-tissue masses of the extremities should alert radiologist to the possibility of wooden-splinter induced granuloma.