 Introduction/Background Ankle pain is considered chronic when symptoms persist >6 weeks. Chronic ankle pain can be caused by a variety of osseous or soft-tissue abnormalities, either alone or in combination. For assessing chronic ankle pain, there are multiple imaging options, including radiography, stress radiography, computed tomography (CT) radionuclide bone scanning, ultrasound (US), magnetic resonance imaging (MRI), and various injection procedures. Injection procedures include arthrography, CT arthrography, MR arthrography, and diagnostic injection with anesthetic agents. Although there are numerous causes for chronic ankle pain, common etiologies include osteoarthritis, osteochondral injury, tendon abnormalities, ligament abnormalities and instability, and impingement. Overview of Imaging Modalities Radiography Radiographs can provide information about the osseous and soft-tissue structures about the ankle. Routine radiographs of the ankle typically include anteroposterior, lateral, and mortise views, the latter obtained by internally rotating the foot 15 to 20 degrees. Stress radiographs can be used to assess ankle instability [1,2]; however, some have questioned their accuracy [3,4]. CT CT CT is not routinely used as a first-line imaging tool in chronic ankle pain, but it is more sensitive than radiographs, particularly for osseous abnormalities [5]. CT arthrography may be more accurate than MR arthrography for the identification of osteochondral abnormalities [6]. Bone Scan Conventional planar bone scintigraphy can assess osseous pathology. More recently, single-photon emission computed tomography (SPECT) combined with CT has been shown to provide additional information compared with clinical diagnosis and conventional bone scintigraphy for the evaluation of impingement syndromes and soft- tissue pathology [7]. In addition, SPECT/CT abnormalities have been shown to significantly correlate with pain in osteochondral lesions [8].
Chronic Ankle Pain.  Introduction/Background Ankle pain is considered chronic when symptoms persist >6 weeks. Chronic ankle pain can be caused by a variety of osseous or soft-tissue abnormalities, either alone or in combination. For assessing chronic ankle pain, there are multiple imaging options, including radiography, stress radiography, computed tomography (CT) radionuclide bone scanning, ultrasound (US), magnetic resonance imaging (MRI), and various injection procedures. Injection procedures include arthrography, CT arthrography, MR arthrography, and diagnostic injection with anesthetic agents. Although there are numerous causes for chronic ankle pain, common etiologies include osteoarthritis, osteochondral injury, tendon abnormalities, ligament abnormalities and instability, and impingement. Overview of Imaging Modalities Radiography Radiographs can provide information about the osseous and soft-tissue structures about the ankle. Routine radiographs of the ankle typically include anteroposterior, lateral, and mortise views, the latter obtained by internally rotating the foot 15 to 20 degrees. Stress radiographs can be used to assess ankle instability [1,2]; however, some have questioned their accuracy [3,4]. CT CT CT is not routinely used as a first-line imaging tool in chronic ankle pain, but it is more sensitive than radiographs, particularly for osseous abnormalities [5]. CT arthrography may be more accurate than MR arthrography for the identification of osteochondral abnormalities [6]. Bone Scan Conventional planar bone scintigraphy can assess osseous pathology. More recently, single-photon emission computed tomography (SPECT) combined with CT has been shown to provide additional information compared with clinical diagnosis and conventional bone scintigraphy for the evaluation of impingement syndromes and soft- tissue pathology [7]. In addition, SPECT/CT abnormalities have been shown to significantly correlate with pain in osteochondral lesions [8].