The effect of gadolinium-based intravenous contrast in the initial characterization of musculoskeletal soft tissue tumors.

OBJECTIVE: To determine if gadolinium-based contrast agents increase the sensitivity, specificity or reader confidence of malignant potential in musculoskeletal soft tissue tumors. METHODS: Pre- and post-contrast MRI studies from 87 patients were read by three independent radiologists of different experience. Readers noted malignant potential and confidence in their diagnosis based on pre-contrast and post-contrast MRI studies. Statistical models assessed for agreement between MRI reader diagnosis and pathologic results as well as analyzing effects of contrast on reader confidence. Inter- and intra-observer variabilities of malignant potential were also calculated. RESULTS: 87 patients (48 benign and 39 malignant; mean [± SD] age 51 ± 17.9 and 57.1 ± 17.1, respectively) were evaluated. For all readers, pre-contrast and post-contrast sensitivities were 68.1 % and 70.6 % while pre-contrast and post-contrast specificities were 84.6 % and 83.8 %, respectively without significant change (p=0.88). There was not a significant association with the use of contrast and prediction of malignant potential with or without the resident reader (p=0.65 and p=0.82). Use of contrast was significantly associated with higher levels of reader confidence (p=0.02) for all readers. Inter- and intra-observer variabilities were in good agreement (W = 0.77 and 0.70). CONCLUSION: The addition of a post-contrast sequence increased reader confidence in their diagnosis without a corresponding significant increase in accurate prediction of malignant potential.

Asymptomatic Intracardiac Cement Embolism Following Kyphoplasty.

Cement extravasation can occur during vertebral body augmentation such as kyphoplasty and vertebroplasty with diverse presentation and resultant treatment. The cement can embolize through venous vasculature to the thorax where it poses a potential threat to the cardiovascular and pulmonary systems. A thorough risk-benefit analysis should be conducted to select the appropriate treatment course. We present an asymptomatic case of cement extravasation to the heart and lungs during kyphoplasty.

The effect of virtual interviews on the musculoskeletal radiology fellowship match.

OBJECTIVE: Resulting from the COVID-19 pandemic, a virtual interview format was adopted in lieu of in-person interviews for fellowship recruitment. The purpose of this study is to analyze the potential effect that virtual interviews have on musculoskeletal radiology fellowship match results and collect opinions of the process. MATERIALS AND METHODS: An anonymous survey was sent to 87 listed US-based musculoskeletal radiology fellowship directors, who were asked for their 2019-2020 and 2020-2021 match data: fellowship positions, interviewees, ranked interviewees, and matched ranks. They rated effectiveness of virtual interviews on a ten-point scale (1 poor-10 excellent) and provided an ideal percentage of future interviews to be conducted virtually. RESULTS: Thirty responses were received (34.4% response rate). Primary analysis found significant increase in the mean number of candidates ranked in 2020-2021, 14.6 to 17.5 (p = 0.047). The mean rank of matched applicants increased from 6.02 to 6.43, without significance (p = 0.821). Secondary analysis, which attempted to exclude internally matched programs, found significant increases in 2020-2021 in the mean number of applicants-28.7 to 32.4 (p = 0.017), interviews conducted-17.8 to 21.3 (p = 0.007), and candidates ranked by programs-16.3 to 19.8 (p = 0.015). The mean rank of matched applicants increased from 6.39 to 7.03, without significance (p = 0.713). CONCLUSION: With results showing an increase in applications, interviews conducted, and ranked applicants while lowering the average rank of matched candidates, musculoskeletal radiology fellowship directors should consider interviewing more applicants than they usually would in the prior in-person recruitment format.

Intra-articular Osteoid Osteoma of the Olecranon Fossa.

Osteoid osteomas are benign primary bone lesions characterized by a central nidus with surrounding reactive sclerosis, classically presenting as worsening nocturnal pain relieved by non-steroidal anti-inflammatory medications (NSAIDs). These most commonly occur in intracortical bone and the diaphysis of long bones. As a rare entity, intra-articular osteoid osteomas present unusually, often resulting in a delayed or incorrect diagnosis. We present a case of an intra-articular osteoid osteoma, emphasizing the importance of MRI in aiding diagnosis in this atypical location.

MR Imaging of Knee Cartilage Injury and Repair Surgeries.

Cartilage injuries are common and may predispose to early accelerated osteoarthritis. Magnetic resonance (MR) imaging is critical in the detection and characterization of acute and chronic cartilage injuries. Several surgical approaches including microfracture, osteochondral allografting, autologous osteochondral transfer system, and autologous chondrocyte implantation have been developed to treat cartilage lesions. The goals of these treatments include relief of symptoms, restoration of joint function, and delay of progression of osteoarthritis. Imaging evaluation by MR imaging plays a crucial role in diagnosis and surgical planning as well as monitoring for postoperative complications.

The Everted Acetabular Labrum: Patho-anatomy, Magnetic Resonance Imaging and Arthroscopic Findings of a Native Variant.

PURPOSE: The purpose of this study was to introduce a native labral variant, the everted acetabular labrum, and to describe the patho-anatomy, magnetic resonance imaging and magnetic resonance arthrogram (MRI/MRA) characteristics and the arthroscopic findings in this condition. METHODS: All primary hip arthroscopy procedures performed by the senior author between June 2013 and January 2020 were reviewed retrospectively. An everted acetabular labrum was identified as a segment of labrum that lacked apposition to the femoral head with the hip off traction. All everted labra were treated with labral advancement and repair with or without augmentation or reconstruction. The labrum-to-femoral head distance was measured in 3T MRI/MRA at the 1-2 o'clock position. A random selection of 38 hips without an everted labrum served as controls to compare radiographic parameters. RESULTS: A total of 68 hips were identified as having an everted labrum during the study period (mean age, 29.1 years), and 55 hips had advanced imaging available for review. MRI/MRA scans revealed the everted labrum to have a triangular shape in 17 hips (31%) and a blunted/round shape in 38 hips (69%), which differed significantly from controls (triangular 25/38 [66%], blunted 13/38 [34%], P < 0.001). The average labrum-to-femoral head distance was 1.4 mm for everted labra versus 0.0 mm for controls (P < 0.0001) and the mean labral lengths and widths were significantly shorter than those of controls (both P < 0.01). Of the hips, 8 underwent labral reconstruction or augmentation, and 61 underwent labral advancement/repair. CONCLUSION: The everted acetabular labrum is a native variant that is identifiable during hip arthroscopy by assessing the labral seal off traction. Preoperative MRI/MRA findings can be highly predictive of an everted labrum. Surgical treatment includes labral advancement and repair or reconstruction to restore contact between the labrum and the femoral head. LEVEL OF EVIDENCE: III, retrospective comparative study.

Spinal Injections.

Spinal pain is a common complaint and cause of disability in the United States, affecting most individuals at some point in their lives. The complex anatomy of the spine leads to multiple potential and coexisting etiologies for pain, and the differentiation of these sources can present a diagnostic challenge. Image-guided spinal injections can provide both diagnostic information identifying pain location as well as prolonged therapeutic relief as an alternative to medical management. Anesthetic and corticosteroid medications can be administered within the epidural space through transforaminal or interlaminar approaches, blocking various sensory nerves, or directly within the facet joints. Proceduralists must be aware of associated patient considerations, techniques, and potential complications to perform the procedures safely. We discuss image-guided spinal injection techniques, based on best practices and our experiences.

Minding the Gap in Vertebroplasty: Vertebral Body Fracture Clefts and Cement Nonunion.

BACKGROUND: Vertebroplasty and kyphoplasty are leading treatments for patients with vertebral body compression fractures. Although cement augmentation has been shown to help relieve pain and instability from fractures containing a cleft, there is some controversy in the literature regarding the procedure's efficacy in these cases. Additionally, some of the literature blurs the distinction between clefts and cement patterns (including cement nonunion and cement fill pattern). Both clefts and cement patterns have been mentioned in the literature as risks for poorer outcomes following cement augmentation, which can result in complications such as cement migration. OBJECTIVES: This study aims to identify the prevalence of fracture clefts and cement nonunion, the relationship between them as well as to cement fill pattern, and their association with demographics and other variables related to technique and outcomes. STUDY DESIGN: Retrospective cohort study. SETTING: Interventional radiology department at a single site university hospital. METHODS: This retrospective cohort study assessed 295 vertebroplasties/kyphoplasties performed at the University of Colorado Hospital from 2008 to 2018. Vertebral fracture cleft and cement nonunion were the main variables of interest. Presence and characterization of a fracture cleft was determined on pre-procedural imaging, defined as an air or fluid filled cavity within the fractured vertebral body on magnetic resonance or computed tomography. Cement nonunion was evaluated on post-procedural imaging, defined as air or fluid surrounding the cement bolus on magnetic resonance or computed tomography or imaging evidence of cement migration. Cement fill pattern was assessed on procedural and/or post-procedural imaging. Pain improvement scores were based on a visual analog score immediately prior to the procedure and during clinical visits in the short-term follow-up period. Additional patient demographics, medical history, and procedure details were obtained from electronic medical chart review. RESULTS: Pre-procedural vertebral fracture clefts were demonstrated in 29.8% of our cases. Increasing age, secondary osteoporosis, and thoracolumbar junction location were associated with increased odds of clefts. There was no significant difference in pain improvement outcomes in patients following cement augmentation between clefted and non-clefted compression fractures. Clefts, especially large clefts, and cleft-only fill pattern were associated with increased odds of cement nonunion. Procedure techniques (vertebroplasty, curette, and balloon kyphoplasty) demonstrated similar proportion of cement nonunion and distribution of cement fill pattern. LIMITATIONS: Cement nonunion was observed in only 6.8% of cases. Due to this low proportion, statistical inference tends to have low power. Multiple levels were treated in nearly half of the study's patients undergoing a single vertebroplasty/kyphoplasty session; in these cases, each level was treated as independent rather than spatially correlated within the same study patient. CONCLUSIONS: Vertebral body fracture clefts are not uncommon and are related to (but distinct from) cement nonunion and cement fill patterns. Our study shows that, although patients with clefts will benefit from cement augmentation just as much as patients without a cleft, the performing provider should take note of cement fill and take extra steps to ensure optimal cement fill. These providers should also identify cement nonunion and associated complications (such as cement migration) on follow-up imaging.