Overcoming Human Barriers to Safety Event Reporting in Radiology.

In high-reliability industries that are dedicated to ensuring safety, safety event reporting is the cornerstone of improvement. However, human factors can interfere with consistent reporting. Common human factors that are barriers to safety event reporting include liability concerns; time constraints; physician autonomy; self-regulation; collegiality; the lack of listening, language training, and/or feedback regarding reported events; unclear responsibilities within safety teams; and a high reporting threshold. Other barriers include fears of challenging authority, being disrespected, retribution, and the creation of a difficult work environment. These factors are reviewed in the health care setting, and the countermeasures that need to be introduced at the frontline employee, leadership employee (physicians and managers), and departmental and organizational levels to create a culture of safety in which all employees feel comfortable raising safety concerns are discussed. ©RSNA, 2019.

Barriers to Safety Event Reporting in an Academic Radiology Department: Authority Gradients and Other Human Factors.

Purpose To investigate barriers to reporting safety concerns in an academic radiology department and to evaluate the role of human factors, including authority gradients, as potential barriers to safety concern reporting. Materials and Methods In this institutional review board-approved, HIPAA-compliant retrospective study, an online questionnaire link was emailed four times to all radiology department staff members (n = 648) at a tertiary care institution. Survey questions included frequency of speaking up about safety concerns, perceived barriers to speaking up, and the annual number of safety concerns that respondents were unsuccessful in reporting. Respondents' sex, role in the department, and length of employment were recorded. Statistical analysis was performed with the Fisher exact test. Results The survey was completed by 363 of the 648 employees (56%). Of those 363 employees, 182 (50%) reported always speaking up about safety concerns, 134 (37%) reported speaking up most of the time, 36 (10%) reported speaking up sometimes, seven (2%) reported rarely speaking up, and four (1%) reported never speaking up. Thus, 50% of employees spoke up about safety concerns less than 100% of the time. The most frequently reported barriers to speaking up included high reporting threshold (69%), reluctance to challenge someone in authority (67%), fear of disrespect (53%), and lack of listening (52%). Conclusion Of employees in a large academic radiology department, 50% do not attain 100% reporting of safety events. The most common human barriers to speaking up are high reporting threshold, reluctance to challenge authority, fear of disrespect, and lack of listening, which suggests that existing authority gradients interfere with full reporting of safety concerns.

Acing the Joint Commission Regulatory Visit: Running an Effective and Compliant Safety Program.

Ensuring the safety of patients and staff is a core effort of all health care organizations. Many regulatory agencies, from The Joint Commission to the Occupational Safety and Health Administration, provide policies and guidelines, with relevant metrics to be achieved. Data on safety can be obtained through a variety of mechanisms, including gemba walks, team discussion during safety huddles, audits, and individual employee entries in safety reporting systems. Data can be organized on a scorecard that provides an at-a-glance view of progress and early warning signs of practice drift. In this article, relevant policies are outlined, and instruction on how to achieve compliance with national patient safety goals and regulations that ensure staff safety and Joint Commission ever-readiness are described. Additional critical components of a safety program, such as department commitment, a just culture, and human factors engineering, are discussed. ©RSNA, 2018.

Impact of Communication Errors in Radiology on Patient Care, Customer Satisfaction, and Work-Flow Efficiency.

OBJECTIVE: The purpose of this study is to analyze the impact of communication errors on patient care, customer satisfaction, and work-flow efficiency and to identify opportunities for quality improvement. MATERIALS AND METHODS: We performed a search of our quality assurance database for communication errors submitted from August 1, 2004, through December 31, 2014. Cases were analyzed regarding the step in the imaging process at which the error occurred (i.e., ordering, scheduling, performance of examination, study interpretation, or result communication). The impact on patient care was graded on a 5-point scale from none (0) to catastrophic (4). The severity of impact between errors in result communication and those that occurred at all other steps was compared. Error evaluation was performed independently by two board-certified radiologists. Statistical analysis was performed using the chi-square test and kappa statistics. RESULTS: Three hundred eighty of 422 cases were included in the study. One hundred ninety-nine of the 380 communication errors (52.4%) occurred at steps other than result communication, including ordering (13.9%; n = 53), scheduling (4.7%; n = 18), performance of examination (30.0%; n = 114), and study interpretation (3.7%; n = 14). Result communication was the single most common step, accounting for 47.6% (181/380) of errors. There was no statistically significant difference in impact severity between errors that occurred during result communication and those that occurred at other times (p = 0.29). In 37.9% of cases (144/380), there was an impact on patient care, including 21 minor impacts (5.5%; result communication, n = 13; all other steps, n = 8), 34 moderate impacts (8.9%; result communication, n = 12; all other steps, n = 22), and 89 major impacts (23.4%; result communication, n = 45; all other steps, n = 44). In 62.1% (236/380) of cases, no impact was noted, but 52.6% (200/380) of cases had the potential for an impact. CONCLUSION: Among 380 communication errors in a radiology department, 37.9% had a direct impact on patient care, with an additional 52.6% having a potential impact. Most communication errors (52.4%) occurred at steps other than result communication, with similar severity of impact.

Does CT-based Rigidity Analysis Influence Clinical Decision-making in Simulations of Metastatic Bone Disease?

BACKGROUND: There is a need to improve the prediction of fracture risk for patients with metastatic bone disease. CT-based rigidity analysis (CTRA) is a sensitive and specific method, yet its influence on clinical decision-making has never been quantified. QUESTIONS/PURPOSES: What is the influence of CTRA on providers' perceived risk of fracture? (2) What is the influence of CTRA on providers' treatment recommendations in simulated clinical scenarios of metastatic bone disease of the femur? (3) Does CTRA improve interobserver agreement regarding treatment recommendations? METHODS: We conducted a survey among 80 academic physicians (orthopaedic oncologists, musculoskeletal radiologists, and radiation oncologists) using simulated vignettes of femoral lesions presented as three separate scenarios: (1) no CTRA input (baseline); (2) CTRA input suggesting increased risk of fracture (CTRA+); and (3) CTRA input suggesting decreased risk of fracture (CTRA-). Participants were asked to rate the patient's risk of fracture on a scale of 0% to 100% and to provide a treatment recommendation. Overall response rate was 62.5% (50 of 80). RESULTS: When CTRA suggested an increased risk of fracture, physicians perceived the fracture risk to be slightly greater (37% ± 3% versus 42% ± 3%, p < 0.001; mean difference [95% confidence interval {CI}] = 5% [4.7%-5.2%]) and were more prone to recommend surgical stabilization (46% ± 9% versus 54% ± 9%, p < 0.001; mean difference [95% CI] = 9% [7.9-10.1]). When CTRA suggested a decreased risk of fracture, physicians perceived the risk to be slightly decreased (37% ± 25% versus 35% ± 25%, p = 0.04; mean difference [95% CI] = 2% [2.74%-2.26%]) and were less prone to recommend surgical stabilization (46% ± 9% versus 42% ± 9%, p < 0.03; mean difference [95% CI] = 4% [3.9-5.1]). The effect size of the influence of CTRA on physicians' perception of fracture risk and treatment planning varied with lesion severity and specialty of the responders. CTRA did not increase interobserver agreement regarding treatment recommendations when compared with the baseline scenario (κ = 0.41 versus κ = 0.43, respectively). CONCLUSIONS: Based on this survey study, CTRA had a small influence on perceived fracture risk and treatment recommendations and did not increase interobserver agreement. Further work is required to properly introduce this technique to physicians involved in the care of patients with metastatic lesions. Given the number of preclinical and clinical studies outlining the efficacy of this technique, better education through presentations at seminars/webinars and symposia will be the first step. This should be followed by clinical trials to establish CTRA-based clinical guidelines based on evidence-based medicine. Increased exposure of clinicians to CTRA, including its underlying methodology to study bone structural characteristics, may establish CTRA as a uniform guideline to assess fracture risk. LEVEL OF EVIDENCE: Level III, economic and decision analyses.

Improving Safety through Human Factors Engineering.

Human factors engineering (HFE) focuses on the design and analysis of interactive systems that involve people, technical equipment, and work environment. HFE is informed by knowledge of human characteristics. It complements existing patient safety efforts by specifically taking into consideration that, as humans, frontline staff will inevitably make mistakes. Therefore, the systems with which they interact should be designed for the anticipation and mitigation of human errors. The goal of HFE is to optimize the interaction of humans with their work environment and technical equipment to maximize safety and efficiency. Special safeguards include usability testing, standardization of processes, and use of checklists and forcing functions. However, the effectiveness of the safety program and resiliency of the organization depend on timely reporting of all safety events independent of patient harm, including perceived potential risks, bad outcomes that occur even when proper protocols have been followed, and episodes of "improvisation" when formal guidelines are found not to exist. Therefore, an institution must adopt a robust culture of safety, where the focus is shifted from blaming individuals for errors to preventing future errors, and where barriers to speaking up-including barriers introduced by steep authority gradients-are minimized. This requires creation of formal guidelines to address safety concerns, establishment of unified teams with open communication and shared responsibility for patient safety, and education of managers and senior physicians to perceive the reporting of safety concerns as a benefit rather than a threat.

Spectrum and detection of musculoskeletal findings on trauma-related CT torso examinations.

This study aims (1) to evaluate the spectrum of musculoskeletal (MSK) findings detected on trauma-related torso CT exams performed in the emergency department and (2) to identify the findings of high clinical importance that are underreported. Following IRB approval, two fellowship-trained MSK radiologists independently reviewed 200 consecutive trauma CT torso examinations performed at a level 1 trauma center, focusing on MSK findings. Discrepancies were resolved by consensus. Findings were categorized as of high, moderate, or low clinical importance based on criteria established with an orthopedic trauma surgeon. Findings evident on only one series (scout, axial, or sagittal/coronal reformations) were documented. The consensus reading was compared to the final report. Unreported findings of high clinical importance were entered into our departmental QA system. Eighty-two percent (164/200) of the studies had at least one MSK finding. There were 433 total findings of varying importance and the overall detection rate was 61 % (266/433). The detection rate for high importance findings was 80 % (177/221) with the majority representing acute fractures (99 %). For findings of high clinical importance, the lowest detection rates were for fractures of the sternum, proximal humerus, and forearm. Of the high severity findings, 6.3 % (14/221) were detected only on sagittal or coronal reformatted or scout images. Twenty percent of musculoskeletal findings of high clinical importance on trauma-related CT torso exams were not reported. Fractures of the sternum, proximal humerus, and forearm were the most commonly missed fractures and review of scout and multiplanar reformations can increase detection.

A needs assessment of musculoskeletal fellowship training: a survey of practicing musculoskeletal radiologists.

OBJECTIVE: The purpose of this study was to conduct a needs assessment of musculo-skeletal radiologists regarding their musculoskeletal training experience and attitude toward a standardized musculoskeletal fellowship curriculum. MATERIALS AND METHODS: An anonymous survey was sent to the Society of Skeletal Radiology membership querying musculoskeletal radiologists' practice patterns, fellowship program, curriculum, and modes of learning. RESULTS: Of 216 respondents (26% response rate), 87% were musculoskeletal fellowship trained. The majority performed MRI, CT, and radiography (99%); arthrography (95%); spine MRI (77%); pediatric musculoskeletal imaging (75%); musculoskeletal ultrasound (63%); and biopsies (62%). During fellowship, 72% read spine MRI; 74% pediatric musculo-skeletal imaging, and 49% musculoskeletal ultrasound (49%); 33% received no spine procedural training. Most felt comfortable performing arthrography, joint injections, and bone and soft-tissue biopsies but not spine biopsies. Of the total, 33% received a curriculum and 67% had no formal feedback and 56% did not evaluate their program. The highest rated program features were teaching by attending physicians (69%), case variety (54%), and procedural training (49%). The lowest rated features were lack of curriculum (57%), lack of structured learning (48%), and lack of mentoring (24%). The favorite mode of learning was one-on-one readout with attending physicians (90%), and 85% agreed that a standardized musculoskeletal fellowship curriculum would benefit musculoskeletal training. CONCLUSION: Although musculoskeletal radiologists believe they were adequately trained for practice, there are perceived deficiencies in spine MRI, pediatric musculoskeletal imaging, and musculoskeletal ultrasound. A standardized musculoskeletal fellowship curriculum would provide improved structure and a defined educational program. Clear expectations, performance assessment, feedback, and programmatic evaluation should be core elements of the training of every musculoskeletal fellow.

On-call musculoskeletal radiographs: discrepancy rates between radiology residents and musculoskeletal radiologists.

OBJECTIVE: The purpose of this study was to determine the rate of discrepancy between radiology residents and attending musculoskeletal radiologists in interpretation of on-call musculoskeletal radiographs. MATERIALS AND METHODS: We performed a retrospective review of 2219 consecutive musculoskeletal radiology reports on patients who visited the emergency department between January 2009 and December 2010. The images were initially interpreted overnight by on-call residents (postgraduate years 3-5), and a final interpretation was rendered the next morning by a musculoskeletal radiologist. The reports were evaluated for major discrepancies, such as missed fractures, osteomyelitis, foreign bodies, tumors, and acute arthritic conditions, which were defined as cases in which a change in clinical management was needed and required notification of the emergency care provider. RESULTS: The overall discrepancy rate was 1.8% (40/2219). Fractures accounted for 62.5% (25/40) of missed findings. Fractures involving the upper extremity, particularly the hand and wrist (2.2% [9/405]), were the most frequently missed. Radial fractures accounted for 50% (7/14) of the missed upper extremity fractures. Foreign bodies (10% [4/40]) and tumorlike lesions (7.5% [3/40]) accounted for the next most common misses. Finally, independent resident readings in the on-call setting had little adverse effect on patient care. CONCLUSION: In the on-call setting, the low discrepancy rate between interpretations of musculoskeletal radiographs by residents and by musculoskeletal attending radiologists is comparable to that reported for other body parts and modalities. Residents should be aware of the relatively high rate of missed pathologic findings in the upper extremity, especially the radius.

Image guided core needle biopsy of musculoskeletal lesions: are nondiagnostic results clinically useful?

BACKGROUND: The clinical utility of nondiagnostic core needle biopsies is not fully understood. Understanding the clinical and radiologic factors associated with nondiagnostic core needle biopsies may help determine the utility of these nondiagnostic biopsies and guide clinical decision making. QUESTIONS/PURPOSES: We asked (1) whether benign or malignant bone and soft tissue lesions have a higher rate of nondiagnostic core needle biopsy results, and which diagnoses have the lowest diagnostic yield; (2) how often nondiagnostic results affected clinical decision-making; and (3) what clinical factors are associated with nondiagnostic but useful core needle biopsies. METHODS: A retrospective study was performed of 778 consecutive image-guided core needle biopsies of bone and soft tissue lesions referred to the musculoskeletal radiology department at a single institution. The reference standard was (1) the final diagnosis at surgery or (2) clinical followup. Diagnostic yield was calculated for the most common diagnoses. Clinical and imaging features related to each nondiagnostic core needle biopsy were assessed for their association with clinical usefulness. Useful nondiagnostic biopsies were defined as those that help guide treatment. Each lesion was assessed before biopsy by the orthopaedic oncologist as (1) "likely to be benign" or (2) "suspicious for malignancy." The overall diagnostic yield was 74%. RESULTS: Malignant lesions had higher diagnostic yield than benign lesions: 94% (323 of 345) versus 58% (252 of 433), yielding a relative risk (RR) of 1.61 and 95% CI of 1.48 to 1.75. Soft tissue lesions had a higher diagnostic yield than bone lesions: 82% (291 of 355) versus 67% (284 of 423); RR, 1.22; 95% CI, 1.22 (1.12-1.33). Ganglion cyst (36%, four of 11), myositis ossificans (40%, two of five), Langerhans cell histiocytosis (0%, 0 of four), and simple bone cyst 0%, 0 of six) had the lowest diagnostic yield. Of the nondiagnostic biopsies assessed for clinical usefulness by the orthopaedic oncologist, 60% (85 of 142) of the biopsies were useful in guiding clinical decision making. Useful nondiagnostic core needle biopsy results occurred more often in painless, nonaggressive lesions, assessed as "likely to be benign" before biopsy. CONCLUSIONS: Nondiagnostic core needle biopsy results in musculoskeletal lesions are not entirely useless. At times, they can be supportive of benign processes and can help avert unnecessary surgical procedures.

High-resolution proton density weighted three-dimensional fast spin echo (3D-FSE) of the knee with IDEAL at 1.5 Tesla: comparison with 3D-FSE and 2D-FSE--initial experience.

PURPOSE: To assess the feasibility of combining three-dimensional fast spin echo (3D-FSE) and Iterative-decomposition-of water-and-fat-with-echo asymmetry-and-least-squares-estimation (IDEAL) at 1.5 Tesla (T), generating a high-resolution 3D isotropic proton density-weighted image set with and without "fat-suppression" (FS) in a single acquisition, and to compare with 2D-FSE and 3D-FSE (without IDEAL). MATERIALS AND METHODS: Ten asymptomatic volunteers prospectively underwent sagittal 3D-FSE-IDEAL, 3D-FSE, and 2D-FSE sequences at 1.5T (slice thickness [ST]: 0.8 mm, 0.8 mm, and 3.5 mm, respectively). 3D-FSE and 2D-FSE were repeated with frequency-selective FS. Fluid, cartilage, and muscle signal-to-noise ratio (SNR) and fluid-cartilage contrast-to-noise ratio (CNR) were compared among sequences. Three blinded reviewers independently scored quality of menisci/cartilage depiction for all sequences. "Fat-suppression" was qualitatively scored and compared among sequences. RESULTS: 3D-FSE-IDEAL fluid-cartilage CNR was higher than in 2D-FSE (P < 0.05), not different from 3D-FSE (P = 0.31). There was no significant difference in fluid SNR among sequences. 2D-FSE cartilage SNR was higher than in 3D FSE-IDEAL (P < 0.05), not different to 3D-FSE (P = 0.059). 2D-FSE muscle SNR was higher than in 3D-FSE-IDEAL (P < 0.05) and 3D-FSE (P < 0.05). Good or excellent depiction of menisci/cartilage was achieved using 3D-FSE-IDEAL in the acquired sagittal and reformatted planes. Excellent, homogeneous "fat-suppression" was achieved using 3D-FSE-IDEAL, superior to FS-3D-FSE and FS-2D-FSE (P < 0.05). CONCLUSION: 3D FSE-IDEAL is a feasible approach to acquire multiplanar images of diagnostic quality, both with and without homogeneous "fat-suppression" from a single acquisition.

Clavicle and acromioclavicular joint injuries: a review of imaging, treatment, and complications.

Fractures of the clavicle account for 2.6-5% of all fractures. Clavicular fractures have traditionally been treated conservatively, however, there has recently been increased interest in surgical repair of displaced clavicular fractures, with resultant lower rates of nonunion and malunion. Treatment of acromioclavicular (AC) separation has traditionally been conservative, with surgery reserved for patients with chronic pain or significant dislocation and acute soft tissue injury. It is important for the radiologist to become familiar with the surgical techniques used to fixate these fractures as well as the post-operative appearance and potential complications.

Soft-tissue tumors and tumorlike lesions: a systematic imaging approach.

Soft-tissue lesions are frequently encountered by radiologists in everyday clinical practice. Characterization of these soft-tissue lesions remains problematic, despite advances in imaging. By systematically using clinical history, lesion location, mineralization on radiographs, and signal intensity characteristics on magnetic resonance images, one can (a) determine the diagnosis for the subset of determinate lesions that have characteristic clinical and imaging features and (b) narrow the differential diagnosis for lesions that demonstrate indeterminate characteristics. If a lesion cannot be characterized as a benign entity, the lesion should be reported as indeterminate, and the patient should undergo biopsy to exclude malignancy.

Case report: Longitudinal stress fracture of the humerus: imaging features and pitfalls.

Longitudinal stress fractures are an uncommon injury in which a diaphyseal fracture line occurs parallel to the long axis of a bone in the absence of direct trauma. They have been described in the tibia and less commonly in the femur but apparently not in the upper limb. We report a longitudinal stress fracture occurring in the humerus of a 62-year-old woman who had a history of osteoporosis and had undergone recent surgery of the contralateral wrist. We present the radiographic, MRI, and CT features of the case and emphasize the difficulties in diagnosis caused by negative findings on early radiographs and by nonspecific bone marrow edema pattern on MRI. The risk of a contralateral upper extremity stress fracture from activities of daily living in a patient with osteoporosis whose other upper extremity is immobilized also is highlighted.

Bone and soft-tissue lesions: what factors affect diagnostic yield of image-guided core-needle biopsy?

PURPOSE: To assess lesion-related and technical factors that affect diagnostic yield in image-guided core-needle biopsy (CNB) of bone and soft-tissue lesions. MATERIALS AND METHODS: Institutional review board approval and verbal informed consent were obtained for a HIPAA-compliant prospective study of 151 consecutive CNBs of bone (n = 88) and soft-tissue (n = 63) lesions. Each CNB specimen was reported separately in the final pathology report. Diagnostic yield (total number of biopsies that yield a diagnosis divided by total number of biopsies) was calculated for all lesions and subgroups on the basis of lesion composition (lytic, sclerotic, soft tissue), lesion size (< or = 2, > 2 to 5, or > 5 cm), biopsy needle gauge, image guidance modality, number of specimens obtained, and specimen length (< 5, 5-10, or > 10 mm). The minimum number of specimens required to obtain a diagnosis was determined on the basis of the specimen number at which the diagnostic yield reached a plateau. Chi(2) And Wilcoxon rank-sum tests were performed in bivariate analyses to evaluate associations between each factor and diagnostic yield. Significant factors were evaluated with multivariate logistic regression. RESULTS: Diagnostic yield was 77% for all lesions. Yield was 87% for lytic bone lesions and 57% for sclerotic bone lesions (P = .002). Diagnostic yield increased with larger lesions (54% for lesions < or = 2 cm, 75% for lesions > 2 to 5 cm, and 86% for lesions > 5 cm [P = .006]). There was no difference in diagnostic yield for bone versus soft-tissue lesions or according to needle gauge or image guidance modality. Diagnostic yield was 77% for bone lesions and 76% for soft-tissue lesions (P = .88). Yield was 83%, 72%, 77%, and 83% for biopsies performed with 14-, 15-, 16-, and 18-gauge needles, respectively (P = .57). Yield was 77% with computed tomographic guidance and 78% with ultrasonographic guidance (P = .99). Diagnostic yield increased with number of specimens obtained and with longer specimen length; it reached a plateau at three specimens for bone lesions and four specimens for soft-tissue lesions. CONCLUSION: Diagnostic yield is higher in lytic than in sclerotic bone lesions, in larger lesions, and for longer specimens. Obtaining a minimum of three specimens in bone lesions and four specimens in soft-tissue lesions optimizes diagnostic yield.

Anatomical axes of the proximal and distal halves of the femur in a normally aligned healthy population: implications for surgery.

BACKGROUND: The anatomical axis of the femur is crucial for determining the correct alignment in corrective osteotomies of the knee, total knee arthroplasty (TKA), and retrograde and antegrade femoral intramedullary nailing (IMN). The aim of this study was to propose the concept of different anatomical axes for the proximal and distal parts of the femur; compare these axes in normally aligned subjects and also to propose the clinical application of these axes. METHODS: In this cross-sectional study, the horizontal distances between the anatomical axis of the proximal and distal halves of the femur and the center of the intercondylar notch were measured in 100 normally aligned femurs using standard full length alignment view X-rays. RESULTS: The average age was 34.44 ± 11.14 years. The average distance from the proximal anatomical axis to the center of the intercondylar notch was 6.68 ± 5.23 mm. The proximal anatomical axis of femur passed lateral to the center of the intercondylar notch in 12 cases (12%), medial in 84 cases (84%) and exactly central in 4 cases (4%). The average distance from the distal anatomical axis to the center of the intercondylar notch was 3.63 ± 2.09 mm. The distal anatomical axis of the femur passed medially to the center of the intercondylar notch in 82 cases (82%) and exactly central in 18 cases (18%). There was a significant difference between the anatomical axis of the proximal and distal parts of the femur in reference to the center of intercondylar notch (P value < 0.05), supporting the hypothesis that anatomical axes of the proximal and distal halves of the femur are different in the coronal plane. CONCLUSIONS: While surgeons are aware that the anatomical axis of the distal part of the femur is different than the anatomical axis of the proximal part in patients with femoral deformities, we have shown that these axes are also different in the normally aligned healthy people due to the anatomy of the femur in coronal plane. Also the normal ranges provided here can be used as a reference for the alignment guide entry point in TKA and antegrade and retrograde intramedullary femoral nailing.

MR Imaging of Common Soft Tissue Masses in the Foot and Ankle.

Soft tissue masses may be encountered in the foot and ankle and may represent true neoplasms, malignant or benign, or other, nonneoplastic entities that mimic musculoskeletal tumors. This article reviews common soft tissue masses encountered in the foot or ankle, highlights their MR imaging appearance, and outlines common pitfalls. Technical considerations for imaging soft tissue masses in the foot and ankle are discussed. On MR imaging, T1-weighted and T2-weighted signal intensity, contrast enhancement characteristics, and lesion location, together with patient demographics, history and physical examination, and findings on radiographs, can be useful in characterizing masses in the foot and ankle.

Accuracy and Measurement Error of the Medial Clear Space of the Ankle.

BACKGROUND: Measurement of the medial clear space (MCS) is commonly used to assess deltoid ligament competency and mortise stability when managing ankle fractures. Lacking knowledge of the true anatomic width measured, previous studies have been unable to measure accuracy of measurement. The purpose of this study was to determine MCS measurement error and accuracy and any influencing factors. METHODS: Using 3 normal transtibial ankle cadaver specimens, deltoid and syndesmotic ligaments were transected and the mortise widened and affixed at a width of 6 mm (specimen 1) and 4 mm (specimen 2). The mortise was left intact in specimen 3. Radiographs were obtained of each cadaver at varying degrees of rotation. Radiographs were randomized, and providers measured the MCS using a standardized technique. RESULTS: Lack of accuracy as well as lack of precision in measurement of the medial clear space compared to a known anatomic value was present for all 3 specimens tested. There were no significant differences in mean delta with regard to level of training for specimens 1 and 2; however, with specimen 3, staff physicians showed increased measurement accuracy compared with trainees. CONCLUSION: Accuracy and precision of MCS measurements are poor. Provider experience did not appear to influence accuracy and precision of measurements for the displaced mortise. CLINICAL RELEVANCE: This high degree of measurement error and lack of precision should be considered when deciding treatment options based on MCS measurements.

ACR Appropriateness Criteria® Imaging After Total Knee Arthroplasty.

Total knee arthroplasty (TKA) is the most commonly performed joint replacement procedure in the United States and annual demand for primary TKA is expected to grow by 673% by 2030. The first part provides an overview of imaging modalities (radiographs, CT, MRI, ultrasound, and various nuclear medicine studies) and discusses their usefulness in the imaging evaluation of TKA. The second part focuses on evidence-based imaging and imaging-guided intervention algorithms for the workup of TKA and its complications, including routine follow-up, component wear, periprosthetic infection, aseptic loosening, granulomas/osteolysis, conventional and rotational instability, periprosthetic fracture, patellar complications, and a variety of periprosthetic soft tissue abnormalities. 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.