Search

Objectives: To retrospectively evaluate the correlation between intradiscal gas and infection in patients percutaneously biopsied for suspected discitis-osteomyelitis., Materials and Methods: We retrospectively reviewed all CT-guided discitis-osteomyelitis biopsies performed between 2002 and 2022. Two independent trained musculoskeletal radiologists evaluated for presence of gas on CT and/or MRI within 1 week of the biopsy. Disagreements were resolved by a third musculoskeletal radiologist. CT was considered the gold standard for the detection of intradiscal gas. Pathology, microbiology, and imaging and clinical follow-up were used as the gold standard for presence of infection. Interrater agreement on CT and MRI, sensitivity, and positive predictive value were calculated, using the presence of gas as an indicator (test positive) for "no infection.", Results: There were 284 biopsies in 275 subjects (mean age 58 ± 1.0 (range 4-99) years; 101 (37%) females and 174 (63%) males). Of the biopsies, 12 (4%) were cervical, 80 (28%) were thoracic, 192 (68%) were lumbar, and 200 (70%) were considered true discitis-osteomyelitis based on pathology, imaging, and clinical follow-up. Interrater agreement was excellent for CT (kappa = 0.83) and poor for MRI (kappa =  - 0.021). The presence of gas had a 94% specificity and 76% negative predictive value for the absence of infection., Conclusion: CT is the preferred method for detecting intradiscal gas. The presence of gas means that discitis-osteomyelitis is unlikely. If intradiscal gas is present in the setting of discitis-osteomyelitis, the gas bubbles tend to be smaller and fewer in number., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: To evaluate clinical and radiological features of extraskeletal myxoid chondrosarcomas (EMC)., Material and Methods: Our pathology database was queried for cases of EMCs. Tumor location, size, imaging appearance, presence of metastases, disease recurrence, and clinical outcome were documented. Imaging studies were evaluated in consensus by a musculoskeletal radiologist and an orthopedic oncologist., Results: Thirty subjects met the inclusion criteria (mean age 52.7 ± 16.2 years; 19 male, 11 female), 17 (56.7%) of which had pre-operative imaging. Tumors occurred most often in the lower extremities (20/30; 66.7%). All cases presented as a soft-tissue mass without mineralization on XR or CT. On MRI, tumors were typically hyperintense on T2-weighted sequences (14/14; 100%) and had a chondroid matrix appearance (12/14; 85.7%). Tumor invasion was observed in 11 out of 16 (68.9%) patients and necrosis in 2 out of 11 subjects (18.2%). All subjects had their tumors examined by pathology, and 20 (66.7%) subjects also had descriptive information in addition to the diagnosis (tumor invasion, mitotic rate, and necrosis) noted in the pathology reports. The mean duration of follow-up was 9.4 ± 7.5 (1.0 - 29.6) years. At the last follow-up, 14 out of 28 (50%) subjects were disease-free, 6 out of 28 had persistent metastatic disease and 8 out of 28 had died., Conclusions: EMC is a rare sarcoma that commonly presents as lower extremity soft tissue mass with chondroid appearance on MRI. Unlike conventional chondrosarcomas, EMC do not demonstrate mineralization on XR or CT., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: To compare the frequency of elongated morphology of osteoid osteoma (OO) in children compared to adolescents and to determine if this elongated morphology is associated with radiofrequency ablation treatment failure., Materials and Methods: Retrospective review of first-time CT-guided radiofrequency ablation performed for presumed OO in patients < 21 years old between 1990 and 2023. Children were considered 0 to 10 years old, and adolescents were considered 11 to 20 years old. Treatment failure was considered symptomatic recurrence requiring follow-up intervention. The largest tumor dimensions in three orthogonal planes were measured using multiplanar reformatted technology. Maximum tumor dimension, tumor volume, and eccentricity index were calculated. Elongated morphology criteria were (a) largest dimension > 10 mm and (b) eccentricity index ≥ 3. Lesion locations were recorded. Statistical analyses included the chi-square test, Fisher's exact test, nonparametric Wilcoxon rank-sum test, receiver operating characteristic analysis, and Spearman's nonparametric rank correlation., Results: Of 366 included patients (median 15 years, IQR 11-18 years, 254 male), there were 86 (23.5%) children, 280 (76.5%) adolescents, and 24 (6.6%) cases of treatment failure. Elongated morphology was more common in children (19.7%) than adolescents (8.6%) (p = 0.004) and associated with younger age (p = 0.009). Elongated morphology was associated with treatment failure in children (p = 0.045) but not adolescents (p > .99) or all patients (p = 0.17). Treatment failure was not associated with age, largest dimension, eccentricity index, volume, or location., Conclusion: Elongated morphology of OO is associated with younger age and radiofrequency ablation treatment failure in children. Identifying this morphology may assist with counseling and treatment planning., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Background: Phosphaturic mesenchymal tumor (PMT) is a rare tumor that causes tumor-induced osteomalacia. Patients present with non-specific symptoms secondary to renal phosphate wasting and decreased bone mineralization. We sought to assess: (1) What are the common presenting features, laboratory and imaging findings, histologic findings of phosphaturic mesenchymal tumors? (2) What are the available treatment strategies for phosphaturic mesenchymal tumors and their long-term outcomes in terms of local recurrence and symptom control after treatment?, Methods: We retrospectively identified patients with a histologic diagnosis of PMT located in the axial or appendicular skeleton, or surrounding soft tissues. A total of 10 patients were finally included in our study., Results: Median tumor size was 1.9 cm (range, 1.1 to 6.1) and median time from symptom onset to diagnosis was 3 years (range, 0.5 to 15 years). All patients but one presented with hypophosphatemia (median 1.9 mg/dL, range 1.2 to 3.2). Pre-operative FGF-23 was elevated in all cases (median 423.5 RU/mL, range 235 to 8950). Six patients underwent surgical resection, three were treated percutaneously (radiofrequency ablation or cryoablation), and one refused treatment. Only one patient developed local recurrence and no patients developed metastatic disease. At last follow-up, nine patients showed no evidence of disease and one was alive with disease., Conclusion: Phosphaturic mesenchymal tumor is a rare tumor presenting with non-specific symptoms. Surgery is the standard treatment when negative margins can be achieved without significant morbidity. In patients with small tumors in surgically-inaccessible areas, radiofrequency ablation or cryoablation can be performed successfully., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Purpose: To report osteoporosis screening utilization rates among Asian American (AsA) populations in the USA., Methods: We retrospectively assessed the use of dual-energy X-ray absorptiometry (DXA) screening using the Medicare 5% Research Identifiable Files. Using Current Procedural Terminology (CPT) codes indicative of a DXA scan, we identified patients recommended for DXA screening according to the ACR-SPR-SSR Practice Parameters (females ≥ 65 years, males ≥ 70 years). Sociodemographic factors and their association with screening were evaluated using chi-square tests., Results: There were 80,439 eligible AsA beneficiaries, and 12,102 (15.1%) received osteoporosis screening. DXA rate for women was approximately four times greater than the rate for men (19.8% vs. 5.0%; p < 0.001). AsA beneficiaries in zip codes with higher mean household income (MHI) were more likely to have DXA than those in lower MHI areas (17.6% vs. 14.3%, p < 0.001). AsA beneficiaries aged < 80 were more likely to receive DXA (15.5%) than those aged ≥ 80 (14.1%, p < 0.001). There were 2,979,801 eligible non-AsA beneficiaries, and 496,957 (16.7%) received osteoporosis screening during the study period. Non-Hispanic white beneficiaries had the highest overall screening rate (17.5%), followed by North American Native (13.0%), Black (11.8%), and Hispanic (11.1%) beneficiaries. Comparing AsA to non-AsA populations, there were significantly lower DXA rates among AsA beneficiaries when controlling for years of Medicare eligibility, patient age, sex, location, and mean income (p < 0.001)., Conclusion: We found lower than expected DXA screening rates for AsA patients. A better understanding of the barriers and facilitators to AsA osteoporosis screening is needed to improve patient care., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

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., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: To better understand the current state of musculoskeletal fellowship program directors and identify opportunities for formal training that could increase job satisfaction, provide a broader knowledge base for mentoring/advising trainees and increase diversity in musculoskeletal radiology., Materials and Methods: Eighty-one fellowship program directors who signed the Fellowship Match Memorandum of Understanding with the Society of Skeletal Radiology were sent a survey with questions about demographics, career, background, and training both for musculoskeletal radiology and for the fellowship director role., Results: A 57/81 (70%) of program directors responded, representing 27 different states with a range of 1-9 fellowship positions. Nearly half are in their forties (48%) with most identifying as White (67%) followed by Asian (30%). The majority are male (72%) with over half (60%) remaining at the institution where they completed prior training. Over half plan to change roles within 5 years and do not feel adequately compensated. Top qualities/skills identified as important for the role include effective communication, being approachable, and clinical excellence. Other than clinical excellence, most do not report formal training in skills identified as important for the role., Conclusions: Given the high amount of interaction with trainees, program directors play a key role in the future of our subspecialty. The low diversity among this group, the lack of formal training, and the fact that most do not feel adequately compensated could limit mentorship and recruitment. Program directors identified effective communication, organizational/planning skills, and conflict resolution as the top skills they would benefit from formal training., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: To compare rotator cuff (RC) muscle cross-sectional areas (CSA) in subjects with adhesive capsulitis (AC) to age- and sex-matched controls., Materials and Methods: We retrospectively analyzed 97 shoulder MRIs or MR arthrography studies, of which 42 were clinically diagnosed with AC (27 female, 15 male) and 55 were age- and sex-matched controls (38 female, 17 male). All AC subjects underwent imaging ≥ 6 months after symptom onset. All imaging was examined to exclude RC full-thickness tears and prior surgery. A standardized T1 sagittal MR image was segmented in each subject to obtain the CSA of subscapularis (SSC), supraspinatus (SSP), and infraspinatus (ISP) muscles. Differences in CSAs between AC and control subjects were analyzed by sex (females and males separately) and all subjects combined., Results: AC females had significantly decreased SSC (P = 0.002) and total (P = 0.006) CSAs compared to controls. Male AC subjects showed decreased SSC (P = 0.044), SSP (P = 0.001), and total (P = 0.005) CSAs. Across all subjects, male and female, the AC cohort had significantly decreased SSC (P = 0.019) and total (P = 0.029) CSAs compared to controls., Conclusion: Decreased RC muscle CSAs were present in AC subjects with ≥ 6 months of symptom duration, with decreased SSC and total CSAs in male and female subjects, and decreased SSP CSA in males., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Purpose: To determine the added value of computed tomography (CT) to identify severe hip osteoarthritis (OA)., Materials and Methods: A retrospective query of all cases of hip or knee arthroplasty planning CTs between January 2018 and March 2022 was performed. Age, sex, and symptoms were collected from the medical record. CTs were evaluated for the degree of osteoarthritis and classified using an adapted Kellgren-Lawrence (KL) grading system in the anterior, posterior, superior, and superomedial hip. Frontal hip or pelvis radiographs within 1 year of the CT were also graded., Results: There were 265 eligible hips in 178 subjects, age 66 ± 11 (range 31-93) years, with 85/178 (48%) males and 93/178 (52%) females, and 127/265 (48%) right and 138/265 (52%) left hips. The posterior hip joint was the most common location for grade 2/3 OA (20%), followed by superior hip joint (14%). Anterior or posterior grade 2/3 OA occurred concurrently with superior or superomedial grade 2/3 OA in 32/68 (47%) of hips. Grade 2/3 OA was detected on CT more commonly than on XR both in the superior (14 vs 8.6%, P = 0.0016) and superomedial (8.7 vs 4.8%, P = 0.016) hip joint. Of the 71 symptomatic hips, 22 (31%) hips demonstrated either anterior and/or posterior grade 2/3 OA on CT, and 9 (9/22, 41%) of these hips had superior or superomedial grade 0/1 OA., Conclusion: CT may be warranted when the patient has pain suggestive of osteoarthritis not detected on radiographs., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: The purposes of this study were (1) to establish the feasibility and safety of an imaging-guided technique for intraosseous pressure (IOP) measurement in a large cohort of patients, and (2) to compare IOP values between normal and diseased bone marrow., Methods: Adult patients undergoing CT-guided marrow biopsy were prospectively and consecutively enrolled from November 2020 to February 2022. IOP measurements were obtained connecting the biopsy needle to a monitoring device using a standard arterial line setup. Clinical data including sex, age and pathology results were obtained. Student t test and Pearson correlation were used for continuous variables comparisons. Univariable analyses were performed using Fisher's exact test. A P value of .05 was considered statistically significant., Results: A total of 139 participants were initially enrolled, and four were excluded during technique optimization. There were no complications related to the measurement technique. Ninety participants (90/135, 67%) had histology confirming marrow pathology. The participants in the diseased marrow group were older than those in the normal marrow group (63 ± 14 vs. 55 ± 14 years; P < .01). There was no difference in mean IOP between both groups (66 ± 23 vs. 64 ± 28 mmHg; P = .69). There was no correlation between mean arterial blood pressure and mean IOP (P = .08)., Conclusion: There was no difference in IOP measurements between patients with normal and diseased marrow undergoing CT-guided biopsy. IOP does not appear to be influenced by systemic blood pressure. No complication occurred during the procedures., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Purpose: The purpose of this systematic review is to evaluate the current literature on the use of image-guided corticosteroid injections in the treatment of patients with knee and hip OA., Evidence Acquisition: We conducted a comprehensive literature search through June 30, 2022. Publication type, study design, imaging guidance modality, osteoarthritis severity, number of injections, steroid type and dose, anesthetic type and dose, the total number of patients, follow-up intervals, and measured outcomes were extracted from the included studies., Evidence Synthesis: There were 23 included studies (10 hips, 12 knees, 1 both hip and knee). Hip injections were found to be effective in treating short- and long-term pain and more effective than hyaluronic acid, Mepivacaine, NSAIDs, and normal saline in terms of improvement in pain and/or function. There was less impact on QoL. Knee injections were found either to have little or no impact or were similar or inferior to comparison injections (intra-articular hyaluronic acid, PRP, NSAIDs, normal saline, adductor canal blocks). Study data could not be aggregated because the corticosteroid types and doses, methods of outcome assessment, and follow-up time points varied widely., Conclusion: Our systematic review found generally positive outcomes for the hip, but overall negative outcomes for the knee, although hip injections may carry a risk of serious adverse outcomes. A larger trial with uniform methodology is warranted. Specific studies on the adverse effects of corticosteroid injections are also warranted., (© 2022. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Objective: To develop, train, and test a convolutional neural network (CNN) for detection of spinal lytic lesions in chest, abdomen, and pelvis CT scans., Materials and Methods: Cases of malignant spinal lytic lesions in CT scans were identified. Images were manually segmented for the following classes: (i) lesion, (ii) normal bone, (iii) background. If more than one lesion was on a single slice, all lesions were segmented. Images were stored as 128×128 pixel grayscale, with 10% segregated for testing. The training pipeline of the dataset included histogram equalization and data augmentation. A model was trained on Keras/Tensorflow using an 80/20 training/validation split, based on U-Net architecture. Additional testing of the model was performed on 1106 images of healthy controls. Global sensitivity measured detection of any lesion on a single image. Local sensitivity and positive predictive value (PPV) measured detection of all lesions on an image. Global specificity measured false positive rate in non-pathologic bone., Results: Six hundred images were obtained for model creation. The training set consisted of 540 images, which was augmented to 20,000. The test set consisted of 60 images. Model training was performed in triplicate. Mean Dice scores were 0.61 for lytic lesion, 0.95 for normal bone, and 0.99 for background. Mean global sensitivity was 90.6%, local sensitivity was 74.0%, local PPV was 78.3%, and global specificity was 63.3%. At least one false positive lesion was noted in 28.8-44.9% of control images., Conclusion: A task-trained CNN showed good sensitivity in detecting spinal lytic lesions in axial CT images., (© 2023. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Purpose: To compare diagnostic yield and utility of a novel core biopsy needle (NCBN) with shortened tip dead space for percutaneous musculoskeletal biopsies with an established core biopsy needle (ECBN)., Methods: This study was IRB approved and HIPAA compliant. All percutaneous biopsies using an NCBN performed between July 2020 and August 2021 were retrospectively reviewed. Data on patient demographics, biopsy technique, biopsy needle, and histopathology were collated., Results: Thirty-six patients were included in this study, 16 (44%) undergoing biopsy with both an NCBN and an ECBN, and 20 (56%) with an NCBN only. All 36 NCBN biopsies were 16 gauge. Fifteen (94%) of the ECBN biopsies were 14 gauge, and 1 (6%) was 16 gauge. Thirty-four (94%) of the NCBN and 15 (94%) of the ECBN biopsies were diagnostic. No adverse events were identified., Conclusion: Both the NCBN and ECBN have high diagnostic rates. No adverse events were identified. NCBN could be considered for biopsy of lesions limited by anatomic location or near adjacent critical structures., (© 2022. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

The purpose of this article is to present algorithms for the diagnostic management of solitary bone lesions incidentally encountered on computed tomography (CT) and magnetic resonance (MRI) in adults. Based on review of the current literature and expert opinion, the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology (SSR) proposes a bone reporting and data system (Bone-RADS) for incidentally encountered solitary bone lesions on CT and MRI with four possible diagnostic management recommendations (Bone-RADS1, leave alone; Bone-RADS2, perform different imaging modality; Bone-RADS3, perform follow-up imaging; Bone-RADS4, biopsy and/or oncologic referral). Two algorithms for CT based on lesion density (lucent or sclerotic/mixed) and two for MRI allow the user to arrive at a specific Bone-RADS management recommendation. Representative cases are provided to illustrate the usability of the algorithms., (© 2022. The Author(s).)

Purpose: The aim of this study is to evaluate the safety and effectiveness of CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histiocytosis (LCH) in a multi-institutional study., Materials and Methods: This IRB-approved study included patients from three institutions. We retrospectively reviewed clinical, procedural, and imaging data for corticosteroid injections performed to treat osseous LCH. Location of the lesion, lesion maximum dimension and volume, corticosteroid type and dose, and time interval between injection and change in lesion size/volume and symptoms were recorded. Generalized estimating equations (accounting for multiple lesions per subject) were used to evaluate the association between predictors (dose, maximum lesion dimension, and lesion volume) and outcomes (time to partial and complete radiographic resolution, and time to pain control). This analysis was adjusted by anatomic site., Results: Forty corticosteroid injections were performed in 36 patients (20 (56%) females, and 16 (44%) males, ages 12 ± 11 (2-57) years). Mean lesion maximum dimension was 3.2 ± 1.7 cm, and volume was 10 ± 17 cm 3 . Imaging and clinical follow-up were available for 22/40 (55%) and 34/40 (85%) of injections, respectively. All lesions responded to corticosteroid injection. Times to partial and complete imaging resolution were 13 ± 9 and 32 ± 13 weeks, respectively, and time to pain resolution was 22 ± 14 weeks. There were no complications., Conclusion: CT-guided corticosteroid injection is a safe and effective treatment for LCH. Pain resolution was achieved in all patients and imaging did not show progressive disease in any of the patients., (© 2021. ISS.)

Developments in artificial intelligence have the potential to improve the care of patients with musculoskeletal tumors. We performed a systematic review of the published scientific literature to identify the current state of the art of artificial intelligence applied to musculoskeletal oncology, including both primary and metastatic tumors, and across the radiology, nuclear medicine, pathology, clinical research, and molecular biology literature. Through this search, we identified 252 primary research articles, of which 58 used deep learning and 194 used other machine learning techniques. Articles involving deep learning have mostly involved bone scintigraphy, histopathology, and radiologic imaging. Articles involving other machine learning techniques have mostly involved transcriptomic analyses, radiomics, and clinical outcome prediction models using medical records. These articles predominantly present proof-of-concept work, other than the automated bone scan index for bone metastasis quantification, which has translated to clinical workflows in some regions. We systematically review and discuss this literature, highlight opportunities for multidisciplinary collaboration, and identify potentially clinically useful topics with a relative paucity of research attention. Musculoskeletal oncology is an inherently multidisciplinary field, and future research will need to integrate and synthesize noisy siloed data from across clinical, imaging, and molecular datasets. Building the data infrastructure for collaboration will help to accelerate progress towards making artificial intelligence truly useful in musculoskeletal oncology., (© 2021. ISS.)

Purpose: To develop a deep convolutional neural network capable of detecting spinal sclerotic metastases on body CTs., Materials and Methods: Our study was IRB-approved and HIPAA-compliant. Cases of confirmed sclerotic bone metastases in chest, abdomen, and pelvis CTs were identified. Images were manually segmented for 3 classes: background, normal bone, and sclerotic lesion(s). If multiple lesions were present on a slice, all lesions were segmented. A total of 600 images were obtained, with a 90/10 training/testing split. Images were stored as 128 × 128 pixel grayscale and the training dataset underwent a processing pipeline of histogram equalization and data augmentation. We trained our model from scratch on Keras/TensorFlow using an 80/20 training/validation split and a U-Net architecture (64 batch size, 100 epochs, dropout 0.25, initial learning rate 0.0001, sigmoid activation). We also tested our model's true negative and false positive rate with 1104 non-pathologic images. Global sensitivity measured model detection of any lesion on a single image, local sensitivity and positive predictive value (PPV) measured model detection of each lesion on a given image, and local specificity measured the false positive rate in non-pathologic bone., Results: Dice scores were 0.83 for lesion, 0.96 for non-pathologic bone, and 0.99 for background. Global sensitivity was 95% (57/60), local sensitivity was 92% (89/97), local PPV was 97% (89/92), and local specificity was 87% (958/1104)., Conclusion: A deep convolutional neural network has the potential to assist in detecting sclerotic spinal metastases., (© 2021. ISS.)

Background and Purpose: Lumbar spine MRI can help guide the choice of corticosteroid injection in pain management. We investigated whether patient-reported symptom information from a questionnaire could improve agreement in the choice of type, level, and side of injection., Materials and Methods: In this prospective observational study, 120 patients (median age 64, 70 men) were recruited from patients referred for pain management. After informed consent, they completed electronic questionnaires that obtained symptom information for later use during MRI reviews. In 3 research arms, 6 radiologists chose injections that would ideally deliver corticosteroid to the presumed sources of pain in (1) MRI studies reviewed with symptom information from questionnaires, (2) MRI studies reviewed without symptom information, and (3) MRI reports. Blinded to questionnaire results, radiologists providing clinical care and interviewing patients chose ideal therapeutic injections to establish reference standards. Injections were categorized by type, level, and side and compared using percent agreement and kappa statistics. Interreading agreement was analyzed., Results: Compared to the reference standard, kappa agreements for injection types, levels, and sides were almost perfect when MRIs were reviewed knowing symptoms (0.85-0.93), fair without symptoms (0.23-0.35) (all P < .001) and fair in MRI reports (0.24-0.36) (all P < .001). Interreading kappa agreements were almost perfect knowing symptoms (0.82-0.90), but only moderate without symptoms (0.42-0.49) (all P < .001)., Conclusions: Radiologists reviewing lumbar spine MRI converged on the type, level, and side of ideal therapeutic injection whether they obtained symptom information from direct patient interview or electronic questionnaire. Observer agreement was significantly lower without symptom information., (© 2021. ISS.)

Objective: Pulsatile intra-osseous pressures result in bone remodeling, and therefore may affect lesion growth and response to treatment. However, there is no known method used to measure intra-osseous pressures. The purpose of this study is to describe a novel image-guided technique for measuring intra-osseous pressures., Materials and Methods: This study was IRB-approved and HIPAA compliant. Written informed consent was obtained. Intra-osseous pressure measurements were performed during a CT-guided bone marrow biopsy in eight patients (6 male, 2 female) with mean age 66 ± 13 years (median 72, range 45-87) and suspected or known bone marrow disease. Bone marrow pressure measurements were obtained connecting the biopsy needle to a dedicated monitor using a standard arterial line setup. Monitor data was collected at 5-s intervals in order to record continuous pressure measurements for 2 min., Results: Pressure measurements were successfully performed in all 8 patients. The mean bone marrow pressures were 36.8 ± 7.2 mmHg (median 37.7, range 24.7-47.4). The peak and trough pressures varied by 11%, and the standard deviation of mean pressure measurement varied by 18%. Our findings for marrow pressure measures most closely approximate the pressure profile of the venous system., Conclusion: We describe a novel and minimally invasive technique able to provide functional data of bone marrow. This technique has the potential to provide insights into normal and diseased bone marrow and may be helpful to evaluate features of cystic and vascular tumors that may be amenable to percutaneous treatments.

Objective: To assess the readability of patient-targeted online information on musculoskeletal radiology procedures., Methods: Eleven common musculoskeletal radiology procedures were queried in three online search engines (Google, Yahoo!, Bing). All unique patient-targeted websites were identified (n = 384) from the first three pages of search results. The reading grade level of each website was calculated using 6 separate validated metrics for readability assessment. Analysis of word and sentence complexity was also performed. Results were compared between academic vs. non-academic websites and between websites found on different pages of the search results. Statistics were performed using a t test., Results: The mean reading grade level across all procedures was 10th-14th grade. Webpages for nerve block were written at a higher reading grade level on non-academic websites (p = 0.025). There was no difference in reading grade levels between academic and non-academic sources for all other procedures. There was no difference in reading grade levels between websites found on the first page of search results compared with the second and third pages. Across all websites, 16-22% of the words used had 3+ syllables and 31-43% of the words used had 6+ characters (complex words); 13-24% of the sentences used had 22+ words (complex sentences)., Conclusion: Patient-targeted online information on musculoskeletal radiology procedures are written at the 10th-14th grade reading level, which is well beyond the AMA and NIH recommendation. Readability can be lowered by decreasing text complexity through limitation of high-syllable words and reduction in word and sentence length.

Background: Musculoskeletal pain is a debilitating problem treated with image-guided corticosteroid injections. During the COVID-19 pandemic, multiple societies issued caution statements because of the unknown effect of corticosteroids on the patient's immune system. The purpose is to determine if image-guided corticosteroid injections administered during the COVID-19 lockdown phase were associated with a higher infection rate compared to the general population., Materials and Methods: In a prospective study, patients undergoing image-guided corticosteroid injections for pain management during the lockdown phase between April 15 and May 22, 2020, were enrolled. One month after the injection, patients were surveyed by telephone for any COVID-19-related symptoms, and the electronic medical record (EMR) was reviewed for symptoms and test results., Results: Seventy-one subjects were recruited, 31 (44%) females, 40 (56%) males, ages 58 ± 17 (20-92) years. Follow-up was available in 66 (93%) of subjects, 60 (91%) by phone survey and EMR, 6 (9%) by EMR only, 45 ± 22 (19-83) days after injection. One (1/66, 1.52%; 95% CI 0.04-8.2%) 25-year-old male subject developed symptomatic infection 19 days after a tibiotalar injection. The prevalence of COVID-19 cases in the state of Massachusetts was 0.91% (62,726/6,892,503) during the study period. There was no significant difference in the rate of occurrence of new cases of COVID-19 infection between the corticosteroid injection group and the general population (p = 0.44)., Conclusion: Image-guided corticosteroid injections for pain management performed during the lockdown phase of the COVID-19 pandemic were not associated with a higher infection rate compared to the general population.

Purpose: To compare the microbiology results and needle gauge for CT-guided biopsies of suspected discitis-osteomyelitis., Methods: All CT-guided biopsies performed for suspected discitis-osteomyelitis at our institution between 2002 and 2019 were reviewed. Biopsy location, needle type and gauge, microbiology, pathology, and clinical and imaging follow-up were obtained through chart review. Yield, sensitivity, specificity, and accuracy were calculated. A pairwise analysis of different needle gauges was also performed with calculations of odds ratios. Naïve Bayes predictive modeling was performed., Results: 241 (age: 59 ± 18 years; 88 [35%] F, 162 [65%] M) biopsies were performed. There were 3 (1%) 11 gauge (G), and 13 (5%) 12-G biopsies; 23 (10%) 13-G biopsies; 75 (31%) 14-G biopsies; and 90 (37%) 16-G, 33 (14%) 18-G, and 4 (2%) 20 G biopsies. True disease status (presence of infection) was determined via either pathology findings (205, 86%) or clinical and imaging follow-up (36, 14%). The most common true positive pathogen was Staphylococcus aureus (31, 33%). Overall biopsy yield, sensitivity, specificity, and accuracy were 39%, 56%, 89%, and 66%, respectively. Pooled biopsy yield, sensitivity, specificity, and accuracy was 56%, 69%, 71%, and 69% for 11-13-G needles and 36%, 53%, 91%, and 65% for 14-20-G needles, respectively, with an odds ratio between the two groups of 2.29 (P = 0.021). Pooled biopsy yield, sensitivity, specificity, and accuracy was 48%, 63%, 85%, and 68% for 11-14-G needles and 32%, 49%, 91%, and 64% for 16-20-G needles, respectively, with an odds ratio between the two groups of 2.02 (P = 0.0086)., Conclusion: The use of a larger inner bore diameter/lower gauge biopsy needle may increase the likelihood of culturing the causative microorganism for CT-guided biopsies of discitis-osteomyelitis.

Purpose: To determine the effect of intra-articular corticosteroid injections on lumbar spine trabecular density., Materials and Methods: This retrospective study was IRB-approved and HIPAA-compliant. We identified 50 patients (26 F, 24 M, mean age 69 ± 14 years) who had undergone at least three medium or large joint corticosteroid injections using insoluble corticosteroids and a subsequent non-contrast abdominal CT within 5 years of the first injection. About 126 age- and sex-matched controls without history of prior corticosteroid use who had undergone non-contrast abdominal CT were identified. Cumulative corticosteroid dose was calculated. Density measurements (HU) of trabecular bone of L1 to L4 were performed, and measurements of L1 were compared to established normative data. Groups were compared using a two-sided paired t-test or a chi-squared test. Linear regression analysis between cumulative corticosteroid dose and trabecular density was performed., Results: Patients underwent a mean of 4 corticosteroid injections (range 3 to 11) with a mean cumulative corticosteroid dose of 232 ± 100 mg triamcinolone equivalent (range 120 mg to 480 mg). There was no significant difference in trabecular density of L1 to L4 between cases and controls, and there was no significant difference in trabecular density at L1 compared to normative data (p > 0.2). There was no association between cumulative intra-articular corticosteroid dose and mean lumbar trabecular density (p > 0.3)., Conclusion: Patients who underwent repetitive intra-articular insoluble corticosteroid injections showed no increased risk of bone loss compared to controls. Cumulative intra-articular corticosteroid dose was not associated with lumbar trabecular density.

Purpose: To determine the number of days to positive CT-guided biopsy sample culture in patients with discitis-osteomyelitis., Methods: Our study was IRB approved and HIPAA compliant. All CT-guided biopsies performed for acute discitis-osteomyelitis with positive microbiology between 2002 and 2018 were reviewed. Microbiological organism and days to positive biopsy were documented. Mean, median, skew, and standard deviation were calculated. The proportion of positive cultures that become positive after each day has elapsed was also calculated., Results: There were 96 true positive cultures, with 64 (67%) male and 32 (33%) female, ages 57 ± 18 (range 19-87) years. Overall, including all culture results, the mean number of days to positive culture was 2.9 ± 3.5 days. The median number of days was 2, with a positive skew of 2.9. At days 1, 2, 3, 4, and 5, 48%, 68%, 78%, 85%, and 89%, respectively, of biopsy samples had a positive microbiology culture., Conclusion: Approximately three-quarters of discitis-osteomyelitis pathogens will be identified by biopsy sample culture by 3 days after CT-guided biopsy. This finding should be considered if planning for a repeat biopsy in the setting of a negative microbiology culture.

Purpose: To determine the value of anesthetic injection during hip MR arthrography (anesthetic MRA) to differentiate between intra- and extra-articular pathology in patients with hip pain., Materials and Methods: This retrospective study was IRB-approved and HIPAA-compliant. We included 75 consecutive adult patients (46 women, mean age 38 ± 13 years) who were referred for MRA. All patients underwent a focused hip examination including active flexion, passive flexion, and passive flexion with internal and external rotation, immediately prior to injection. Anesthetic MRA was performed following fluoroscopically guided intra-articular injection of contrast mixed with anesthetic. Following the injection, the hip examination was repeated, and the pain response was recorded. Clinical records, including response to corticosteroid injections, physical therapy notes, and operative reports were reviewed for verification of intra- and extra-articular pathology as the source of hip pain (gold standard). The positive (PPV) and negative predictive values (NPP) of anesthetic MRA to differentiate between intra- and extra-articular pathology were calculated., Results: On MRI, 41 patients had only intra-articular and 5 patients only extra-articular pathology, while 29 patients had both, intra- and extra-articular pathology. Forty-three patients had pain relief and 32 patients had no pain relief after anesthetic injection. PPV of anesthetic MRA to detect intra-articular pathology was 91% and NPV was 67%., Conclusion: Anesthetic MRA can be used as an adjunct to define the origin of hip pain. A positive response suggests intra-articular pathology which can be helpful to localize the source of pain in equivocal cases where both intra- and extra-articular pathology are evident on MRI.

Purpose: To investigate the role of music on subjects undergoing routine image-guided musculoskeletal corticosteroid injections and its effect on post-procedure pain and subjective overall experience., Materials and Methods: This prospective study was IRB-approved and HIPAA-compliant. A total of 126 subjects referred for outpatient image-guided musculoskeletal corticosteroid injections were enrolled in the study and randomized into a music offered group ((+)MO) and a no music offered group ((-)MO). (+)MO subjects were given the opportunity to listen to music during their corticosteroid injection. All subjects were then given an anonymous survey on which they recorded their pre-procedural and post-procedural pain on a scale from 0 to 9 and rated their overall experience and how likely they were to recommend our department for musculoskeletal procedures on scales from 1 to 5., Results: (+)MO subjects had significantly lower post-procedural pain (p = 0.013) and significantly greater decrease in pain (p = 0.031) compared to (-)MO subjects. Among the (+)MO subjects, there was no statistically significant difference in post-procedure pain (p = 0.34) or change in pain (p = 0.62) if music was accepted or declined. However, subjects who listened to music did have lower post-procedural pain compared to those who did not listen to music (p = 0.012), although the differences in the decrease of pain between the two groups did not quite reach statistical significance (p = 0.062)., Conclusions: Playing music during image-guided musculoskeletal corticosteroid injections may reduce patients' post-procedure pain. Offering patients some measure of control over their procedure may be a factor that contributes to decreased post-procedure pain as well.

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.

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.

Objective: To describe an ultrasound guided injection technique for diagnosing and treating posteromedial knee friction syndrome, which occurs between the sartorius/gracilis tendons and medial femoral condyle (MFC)., Materials and Methods: Our study was IRB-approved and HIPAA-compliant. We identified patients via a retrospective review of medical records and MRI with posteromedial knee pain and isolated edema between MFC and sartorius/gracilis tendons and no evidence for meniscal tear, ruptured Baker's cyst or degenerative joint disease. Patients were referred for an ultrasound-guided procedure to inject anesthetic and corticosteroid at the site of edema. Procedures were evaluated for technical success, which was defined as satisfactory identification of the injection site and adequate delivery of medication. Follow-up was available up to 8 weeks after the procedure to determine the response and any potential complications., Results: Fourteen subjects with MRI and symptoms of posteromedial knee friction syndrome underwent 14 injections. Technical success was achieved in all procedures, with no complications. At 8 weeks' follow-up, 92% of patients had symptom improvement. VAS before and 8 weeks after the procedure changed from 5.2 ± 2.7 to 0.9 ± 2.1 (p = 0.0002), respectively., Conclusion: Ultrasound-guided injection of edema between the MFC and sartorius/gracilis tendons supports the diagnosis of a posteromedial knee friction syndrome and successfully treats its associated symptoms.

Objective: To correlate MRI findings of patients with posterior cruciate ligament (PCL) injury and surgical management., Materials and Methods: A retrospective search yielded 79 acute PCL injuries (36 ± 16 years old, 21 F, 58 M). Two independent readers graded PCL tear location (proximal, middle, or distal third) and severity (low-grade or high-grade partial/complete) and evaluated injury of other knee structures. When available, operative reports were examined and the performed surgical procedure was compared with injury grade, location, and presence of associated injuries., Results: The most commonly injured knee structures in acute PCL tears were posterolateral corner (58/79, 73%) and anterior cruciate ligament (ACL) (48/79, 61%). Of the 64 patients with treatment information, 31/64 (48%) were managed surgically: 12/31 (39%) had PCL reconstruction, 13/31 (42%) had ACL reconstruction, 10/31 (32%) had posterolateral corner reconstruction, 9/31 (29%) had LCL reconstruction, 8/31 (26%) had meniscectomy, and 8/31 (26%) had fixation of a fracture. Proximal third PCL tear and multiligamentous injury were more commonly associated with surgical management (P < 0.05). Posterolateral and posteromedial corner, ACL, collateral ligament, meniscus, patellar retinaculum, and gastrocnemius muscle injury, and fracture were more likely to result in surgical management (P < 0.05). Patients with high-grade partial/complete PCL tear were more likely to have PCL reconstruction as a portion of surgical management (P < 0.05)., Conclusions: Location of PCL tear and presence of other knee injuries were associated with surgical management while high-grade/complete PCL tear grade was associated with PCL reconstruction. MRI reporting of PCL tear location, severity, and of other knee structure injuries is important for guiding clinical management.

Objective: To evaluate clinical and radiological features of pathology-proven extraskeletal osteosarcomas., Methods: This retrospective study was IRB-approved and HIPAA-compliant. Our pathology database was queried for cases of extraskeletal osteosarcoma. Tumor location, size, imaging appearance, presence of metastases, and clinical outcome were documented., Results: Nineteen patients met inclusion criteria (age 59 ± 15 (range 28-85) years; 15 male, 4 female). Tumors occurred in the lower extremities (12 out of 19, 63%), pelvis/gluteal region (3 out of 19, 16%), upper extremity (2 out of 19, 5%), thorax (1 out of 19, 5%), and neck (1 out of 19, 5%). Two out of 19 (11%) patients had undergone radiation to the tumor site previously. According to pathology, 16 out of 19 tumors were high-grade (84%). Tumors presented as soft-tissue masses measuring 9.5 ± 6.8 (2-29) cm. Tumor mineralization was present in 5 out of 19 cases (26%) and local invasion was found in 1 out of 19 cases (6%). On MRI, tumors typically appeared hyperintense on T2-weighted sequences with enhancement in 15 out of 15 (100%) contrast-enhanced studies, and with central necrosis in 10 out of 19 (53%) cases. Low-grade tumors were smaller (<4 cm; 3 out of 3, 100%) and lacked central necrosis (3 out of 3, 100%). 8 out of 19 patients (42%) had metastases, most commonly to the lung (7 out of 19, 37%) and bone (2 out of 19,11%). Two out of 8 patients (25%) with metastases and 8 out of 11 (73%) without metastases achieved recurrence-free survival (mean follow-up 3.8 ± 4.0 [0.2-14.2]) years. No metastases or deaths occurred in patients with low-grade histology., Conclusions: Extraskeletal osteosarcomas are rare, typically high-grade malignancies that commonly metastasize to lung and bones. Low-grade tumors and those without metastases have a good prognosis. MRI appearance is nonspecific, with T2 hyperintense signal and heterogeneous enhancement. Unlike conventional osteosarcoma, mineralization is rare.

Objective: To evaluate methods of CT-guided sacroiliac joint sampling in patients with suspected infection., Materials and Methods: All CT-guided sacroiliac joint sampling procedures for suspected infection were reviewed for sampling type (aspiration, lavage aspiration, biopsy), microbiology results, and clinical and imaging follow-up. The primary gold standard was anatomic pathology. If pathology was not available, then positive blood culture with the same organism as SIJ sampling, imaging and clinical follow-up, or clinical follow-up only were used. Anterior and posterior joint distention was evaluated by MRI within 7 days of the procedure., Results: A total of 34 patients (age 39 ± 20 (range, 6-75) years; 21 F, 13 M) were included. Aspiration samples only were obtained in 13/34 (38%) cases, biopsy samples only in 9/34 (26%) cases, and both samples in 12/34 (35%) cases. There was an overall 54% sensitivity and 86% specificity. For the aspiration samples, sensitivity and specificity were 60 and 81%, respectively, compared to 45 and 90% for the biopsy samples. In cases with both samples, biopsy did not add additional microbial information. Seventeen (17/34, 50%) patients had an MRI. The anterior joint was more distended than the posterior joint in 15/17 (88%) of patients, and this difference was significant (P = 0.0003). All of these 17 patients had an attempted aspiration by a posterior approach; 6/17 (35%) resulted in a successful aspiration., Conclusions: Aspiration of the sacroiliac joint has a higher sensitivity than biopsy and should always be attempted first. MRI may be helpful for procedure planning.

Purpose: Osseous metastases often undergo an osteoblastic healing response following chemotherapy. The purpose of our study was to demonstrate the quantitative CT changes in attenuation of osseous metastases before and after chemotherapy., Materials and Methods: Our study was IRB approved and HIPAA compliant. Our cohort consisted of 86 consecutive cancer patients with contrast-enhanced CTs before and 14 ± 2 (12-25) months after initiation of chemotherapy (60 ± 11 years, 36 males, 50 females). The average and maximum metastasis attenuations were measured in Hounsfield units (HU) by two readers. Treatment effects were assessed using paired t-tests and Fisher exact tests. Intraclass correlation coefficients (ICCs) were calculated. Patient records were reviewed to determine the patient's clinical status (worse, unchanged, or improved) at the time of follow-up CT., Results: The distribution of lesion types was as follows: lytic (30/86, 35%), blastic (43/86, 50%), and mixed lytic-blastic (13/86, 15%). There was a significant increase in average and maximum CT attenuation of metastases following chemotherapy for all patients, which remained statistically significant when stratified by lesion type, clinical status (worsening or improving/stable), cancer type (breast, lung), and radiation therapy (P < 0.05). In a subgroup of patients whose osseous metastases decreased in average attenuation (14/86, 16%), more patients had a worse clinical status (11/14, 79%) (P = 0.02). ICC was almost perfect for average attenuation and substantial for maximum attenuation., Conclusion: Quantitative assessment of osseous metastatic disease using CT attenuation measurements demonstrated a statistically significant increase in attenuation more than 12 months after initiation of chemotherapy.

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.

Objective: To study anatomical variations on MRI of the first extensor compartment of the wrist in DeQuervain tenosynovitis (DQT)., Materials and Methods: A retrospective search for DQT patients yielded 47 subjects (51 ± 15 years, 36 female, 11 male). The age-matched control group (normal first extensor compartment) was 49 ± 15 years (29 female, 18 male). Two independent readers reviewed: the number of abductor pollicis longus (APL) tendon slips, tendon sheath septations (compartmentalization), and APL and EPB cross-sectional area (CSA) at the radial styloid. A tendon slip was defined as a discrete structure for ≥5 contiguous slices with its own insertion., Results: The distribution of APL tendon slips was different for the DQT and control groups (Reader 1/Reader 2: P = 0.0001 and 0.001). The most common arrangement for both groups was two APL tendon slips. One tendon slip was less common (P = 0.03 and 0.1) and compartmentalization was more common (P = 0.003; < 0.0001) for the DQT group than the control group. There was no difference in tendon slip insertions on one or multiple bones (P = 0.1; 0.7). APL and EPB compartment CSAs were also higher for the DQT group (combined first extensor compartment area: 21.3 ± 7.6 mm 2 ; 21.0 ± 7.1) than the control group (17.2 ± 3.8; 17.1 ± 3.9) (P = 0.002; 0.002)., Conclusion: We found a statistically significantly increased proportion of supernumerary tendon slips and compartmentalization of the first extensor compartment in patients with DQT and greater CSA of the first extensor compartment at the radial styloid, consistent with previous anatomical, surgical, and ultrasound studies.

Objectives: To determine the efficacy and safety of percutaneous calcitonin and steroid injection in the treatment of aneurysmal bone cysts (ABCs)., Materials and Methods: Our study was IRB-approved and HIPAA-compliant. We reviewed pre- and post-procedural imaging studies and medical records of all CT-guided percutaneous injections of ABCs with calcitonin and steroid performed at our institution between 2003 and 2015., Results: Treatment success based on imaging was categorized as substantial (51-100 %), partial (1-50 %), or none (0 %) by comparing radiographs of the lesion before and after treatment. Our study group comprised 9 patients (7 female, 2 male; mean age 19 ± 5 (range 12-25) years). ABCs were located in the pubis (n = 3), femur (n = 2), and humerus/scapula/ilium/sacrum (n = 1 for each). One patient did not have any clinical or imaging follow-up. For the other 8 patients, clinical and imaging follow-up ranged from 1 to 93 months (mean 16 ± 29 months). One patient had two injections, and 1 patient had three injections. Six out of eight patients (75 %) had complete symptomatic relief and 2 patients (25 %) had partial symptomatic relief after initial injection. Imaging follow-up revealed substantial imaging response in 4 out of 8 patients (50 %). There was a partial imaging response in 2 patients (25 %) and no imaging response in 2 out of 8 patients (25 %), and all 4 of these patients had local recurrence. There were no complications., Conclusion: Percutaneous CT-guided injection of ABCs with calcitonin and steroid is a safe and effective treatment. Lack of imaging response may necessitate more aggressive treatment to minimize local recurrence.

Objective: To evaluate the therapeutic value, safety, and long-term clinical outcomes of percutaneous lumbar facet synovial cyst (LFSC) rupture., Materials and Methods: Our study was institutional review board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPAA)-compliant. The study group comprised 71 patients (44 women, mean age: 65 ± 17 years) who underwent CT- or fluoroscopy-guided percutaneous LFSC rupture. The technical success of LFSC rupture, the long-term clinical outcome, including repeat procedures or surgery, and imaging findings on MRI and CT were recorded., Results: Seventy-nine LFSC ruptures were performed in 71 patients. CT guidance was used in 57 cases and fluoroscopy guidance in 22 cases. LFSC rupture was technically successful in 58 out of 79 cases (73 %). Mean injection volume for cyst rupture was 3.6 ± 2.2 mL and a combination of steroid and anesthetic was injected in all cases. Over a mean follow-up time of 44 months, 12 % of patients underwent repeat cyst rupture, and 46 % eventually underwent surgery, whereas the majority of patients (55 %) experienced symptomatic relief and did not undergo surgery. There was no significant association between a successful outcome and age, sex, level, or size of LFSC (p > 0.1). LFSCs with T2 hypointensity were more likely to require surgery (p = 0.02). There was one complication, a bacterial skin infection that completely resolved following antibiotic therapy., Conclusion: Percutaneous LFSC rupture is an effective and safe nonsurgical treatment option for LFSC. More than half of treated patients were able to avoid subsequent surgery. Therefore, percutaneous LFSC rupture should be considered before surgical intervention.

Purpose: To compare the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections with respect to successful intra-articular needle placement, fluoroscopy time, radiation dose, and dose area product (DAP)., Materials and Methods: This retrospective study was IRB-approved and HIPAA-compliant. 498 fluoroscopically guided tibiotalar joint injections were performed or supervised by one of nine staff radiologists from 11/1/2010-12/31/2013. The injection approach was determined by operator preference. Images were reviewed on a PACS workstation to determine the injection approach (lateral mortise versus anterior midline) and to confirm intra-articular needle placement. Fluoroscopy time (minutes), radiation dose (mGy), and DAP (μGy-m(2)) were recorded and compared using the student's t-test (fluoroscopy time) or the Wilcoxon rank sum test (radiation dose and DAP)., Results: There were 246 lateral mortise injections and 252 anterior midline injections. Two lateral mortise injections were excluded from further analysis because no contrast was administered. Intra-articular location of the needle tip was documented in 242/244 lateral mortise injections and 252/252 anterior midline injections. Mean fluoroscopy time was shorter for the lateral mortise group than the anterior midline group (0.7 ± 0.5 min versus 1.2 ± 0.8 min, P < 0.0001). Mean radiation dose and DAP were less for the lateral mortise group than the anterior midline group (2.1 ± 3.7 mGy versus 2.5 ± 3.5 mGy, P = 0.04; 11.5 ± 15.3 μGy-m(2) versus 13.5 ± 17.3 μGy-m(2), P = 0.006)., Conclusion: Both injection approaches resulted in nearly 100% rates of intra-articular needle placement, but the lateral mortise approach used approximately 40% less fluoroscopy time and delivered 15% lower radiation dose and DAP to the patient.

We report on the dynamic sonographic findings of a 10-year-old avid female dancer who presented with symptoms of abrupt left hip motion and associated painful snapping sensation while performing lateral motions of the pelvis suggesting external snapping hip syndrome. Dynamic sonographic evaluation of both hips demonstrated that symptoms were due to gluteus maximus subluxation over the greater trochanter. This etiology of external snapping hip syndrome is rare with limited imaging descriptions in the literature. We present case history, physical examination, and dynamic ultrasound examination, including multiple still images and cine clips, comprehensively characterizing this uncommon source of external snapping hip syndrome.

Objective: To compare prevalence and patterns of intravertebral collateral enhancement in patients with and without central venous obstruction (CVO)., Materials and Methods: Chest CTs performed between 1/1/2000 and 12/15/2012 with reports containing terms indicating CVO were identified. All contrast enhanced CTs were examined for the presence of CVO and collateral venous pathways. If intravertebral collateral enhancement was present, the pattern was recorded as nodular, linear, or both., Results: In 209 suspected cases of CVO, 53 (25 %) were confirmed with obstruction and 156 (75 %) were without obstruction. In patients with CVO, 47 % (25/53) demonstrated collateral venous flow through an intravertebral marrow pathway compared to 5 % (8/156) of patients without CVO (P < 0.0001). The most common level of enhancement was the upper thoracic spine, involving only the vertebral body. Nodular, linear, and combined nodular-linear enhancement patterns were seen with similar frequency. Nodular intravertebral collateral enhancement was mistaken for sclerotic metastases in 33 % (3/9) of cases., Conclusion: Intravertebral collateral enhancement was seen in almost half the patients with CVO and when nodular enhancement is present, it is important to differentiate between metastatic lesions and enhancement related to CVO.

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.

Image-guided biopsies play an important role for pathologic diagnosis of bone tumors. Recently, motorized, battery powered bone marrow biopsy devices have been used to biopsy focal bone lesions with high accuracy. We present here two cases of densely blastic metastases where the biopsy sample could not be removed from the needle. These two cases suggest that if the lesion is densely blastic, then the sample should be small (<5 mm) to ensure that the biopsy specimen will not be stuck within the biopsy needle.

Objective: The superior transverse scapular ligament (STSL) forms the roof of the suprascapular notch, which is the most common location of entrapment of the suprascapular nerve, a cause of shoulder pain and weakness. The purpose of this study is to determine the frequency of visualization of the STSL on routine shoulder MRIs, to identify the sequences and imaging planes on which it is visualized most frequently, and to describe its typical MRI appearance, none of which have been previously addressed in the radiologic literature., Materials and Methods: One hundred twenty-one consecutive shoulder MRIs were reviewed for the presence or absence of the STSL, including the imaging plane and sequence that best depicted the ligament. Dimensions of the ligament were recorded., Results: Fifty four of 121 shoulder MRIs were technically adequate for visualization of the STSL, and it was identified on 51 of these studies (94%). There was no statistically significant difference between 1.5-T and 3-T systems. The best individual sequence for visualizing the STSL was the sagittal T1-weighted sequence, in which the STSL was visible on 75/80 technically adequate sequences (94%). The sagittal plane was the best plane for visualizing the STSL, in which it was visible on 65/69 technically adequate studies (94%). The STSL on average measured 12.8 ± 1.5 mm in transverse dimension., Conclusions: The STSL can be visualized on the majority of shoulder MRIs and is best seen on sagittal T1-weighted images on our imaging protocol. Evaluation of the STSL can potentially help in identifying pathologic conditions affecting the suprascapular nerve.

Purpose: To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT., Materials and Methods: Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT., Results: Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P =  .02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications., Conclusion: CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT.

Objective: To describe MRI features of an entity consisting of medial knee pain and edema between the posteromedial femoral condyle (PMFC), sartorius and/or gracilis tendons and determine whether reduced tendon-bone distances may account for these findings., Methods: We retrospectively identified MRI cases of edema between the PMFC, sartorius and/or gracilis tendons (25 subjects, 26 knees). Two musculoskeletal radiologists independently graded edema and measured the sartorius- and gracilis-PMFC distances and knee flexion angle. Age- and gender-matched subjects with normal knee MRIs (27 subjects, 27 knees) served as controls for measurements. Statistical analyses compared abnormal to control subjects., Results: Sartorius-PMFC and gracilis-PMFC spaces were narrower in abnormal compared to control subjects (1.6 ± 1.0 vs. 2.1 ± 1.2 mm, P = 0.04; 2.3 ± 2.0 vs. 4.6 ± 3.0 mm, P = 0.002, respectively). The knee flexion angle was similar between groups (P > 0.05). In subjects with clinical information, medial knee pain was the main complaint in 58 % (15/26) of abnormal subjects, with 42 % (11/26) having clinical suspicion of medial meniscal tear. Edema between the PMFC, sartorius and/or gracilis was mild in 54 % (14/26), moderate in 35 % (9/26) and severe in 12 % (3/26), and it was most frequent deep to both the sartorius and gracilis (50 %, 13/26)., Conclusions: Edema between the PMFC, sartorius and/or gracilis tendons identified on knee MRI may be associated with medial knee pain and may represent a friction syndrome.

Objective: To demonstrate the normal appearance of the ligamentum teres on MR arthrography (MRA) and evaluate the accuracy of MRA in detecting ligamentum teres tears with arthroscopic correlation., Materials and Methods: Institutional Review Board approval was obtained with a waiver for informed consent because of the retrospective study design. A total of 165 cases in 159 patients (111 females, 48 males; mean age 41 ± 12 years) who underwent both MRA and hip arthroscopy were evaluated for appearance of the ligamentum teres, including the size, number of bundles, and ligamentum teres tears. Marrow edema of the fovea capitis adjacent to the ligamentum teres insertion and the presence of hip plicae were also recorded., Results: The mean thickness and length of the ligamentum teres were 3.5 ± 1.5 mm and 25.2 ± 3.8 mm, respectively. Sensitivity, specificity, positive and negative predictive value, and accuracy of MRA for the detection of ligamentum teres tears were 78, 97, 74, 97, and 95%, respectively., Conclusion: MRA is an accurate method to evaluate the normal morphology and to detect tears of the ligamentum teres.

Objective: To assess MRI measures to quantify pelvic morphology that may predispose to ischiofemoral impingement (IFI). We hypothesized that patients with IFI have a wider interischial distance and an increased femoral neck angle compared with normal controls., Materials and Methods: The study was IRB-approved and complied with HIPAA guidelines. IFI was diagnosed based on clinical findings (hip or buttock pain) and ipsilateral edema of the quadratus femoris muscle on MRI. Control subjects did not report isolated hip/buttock pain and underwent MRI for surveillance of neoplasms or to exclude pelvic fractures. Two MSK radiologists measured the ischiofemoral (IF) and quadratus femoris (QF) distance, the ischial angle as a measure of inter-ischial distance, and the femoral neck angle. The quadratus femoris muscle was evaluated for edema. Groups were compared using ANOVA. Multivariate standard least-squares regression modeling was used to control for age and gender., Results: The study group comprised 84 patients with IFI (53 ± 16 years, 73 female, 11 male) and 51 controls (52 ± 16 years, 33 female, 18 male). Thirteen out of 84 patients (15%) had bilateral IFI. Patients with IFI had decreased IF and QF distance (p < 0.0001), increased ischial angle (p = 0.004), and increased femoral neck angle (p = 0.02) compared with controls, independent of age and gender., Conclusion: Patients with IFI have increased ischial and femoral neck angles compared with controls. These anatomical variations in pelvic morphology may predispose to IFI. MRI is a useful method of not only assessing the osseous and soft-tissue abnormalities associated with IFI, but also of quantifying anatomical variations in pelvic morphology that can predispose to IFI.