MRI grows as go-to modality after equivocal ultrasound

If an abdominal ultrasound is equivocal, which imaging modality are radiologists turning to? Increasingly, the answer to that question is MRI, according to this Tuesday morning presentation by researchers from Massachusetts General Hospital (MGH) in Boston.

Supriya Gupta, MD, will discuss how MGH researchers wanted to look at which modality got the nod after equivocal ultrasound. They classified 1 million ultrasound exams acquired between 1993 and 2010, with recommendations for follow-up imaging in 203,000 cases.

Of those recommendations, ultrasound was recommended in 14% of cases, followed by biopsy in 11.1%, MRI in 7.9%, and CT in 5.8%. The rate of recommendations for MRI went from 4.6% in 1993 to 10.1% in 2009. Meanwhile, the rate of recommendations for CT fell from 16.4% in 1993 to 3.8% in 2009, while biopsy recommendations fell from 11.1% in 1993 to 5.8% in 2009.

However, the rate of recommendations for ultrasound remained about the same, from 14.2% in 1993 to 12.6% in 2009.

The authors concluded that the rate of growth for MRI may be due to the modality's higher test specificity compared to CT.