A normal plain radiograph does not always exclude osteomyelitis as a diagnosis.
Date First Published:
June 28, 2007
Last Updated:
July 9, 2007
Report by:
Charlotte Houltram, medical student (Manchester Royal Infirmary)
Search checked by:
Charlotte Houltram, Manchester Royal Infirmary
Three-Part Question:
In a [diabetic patient] with a [deep infected foot wound] does [MRI or plain radiography have a better clinical utility for diagnosig osteomyelitis?]
Clinical Scenario:
A 58 year old male patient with long standing diabetes mellitus and peripheral neuropathy presented to the emergency department after having noticed a deep wound to the plantar aspect of his left foot. You suspect osteomyelitis and wonder what would be the most appropriate imaging modality- plain radiograph or MRI.
Search Strategy:
Medline from 1950 to June 2007 through the ovid interface and Embase from 1996 to week 25 2007
Search Details:
(exp diabetes mellitus OR exp diabetic neuropathies OR exp diabetic foot) AND (exp osteomyelitis) AND (exp magnetic resonance imaging OR MRI.mp. OR exp x-ray OR plain radiograph.mp.) LIMIT to humans AND English language
Outcome:
The search located 69 papers, 2 of which were relevant
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Nuclear medicine imaging of diabetic foot infection: results of meta-analysis Capriotti G, Chianelli M, Signore A. 2006 Italy | 57 papers (50 original research articles and 7 reviews) that described the imaging of the diabetic foot and examined a total of 2889 lesions. | meta-analysis | MRI and x-rays efficacy in the diagnosis of osteomyelitis | In the diagnosis of osteomyelitis MRI has a sensitivity of 90.1% (x-ray 61.9.5) a specificity of 73.9% (x-ray 67.5%) an accuracy of 80.5% (x-ray 65.6) a positive predictive value of 87.3% (x-ray 71.3%) and a negative predictive value of 85.7% (x-ray58.5%) | |
| Magnetic Resonance Imaging for Diagnosing Foot osteomyelitis. Kapoor A, Page S, LaValley M, Gale DR, Felson DT. 2007 USA | 496 patients from 16 studies into the diagnostic performance of different imaging techniques in osteomyelitis. At least one site with the disease and one without were identified by the gold reference standard (e.g. bone biopsy) | meta-analysis | DOR and specificity of MRI and x-ray for the detection of osteomyelitis | The diagnostic odds ratio for MRI was 42.1% and the specificity (at a 90% cut point) was 82.5%. This is consistently better than for plain radiography (81.5 vs 3.3) | Although the authors mention that the studies were evaluated for inclusion (and the inclusion criteria) the paper does not mention what sort of studies were included or their validity. |
Author Commentary:
Both papers found were large, well conducted meta-analysis of the data and agree that MRI has a markedly better diagnostic performance than x-ray at detecting osteomyelitis.
Bottom Line:
In patients with suspected osteomyelitis MR Imaging is a better tool for diagnosis than x-ray.
References:
- Capriotti G, Chianelli M, Signore A.. Nuclear medicine imaging of diabetic foot infection: results of meta-analysis
- Kapoor A, Page S, LaValley M, Gale DR, Felson DT.. Magnetic Resonance Imaging for Diagnosing Foot osteomyelitis.