Early magnetic resonance imaging compared with bone scintigraphy in suspected scaphoid fractures

Abstract

We evaluated 100 consecutive patients with a suspected scaphoid fracture but without evidence of a fracture on plain radiographs using MRI within 24 hours of injury, and bone scintigraphy three to five days after injury. The reference standard for a true radiologically-occult scaphoid fracture was either a diagnosis of fracture on both MRI and bone scintigraphy, or, in the case of discrepancy, clinical and/or radiological evidence of a fracture. MRI revealed 16 scaphoid and 24 other fractures. Bone scintigraphy showed 28 scaphoid and 40 other fractures. According to the reference standard there were 20 scaphoid fractures. MRI was falsely negative for scaphoid fracture in four patients and bone scintigraphy falsely positive in eight. MRI had a sensitivity of 80% and a specificity of 100%. Bone scintigraphy had a sensitivity of 100% and a specificity of 90%. This study did not confirm that early, short-sequence MRI was superior to bone scintigraphy for the diagnosis of a suspected scaphoid fracture. Bone scintigraphy remains a highly sensitive and reasonably specific investigation for the diagnosis of an occult scaphoid fracture.

Adult Scaphoid Fracture

“…[36][37][38][39][40] Among more recent, prospective ED-based studies that used MRI or bone scan as criterion standards, the prevalence of scaphoid fractures in patients with appropriate clinical suspicion and nondiagnostic initial x-rays ranges from 17% to 38%. [37][38][39][40] Therefore, based on these four prospective, ED-based diagnostic studies including a total of 274 patients, we think a reasonable pretest probability for adult ED patients with persistent wrist pain suspicious for a scaphoid fracture while still in the ED and normal ED x-rays is 25%. In other words, one in four of these patients will have a scaphoid fracture diagnosed on subsequent imaging.…”

“…38,40,56,[65][66][67][68][69][70][71][72][73][74][75][76][77][78][79] All of the pre-1995 studies used an x-ray/clinical examination composite as the criterion standard, although the timing of this follow-up evaluation ranged from 14 days to 1 year. After 1995, several studies also included MRI as an acceptable criterion standard.…”

“…38,64,72,74,75,88,91,[95][96][97][98][99][100] Investigators reported a variety of criterion standards, including clinical evalua- Figure 12. Ultrasound forest plots.…”

“…CT forest plots. tion at 14 days, 100 x-ray alone at 6 or 11 weeks, 88,98 x-ray plus clinical evaluation at 6 weeks, 95,96 MRI alone, 91,99 MRI plus x-ray, 38 or MRI plus x-ray and bone scan. 74 In most studies, MRI imaging used a 0.1-to 1.5-Tesla unit with two sequences: a coronal T1-weighted spin-echo and a coronal and transverse short-tau inversion recovery (STIR) sequence.…”

Imaging of Scaphoid Fractures According to the New S3 Guidelines

“…The utilization of three-phase scintigraphy is supported by the high negative predictive value after the third day post-injury, the high positive predictive value in the case of patients with an initial negative X-ray finding and simultaneous evidence of injury to the remaining bones of the hand [13,17,22]. Due to its poor spatial resolution and low specificity, positive findings in scintigraphy must always be supplemented by a subsequent CT and/or MRI diagnosis.…”