General practitioner-referred magnetic resonance imaging for musculoskeletal conditions: not a substitute for plain x-ray
To the Editor: In November 2012, the Australian Government extended requesting rights for Medicare-eligible magnetic resonance imaging (MRI) scans to general practitioners for “a small set of clinically appropriate indications”1 in patients under the age of 16 years. The purpose was
avoiding exposure of children to unnecessary radiation associated with other types of diagnostic imaging like computed tomography (CT) scans.1
With musculoskeletal MRI, a Medicare-eligible scan is performed “following radiographic examination”.1
Plain x-ray, rather than MRI, remains the gold standard for diagnosing most musculoskeletal conditions in children, and we report two cases where the initial use of MRI rather than x-ray led to a delay in diagnosis.
First, an 11-year-old girl was investigated for a 3-month history of left knee pain and locking. An ultrasound and MRI scan (Box 1, A) were performed, although an x-ray was not done. As no cause for the symptoms was identified on the ultrasound or MRI, the patient was referred to an orthopaedic surgeon, who requested an x-ray (Box 1, B). This showed a large proximal tibial spur tethering the semitendinosis tendon. This…