Assessing tophaceous spinal gout treatment response using dual-energy CT as a point-of-care imaging modality: case report.

We describe a case of chronic tophaceous gout affecting the spine, hands, elbows, feet, and knees in a 67-year-old man with serum urate levels at 549 µmol/L whose response to treatment was successfully mapped using dual-energy computed tomography (DECT). The patient presented with exacerbation of acute-on-chronic lumbar back pain. He had received a diagnosis of gout 3 years prior to this presentation yet was not on any urate-lowering therapy. The patient received febuxostat 80 mg and colchicine 0.3 mg once daily and underwent DECT to assess baseline monosodium urate (MSU) burden. At baseline, MSU deposits were seen in the hands, elbows, feet, knees, and lumbar spine including the left L5-S1 facet joint encroaching onto the neural foramen. After 2.5 years of treatment, serum urate level was within the target range (< 360 µmol/L), and the patient underwent a follow-up DECT that revealed almost full resolution of MSU deposition in the spine, including the MSU-burdened facet joint and neural foramen in the lumbar spine, in addition to all the affected peripheral joints. This case is the first report of radiological evidence of nearly complete resolution of MSU deposits in spinal gout on DECT after urate-lowering therapy treatment, which demonstrates the utility of this imaging modality as a non-invasive investigational point-of-care imaging modality for mapping treatment response and identifying the etiology of back pain in a patient with chronic tophaceous spinal gout.

A Comprehensive Radiologic Review of Shoulder Girdle Trauma.

Radiologic knowledge of different fracture patterns involving the shoulder girdle is an important tool to generate clinically relevant reports, identify concomitant injuries, guide management decisions, and predict and minimize complications, such as nonunion, osteoarthritis, osteonecrosis, and hardware failure. Complex unstable injuries like scapulothoracic dissociation can also occur because of shoulder girdle trauma. Management options may vary from conservative to surgical, depending on the fracture type and patient factors. Injuries around the shoulder girdle can involve the glenohumeral articulation, scapula, superior shoulder suspensory complex, acromioclavicular joints, and scapulothoracic articulation.

Imaging Review of Hockey-Related Upper Extremity Injuries.

Ice hockey is a fast-paced contact sport with a high incidence of injuries. Upper extremity injury is one of the most common regions of the body to be injured in hockey. This imaging review will equip the radiologist with a knowledge of the more common and severe upper extremity injuries that occur in this sport.

Imaging Review of Hockey-related Lower Extremity Injuries.

Hockey is a fast-paced contact sport with a high incidence of injuries. Although injuries are more frequent among elite players, recreational hockey injuries are a common issue faced by primary care and emergency physicians. Lower extremity injuries in hockey are particularly important because they account for approximately a third of all injuries and > 60% of all overuse injuries. This pictorial review provides the general and specialty trained radiologist with a knowledge of the patterns of lower extremity injury that occur in ice hockey.

Imaging of Hockey-related Injuries of the Head, Neck, and Body.

Hockey is a demanding contact sport with growing popularity around the world. This article is part of a review series in this issue of Seminars in Musculoskeletal Radiology that summarizes epidemiological research on the patterns of ice hockey injuries as well as provides pictorial examples for a radiologist's perspective. We focus on non-extremity pathologies which encompass many of the most devastating injuries of hockey, namely those involving the head, neck, face, spine, and body.

Repetitive trauma-induced extra-nuchal-type fibroma.

A nuchal-type fibroma is a rare, benign fibrous tumour that typically occurs in the posterior neck along the midline, but can occur in extra-nuchal locations, most commonly in the back, shoulder and face. We present a biopsy-proven case that arose as a result of heavy gym-related activities. In particular, a heavy barbell was rested on his vertebral prominence at the level of C7/T1 during leg squatting. Repetitive trauma as a cause for extra-nuchal-type fibromas has been sparsely reported, but we suggest that sustained high pressure is an additional required feature. Although this lesion was in the posterior neck, it was contained entirely within the subcutaneous tissues without involvement of the nuchal ligament. Hence, it was considered an extra-nuchal fibroma. A description of key ultrasound and MRI imaging characteristics are provided to assist in making the diagnosis, along with a review of the current literature and a discussion of differential diagnoses.

The Role of a Virtual Noncalcium Dual-Energy CT Application in the Detection of Bone Marrow Edema in Peripheral Osteomyelitis.

Purpose: To determine the sensitivity and specificity of dual-energy CT (DECT) virtual noncalcium images (VNCa) with bone and soft tissue reconstructions in the diagnosis of osteomyelitis. Materials & Methods: Between December 1, 2014 to December 1, 2020, 91 patients who had 99 DECT performed for a clinical indication of osteomyelitis with corresponding MRI, triphasic bone scan and/or white blood cell scintigraphy with CT/SPECT performed either 2 weeks before or 1 month after the DECT were retrospectively identified. The presence or absence of osteomyelitis was established using a second imaging test, bone biopsy or surgery. Two radiologists interpreted VNCa images alone and with bone and soft tissue reconstructions for osteomyelitis. Fleiss k statistics was used to assess inter-level agreement. Results: Osteomyelitis was present in 26 cases (26.2%), of which 4 cases (4%) had co-existing septic arthritis. DECT was performed at the following sites: ankle/foot (n = 59), calf (n = 12), knee (n = 3), thigh (n = 7), hip (n = 9), pelvis (n = 6), wrist/hand (n = 1), and shoulder (n = 2). Sensitivity with VNCa images alone was 53.8% and 73.1% and specificity was 84.9% and 71.2%. Sensitivity with VNCa images and bone and soft tissue reconstructions was 80.8% and 80.8% and specificity was 80.8% and 72.6%. Interobserver agreement was 76.7% (76 of 99 cases), for VNCa images alone (k = .487), and 66.7% (66 of 99 patients) for bone and soft tissue reconstructions with VNCa images together (k = .390). Conclusion: When VNCa images were combined with bone and soft tissue reconstructions, there is improved sensitivity in the diagnosis of osteomyelitis.

A Single-Center 10-Year Retrospective Analysis of Cryoablation for the Management of Desmoid Tumors.

PURPOSE: To determine the efficacy and safety of cryoablation in patients with desmoid tumors (DTs) retrospectively over a 10-year period at a single institution. MATERIALS AND METHODS: Between February 25, 2010, and February 25, 2020, 25 patients (age, 12-80 years) with 26 lesions (mean preprocedural tumor volume was 237 cm3) were treated over 44 cryoablation procedures. Eleven patients were treated with first-line therapy. Fourteen patients had previous medical therapy, radiotherapy, and/or surgery. Subsequent clinical follow-up, imaging outcomes, and safety were analyzed for technical success, change in total lesion volume (TLV) and viable tumor volume (VTV), modified response evaluation criteria in solid tumors (mRECIST), progression-free survival (PFS) for tumor progression and symptom recurrence, symptom improvement, and procedure-related complications. Symptomatic improvement was defined as documentation of relief of pain (partial or complete) and/or functional impairment. RESULTS: All procedures were technically successful. At 7-12 months, median changes in TLV and VTV were -6.7% (P = .809) and -43.7% (P = .01), respectively. At 10-12 months, the mRECIST responses were complete response, 0%; partial response, 61.5% (8/13); stable disease, 30.8% (4/13); and progressive disease, 7.7% (1/13). The median PFS for tumor progression and symptom recurrence were not reached, with a median follow-up of 15.3 and 21.0 months, respectively. Symptomatic relief (partial or complete) was achieved in 96.9% (32/33) of patients. One major complication was noted (2.4%). CONCLUSIONS: In this retrospectively identified cohort, cryoablation was effective and safe for the local control of extra-abdominal DTs in short-term follow-up.

Impact of 24/7/365 Attending Radiologist Coverage on the Turnaround Time in an Emergency and Trauma Radiology Department.

OBJECTIVE: To study the impact of 24/7/365 attending radiologist coverage on the turnaround time (TAT) of trauma and nontrauma cases in an emergency and trauma radiology department. PATIENTS AND METHODS: This was a retrospective chart review in which TAT of patients coming to the emergency department between 2 periods: (1) December 1, 2012, to September 30, 2013, and (2) January 1, 2017, to January 30, 2018, and whose reports were read by an attending emergency and trauma radiologist was noted. RESULTS: The 24/7/365 radiology coverage was associated with a significant reduction in TAT of computed tomography reports, and the time reduction was comparable between trauma and nontrauma cases. In adjusted models, the extension of radiology coverage was associated with an average of 7.83 hours reduction in overall TAT (95% confidence interval [CI]: 7.44-8.22) for reports related to trauma, in which 2.73 hours were due to reduction in completion to transcription time (TC; 95% CI: 2.53-2.93), and 5.10 hours were due to reduction in transcription to finalization time (TF; 95% CI: 4.75-5.44). For reports related to nontrauma cases, 24/7/365 coverage was associated with an average of 6.07 hours reduction in overall TAT (95% CI: 3.54-8.59), 2.91 hours reduction in TC (95% CI: 1.55-4.26), and 3.16 hours reduction in TF (95% CI: 0.90-5.42). CONCLUSION: Our pilot study demonstrates that the implementation of on-site 24/7/365 attending emergency radiology coverage at a tertiary care center was associated with a reduced TAT for trauma and nontrauma patients imaging studies. Although the magnitude and precision of estimates were slightly higher for trauma cases as compared to nontrauma cases. Trauma examinations stand to benefit the most from 24/7/365 attending level radiology coverage.

Impact of 24/7/365 Attending Radiologist Coverage on the Turnaround Time of Trauma-Related Imaging Studies Being Finalized Within 48 Hours in an Emergency Radiology Department, Offering a Perspective from a Tertiary Care Hospital.

OBJECTIVE: To offer an evidence-based account of the effect of 24/7/365 attending radiologist coverage on the turnaround time (TAT) of trauma-related radiographs finalized within 48 hours of exam completion, drawing data from an emergency radiology department of a tertiary care hospital in Vancouver, British Columbia. MATERIALS AND METHODS: This was a retrospective chart review, where TATs of imaging studies for a sample of trauma patients, who had visited the emergency department of the Vancouver General Hospital between two time periods, January 1 to September 30, 2013, and January 1 to September 30, 2017, were noted. RESULTS: In models adjusted for patient's age, sex, and seasonality, the 24/7/365 attending radiologist coverage was associated with an average of 19.1 (95% confidence interval [CI]: 18.7-19.4) hours of reduction in time from exam completion to report finalization by an attending radiologist. Approximately 11.3 (95% CI: 18.7-19.4) hours was due to reduction in time from exam completion to preliminary diagnosis of reports. When the impact of the increased number of radiology staff in 2017 was removed in the analysis, the overall TAT was reduced by 13.3 (95% CI: 13.0-13.6) hours and the time from exam completion to preliminary report was reduced by 7.8 (95% CI: 7.6-8.1) hours. LIMITATION: Since we have used a simple random sample (SRS) for this research, this study does not describe the burden of reports that are finalized in the emergency and trauma radiology department during the given time periods. CONCLUSION: Our pilot study demonstrates that the implementation of 24/7/365 attending radiology coverage significantly reduces TAT for finalized radiology reports of all modalities of trauma imaging studies in an emergency and trauma radiology department. POLICY IMPLICATION: This research serves the contemporary health-care administration, policymaking information needs by providing the evidence for significantly reduced TAT of finalized radiology reports from a Canadian perspective.

Top-Ten Tips for Dual-Energy CT in MSK Radiology.

Dual-energy computed tomography (DECT) has the potential to detect musculoskeletal pathology with greater sensitivity than conventional CT alone at no additional radiation dose to the patient. It therefore has the potential to reduce the need for further diagnostic imaging or procedures (e.g., joint aspirations in the case of gout or magnetic resonance imaging to confirm undisplaced fractures).DECT is a well-established technique for the detection of gout arthropathy. Multiple newer applications have shown clinical potential including bone marrow edema detection and metal artifact reduction. Collagen analysis, bone marrow lesion detection, and iodine mapping in CT arthrography are areas of possible future application and development.This article outlines 10 tips on the use of DECT imaging of the musculoskeletal system, explaining the technique and indications with practical suggestions to help guide the radiologist.

Detection of Bone Marrow Edema in Nondisplaced Hip Fractures: Utility of a Virtual Noncalcium Dual-Energy CT Application.

Purpose To quantify the sensitivity and specificity of dual-energy computed tomographic (CT) virtual noncalcium images in the detection of nondisplaced hip fractures and to assess whether obtaining these images as a complement to bone reconstructions alters sensitivity, specificity, or diagnostic confidence. Materials and Methods The clinical research ethics board approved chart review, and the requirement to obtain informed consent was waived. The authors retrospectively identified 118 patients who presented to a level 1 trauma center emergency department and who underwent dual-energy CT for suspicion of a nondisplaced traumatic hip fracture. Clinical follow-up was the standard of reference. Three radiologists interpreted virtual noncalcium images for traumatic bone marrow edema. Bone reconstructions for the same cases were interpreted alone and then with virtual noncalcium images. Diagnostic confidence was rated on a scale of 1 to 10. McNemar, Fleiss κ, and Wilcoxon signed-rank tests were used for statistical analysis. Results Twenty-two patients had nondisplaced hip fractures and 96 did not have hip fractures. Sensitivity with virtual noncalcium images was 77% and 91% (17 and 20 of 22 patients), and specificity was 92%-99% (89-95 of 96 patients). Sensitivity increased by 4%-5% over that with bone reconstruction images alone for two of the three readers when both bone reconstruction and virtual noncalcium images were used. Specificity remained unchanged (99% and 100%). Diagnostic confidence in the exclusion of fracture was improved with combined bone reconstruction and virtual noncalcium images (median score: 10, 9, and 10 for readers 1, 2, and 3, respectively) compared with bone reconstruction images alone (median score: 9, 8, and 9). Conclusion When used as a supplement to standard bone reconstructions, dual-energy CT virtual noncalcium images increased sensitivity for the detection of nondisplaced traumatic hip fractures and improved diagnostic confidence in the exclusion of these fractures. © RSNA, 2017 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on March 17, 2017.

Dual-Energy CT for the Musculoskeletal System.

The principal advantages of dual-energy computed tomography (CT) over conventional CT in the musculoskeletal setting relate to the additional information provided regarding tissue composition, artifact reduction, and image optimization. This article discusses the manifestations of these in clinical practice-urate and bone marrow edema detection, metal artifact reduction, and tendon analysis, with potential in arthrography, bone densitometry, and metastases surveillance. The basic principles of dual-energy CT physics and scanner design will also be discussed. © RSNA, 2016.

Getting the Most From Your Dual-Energy Scanner: Recognizing, Reducing, and Eliminating Artifacts.

OBJECTIVE: Dual-energy CT (DECT) is an innovative imaging modality that allows superior detection of pulmonary embolism, enhanced detection of urate in gout, and improved assessment of metal prostheses when compared with conventional CT. CONCLUSION: The primary aim of this review is to describe these DECT protocols and compare each to its respective diagnostic reference standards. Moreover, this review will describe how to recognize, reduce, and eliminate DECT artifacts, thereby maximizing its diagnostic capabilities.

Artifacts in dual-energy CT gout protocol: a review of 50 suspected cases with an artifact identification guide.

OBJECTIVE: The objective of our study was to discover the types and incidence of artifacts in dual-energy CT (DECT) using datasets of 50 consecutive patients who underwent a four-limb DECT protocol for the evaluation of suspected gout. Identification of artifacts and techniques for artifact reduction are discussed. CONCLUSION: Artifacts commonly occur in DECT performed for gout assessment but are usually readily recognizable. For 90% of the patients in our study who underwent imaging for suspected gout, DECT showed some type of artifact, with nail bed and skin artifacts being the most common.

CT-guided percutaneous cryoablation for osteoid osteoma: initial experience in adults.

OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of CT-guided percutaneous cryoablation for the treatment of osteoid osteoma in adults. MATERIALS AND METHODS: A retrospective case series over a 30-month period involved 10 consecutive adult patients (nine male and one female patients; mean age, 27.9 years; age range, 16-49 years) who underwent CT-guided percutaneous cryoablation for management of osteoid osteoma. Clinical and technical success was evaluated with postprocedure MRI at 4-5 weeks and with digital numeric pain scores taken before and immediately after the procedure, as well as at primary follow-up (4-10 weeks; average, 5 weeks) and secondary follow-up (23-29 weeks; average, 24 weeks). RESULTS: Clinical and technical success rates were 100%. Average digital numeric pain scores were 7.4 before the procedure, 1.5 after procedure, 0.5 at the primary follow-up, and 0.3 at secondary follow-up. No minor or major complications were noted during the procedure, recovery period, primary follow-up, or secondary follow-up. CONCLUSION: CT-guided percutaneous cryoablation is safe and effective in the treatment of osteoid osteoma in adults.

Dual-energy computed tomographic tendon algorithm in acute trauma: initial experiences.

Computed tomography has become increasingly popular in the assessment of limbs in the acute trauma setting. Bony anatomic detail is excellent; however, soft tissue detail is typically limited, especially when compared with ultrasound and magnetic resonance imaging. The advent of dual-energy computed tomography has allowed additional information to be gathered regarding the morphology of collagen-based soft tissue structures. We report our initial experiences of 4 cases with imaging and clinical correlation.

Dual-energy computed tomographic virtual noncalcium algorithm for detection of bone marrow edema in acute fractures: early experiences.

Computed tomography (CT) is often used to assess the presence of occult fractures when plain radiographs are equivocal in the acute traumatic setting. While providing increased spatial resolution, conventional computed tomography is limited in the assessment of bone marrow edema, a finding that is readily detectable on magnetic resonance imaging (MRI).Dual-energy CT has recently been shown to demonstrate patterns of bone marrow edema similar to corresponding MRI studies. Dual-energy CT may therefore provide a convenient modality for further characterizing acute bony injury when MRI is not readily available. We report our initial experiences of 4 cases with imaging and clinical correlation.

The distribution of urate deposition within the extremities in gout: a review of 148 dual-energy CT cases.

OBJECTIVE: Clinical detection of gout can be difficult due to co-existent and mimicking arthropathies and asymptomatic disease. Understanding of the distribution of urate within the body can aid clinical diagnosis and further understanding of the resulting pathology. Our aim was to determine this distribution of urate within the extremities in patients with gout. MATERIALS AND METHODS: All patients who underwent a four-limb dual-energy computed tomography (DECT) scan for suspected gout over a 2-year period were identified (n = 148, 121 male, 27 female, age range, 16-92 years, mean = 61.3 years, median = 63 years). The reports of the positive cases were retrospectively analyzed and the locations of all urate deposition recorded and classified by anatomical location. RESULTS: A total of 241 cases met the inclusion criteria, of which 148 cases were positive. Of these, 101 (68.2 %) patients had gout in the foot, 81 (56.1 %) in the knee, 79 (53.4 %) in the ankle, 41 (27.7 %) in the elbow, 25 (16.9 %) in the hand, and 25 (16.9 %) in the wrist. The distribution was further subcategorized for each body part into specific bone and soft tissue structures. CONCLUSIONS: In this observational study, we provide for the first time a detailed analysis of extremity urate distribution in gout, which both supports and augments to the current understanding based on clinical and microscopic findings.