Variable Clinical Courses of Varicella Zoster Virus Infection-related or Vaccination-related Bone Marrow Failure.

We report 5 children with bone marrow failure (BMF) after primary varicella zoster virus (VZV) infection or VZV vaccination, highlighting the highly variable course. Two patients were treated with intravenous immunoglobulins; one had a slow hematologic recovery, and the other was rescued by allogeneic hematopoietic stem cell transplantation (HSCT). Of the 2 patients treated with immunosuppressive therapy with antithymocyte globulin and cyclosporine, one had a complete response, and the other was transplanted for nonresponse. One patient underwent a primary allograft. All patients are alive. This study demonstrated that VZV-associated BMF is a life-threatening disorder that often requires HSCT.

Bone marrow edema of the knee: a narrative review.

Bone marrow edema (BME) is a frequent MRI finding in patients with knee pain. According to the etiology, BME of the knee can be classified into three main categories: ischemic, mechanic, and reactive. The diagnosis may be difficult, because of the specificity of symptoms and the poor radiographic findings. MRI is the gold standard, showing an area of altered signal of the bone with an high signal intensity on fat-suppressed, T2 weighted images, usually in combination with an intermediate or low signal intensity on T1 weighted images. Bone marrow edema tends to be self-limiting and, in most cases, resolves without any consequences in a varying amount of time. However, since it may evolve to complete joint destruction, early diagnosis and correct treatment are crucial to prevent the articular degeneration. Conservative therapy is the first step, with no weight-bearing for 3 to 6 weeks on the affected side, in combination with the administration of anti-inflammatory drugs or painkillers to manage symptoms. In non-responding forms and more advanced stages, minimally invasive preservative surgery can provide significant results, with subchondroplasty and core decompression being the two main procedures available. Knee arthroplasty, both total (TKA) or unicompartmental (UKA), is the only effective option when the degradation of cartilage is diffuse and in patients with subchondral bone collapse.

Prediction of radiographic progression during a treat-to-target strategy by the sequential application of MRI-proven bone marrow oedema and power-Doppler grade ≥2 articular synovitis in rheumatoid arthritis: Retrospective observational study.

OBJECTIVES: To investigate the appropriate timing, useful findings and combination of magnetic resonance imaging (MRI) and ultrasound (US) for predicting the radiographic progression in early rheumatoid arthritis (RA). METHODS: Forty-four active RA patients, who examined by both of MRI and US in the symptomatic wrist and finger joints, were recruited in Nagasaki University Hospital from 2010 to 2017 and treated by the treat-to-target therapeutic strategy for 1 year. MRI was evaluated by RA MRI scoring and US by Outcomes Measures in Rheumatology Clinical Trial, respectively. Plain radiographs were assessed by the Genant-modified Sharp score for the symptomatic side in the same manner as MRI and US. Radiographic progression was defined as an annual increase ≥0.75 at 1 year. Factors associated with radiographic progression were analysed. Also, the optimal combination of MRI and US at each timepoint was considered. RESULTS: Logistic regression model revealed that MRI-proven bone marrow oedema at baseline and 6 months and joint counts of power-Doppler grade ≥2 articular synovitis at 3 or 6 months were significantly associated with radiographic progression at 1 year. CONCLUSION: This study may suggest the favourable timing and combination of MRI and US at each point to predict radiographic progression in patients with early-stage RA.

Quantification of bone marrow oedema and fat metaplasia in sacroiliac joints in spondyloarthritis patients using histographic magnetic resonance imaging analysis.

OBJECTIVES: To demonstrate a possible basis for a quantitative magnetic resonance imaging (MRI) approach that uses histographic analysis to determine bone marrow oedema (BME) and fat metaplasia at sacroiliac joints (SIJs) level in patients with axial spondyloarthritis (axSpA). METHODS: In this prospective, cross-sectional study, consecutive axSpA patients with inflammatory low back pain underwent 1.5-T MRI. MRI images were scored on a 4-point (0-3) scoring system both for BME and fat metaplasia by two radiologists. A region-of-interest based histographic quantitative analysis was used to assess MRI images. Using the area under the receiver operating characteristic curve (AUC-ROC) approach was tested the diagnostic accuracy of histographic analysis for detecting BME vs. BME and fat metaplasia on MRI images. RESULTS: 17 of the 43 patients (39.5%) included only had a BME lesion, while the remaining 26 patients (60.5%) had both BME and fat metaplasia at the SIJ level. Inter-rater agreement between readers was good (weighted kappa 0.643). On MRI images, BME and BME+fat metaplasia showed significant difference in histographic analysis (p<0.001), with an AUC-ROC of 0.898, and an optimal cut-off point of 311 at histographic analysis in the distinction of BME vs. fat metaplasia. CONCLUSIONS: Histographic analysis could represent a method for quantifying BME on MRI images of SIJs in patients with axSpA. This type analysis can provide important prognostic information and guide the choice of treatment in patients with sacroiliitis.

Dual-energy CT in sacral fragility fractures: defining a cut-off Hounsfield unit value for the presence of traumatic bone marrow edema in patients with osteoporosis.

BACKGROUND: Demographic change entails an increasing incidence of fragility fractures. Dual-energy CT (DECT) with virtual non-calcium (VNCa) reconstructions has been introduced as a promising diagnostic method for evaluating bone microarchitecture and marrow simultaneously. This study aims to define the most accurate cut-off value in Hounsfield units (HU) for discriminating the presence and absence of bone marrow edema (BME) in sacral fragility fractures. METHODS: Forty-six patients (40 women, 6 men; 79.7 ± 9.2 years) with suspected fragility fractures of the sacrum underwent both DECT (90 kVp / 150 kVp with tin prefiltration) and MRI. Nine regions-of-interest were placed in each sacrum on DECT-VNCa images. The resulting 414 HU measurements were stratified into "edema" (n = 80) and "no edema" groups (n = 334) based on reference BME detection in T2-weighted MRI sequences. Area under the receiver operating characteristic curve was calculated to determine the desired cut-off value and an associated conspicuity range for edema detection. RESULTS: The mean density within the "edema" group of measurements (+ 3.1 ± 8.3 HU) was substantially higher compared to the "no edema" group (-51.7 ± 21.8 HU; p < 0.010). Analysis in DECT-VNCa images suggested a cut-off value of -12.9 HU that enabled sensitivity and specificity of 100% for BME detection compared to MRI. A range of HU values between -14.0 and + 20.0 is considered indicative of BME in the sacrum. CONCLUSIONS: Quantitative analysis of DECT-VNCa with a cut-off of -12.9 HU allows for excellent diagnostic accuracy in the assessment of sacral fragility fractures with associated BME. A diagnostic "one-stop-shop" approach without additional MRI is feasible.

Increased Ripk1-mediated bone marrow necroptosis leads to myelodysplasia and bone marrow failure in mice.

Hematopoiesis is a dynamic system that requires balanced cell division, differentiation, and death. The 2 major modes of programmed cell death, apoptosis and necroptosis, share molecular machinery but diverge in outcome with important implications for the microenvironment; apoptotic cells are removed in an immune silent process, whereas necroptotic cells leak cellular contents that incite inflammation. Given the importance of cytokine-directed cues for hematopoietic cell survival and differentiation, the impact on hematopoietic homeostasis of biasing cell death fate to necroptosis is substantial and poorly understood. Here, we present a mouse model with increased bone marrow necroptosis. Deletion of the proapoptotic Bcl-2 family members Bax and Bak inhibits bone marrow apoptosis. Further deletion of the BH3-only member Bid (to generate Vav CreBaxBakBid triple-knockout [TKO] mice) leads to unrestrained bone marrow necroptosis driven by increased Rip1 kinase (Ripk1). TKO mice display loss of progenitor cells, leading to increased cytokine production and increased stem cell proliferation and exhaustion and culminating in bone marrow failure. Genetically restoring Ripk1 to wild-type levels restores peripheral red cell counts as well as normal cytokine production. TKO bone marrow is hypercellular with abnormal differentiation, resembling the human disorder myelodysplastic syndrome (MDS), and we demonstrate increased necroptosis in MDS bone marrow. Finally, we show that Bid impacts necroptotic signaling through modulation of caspase-8-mediated Ripk1 degradation. Thus, we demonstrate that dysregulated necroptosis in hematopoiesis promotes bone marrow progenitor cell death that incites inflammation, impairs hematopoietic stem cells, and recapitulates the salient features of the bone marrow failure disorder MDS.

Bone marrow necrosis in pediatric malignancies: 10-Year retrospective review and review of literature.

Bone marrow necrosis (BMN) is a rare pathologic finding, but when encountered is most often associated with malignancy. In adults, its presence correlates with an inferior prognosis, however in children the prognostic implication is unclear. We performed a retrospective review of 3,760 bone marrow specimens in patients ≤18 years over a 10-year period. BMN was identified in less than 1% of specimens and only in patients with leukemia, lymphoma, or neuroblastoma. BMN contributed to a delay in diagnosis; however, advanced medical imaging may serve as a tool to localize nonnecrotic areas for bone marrow sampling, facilitating an expedited diagnosis.

Postoperative bone marrow edema lasts no more than 6 months after uncomplicated arthroscopic double-row rotator cuff repair with PEEK anchors.

PURPOSE: To assess the natural evolution of the osseous reaction following arthroscopic double-row rotator cuff repair with PEEK anchors and to analyze its correlation with clinical shoulder function. METHODS: Between 2015 and 2017, 159 patients received arthroscopic double-row rotator cuff repair with PEEK anchors and underwent serial clinical and radiological follow-up (3, 6, 12, and 24 months). Radiological results were analyzed by tendon integrity, bone marrow edema, and peri-implant osteolysis. Clinical shoulder function was evaluated with the Constant score. RESULTS: One-hundred and seventeen patients were enrolled; among them, 63% demonstrated bone marrow edema around the anchors on postoperative 3-month MRI. The edema area percentage was 41% ± 7%. At 6 months, edema was only seen in 12% of cases, with an area percentage of 18% ± 5%. At 12 and 24 months, edema was rarely present. Fluid signals around the anchor were observed in 17.6%, 42.7%, 33.3%, and 21.0% of patients at 3, 6, 12, and 24 months, respectively; the tunnel widening values were 1.1 ± 0.4 mm, 1.8 ± 0.5 mm, 2.3 ± 0.6 mm, and 2.2 ± 0.7 mm at each follow-up, respectively. The sign of osteolysis was significantly more obvious around the lateral anchor than around the medial anchor. The presence of an osseous reaction was not correlated with worse clinical outcome. CONCLUSION: Osseous reactions following arthroscopic rotator cuff repair are common and significant even with PEEK anchors. Bone marrow edema does not last more than 6 months in patients without complications. Peri-implant osteolysis is more evident around the lateral anchor than around the medial anchor and improves gradually over time. The sign of osteolysis is not correlated with clinical shoulder function. Based on these findings, surgeons should be cautious about bone marrow edema lasting more than 6 months following arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: Level IV.

High prevalence of spondyloarthritis-like MRI lesions in postpartum women: a prospective analysis in relation to maternal, child and birth characteristics.

OBJECTIVES: Bone marrow oedema (BMO) on MRI of sacroiliac joints (SIJs) represents a hallmark of axial spondyloarthritis (SpA), yet such lesions may also occur under augmented mechanical stress in healthy subjects. We therefore sought to delineate the relationship between pregnancy/delivery and pelvic stress through a prospective study with repeated MRI. Results were matched with maternal, child and birth characteristics. METHODS: Thirty-five women underwent a baseline MRI-SIJ within the first 10 days after giving birth. MRI was repeated after 6 months and, if positive for sacroiliitis according to the Assessment of SpondyloArthritis International Society (ASAS) definition, after 12 months. BMO and structural lesions were scored by three trained readers using the Spondyloarthritis Research Consortium of Canada (SPARCC) method. RESULTS: Seventy-seven per cent of the subjects (27/35) displayed sacroiliac BMO immediately postpartum, 60% fulfilled the ASAS definition of a positive MRI. After 6 months, 46% of the subjects (15/33) still showed BMO, representing 15% (5/33) with a positive MRI. After 12 months, MRI was still positive in 12% of the subjects (4/33). Few structural lesions were detected. Intriguingly, in this study, the presence of BMO was related to a shorter duration of labour and lack of epidural anaesthesia. CONCLUSION: A surprisingly high prevalence of sacroiliac BMO occurs in women immediately postpartum. Our data reveal a need for a waiting period of at least 6 months to perform an MRI-SIJ in postpartum women with back pain. This study also underscores the importance of interpreting MRI-SIJ findings in the appropriate clinical context.

MRI of the sacroiliac joints in athletes: recognition of non-specific bone marrow oedema by semi-axial added to standard semi-coronal scans.

OBJECTIVE: Assessment of combined semi-axial and semi-coronal SI joint MRI in two cohorts of young athletes to explore frequency and topography of non-specific bone marrow oedema (BMO), its association with four constitutional SI joint features, and potential restriction of false-positive assignments of Assessment of SpondyloArthritis International Society-defined sacroiliitis on standard semi-coronal scans alone. METHODS: Combined semi-axial and semi-coronal SI joint MRI scans of 20 recreational runners before/after running and 22 elite ice-hockey players were evaluated by three blinded readers for BMO and its association with four constitutional SI joint features: vascular partial volume effect, deep iliac ligament insertion, fluid-filled bone cyst and lumbosacral transitional anomaly. Scans of TNF-treated spondyloarthritis patients served to mask readers. We analysed distribution and topography of BMO and SI joint features across eight anatomical SI joint regions (upper/lower ilium/sacrum, subdivided in anterior/posterior slices) descriptively, as concordantly recorded by ⩾2/3 readers on both MRI planes. BMO confirmed on both scans was compared with previous evaluation of semi-coronal MRI alone, which met the Assessment of SpondyloArthritis International Society definition for active sacroiliitis. RESULTS: Perpendicular semi-axial and semi-coronal MRI scans confirmed BMO in the SI joint of every fourth young athlete, preferentially in the anterior upper sacrum. BMO associated with four constitutional SI joint features was observed in 20-36% of athletes, clustering in the posterior lower ilium. The proportion of Assessment of SpondyloArthritis International Society-positive sacroiliitis recorded on the semi-coronal plane alone decreased by 33-56% upon amending semi-axial scans. CONCLUSION: Semi-axial combined with standard semi-coronal scans in MRI protocols for sacroiliitis facilitated recognition of non-specific BMO, which clustered in posterior lower ilium/anterior upper sacrum.

Allopurinol use during pediatric acute lymphoblastic leukemia maintenance therapy safely corrects skewed 6-mercaptopurine metabolism, improving inadequate myelosuppression and reducing gastrointestinal toxicity.

BACKGROUND: Inadequate myelosuppression during maintenance therapy for acute lymphoblastic leukemia (ALL) is associated with an increased risk of relapse. One mechanism is skewed metabolism of 6-mercaptopurine (6MP), a major component of maintenance therapy, which results in preferential formation of the hepatotoxic metabolite (6-methyl mercaptopurine [6MMP]) with low levels of the antileukemic metabolite, 6-thioguanine nucleotides (6TGN). Allopurinol can modify 6MP metabolism to favor 6TGN production and reduce 6MMP. METHODS: Patients in maintenance were considered for allopurinol treatment who had the following features: (a) Grade ≥3 hepatotoxicity; (b) Grade ≥2 nonhepatic gastrointestinal (GI) toxicity; or (c) persistently elevated absolute neutrophil count (ANC) despite >150% protocol dosing of oral chemotherapy. RESULTS: From 2013 to 2017, 13 ALL patients received allopurinol: nine for hepatotoxicity, five for inadequate myelosuppression, and three for nonhepatic GI toxicity (four met multiple criteria). Allopurinol was well tolerated, without significant adverse events. Allopurinol resulted in a significant decrease in the average 6MMP/6TGN ratio (mean reduction 89.1, P = .0001), with a significant increase in 6TGN (mean 550.4, P = .0008) and a significant decrease in 6MMP (mean 13 755, P = .0013). Patients with hepatotoxicity had a significant decrease in transaminase elevation after starting allopurinol (alanine transaminase [ALT] mean decrease 22.1%, P = .02), and all with nonhepatic GI toxicity had improved symptoms. Those with inadequate myelosuppression had a significant increase in the time with ANC in goal (mean increase 26.4%, P = .0004). CONCLUSIONS: Allopurinol during ALL maintenance chemotherapy is a safe, feasible, and effective intervention for those who have altered metabolism of 6MP causing toxicity or inadequate myelosuppression.

Predicting Bone Marrow Edema and Fracture Age in Vertebral Fragility Fractures Using MDCT.

OBJECTIVE. The purpose of this study was to evaluate whether CT features can predict bone marrow edema (BME) on MRI and fracture age in vertebral fragility fractures. MATERIALS AND METHODS. A total of 189 thoracolumbar compression fractures in 103 patients (14 men, 89 women; mean age, 76 years) imaged with both spine CT and MRI were retrospectively included. The presence and extent of BME were assessed on MRI to divide fractures into those with and without BME. The group with BME was then classified for subgroup analysis into fractures with extensive BME (comprising 50% or more of the vertebral body) and those with BME comprising less than 50% of the vertebral body. On CT, five features (presence of cortical or endplate fracture line, presence of trabecular fracture line, presence of condensation band, change in trabecular attenuation, and width of paravertebral soft-tissue change) were analyzed. RESULTS. All five CT findings were predominantly seen in fractures with BME (p < 0.001). Elevated trabecular attenuation, presence of a cortical or endplate fracture line, and paravertebral soft-tissue width showed excellent diagnostic indication for fractures with BME (ROC AUCs: 0.990, 0.976, and 0.950, respectively). In the subgroup with extensive BME, paravertebral soft-tissue width was significantly higher, whereas the change in trabecular attenuation was lower compared with those with BME comprising less than 50% of the vertebral body (p < 0.001). When BME was present, fracture age was not significantly different between the two subgroups, and only greater trabecular attenuation elevation was predictive of older fracture age on linear mixed model analyses (p < 0.001). Interobserver agreement was good for the trabecular fracture line factor and excellent for all other factors. CONCLUSION. CT features accurately correlate with the presence and extent of BME in vertebral fragility fractures. Elevation of trabecular attenuation was the only significant image predictor of fracture age.

The semi-automated algorithm for the detection of bone marrow oedema lesions in patients with axial spondyloarthritis.

The aim of the study was to create the efficient tool for semi-automated detection of bone marrow oedema lesions in patients with axial spondyloarthritis (axSpA). MRI examinations of 22 sacroiliac joints of patients with confirmed axSpA-related sacroiliitis (median SPARCC score: 14 points) were included into the study. Design of our algorithm is based on Maksymowych et al. evaluation method and consists of the following steps: manual segmentation of bones (T1W sequence), automated detection of reference signal region, sacroiliac joint central lines and ROIs, a division of ROIs into quadrants, automated detection of inflammatory changes (STIR sequence). As a gold standard, two sets of manual lesion delineations were created. Two approaches to the performance assessment of lesion detection were considered: pixel-wise (detections compared pixel by pixel) and quadrant-wise (quadrant to quadrant). Statistical analysis was performed using Spearman's correlation coefficient. Correlation coefficient obtained for pixel-wise comparison of semi-automated and manual detections was 0.87 (p = 0.001), while for quadrant-wise analysis was 0.83 (p = 0.001). The correlation between two sets of manual detections was 0.91 for pixel-wise comparison (p = 0.001) and 0.88 (p = 0.001) for quadrant-wise approach. Spearman's correlation between two manual assessments was not statistically different from the correlation between semi-automated and manual evaluations, both for pixel- (p = 0.14) and quadrant-wise (p = 0.17) analysis. Average single slice processing time: 0.64 ± 0.30 s. Our method allows for objective detection of bone marrow oedema lesions in patients with axSpA. The quantification of affected pixels and quadrants has comparable reliability to manual assessment.

Ongoing MRI remodeling 3-7 years after collagen meniscus implantation in stable knees.

PURPOSE: The purpose of the present study was to evaluate the clinical and radiological 3-7 years outcomes of patients who underwent collagen meniscus implantation in stable or stabilized knees. It was the hypothesis that using the collagen meniscus (CMI) good clinical 3-7 years outcomes with low pain levels are achieved. METHODS: Thirty-nine patients (male:female = 30:9, mean age 34 ± 10 years) underwent arthroscopic CMI after subtotal medial (n = 32) or lateral meniscectomy (n = 7). A 7-mm CMI was performed due to prophylactic (n = 25) or therapeutic indication (n = 14). IKDC score, Tegner score preinjury, preoperatively and at follow-up, Lysholm score and visual analogue scale for pain and satisfaction (follow-up rate 90%) were assessed. MRI scans were analyzed according to the Genovese criteria (n = 19). Implant failure was defined as infection or mechanical failure of the device. The minimum follow-up time was 36 months (range 36-84 months). RESULTS: The mean VAS satisfaction preoperatively and at follow-up was 4.0 ± 0 and 1.6 ± 1.0. The mean VAS pain was 4.3 ± 3.2 preoperatively and at last follow-up 2.1 ± 1.7. The median Tegner score preinjury was 7 (range 3-10), it decreased preoperatively to median 3.5 (range 1-8) and nearly reached the preinjury level at last follow-up 6 (range 3-10). The mean Lysholm score before surgery was 66 ± 20 and 91 ± 8 at last follow-up. Seven patients (38.9%) had a normal total IKDC score (A), 10 patients were nearly normal (B) and 1 patient slightly abnormal (C). In MRI the CMI was entirely resorbed in 4 patients (21%) and partially resorbed in 15 (79%). In 4 patients (21%) the CMI was isointense, in 14 (74%) slightly hyperintense and in 1 (5%) highly hyperintense. Ten patients (53%) showed marked signs of bone marrow edema. In 13 patients (68%) an extrusion of the meniscus > 3 mm at last follow-up was found. CONCLUSIONS: Meniscal substitution with the CMI showed good to excellent clinical 3-7 results. The CMI shows an ongoing remodelling with decreased signal intensity and decreased size. However, as meniscus extrusion remained at the same level and bone marrow edema decreased from 1 year to longer term follow-up, it appears that the remodeling comes to an end at about 5 years after CMI. LEVEL OF EVIDENCE: IV.

[Bone marrow serous degeneration complicating acute leukemia]. / Transformation gélatineuse de la moelle osseuse au cours d'une leucémie aiguë.

INTRODUCTION: Serous degeneration of bone marrow is a rare hematological complication, of multiple etiologies, which physiopathology is yet to be fully understood. It is described as a focal hypoplasia of the bone marrow and atrophy of its adipocytes coupled with an extracellular deposit of an eosinophilic substance that corresponds to "hyaluronic acid". The prognosis of these lesions depends on the etiological diagnosis. OBSERVATION: We report the case of a 19-year-old female patient without no notable pathological history, hospitalized in a regional hospital for mucocutaneous pallor with an impaired general condition. The biological assessment revealed a pancytopenia, and the presence of 60 % blast cells on the blood smear, which was in favor of acute leukemia. As part of the etiological assessment, a bone marrow biopsy was performed, revealing a typical aspect of serous degeneration. The bone marrow cellularity was reduced, made of rare hematopoietic cells, dissociated by pale extracellular deposits that were colored by PAS and alcian blue, with no individualized blasts. DISCUSSION: Serous transformation of the hematopoietic marrow is a rare condition, described at the end of the 19th century. The most severe forms are observed in young patients with hypoplasia. It most often manifests as pancytopenia at the beginning, if not then by an isolated cytopenia, anemia or thrombocytopenia. It is interesting to underline the contribution of MRI in diagnosis. The foci of bone marrow serous degeneration are characterized in the long bones by a fluid signal with a T1 hypo-signal and a T2 hyper-signal with no enhancement after injection of gadolinium, unlike bone metastases. The histology of bone marrow biopsy finds focal marrow hypoplasia of the hematopoietic lines associated with a depletion of adipocytes and an eosinophilic gelatinous interstitial infiltration alcian blue and PAS positive. The histological differential diagnosis is amyloidosis due to red Congo positivity, a previous biopsy (the absence of adipose tissue or hematopoietic tissue with granulation tissue and bone formation) and interstitial edema. Bone marrow necrosis can also be observed. Serous degeneration of bone marrow can be a symptom of a chronic systemic illness. In most cases, it is found in cases of severe chronic malnutrition, such as anorexia nervosa, certain cancers (acute leukemia), systemic diseases (lupus) or severe infection. Though there is no specific treatment for this complication, the treatment of the cause most often allows for the complete regression of the peripheral and spinal anomalies. CONCLUSION: In rare cases, as is the case in our observation, the serous degeneration of bone marrow can reveal underlying solid tumors or hemopathies, knowledge of it can help guide the investigations towards these etiologies.

Is active sacroiliitis on MRI associated with radiographic damage in axial spondyloarthritis? Real-life data from the ASAS and DESIR cohorts.

OBJECTIVE: To assess any association between bone marrow oedema on MRI of the sacroiliac joints (MRI-SIJ) according to local readings in daily practice and the development of structural damage on radiographs of the SIJ (X-SIJ) in axial spondyloarthritis (axSpA). METHODS: Patients with axSpA from the Assessment of the SpondyloArthritis international Society (ASAS) and DEvenir des Spondylarthopathies Indifférenciées Récentes (DESIR) multicentre cohorts were included. MRI-SIJ and X-SIJ were obtained at baseline, and X-SIJ at follow-up after a mean 4.6 years (ASAS) and 5.1 years (DESIR). All images were scored by local readers. Structural damage in the X-SIJ was defined according to the modified New York criteria. The percentage of structural net progression (number of 'progressors' minus the number of 'regressors' divided by the total number of patients) was assessed and the effect of bone marrow oedema on MRI-SIJ on X-SIJ damage evaluated by multivariable logistic regression. RESULTS: In total, 125 (ASAS-cohort) and 415 (DESIR-cohort) patients had baseline MRI-SIJ and complete X-SIJ data available. According to local readings, progression and 'improvement' in X-SIJ was seen in both the ASAS- and DESIR-cohort, yielding a net progression that was higher in the former than in the latter (19.2% and 6.3%). In multivariable analysis, baseline bone marrow oedema on MRI-SIJ was strongly associated with X-SIJ structural progression in both ASAS (odds ratio = 3.2 [95% CI: 1.3; 7.9]), and DESIR (odds ratio = 7.6 [95% CI: 4.3; 13.2]). CONCLUSION: Inflammation on MRI-SIJ is associated with future radiographic progression according to local readings despite an expected increased imprecision invoked by local readings.

Single-source dual-energy computed tomography for the assessment of bone marrow oedema in vertebral compression fractures: a prospective diagnostic accuracy study.

OBJECTIVES: To evaluate the diagnostic accuracy of single-source dual-energy computed tomography (DECT) for the detection of bone marrow oedema (BME) in patients with vertebral compression fractures. METHODS: Patients over 50 years of age with radiographically suspected vertebral compression fracture of the thoracic or lumbar spine were prospectively enrolled. All patients underwent DECT with sequential acquisition of 80 and 135 kVp datasets on a 320-row detector CT scanner and 1.5-Tesla magnetic resonance imaging (MRI) including T1-weighted and short-tau inversion recovery (STIR) sequences. Virtual non-calcium (VNCa) images were reconstructed using a three-material decomposition algorithm. Vertebrae with height loss in CT were scored for the presence of BME in both MRI and DECT and used to determine signal- and contrast-to-noise ratios (SNR and CNR). Contingency analysis using MRI as standard of reference and Fleiss's kappa were calculated. IRB approval was obtained. RESULTS: In total 192 vertebral compression fractures in 70 patients (23 men, 47 women; mean age 70.7 years (SD 9.8)) were included in our analysis. DECT showed a reader-dependent sensitivity of 72% and specificity of 70% for BME. Fleiss's kappa was .40 for DECT and .58 for MRI. T1-weighted images had significantly better SNR and CNR compared to STIR, CT, and VNCa (p < .0001); however, there was no difference between STIR and VNCa. CONCLUSIONS: VNCa images depict BME with adequate sensitivity and specificity and can be acquired on a single-source system. Image quality is adequate but trained readers are needed for image interpretation. KEY POINTS: • Dual-energy CT in a single-source technique can help to detect bone marrow oedema in patients with vertebral compression fractures. • However, given the inferior inter-rater reliability and limited specificity compared to MRI, experienced readers are needed for image interpretation. • Dual-energy CT of the spine has limited sensitivity for the detection of bone marrow oedema in vertebra with previous surgical intervention.

Outcome of haematopoietic stem cell transplantation in dyskeratosis congenita.

Dyskeratosis congenita (DC) is a genetic multisystem disorder with frequent involvement of the bone marrow. Haematopoietic stem cell transplantation (HSCT) is the only definitive cure to restore haematopoiesis, even though it cannot correct other organ dysfunctions. We collected data on the outcome of HSCT in the largest cohort of DC (n = 94) patients ever studied. Overall survival (OS) and event-free survival (EFS) at 3 years after HSCT were 66% and 62%, respectively. Multivariate analysis showed better outcomes in patients aged less than 20 years and in patients transplanted from a matched, rather than a mismatched, donor. OS and EFS curves tended to decline over time. Early lethal events were infections, whereas organ damage and secondary malignancies appeared afterwards, even a decade after HSCT. A non-myeloablative conditioning regimen appeared to be most advisable. Organ impairment present before HSCT seemed to favour the development of chronic graft-versus-host disease and T-B immune deficiency appeared to enhance pulmonary fibrosis. According to the present data, HSCT in DC is indicated in cases of progressive marrow failure, whereas in patients with pre-existing organ damage, this should be carefully evaluated. Further efforts to investigate treatment alternatives to HSCT should be encouraged.

Effect of mechanical stress on magnetic resonance imaging of the sacroiliac joints: assessment of military recruits by magnetic resonance imaging study.

Objective: To assess the baseline condition of the SI joints (SIJs) in healthy individuals without symptoms of back pain and to study the effect of mechanical stress caused by intense physical training on MRI of the SIJs. Methods: Twenty-two military recruits underwent an MRI of the SIJs before and after 6 weeks of intense standardized physical training. Bone marrow oedema and structural lesions were scored based on the Spondyloarthritis Research Consortium of Canada (SPARCC) method, by three trained readers blinded for time sequence and clinical findings. Additionally, fulfilment of the Assessment of SpondyloArthritis international Society (ASAS) definition of a positive MRI was evaluated. Results: At baseline, 9/22 recruits (40.9%) already presented a SPARCC score ⩾1; this number increased to 11/22 (50.0%) at week 6 (P = 0.625). In these patients, the mean (SD) SPARCC score was 2.4 (0.4) at baseline, compared to 3.7 (1.3) at week 6. Overall, the mean (SD) change in SPARCC score over time in all 22 patients was 0.9 (0.6) (P = 0.109). A positive MRI according to the ASAS definition was present in 5/22 recruits (22.7%) at baseline, which increased to 8/22 (36.4%) at follow-up (P = 0.375). Structural lesions were present in 6/22 subjects (27.3%), both at baseline and after 6 weeks of training. Conclusion: A substantial proportion of healthy active individuals without any symptoms of back pain displayed bone marrow oedema lesions on MRI at baseline. However, MRI lesions did not increase significantly after 6 weeks of intensive physical training. Our study underscores the necessity to interpret MRI findings of the SIJs in the appropriate clinical context, even in a young active population.

Bone marrow failure and extramedullary hematopoiesis in McCune-Albright syndrome.

In fibrous dysplasia/McCune-Albright syndrome (FD/MAS), bone and bone marrow are, to varying degrees, replaced by fibro-osseous tissue typically devoid of hematopoietic marrow. Despite the extensive marrow replacement in severely affected patients, bone marrow failure is not commonly associated with FD/MAS. We present a 14-year-old girl with FD/MAS, who developed pancytopenia and extramedullary hematopoiesis (EMH) with no identified cause, in the setting of iatrogenic thyrotoxicosis and hyperparathyroidism. Pancytopenia, requiring monthly blood transfusions, persisted despite multiple strategies to correct these endocrinopathies. Due to worsening painful splenomegaly, likely as a result of sequestration, splenectomy was performed. Following splenectomy, pancytopenia resolved and patient has since been transfusion-independent. We report the first detailed case of bone marrow failure and EMH in FD/MAS. The etiology of marrow failure is likely multifactorial and related to the loss of marrow reserve due to extensive polyostotic FD, exacerbated by iatrogenic thyrotoxicosis and hyperparathyroidism. Mini Abstract: A patient with fibrous dysplasia developed bone marrow failure and extramedullary hematopoiesis. The etiology likely involved loss of hematopoetic marrow space and uncontrolled endocrinopathies. Splenectomy was therapeutic.