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Three Part Question

In [adult patients with a suspected scaphoid fracture], is [MRI is better than CT scan] in [diagnosing the fracture with an initially negative X-ray result]?

Clinical Scenario

A 25-year-old right-handed carpenter came to the Emergency Department (ED) with a recent history of a fall onto his outstretched hand. He complained of pain in the wrist and some tenderness was reported in the anatomical snuffbox. The subsequent X-ray showed no abnormality. Should the patient undergo another investigation, such as an MRI, there and then?

Search Strategy

Ovid MEDLINE(R) 1950 to June Week 4 2010
[exp Scaphoid Bone OR exp Carpal Bones OR scaphoid$.mp. OR exp Fractures, Bone OR fracture$.mp]
Limit to English language AND humans AND all adult (19 plus years).
AND
[exp Magnetic Resonance Imaging OR magnetic resonance imaging$.mp. OR MRI$.mp. OR MR scan$.mp.]
AND
[exp Tomography, X-Ray Computed OR computed tomography scan$.mp. OR CT scan$.mp]

Search Outcome

Twenty papers were identified in Medline, only one paper was relevant to the three-part question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Memarsadeghi M et al. 2006 Austria	29 patients (17 male, 12 female), mean age: 34 years old Presented with suspected scaphoid fracture but negative initial radiograph, underwent MR imaging and multidetector CT within 6 days after trauma.	Diagnostic cohort studies, Prospective	MRI Accuracy* of detecting All fractures vs cortical fractures (*Test confirmed by follow up radiograph at 6 weeks = 11 scaphoid fracture)	29/29 vs 6/11	Small sample size, Publication bias was not mentioned
			CT Accuracy of detecting All fractures vs cortical fractures	26/29 vs 11/11
			MRI vs MDCT Sensitivity	100% (CI:75%,100%) vs 73% (CI: 87%,100%)
			MRI vs MDCT Specificity	100% (CI: 52%,100%) vs 100% (CI: 48%, 89%)

Comment(s)

As this study compares multidetector CT to MRI, other types of CT scan, namely longitudinal or sagittal section, may show different results.

Clinical Bottom Line

MRI is superior to CT scan in detecting scaphoid fractures in patients who experience negative initial radiograph findings. However, more research needs to be done to compare these two diagnostic tools to answer the question.

References

1. Memarsadeghi M. Breitenseher MJ. Schaefer-Prokop C. Weber M. Aldrian S. Gabler C. Prokop M. Occult scaphoid fractures: comparison of multidetector CT and MR imaging--initial experience. Radiology 2006; 240(1):169-76.[Erratum appears in Radiology. 2007 Mar;242(3):950].