Faculty Bibliography

BACKGROUND:Bone stress injuries (BSIs) occur in up to 20% of runners and military personnel. Typically, after a period of unloading and gradual return to weightbearing activities, athletes return to unrestricted sports participation or military duty approximately 4 to 14 weeks after a BSI diagnosis, depending on the injury location and severity. However, the time course of the recovery of the bone's mechanical competence is not well-characterized, and reinjury rates are high. PURPOSE:To assess the bone microarchitecture and volumetric bone mineral density (vBMD) over 12 months after a tibial BSI diagnosis. STUDY DESIGN:Case-control study; Level of evidence, 3. METHODS:We enrolled 30 female athletes from the local community (aged 18-35 years) with a tibial BSI (grade ≥2 of 4 on magnetic resonance imaging) for this prospective observational study. Participants completed a baseline visit within 3 weeks of the diagnosis. At baseline and 6, 12, 24, and 52 weeks after the BSI diagnosis, we collected high-resolution peripheral quantitative computed tomography scans of the ultradistal tibia (4% of tibial length) of the injured and uninjured legs as well as pain and physical activity assessment findings. RESULTS:< .05 for all). CONCLUSION:Bone density declined in both the injured and the uninjured legs and, on average, did not return to baseline for 3 to 6 months after a tibial BSI diagnosis. The observed time to the recovery of baseline vBMD, coupled with the high rate of recurrent BSIs, suggests that improved return-to-sports and military duty guidelines may be in order.

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/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/CONCLUSIONS: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.

Aneurysmal bone cyst is a benign bone neoplasm that most commonly arises from the metaphyses of long bones in the first and second decades of life. Here, we describe a case of an aneurysmal bone cyst that occurred in the distal tibial diaphysis of a 72-year-old female that was concerning for malignancy on imaging, demonstrating cortical breakthrough and soft tissue extension. Histologically, the tumor showed the characteristic morphologic features of aneurysmal bone cyst. Fluorescence in situ hybridization was positive for USP6 rearrangement, and RNA sequencing revealed a USP6 gene fusion with VDR, a novel partner that encodes the vitamin D receptor and that has not been implicated previously in human neoplasia. This case highlights the diagnostic challenges presented by aneurysmal bone cyst in elderly adults, and it expands the genetic spectrum of USP6 rearrangements.

All components of the musculoskeletal system can be involved by metabolic disorders as a result of endocrine diseases, genetic alterations, and environmental or nutritional aspects, with important worldwide variations in prevalence and severity. Early detection of these disorders is crucial because of the efficacy of preventive measures and availability of treatments. The current chapter will focus on the imaging appearance of metabolic disorders of bone marrow and of the mineralized skeleton. Marrow and bone disorders in athletes, the elderly, and individuals with eating disorders will be reviewed.

BACKGROUND/OBJECTIVE:Obesity is a strong risk factor for adverse outcomes in patients hospitalized with COVID-19, however, the distribution of fat and the amount of muscle mass are more accurate risk factors than BMI. The objective of this study was to assess body composition measures obtained on opportunistic abdominal CTs as predictors of outcome in patients hospitalized with COVID-19. We hypothesized that elevated visceral and intermuscular adipose tissue would be associated with adverse outcome. SUBJECTS/METHODS:Our retrospective study was IRB-approved and HIPAA-compliant. The study group comprised 124 patients (median age: 68 years, IQR: 56, 77; 59 weeks, 65 months) who were admitted with COVID-19 to a single hospital and who had undergone abdominal CT for clinical purposes. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), intermuscular adipose tissue (IMAT), and paraspinal and abdominal muscle cross-sectional areas (CSA) were assessed. Clinical information including prognostic factors, time of admission to the intensive care unit (ICU) and time of death within 28 days were obtained. Multivariate time-to-event competing risk models were fitted to estimate the hazard ratio (HR) for a composite outcome of ICU admission/mortality associated with a one standard deviation increase in each body compositional measure. Each model was adjusted for age, sex, race, BMI, and cardiometabolic comorbidities. RESULTS:There were 50 patients who were admitted to the ICU or deceased over a median time of 1 day [IQR 1, 6] from hospital admission. Higher VAT/SAT ratio (HR of 1.30; 95% CI 1.04-1.62, p = 0.022) and higher IMAT CSA (HR of 1.44; 95% CI 1.10-1.89, p = 0.008) were associated with a reduced time to ICU admission or death in adjusted models. CONCLUSION:VAT/SAT and IMAT are predictors of adverse outcome in patients hospitalized with COVID-19, independent of other established prognostic factors. This suggests that body composition measures may serve as novel biomarkers of outcome in patients with COVID-19.

Research examining bone marrow adipose tissue (BMAT) has rapidly expanded during the last two decades, leading to advances in knowledge on the role of BMAT in the pathogenesis of bone loss and endocrine disorders. Clinical imaging has played a crucial role for the in vivo assessment of BMAT, allowing non-invasive quantification and evaluation of BMAT composition. In the present work, we review different imaging methods for assessing properties of BMAT. Our aim is to review conventional magnetic resonance imaging (MRI), water-fat imaging, and single-voxel proton magnetic resonance spectroscopy (¹H-MRS), as well as computed tomography (CT)-based techniques, including single energy and dual energy CT. We will also discuss the clinical applications of these methods in type 2 diabetes mellitus, obesity and anorexia nervosa.

BACKGROUND:Bone marrow adipose tissue (BMAT) plays a role in systemic energy metabolism and responds to nutritional changes. Chronic starvation as well as visceral adiposity are associated with BMAT accumulation. Two types of BMAT have been described which differ in anatomic location (proximal-regulated-rBMAT vs distal-constitutive-cBMAT) and composition (higher unsaturated lipids of cBMAT compared to rBMAT). OBJECTIVE:To determine the response of BMAT composition to short-term high-caloric feeding and fasting. We hypothesized that high-feeding and caloric restriction would be associated with differences in BMAT composition according to the skeletal site. MATERIALS AND METHODS:) who were admitted for a 10-day high-caloric stay (caloric intake with goal to achieve 7% weight gain) followed by discharge home for 13-18 days to resume normal diet (stabilization period), followed by a 10-day fasting stay (no caloric intake). Subjects underwent single voxel proton MR spectroscopy (1H-MRS) at 3T of the lumbar spine (L4) (rBMAT), the femoral diaphysis and distal tibial metaphysis (cBMAT) to determine BMAT composition (unsaturation index, UI and saturation index, SI). Within group comparisons were performed by the Wilcoxon signed rank test. RESULTS:After the high-calorie visit, SI of L4 increased compared to baseline (0.62 ± 0.27 to 0.70 ± 0.28, p = 0.02), and there was a trend of an increase in femoral SI and UI (p ≥ 0.07), while there was no significant change in tibial BMAT (p ≥ 0.13). During the stabilization period, SI of L4 decreased (0.70 ± 0.28 to 0.57 ± 0.21, p < 0.0001) and SI of the femoral diaphysis decreased (5.37 ± 2.27 to 5.09 ± 2.43, p = 0.03), while there was no significant change in UI or tibial BMAT (p ≥ 0.14). During the fasting period, SI of L4 increased (0.57 ± 0.21 to 0.63 ± 0.30, p = 0.03), while there was no change in UI (p = 0.7). SI and UI of femoral diaphysis decreased (5.09 ± 2.43 to 4.68 ± 2.15, p = 0.03, and 0.62 ± 0.42 to 0.47 ± 0.37, p = 0.02, respectively) and UI of the tibial metaphysis decreased (1.48 ± 0.49 to 1.24 ± 0.57, p = 0.04). CONCLUSION:1H-MRS is able to quantify BMAT composition during short-term nutritional challenges, showing a significant increase in SI of rBMAT during high caloric feeding and a differential response to fasting with an increase in SI of rBMAT and a decrease in SI and UI of femoral cBMAT and decrease in UI of tibial cBMAT.

PURPOSE/OBJECTIVE:To compare the pathology results of CT-guided and blind bone marrow aspirations and biopsies. METHODS:Ninety-eight consecutive CT-guided biopsies and 98 age- and gender-matched blind (non-CT-guided) posterior iliac crest bone marrow aspirations and biopsies performed in 2017 were reviewed for adequacy of core biopsies and aspirate smears. CT procedure images and CT abdomen/pelvis images were reviewed to evaluate anatomic features of the posterior ilium and soft tissues. Statistical analysis was performed using a T test, Fisher exact test, and Kruskal-Wallis test. RESULTS:There was no significant difference in the age and gender of the two groups (p > 0.05). However, the CT-guided group had a higher BMI (p = 0.0049) and posterior soft tissue thickness (p = 0.0016). More CT-guided biopsy samples (CT 93 (95%); blind 77 (79%); p = 0.0006) and aspirate smears (CT 90 (92%); blind 78 (80%); p = 0.042) were categorized as adequate. The CT-guided group had longer core lengths (CT 1.4 ± 0.6 (range 0.3-3.5) cm; blind 1.0 ± 0.60 (range 0-2.6) cm; p = 0.0001). Overall, 131/164 (80%) of the cases had at least one of the described features (slanted posterior ilium (angle > 30°), 30%; rounded posterior ilium, 20%; thick posterior ilium cortex, 13%; focal lesion in posterior ilium, 12%; prior procedure in posterior ilium, 5%; posterior soft tissue thickness > 3 cm, 40%). CONCLUSION/CONCLUSIONS:CT-guided bone marrow procedures were more likely to result in both adequate aspirate smears and biopsy samples and longer core lengths when compared with blind procedures.

OBJECTIVE:The aim of the study was to determine abdominal and breast adipose tissue parameters on 18-fluorodeoxyglucose positron emission tomography/computed tomography (CT) that may serve as outcome predictors in breast angiosarcoma patients. MATERIALS/METHODS:Women with breast angiosarcoma (n = 13) who underwent 18-fluorodeoxyglucose positron emission tomography/CT were identified. A control group was selected (n = 25). Abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) were assessed on unenhanced computed tomographies. Breast adipose tissue (BAT) volumes of the uninvolved breast were quantified. Metabolic activity of VAT, SAT, and BAT was calculated (standardized uptake value [SUV]). RESULTS:Breast angiosarcoma patients had higher metabolic activity of VAT compared with controls (SUV 0.93 ± 0.39 vs 0.64 ± 0.11, P = 0.044). Within the patient group, there were 6 deaths (46.2%). Patients who died had higher SAT activity (SUV 0.52 ± 0.24 vs 0.29 ± 0.06, P = 0.027) and higher BAT metabolic activity (SUV 0.48 ± 0.20 vs 0.27 ± 0.11, P = 0.045) compared with nondeceased patients. CONCLUSIONS:Patients with breast angiosarcoma have higher metabolic activity of VAT. Higher abdominal SAT and higher BAT metabolic activity of the uninvolved breast might predict mortality.