Realtime elastography in plantar fasciitis: comparison with ultrasonography and MRI

Role of shear wave elastography in the diagnostic evaluation of plantar fasciitis: a prospective case-control study

OBJECTIVES

To assess the advantage of the addition of shear wave elastography (SWE) to gray-scale sonography in the diagnosis of plantar fasciitis.

METHODS

30 subjects between 18-60 years of age with unilateral heel pain who were clinically suspected of having plantar fasciitis were included in this study. Their affected feet were taken as cases; while their contralateral feet served as controls. On gray-scale ultrasound, the thickness of plantar fascia, its echopattern, presence of hypoechoic areas, and perifasicular collections were recorded. SWE was done by placing seven ROIs within the plantar fascia; and the mean of their Young's modulus was taken in kPa.

RESULTS

Plantar fascial thickening more than 4 mm had 70% sensitivity and 66.7% specificity, echopattern had 90% sensitivity and 96.7% specificity, hypoechoic areas had 80% sensitivity and 96.7% specificity, and perifascial edema had 26.7% sensitivity and 100% specificity for diagnosing plantar fasciitis. Using the ROC curve, the cut-off value of Young's modulus for the diagnosis of plantar fasciitis was found to be ≤ 99.286 kPa. This predicted plantar fasciitis with 97% sensitivity and 100% specificity. The primary diagnostic feature of ultrasound of plantar fascia thickness more than 4 mm detected 21 out of 30 cases of plantar fasciitis; whereas elastography detected an additional 8 cases which would have been missed on B-mode ultrasound alone.

CONCLUSIONS

SWE is a useful supplement and improves the diagnostic accuracy of gray-scale ultrasound in plantar fasciitis.

ACR Appropriateness Criteria® Chronic Foot Pain

Chronic foot pain is a frequent clinical complaint, which can significantly impact the quality of live in some individuals. These guidelines define best practices with regards to requisition of imaging studies based on specific clinical scenarios, which have been grouped into different variants. Each variant is accompanied by a brief description of the usefulness, advantages, and limitations of different imaging modalities. The present narrative is the result of an exhaustive assessment of the available literature and a thorough review process by a panel of experts on Musculoskeletal Imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Application of ultrasound in the assessment of plantar fascia in patients with plantar fasciitis: a systematic review

Plantar fasciitis (PFS) is one of the most common causes of heel pain, estimated to affect 10% of the general population during their lifetime. Ultrasound (US) imaging technique is increasingly being used to assess plantar fascia (PF) thickness, monitor the effect of different interventions and guide therapeutic interventions in patients with PFS. The purpose of the present study was to systematically review previously published studies concerning the application of US in the assessment of PF in patients with PFS. A literature search was performed for the period 2000-2012 using the Science Direct, Scopus, PubMed, CINAHL, Medline, Embase and Springer databases. The key words used were: ultrasound, sonography, imaging techniques, ultrasonography, interventional ultrasonography, plantar fascia and plantar fasciitis. The literature search yielded 34 relevant studies. Sixteen studies evaluated the effect of different interventions on PF thickness in patients with PFS using US; 12 studies compared PF thickness between patients with and without PFS using US; 6 studies investigated the application of US as a guide for therapeutic intervention in patients with PFS. There were variations among studies in terms of methodology used. The results indicated that US can be considered a reliable imaging technique for assessing PF thickness, monitoring the effect of different interventions and guiding therapeutic interventions in patients with PFS.

Integrating active shape models into ultrasound elastography to diagnose musculoskeletal injuries: a 2D simulation study

We build on ultrasound elastography (UE) by offering a new method for diagnosing musculoskeletal injuries from estimated tissue displacements. Our strategy is to isolate the portion of tissue displacements that arise due to injury. Active shape models are constructed capturing displacement variation among normal tissue. New tissue is then evaluated by estimating displacements with (1) the active shape models and (2) a traditional UE tracking algorithm. The difference between the two estimates defined virtual axial displacement and used to identify injured tissue. Our method was tested by simulating planar tissue examined with ultrasound elastography. Images are presented of axial displacement and virtual axial displacement as well as axial strain and virtual axial strain, i.e. partial derivative of the respective displacements with respect to the axial coordinate. Injured tissue and uninjured tissue were not statistically different when comparing mean absolute value of axial strain covarying with the loading conditions. In contrast, uninjured tissue and injured tissue were statistically different when comparing absolute value of virtual axial strain covarying with loading conditions (p < 0.0001). Statistical significance was considered p < 0.05.