Pre-treatment [18F]FDG PET/CT for assessing bone marrow involvement and prognosis in patients with newly diagnosed peripheral T-cell lymphoma

PURPOSE

To explore the value of [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in assessing bone marrow involvement (BMI) and prognosis in newly diagnosed peripheral T-cell lymphomas (PTCLs) before treatment.

METHODS

This retrospective study included 201 eligible PTCLs who received pre-bone marrow biopsy (BMB) and PET/CT. The status of bone marrow (BM) by PET was assessed using a visual examination and a quantitative index (the maximal standardized uptake value [SUVmax] of BM divided by the SUVmax of the liver [M/L]).

RESULTS

Totally 148 patients had no evidence of BMI by PET or BMB; BMI was detected by both methods in 16 patients. The sensitivity and specificity of PET/CT for patients with confirmed BMI by BMB were 43.2% and 90.2%, respectively (κ =  0.353). In addition, 25 patients assessed by PET/CT staging (having stage I to II disease) had no evidence of BMI detected by both PET/CT and BMB. Image-guided biopsy was also recommended when PET/CT showed a focal FDG uptake outside the iliac crest. Survival analysis revealed that BMB was significant for overall survival (OS) (P = 0.020) while M/L for both progression free survival (P = 0.002) and OS (P < 0.001). In multivariate analysis, M/L (HR 1.825, 95% CI 1.071-3.110, P = 0.027) was an independent prognostic factor for OS. There were no statistical differences at the genetic level about BMI confirmed by PET or BMB.

CONCLUSION

PET/CT has a complementary role in assessing BMI and an ability to predict prognosis in PTCL patients.

Multiparametric quantification of T1 and T2 relaxation time of bone metastasis in comparison with red or fatty bone marrow using magnetic resonance fingerprinting

OBJECTIVES

To assess the T1 and T2 values of bone marrow lesions in spine and pelvis derived from magnetic resonance fingerprinting (MRF) and to evaluate the differences in values among bone metastasis, red marrow and fatty marrow.

METHODS

Sixty patients who underwent lumbar spine and pelvic MRI with magnetic resonance fingerprinting were retrospectively included. Among eligible patients, those with bone metastasis, benign red marrow deposition and normal fatty marrow were identified. Two radiologists independently measured the T1 and T2 values from metastatic bone lesions, fatty marrow, and red marrow deposition on three-dimensional-magnetic resonance fingerprinting. Intergroup comparison and interobserver agreement were analyzed.

RESULTS

T1 relaxation time was significantly higher in osteoblastic metastasis than in red marrow (1674.6 ± 436.3 vs 858.7 ± 319.5, p < .001). Intraclass correlation coefficients for T1 and T2 values were 0.96 (p < 0.001) and 0.83 (p < 0.001), respectively. T2 relaxation time of osteoblastic metastasis and red marrow deposition had no evidence of a difference (osteoblastic metastasis, 57.9 ± 25.0 vs red marrow, 58.0 ± 34.4, p = 0.45), as were the average T2 values of osteolytic metastasis and red marrow deposition (osteolytic metastasis, 45.3 ± 15.1 vs red marrow, 58.0 ± 34.4, p = 0.63).

CONCLUSIONS

We report the feasibility of three-dimensional-magnetic resonance fingerprinting based quantification of bone marrow to differentiate bone metastasis from red marrow. Simultaneous T1 and T2 quantification of metastasis and red marrow deposition was possible in spine and pelvis and showed significant different values with excellent inter-reader agreement.

ADVANCE IN KNOWLEDGE

T1 values from three-dimensional-magnetic resonance fingerprinting might be a useful quantifier for evaluating bone marrow lesions.

Quantitative MRI reveals heterogeneous impacts of treatment on diseased bone marrow in a mouse model of myelofibrosis

PURPOSE

Analyzing bone marrow in the hematologic cancer myelofibrosis requires endpoint histology in mouse models and bone marrow biopsies in patients. These methods hinder the ability to monitor therapy over time. Preclinical studies typically begin treatment before mice develop myelofibrosis, unlike patients who begin therapy only after onset of disease. Using clinically relevant, quantitative MRI metrics allowed us to evaluate treatment in mice with established myelofibrosis.

METHODS

We used chemical shift-encoded fat imaging, DWI, and magnetization transfer sequences to quantify bone marrow fat, cellularity, and macromolecular components in a mouse model of myelofibrosis. We monitored spleen volume, the established imaging marker for treatment, with anatomic MRI. After confirming bone marrow disease by MRI, we randomized mice to treatment with an approved drug (ruxolitinib or fedratinib) or an investigational agent, navitoclax, for 33 days. We measured the effects of therapy over time with bone marrow and spleen MRI.

RESULTS

All treatments produced heterogeneous responses with improvements in bone marrow evident in subsets of individual mice in all treatment groups. Reductions in spleen volume commonly occurred without corresponding improvement in bone marrow. MRI revealed patterns associated with effective and ineffective responses to treatment in bone marrow and identified regional variations in efficacy within a bone.

CONCLUSIONS

Quantitative MRI revealed modest, heterogeneous improvements in bone marrow disease when treating mice with established myelofibrosis. These results emphasize the value of bone marrow MRI to assess treatment in preclinical models and the potential to advance clinical trials for patients.

Evaluation of bone marrow invasion on the machine learning of 18 F-FDG PET texture analysis in lower gingival squamous cell carcinoma

OBJECTIVES

Lower gingival squamous cell carcinoma (LGSCC) has the potential to invade the alveolar bone. Traditionally, the diagnosis of LGSCC relied on morphological imaging, but inconsistencies between these assessments and surgical findings have been observed. This study aimed to assess the correlation between LGSCC bone marrow invasion and PET texture features and to enhance diagnostic accuracy by using machine learning.

METHODS

A retrospective analysis of 159 LGSCC patients with pretreatment 18 F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) examination from 2009 to 2017 was performed. We extracted radiomic features from the PET images, focusing on pathologic bone marrow invasion detection. Extracted features underwent the least absolute shrinkage and selection operator algorithm-based selection and were then used for machine learning via the XGBoost package to distinguish bone marrow invasion presence. Receiver operating characteristic curve analysis was performed.

RESULTS

From the 159 patients, 88 qualified for further analysis (59 men; average age, 69.2 years), and pathologic bone marrow invasion was identified in 69 (78%) of these patients. Three significant radiological features were identified: Gray level co-occurrence matrix_Correlation, INTENSITY-BASED_IntensityInterquartileRange, and MORPHOLOGICAL_SurfaceToVolumeRatio. An XGBoost machine-learning model, using PET radiomic features to detect bone marrow invasion, yielded an area under the curve value of 0.83.

CONCLUSION

Our findings highlighted the potential of 18 F-FDG PET radiomic features, combined with machine learning, as a promising avenue for improving LGSCC diagnosis and treatment. Using 18 F-FDG PET texture features may provide a robust and accurate method for determining the presence or absence of bone marrow invasion in LGSCC patients.

Demonstration of magnetic resonance Z-spectral imaging for fatty acid characterization of bone marrow at 3 T

Magnetic resonance Z-spectral imaging (ZSI) has emerged as a new approach to measure fat fraction (FF). However, its feasibility for fat spectral imaging remains to be elucidated. In this study, a single-slice ZSI sequence dedicated to fat spectral imaging was designed, and its capability for fatty acid characterization was investigated on peanut oil samples, a multiple-vial fat-water phantom with varied oil volumes, and vertebral body marrow in healthy volunteers and osteoporosis patients at 3 T. The peanut oil spectrum was also recorded with a 400-MHz NMR spectrometer. A Gaussian-Lorentzian sum model was used to resolve water and six fat signals of the pure oil sample or four fat signals of the fat-water phantom or vertebral bone marrow from Z spectra. Fat peak amplitudes were normalized to the total peak amplitude of water and all fat signals. Normalized fat peak amplitudes and FF were quantified and compared among vials of the fat-water phantom or between healthy volunteers and osteoporosis patients. An unpaired student's t-test and Pearson's correlation were conducted, with p less than 0.05 considered statistically significant. The results showed that the peanut oil spectra measured with the ZSI technique were in line with respective NMR spectra, with amplitudes of the six fat signal peaks significantly correlated between the two methods (y = x + 0.001, r = 0.996, p < 0.001 under a repetition time of 1.6 s; and y = 1.026x - 0.003, r = 0.996, p < 0.001 under a repetition time of 3.1 s). Moreover, ZSI-measured FF exhibited a significant correlation with prepared oil volumes (y = 0.876x + 1.290, r = 0.996, p < 0.001). The osteoporosis patients showed significantly higher normalized fat peak amplitudes and FF in the L4 vertebral body marrow than the healthy volunteers (all p < 0.01). In summary, the designed ZSI sequence is feasible for fatty acid characterization, and has the potential to facilitate the diagnosis and evaluation of diseases associated with fat alterations at 3 T.

Recurrent Marginal Zone Lymphoma with Bone Marrow Involvement Detected by ¹⁸F-FDG PET/CT and Biopsy: A Diagnostic Challenge

BACKGROUND Marginal zone lymphoma is a low-grade, B-cell, non-Hodgkin lymphoma. Bone marrow involvement (BMI) of leukemia or lymphoma can usually be displayed in fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) with high standardized uptake values (SUV), while diffuse homogeneous ¹⁸F-FDG bone marrow uptake (BMU) in PET/CT primarily reflects hyperplastic bone marrow status. This report is of a 74-year-old man presenting with anemia and a diagnosis of recurrent marginal zone lymphoma with bone marrow involvement identified with 18F-FDG PET/CT imaging and biopsy. CASE REPORT A 64-year-old man with severe anemia and body weight loss of 7 kg in 1 month was diagnosed with marginal zone lymphoma, stage III, in July 2011. He went into complete remission in April 2012 after 6 cycles of chemotherapy, with Hb restored. Anemia and diffuse homogeneous ¹⁸F-FDG BMU in PET/CT were then noted during a routine check-up in October 2021, and recurrent disease was established through positive biopsy of subcutaneous nodules and bone marrow. Subsequent complete remission after 6 cycles of combination therapy was validated with pathologically negative BMI, the resolution of the slightly enhanced ¹⁸F-FDG BMU in PET/CT, and restored hemoglobin. CONCLUSIONS This report has highlighted the importance of follow-up for patients with lymphoma and supports the diagnostic role of ¹⁸F-FDG PET/CT imaging and the pathological verification in identifying malignant involvement in bone marrow.

Chemical shift-encoded MRI with compressed sensing combined with parallel imaging for proton density fat fraction measurement of the lumbar vertebral bone marrow

We aimed to investigate the accuracy of proton density fat fraction (PDFF) measurement of the lumbar vertebral bone marrow using chemical shift-encoded magnetic resonance imaging (CSE-MRI) with compressed sensing combined with parallel imaging (CSPI). This study recruited a commercially available phantom, and 43 patients. Fully sampled data without CSPI and under-sampled data with CSPI acceleration factors of 2.4, 3.6, and 4.8 were acquired using a 1.5T imaging system. The relationships between PDFF measurements obtained with the no-CSPI acquisition and those obtained with each CSPI acquisition were assessed using Pearson correlation coefficient (r), linear regression analyses, and Bland-Altman analysis. The intra- and inter-observer variabilities of the PDFF measurements were evaluated using the intraclass correlation coefficient. PDFF measurements obtained with all acquisitions showed a significant correlation and strong agreement with the reference PDFF measurement of the phantom. PDFF measurements obtained using CSE-MRI with and without CSPI were positively correlated (all acquisitions: r = 0.99; P < .001). The mean bias was -0.31% to -0.17% with 95% limits of agreement within ±2.02%. The intra- and inter-observer agreements were excellent (intraclass correlation coefficient: 0.988 and 0.981, respectively). A strong agreement and positive correlation were observed between the PDFF measurements obtained using CSE-MRI with and without CSPI. PDFF measurement of the lumbar vertebral bone marrow using CSE-MRI with CSPI can be acquired with a maximum reduction of approximately 75% in the acquisition time compared with a fully sampled acquisition.

Longitudinal MR-based proton-density fat fraction (PDFF) and T2* for the assessment of associations between bone marrow changes and myelotoxic chemotherapy

OBJECTIVES

MR imaging-based proton density fat fraction (PDFF) and T2* imaging has shown to be useful for the evaluation of degenerative changes in the spine. Therefore, the aim of this study was to investigate the influence of myelotoxic chemotherapy on the PDFF and T2* of the thoracolumbar spine in comparison to changes in bone mineral density (BMD).

METHODS

In this study, 19 patients were included who had received myelotoxic chemotherapy (MC) and had received a MR imaging scan of the thoracolumbar vertebrates before and after the MC. Every patient was matched for age, sex, and time between the MRI scans to two controls without MC. All patients underwent 3-T MR imaging including the thoracolumbar spine comprising chemical shift encoding-based water-fat imaging to extract PDFF and T2* maps. Moreover, trabecular BMD values were determined before and after chemotherapy. Longitudinal changes in PDFF and T2* were evaluated and compared to changes in BMD.

RESULTS

Absolute mean differences of PDFF values between scans before and after MC were at 8.7% (p = 0.01) and at -0.5% (p = 0.57) in the control group, resulting in significantly higher changes in PDFF in patients with MC (p = 0.008). BMD and T2* values neither showed significant changes in patients with nor in those without myelotoxic chemotherapy (p = 0.15 and p = 0.47). There was an inverse, yet non-significant correlation between changes in PDFF and BMD found in patients with myelotoxic chemotherapy (r = -0.41, p = 0.12).

CONCLUSION

Therefore, PDFF could be a useful non-invasive biomarker in order to detect changes in the bone marrow in patients receiving myelotoxic therapy.

CLINICAL RELEVANCE STATEMENT

Using PDFF as a non-invasive biomarker for early bone marrow changes in oncologic patients undergoing myelotoxic treatment may help enable more targeted countermeasures at commencing states of bone marrow degradation and reduce risks of possible fragility fractures.

KEY POINTS

Quantifying changes in bone marrow fat fraction, as well as T2* caused by myelotoxic pharmaceuticals using proton density fat fraction, is feasible. Proton density fat fraction could potentially be established as a non-invasive biomarker for early bone marrow changes in oncologic patients undergoing myelotoxic treatment.

Assessment of Bone Marrow Involvement in Extranodal NK/T-Cell Lymphoma: Positron Emission Tomography versus Bone Marrow Biopsy, and the Significance of Minimal Involvement by EBV+ Cells (KROG 18-09)

PURPOSE

This study aims to investigate the diagnostic significance of positron emission tomography/computed tomography (PET/CT) in assessing bone marrow (BM) involvement through a comparison of PET/CT findings with BM biopsy in extranodal natural killer/T-cell lymphoma.

MATERIALS AND METHODS

The medical records of 193 patients were retrospectively reviewed. Patients were categorized as having early-stage (PET-ES) or advanced-stage (PET-AS) disease based on PET/CT results. The BM involvement was classified into three groups according to BM biopsy: gross BM involvement, minimal BM involvement (defined as the presence of a limited number of Epstein-Barr virus-positive cells in BM), and no involvement. Calculations of the accuracy of PET/CT in detecting BM involvement and analysis of the clinical outcomes (progression-free survival [PFS] and overall survival [OS]) according to the BM biopsy status were performed.

RESULTS

PET/CT exhibited a sensitivity of 64.7% and a specificity of 96.0% in detecting gross BM involvement. For detecting any (both gross and minimal) BM involvement, the sensitivity was 30.4%, while the specificity was 99.0%. Only one patient (0.7%) demonstrated gross BM involvement among the PET-ES group. Survival outcomes of the PET-ES group with minimal BM involvement (3-year PFS, 55.6%; OS, 77.0%) were closer to those of the PET-ES group with no BM involvement (3-year PFS, 62.2%; OS, 80.6%) than to those of the PET-AS group (3-year PFS, 20.1%; OS, 29.9%).

CONCLUSION

PET/CT exhibits high specificity, but moderate and low sensitivity in detecting gross and minimal BM involvement, respectively. The clinical significance of minimal BM involvement for patients in the PET-ES group may be limited.

The quantitative parameters based on marrow metabolism derived from synthetic MRI: A pilot study of prognostic value in participants with newly diagnosed multiple myeloma

BACKGROUND

The value of SyMRI-derived parameters from lumbar marrow for predicting early treatment response and optimizing the risk stratification of the Revised International Staging System (R-ISS) in participants with multiple myeloma (MM) is unknown.

METHODS

We prospectively enrolled participants with newly diagnosed MM before treatment. The SyMRI of lumbar marrow was used to calculate T1, T2, and PD values and the clinical features were collected. All participants were divided into good response (≥VGPR) and poor response (

RESULTS

Fifty-nine participants (good response, n = 33; poor response, n = 26) were evaluated. The bone marrow plasma cell percentage, β2-microglobulin, T1 and T2 value were difference between two groups (all p < 0.05). The T1 (odds ratio 1.003, p = 0.005) and T2 values (odds ratio 0.910, p = 0.002) were independent predictors and the AUC and cut-off values were 0.787, 967.2 ms and 0.784, 75.9 ms, respectively. There were no significant differences in SyMRI parameters between genders. Participants with both T1 value ≥967.2 ms and T2 value ≤75.9 ms in the R-ISS II stage were potentially to get poor response.

CONCLUSIONS

Synthetic MRI is a promising tool for predicting early treatment response to MM and promoting R-ISS II stage risk stratification.

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Key Words

• R‐ISS stage
• early treatment response
• magnetic resonance imaging
• multiple myeloma
• tumor burden

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MESH Headings

• Humans
• Male
• Female
• Prognosis
• Multiple Myeloma/diagnostic imaging
• Multiple Myeloma/pathology
• Bone Marrow/diagnostic imaging
• Bone Marrow/pathology
• Pilot Projects
• Neoplasm Staging
• Magnetic Resonance Imaging
• Retrospective Studies

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Grants

• 82071898 National Natural Science Foundation of China
• National Natural Science Foundation of China

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Affiliation(s)

Sha Cui Department of Medical ImagingShanxi Medical UniversityTaiyuanChina Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina
Yinnan Guo Department of PainFifth Hospital of Shanxi Medical UniversityTaiyuanChina
Weiran Niu Department of Medical ImagingShanxi Medical UniversityTaiyuanChina
Jianting Li Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina
Wenjin Bian Department of Medical ImagingShanxi Medical UniversityTaiyuanChina
Wenqi Wu Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina
Wenjia Zhang Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina
Qian Zheng Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina
Jun Wang Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina
Jinliang Niu Department of RadiologySecond Hospital of Shanxi Medical UniversityTaiyuanChina

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The prognostic value of bone marrow retention index and bone marrow-to-liver ratio of baseline 18F-FDG PET/CT in diffuse large B-cell lymphoma

OBJECTIVE

To determine prognostic value of bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) measured on baseline dual-phase 18F-FDG PET/CT in a series of newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) treated homogeneously with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

PATIENTS AND METHODS

This prospective study enrolled 135 patients with newly diagnosed DLBCL. All patients underwent dual-phase 18F-FDG PET/CT. The following PET parameters were calculated for both tumor and bone marrow: maximum standardized uptake value (SUVmax) at both time points (SUVmax early and SUVmax delayed), SUVmax increment (SUVinc), RI, and BLR. Patients were treated with R-CHOP regimen and response at end of treatment was assessed.

RESULTS

The final analysis included 98 patients with complete remission. At a median follow-up of 22 months, 57 patients showed no relapse, 74 survived, and 24 died. The 2-year relapse-free survival (RFS) values for patients with higher and lower RI-bm were 20% and 65.1%, respectively (p < 0.001), and for patients with higher and lower BLR were 30.2% and 69.6%, respectively (p < 0.001). The 2-year overall survival (OS) values for patients with higher and lower RI-bm were 60% and 76.3%, respectively (p = 0.023), and for patients with higher and lower BLR were 57.3% and 78.6%, respectively (p = 0.035). Univariate analysis revealed that RI-bm and BLR were independent significant prognostic factors for both RFS and OS (hazard ratio [HR] = 4.02, p < 0.001, and HR = 3.23, p < 0.001, respectively) and (HR = 2.83, p = 0.030 and HR = 2.38, p = 0.041, respectively).

CONCLUSION

Baseline RI-bm and BLR were strong independent prognostic factors in DLBCL patients.

CLINICAL RELEVANCE STATEMENT

Bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) could represent suitable and noninvasive positron emission tomography/computed tomography (PET/CT) parameters for predicting pretreatment risk in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) who were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

KEY POINTS

• Bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) are powerful prognostic variables in diffuse large B-cell lymphoma (DLBCL) patients. • High BLR and RI-bm are significantly associated with poor overall survival (OS) and relapse-free survival (RFS). • RI-bm and BLR represent suitable and noninvasive risk indicators in DLBCL patients.

MRI-based bone marrow radiomics for predicting cytogenetic abnormalities in multiple myeloma

AIM

To develop a radiomics signature applied to magnetic resonance imaging (MRI)-images to predict cytogenetic abnormalities in multiple myeloma (MM).

MATERIALS AND METHODS

Patients with newly diagnosed MM were enrolled retrospectively from March 2019 to September 2022. They were categorised into the high-risk cytogenetics (HRC) group and standard-risk cytogenetics (SRC) group. The patients were allocated randomly at a ratio of 7:3 into training and validation cohorts. Volumes of interest (VOI) was drawn manually on fat suppression T2-weighted imaging (FS-T2WI) and copied to the same location of the T1-weighted imaging (T1WI) sequence. Radiomics features were extracted from two sequences and selected by reproducibility and redundant analysis. The least absolute shrinkage selection operation (LASSO) algorithm was applied to build the radiomics signatures. The performance of the radiomics signatures to distinguish HRC with SRC was evaluated by ROC curves. The area under the curve (AUC), specificity, and sensitivity were also calculated.

RESULTS

A total of 105 MM patients were enrolled in this study. The four and 11 most significant and relevant features were selected separately from T1WI and FS-T2WI sequences to build the radiomics signatures based on the training cohort. Compared to the T1WI sequence, the radiomics signature based on the FS-T2WI sequence achieved better performance with AUCs of 0.896 and 0.729 in the training and validation cohorts respectively. A sensitivity of 0.833, specificity of 0.667, and Youden index of 0.500 were achieved for the FS-T2WI radiomics signature in the validation cohort.

CONCLUSIONS

The radiomics signature based on MRI provides a non-invasive and convenient tool to predict cytogenetic abnormalities in MM patients.

[The Value of Baseline PET/CT Imaging of Bone Marrow 18F-FDG Uptake Pattern in Predicting Prognosis of DLBCL]

OBJECTIVE

To investigate the prognostic value of bone marrow uptake pattern in 18F-deoxyglucose (18F-FDG) PET/CT imaging before diffuse large B-cell lymphoma (DLBCL) treatment.

METHODS

The clinical data of 156 patients with DLBCL were retrospectively analyzed. All patients underwent bone marrow biopsy, bone marrow smear, flow cytometry and 18F-FDG PET/CT scan before treatment. Taking normal liver 18F-FDG uptake as the standard, the bone marrow uptake patterns of patients were divided into three types: focal increased bone marrow uptake (fPET+), diffusely increased bone marrow uptake (dPET+), and normal bone marrow uptake (nPET). Survival analysis was performed using the Kaplan-Meier method, log-rank test was used for comparison of differences between groups, and multivariate Cox regression analysis was used to identify risk factors associated with prognosis.

RESULTS

Among the 156 patients, 17 cases were fPET+, 28 cases were dPET+, and 111 cases were nPET. Clinical diagnosis of bone marrow infiltration (BMI) was positive in 21 cases and negative in 135 cases. There were 62 cases of recurrence and progression, and 18 cases of death. Univariate analysis showed that Ann Arbor stage III/IV, B symptoms, NCCN-IPI score, lactate dehydrogenase (LDH), BMI+ and fPET+ were associated with progression-free survival (PFS) (all P < 0.05), while Ann Arbor stage III/IV, NCCN-IPI score, LDH, BMI+ and fPET+ were associated with overall survival (OS) (all P < 0.05). Multivariate analysis showed that Ann Arbor stage III/IV, LDH and fPET+ were independent predictors of PFS (all P < 0.05). There were no independent predictors of OS in multivariate analysis.

CONCLUSION

The bone marrow uptake pattern of 18F-FDG imaging in DLBCL patients before treatment has a predictive value for DLBCL, while fPET+ is an independent risk factor for PFS.

Assessment of lymph node area coverage with total marrow irradiation and implementation of total marrow and lymphoid irradiation using automated deep learning-based segmentation

BACKGROUND

Total marrow irradiation (TMI) and total marrow and lymphoid irradiation (TMLI) have the advantages. However, delineating target lesions according to TMI and TMLI plans is labor-intensive and time-consuming. In addition, although the delineation of target lesions between TMI and TMLI differs, the clinical distinction is not clear, and the lymph node (LN) area coverage during TMI remains uncertain. Accordingly, this study calculates the LN area coverage according to the TMI plan. Further, a deep learning-based model for delineating LN areas is trained and evaluated.

METHODS

Whole-body regional LN areas were manually contoured in patients treated according to a TMI plan. The dose coverage of the delineated LN areas in the TMI plan was estimated. To train the deep learning model for automatic segmentation, additional whole-body computed tomography data were obtained from other patients. The patients and data were divided into training/validation and test groups and models were developed using the "nnU-NET" framework. The trained models were evaluated using Dice similarity coefficient (DSC), precision, recall, and Hausdorff distance 95 (HD95). The time required to contour and trim predicted results manually using the deep learning model was measured and compared.

RESULTS

The dose coverage for LN areas by TMI plan had V100% (the percentage of volume receiving 100% of the prescribed dose), V95%, and V90% median values of 46.0%, 62.1%, and 73.5%, respectively. The lowest V100% values were identified in the inguinal (14.7%), external iliac (21.8%), and para-aortic (42.8%) LNs. The median values of DSC, precision, recall, and HD95 of the trained model were 0.79, 0.83, 0.76, and 2.63, respectively. The time for manual contouring and simply modified predicted contouring were statistically significantly different.

CONCLUSIONS

The dose coverage in the inguinal, external iliac, and para-aortic LN areas was suboptimal when treatment is administered according to the TMI plan. This research demonstrates that the automatic delineation of LN areas using deep learning can facilitate the implementation of TMLI.

Cross-Modal Imaging Reveals Nanoparticle Uptake Dynamics in Hematopoietic Bone Marrow during Inflammation

Nanoparticles have been employed to elucidate the innate immune cell biology and trace cells accumulating at inflammation sites. Inflammation prompts innate immune cells, the initial responders, to undergo rapid turnover and replenishment within the hematopoietic bone marrow. Yet, we currently lack a precise understanding of how inflammation affects cellular nanoparticle uptake at the level of progenitors of innate immune cells in the hematopoietic marrow. To bridge this gap, we aimed to develop imaging tools to explore the uptake dynamics of fluorescently labeled cross-linked iron oxide nanoparticles in the bone marrow niche under varying degrees of inflammation. The inflammatory models included mice that received intramuscular lipopolysaccharide injections to induce moderate inflammation and streptozotocin-induced diabetic mice with additional intramuscular lipopolysaccharide injections to intensify inflammation. In vivo magnetic resonance imaging (MRI) and fluorescence imaging revealed an elevated level of nanoparticle uptake at the bone marrow as the levels of inflammation increased. The heightened uptake of nanoparticles within the inflamed marrow was attributed to enhanced permeability and retention with increased nanoparticle intake by hematopoietic progenitor cells. Moreover, intravital microscopy showed increased colocalization of nanoparticles within slowly patrolling monocytes in these inflamed hematopoietic marrow niches. Our discoveries unveil a previously unknown role of the inflamed hematopoietic marrow in enhanced storage and rapid deployment of nanoparticles, which can specifically target innate immune cells at their production site during inflammation. These insights underscore the critical function of the hematopoietic bone marrow in distributing iron nanoparticles to innate immune cells during inflammation. Our findings offer diagnostic and prognostic value, identifying the hematopoietic bone marrow as an imaging biomarker for early detection in inflammation imaging, advancing personalized clinical care.

Feasibility of bone marrow edema detection using dual-energy cone-beam computed tomography

BACKGROUND

Dual-energy (DE) detection of bone marrow edema (BME) would be a valuable new diagnostic capability for the emerging orthopedic cone-beam computed tomography (CBCT) systems. However, this imaging task is inherently challenging because of the narrow energy separation between water (edematous fluid) and fat (health yellow marrow), requiring precise artifact correction and dedicated material decomposition approaches.

PURPOSE

We investigate the feasibility of BME assessment using kV-switching DE CBCT with a comprehensive CBCT artifact correction framework and a two-stage projection- and image-domain three-material decomposition algorithm.

METHODS

DE CBCT projections of quantitative BME phantoms (water containers 100-165 mm in size with inserts presenting various degrees of edema) and an animal cadaver model of BME were acquired on a CBCT test bench emulating the standard wrist imaging configuration of a Multitom Rax twin robotic x-ray system. The slow kV-switching scan protocol involved a 60 kV low energy (LE) beam and a 120 kV high energy (HE) beam switched every 0.5° over a 200° angular span. The DE CBCT data preprocessing and artifact correction framework consisted of (i) projection interpolation onto matched LE and HE projections views, (ii) lag and glare deconvolutions, and (iii) efficient Monte Carlo (MC)-based scatter correction. Virtual non-calcium (VNCa) images for BME detection were then generated by projection-domain decomposition into an Aluminium (Al) and polyethylene basis set (to remove beam hardening) followed by three-material image-domain decomposition into water, Ca, and fat. Feasibility of BME detection was quantified in terms of VNCa image contrast and receiver operating characteristic (ROC) curves. Robustness to object size, position in the field of view (FOV) and beam collimation (varied 20-160 mm) was investigated.

RESULTS

The MC-based scatter correction delivered > 69% reduction of cupping artifacts for moderate to wide collimations (> 80 mm beam width), which was essential to achieve accurate DE material decomposition. In a forearm-sized object, a 20% increase in water concentration (edema) of a trabecular bone-mimicking mixture presented as ∼15 HU VNCa contrast using 80-160 mm beam collimations. The variability with respect to object position in the FOV was modest (< 15% coefficient of variation). The areas under the ROC curve were > 0.9. A femur-sized object presented a somewhat more challenging task, resulting in increased sensitivity to object positioning at 160 mm collimation. In animal cadaver specimens, areas of VNCa enhancement consistent with BME were observed in DE CBCT images in regions of MRI-confirmed edema.

CONCLUSION

Our results indicate that the proposed artifact correction and material decomposition pipeline can overcome the challenges of scatter and limited spectral separation to achieve relatively accurate and sensitive BME detection in DE CBCT. This study provides an important baseline for clinical translation of musculoskeletal DE CBCT to quantitative, point-of-care bone health assessment.

Deep learning and atlas-based models to streamline the segmentation workflow of total marrow and lymphoid irradiation

PURPOSE

To improve the workflow of total marrow and lymphoid irradiation (TMLI) by enhancing the delineation of organs at risk (OARs) and clinical target volume (CTV) using deep learning (DL) and atlas-based (AB) segmentation models.

MATERIALS AND METHODS

Ninety-five TMLI plans optimized in our institute were analyzed. Two commercial DL software were tested for segmenting 18 OARs. An AB model for lymph node CTV (CTV_LN) delineation was built using 20 TMLI patients. The AB model was evaluated on 20 independent patients, and a semiautomatic approach was tested by correcting the automatic contours. The generated OARs and CTV_LN contours were compared to manual contours in terms of topological agreement, dose statistics, and time workload. A clinical decision tree was developed to define a specific contouring strategy for each OAR.

RESULTS

The two DL models achieved a median [interquartile range] dice similarity coefficient (DSC) of 0.84 [0.71;0.93] and 0.85 [0.70;0.93] across the OARs. The absolute median Dmean difference between manual and the two DL models was 2.0 [0.7;6.6]% and 2.4 [0.9;7.1]%. The AB model achieved a median DSC of 0.70 [0.66;0.74] for CTV_LN delineation, increasing to 0.94 [0.94;0.95] after manual revision, with minimal Dmean differences. Since September 2022, our institution has implemented DL and AB models for all TMLI patients, reducing from 5 to 2 h the time required to complete the entire segmentation process.

CONCLUSION

DL models can streamline the TMLI contouring process of OARs. Manual revision is still necessary for lymph node delineation using AB models.

Comparison of the accuracy of commercial two-point and multi-echo Dixon MRI for quantification of fat in liver, paravertebral muscles, and vertebral bone marrow

PURPOSE

Excess fat accumulation contributes significantly to metabolic dysfunction and diseases. This study aims to systematically compare the accuracy of commercially available Dixon techniques for quantification of fat fraction in liver, skeletal musculature, and vertebral bone marrow (BM) of healthy individuals, investigating biases and sex-specific influences.

METHOD

100 healthy White individuals (50 women) underwent abdominal MRI using two-point and multi-echo Dixon sequences. Fat fraction (FF), proton density fat fraction (PDFF) and T2* values were calculated for liver, paravertebral muscles (PVM) and vertebral BM (Th8-L5). Agreement and systematic deviations were assessed using linear correlation and Bland-Altman plots.

RESULTS

High correlations between FF and PDFF were observed in liver (r = 0.98 for women; r = 0.96 for men), PVM (r = 0.92 for women; r = 0.93 for men) and BM (r = 0.97 for women; r = 0.95 for men). Relative deviations between FF and PDFF in liver (18.92 % for women; 13.32 % for men) and PVM (1.96 % for women; 11.62 % for men) were not significant. Relative deviations in BM were significant (38.13 % for women; 27.62 % for men). Bias correction using linear models reduced discrepancies. T2* times were significantly shorter in BM (8.72 ms for women; 7.26 ms for men) compared to PVM (13.45 ms for women; 13.62 ms for men) and liver (29.47 ms for women; 26.35 ms for men).

CONCLUSION

While no significant differences were observed for liver and PVM, systematic errors in BM FF estimation using two-point Dixon imaging were observed. These discrepancies - mainly resulting from organ-specific T2* times - have to be considered when applying two-point Dixon approaches for assessment of fat content. As suitable correction tools, linear models could provide added value in large-scale epidemiological cohort studies. Sex-specific differences in T2* should be considered.

Intraosseous pressure measurement during iliac bone marrow biopsy: its feasibility and difference of IOP in diseased marrow and non-diseased marrow

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.

Detection performance and prognostic value of initial bone marrow involvement in diffuse large B-cell lymphoma: a single centre 18F-FDG PET/CT and bone marrow biopsy evaluation study

BACKGROUND

Detection of bone marrow involvement (BMI) in diffuse large B-cell lymphoma (DLBCL) typically relies on invasive bone marrow biopsy (BMB) that faces procedure limitations, while 18F-FDG PET/CT imaging offers a noninvasive alternative. The present study assesses the performance of 18F-FDG PET/CT in DLBCL BMI detection, its agreement with BMB, and the impact of BMI on survival outcomes.

PATIENTS AND METHODS

This retrospective study analyzes baseline 18F-FDG PET/CT and BMB findings in145 stage II-IV DLBCL patients, evaluating both performance of the two diagnostic procedures and the impact of BMI on survival.

RESULTS

DLBCL BMI was detected in 38 patients (26.2%) using PET/CT and in 18 patients (12.4%) using BMB. Concordant results were seen in 79.3% of patients, with 20.7% showing discordant results. Combining PET/CT and BMB data, we identified 29.7% of patients with BMI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for detecting DLBCL BMI were 88.4%, 100%, 100%, 95.3%, and 96.5%, respectively, while BMB showed lower sensitivity (41.9%) and NPV (46.8%). The median overall survival (OS) was not reached in any gender subgroup, with 5-year OS rates of 82% (total), 84% (female), and 80% (male) (p = 0.461), while different International Prognostic Index (IPI) groups exhibited varied 5-year OS rates: 94% for low risk (LR), 91% for low-intermediate risk (LIR), 84% for high-intermediate risk (HIR), and 65% for high risk (HR) (p = 0.0027). Bone marrow involvement did not impact OS significantly (p = 0.979).

CONCLUSIONS

18F-FDG PET/CT demonstrated superior diagnostic accuracy compared to BMB. While other studies reported poorer overall and BMI 5-year OS in DLBCL, our findings demonstrated favourable survival data.

Pattern of Bone Marrow Hypometabolism on 18 F-FDG PET CT in Systemic Lupus Erythematous-Associated Aplastic Anemia

ABSTRACT

We present the case of a 23-year-old woman with juvenile onset systemic lupus erythematous on a background of thrombotic thrombocytopenic purpura, who was referred for 18 F-FDG PET CT scan due to pyrexia of unknown origin with raised inflammatory markers, severe thrombocytopenia, and anemia. An interesting pattern of predominantly photopenic hypometabolic bone marrow activity was demonstrated on 18 F-FDG PET CT.

18F-FDG PET/CT-Based Radiomics Nomogram for Prediction of Bone Marrow Involvement in Pediatric Neuroblastoma: A Two-Center Study

RATIONALE AND OBJECTIVES

To assess the predictive ability of an 18F-FDG PET/CT-based radiomics nomogram for bone marrow involvement in pediatric neuroblastoma.

MATERIALS AND METHODS

A total of 241 neuroblastoma patients who underwent 18F-FDG PET/CT at two medical centers were retrospectively evaluated. Data from center A (n = 200) were randomized into a training cohort (n = 140) and an internal validation cohort (n = 60), while data from center B (n = 41) constituted the external validation cohort. For each patient, two regions of interest were defined using the tumor and axial skeleton. The clinical factors and radiomics features were derived to construct the clinical and radiomics models. The radiomics nomogram was built by combining clinical factors and radiomics features. The area under the receiver operating characteristic curves (AUCs) were used to assess the performance of the models.

RESULTS

Radiomics models created from tumor and axial skeleton achieved AUCs of 0.773 and 0.900, and the clinical model had an AUC of 0.858 in the training cohort. By incorporating clinical risk factors and axial skeleton-based radiomics features, the AUC of the radiomics nomogram in the training cohort, internal validation cohort, and external validation cohort was 0.932, 0.887, and 0.733, respectively.

CONCLUSION

The axial skeleton-based radiomics model performed better than the tumor-based radiomics model in predicting bone marrow involvement. Moreover, the radiomics nomogram showed that combining axial skeleton-based radiomics features with clinical risk factors improved their performance.

Comparative analysis of bone turnover markers in bone marrow and peripheral blood: implications for osteoporosis

INTRODUCTION

This study examines bone turnover marker (BTM) variations between bone marrow and peripheral blood in osteoporotic and non-osteoporotic patients. BTMs offer insights into bone remodeling, crucial for understanding osteoporosis.

METHODS

A total of 133 patients were categorized into osteoporotic and non-osteoporotic cohorts. BTMs-C-telopeptide cross-linked type 1 collagen (β-CTX), serum osteocalcin (OC), Procollagen type I N-propeptide (P1NP), 25(OH)D-were measured in bone marrow and peripheral blood. Lumbar spine bone mineral density (BMD) was assessed.

RESULTS

Osteoporotic patients exhibited elevated β-CTX and OC levels in peripheral blood, indicating heightened bone resorption and turnover. β-CTX levels in osteoporotic bone marrow were significantly higher. Negative correlations were found between peripheral blood β-CTX and OC levels and lumbar spine BMD, suggesting their potential as osteoporosis severity indicators. No such correlations were observed with bone marrow markers. When analyzing postmenopausal women separately, we obtained consistent results.

CONCLUSIONS

Elevated β-CTX and OC levels in osteoporotic peripheral blood highlight their diagnostic significance. Negative β-CTX and OC-BMD correlations underscore their potential for assessing osteoporosis severity. Discrepancies between peripheral blood and bone marrow markers emphasize the need for further exploration. This research advances our understanding of BTM clinical applications in osteoporosis diagnosis and treatment.

Association of anatomical variants of the sacroiliac joint with bone marrow edema in patients with axial spondyloarthritis

OBJECTIVE

To determine the prevalence of sacroiliac joint variants in patients with axial spondyloarthritis (axSpA) using MRI-based synthetic CT images and to evaluate their relationships with the presence of bone marrow edema, as this may potentially complicate diagnosing active sacroiliitis on MRI in patients with suspected axSpA.

METHODS

172 patients were retrospectively included. All patients underwent MRI because of clinical suspicion of sacroiliitis. The diagnosis of axSpA was made by a tertiary hospital rheumatologist. Two readers independently determined the presence of bone marrow edema and the presence of one or more of the nine known sacroiliac joint (SIJ) variants.

RESULTS

SIJ variants were common in axSpA patients (82.9%) and the non-SpA group (85.4%); there were no significant differences in prevalence. Bone marrow edema was frequently found in axSpA (86.8%) and non-SpA patients (34%). AxSpA patients with SIJ variants (except for accessory joint) demonstrated 4 to 10 times higher odds for bone marrow edema, however not statistically significant. The more variants were present in this group, the higher the chance of bone marrow edema. However, some multicollinearity cannot be excluded, since bone marrow edema is very frequent in the axSpA group by definition.

CONCLUSION

SIJ variants are common in axSpA and non-SpA patients. SIJ variants were associated with higher prevalence of bone marrow edema in axSpA patients, potentially due to altered biomechanics, except for accessory joint which may act as a stabilizer.

Quantitative assessment of bone marrow infiltration and characterization of tumor burden using dual-layer spectral CT in patients with multiple myeloma

BACKGROUND

The aim of the study was to evaluate whether virtual calcium subtraction (VNCa) image extracted from dual-layer spectral CT could estimate bone marrow (BM) infiltration with MRI as the reference standard and characterize tumor burden in patients with multiple myeloma (MM).

PATIENTS AND METHODS

Forty-seven patients with newly diagnosed MM were retrospectively enrolled. They had undergone whole-body low-dose dual-layer spectral CT (DLCT) and whole-body MRI within one week. VNCa images with calcium-suppressed (CaSupp) indices ranging from 25 to 95 at an interval of 10 and apparent diffusion coefficient (ADC) maps were quantitatively analyzed on vertebral bodies L1-L5 at the central slice of images. The optimal combination was selected by correlation analysis between CT numbers and ADC values. Then, it was used to characterize tumor burden by correlation analysis and receiver operating characteristic (ROC) curves analysis, including plasma cell infiltration rate (PCIR), high serum-free light chains (SFLC) ratio and the high-risk cytogenetic (HRC) status.

RESULTS

The most significant quantitative correlation between CT numbers of VNCa images and ADC values could be found at CaSupp index 85 for averaged L1-L5 (r = 0.612, p < 0.001). It allowed quantitative evaluation of PCIR (r = 0.835, p < 0.001). It could also anticipate high SFLC ratio and the HRC status with area under the curve (AUC) of 0.876 and 0.760, respectively.

CONCLUSIONS

The VNCa measurements of averaged L1-L5 showed the highest correlation with ADC at CaSupp index 85. It could therefore be used as additional imaging biomarker for non-invasive assessment of tumor burden if ADC is not feasible.

FDG PET/CT may replace bone marrow biopsy for the evaluation of bone marrow involvement in selected mature T- and natural killer-cell lymphomas: A meta-analysis

PURPOSE

To systematically determine the role of FDG PET/CT for the diagnosis of bone marrow involvement in mature T- and natural killer (NK)-cell lymphomas.

METHODS

The PubMed, Embase and Cochrane Library databases were searched to identify eligible studies. Data extraction and quality assessment were independently conducted. Then, pooled diagnostic performance with the 95 % confidence interval (CI) was calculated and further analyzed based on different interpretation criteria, tumor type and stage.

RESULTS

Fifteen studies were eventually included for quantitative analysis. Overall, the methodological quality of included studies was acceptable. For detecting bone marrow involvement, FDG PET/CT achieved a poor sensitivity of 0.62 (95 % CI, 0.48-0.71) and a reasonable specificity of 0.92 (95 % CI, 0.87-0.96). Similar performance was observed for the specific type of extranodal NK/T-cell lymphoma (ENKTCL). In early-stage patients revealed by PET/CT, extremely small proportion (2/777) showed positive bone marrow biopsy, especially for the specific type of ENKTCL, whereas in advanced-stage patients, the specificity of FDG PET/CT dropped to 0.77 (95 % CI, 0.72-0.82). Regarding the interpretation, both diffuse and focal increased uptake patterns as positivity may result in increased sensitivity but decreased specificity compared with focal pattern alone as positivity.

CONCLUSIONS

FDG PET/CT demonstrated excellent negative predictive value for detecting marrow involvement in early-stage patients with mature T- and NK-cell lymphomas, especially the ENKTCL. Conversely, FDG PET/CT showed poor performance for the diagnosis of bone marrow involvement in advanced-stage patients.

Carboxyl-Modified Quantum Dots for NIR-IIb Bone Marrow Imaging

Real-time, noninvasive, and nonradiative bone imaging can directly visualize bone health but requires bone-targeted probes with high specificity. Herein, we propose that carboxyl-rich fluorescent nanoprobes are easily absorbed by macrophages in bone marrow during circulation, enabling optical bone marrow imaging in vivo. We used PbS/CdS core-shell quantum dots with NIR-IIb (1500-1700 nm) emission as substrates to prepare the carboxyl-rich nanoprobe. In vivo NIR-IIb fluorescence imaging with the nanoprobes showed high resolution and penetration depth in bone tissues and allowed for imaging-guided fracture diagnosis. Bone tissue slices showed substantial accumulation of carboxyl nanoprobes in the bone marrow and strong colocalization with macrophages. Similar results with CdSe quantum dots and an organic nanofluorophore suggest that carboxyl surface modification is effective to achieve bone marrow targeting, providing a novel strategy for developing bone/bone marrow imaging probes.

[The detecting value of virtual non-calcium technique of dual-energy CT for bone marrow edema around nontraumatic osteonecrosis of the femoral head]

Objective: To evaluate the value of virtual non-calcium (VNCa) technique of dual-energy CT (DECT) for detecting bone marrow edema (BME) around nontraumatic osteonecrosis of the femoral head (ONFH) using MRI as reference standard. Methods: Nontraumatic ONFH patients were prospectively studied in the Fourth Medical Center of Chinese PLA General Hospital from October 2022 to May 2023, and their MRI and DECT images were analyzed. The diagnostic efficiency of the subjective assessment of BME around ONFH by two radiologists in VNCa color-coded images were calculated using the MRI results as the reference standard. The BME ranges were compared between VNCa images and MRI. Traditional CT values and VNCa CT values were compared between normal bone marrow and BME. The receiver operator characteristic (ROC) curve was established based on the statistically different CT values, and the area under the curve (AUC) was calculated to find the threshold to distinguish normal bone marrow from BME and evaluate the diagnostic efficacy. Results: Thirty patients with ONFH were included, including 24 males and 6 females, aged (39±12) years. There were 18 bilateral hips and 12 unilateral hips, with a total of 48 hips, 34 hips of which showed BME on MRI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of subjective detection of BME on VNCa color coded maps by two physicians were 97.1% (33/34) and 97.1% (33/34), 92.9% (13/14) and 71.4% (10/14), 97.1% (33/34) and 89.2% (33/37), 92.9% (13/14) and 90.9% (10/11), 95.8% (46/48) and 89.6% (43/48), respectively, with no statistical difference (all P>0.05).There was no statistical difference between VNCa color-coded images and MRI in the BME range (P=1.160). The traditional CT values measured by the two radiologists were in good agreement with VNCa CT values, with intraclass correlation coefficient (ICC) of 0.948 (95%CI: 0.908-0.971) and 0.982 (95%CI: 0.969-0.990), respectively. The traditional CT value of normal bone marrow was (400.7±82.8) HU, and that of BME was (443.7±65.7) HU, with no statistical difference (P=0.062). The VNCa CT value of normal bone marrow was (-103.1±27.8) HU, and that of BME was (-32.9±25.7) HU, with statistical difference (P<0.001). The AUC of distinguishing normal bone marrow from BME based on VNCa CT value was 0.958 (95%CI: 0.857-0.995). The best cut-off value was -74.5 HU, and when the VNCa CT value was higher than -74.5 HU, the sensitivity, specificity, PPV, NPV and accuracy of diagnosing BME were 97.1%, 92.9%, 97.1%, 92.9% and 95.8 %, respectively. Conclusion: The VNCa technique of DECT has high efficiency in detecting BME around ONFH, and can accurately demonstrate the range of BME.

Differentiation of bone metastases from benign red marrow depositions: utilizing qualitative and quantitative analysis of conventional T1-weighted imaging and fat-suppressed T2-weighted imaging

OBJECTIVES

To distinguish bone metastases (BMs) from benign red marrow depositions (BRMs) by qualitative and quantitative analyses of T1-weighted imaging and fat-suppressed T2-weighted imaging (T2 FS).

METHODS

For 75 lesions including 38 BMs and 37 BRMs, two radiologists independently evaluated magnetic resonance images by qualitative (signal intensity [SI] of lesions compared to that of normal muscle [NM] or normal bone marrow [NBM]) and quantitative (parameters of the region of interests in the lesions, including T1 ratio [T1 SI ratio of lesion and NM], T2FMu ratio [T2 FS SI ratio of lesion and NM], and T2FMa ratio [T2 FS SI ratio of lesion and NBM]) analyses.

RESULTS

Hyperintensity relative to NM or NBM on T2 FS was more frequent in BMs than in BRMs (100% vs 59.5%-78.4%, respectively; P ≤ 0.001) but also was present in more than half of BRMs. All quantitative parameters showed a significant difference between BMs and BRMs (T1 ratio, 1.075 vs 1.227 [P = 0.002]; T2FMu ratio, 2.094 vs 1.282 [P < 0.001]; T2FMa ratio, 3.232 vs 1.810 [P < 0.001]). The receiver operating characteristics areas under the curves of T2FMu and T2FMa ratios were clinically useful (0.781 and 0.841, respectively) and did not demonstrate statistically significant differences.

CONCLUSIONS

The quantitative analysis of T2 FS facilitates distinguishing between BMs and BRMs, regardless of whether the reference was NM or NBM.

ADVANCES IN KNOWLEDGE

Quantitative parameters derived from T2 FS facilitate differentiation of BMs BRMs without additional scans. The role of NBM as an internal standard for T2 FS to differentiate between BMs and BRMs is similar to that of NM.

CDC-NET: a cell detection and confirmation network of bone marrow aspirate images for the aided diagnosis of AML

Standardized morphological evaluation in pathology is usually qualitative. Classifying and qualitatively analyzing the nucleated cells in the bone marrow aspirate images based on morphology is crucial for the diagnosis of acute myoid leukemia (AML), acute lymphoblastic leukemia (ALL), and Myelodysplastic syndrome (MDS), etc. However, it is time-consuming and difficult to accurately identify nucleated cells and calculate the percentage of the cells because of the complexity of bone marrow aspirate images. This paper proposed a deep learning analysis model of bone marrow aspirate images, termed Cell Detection and Confirmation Network (CDC-NET), for the aided diagnosis of AML by improving the accuracy of cell detection and recognition. Specifically, we take the nucleated cells in the bone marrow aspirate images as the detection objects to establish the model. Since some cells from different categories have similar morphology, classification error is inevitable. We design a confirmation network in which multiple trained classifiers work as pathologists to confirm the cell category by a voting method. To demonstrate the effectiveness of the proposed approach, experiments on clinical microscopic datasets are conducted. The Recall and Precision of CDC-NET are 78.54% and 91.74% respectively, and the missed rate of our method is lower than those of the other popular methods. The experimental results demonstrated that the proposed model has the potential for the pathological analysis of aspirate smears and the aided diagnosis of AML.

Association between knee magnetic resonance imaging markers and knee symptoms over 6-9 years in young adults

OBJECTIVES

To describe associations between MRI markers with knee symptoms in young adults.

METHODS

Knee symptoms were assessed using the WOMAC scale during the Childhood Determinants of Adult Health Knee Cartilage study (CDAH-knee; 2008-2010) and at the 6- to 9-year follow-up (CDAH-3; 2014-2019). Knee MRI scans obtained at baseline were assessed for morphological markers (cartilage volume, cartilage thickness, subchondral bone area) and structural abnormalities [cartilage defects and bone marrow lesions (BMLs)]. Univariable and multivariable (age, sex, BMI adjusted) zero-inflated Poisson (ZIP) regression models were used for analysis.

RESULTS

The participants' mean age in CDAH-knee and CDAH-3 were 34.95 (s.d. 2.72) and 43.27 (s.d. 3.28) years, with 49% and 48% females, respectively. Cross-sectionally, there was a weak but significant negative association between medial femorotibial compartment (MFTC) [ratio of the mean (RoM) 0.99971084 (95% CI 0.9995525, 0.99986921), P < 0.001], lateral femorotibial compartment (LFTC) [RoM 0.99982602 (95% CI 0.99969915, 0.9999529), P = 0.007] and patellar cartilage volume [RoM 0.99981722 (95% CI 0.99965326, 0.9999811), P = 0.029] with knee symptoms. Similarly, there was a negative association between patellar cartilage volume [RoM 0.99975523 (95% CI 0.99961427, 0.99989621), P = 0.014], MFTC cartilage thickness [RoM 0.72090775 (95% CI 0.59481806, 0.87372596), P = 0.001] and knee symptoms assessed after 6-9 years. The total bone area was negatively associated with knee symptoms at baseline [RoM 0.9210485 (95% CI 0.8939677, 0.9489496), P < 0.001] and 6-9 years [RoM 0.9588811 (95% CI 0.9313379, 0.9872388), P = 0.005]. The cartilage defects and BMLs were associated with greater knee symptoms at baseline and 6-9 years.

CONCLUSION

BMLs and cartilage defects were positively associated with knee symptoms, whereas cartilage volume and thickness at MFTC and total bone area were weakly and negatively associated with knee symptoms. These results suggest that the quantitative and semiquantitative MRI markers can be explored as a marker of clinical progression of OA in young adults.

Association of biochemical markers with bone marrow lesion changes on imaging-data from the Foundation for the National Institutes of Health Osteoarthritis Biomarkers Consortium

BACKGROUND

To assess the prognostic value of short-term change in biochemical markers as it relates to bone marrow lesions (BMLs) on MRI in knee osteoarthritis (OA) over 24 months and, furthermore, to assess the relationship between biochemical markers involved with tissue turnover and inflammation and BMLs on MRI.

METHODS

Data from the Foundation for the National Institutes of Health OA Biomarkers Consortium within the Osteoarthritis Initiative (n = 600) was analyzed. BMLs were measured according to the MRI Osteoarthritis Knee Score (MOAKS) system (0-3), in 15 knee subregions. Serum and urinary biochemical markers assessed were as follows: serum C-terminal crosslinked telopeptide of type I collagen (CTX-I), serum crosslinked N-telopeptide of type I collagen (NTX-I), urinary CTX-Iα and CTX-Iβ, urinary NTX-I, urinary C-terminal cross-linked telopeptide of type II collagen (CTX-II), serum matrix metalloproteinase (MMP)-degraded type I, II, and III collagen (C1M, C2M, C3M), serum high sensitivity propeptide of type IIb collagen (hsPRO-C2), and matrix metalloproteinase-generated neoepitope of C-reactive protein (CRPM). The association between change in biochemical markers over 12 months and BMLs over 24 months was examined using regression models adjusted for covariates. The relationship between C1M, C2M, C3M, hsPRO-C2, and CRPM and BMLs at baseline and over 24 months was examined.

RESULTS

Increases in serum CTX-I and urinary CTX-Iβ over 12 months were associated with increased odds of changes in the number of subregions affected by any BML at 24 months. Increase in hsPRO-C2 was associated with decreased odds of worsening in the number of subregions affected by any BML over 24 months. C1M and C3M were associated with BMLs affected at baseline.

CONCLUSIONS

Short-term changes in serum CTX-I, hsPRO-C2, and urinary CTX-Iβ hold the potential to be prognostic of BML progression on MRI. The association of C1M and C3M with baseline BMLs on MRI warrants further investigation.

Associations of gestational diabetes and proton density fat fraction of vertebral bone marrow and paraspinal musculature in premenopausal women

Background and objective

Fat content in bones and muscles, quantified by magnetic resonance imaging (MRI) as a proton density fat fraction (PDFF) value, is an emerging non-invasive biomarker. PDFF has been proposed to indicate bone and metabolic health among postmenopausal women. Premenopausal women with a history of gestational diabetes (GDM) carry an increased risk of developing type 2 diabetes and an increased risk of fractures. However, no studies have investigated the associations between a history of GDM and PDFF of bone or of paraspinal musculature (PSM), composed of autochthonous muscle (AM) and psoas muscle, which are responsible for moving and stabilizing the spine. This study aims to investigate whether PDFF of vertebral bone marrow and of PSM are associated with a history of GDM in premenopausal women.

Methods

A total of 37 women (mean age 36.3 ± 3.8 years) who were 6 to 15 months postpartum with (n=19) and without (n=18) a history of GDM underwent whole-body 3T MRI, including a chemical shift encoding-based water-fat separation. The PDFF maps were calculated for the vertebral bodies and PSM. The cross-sectional area (CSA) of PSM was obtained. Associations between a history of GDM and PDFF were assessed using multivariable linear and logistic regression models.

Results

The PDFF of the vertebral bodies was significantly higher in women with a history of GDM (GDM group) than in women without (thoracic: median 41.55 (interquartile range 32.21-49.48)% vs. 31.75 (30.03-34.97)%; p=0.02, lumbar: 47.84 (39.19-57.58)% vs. 36.93 (33.36-41.31)%; p=0.02). The results remained significant after adjustment for age and body mass index (BMI) (p=0.01-0.02). The receiver operating characteristic curves showed optimal thoracic and lumbar vertebral PDFF cutoffs at 38.10% and 44.18%, respectively, to differentiate GDM (AUC 0.72 and 0.73, respectively, sensitivity 0.58, specificity 0.89). The PDFF of the AM was significantly higher in the GDM group (12.99 (12.18-15.90)% vs. 10.83 (9.39-14.71)%; p=0.04) without adjustments, while the CSA was similar between the groups (p=0.34).

Conclusion

A history of GDM is significantly associated with a higher PDFF of the vertebral bone marrow, independent of age and BMI. This statistical association between GDM and increased PDFF highlights vertebral bone marrow PDFF as a potential biomarker for the assessment of bone health in premenopausal women at risk of diabetes.

Liver Fat, Bone Marrow Adipose Tissue, and Bone Mineral Density in Children With Overweight

CONTEXT

Hepatic steatosis is associated with decreased bone mineral density (BMD). Bone marrow fat fraction (BMFF) could play a role in this relationship in children with obesity.

OBJECTIVE

The objectives of this work were (i) to examine the relationship between the lumbar spine (LS) BMFF and BMD, and (ii) to explore the mediating role of LS-BMFF on the relationship between percentage hepatic fat with LS-BMD in preadolescent children with overweight/obesity.

METHODS

Hepatic fat and LS-BMFF (magnetic resonance imaging) and areal LS-BMD (LS-aBMD, dual-energy x-ray absorptiometry) were measured in 106 children (aged 10.6 ± 1.1 years, 53.8% girls) with overweight/obesity.

RESULTS

LS-BMFF was inversely associated with LS-aBMD (r = -0.313; P = .001) and directly related with percentage hepatic fat (r = 0.276; P = .005). LS-BMFF was significantly greater in children with than without hepatic steatosis (P = .003; Cohen's d: 0.61; 95% CI, -0.21 to 1.0), while no significant difference was seen between children with overweight and those with obesity (P = .604; Cohen's d: 0.16; 95% CI, -0.21-0.55). Mediating analysis indicated that LS-BMFF is an important mediator (50%) in the association of hepatic fat with lower LS-aBMD (indirect effect: β = -.076; 95% CI, -0.143 to -0.015).

CONCLUSION

These findings suggest that hepatic steatosis, rather than overall excess adiposity, is associated with greater bone marrow adipose tissue in preadolescent children with overweight/obesity, which in turn, is related to lower BMD. Hepatic steatosis could be a potential biomarker of osteoporosis risk, and a therapeutic target for interventions that aim to reduce not only hepatic steatosis, but for those designed to improve bone health in such children.

(Smoldering) multiple myeloma: mismatch between tumor load estimated from bone marrow biopsy at iliac crest and tumor load shown by MRI

In multiple myeloma and its precursor stages, precise quantification of tumor load is of high importance for diagnosis, risk assessment, and therapy response evaluation. Both whole-body MRI, which allows to investigate the complete bone marrow of a patient, and bone marrow biopsy, which is commonly used to assess the histologic and genetic status, are relevant methods for tumor load assessment in multiple myeloma. We report on a series of striking mismatches between the plasma cell infiltration estimating the tumor load from unguided biopsies of the bone marrow at the posterior iliac crest and the tumor load assessment from whole-body MRI.

Relative fat fraction of malignant bone lesions from breast cancer, prostate cancer and myeloma are significantly lower than normal bone marrow and shows excellent interobserver agreement

OBJECTIVES

To compare relative fat fraction (rFF) of active bone lesions from breast, prostate and myeloma malignancies and normal bone marrow; to assess its inter-reader agreement.

METHODS

Patients with breast (n = 26), myeloma (n = 32) and prostate cancer (n = 52) were retrospectively evaluated. 110 baseline rFF maps from whole-body MRI were reviewed by two radiologists. Regions of interest for up to four focal active lesions in each patient were drawn on rFF maps, one each at the cervicothoracic spine, lumbosacral spine, pelvis and extremity. The mean and standard deviation of rFF were recorded. The rFF of normal marrow was measured in the pelvis for patients without diffuse bone disease (n = 88). We compared the rFF of malignant bone lesions and normal marrow using Mann-Whitney test. Interobserver agreement was assessed by interclass correlation coefficient.

RESULTS

Malignant bone lesions showed significantly lower median rFF (13.87%) compared with normal marrow (89.76%) with little overlap (p < 0.0001). There was no significant difference in the median rFF of malignant lesions from breast (14.46%), myeloma (13.12%) and prostate cancer (13.67%) (p > 0.017, Bonferroni correction) and in the median rFF of bone disease according to their anatomical locations (p > 0.008, Bonferroni correction). There was excellent interobserver agreement (0.95).

CONCLUSION

The low rFF of active bone lesions in breast, prostate and myeloma malignancies provides high image contrast relative to normal marrow that may be used to detect bone metastases.

ADVANCES IN KNOWLEDGE

This study shows the importance of rFF towards detecting bone metastases.

A simplified general schema for rapid single time-point marrow predictive dosimetry

The red marrow is often the dose-limiting organ in systemic radionuclide therapy. However, multi-time-point personalised predictive dosimetry is resource intensive and impractical for routine clinical implementation. Single-time-point methods are a reasonable alternative for streamlining dosimetric workflows. However, there is a lack of single time-point methodology specific for the marrow. A simplified schema for rapid marrow predictive dosimetry is proposed based on direct image quantification of marrow radioconcentration, which may be generalised to most forms of systemic radionuclide therapy.

Anatomic Approach to Common and Uncommon Manifestations of Thoracic Leukemias with Radiologic-Pathologic Correlation

Leukemias are hematopoietic malignancies characterized by the production of abnormal leukocytes in the bone marrow. Clinical manifestations arise from either bone marrow suppression or leukemic organ infiltration. Lymphadenopathy is the most common direct manifestation of intrathoracic leukemia. However, leukemic cells may also infiltrate the lungs, pleura, heart, bones, and soft tissues. Pulmonary complications in patients with leukemia typically include pneumonia, hemorrhage, pulmonary edema, and sequelae of leukemia treatment. However, pulmonary abnormalities can also be related directly to leukemia, including leukemic pulmonary infiltration. The direct, non-treatment-related effects of leukemia on intrathoracic structures will be the focus of this imaging essay. Given the typical anatomic approach for image interpretation, an organ-based depiction of common and less common intrathoracic findings directly caused by leukemic involvement is presented, emphasizing imaging findings with pathologic correlations. Keywords: Leukemia, Pulmonary, Thorax, Soft Tissues/Skin, Hematologic, Bone Marrow © RSNA, 2023.

Value of Edema-like Marrow Signal Intensity in Diagnosis of Joint Pain: Radiologists' Perspective

Musculoskeletal pain is a significant contributor to disability. The mechanism and target of the treatment should be optimized by imaging, but currently no accepted gold standard exists to image pain. In addition to end-organ pathology, other mediators also contribute to nociception, such as angiogenesis, axonal extension, immunologic modulation, and central sensitization. Recent research indicates that local inflammation is a significant contributor to pain in the extremities; therefore, we focus here on edema-like marrow signal intensity (ELMSI). We examine both the relevance of ELMSI for pain and novel imaging techniques.

Apparent diffusion coefficient measurements of bone marrow infiltration patterns in multiple myeloma for the assessment of tumor burden - a feasibility study

BACKGROUND

The purpose of our study was to explore and compare the tumor burden of different bone marrow infiltration patterns and evaluate the feasibility of apparent diffusion coefficient (ADC) value to identify patterns in multiple myeloma (MM).

PATIENTS AND METHODS

Ninety-three patients with newly diagnosed multiple myeloma and 23 controls had undergone routine magnetic resonance imaging (MRI) and diffusion-weighted MRI (DWI) from January 2019 to November 2020. Five bone marrow (BM) infiltration patterns were allocated according to routine MRI. The laboratory data and ADC values of patterns were analyzed and compared. ROC analysis was used to establish the best diagnostic ADC threshold value for identifying these patterns and distinguishing normal pattern from controls. Besides, the correlation between the ADC values of diffuse pattern and the plasma cells ratio was assessed.

RESULTS

The values of hemoglobin, beta-2 microglobulin (β2-MG), plasma cell, M protein, the percentages of stage, high-risk fluorescence in situ hybridization, and ADC values showed significant difference among patterns. ADCmean at a specific value (368.5×10-6 mm2/s) yielded a maximum specificity (95.5%) and sensitivity (92.0%) in diagnosing MM. A specific value (335.5×10-6mm2/s) yielded a maximum specificity (84.7%) and sensitivity (88.0%) in discriminating visually normal pattern in MM from controls. There was a moderate positive correlation between the plasma cells ratio and ADCs of diffuse infiltration patterns (r = 0.648, P < 0.001).

CONCLUSIONS

The bone marrow infiltration patterns in MM patients can indicate the tumor burden and ADC value has the ability to discriminate these patterns objectively.

Foot and Ankle Bone Marrow Edema Assessment in Long Distance Runners

BACKGROUND

The clinical significance of foot and ankle bone marrow edema (BME) is poorly understood.

METHODS

Magnetic resonance imaging (MRI) and the visual analog scale (VAS) pain scores were collected for 17 runners who participated in the Twin Cities Marathon, immediately postmarathon and at a 6-week follow-up. Bone marrow edema lesions were classified using lesion frequency, anatomical location, and grading scale change to calculate a BME score for each affected bone. Spearman rank correlation coefficient test was used to identify a possible correlation between VAS and postmarathon BME. A paired Student t test was used to detect differences between total mileage ran 6 weeks postmarathon in participants with or without BME.

RESULTS

After completing the marathon, 8 BME lesions were identified in 5 participants (29.4%; 5/17), 3 were men, and 2 were women, with a mean age of 33.8 years (range: 24-52), and BMI of 22.9 ± 4. All lesions were resolved on 6-week follow-up imaging. VAS pain scores did not correlate with postmarathon BME. A significant difference in total miles logged over 6 weeks postmarathon could not be found among participants with and without BME.

CONCLUSION

Foot and ankle BME changes identified by MRI were not correlated to clinical symptoms and may resolve with self-directed activity in less time than other areas of the lower extremity.

LEVEL OF EVIDENCE

Level II, Prospective Cohort Study.

Machine Learning Pipeline for Predicting Bone Marrow Edema Along the Sacroiliac Joints on Magnetic Resonance Imaging

OBJECTIVE

We aimed to develop and validate a fully automated machine learning (ML) algorithm that predicts bone marrow edema (BME) on a quadrant level in sacroiliac (SI) joint magnetic resonance imaging (MRI).

METHODS

A computer vision workflow automatically locates the SI joints, segments regions of interest (ilium and sacrum), performs objective quadrant extraction, and predicts presence of BME, suggestive of inflammatory lesions, on a quadrant level in semicoronal slices of T1/T2-weighted MRI scans. Ground truth was determined by consensus among human readers. The inflammation classifier was trained using a ResNet18 backbone and five-fold cross-validated on scans of patients with spondyloarthritis (SpA) (n = 279), postpartum individuals (n = 71), and healthy subjects (n = 114). Independent SpA patient MRI scans (n = 243) served as test data set. Patient-level predictions were derived from aggregating quadrant-level predictions, ie, at least one positive quadrant.

RESULTS

The algorithm automatically detects the SI joints with a precision of 98.4% and segments ilium/sacrum with an intersection over union of 85.6% and 67.9%, respectively. The inflammation classifier performed well in cross-validation: area under the curve (AUC) 94.5%, balanced accuracy (B-ACC) 80.5%, and F1 score 64.1%. In the test data set, AUC was 88.2%, B-ACC 72.1%, and F1 score 50.8%. On a patient level, the model achieved a B-ACC of 81.6% and 81.4% in the cross-validation and test data set, respectively.

CONCLUSION

We propose a fully automated ML pipeline that enables objective and standardized evaluation of BME along the SI joints on MRI. This method has the potential to screen large numbers of patients with (suspected) SpA and is a step closer towards artificial intelligence-assisted diagnosis and follow-up.

Greater medial proximal tibial slope is associated with bone marrow lesions in middle-aged women with early knee osteoarthritis

BACKGROUND

Bone marrow lesion (BML) is an important magnetic resonance finding (MRI) finding that predicts knee osteoarthritis. The purpose of this study was to investigate the influence of proximal tibial morphology on BML, including the spreading root sign (SRS), in women without radiographic knee osteoarthritis (OA). It was hypothesized that varus alignment and a greater posterior tibial slopes (PTS) are associated with BML.

MATERIALS AND METHODS

A total of 359 female volunteers without knee OA who were participants in the Iwaki Health Promotion Project in 2017 or 2019 were enrolled. Participants were divided into the non-OA and early knee OA (EKOA) groups based on the Luyten's classification criteria. The presence of pathological cartilage lesions, BMLs, attritions, meniscal lesions and effusions was scored on T2-weighted fat-suppressed magnetic resonance imaging (MRI) according to the Whole-Organ MRI Scoring system. The medial proximal tibial angle (MPTA) and medial and lateral PTS (MPTS and LPTS, respectively) were measured. Regression and receiver operating characteristic (ROC) analyses were performed to reveal the relationship between BMLs and proximal tibial morphological parameters.

RESULTS

Of the 359 participants, 54 (15%) were classified as having EKOA. The prevalence of cartilage lesions, BMLs, attritions, meniscal lesions and effusions was higher in the EKOA group than in the non-OA group. The two groups had no significant difference in the proximal tibial parameters. Regression analysis revealed that age and a smaller MPTA were associated with BML in both groups. Attrition (p = 0.029) and the MPTS (p = 0.025) were positively associated with BML in the EKOA group.

CONCLUSION

The prevalence of BMLs was higher in women with EKOA and correlated with the varus and greater posterior slopes in those without radiographic knee OA.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Preliminary Study of Confounder-Corrected Fat Fraction and R2* Mapping of Bone Marrow in Children With Acute Leukemia

BACKGROUND

The bone marrow (BM) evaluation of acute leukemia (AL) mainly depends on invasive BM puncture biopsy. Noninvasive and accurate MR examination technology has potential clinical application value in the BM evaluation of AL patients. Multi-gradient-echo (MGRE) has been found useful to evaluate changes in BM fat and iron content, but has not yet been applied in AL.

PURPOSE

To explore the diagnostic capability of BM infiltration of quantitative BM fat fraction (FF) and R2* values obtained from a 3D MGRE sequence in children with primary AL.

STUDY TYPE

Prospective.

POPULATION/SUBJECTS

Sixty-two pediatric patients with untreated AL and 68 healthy volunteers. AL patients were divided into acute lymphoblastic leukemia (ALL) (n = 39) and acute myeloid leukemia (AML) (n = 23) groups.

FIELD STRENGTH/SEQUENCE

3T, 3D chemical-shift-encoded multi-gradient-echo, T1WI, T2WI, T2_STIR.

ASSESSMENT

BM FF and R2* values were assessed by manually drawing regions of interest at the L3, L4, ilium, and 1 cm below the bilateral trochanter of the femur (upper femur).

STATISTICAL TESTS

Independent sample t-tests, variance analysis, Spearman correlation.

RESULTS

BM FF and R2* at L3, L4, ilium, and upper femur, FFtotal and R2*total were significantly lower in the AL than control group. BM FF did not significantly differ between ALL and AML groups (PL3  = 0.060, PL4  = 0.086, Pilium  = 0.179, Pupper femur  = 0.149, and Ptotle  = 0.097, respectively). The R2* was significantly lower in ALL group than AML group for L3, L4, and R2*total . BM FF was moderately positively correlated with R2* in ALL group, and strongly positively correlated in AML group. Area under the receiver operating characteristic curves showed that BM FF had higher AUC in AL, ALL, and AML (all AUC = 1.000) than R2* (0.976, 0.996, and 0.941, respectively).

DATA CONCLUSION

MGRE-MRI mapping can be applied to measure BM FF and R2* values, and help evaluate BM infiltration and iron storage in children with AL.

EVIDENCE LEVEL

1 Technical Efficacy: 2.

MR Imaging Appearance of Ruptured Rathke Cleft Cyst and Associated Bone Marrow Enhancement

Rathke cleft cysts are common cystic pituitary lesions seen on MR imaging. A subset of Rathke cleft cysts can rupture within the sella and are uncommon. The imaging appearance of a ruptured Rathke cleft cyst has been previously described with nonspecific imaging findings. We present 7 cases of ruptured Rathke cleft cysts and basisphenoid bone marrow enhancement below the sella that could be used to potentially distinguish a ruptured Rathke cleft cyst from other cystic lesions.

Quantitative bone marrow lesion, meniscus, and synovitis measurement: current status

Imaging plays a pivotal role in osteoarthritis research, particularly in epidemiological and clinical trials of knee osteoarthritis (KOA), with the ultimate goal being the development of an effective drug treatment for future prevention or cessation of disease. Imaging assessment methods can be semi-quantitative, quantitative, or a combination, with quantitative methods usually relying on software to assist. The software generally attempts image segmentation (outlining of relevant structures). New techniques using artificial intelligence (AI) or deep learning (DL) are currently a frequent topic of research. This review article provides an overview of the literature to date, focusing primarily on the current status of quantitative software-based assessment techniques of KOA using magnetic resonance (MR) imaging. We will concentrate on the imaging evaluation of three specific structural imaging biomarkers: bone marrow lesions (BMLs), meniscus, and synovitis consisting of effusion synovitis (ES) and Hoffa's synovitis (HS). A brief clinical and imaging background review of osteoarthritis evaluation, particularly relating to these three structural markers, is provided as well as a general summary of the software methods. A summary of the literature with respect to each KOA assessment method will be presented overall as well as with respect to each specific biomarker individually. Novel techniques, as well as future goals and directions using quantitative imaging assessment, will be discussed.

Performance of baseline FDG-PET/CT radiomics for prediction of bone marrow minimal residual disease status in the LyMa-101 trial

The prognostic value of 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) at baseline or the predictive value of minimal residual disease (MRD) detection appear as potential tools to improve mantle cell lymphoma (MCL) patients' management. The LyMa-101, a phase 2 trial of the LYSA group (ClinicalTrials.gov:NCT02896582) reported induction therapy with obinutuzumab, a CD20 monoclonal antibody. Herein, we investigated the added prognostic value of radiomic features (RF) derived from FDG-PET/CT at diagnosis for MRD value prediction. FDG-PET/CT of 59 MCL patients included in the LyMa-101 trial have been independently, blindly and centrally reviewed. RF were extracted from the disease area with the highest uptake and from the total metabolic tumor volume (TMTV). Two models of machine learning were used to compare several combinations for prediction of MRD before autologous stem cell transplant consolidation (ASCT). Each algorithm was generated with or without constrained feature selections for clinical and laboratory parameters. Both algorithms showed better discrimination performances for negative vs positive MRD in the lesion with the highest uptake than in the TMTV. The constrained use of clinical and biological features showed a clear loss in sensitivity for the prediction of MRD status before ASCT, regardless of the machine learning model. These data plead for the importance of FDG-PET/CT RF compared to clinical and laboratory parameters and also reinforced the previously made hypothesis that the prognosis of the disease in MCL patients is linked to the most aggressive contingent, within the lesion with the highest uptake.