Influence of MRI field strength on clinical decision making in knee cartilage injury - A case study

To increase clinicians' awareness of the differences in image resolution and potential diagnostic accuracy between small and large-field MR Scanners. To present an example of a clinical decision making challenge in how to proceed when knee MRI and clinical findings don't agree.

A 38 year old female mountain biker presented with knee pain and clinical features strongly suggestive of a torn meniscus or loose bodies. An initial MRI using a small field strength (0.18T) scanner was reported as normal. Her clinical presentation was suspicious enough that a repeat MRI on a high-field (1.5T) scanner was ordered. The second MRI included high resolution 3D volumetric imaging which revealed cartilage damage and loose bodies.

The patient was treated with arthroscopic surgery which confirmed the presence of meniscal and chondral injury and resulted in notable improvement in the patient's symptoms.

Clinicians should consider scanner quality and diagnostic accuracy before discounting strongly suggestive clinical history and examination findings when MRIs are reported as normal.