High‐resolution ultrasonographic diagnosis of plantar fasciitis: a correlation of ultrasound and magnetic resonance imaging

Aim and Method: In a prospective study of nine men and eight women with suspected unilateral or bilateral plantar fasciitis, 23 symptomatic heels were examined by both high‐resolution ultrasound and a preplanned limited sagittal magnetic resonance imaging (MRI) protocol to assess the different signs. Eleven healthy volunteers (22 heels) acted as controls. Results: The plantar fascia was thickened in symptomatic feet. The thickness of the plantar fascia in symptomatic feet was (3.0–7.0 mm; 4.9 ± 1.3) measured by ultrasound which was significantly thicker than in the control group (1.1–2.4 mm; 1.7 ± 0.06); P < 0.05. Other sonographic signs used for the diagnosis of plantar fasciitis in the study were compared to MRI findings. The diagnostic accuracy was 69.5% for abnormal focal echogenicity within the plantar fascia, 60.8% for edema around the plantar fascia, 78.2% for perifascial edema, 69.5% for rupture of the plantar fascia and the lowest diagnostic accuracy of ultrasound was in detection of associated calcaneal spur (56.5%). The findings were tabulated and discussed in relation to other literature. Conclusion: It was concluded that the diagnostic accuracy of ultrasound is comparable to that of MRI in the diagnosis of plantar fasciitis and it could be the straightforward initial imaging modality to confirm clinically suspected plantar fasciitis. MRI may be reserved for cases where a diagnosis of plantar fasciitis does not satisfactorily explain the clinical presentation and when complex pathology is suspected.