Clinical impact of whole-body MRI in staging and surveillance of patients with myxoid liposarcoma: a 14-year single-centre retrospective study.

OBJECTIVE: To assess the clinical impact of regular whole-body magnetic resonance imaging (WBMRI) surveillance in myxoid liposarcoma patients. METHODS: This was a retrospective cohort study of myxoid liposarcoma patients who underwent at least one WBMRI at our institution between October 2006 and December 2020. The effect of WBMRI on clinical management, namely treatment modification or additional diagnostic investigations was studied. A standardised WBMRI surveillance protocol was instituted in 2015. We compared patient outcomes for the metastatic patients who had and had not received regular WBMRI surveillance and performed survival analysis for both subgroups. RESULTS: Of the 56 patients (60.7% male, median age: 48.1 years) who underwent 345 WBMRI, 17 (30.3%) had metastases, and 168 WBMRI were performed in this group. The median imaging follow-up for the entire cohort was 35 months; the metastatic group had a median follow-up of 42 months. WBMRI changed the clinical management in 13 (76.5%) metastatic patients, with 33 instances of treatment modification. Thirty-five lesions were labelled 'indeterminate,' 16 (45.7%) had additional investigations/interventions, and 4 (11.4%) were confirmed to be metastatic. Twenty-one metastatic lesions were missed initially on WBMRI and confirmed on subsequent WBMRI, of which 5 (23.8%) were clinically significant. The 5-year survival since the detection of metastasis was better in the regular surveillance subgroup (85.7% vs. 45%), but this was not statistically significant (p = 0.068). Five patients (8.9%) developed their first metastasis more than 5 years after diagnosing the primary lesion. CONCLUSION: Regular WBMRI surveillance of myxoid liposarcoma patients considerably impacts clinical management by frequently influencing treatment decisions. CLINICAL RELEVANCE STATEMENT: WBMRI has been recently recommended as an imaging option for the staging and surveillance of myxoid liposarcoma patients. Our study highlights the impact of regular WBMRI surveillance on the clinical management of these patients and how it affects their survival.

Canadian Association of Radiologists Musculoskeletal System Diagnostic Imaging Referral Guideline.

The Canadian Association of Radiologists (CAR) Musculoskeletal System Expert Panel consists of musculoskeletal radiologists, a family physician, a sports and exercise medicine physician, emergency medicine physicians, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 25 musculoskeletal clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for 1 or more of these clinical/diagnostic scenarios. Recommendations from 41 guidelines (50 publications) and contextualization criteria in the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) for guidelines framework were used to develop 124 recommendation statements across the 25 scenarios related to the evaluation of the musculoskeletal system. This guideline presents the methods of development and the recommendations for imaging in the context of musculoskeletal pain, infection, tumors, arthropathies, metabolic bone disease, stress injuries, orthopedic hardware, avascular necrosis/bone infarction, and complex regional pain syndrome.

Imaging Utilization Patterns in the Follow-Up of Extremity Soft Tissue Sarcomas in the United States.

This study aimed to describe patterns of imaging utilization after resection of extremity soft tissue sarcoma in the United States, assess for potential disparities, and evaluate temporal trends. A retrospective cohort study using a national database of private payer claims data was performed to determine the utilization rate of extremity and chest imaging in a 5-year postoperative follow-up period for patients with extremity soft tissue sarcoma treated between 2007 and 2019. Imaging utilization was assessed according to patient demographics (age, sex, race and ethnicity, and region of residency), calendar year of surgery, and postoperative year. Associations of demographic variables with imaging use were assessed using chi-square tests, trends in imaging use were analyzed using the Cochran-Armitage trend test or linear regression, and associations of postoperative year with imaging use were evaluated with the Pearson Correlation coefficient. A total of 3707 patients were included. Most patients received at least 1 chest (74%) and extremity (53%) imaging examination during their follow-up period. The presence of surveillance imaging was significantly associated with age (P < 0.0001) and region (P = 0.0029). Over the study period, there was an increase in use of extremity MRI (P < 0.05) and ultrasound (P < 0.01) and chest CT (P < 0.0001) and a decrease in use of chest radiographs (P < 0.0001). Imaging use declined over postoperative years (decrease by 85%-92% from year 1-5). In conclusion, the use of surveillance imaging varied according to patient demographics and has increased for extremity MRI and ultrasound and chest CT over the study period.

Usefulness of MRI-Based Local Surveillance After Surgical Treatment of Musculoskeletal Soft-Tissue Sarcomas: A Systematic Review and Meta-Analysis.

BACKGROUND. The value of routine MRI follow-up after surgical treatment of musculoskeletal soft-tissue sarcoma (STS) is controversial. OBJECTIVE. The purpose of this study was to evaluate the usefulness of MRI-based surveillance for musculoskeletal STS represented by the proportion of local recurrences (LRs) discovered by MRI versus clinically, stratified by imaging surveillance intensity; the characteristics of LRs detected on imaging versus clinically; and the impact of imaging surveillance on survival. EVIDENCE ACQUISITION. Multiple electronic databases were searched systematically for articles published through November 28, 2022, about controlled trials and cohort studies on the usefulness of MRI-based surveillance for musculoskeletal STS. The risk of bias was assessed using an adapted Newcastle-Ottawa scale. Random-effects meta-analyses of the proportion of LRs discovered by MRI as opposed to clinically were conducted. The association of low- versus high-intensity surveillance with the proportion of LR detected on MRI was assessed with a chi-square test of subgroup differences; for this latter assessment, high intensity was defined as at least one local surveillance imaging examination for low-risk tumors and at least three imaging examinations for high-risk tumors during the first 2 posttreatment years. EVIDENCE SYNTHESIS. A total of 4821 titles and abstracts were identified, and 19 studies were included. All studies were retrospective cohorts. There was substantial variability in follow-up approaches. The risk of bias was moderate in 32% and high in 68% of studies. The pooled proportion of LRs detected on MRI was 53% (95% CI, 36-71%) with high-intensity surveillance and 6% (95% CI, 3-9%) with low-intensity surveillance (p < .01). Comparison of LR characteristics (LR size, depth, grade, location, resection margins) detected on imaging versus clinically identified inconsistent results between studies. Trends toward better survival for imaging-detected LRs or more frequent imaging use were noted in four studies. CONCLUSION. When used at a high intensity, MRI-based surveillance can detect many clinically occult LRs, although the studies are small, occasionally yielded conflicting results, and are often of poor quality. A survival benefit could be associated with imaging use, but further research is needed to evaluate the causality of any observed survival differences. CLINICAL IMPACT. MRI-based surveillance after surgical treatment of musculoskeletal STS is useful to detect clinically occult LRs and could improve patient outcomes.

The forgotten lacrimal gland and lacrimal drainage apparatus: pictorial review of CT and MRI findings and differential diagnosis.

The lacrimal gland is a bilobed serous gland located in the superolateral aspect of the orbit. Lacrimal system pathologies can be broadly divided into pathologies of the lacrimal gland and those of the nasolacrimal drainage apparatus. These include distinct congenital, infectious, inflammatory, and benign, indeterminate, and malignant neoplastic lesions. Trauma and resultant fractures affecting lacrimal drainage apparatus is not part of this review; only non-traumatic diseases will be discussed. CT is the initial modality of choice because of its ability to delineate lacrimal system anatomy and demonstrate most lacrimal drainage system abnormalities and their extent. It also assesses bony architecture and characterizes any osseous changes. MRI is helpful in further characterizing these lesions and better assessing involvement of the surrounding soft tissue structures. In this pictorial review, we will review the anatomy of the lacrimal system, describe CT/MRI findings of the common and uncommon lacrimal system abnormalities and discuss relevance of imaging with regards to patient management.

Incidence of infectious complications following ultrasound-guided percutaneous musculoskeletal interventions with the use of an uncovered transducer footprint.

OBJECTIVES: To determine the incidence of infectious complications following ultrasound-guided musculoskeletal interventions performed with a disinfected uncovered ultrasound transducer footprint. METHODS: Electronic medical records of all patients who underwent an ultrasound-guided musculoskeletal procedure (including injection, calcific lavage, or ganglion cyst aspiration) performed by any of the 14 interventional musculoskeletal radiologists at our institution between January 2013 and December 2018 were retrospectively reviewed to identify procedure site infections. Biopsies and joint aspirations were excluded. The procedures were performed using a disinfected uncovered transducer footprint. First, an automated chart review identified cases with (1) positive answers to the nurse's post-procedure call, (2) an International Classification of Diseases (ICD) diagnostic code related to a musculoskeletal infection, or (3) an antibiotic prescription within 30 days post-procedure. Then, these cases were manually reviewed for evidence of procedure site infection. RESULTS: In total, 6511 procedures were included. The automated chart review identified 3 procedures (2 patients) in which post-procedural fever was reported during the nurse's post-procedure call, 33 procedures (28 patients) with an ICD code for a musculoskeletal infection, and 220 procedures (216 patients) with an antibiotic prescription within 30 post-procedural days. The manual chart review of these patients revealed no cases of confirmed infection and 1 case (0.015%) of possible site infection. CONCLUSIONS: The incidence of infectious complications after an ultrasound-guided musculoskeletal procedure performed with an uncovered transducer footprint is extremely low. This information allows radiologists to counsel their patients more precisely when obtaining informed consent. KEY POINTS: • Infectious complications after ultrasound-guided musculoskeletal procedures performed with a disinfected uncovered transducer footprint are extremely rare.

Spotty Bone Marrow: A Frequent MRI Finding in the Feet of Ballet Dancers.

INTRODUCTION: Bone marrow signal abnormalities on magnetic resonance imaging (MRI) are common in athletes. However, few studies evaluate the MRI appearance of bone marrow in the feet of ballet dancers. Our study aims to describe the "spotty bone marrow" (SBM) pattern in the tarsal bones of a cohort of ballet dancers, establishing its prevalence, distribution, potential associations, and evolution.
Methods: Eighty-six MRIs of 68 ankles in 56 ballet dancers were retrospectively reviewed for mar- row signal alterations, which were classified as focal or SBM (defined as patchy fluid-sensitive signal hyperintensity spanning more than one location or tarsal bone). When SBM involved the talus, its anatomic distribution in the bone and morphologic pattern were recorded. Additional osseous and soft tissue findings were documented. For subjects with more than one MRI of the same ankle, the SBM's evolution was monitored.
Results: Spotty bone marrow was identified in 44 ankles (65%). Spotty bone marrow was isolated to the talus (44%), present in all tarsal bones (25%), or distributed between the talus and one to three other tarsal bones (31%). In the talus, The SBM involved the entire bone (65%), the neck and body (31%), or the head and neck (4%). The SBM most commonly showed a random morphologic pattern (87%) but occasionally showed a peripheral predominance (13%). There was no statistically significant difference in the prevalence of other pathologies in ankles with and without SBM. In eight ankles with a follow-up MRI, the SBM worsened in one, remained stable in two, and improved in five ankles. None progressed to a stress fracture.
Conclusion: Spotty bone marrow is an MRI finding frequently encountered in ballet dancers. It is usually self-limiting and should not be misinterpreted as a more aggressive pathology.

Applications of Artificial Intelligence in Musculoskeletal Imaging: From the Request to the Report.

Artificial intelligence (AI) will transform every step in the imaging value chain, including interpretive and noninterpretive components. Radiologists should familiarize themselves with AI developments to become leaders in their clinical implementation. This article explores the impact of AI through the entire imaging cycle of musculoskeletal radiology, from the placement of the requisition to the generation of the report, with an added Canadian perspective. Noninterpretive tasks which may be assisted by AI include the ordering of appropriate imaging tests, automatic exam protocoling, optimized scheduling, shorter magnetic resonance imaging acquisition time, computed tomography imaging with reduced artifact and radiation dose, and new methods of generation and utilization of radiology reports. Applications of AI for image interpretation consist of the determination of bone age, body composition measurements, screening for osteoporosis, identification of fractures, evaluation of segmental spine pathology, detection and temporal monitoring of osseous metastases, diagnosis of primary bone and soft tissue tumors, and grading of osteoarthritis.

Human T cell lymphotropic virus type-1 associated lymphoma presenting as an intramuscular mass of the calf.

Adult T cell leukemia/lymphoma (ATLL) is a mature T cell neoplasm caused by the human oncogenic retrovirus human T lymphotropic virus type-1 (HTLV-1). While several musculoskeletal manifestations have been described in ATLL, skeletal muscle involvement is unusual, with only four cases reported in the English-language literature. We present a rare case of ATLL manifesting as an intra-muscular calf mass in a 58-year-old man who immigrated to the USA from West Africa. While skeletal muscle involvement by lymphoma is uncommon, it remains important to consider within the differential diagnosis when there are suggestive imaging findings because it entails important technical biopsy considerations as well as treatment implications. This case report also raises awareness of ATLL presenting outside of typical HTLV-1 endemic areas, related to current population migration patterns. ATLL should therefore be considered in patients with appropriate risk factors.

Pattern Recognition in Musculoskeletal Imaging Using Artificial Intelligence.

Artificial intelligence (AI) has the potential to affect every step of the radiology workflow, but the AI application that has received the most press in recent years is image interpretation, with numerous articles describing how AI can help detect and characterize abnormalities as well as monitor disease response. Many AI-based image interpretation tasks for musculoskeletal (MSK) pathologies have been studied, including the diagnosis of bone tumors, detection of osseous metastases, assessment of bone age, identification of fractures, and detection and grading of osteoarthritis. This article explores the applications of AI for image interpretation of MSK pathologies.

Early detection of metastases using whole-body MRI for initial staging and routine follow-up of myxoid liposarcoma.

OBJECTIVE: To define the role of whole-body MRI (WBMRI) for initial staging and routine follow-up of myxoid liposarcoma (MLS). MATERIALS AND METHODS: A retrospective review of all the patients with MLS who underwent WBMRI for initial staging and routine follow-up at our institution between October 1, 2006, and September 30, 2016 was performed. Patient demographics, clinical presentation, imaging findings, tumor histology, and occurrence and location of metastatic disease were recorded. Thirty-three patients who underwent a total of 150 WBMRI examinations were included in the study. RESULTS: Nine patients (27%) were diagnosed with metastases between 0 and 60 months (median 10; interquartile range, 7-13) from the diagnosis of the primary tumor. The initial site of metastatic disease was extrapulmonary in all patients. Only two patients developed pulmonary metastases, which were diagnosed by CT chest 9 and 29 months after the diagnosis of extrapulmonary metastases. The first metastasis was diagnosed by WBMRI in seven patients (78%), by thoracic CT in one patient, and by abdominal CT in one patient. Eight of nine patients (89%) were asymptomatic at the time of diagnosis of the metastases. In seven patients (78%), WBMRI demonstrated metastases included within the field of view of, but occult on a contemporaneous CT scan. CONCLUSION: Our 10-year institutional experience demonstrates that WBMRI facilitates early detection of extrapulmonary MLS metastases before the onset of clinical symptoms and pulmonary metastases. WBMRI also depicts extrapulmonary metastases that are occult on CT scans. The current surveillance strategies are insufficient for screening for extrapulmonary MLS metastases.

Intraventricular hemorrhage in term neonates with hypoxic-ischemic encephalopathy: a comparison study between neonates treated with and without hypothermia.

BACKGROUND: To retrospectively determine the prevalence of intraventricular hemorrhage (IVH) in term neonates with hypoxic-ischemic encephalopathy (HIE) using head ultrasound (HUS) and MRI, and to compare the incidence of IVH in term babies with HIE treated by therapeutic hypothermia versus those managed conventionally. METHODS: A total of 61 term neonates from two institutions were diagnosed with HIE shortly after birth. Thirty infants from one institution were treated with whole body hypothermia. These infants had to satisfy the entry criteria for the neonatal hypothermia protocol of the institution. Thirty-one neonates underwent conventional treatment at the second institution. At that time, hypothermia was not yet a standard of care at that institution. All the neonates underwent HUS in their first 23 days of life. The 54 survivors also underwent MRI. The imaging studies were all reviewed for IVH. RESULTS: Amongst the 30 babies, who received whole body hypothermia, there were 18 males and 12 females, the mean birth weight was 3.5 kg (2.5 to 5.2 kg), and the HUS study was performed within 14.8 to 41 hours of life. The group of 31 infants treated conventionally was comprised of 12 boys and 19 girls, the infants had an average birth weight of 3.3 kg (2.3 to 4.2 kg), and they underwent HUS 1 to 23 days after birth, with only five children being older than 1 week at the time of the imaging studies. Four of the 61 infants (7%) were diagnosed with IVH on HUS. Three were confirmed with MRI. The fourth case showed a bilateral enlarged choroid plexus on HUS, but IVH could not be confirmed with MRI, as the infant did not survive. In the group of neonates treated with hypothermia, there were three cases (10%) of IVH, whereas in the group managed conventionally, IVH occurred in one infant (3%). CONCLUSIONS: Our study shows that IVH remains uncommon in term infants with HIE. IVH was more prevalent in the group treated with hypothermia.

Ewing's sarcoma of the patella.

Ewing's sarcoma is a relatively rare malignancy, occurring mainly between 4 and 25 years of age. It usually arises from the pelvis, followed by the femur, tibia, and remainder of both the long bones of the extremities and flat bones of the axial skeleton. To the best of our knowledge, Ewing's sarcoma of the patella has never been reported previously. Patellar tumors occur infrequently and represent an uncommon etiology of anterior knee pain. We describe the rare case of a 41-year-old man who presented with a 3-4 month history of escalating right anterior knee pain and swelling. Imaging demonstrated an aggressive patellar tumor with an adjacent soft tissue mass. The diagnosis of Ewing's sarcoma was confirmed by pathology. Physicians should be aware of atypical locations for Ewing's sarcoma and, conversely, of rare tumors arising in the patella and accounting for anterior knee pain. Early recognition of such malignancies allows prompt initiation of treatment, hence improving prognosis.