CT-guided lumbar facet cyst rupture and corticosteroid injection: technique, approach, and procedural and clinical success rates.

PURPOSE: To evaluate success rates of computed tomography (CT)-guided lumbar facet synovial cyst (LFC) rupture. MATERIALS AND METHODS: We retrospectively reviewed all LFC ruptures performed by a single musculoskeletal radiologist with > 10 years of experience, using posterior facet approach and/or direct puncture by ipsilateral/contralateral interlaminar, or transforaminal approach. All patients also received a corticosteroid injection. Rupture rates were calculated, and clinical success rate was determined through medical record review. Pre-procedure magnetic resonance imaging (MRI) images and CT procedure images were also reviewed for LFC and facet joint imaging features that may predict rupture. RESULTS: There were 37 patients, 17 (46%) female and 20 (54%) male, ages 62 ± 12 (range 39-87) years. Thirty-four (92%) of LFC were successfully ruptured, 17 (50%) by facet approach and 17 (50%) by direct cyst puncture. At least one direct puncture approach was possible in 35 (95%) patients. No MRI or CT LFC or facet joint features predicted cyst rupture. Thirty-one (91%) of patients reported immediate pain relief, and 19 (53%) did not have further intervention for LFC-related pain. Sixteen (84%) of these patients remained pain-free for an average follow-up time period of 28 months. Fourteen (39%) of patients required surgical intervention. There were no complications. CONCLUSION: Our systematic approach to CT-guided LFC rupture is safe and has high technical and clinical success rates similar to prior studies. Since there are no definitive imaging features that determine rupture success, this procedure can almost always be attempted as a first-line treatment for LFC.

Whole body imaging in musculoskeletal oncology: when, why, and how.

The use of whole-body imaging has become increasingly popular in oncology due to the possibility of evaluating total tumor burden with a single imaging study. This is particularly helpful in cases of widespread disease where dedicated regional imaging would make the evaluation more expensive, time consuming, and prone to more risks. Different techniques can be used, including whole-body MRI, whole-body CT, and PET-CT. Common indications include surveillance of cancer predisposing syndromes, evaluation of osseous metastases and clonal plasma cell disorders such as multiple myeloma, and evaluation of soft tissue lesions, including peripheral nerve sheath tumors. This review focuses on advanced whole-body imaging techniques and their main uses in musculoskeletal oncology.

Relationship of Imaging-guided Corticosteroid Injections to COVID-19 Incidence in the Pandemic Recovery Period.

Background Corticosteroids injected for the treatment of musculoskeletal pain are systemically absorbed and can affect the immune response to viral infections. Purpose To determine the incidence of symptomatic COVID-19 disease in individuals receiving image-guided corticosteroid injections for musculoskeletal pain compared with the general population during the pandemic recovery period. Materials and Methods In this prospective cohort multicenter study, adults with a history of musculoskeletal pain who underwent imaging-guided intra-articular and spine corticosteroid injections from April 2020 to February 2021 were consecutively enrolled. Participants were followed for a minimum of 28 days through their electronic medical record (EMR) or by direct phone communication to screen for COVID-19 test results or symptoms. Clinical data, including body mass index (BMI), were also obtained from the EMR. The incidence of COVID-19 in the state was obtained using the Massachusetts COVID-19 Response Reporting website. The Student t test was used for continuous variable comparisons. Univariable analyses were performed using the Fisher exact test. Results A total of 2714 corticosteroid injections were performed in 2190 adult participants (mean age, 59 years ± 15 [SD]; 1031 women). Follow-up was available for 1960 participants (89%) who received 2484 injections. Follow-up occurred a mean of 97 days ± 33 (range, 28-141 days) after the injection. Of the 1960 participants, 10 had COVID-19 within 28 days from the injection (0.5% [95% CI: 0.24, 0.94]) and 43 had COVID-19 up to 4 months after the injection (2.2% [95% CI: 1.6, 2.9]). These incidence rates were lower than that of the population of Massachusetts during the same period (519 195 of 6 892 503 [7.5%], P < .001 for both 28 days and 4 months). Participants diagnosed with COVID-19 (n = 10) within 28 days from the injection had a higher BMI than the entire cohort (n = 1960) (mean, 32 kg/m2 ± 10 vs 28 kg/m2 ± 6; P = .04). Conclusion Adults who received image-guided corticosteroid injections for pain management during the pandemic recovery period had a lower incidence of symptomatic COVID-19 compared with the general population. © RSNA, 2022 Online supplemental material is available for this article.

MR Imaging of the Knee Bursae and Bursal Pathology.

The main function of the knee bursae is to provide cushioning for the many periarticular ligaments, tendons, and osseous structures. Bursae can only be visualized when distended by fluid, therefore bursal anatomy is best evaluated by MR imaging using fluid-sensitive sequences. Knowledge of the normal bursal distribution is important to avoid incorrectly interpreting a distended bursa as a periarticular fluid collection or cyst. Bursal pathology usually results from trauma, chronic overuse, or inflammation, and may be associated with an underlying intra-articular process, given the presence of synovial lining and different degrees of communication with the joint.

Distal Triceps Tendon Tears: Magnetic Resonance Imaging Patterns Using a Systematic Classification.

OBJECTIVE: This study aimed to evaluate distal triceps tendon tear patterns using a systematic classification based on the tendon's layered structure. METHODS: We retrospectively identified Magnetic resonance imaging (MRI) examinations with triceps tendon tears that underwent reconstructive surgery. Magnetic resonance images were reviewed independently by 2 musculoskeletal radiologists to determine tendon layer involvement and ancillary findings, including tear size, involvement of triceps lateral expansion, and presence of olecranon bursal fluid. Surgical reports were scrutinized for level of anatomic detail and correlation with imaging findings. RESULTS: We identified 69 triceps tendon tears in 68 subjects (61 men, 7 women; mean age, 45 ± 12 years) who underwent surgical reconstruction. On MRI, the superficial layer was always involved with either a partial or full-thickness tear. The most common tear pattern was a combination of superficial layer full-thickness tear with deep layer partial tear (25 of 69 [36%]). Mean tear length was 24 ± 12 mm. We found no cases of isolated deep layer tears. Involvement of triceps lateral expansion and presence of bursal fluid correlated positively with tear severity of superficial and deep layers (P < 0.001). Detailed surgical correlation was limited, with only 9 of 69 (13%) of surgical reports containing information specifically addressing individual tendon layers. CONCLUSIONS: Triceps tendon tears show tear patterns following its layered structure and can be assessed by MRI. Radiologists and surgeons are encouraged to describe tear patterns considering both superficial and deep tendon layers.

Role of FDG PET in the staging of multiple myeloma.

18F-Fluorodeoxyglucose (FDG) PET has been used for staging of hematologic malignancies for years. In multiple myeloma, this imaging modality can be used in many different scenarios, including initial staging, evaluation of treatment response, and investigation of residual disease or early relapse. FDG PET-CT has excellent diagnostic performance, similar to other advanced imaging modalities such as whole-body CT and MRI, and it is particularly helpful for the assessment of extramedullary disease. It also offers important prognostic information on survival and risk of relapse, both at baseline and after therapy. This review will cover the main applications, advantages, and limitations of FDG PET-CT in multiple myeloma and related clonal plasma cell proliferative disorders, such as smoldering multiple myeloma and plasmacytoma.

Kinematic MRI of ischiofemoral impingement.

OBJECTIVE: To examine the effect of external hip rotation on ischiofemoral (IF) and quadratus femoris (QF) spaces using real-time kinematic MRI, with the hypothesis that hips with IF and QF space narrowing have distinct motion patterns compared with control hips. MATERIALS AND METHODS: This prospective study was IRB-approved and complied with HIPAA guidelines. We recruited women (≥ 18 years) with and without ischiofemoral impingement to undergo kinematic MRI of the hips. A kinematic imaging protocol using T2-HASTE was performed beginning at maximal internal rotation followed by active external hip rotation. The duration of each acquisition was 30 s, providing 8 images/3 s. IF and QF spaces, and femoral metaphyseal and lesser trochanter centroid coordinates were measured on sequential images. Hips were classified as controls or narrowed based on IF and QF space thresholds and compared statistically throughout motion stages. RESULTS: The cohort comprised 12 women (24 hips; 10 control and 14 narrowed hips) aged 58 ± 10 years. External rotation caused IF space reduction of 59% in narrowed hips versus 41% in control hips. QF space decreased 71% in narrowed hips versus 50% in control hips. IF and QF spaces differed significantly between groups only when external rotation exceeded the neutral position (P < 0.02 for both). The lesser trochanter terminated more posteriorly in narrowed hips compared with controls (P = 0.03). CONCLUSIONS: Kinematic MRI during external hip rotation in women with narrowed and control hips reveals dynamic differences in IF and QF spaces and lesser trochanter terminal position.

Novel Associations Between Genome-Wide Single Nucleotide Polymorphisms and MR Enterography Features in Crohn's Disease Patients.

BACKGROUND: Patient genetic polymorphism is associated with Crohn's clinical behavior; however, its association with magnetic resonance enterography (MRE) imaging appearance is not known. PURPOSE: To analyze a set of known Crohn's disease (CD)-related single nucleotide polymorphisms for associations with MRE imaging phenotype and frequency of imaging. STUDY TYPE: Retrospective. POPULATION: 54 patients (mean age 40 years; 32 females and 22 males) with established CD from 2009 to 2016 who underwent baseline MRE and genetic testing for the presence of 168 single nucleotide polymorphisms (SNPs) potentially associated with inflammatory bowel disease. FIELD STRENGTH/SEQUENCE: 1.5T or 3T clinical scanners, standard MRE clinical pulse sequences, including T2 -weighted single-shot fast spin echo, balanced steady-state free precession, T2 -weighted fast spin echo fat-suppressed, and T1 -weighted fat-suppressed pre- and postcontrast imaging. ASSESSMENT: Three readers (all body imaging fellowship-trained radiologists) independently evaluated all imaging for the presence or absence of active disease and penetrating complications. Date of onset and frequency of endoscopies and cross-sectional imaging (CSI) were recorded. Disease behavior and distribution were categorized according to the Vienna and Montreal classifications, respectively. STATISTICAL TESTS: Student's t-test and Fisher's exact test were used to assess significance of continuous and categorical variables, respectively. A hidden Markov model statistical knockoff approach was also applied for the analysis of genetic-imaging associations, with corrected P < 0.05 considered significant. RESULTS: MRE demonstrated active bowel inflammation in 42 (78%) patients, strictures in 13 (28%), and fistulae in 13 (28%). The SNP rs1292053 (RBS6KB1) was highly associated with small bowel inflammation and luminal narrowing, with observed frequencies of association 0.66 and 0.39, respectively (P = 0.001). rs6062504 (Decoy receptor 3) was associated with lower age of onset (P = 0.012), higher proportion of early disease onset patients (P = 0.012), and higher average number of CSI/year (P = 0.014). DATA CONCLUSION: This study demonstrated significant associations between CD genotype and MRE phenotype and frequency of cross-sectional imaging. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Are patients more likely to have hip osteoarthritis progression and femoral head collapse after hip steroid/anesthetic injections? A retrospective observational study.

OBJECTIVE: To evaluate progression of osteoarthritis and femoral head articular surface collapse in hip steroid/anesthetic injection patients (HIPs). MATERIALS AND METHODS: This study was IRB-approved and HIPAA-compliant. Two musculoskeletal radiologists performed retrospective, blinded reviews of radiography for 70 HIPs (40 mg triamcinolone/4 mL 0.5% preservative-free ropivacaine) with a 3- to 10-month follow-up and two control groups: demographic-matched patients with similar hip radiograph follow-up duration but no injection; and glenohumeral joint injection patients. Discordant evaluations were adjudicated by a third, senior reader. Groups were compared using Fisher's exact and unpaired t tests. RESULTS: There were 70 HIPs (mean age 67 ± 17 (range 19-92) years; 44 women, 26 men), who were followed for a mean of 6 ± 2 (3-12) months. Thirty-one (31 out of 70, 44%) of HIPs had progression of osteoarthritis after injection, versus 17 out of 70 (24%) of hip controls (HCs) and 13 out of 44 (30%) of glenohumeral injection patients (GIPs). This difference between HIPs and HCs was statistically significant (p = 0.02) but not that between HIPs and GIPs (0.17). Twelve (12 out of 70, 17%) HIPs had new collapse, compared with 1 out of 70 (1%) of HCs and 1 out of 44 (2%) of GIPs. This difference was statistically significant (HCs: p = 0.002; GIPs: p = 0.02). CONCLUSION: Hip steroid/anesthetic injection patients are more likely to demonstrate osteoarthritis progression and femoral head collapse than HC and GIPs in the injected joint 3-12 months after steroid and anesthetic injection. Further evaluation of hip injectates and the injection population is warranted.

Peroneal Tendon Tears: We Should Consider Looking at the Muscle Instead.

INTRODUCTION: The purpose of this study was to determine whether tears of the peroneus brevis (PB) tendon correlate with increased fatty infiltration of the PB muscle on MRI compared with musculature without clinical evidence of peroneal pathology. METHODS: Ankle MRI scans of patients with PB tendon tearing (tear group) were compared with those of patients without clinical evidence of peroneal pathology (control group). Two reviewers graded the PB muscle belly according to the Goutallier classification. RESULTS: Thirty patients were included in each group. The mean Goutallier scores for the tear and control groups were 0.52 (±0.72) and 0.05 (±0.15), respectively (P = 0.0019). The level of interobserver agreement between reviewers was moderate (intraclass correlation coefficient = 0.75; 95% confidence interval, 0.57 to 0.85). DISCUSSION: Patients with PB tendon tear demonstrate markedly higher grades of fatty degeneration compared with patients without peroneal pathology. The Goutallier classification may become a valuable instrument for assessing the severity of a PB tear. LEVEL OF EVIDENCE: Level III-diagnostic study.

Hallux saltans due to stenosing tenosynovitis of flexor hallucis longus: dynamic sonography and arthroscopic findings.

Triggering of the toes is rare, with isolated cases reported in the literature involving predominantly the flexor hallucis longus (FHL) tendon, a condition known as "hallux saltans" (HS). We report the dynamic sonographic findings of a 42-year-old female with a 2-month history of ankle pain and triggering of right hallux, consistent with HS. Sonography demonstrated tenosynovitis and focal thickening of FHL at the level of hindfoot, with a fibrous band adjacent to the tendon. Dynamic ultrasound showed triggering and snapping of FHL tendon during hallux flexion and extension, respectively. We present comprehensive documentation of this rare entity, including sonographic still images and cine clips, as well as correlation with arthroscopic surgical findings.

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.