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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.

Osteoporosis is a considerable public health risk, with 50% of women and 20% of men >50 years of age experiencing fracture, with mortality rates of 20% within the first year. Dual x-ray absorptiometry (DXA) is the primary diagnostic modality by which to screen women >65 years of age and men >70 years of age for osteoporosis. In postmenopausal women

Stress fractures, including both fatigue and insufficiency types, are frequently encountered in clinical practice as a source of pain in both athletes and patients with predisposing conditions. Radiography is the imaging modality of choice for baseline diagnosis. MRI has greatly improved our ability to diagnose radiographically occult stress fractures. Tc-99m bone scan and CT may also be useful as diagnostic tools. Although fatigue and insufficiency fractures can be self-limited and go onto healing even without diagnosis, there is usually value in initiating prompt therapeutic measures as incomplete stress fractures have the potential of progressing to completion and requiring more invasive treatment or delay in return to activity. This is particularly important in the setting of stress fractures of the femoral neck. Accuracy in the identification of these injuries is also relevant because the differential diagnosis includes entities that would otherwise be treated significantly different (ie, osteoid osteoma, osteomyelitis, and metastasis). 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.

Evaluation for suspected inflammatory arthritis as a cause for chronic extremity joint pain often relies on imaging. This review first discusses the characteristic osseous and soft tissue abnormalities seen with inflammatory arthritis and how they may be imaged. It is essential that imaging results are interpreted in the context of clinical and serologic results to add specificity as there is significant overlap of imaging findings among the various types of arthritis. This review provides recommendations for imaging evaluation of specific types of inflammatory arthritis, including rheumatoid arthritis, seronegative spondyloarthropathy, gout, calcium pyrophosphate dihydrate disease (or pseudogout), and erosive osteoarthritis. 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.

Chronic hip pain is a common clinical problem whose cause is often elucidated by imaging. The ACR Appropriateness Criteria for chronic hip pain define best practices of image ordering. Clinical scenarios are followed by the imaging choices and their appropriateness. The information is in ordered tables with an accompanying narrative explanation to guide physicians to order the right test. 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.

There has been a rapid increase in the number of shoulder arthroplasties, including partial or complete humeral head resurfacing, hemiarthroplasty, total shoulder arthroplasty, and reverse total shoulder arthroplasty, performed in the United States over the past two decades. Imaging can play an important role in diagnosing the complications that can occur in the setting of these shoulder arthroplasties. This review is divided into two parts. The first part provides a general discussion of various imaging modalities, comprising radiography, CT, MRI, ultrasound, and nuclear medicine, and their role in providing useful, treatment-guiding information. The second part focuses on the most appropriate imaging algorithms for shoulder arthroplasty complications such as aseptic loosening, infection, fracture, rotator cuff tendon tear, and nerve injury. The evidence-based ACR Appropriateness Criteria guidelines offered in this report were reached via an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (the RAND/UCLA Appropriateness Method and the Grading of Recommendations Assessment, Development, and Evaluation) for rating the appropriateness of imaging and treatment procedures for specific clinical scenarios. Further analysis and review of the guidelines were performed by a multidisciplinary expert panel. In those instances in which there was insufficient or equivocal data for recommending the appropriate imaging algorithm, expert opinion may have supplemented the available evidence.

Osteonecrosis of the hip (Legg-Calve-Perthes) is a common disease, with 10,000-20,000 symptomatic cases annually in the United States. The disorder affects both adults and children and is most frequently associated with trauma and corticosteroid usage. The initial imaging evaluation of suspected hip osteonecrosis is done using radiography. MRI is the most sensitive and specific imaging modality for diagnosis of osteonecrosis of the hip. The clinical significance of hip osteonecrosis is dependent on its potential for articular collapse. The likelihood of articular collapse is significantly increased with involvement of greater than 30%-50% of the femoral head area, which is optimally evaluated by MRI, often in the sagittal plane. Contrast-enhanced MRI may be needed to detect early osteonecrosis of the hip in pediatric patients, revealing hypoperfusion. In patients with a contraindication for MRI, use of either CT or bone scintigraphy with SPECT (single-photon emission CT) are alternative radiologic methods of assessment. Imaging helps guide treatment, which may include core decompression, osteotomy, and ultimately, need for joint replacement. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

We report a case of a 53 year old female who presented with a painless mass over her left greater trochanter. Evaluation with MRI and ultimately biopsy led to a diagnosis of fat necrosis. If this diagnosis had been considered with greater confidence, a conservative approach could have been taken and biopsy avoided. In patients with lesions demonstrating classic locations and imaging features of fat necrosis, observation without biopsy is appropriate.

We report the case of a 31-year-old male whose initial imaging presentation was considered highly suspicious for an edematous accessory muscle, the anconeus epitrochlearis. Operative excision led to the diagnosis of tophaceous gout. If this etiology had been considered earlier in the patient's clinical course, his diagnostic evaluation may have been less involved. When faced with a soft tissue mass in the setting of gout, a soft tissue tophus should always be considered.

Shoulder pain is one of the most common reasons for musculoskeletal-related physician visits. Imaging plays an important role in identifying the specific cause of atraumatic shoulder pain. This review is divided into two parts. The first part provides a general discussion of various imaging modalities (radiographs, arthrography, nuclear medicine, ultrasound, CT, and MRI) and their usefulness in evaluating atraumatic shoulder pain. The second part focuses on the most appropriate imaging algorithms for specific shoulder conditions including: rotator cuff disorders, labral tear/instability, bursitis, adhesive capsulitis, biceps tendon abnormalities, postoperative rotator cuff tears, and neurogenic pain. 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.

Radiographs are indicated as the first imaging test in all patients with chronic wrist pain, regardless of the suspected diagnosis. When radiographs are normal or equivocal, advanced imaging with MRI (without or without intravenous contrast or following arthrography), CT (usually without contrast), and ultrasound each has a role in establishing a diagnosis. Furthermore, these examinations may contribute to staging disease, treatment planning, and prognostication, even when radiographs are diagnostic of a specific condition. Which examination or examinations are best depends on the specific location of pain and the clinically suspected conditions. 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.

Analysis of joint fluid remains a key factor in the diagnosis of periprosthetic infection. Recent reports have shown that neutrophils in infected joint fluid release esterase, an enzyme that is a reliable marker for infection. Testing for leukocyte esterase is routinely done in the analysis of urine for the presence of urinary tract infection, by a simple “dipstick” method. We report our experience with this technique in the evaluation of patients suspected of having septic arthritis or periprosthetic joint infection (PJI) by comparing results of leukocyte esterase positivity with confirmed joint infection as defined by the American Academy of Orthopaedic Surgeons (AAOS). We retrospectively reviewed leukocyte esterase test results performed on synovial fluid aspirated from 57 patients with prosthetic (52) and native (5) joints. Patients either presented with unexplained painful arthroplasties, routine testing of PROSTALAC (PROSthesis with Antibiotic-Loaded Acrylic Cement) orthopedic implants, or clinical suspicion of periprosthetic infection or septic arthritis. Synovial fluid was percutaneously aspirated using a standard technique. The patient age range was 31–91 years with a mean age of 69.1 years, consisting of 30 women (52.6 %) and 27 men (47.4 %). The “gold standard” for the presence or absence of infection at our institution and in the study group was based on the most recent recommendations of the AAOS. Positive culture remained the “gold standard” for native joint infection. Of the total 57 joints aspirated and included in the study, 20 (35.1 %) were read as positive (2+) on the leukocyte test strip and 37 (64.9 %) were read as negative (negative, trace, or 1+). PJI was diagnosed in 19 patients and native joint septic arthritis was identified in one patient. Sensitivities were excellent at 100 % with no false negatives in the entire cohort. There was one false positive in the periprosthetic group yielding a specificity, positive predictive value and negative predictive value of 97, 95, and 100 %, respectively. The results for the native joints showed markedly less specificity and positive predictive value at 50 and 33 %; however, its negative predictive value remained at 100 %. Our test results confirm that the leukocyte esterase test can accurately detect PJI and that it can be used as a part of the traditional PJI workup. In the assessment of native joints, its high negative predictive value suggests that it is a valuable tool in excluding native joint septic arthritis.

Effective quality improvement (QI) education should improve patient care, but many curriculum studies do not include clinical measures. The research team evaluated the prevalence of QI curricula with clinical measures and their association with several curricular features. MEDLINE, Embase, CINAHL, and ERIC were searched through December 31, 2013. Study selection and data extraction were completed by pairs of reviewers. Of 99 included studies, 11% were randomized, and 53% evaluated clinically relevant measures; 85% were from the United States. The team found that 49% targeted 2 or more health professions, 80% required a QI project, and 65% included coaching. Studies involving interprofessional learners (odds ratio [OR] = 6.55; 95% confidence interval [CI] = 2.71-15.82), QI projects (OR = 13.60; 95% CI = 2.92-63.29), or coaching (OR = 4.38; 95% CI = 1.79-10.74) were more likely to report clinical measures. A little more than half of the published QI curricula studies included clinical measures; they were more likely to include interprofessional learners, QI projects, and coaching.

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.

Stress fractures, including both fatigue and insufficiency types, are frequently encountered in clinical practice as a source of pain in both athletes and patients with predisposing conditions. Radiography is the imaging modality of choice for baseline diagnosis. MRI has greatly improved our ability to diagnose radiographically occult stress fractures. Tc-99m bone scan and CT may also be useful as diagnostic tools. Although fatigue and insufficiency fractures can be self-limited and go onto healing even without diagnosis, there is usually value in initiating prompt therapeutic measures as incomplete stress fractures have the potential of progressing to completion and requiring more invasive treatment or delay in return to activity. This is particularly important in the setting of stress fractures of the femoral neck. Accuracy in the identification of these injuries is also relevant because the differential diagnosis includes entities that would otherwise be treated significantly different (ie, osteoid osteoma, osteomyelitis, and metastasis). 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.

Osteoporosis is a considerable public health risk, with 50% of women and 20% of men50 years of age experiencing fracture, with mortality rates of 20% within the first year. Dual x-ray absorptiometry (DXA) is the primary diagnostic modality by which to screen women65 years of age and men70 years of age for osteoporosis. In postmenopausal women65 years of age with additional risk factors for fracture, DXA is recommended. Some patients with bone mineral density above the threshold for treatment may qualify for treatment on the basis of vertebral body fractures detected through a vertebral fracture assessment scan, a lateral spine equivalent generated from a commercial DXA machine. Quantitative CT is useful in patients with advanced degenerative bony changes in their spines. New technologies such as trabecular bone score represent an emerging role for qualitative assessment of bone in clinical practice. It is critical that both radiologists and referring providers consider osteoporosis in their patients, thereby reducing substantial morbidity, mortality, and cost to the health care system. 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.

We report the incidental discovery of a flexor carpi radialis brevis tendon, a rare anatomical variant identified during a surgical procedure. Magnetic resonance imaging of the contralateral side helped to delineate the anatomy of the flexor carpi radialis tendon and to differentiate the flexor carpi radialis brevis tendon from it. We describe the use of this rare tendon in ligament reconstruction of the basal joint of the thumb.

Percutaneous synovial biopsy has recently been reported to have a high diagnostic value in the preoperative identification of periprosthetic infection of the hip. We report our experience with this technique in the evaluation of patients undergoing revision hip arthroplasty, comparing results of preoperative synovial biopsy with joint aspiration in identifying an infected hip arthroplasty by bacteriological analysis. We retrospectively reviewed the results of the 110 most recent revision hip arthroplasties in which preoperative synovial biopsy and joint aspiration were both performed. Revision surgery for these patients occurred during the period from September 2005 to March 2012. Using this study group, results from preoperative cultures were compared with preoperative laboratory studies and the results of intraoperative cultures. Synovial aspiration was done using an 18- or 20-gauge spinal needle. Synovial biopsy was done coaxially following aspiration using a 22-gauge Chiba needle or 21-gauge Sure-Cut needle. Standard microbiological analysis was performed on preoperative synovial fluid aspirate and synovial biopsy. Intraoperative tissue biopsy bacteriological analysis results at surgical revision were accepted as the “gold standard” for the presence or absence of infection. Seventeen of 110 (15 %) of patients had intraoperative culture-positive periprosthetic infection. Of these 17 cases, there were ten cases where either the synovial fluid aspiration and/or the synovial biopsy were true positive (sensitivity of 59 %, specificity of 100 %, positive predictive value of 100 % and accuracy of 94 %). There were seven cases where aspiration and biopsy results were both falsely negative, but no false-positive results. Similar results were found for synovial fluid aspiration alone. The results of synovial biopsy alone resulted in the identification of seven infected joints with no false-positive result (sensitivity of 41 %, specificity of 100 %, positive predictive value of 100 %, and accuracy of 91 %). Standard microbiological analyses performed on percutaneous synovial biopsy specimen during the preoperative evaluation of patients undergoing revision hip arthroplasty did not improve detection of culture-positive periprosthetic infection as compared to synovial fluid aspiration alone.

Malrotation of the tibial component is associated with poor outcomes after total knee arthroplasty, yet the definition and evaluation of this problem remain controversial. Contributing factors to this controversy include inconsistent and cumbersome methods for measuring rotation, based upon transposed measurements from multiple computed tomography images. We developed and tested the reliability of a new, simple method for measuring tibial component rotation based upon a single, three-dimensional high definition, axial computed tomography image. Sixty individual knees after total knee arthroplasty were evaluated. The intra-reliability and inter-reliability both exceeded 0.9 whether the tibial component was made of titanium, cobalt–chrome or all-polyethylene. Based upon these findings we suggest that this technique be used for evaluating tibial component rotation in future studies.

Rationale and Objectives At the authors’ institutions, faculty members and trainees work at multiple sites scattered miles apart, making it difficult to physically attend weekly teaching conferences. As a possible solution, a weekly online musculoskeletal teaching conference was undertaken. This quickly grew to include multiple other sites around North America. The authors share their experiences to assist other radiologists in organizing similar educational conferences. Materials and Methods The conferences are run using the Citrix GoToMeeting online meeting system. It runs on multiple platforms, including Mac, PC, iPhone, iPad, and Android. Attendees use a wide variety of microphones, sound cards, powered speakers, and webcams. Most users have fast institutional Internet connections, though several attend via slower connections, such as 3G. Results The conference has run successfully for 2 years, with participants logging in from 24 different sites in 18 states, two Canadian provinces, and three countries. About 48 sessions are held each year, with 10 to 15 sites joining the conferences each week and about 10 to 15 cases seen each week. Most attendees are from university medical centers, though several private practice radiologists attend regularly. Screen-sharing quality is superb, with no discernible difference between local and remote slide quality. Audio quality is usually quite good, particularly for those using computer audio. Audio feedback is an occasional problem, but this issue is now more easily addressed. No single time is equally convenient for participants scattered among four to six time zones. However, some sites find the conferences sufficiently valuable to rearrange their afternoon procedure schedules to reduce conflicts with the conferences. The social aspect of visiting weekly with friends and colleagues from afar is highly valued, as are seeing the wide range of pathology from other institutions and the ability to confer with colleagues on difficult cases. The conferences have also spawned several collaborative educational projects, such as an online journal club, a published book of conference cases, and an online musculoskeletal hardware atlas. Conclusions The weekly online musculoskeletal conference described in this report has matured over 2 years from a peculiar experiment to a very popular conference. Cases not seen locally provide enrichment, and attendees gain educational opportunities not otherwise available. Other radiology groups should be able to create and maintain similar conferences.

There are more than 1 million visits to the ER annually in the United States for acute knee trauma. Many of these are twisting injuries in young patients who can walk and bear weight, and emergent radiography is not required. Several clinical decision rules have been devised that can considerably reduce the number of radiographic studies ordered without missing a clinically significant fracture. Although fractures are seen on only 5% of emergency department knee radiographs, 86% of knee fractures result from blunt trauma. In patients with falls or twisting injuries who have focal tenderness, effusion, or inability to bear weight, radiography should be the first imaging study performed. If radiography shows no fracture, MRI is best for evaluating for a suspected meniscal or ligament tear or patellar dislocation. Patients with knee dislocation should undergo radiography and MRI, as well as fluoroscopic angiography, CT angiography, or MR angiography. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Appropriate imaging modalities for the follow-up of malignant or aggressive musculoskeletal tumors include radiography, MRI, CT, (18)F-2-fluoro-2-deoxy-D-glucose PET/CT, (99m)Tc bone scan, and ultrasound. Clinical scenarios reviewed include evaluation for metastatic disease to the lung in low- and high-risk patients, for osseous metastatic disease in asymptomatic and symptomatic patients, for local recurrence of osseous tumors with and without significant hardware present, and for local recurrence of soft tissue tumors. The timing for follow-up of pulmonary metastasis surveillance is also reviewed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

We have observed that osteoid osteomas are frequently surrounded by thin curvilinear or serpiginous low-density grooves in the surrounding bone on CT examinations. We believe that these grooves represent prominent enlarged feeding arterioles, corresponding to recently published histologic findings. This study was performed to assess the sensitivity and specificity of this vascular groove sign for differentiating osteoid osteomas from other radiolucent bone lesions.The study group consisted of 42 patients with pathologically proven osteoid osteomas. The control group included 29 patients with radiolucent bone lesions other than osteoid osteomas. Two readers scored CT examinations of these lesions for the presence of the vascular groove sign, defined as one or more radiolucent linear or serpiginous grooves extending from the periosteal surface of bone down to the radiolucent tumor. Sensitivity and specificity values were calculated for each reader. Positive and negative predictive values, p values, and interobserver agreement values were calculated.The sensitivity of the vascular groove sign for detection of osteoid osteoma was 73.8% for reader 1 and 76.2% for reader 2, specificity was 96.6% for reader 1 and 89.7% for reader 2, positive predictive value was 96.9% for reader 1 and 91.4% for reader 2, and negative predictive value was 71.8% for reader 1 and 72.2% for reader 2. The p value was less than 0.0001 for both readers. The interobserver agreement was very good, with a kappa value of 0.85.The vascular groove sign is a moderately sensitive but highly specific sign for distinguishing osteoid osteomas from other radiolucent bone tumors on CT.

The U.S. National Press has brought to full public discussion concerns regarding the use of medical radiation, specifically x-ray computed tomography (CT), in diagnosis. A need exists for developing methods whereby assurance is given that all diagnostic medical radiation use is properly prescribed, and all patients’ radiation exposure is monitored. The “DICOM Index Tracker©” (DIT) transparently captures desired digital imaging and communications in medicine (DICOM) tags from CT, nuclear imaging equipment, and other DICOM devices across an enterprise. Its initial use is recording, monitoring, and providing automatic alerts to medical professionals of excursions beyond internally determined trigger action levels of radiation. A flexible knowledge base, aware of equipment in use, enables automatic alerts to system administrators of newly identified equipment models or software versions so that DIT can be adapted to the new equipment or software. A dosimetry module accepts mammography breast organ dose, skin air kerma values from XA modalities, exposure indices from computed radiography, etc. upon receipt. The American Association of Physicists in Medicine recommended a methodology for effective dose calculations which are performed with CT units having DICOM structured dose reports. Web interface reporting is provided for accessing the database in real-time. DIT is DICOM-compliant and, thus, is standardized for international comparisons. Automatic alerts currently in use include: email, cell phone text message, and internal pager text messaging. This system extends the utility of DICOM for standardizing the capturing and computing of radiation dose as well as other quality measures.

Received August 26, 2008; accepted after revision November 21, 2008. 1Department of Radiology, Mayo Clinic, 5777 E Mayo Blvd., Phoenix, AZ 85054. Address correspondence to C. C. Roberts (roberts.catherine@mayo.edu). 2Department of Radiology, Mayo Clinic, Rochester, MN. 3Department of Radiology, University of Central Florida, Orlando, FL. 4Department of Diagnostic Radiology, Mayo Clinic, Jacksonville, FL. AJR 2009;193:S42–S45 0361–803X/09/1933–S42 © American Roentgen Ray Society ABSTRACT 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 bites, stings, and their complications.

Four main areas of quality need to be addressed for a complete quality and safety program in radiology: safety, process improvement, professional outcome assessment, and satisfaction. These areas need to be coordinated by individuals who belong to a quality oversight committee. Management of the data can be facilitated by using a quality scorecard that posts relevant data for each operational group within a department. The ultimate goal is a cultural shift in which all departmental workers assume responsibility for quality and safety improvements and behave consistently with the core values of the organization. A road map for thinking about quality and safety issues in radiology allows all of these areas to be tied together. Four main areas of development are required, each demanding a different skill set and approach.

The purpose of our study was to correlate clinically determined joint stability with the degree of bone fusion in the ankle or subtalar joint on MDCT examinations after arthrodesis.We performed a retrospective review of 42 consecutive MDCT examinations from 29 patients. All patients had previously undergone arthrodesis of their ankle or subtalar joints and had persistent or recurrent hindfoot or ankle pain. Two musculoskeletal radiologists examined in consensus sagittal 2-mm-thick reformatted slices, measuring on each image the length of the joint surface and the length of the fused portion of the joint space. The sum of the lengths of the fused segments on all slices was then divided by the sum of the lengths of the joint surfaces to calculate the fusion ratio. For the standard of reference, the medical records were reviewed and operative reports, diagnostic injections, and physical examinations were used to classify the joints as stable or unstable.Twelve clinically unstable joints had fusion ratios of 0-32.8%, whereas 30 clinically stable joints had fusion ratios of 33.2-100%. Using receiver operating characteristic analysis, we selected the cutoff level that maximized Youden's index (the sum of sensitivity and specificity). Using a 33% fusion ratio as the lower limit cutoff for joint stability, the sensitivity was 100%; specificity, 100%; and accuracy, 100%.After arthrodesis of the ankle or subtalar joint, MDCT scans can be used to determine whether that joint is likely to be stable if33% of the joint has visible bone fusion on sagittal MDCT images.

The educational objectives of this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging evaluation of foot and ankle pathology.

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 evaluation of the solitary pulmonary nodule.

Rationale and Objectives Physicians from many specialties perform musculoskeletal biopsy. Using the Medicare database, we sought to determine which specialties represent the physicians who are performing the majority. Materials and Methods Using the CMS physician supplier procedure summary master file for 1996–2003, we extracted all claims for biopsy procedure codes (including marrow aspiration, muscle biopsy, percutaneous bone biopsy, and open surgical biopsy) categorized by provider specialty, and we analyzed procedure volumes. Results Since 1996, the rate of utilization of percutaneous bone biopsy has remained stable. In 2003, marrow aspiration was most commonly performed by hematology/oncology (80,038, 57%), followed by medical oncology (23,428, 17%); radiologists performed 755 (0.5%). Muscle biopsies were predominantly performed by radiologists (4,761, 40%), followed by neurosurgery (591, 5%). Percutaneous bone biopsy was mostly performed by radiologists (14,830, 53%), but orthopedic surgeons, neurosurgeons, and hematology/oncology specialists performed a large minority (6,879, 2,296, and 1,048 respectively; in aggregate, 37%). From 1996 to 2003, radiologists performed 71% more muscle biopsies (2,788 to 4,761) and 60% more percutaneous bone biopsies (9,259 to 14,830). Although most specialties are performing fewer percutaneous bone biopsies (e.g., oncologists: 7,217 to 1,048, −85%), orthopedic surgeons are performing 247% more (1,983 to 6,879) and neurosurgeons are performing 2,343% more (94 to 2,296). Conclusion Excluding marrow aspiration, radiologists perform the majority of percutaneous bone biopsies, and the volume is increasing in the U.S. Medicare population. The overall volume has remained relatively stable from 1996 to 2003; although medical specialties are performing fewer, the volume performed by surgeons is increasing rapidly.

We report a case of a stress fracture of the scapular spine which developed as a late complication of a reverse shoulder arthroplasty. After initially doing well after surgery, our patient developed pain and decreased shoulder function. A nondisplaced scapular spine fracture was noted on radiographs. Because reverse shoulder arthroplasty is a relatively new procedure in this country, radiologists may be unfamiliar with its potential complications. Stress or insufficiency fractures of the scapular spine and acromion are a potential complication of reverse shoulder arthroplasty, due to increased functional demands of the deltoid muscle, which is often combined with deficiency of acromial bone due to rotator cuff arthropathy and osteopenia.

We report a case of a 4-year-old female with Sotos syndrome (cerebral gigantism) whose initial clinical, pathologic, and imaging presentation was considered suspicious for a vascular malformation of her left thigh. Following 17 months of attempted treatment, excision of the supposed vascular malformation was performed. Pathology tests revealed high-grade sarcoma. The delay of diagnosis resulted in an above-the-knee amputation for definitive treatment. If this etiology had been considered earlier in this patient’s clinical course, her treatment could have commenced sooner, and amputation of her leg may have been avoided. While soft-tissue sarcoma arising in childhood is rare, malignancy should be given consideration when evaluating a mass in a young child with characteristic physical examination findings of Sotos syndrome, since these children have an elevated risk of malignancy over the general population.

This ACR Appropriateness Criteria article offers imaging triage guidance for several variants of patients presenting with acute foot trauma. Patients meeting inclusion criteria for the Ottawa Rules should undergo a 3-view radiographic series. Diabetic patients with peripheral neuropathy should undergo radiography, even though they do not meet the Ottawa Rules inclusion criteria. Patients with suspected midfoot and/or Lisfranc injury should undergo 3-view radiographs with weight bearing on at least the anterior-posterior view. Patients with suspected Lisfranc injury and normal radiographs should be considered for MRI and CT on a case-by-case basis. MRI or ultrasound could confirm cases of suspected acute tendon rupture. Radiography is the initial imaging modality for suspected plantar plate injury after metatarsal-phalangeal joint injury. Weight-bearing anterior-posterior, lateral, and sesamoid axial views may detect proximal migration of the hallux sesamoids. Ultrasound or MRI can directly evaluate the capsuloligamentous complex, specifically the plantar plate. Radiography can detect radiopaque penetrating foreign bodies, and ultrasound can be helpful in detecting those that are nonradiopaque. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures, by the panel. In instances in which evidence is lacking or is not definitive, expert opinion may be used to recommend imaging and treatment.

The educational objectives of this self-assessment module are for the participant to exercise, self-assess, and improve his or her knowledge of the imaging evaluation of right lower quadrant pain.

A solid breast mass that decreases in size over time without treatment is generally felt to be inconsistent with a diagnosis of malignancy. We describe a case where this dogma proves to be incorrect. Mammographic features of a mass, along with the patient's clinical hormonal status, need to be considered along with size characteristics.

We report a case of an adolescent female who had an initial outside clinical and imaging presentation that was considered highly suspicious for metastatic osteosarcoma. Extensive evaluation led to the diagnosis of chronic recurrent multifocal osteomyelitis. If this etiology had been considered earlier in the patient's clinical course, her diagnostic evaluation may have been less involved and treatment could have commenced sooner. When this entity is a diagnostic possibility along with neoplasm, strong consideration should be given to proceeding directly to open surgical biopsy due to the difficulty in diagnosing this lesion from small percutaneously-obtained biopsy samples.