Original ArticleUltrasound elastography in the early diagnosis of plantar fasciitis
Introduction
Plantar fasciitis is a frequent cause of nontraumatic heel pain, which can be reduced by treatments such as steroid injections [1], [2]. The diagnostic criteria for plantar fasciitis include heel pain worsening at awakening in the morning or after a period of rest and tenderness at a medial tubercle of the calcaneus [3], [4]. Although ultrasound (US) is not necessary for the diagnosis of plantar fasciitis, it may confirm a diagnosis or be utilized as imaging guidance for injection procedures. Typical US findings of plantar fasciitis include thickening of the plantar fascia, loss of normal striation, a hypoechoic area within the fascia, and perifascial fluid [4]. These morphologic changes, however, are not always observed on US in patients with plantar fasciitis [4], [5]. US elastography was recently shown to be feasible in evaluating plantar fasciitis, showing softening of the plantar fascia in these patients [3]. In the cited study, most of patients showed abnormal findings consistent with plantar fasciitis on both B-mode imaging and elastography. To our knowledge, elastography has not been evaluated in patients with symptoms highly suggestive of plantar fasciitis but with normal findings on B-mode imaging. We therefore investigated whether US elastography can detect plantar fasciitis earlier than B-mode imaging.
Section snippets
Study population
The study was approved by our institutional review board and complied with Health Insurance Portability and Accountability Act guidelines. The board waived the requirement for informed consent for this retrospective study. Between May and December 2011, US examinations were performed on 64 symptomatic or asymptomatic feet. Longitudinal and short-axis B-mode imaging and longitudinal elastography imaging of both feet are included in the routine US protocol of our institute for patients with
Results
There were 7 right and 11 left feet in the patient group and 9 right and 9 left feet in the control group. The mean age of patients (45±11 years) and controls (46±14 years) did not differ significantly. Mean duration of pain in the patient group was 3.9±2.1 months. On B-mode US examination, the thickness of the plantar fascia did not differ significantly in patient (Reviewers 1 and 2, 2.9±0.7 mm each) and control (Reviewer 1, 2.6±0.6 mm; Reviewer 2, 2.5±0.6 mm) feet (Table 1). However, on US
Discussion
Plantar heel pain is a symptom commonly encountered by clinicians and may be due to conditions such as plantar fasciitis, calcaneal fracture, atrophy of heel fat pad, and nerve entrapment. US can help differentiate among the causes of heel pain, for example, by detecting extrinsic compression of the nerve tarsal tunnel by a ganglion cyst or neurogenic tumor. In patients with plantar fasciitis, US can show thickening of the plantar fascia and perifascial fluid collection [4]. If US findings are
Conclusion
In conclusion, US elastography may provide valuable information about the mechanical properties of the plantar fascia before morphologic changes during the early stages of plantar fasciitis. US elastography may improve diagnostic confidence during the early stages of plantar fasciitis.
References (18)
- et al.
Evaluation of human muscle hardness after dynamic exercise with ultrasound real-time tissue elastography: a feasibility study
Clin Radiol
(2011) Plantar fasciopathy
Sports Med Arthrosc
(2009)- et al.
High frequency ultrasonographic findings in plantar fasciitis and assessment of local steroid injection
J Rheumatol
(2000) - et al.
Sonoelastography of the plantar fascia
Radiology
(2011) - et al.
Plantar fasciitis: sonographic evaluation
Radiology
(1996) - et al.
Can sonoelastography detect plantar fasciitis earlier than traditional B-mode ultrasonography?
Am J Phys Med Rehabil
(2012) - et al.
Intraclass correlations: uses in assessing rater reliability
Psychol Bull
(1979) - et al.
The measurement of observer agreement for categorical data
Biometrics
(1977) - et al.
Predictive value for malignancy of suspicious breast masses of BI-RADS categories 4 and 5 using ultrasound elastography and MR diffusion-weighted imaging
AJR Am J Roentgenol
(2011)