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Objective: Extremity cone-beam CT (CBCT) scanners have become available for clinical use in the United States. The purpose of this study was to review an initial clinical experience with CBCT of the foot and ankle in pediatric patients., Materials and Methods: A retrospective review was conducted of all foot or ankle CBCT examinations performed on patients 18 years old and younger at one institution from August 1, 2013, through February 28, 2015. A t test was used to compare mean effective dose for CBCT with that for MDCT foot or ankle examinations of age-matched control subjects. To assess changes in utilization, a t test also was used to compare the mean numbers of foot or ankle CT examinations per month before and after installation of the CBCT scanner at the institution., Results: Thirty-four CBCT examinations were performed. The mean effective dose was 0.013 ± 0.003 mSv compared with 0.023 ± 0.020 mSv for MDCT of age-matched control subjects (p < 0.005). The mean numbers of foot or ankle CT examinations per month were 3.4 in the 18 months before and 3.8 in the 18 months after installation of the CBCT scanner (p = 0.28). The mean number of foot or ankle MDCT examinations per month decreased significantly (3.4 vs 1.9, p = 0.03) over the same period. In 56% of patients, CBCT revealed important findings that were not visible on contemporaneous radiographs. In 68% of patients, the CBCT findings affected clinical management., Conclusion: CBCT of the foot or ankle of pediatric patients is a viable lower-dose alternative to MDCT that provides important information that may affect clinical management.

Objective: The purpose of this study was to assess changes in accuracy, degree of confidence, and evaluation time in radiography of subtle foot fractures when the text history is supplemented by a graphic indicating the site of pain., Materials and Methods: Radiographs from 226 foot examinations (three views), including 126 examinations showing one subtle fracture (< 1-mm displacement) and 100 examinations with normal findings were selected. In the first interpretation session, only a text history was given for 112 examinations, and both text and a graphic indicating the site of pain for 114 examinations. Six months later, a graphic and text history were provided for the 112 cases interpreted without a graphic in the first session, and only text was provided for the other 114 cases. Seven radiologists evaluated the study sets. Sensitivity, specificity, degree of confidence (1-10 scale), and mean interpretation time in seconds were calculated., Results: Use of a graphic increased overall sensitivity for any subtle fracture from 67% to 73% (p < 0.001), increased degree of confidence from 8.1 without a graphic to 8.4 with a graphic (p < 0.0001), and decreased the time for interpretation by 6%, from 53 seconds without a graphic to 50 seconds with a graphic (p = 0.006). Specificity changed from 93% without a graphic to 94% with a graphic (p = 0.33). Fractures of the third metatarsal were missed most frequently (74%); this percentage improved to 61% with use of a graphic., Conclusion: A graphic complements the text history by improving sensitivity, degree of confidence, and time for interpretation.

Objective: Previous studies have found that fractures involving the spine, hands, and feet are rare on skeletal surveys in cases of suspected child abuse, leading some authors to suggest eliminating these regions from the initial skeletal survey protocol. We assessed this recommendation by performing a historical review of these injuries in a pediatric population undergoing film screen-based radiographic skeletal surveys for suspected child abuse., Materials and Methods: This cross-sectional retrospective study reviewed reports of initial skeletal surveys of all children younger than 2 years with suspected abuse imaged between April 1988 and December 2001. Radiographic skeletal survey imaging was performed according to American College of Radiology standards. Sixty-two percent (225/365) of all skeletal surveys had positive findings, and 44% (98/225) showed more than one fracture. Surveys with fractures involving the spine, hands, or feet were identified, and the data were tabulated and analyzed., Results: Twenty of 365 studies (5.5%) yielded fractures involving the spine, hands, or feet. Of all positive skeletal surveys, 8.9% (20/225) had fractures involving the spine, hands, or feet. Of all patients with more than one fracture on skeletal survey, 20.4% (20/98) had fractures involving these regions., Conclusion: These data, acquired during the film-screen era, suggest that fractures of the spine, hands, and feet may not be rare in infants and toddlers in cases of suspected child abuse. The benefits of eliminating views of these regions from the initial skeletal survey should be carefully weighed against the cost of missing these potentially important injuries in at-risk pediatric populations.

Objective: This article selectively reviews several areas in which imaging can play a major role in the diagnosis and treatment of sports injuries of the foot., Conclusion: Diagnostic imaging provides useful evaluation of capsuloligamentous sports injuries and Morton neuroma in the foot and facilitates appropriate treatment. An understanding of the relevant anatomy, normal imaging appearance, and the spectrum of imaging findings in the setting of injury is important for the practicing radiologist.

Objective: The purpose of this study is to determine the diagnostic accuracy of radiographs in the diagnosis of Lisfranc injury. In addition, a foot phantom was investigated to determine the optimum degree of craniocaudal angulation on the anteroposterior radiograph to best show the joint. The angle of the joint in patients with midfoot injury was investigated to determine the optimum degree of craniocaudal angulation., Materials and Methods: Sixty patients examined by CT had their radiographs evaluated independently and by consensus opinion by two observers, and the diagnostic performance was calculated using CT as the reference standard. A foot phantom was radiographed with varying degrees of craniocaudal angulation, and the radiograph that best revealed the joint was determined. This was compared with the angle of the joint as measured on CT. The angle of the joint in all 60 patients was measured on CT., Results: The radiographs correctly identified 31 of the 45 cases (68.9%) of Lisfranc injury, with a positive predictive value of 84.4%, a negative predictive value of 53.3%, a sensitivity of 84.4%, and a specificity of 53.3%. Twenty degrees of craniocaudal angulation best showed the second tarsal-metatarsal joint of the phantom, and this correlated with a 20° angle measured by CT. The mean (± SD) angle of the joint in the patients was 28.9° ± 5.7°., Conclusion: Conventional radiographs miss a significant number of cases of Lisfranc injury. Craniocaudal angulation can better show the joint, and an angle of 28.9° is likely to optimally visualize the joint in the majority of patients.

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging spectrum of pediatric foot alignment issues.

Objective: The purpose of our study was to assess MDCT findings and the advantages of MDCT compared with radiography in patients referred to a level 1 trauma center for diagnostic evaluation of acute ankle and foot trauma., Materials and Methods: During a period of 37 months, 388 patients underwent MDCT of the ankle and foot due to an acute trauma. Imaging studies (MDCT and radiography) were retrospectively reevaluated with respect to fracture location, fracture type, and mechanism of injury, and findings from the primary radiographs of the ankle and foot were compared with MDCT findings., Results: Of the 388 patients, 344 (89%) had one or more fractures in the ankle or foot. A total of 517 fractures were found in all anatomic regions: ankle, calcaneus, talus, midfoot, and forefoot. The three most common occult fractures in the ankle not detected on primary radiography were isolated fractures of the posterior and medial malleolus and Tillaux fractures. The calcaneus was the most commonly fractured bone, and the sensitivity of radiography in the detection of calcaneal fractures was 87%. The sensitivity of radiography in the detection of talar fractures was 78%, whereas it was only 25-33% in the detection of midfoot fractures. A Lisfranc fracture-dislocation was not detected on primary radiography in five (24%) of 21 cases. The three main injury mechanisms were falling from a height (164 patients [48%]), a simple fall (68 patients [20%]), and a traffic accident (47 patients [14%])., Conclusion: In patients with injuries from high-energy polytrauma and in those with complex ankle and foot fractures, the sensitivity of radiography is only moderate to poor; in these cases, MDCT is recommended as the primary imaging technique.

Objective: The purpose of this study was to evaluate the utility of selective injection of local anesthetic into hindfoot articulations for localizing the source of posttraumatic pain and to compare clinical response with the severity of degenerative change in the various articulations evident on plain radiographs or CT scans., Subjects and Methods: Anesthetic arthrography was performed in 18 patients with posttraumatic hindfoot pain. In all, 32 joints were assessed: 15 talocalcaneonavicular, 11 subtalar, five ankle, and one calcaneocuboid. Following intraarticular injection of a mixture of equal amounts of meglumine diatrizoate 60%, lidocaine 1%, and bupivacaine 0.25%, patients were asked to grade the degree of pain relief they experienced on a scale from 0% to 100%. The degree of degenerative changes seen on preliminary radiographs and CT scans was graded blindly and retrospectively by an experienced musculoskeletal radiologist using a 3-point scale (grade 0 indicated a normal joint, grade 1 indicated mild to moderate degenerative change, and grade 2 indicated severe degenerative change). The value of findings on both routine radiographs and CT scans as predictors of the degree of symptomatic relief obtained from specific joint injections was determined. Arthrodesis was performed in nine patients on the basis of the results of anesthetic injections., Results: The degree of pain relief experienced after intraarticular injection of anesthetic correlated with the severity of degenerative change as assessed by routine radiography in 15 of 32 joints and as assessed by CT in eight of 18 joints. In 14 of 32 joints assessed by routine radiography and in seven of 18 joints assessed by CT, the amount of pain relief achieved by anesthetic arthrography was less than that predicted by imaging evidence of degenerative disease. In five of 32 joints judged normal on plain film radiographs, significant pain relief was experienced following anesthetic injection, resulting in a change in the proposed surgical procedure. Long-term follow-up indicated satisfactory results in eight of the nine patients in whom arthrodesis was performed., Conclusion: Selective intraarticular anesthetic injections afford a direct method of confirming the site of hindfoot pain and may aid in surgical planning, because plain film radiography or CT may underestimate or poorly indicate the most symptomatic articulations.