Radiological follow-up of osteonecrosis lesions in children and adolescents with Hodgkin lymphoma.

Osteonecrosis (ON) is a common complication of glucocorticoid-based Hodgkin lymphoma (HL) treatment, but the natural evolution and prognosis of ON lesions remain poorly understood. We describe the radiological evolution of ON lesions identified in a Nordic population-based cohort of paediatric HL patients. Magnetic resonance images of suspected ON lesions were centrally reviewed to confirm ON diagnosis and grade the ON lesions according to the Niinimäki classification. The study included 202 ON lesions in 46 patients, of which 77 were joint lesions. Follow-up images were available for 146/202 lesions, with a mean follow-up time of 28 months. During follow-up, 71% of the lesions remained stable, 26% improved or resolved, and 3% progressed. A higher ON grade at diagnosis was associated with a lower likelihood of spontaneous resolution. The likelihood for resolution of ON decreased by 50% for each year of added patient age, when adjusted for sex, ON location, and symptoms. Hip ON showed less spontaneous improvement compared with other joints, and the risk for surgery was 13-fold in hip ON. Grades 3-4 joint ON has the potential to either progress or resolve, warranting follow-up in patients with severe symptoms. Research on secondary prevention should be directed at grade 3-4 joint ON.

Symptomatic osteonecrosis in children treated for Hodgkin lymphoma: A population-based study in Sweden, Finland, and Denmark.

BACKGROUND: Osteonecrosis (ON) is a potentially disabling skeletal complication of cancer treatment. Although symptomatic osteonecrosis (sON) is well-known in acute lymphoblastic leukemia (ALL), with an incidence around 6%, studies on sON in pediatric Hodgkin lymphoma (HL) are scarce. The aim of this study was to examine the incidence, risk factors, and outcome of sON in children treated for HL. PROCEDURE: A total of 490 children under 18, diagnosed with HL between 2005 and 2019 in Sweden, Finland, and Denmark were eligible for the study. Data on patient characteristics, HL treatment, and development of sON were collected from patients' medical records. Magnetic resonance imaging scans were used to establish ON diagnosis and grade ON according to the Niinimäki grading system. RESULTS: Cumulative 2-year incidence of sON among the 489 included patients was 5.5% (n = 30). The risk for developing sON was higher for those with older age (odds ratio [OR] 1.25, 95% confidence interval [CI]: 1.05-1.49, p < .010), female sex (OR 4.45, CI 1.87-10.58, p < .001), high total cumulative glucocorticoid (GC) doses (OR 1.76, 95% CI: 1.21-2.56, p = 0.003), and advanced HL (OR 2.19, 95% CI: 1.03-4.65, p = .042). Four (13.3%) patients underwent major surgical procedures and 13 (43.3%) had persistent symptoms due to ON at follow-up. CONCLUSIONS: This study shows that sON is as common in pediatric HL as in pediatric ALL, with risk factors such as older age, female sex, high cumulative GC doses, and advanced HL. Future HL protocol development should aim to reduce the burden of ON by modifying GC treatment.

Postmortem magnetic resonance imaging vs autopsy of second trimester fetuses terminated due to anomalies.

INTRODUCTION: Our aim was to investigate the accuracy of postmortem fetal magnetic resonance imaging (MRI) compared with fetal autopsy in second trimester pregnancies terminated due to fetal anomalies. A secondary aim was to compare the MRI evaluations of two senior radiologists. MATERIAL AND METHODS: This was a prospective study including 34 fetuses from pregnancies terminated in the second trimester due to fetal anomalies. All women accepted a postmortem MRI and an autopsy of the fetus. Two senior radiologists performed independent evaluations of the MRI images. A senior pathologist performed the fetal autopsies. The degree of concordance between the MRI evaluations and the autopsy reports was estimated as well as the consensus between the radiologists. RESULTS: Thirty-four fetuses were evaluated. Sixteen cases were associated with the central nervous system (CNS), five were musculoskeletal, one cardiovascular, one was associated with the urinary tract, and 11 cases had miscellaneous anomalies such as chromosomal aberrations, infections and syndromes. In the 16 cases related to the CNS, both radiologists reported all or some, including the most clinically significant anomalies in 15 (94%; CI 70%-100%) cases. In the 18 non-CNS cases, both radiologists reported all or some, including the most clinically significant anomalies in six (33%; CI 5%-85%) cases. In 21 cases (62%; CI 44%-78%), both radiologists held opinions that were consistent with the autopsy reports. The degree of agreement between the radiologists was high, with a Cohen's Kappa of 0.87. CONCLUSIONS: Postmortem fetal MRI can replace autopsy for second trimester fetuses with CNS anomalies. For non-CNS anomalies, the concordance is lower but postmortem MRI can still be of value when autopsy is not an option.

Agreement of radiographic measurements and patient-reported outcome in 61 patients with Legg-Calvé-Perthes disease at mean follow-up of 28 years.

It is unclear how patient-reported outcome in patients with Legg-Calvé-Perthes disease (LCPD) is correlated with radiographic outcome. It was therefore the aim of our long-term follow-up to evaluate the agreement of patient-reported outcome measures (PROM) with radiographic outcome in patients with a history of unilateral LCPD and a femoral head involvement of more than 50%. We further investigated to what extent the functional outcome (range of motion and Trendelenburg sign) correlates with PROM and radiographic outcome. At a mean follow-up of 28 years (15-42), 61 patients were investigated clinically and by plain radiography to evaluate the sphericity deviation score, femoral head enlargement and femoral neck growth inhibition. The patients also completed questionnaires for generic measures of health-related quality-of-life (ED-5D, EQ-visual analogue scale), the joint-specific Harris hip score and the nonarthritic hip score questionnaire. The radiographic measures sphericity deviation score, femoral head enlargement and femoral neck growth inhibition were strongly correlated with the joint-specific PROMs (Harris hip score and nonarthritic hip score) but not with EQ-5D and EQ-visual analogue scale. Inferior range of flexion and abduction and a positive Trendelenburg sign were associated with an inferior patient-reported outcome. Our findings highlight the importance of supporting femoral head re-modelling and containment and balancing trochanteric and femoral neck growth in patients with LCPD. To capture the whole picture of the outcome after LCPD, future studies should include a combination of radiographic measurements and joint-specific and generic outcome scores. Level of Evidence: Level III.

Ultrasmall iron oxide particle contrast agent and MRI can be used to monitor the effect of anti-rejection treatment.

BACKGROUND: The purpose of the study was to investigate the feasibility of monitoring anti-rejection treatment using a blood pool contrast agent and magnetic resonance (MR) imaging. METHODS: Allogeneic heterotopic heart transplantations in rats were performed. In one group (treated group), a mild acute rejection was developed and subsequently treated and MR imaging was performed before and after anti-rejection treatment. In the other group (nontreated group), a mild acute rejection was developed and allowed to progress without treatment and MR examinations were performed before and after the advance of the acute rejection. After injecting ultrasmall superparamagnetic contrast agent, the relative change of signal intensity (SI) over time was measured. The SI difference between both radiological investigations for every animal was calculated; hence, every animal served as its own control. RESULTS: In both treated and nontreated groups, a significant difference over time was found between the two MR examinations seen as a decrease in the treated group and an increase in the nontreatment group. CONCLUSION: It is concluded that the effect of anti-rejection treatment can be detected using a blood pool agent and MR imaging, as a change in SI corresponding to changes in the vascular permeability.

Acute cardiac transplant rejection: detection and grading with MR imaging with a blood pool contrast agent--experimental study in the rat.

PURPOSE: To investigate the possibility of detecting cardiac transplant rejection and determining its degree of severity with magnetic resonance (MR) imaging with a blood pool contrast agent. MATERIALS AND METHODS: Rat allogeneic (PVG to Wistar/Kyoto, n = 9) and syngeneic (Wistar/Kyoto to Wistar/Kyoto, n = 6) heterotopic heart transplantations were performed. On the 2nd and 6th postoperative days, an ultrasmall superparamagnetic iron oxide, or USPIO, contrast agent was injected intravenously at a dose of 2 mg of iron per kilogram of body weight. The injection was followed by three-dimensional T1-weighted MR imaging of the heart grafts with an imaging time of approximately 2 minutes for each image for 44 minutes. The signal intensity (SI) was measured in the myocardium over time, and the relative enhancement was calculated. After the 6th day, the rats were sacrificed, and the morphology of the transplanted hearts was assessed histologically. The CIs for the difference of the means on day 2 and day 6 were calculated by using a bootstrap technique, and the correlation between the relative SI change and the histologically determined degree of rejection were calculated with the Spearman rank order correlation coefficient. RESULTS: On day 6, a statistically significant difference between the groups was found at 4 minutes after injection of the contrast agent and increased with increasing time after injection. The mean percentage change in SI at the last time point for the allogeneic group on day 2 was -8.7% (SD, 8.5) and for the syngeneic group was -6.6% (SD, 6.0). On day 6, the allogeneic group had a relative SI change of 17.7% (SD, 8.7), whereas the syngeneic group had a change of -7.4% (SD, 2.6). There was a significant difference between only the two groups on day 6 (P <.001). Furthermore, in the allogeneic group the histologically determined degree of rejection correlated positively with the relative SI enhancement (r = 0.89, P <.005). CONCLUSION: Acutely rejecting heart transplants can be distinguished from nonrejecting ones in an animal model with MR imaging and a blood pool contrast agent. In addition, the relative SI enhancement reflects the histologically determined degree of rejection.