Preparing MSK radiologists of the future.

The future will bring increasing demands for specialty training of MSK radiologists. These will include requirements for further standardization of curriculum, educational methods, and documentation. This will place further burdens (both temporal and financial) on the fellowship programs and may lead to termination of some programs. There is a risk that increasingly bureaucratic training requirements may "crowd out" the basic conceptual education necessary for the continued growth and relevance of the subspecialty. Educators must find ways to incorporate these aspects into programs even when they are not mandated.

Malignant pleural mesothelioma characteristics and outcomes: A SEER-Medicare analysis.

BACKGROUND: Pleural mesothelioma is rare cancer linked to asbestos exposure. Previous research has indicated that female individuals have better survival than male individuals, but this has never been examined in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. MATERIALS AND METHODS: Malignant pleural mesothelioma cases diagnosed from 1992 to 2015 were queried from the linked SEER-Medicare database. Multivariable logistic regression was used to assess the clinical and demographic factors associated with sex. A multivariable Cox proportional hazards model and propensity matching methods were used to assess sex differences in overall survival (OS) while accounting for potential confounders. RESULTS: Among 4201 patients included in the analysis, 3340 (79.5%) were males and 861 (20.5%) females. Females were significantly older, with more epithelial histology than males were, and had significantly better OS, adjusted for confounders (adjusted hazard ratio, 0.83, 95% confidence interval: 0.76-0.90). Other variables independently associated with improved survival included younger age at diagnosis, having a spouse/domestic partner, epithelial histology, lower comorbidity score, and receipt of surgery or chemotherapy. CONCLUSIONS: The study describes sex differences in mesothelioma occurrence, treatment, and survival and is the first to examine SEER-Medicare. It provides directions for future research into potential therapeutic targets.

Nerve autofluorescence under near-ultraviolet light: cutting-edge technology for intra-operative neural tissue visualization in 17 patients.

BACKGROUND: Nerve visualization and the identification of other neural tissues during surgery is crucial for numerous reasons, including the prevention of iatrogenic nerve and neural structure injury and facilitation of nerve repair. However, current methods of intra-operative nerve detection are generally expensive, unproven, and/or technically challenging. Recently, we have documented, in both in vivo animal models and ex vivo human tissue, that nerves autofluorescence when viewed in near-ultraviolet light (NUV). In this paper, we describe our use of nerve autofluorescence to facilitate the visualization of nerves and other neural tissues intra-operatively in 17 patients undergoing a range of surgical procedures. METHODS: Employing the same prototype axon imaging system previously documented to markedly enhance nerve visualization in both in vivo animal and ex vivo human models, surgical fields were observed in 17 patients under both white and NUV light during parotid tumor resection (n = 3), thyroid tumor resection (n = 7), and surgery for peripheral nerve and spinal tumors and injury (n = 7). RESULTS: In all 17 patients, the intra-operative use of the imaging system both was feasible and markedly enhanced the localization of all neural tissues throughout their course within the surgical field. All 17 procedures were successful and devoid of any peri-operative complications or post-operative neurological deficits. CONCLUSIONS: Intra-operatively visualizing auto-fluorescent peripheral nerves and other neural tissues under NUV light is feasible in human patients across a range of clinical scenarios and appears to appreciably enhance nerve and other neural tissue visualization. Controlled studies to explore this technology further are needed.

Fracture through tracking pin sites following a robotic-assisted total knee arthroplasty.

The use of computer-navigated, robotic-assisted total knee arthroplasty (TKA) is expanding as the result of widespread efforts to improve the precision of implant placement and to restore mechanical, anatomic, and kinematic alignment. The procedure requires placement of femoral and tibial pins to mount the robotic tracking system. Fractures through tracking pin sites following robotic-assisted TKA are rare; only 30 cases have been reported to our knowledge. It is probable that this complication will become more frequent as the use of robotic-assisted TKAs continues to grow. We report the case of a 67-year-old female who suffered a fracture of the femur through two pin sites 3 months after a robotic-assisted TKA. We believe that this report is the first case in the radiologic literature. Our case demonstrates some of the difficulties of recognizing this complication and raises questions about appropriate post-operative imaging.

Best Practices: CT-Guided Percutaneous Sampling of Vertebral Discitis-Osteomyelitis and Technical Factors Maximizing Biopsy Yield.

Vertebral discitis-osteomyelitis is an infection of the intervertebral disk and vertebral bodies that may extend to adjacent paraspinal and epidural soft tissues. Its incidence is increasing, likely because of improved treatments and increased life expectancy for patients with predisposing chronic disease and increased rates of IV drug use and intravascular intervention. Because blood cultures are frequently negative in patients with vertebral discitis-osteomyelitis, biopsy is often indicated to identify a causative microorganism for targeted antimicrobial therapy. The reported yield of CT-guided percutaneous sampling is 31-91%, which is lower than the reported yield of open biopsy of 76-91%. However, the less invasive approach may be favored given its relative safety and low cost. If paravertebral fluid collections are present, CT-guided aspiration should be performed. If aspiration is unsuccessful or no paravertebral fluid collections are present, CT-guided percutaneous biopsy should be performed, considering technical factors (e.g., anatomic approach, needle selection, and needle angulation) that may improve microbiologic yield. Although antimicrobial therapy should be withheld for 1-2 weeks before biopsy if clinically feasible, biopsy may still be performed without stopping antimicrobial therapy if needed. Because of the importance of targeted antimicrobial therapy, repeat biopsy should be considered after 72 hours if initial biopsy does not identify a pathogen.

Revision surgery in thoracic disc herniation.

PURPOSE: Surgical treatment failures or strategies for the reoperation of residual thoracic disc herniations are sparsely discussed. We investigated factors that led to incomplete disc removal and recommend reoperation strategies. METHODS: As a referral centre for thoracic disc disease, we reviewed retrospectively the clinical records and imaging studies before and after the treatment of patients who were sent to us for revision surgery for thoracic disc herniation from 2013 to 2018. RESULTS: A total of 456 patients were treated from 2013 to 2018 at our institution. Twenty-one patients had undergone previously thoracic discectomy at an outside facility and harboured residual, incompletely excised and symptomatic herniated thoracic discs. In 12 patients (57%), the initial symptoms that led to their primary operation were improved after the first surgery, but recurred after a mean of 2.8 years. In seven patients (33%) they remained stable, and in two cases they were worse. All patients were treated via all dorsal approaches. In all 21 cases, the initial excision was incomplete regarding medullar decompression. All of the discs were removed completely in a single revision procedure. After mean follow-up of 24 months (range 12-57 months), clinical neurological improvement was demonstrated in seven patients, while three patients suffered a worsening and 11 patients remained stable. CONCLUSION: Our data suggest that pure dorsal decompression provides a short relief of the symptoms caused by spinal cord compression. Progressive myelopathy (probably due to mechanical and vascular deficits) and scar formation may cause worsening of symptoms. These slides can be retrieved under Electronic Supplementary Material.

Correction to: Revision surgery in thoracic disc herniation.

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

Osteoblastoma of the clavicle at the site of a previous fracture-first case report and review of the literature.

Osteoblastoma is a rare, benign primary tumor of bone, accounting for < 1% of all bone tumors. We report the case of a 27-year-old female who developed pain and swelling five and a half years after a clavicular fracture and was subsequently found to have an osteoblastoma arising at the fracture site. This is the first reported case of an osteoblastoma developing after a fracture, although osteoid osteomas, which are histologically indistinguishable from osteoblastomas, have been reported at prior fracture sites. This report demonstrates that secondary neoplasms such as osteoblastomas should be considered in the differential diagnosis for pain at a healed fracture site recurring years after the initial trauma.

Utilization Management of High-Cost Imaging in an Outpatient Setting in a Large Stable Patient and Provider Cohort over 7 Years.

Purpose To quantify the effect of a comprehensive, long-term, provider-led utilization management (UM) program on high-cost imaging (computed tomography, magnetic resonance imaging, nuclear imaging, and positron emission tomography) performed on an outpatient basis. Materials and Methods This retrospective, 7-year cohort study included all patients regularly seen by primary care physicians (PCPs) at an urban academic medical center. The main outcome was the number of outpatient high-cost imaging examinations per patient per year ordered by the patient's PCP or by any specialist. The authors determined the probability of a patient undergoing any high-cost imaging procedure during a study year and the number of examinations per patient per year (intensity) in patients who underwent high-cost imaging. Risk-adjusted hierarchical models were used to directly quantify the physician component of variation in probability and intensity of high-cost imaging use, and clinicians were provided with regular comparative feedback on the basis of the results. Observed trends in high-cost imaging use and provider variation were compared with the same measures for outpatient laboratory studies because laboratory use was not subject to UM during this period. Finally, per-member per-year high-cost imaging use data were compared with statewide high-cost imaging use data from a major private payer on the basis of the same claim set. Results The patient cohort steadily increased in size from 88 959 in 2007 to 109 823 in 2013. Overall high-cost imaging utilization went from 0.43 examinations per year in 2007 to 0.34 examinations per year in 2013, a decrease of 21.33% (P < .0001). At the same time, similarly adjusted routine laboratory study utilization decreased by less than half that rate (9.4%, P < .0001). On the basis of unadjusted data, outpatient high-cost imaging utilization in this cohort decreased 28%, compared with a 20% decrease in statewide utilization (P = .0023). Conclusion Analysis of high-cost imaging utilization in a stable cohort of patients cared for by PCPs during a 7-year period showed that comprehensive UM can produce a significant and sustained reduction in risk-adjusted per-patient year outpatient high-cost imaging volume. © RSNA, 2017.

Skeletal Radiology: the year in review 2016.

A look back at Skeletal Radiology in 2016 reveals a sizable number of publications that significantly advanced the state of knowledge about diseases of the musculoskeletal system. This review summarizes the content of some of the most intriguing papers of the year.

Multiple giant cell tumors of bone arising from multiple fatty tumors.

We describe a patient with a history of giant cell tumor who over the course of 18 years developed multiple fat containing osseous lesions in the pelvis and spine. Two of these lesions subsequently evolved into biopsy proven giant cell tumor of bone. To our knowledge, this phenomenon of giant cell tumors evolving from fat containing lesions has not been described.

MR imaging features of hemispherical spondylosclerosis.

OBJECTIVE: Hemispherical spondylosclerosis (HS) is a rare degenerative entity characterized by dome-shaped sclerosis of a single vertebral body that may pose a diagnostic dilemma. The goal of this study was to describe the MR imaging features of HS. MATERIALS AND METHODS: We identified spine radiographs and CT examinations of subjects with HS who also had MR imaging for correlation. Two musculoskeletal radiologists independently assessed sclerosis characteristics, presence of endplate erosions, marrow signal intensity, and disk degeneration (Pfirrmann scale). RESULTS: We identified 11 subjects (six males, five females, mean 48 ± 10 years) with radiographic/CT findings of HS. The most commonly affected vertebral body was L4 (6/11; 55%). On MR imaging, variable signal intensity was noted, being most commonly low on T1 (8/11, 73%) and high on fat-suppressed T2-weighted (8/11, 73%) images. In two subjects, diffuse post-contrast enhancement was seen in the lesion. Moderate disk degeneration and endplate bone erosions adjacent to sclerosis were present in all subjects. Erosions of the opposite endplate were present in two subjects (2/11, 18%). CT data from nine subjects showed the mean attenuation value of HS was 472 ± 96 HU. CONCLUSIONS: HS appearance on MR imaging is variable and may not correlate with the degree of sclerosis seen on radiographs or CT. Disk degenerative changes and asymmetric endplate erosions are consistent markers of HS.

Primary intra-articular sarcoma: a clinicopathological study of 15 cases.

AIMS: To assess the clinical and histopathological spectrum of primary intra-articular sarcomas. METHODS AND RESULTS: Fifteen patients were identified as having primary intra-articular sarcomas and the clinical and pathological features were evaluated. There were nine males and six females who ranged in age from 16 to 84 (mean 44) years. All tumours originated in the knee joint. The pathological diagnoses included: five synovial sarcoma, three extraskeletal myxoid chondrosarcomas, two high-grade myxofibrosarcoma (one conventional, one epithelioid), two undifferentiated pleomorphic sarcoma (one with giant cells) and one each myxoinflammatory fibroblastic sarcoma, conventional hyaline chondrosarcoma, and high-grade myofibroblastic sarcoma. All tumours were treated by segmental resection or amputation. Adjuvant therapy was given in selected cases. Follow-up ranged from 11 to 150 months. Of patients with follow-up, two died of disease; one developed pulmonary metastases after 6 years and was then lost to follow-up. Nine patients were alive and free of disease 12-150 months after diagnosis. CONCLUSIONS: Primary sarcomas of the joints are very rare and most frequently affect the knee. Our experience indicates that synovial sarcoma and extraskeletal myxoid chondrosarcoma are the most common intra-articular sarcomas.

Imaging Findings of Metabolic Bone Disease.

Metabolic bone diseases are a diverse group of diseases that result in abnormalities of (a) bone mass, (b) structure mineral homeostasis, (c) bone turnover, or (d) growth. Osteoporosis, the most common metabolic bone disease, results in generalized loss of bone mass and deterioration in the bone microarchitecture. Impaired chondrocyte development and failure to mineralize growth plate cartilage in rickets lead to widened growth plates and frayed metaphyses at sites of greatest growth. Osteomalacia is the result of impaired mineralization of newly formed osteoid, which leads to characteristic Looser zones. Hypophosphatasia is a congenital condition of impaired bone mineralization with wide phenotypic variability. Findings of hyperparathyroidism are the result of bone resorption, most often manifesting as subperiosteal resorption in the hand. Renal osteodystrophy is the collection of skeletal findings observed in patients with chronic renal failure and associated secondary hyperparathyroidism and can include osteopenia, osteosclerosis, and "rugger jersey spine." Hypoparathyroidism is most commonly due to iatrogenic injury, and radiographic findings of hypoparathyroidism reflect an overall increase in bone mass. Thyroid hormone regulates endochondral bone formation; and congenital hypothyroidism, when untreated, leads to delayed bone age and absent, irregular, or fragmented distal femoral and proximal tibial epiphyses. Soft-tissue proliferation of thyroid acropachy is most often observed in the hands and feet. The findings of acromegaly are due to excess growth hormone secretion and therefore proliferation of the bones and soft tissues. Vitamin C deficiency, or scurvy, impairs posttranslational collagen modification, leading to subperiosteal hemorrhage and fractures. ©RSNA, 2016.

Differences in sex distribution, anatomic location and MR imaging appearance of pediatric compared to adult chordomas.

BACKGROUND: Chordomas are rare malignancies that primarily affect adults, but also rarely affect pediatric patients. We compared the imaging appearance, demographic and anatomic distributions of adult and pediatric chordomas in a large cohort. METHODS: We performed a retrospective review of medical records of 220 subjects with histologically confirmed chordomas of the axial skeleton and pre-treatment magnetic resonance imaging studies. Age, sex, type of chordoma (conventional, chondroid or dedifferentiated), the anatomic location of the chordoma, as well as whether the lesion was primarily extra-osseous were recorded. Pediatric subjects were less than 21 years at the time of diagnosis. Binomial two-sample tests of proportions and Fisher's exact tests were used to compare proportions between the pediatric and adult subjects. RESULTS: Fifty six pediatric subjects (58.9 % female) and 164 adult subjects (42.1 % female) were identified. The proportion of female subjects with chordomas was significantly higher in the pediatric cohort compared to the adult cohort (P = 0.04). Most chordomas occur in Caucasians, however African-Americans were more represented in the pediatric cohort than in the adult cohort (P = 0.01). 69.6 % (39/56) of the pediatric chordomas involved the clivus/skull base and cervical spine compared to 29.3 % (48/164) of the adult chordomas (P = 1.99 × 10(-7)). Only 1.8 % (1/56) of the pediatric chordomas was in the sacrococcygeal region compared to 36.0 % (59/164) of the adult chordomas (P = 2.55 × 10(-8)). In cases where pre-treatment imaging was available, 93.8 % (16/17) of pediatric chordomas were predominantly extra-osseous compared to 76.7 % (46/60) of adult chordomas (P = 0.17). CONCLUSIONS: Pediatric chordomas more often affect females and occur most frequently at the craniocervical junction with decrease in incidence distally in the spine, whereas adult chordomas most frequently involve the craniocervical and sacrococcygeal regions.

Limited magnetic resonance imaging of the lumbar spine has high sensitivity for detection of acute fractures, infection, and malignancy.

OBJECTIVE: The objective of this study is to determine how a limited protocol MR examination compares to a full conventional MR examination for the detection of non-degenerative pathology such as acute fracture, infection, and malignancy. MATERIALS AND METHODS: A sample of 349 non-contrast MR exams was selected retrospectively containing a 3:1:1:1 distribution of negative/degenerative change only, acute fracture, infection, and malignancy. This resulted in an even distribution of pathology and non-pathology. A limited protocol MR exam was simulated by extracting T1-weighted sagittal and T2-weighted fat-saturated (or STIR) sagittal sequences from each exam and submitting them for blinded review by two experienced musculoskeletal radiologists. The exams were evaluated for the presence or absence of non-degenerative pathology. Interpretation of the limited exam was compared to the original report of the full examination. If either reader disagreed with the original report, the case was submitted for an unblinded adjudication process with the participation of a third musculoskeletal radiologist to establish a consensus diagnosis. RESULTS: There were five false negatives for a sensitivity of 96.9 % for the limited protocol MR exam. Infection in the psoas, paraspinal muscles, and sacroiliac joint, as well as acute fractures in transverse processes and sacrum were missed by one or more readers. No cases of malignancy were missed. Overall diagnostic accuracy was 96.0 % (335/349). CONCLUSIONS: MR imaging of the lumbar spine limited to sagittal T1-weighted and sagittal T2 fat-saturated (or STIR) sequences has high sensitivity for the detection of acute fracture, infection, or malignancy compared to a conventional MR examination.

Serially recurrent osteoid osteoma.

Osteoid osteoma is a relatively common, benign, painful tumor of bone. It is widely believed to run a course culminating in spontaneous regression. The tumor can usually be eliminated by excision or ablation, although it may recur locally. Although management has classically been surgical, thermocoagulation via percutaneously delivered radiofrequency energy has demonstrated excellent results, typically resulting in durable response following a single treatment. Here, we present an unusual case of serially recurrent pathologically proven pediatric osteoid osteoma, treated by radiofrequency ablation five times over the course of 11 years. Limitations of RF ablation of osteoid osteoma and possible factors predisposing to incomplete treatment or recurrence are discussed.

Percutaneous CT-guided needle biopsies of musculoskeletal tumors: a 5-year analysis of non-diagnostic biopsies.

OBJECTIVE: To study non-diagnostic CT-guided musculoskeletal biopsies and take steps to minimize them. Specifically we asked: (1) What malignant diagnoses have a higher non-diagnostic rate? (2) What factors of a non-diagnostic biopsy may warrant more aggressive pursuit? (3) Do intra-procedural frozen pathology (FP) or point-of-care (POC) cytology reduce the non-diagnostic biopsy rate? MATERIALS AND METHODS: This study was IRB-approved and HIPAA-compliant. We retrospectively reviewed 963 consecutive CT-guided musculoskeletal biopsies. We categorized pathology results as malignant, benign, or non-diagnostic and recorded use of FP or POC cytology. Initial biopsy indication, final diagnosis, method of obtaining the final diagnosis of non-diagnostic biopsies, age of the patient, and years of biopsy attending experience were recorded. Groups were compared using Pearson's χ(2) test or Fisher's exact test. RESULTS: In all, 140 of 963 (15%) biopsies were non-diagnostic. Lymphoma resulted in more non-diagnostic biopsies (P < 0.0001). While 67% of non-diagnostic biopsies yielded benign diagnoses, 33% yielded malignant diagnoses. Patients whose percutaneous biopsy was indicated due to the clinical context without malignancy history almost always generated benign results (96%). Whereas 56% of biopsies whose indication was an imaging finding of a treatable lesion were malignant, 20% of biopsies whose indication was a history of malignancy were malignant. There was no statistically significant difference in the nondiagnostic biopsy rates of pediatric versus adult patients (P = 0.8) and of biopsy attendings with fewer versus more years of experience (P = 0.5). The non-diagnostic rates of biopsies with FP (8%), POC cytology (25%), or neither (24%) were significantly different (P < 0.0001). CONCLUSION: Lymphoma is the malignant diagnosis most likely to result in a non-diagnostic biopsy. If the clinical and radiologic suspicion for malignancy is high, repeat biopsy is warranted. If the clinical context suggests a benign lesion, a non-diagnostic biopsy may be considered reassuring. Frozen pathology may decrease the non-diagnostic biopsy rate.