Educational benefits of fusing magnetic resonance imaging with sonograms.

PURPOSE: To investigate whether providing sonographic (US)/MRI fusion images will enhance the ability of medical students and radiology residents to identify MSK anatomy on sonograms alone. METHODS: Medical students (n = 31) and radiology residents (n = 23) were each randomly divided into two groups: Group A and Group B. Subjects in Group A were shown 10 MSK sonograms with arrows pointing to a specific anatomic structure or anatomic region. Subjects in Group B were shown the exact same 10 annotated sonograms as Group A as well as an additional fusion image consisting of an MRI of the same anatomy in the same plane fused with the sonogram without arrows. Sonograms and MRI were obtained from adult patients who consented to have their images used. The anatomic regions included the shoulder, hip, and pelvis. Both groups were given the same 10-question multiple choice examination to identify the anatomic structure that the arrow was marking on the sonogram. The transducer's location was given for every question. One minute was allowed to answer each question. The Wilcoxon rank sum test was used to assess if there was a difference between Group A and Group B in both the medical student and the radiology resident cohorts. RESULTS: Medical students: subjects in Group A (n = 16) gave the correct answers in 33.8% of the cases (54/160). Subjects in Group B (n = 15) gave correct answers in 26.0% of the cases (39/150) (p value <0.110). Radiology residents: subjects in Group A (n = 11) gave correct answers in 40.9% of the cases (45/110). Subjects in Group B (n = 12) gave correct answers in 72.5% of the cases (87/120) (p value <0.001). CONCLUSION: The addition of a fusion MRI/US image enhances radiology residents' ability to identify MSK US anatomy accurately compared with the sonogram alone. The medical students, however, did not show improvement with the addition of the fusion MRI/sonogram. 2014.

Review of three magnetic resonance arthrography related infections.

We report three cases of intra-articular infection which followed injection for magnetic resonance arthrography. In an effort to reduce the risk of arthrogram related infection, representatives from radiology, infectious disease medicine, and microbiology departments convened to analyze the contributing factors. The proposed source was oral contamination from barium swallow studies which preceded the arthrogram injections in the same room. We propose safety measures to reduce incidence of arthrogram related infections.

Evaluation of magnetic resonance imaging following neuraxial steroid administration: does epidural injection produce pathologic findings?

BACKGROUND AND OBJECTIVES: Infection or hematoma following epidural anesthesia is a rare but potentially devastating complication unless diagnosed early. In order to diagnose spinal cord involvement, the currently recommended imaging test is magnetic resonance imaging (MRI). Despite this, no previous studies have been performed to define typical MRI findings following uneventful epidural injection. The purpose of this pilot study was to compare magnetic resonance images before and after epidural injection to define the characteristic appearance of MRI following an uneventful epidural steroid injection. METHODS: Ten patients were prospectively enrolled and received an MRI study before and after an epidural injection of steroids plus local anesthetic for chronic low back pain using a loss of resistance to air technique. The magnetic resonance images were reviewed by 2 neuroradiologists who were blinded as to whether the scan was performed before or after the epidural injection. RESULTS: Review of 20 MRI studies revealed no fluid collections, hematomas, or mass effect on the thecal sac. A needle track and a small amount of epidural air was seen in the majority of post-epidural scans, but did not cause indentation of the thecal sac in any patient. None of the findings observed by the radiologists in the post-epidural scans were considered clinically significant. CONCLUSIONS: The results of this pilot study demonstrated that after uneventful epidural injection in otherwise healthy patients, there were no new pathologic findings on MRI scans. Further MRI studies in large populations and in different clinical situations should be performed to confirm these preliminary findings.