Diagnostic Ultrasound or MRI for Injuries?
Above: Imaging of the Shoulder with Diagnostic Ultrasound. A normal shoulder in a 30 year old woman. F- Fat. H- Humerus. D- Deltoid Muscle. Arrowhead- sub-deltoid sub-acromial bursa (normal=3mm). (Image courtesy of AJROnline.com)
Diagnosis changes everything.
If we can correctly and accurately find what is ailing you, we can better solve your injury as well as create your treatment plan.
In a new injury that is severe or a long term injury that refuses to heal (especially in the finger or shoulder), your physician will refer you out for advanced imaging. Usually beginning with the X-Ray as a basic snapshot, we gather injury information about bone alignment, joint health, and any swelling or foreign bodies (such as nails, staples, etc).
If we don't see anything on the X-Ray or if we have reason to believe that there is sufficient evidence to show joint damage or ligamentous or muscular damage that might change our treatment plan (or need surgery) we then refer out for a MRI or Diagnostic Ultrasound (mSK US).
Some studies have shown that Diagnostic Ultrasound is within 1% accuracy of modern MRI (Magnetic Resonance Imaging). Others state that the results are completely dependent on the education and training of your technician. This is true. Overall, diagnostic ultrasound is a great tool. In a paper written by John A Jacobson, the use of both modalities was compared.
"Teefey et al. showed in 100 consecutive shoulders with arthroscopic surgery confirmation that ultrasound was able to diagnose full-thickness rotator cuff tears with an accuracy of 96%. With regard to the detection of partial-thickness tears, an accuracy of 94% has been reported using ultrasound. MRI has similar accuracies of 92–97% for full-thickness rotator cuff tears and an accuracy of 92% for partial-thickness tears. Both ultrasound and MRI have also been shown to be of comparable accuracy for the identification and measurement of the size of rotator cuff tears."
(More of his above article can be read at this LINK.)
If you have a really good technician, they can see your pulley tendons, any tears in your rotator cuff, and any fractures in your finger or shoulder. A great modern method that compliments the MRI, it is non-toxic, doesn't expose you to radiation, and is much more affordable for cash patients.
In my office, I view with the Diagnostic Ultrasound to view if anything is abnormal and if I find something, I send it off for an MRI. We can clearly visualize if there is excessive motion of the flexor tendons due to a pulley rupture with dynamic testing which cannot be done on MRI. Additional benefits that make Diagnostic Ultrasound better than MRI are in the evaluation of soft tissue foreign bodies (such as nails or rocks), imaging small nerves in the skin and muscles, and any illnesses or injuries that require motion while imaging for proper diagnosis.
There is a downside to Diagnostic Ultrasound, each patient has different tissue materials in their tendon and muscle (such as levels of collagen), it is not always clear as an MRI might be. Also, the research is behind and its use (and results) completely depend on the technician and their skill level. One that is not trained to look at fingers as much as major arteries might not have the feedback that a climber wishes to know. Your doctor will best direct you to a clinician who is sports medicine in focus and/or training. This with the use of MRI will allow us to custom tailor your care, and your time off, to fit your injury.
Fun new improvements in sports medicine!
Jacobson, JA. Musculoskeletal ultrasound and MRI: which do I choose? Semin Musculoskelet Radiol. 2005 Jun;9(2):135-49.
Shah, Nilesh MD. Musculoskeletal Ultrasound: Imaging Modality of the Future. MDNews.com. Friday, May 27, 2011.
Wong-On M1, Til-Pérez L, Balius R. Evaluation of MRI-US Fusion Technology in Sports-Related Musculoskeletal Injuries.Adv Ther. 2015 Jun;32(6):580-94. doi: 10.1007/s12325-015-0217-1. Epub 2015 Jun 21.
van Holsbeeck MT, Kolowich PA, Eyler WR, et al. US depiction of partial-thickness tear of the rotator cuff. Radiology 1995; 197:443 –446 [CrossRef] [Medline]
Balich SM, Sheley RC, Brown TR, Sauser DD, Quinn SF. MR imaging of the rotator cuff tendon: interobserver agreement and analysis of interpretive errors. Radiology 1997; 204:191–194 [CrossRef] [Medline]
Vlychou M, Dailiana Z, Fotiadou A, Papanagiotou M, Fezoulidis IV, Malizos K. Symptomatic partial rotator cuff tears: diagnostic performance of ultrasound and magnetic resonance imaging with surgical correlation. Acta Radiol 2009; 50:101–105 [CrossRef] [Medline]
Teefey SA, Rubin DA, Middleton WD, Hildebolt CF, Leibold RA, Yamaguchi K. Detection and quantification of rotator cuff tears: comparison of ultrasonographic, magnetic resonance imaging, and arthroscopic findings in seventy-one consecutive cases. J Bone Joint Surg Am 2004; 86:708 –716 [Medline]
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