Identification of Molecular Pathologies Sufficient to Cause Neuropathic Excitability in Primary Somatosensory Afferents Using Dynamical Systems Theory

Pain caused by nerve injury (i.e. neuropathic pain) is associated with development of neuronal hyperexcitability at several points along the pain pathway. Within primary afferents, numerous injury-induced changes have been identified but it remains unclear which molecular changes are necessary and sufficient to explain cellular hyperexcitability. To investigate this, we built computational models that reproduce the switch from a normal spiking pattern characterized by a single spike at the onset of depolarization to a neuropathic one characterized by repetitive spiking throughout depolarization. Parameter changes that were sufficient to switch the spiking pattern also enabled membrane potential oscillations and bursting, suggesting that all three pathological changes are mechanistically linked. Dynamical analysis confirmed this prediction by showing that excitability changes co-develop when the nonlinear mechanism responsible for spike initiation switches from a quasi-separatrix-crossing to a subcritical Hopf bifurcation. This switch stems from biophysical changes that bias competition between oppositely directed fast- and slow-activating conductances operating at subthreshold potentials. Competition between activation and inactivation of a single conductance can be similarly biased with equivalent consequences for excitability. “Bias” can arise from a multitude of molecular changes occurring alone or in combination; in the latter case, changes can add or offset one another. Thus, our results identify pathological change in the nonlinear interaction between processes affecting spike initiation as the critical determinant of how simple injury-induced changes at the molecular level manifest complex excitability changes at the cellular level. We demonstrate that multiple distinct molecular changes are sufficient to produce neuropathic changes in excitability; however, given that nerve injury elicits numerous molecular changes that may be individually sufficient to alter spike initiation, our results argue that no single molecular change is necessary to produce neuropathic excitability. This deeper understanding of degenerate causal relationships has important implications for how we understand and treat neuropathic pain

ACR Appropriateness Criteria Imaging After Shoulder Arthroplasty

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

Improving radiographic quality at a busy outpatient imaging center

A multidisciplinary task force, including musculoskeletal radiologists and technologist leads, was established to assess and correct the large number of quality defects observed on adult musculoskeletal radiology plain radiographs (x-rays)

ACR Appropriateness Criteria(R) Osteoporosis and Bone Mineral Density

Osteoporosis is a considerable public health risk, with 50% of women and 20% of men \u3e 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 \u3e 65 years of age and men \u3e 70 years of age for osteoporosis. In postmenopausal women 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

Building a Learning Community for Radiology Quality and Safety in Massachusetts: Confronting Challenges and Creating Opportunities

Radiologists in quality and safety (QS) leadership positions often arrive with little to no formal training in QS. Their determination and practical problem-solving skills have allowed them to succeed in local QS initiatives; however, they now must develop and manage practice-wide comprehensive programs and face challenges that typically lack single, straightforward solutions. Resources for QS training and program management offered by professional organizations [1] do not take the place of sharing experiential knowledge that can help resolve dilemmas, support practical implementation, and accelerate change [2,3]. In 2016, we both assumed QS leadership positions at separate tertiary medical centers in Massachusetts and began talking regularly about our QS work. In doing so, we realized QS challenges were similar across institutions and that the peer-to-peer mentorship was valuable. We outline here what we learned from the successes and challenges of scaling our informal mentorship into a formal learning community, The Massachusetts Radiology Quality and Safety Council

ACR Appropriateness Criteria(R) Chronic Hip Pain

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

ACR Appropriateness Criteria(R) Chronic Extremity Joint Pain-Suspected Inflammatory Arthritis

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

Diffuse bone marrow sarcoid-like reaction associated with renal cell carcinoma

Sarcoid-like reaction has been documented in association with several types of malignancy, including renal cell carcinoma. We report the case of a 41-year-old man with nonmetastatic renal cell carcinoma and concomitant non-caseating granulomas distributed diffusely throughout the bone marrow. The granulomas resolved after nephrectomy. As far as we know, this is the first reported case of a sarcoid-like reaction primarily involving the bone marrow in association with renal cell carcinoma

ACR Appropriateness Criteria(R) Stress (Fatigue/Insufficiency) Fracture, Including Sacrum, Excluding Other Vertebrae

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

Improving the Transcription of Patient Information From Image Requisitions to the Radiology Information System

PURPOSE: The purpose of this study was to improve the transcription of patient information from imaging study requisitions to the radiology information database at a single institution. METHODS: Five hundred radiology reports from adult outpatient radiographic examinations were chosen randomly from the radiology information system (RIS) and categorized according to their degree of concordance with their corresponding clinical order indications. The number and types of grammatical errors and types of order forms were also recorded. Countermeasures centered on the education of the technical staff and referring physician offices and the implementation of a checklist. Another sample of 500 reports was taken after the implementation of the countermeasures and compared with the baseline data using a chi2 test. RESULTS: The number of RIS indications perfectly concordant with their corresponding clinical order indications increased from 232 (46.4%) to 314 (62.8%) after the implementation of the countermeasures (P \u3c .0001). The number of partially concordant matches due to inadequate RIS indications dropped from 162 (32.4%) to 114 (22.8%) (P \u3c .001), whereas the number of partially concordant matches due to inadequate clinical order indications increased from 22 (4.4%) to 57 (11.4%) (P \u3c .0001). The number of discordant pairings dropped from 84 (16.8%) to 15 (3%) (P \u3c .0001). Technologists began to input additional patient information obtained from the patients (not present in the image requisitions) in the RIS after the implementation of the countermeasures. CONCLUSIONS: The education of technical staff members and the implementation of a checklist markedly improved the information provided to radiologists on image requisitions from referring providers