A diagnostic accuracy of 69% for abnormal focal echogenicity within the plantar fascia, 60% for edema around the plantar fascia, 78% for perifascial edema, 69% for rupture of the plantar fascia, and 56% for an associated calcaneal spur have been found for US, using MRI as the reference standard [55]. Kapoor et al [56] showed higher sensitivity and specificity of US elastography when compared to US in the detection of plantar fasciitis (95% and 100% versus 66% and 75%, respectively), using MRI as the reference standard. US has been shown to be useful in the diagnosis of complete and partial tears of the plantar fascia [57]. Some authors regard US to be superior to MRI in differentiating true fiber interruption and tearing of the plantar fascia from edema [58]. Variant 5: Nonradiating chronic midfoot pain of suspected osseous origin. Radiographs negative or equivocal. Clinical concern includes occult fracture, or painful accessory ossicles. Next imaging study. Bone Scan Foot Bone scintigraphy is a sensitive but not specific technique to detect occult fractures because of its capability to detect increased osteoblastic activity. Although bone scans may reveal focal uptake at the site of a radiographically occult fracture, given the anatomical complexity of the foot particularly the midfoot, precise localization may be limited [59]. SPECT/CT may improve the diagnosis of patients with suspected fractures because of the more precise anatomical localization [60]. Symptomatic accessory navicular bones were initially studied with Tc-99m-MDP bone scans and were reported to show increased radiotracer uptake at the synchondrosis, apparently due to the chronic stress reaction [61]. A negative bone scan can exclude the presence of a symptomatic accessory ossicle, but positive findings lack specificity [62]. Isotope bone scans, when combined with CT, may be positive in cases of painful accessory ossicles but remain relatively insensitive for some soft-tissue pathology [63].
Chronic Foot Pain. A diagnostic accuracy of 69% for abnormal focal echogenicity within the plantar fascia, 60% for edema around the plantar fascia, 78% for perifascial edema, 69% for rupture of the plantar fascia, and 56% for an associated calcaneal spur have been found for US, using MRI as the reference standard [55]. Kapoor et al [56] showed higher sensitivity and specificity of US elastography when compared to US in the detection of plantar fasciitis (95% and 100% versus 66% and 75%, respectively), using MRI as the reference standard. US has been shown to be useful in the diagnosis of complete and partial tears of the plantar fascia [57]. Some authors regard US to be superior to MRI in differentiating true fiber interruption and tearing of the plantar fascia from edema [58]. Variant 5: Nonradiating chronic midfoot pain of suspected osseous origin. Radiographs negative or equivocal. Clinical concern includes occult fracture, or painful accessory ossicles. Next imaging study. Bone Scan Foot Bone scintigraphy is a sensitive but not specific technique to detect occult fractures because of its capability to detect increased osteoblastic activity. Although bone scans may reveal focal uptake at the site of a radiographically occult fracture, given the anatomical complexity of the foot particularly the midfoot, precise localization may be limited [59]. SPECT/CT may improve the diagnosis of patients with suspected fractures because of the more precise anatomical localization [60]. Symptomatic accessory navicular bones were initially studied with Tc-99m-MDP bone scans and were reported to show increased radiotracer uptake at the synchondrosis, apparently due to the chronic stress reaction [61]. A negative bone scan can exclude the presence of a symptomatic accessory ossicle, but positive findings lack specificity [62]. Isotope bone scans, when combined with CT, may be positive in cases of painful accessory ossicles but remain relatively insensitive for some soft-tissue pathology [63].