Background: While MRI is the primary diagnostic tool for the diagnosis of spondylodiscitis, the role of [¹⁸F]-fluorodeoxyglucose ([¹⁸F]FDG) PET/CT is gaining prominence. This study aimed to determine the frequency of [¹⁸F]FDG PET/CT usage and its impact on the in-hospital mortality rate in patients with spondylodiscitis, particularly in the geriatric population. Methods: We conducted a Germany-wide cross-sectional study from 2019 to 2021 using an open-access, Germany-wide database, analyzing cases with ICD-10 codes M46.2-, M46.3-, and M46.4- (‘Osteomyelitis of vertebrae’, ‘Infection of intervertebral disc (pyogenic)’, and ‘Discitis unspecified’). Diagnostic modalities were compared for their association with in-hospital mortality, with a focus on [¹⁸F]FDG PET/CT. Results: In total, 29,362 hospital admissions from 2019 to 2021 were analyzed. Of these, 60.1% were male and 39.9% were female, and 71.8% of the patients were aged 65 years and above. The overall in-hospital mortality rate was 6.5% for the entire cohort and 8.2% for the geriatric subgroup (p < 0.001). Contrast-enhanced (ce) MRI (48.1%) and native CT (39.4%) of the spine were the most frequently conducted diagnostic modalities. [¹⁸F]FDG PET/CT was performed in 2.7% of cases. CeCT was associated with increased in-hospital mortality (OR = 2.03, 95% CI: 1.90–2.17, p < 0.001). Cases with documented [¹⁸F]FDG PET/CT showed a lower frequency of in-hospital deaths (OR = 0.58, 95% CI: 0.18–0.50; p = 0.002). This finding was more pronounced in patients aged 65 and above (OR = 0.42, 95% CI: 0.27–0.65, p = 0.001). Conclusions: Despite its infrequent use, [¹⁸F]FDG PET/CT was associated with a lower in-hospital mortality rate in patients with spondylodiscitis, particularly in the geriatric cohort. This study is limited by only considering data on hospitalized patients and relying on the assumption of error-free coding. Further research is needed to optimize diagnostic approaches for spondylodiscitis.

To evaluate dual-source and split-beam filter multi-energy chest CT in assessing pulmonary perfusion on a lobar level in patients with lung emphysema, using perfusion SPECT as the reference standard. Patients with emphysema evaluated for lung volume reduction therapy between May 2016 and February 2021 were retrospectively included. All patients underwent SPECT and either dual-source or split-beam filter (SBF) multi-energy CT. To calculate the fractional lobar lung perfusion (FLLP), SPECT acquisitions were co-registered with chest CT scans (hereafter, SPECT/CT) and semi-manually segmented. For multi-energy CT scans, lung lobes were automatically segmented using a U-Net model. Segmentations were manually verified. The FLLP was derived from iodine maps computed from the multi-energy data. Statistical analysis included Pearson and intraclass correlation coefficients and Bland-Altman analysis. Fifty-nine patients (30 male, 29 female; 31 underwent dual-source CT, 28 underwent SBF CT; mean age for all patients, 67 years ± 8 [SD]) were included. Both multi-energy methods significantly correlated with the SPECT/CT acquisitions for all individual lobes (P < .001). Pearson correlation concerning all lobes combined was significantly better for dual-source (r = 0.88) than for SBF multi-energy CT (r = 0.78; P = .006). On the level of single lobes, Pearson correlation coefficient differed for the right upper lobe only (dual-source CT, r = 0.88; SBF CT, r = 0.58; P = .008). Dual-source and SBF multi-energy CT accurately assessed lung perfusion on a lobar level in patients with emphysema compared with SPECT/CT. The overall correlation was higher for dual-source multi-energy CT. Keywords: Chronic Obstructive Pulmonary Disease, Comparative Studies, Computer Applications, CT Spectral Imaging, Image Postprocessing, Lung, Pulmonary Perfusion © RSNA, 2023

Management of immunosuppression after solid organ transplantation in context of chimeric antigen receptor T-cell therapy (CART) is challenging. While required to prevent graft rejection, systemic immunosuppression can interfere with biological functions of apheresis products and adoptively transferred T cells. We treated a 33-year-old kidney transplant recipient who developed relapsed/refractory post-transplantation lymphoproliferative disorder (PTLD) with CD19-CART as a fourth-line therapy. Immunosuppression was discontinued before leukapheresis for CART and not re-initiated ever since. While the PTLD remained in complete remission, we did not observe any signs of graft rejection (clinically and by determination of donor-derived cell-free DNA) until last follow-up 23 months after CART. Phenotyping of peripheral blood immune cell subsets showed stable recovery of T- and B-cell compartments with dominant naïve differentiation. Immune responses against foreign antigens were shown by T-cell cytokine production after stimulation with virus-derived peptide pools and absence of Torque-Teno virus DNA. The lack of human leukocyte antigen antibodies and absence of T-cell proliferation in a mixed leukocyte reaction with peripheral blood cells of the kidney donor confirmed tolerance against donor antigens. We envision CD19-CART as a therapeutic option to prevent organ rejection without conventional long-term immunosuppression in selected patients.

Septic arthritis, although rare, is a critical joint-threatening emergency. The shoulder, being the third most common site after knee and hip joints, is predominantly affected by hematogenous spread of infection. F-18-FDG PET/CT has shown promise in identifying infectious foci and modifying treatment plans. This study aims to differentiate the metabolic patterns of septic shoulder arthritis from various stages of shoulder osteoarthritis using F-18-FDG PET/CT and assess its diagnostic performance. We retrospectively included subsequent patients diagnosed with septic shoulder arthritis between November 2017 and October 2023, who had undergone whole-body F-18-FDG PET/CT scans within two weeks before and after diagnosis. The control group included non-infected contralateral shoulder joints and patients who underwent F-18-FDG PET/CT for malignant melanoma staging without evidence of acute infections. Visual and quantitative analyses of F-18-FDG uptake, measured as SUVmax, were conducted. Osteoarthritis severity was categorized using the Kellgren and Lawrence system. To establish a cut-off for septic shoulder arthritis, a joint-liver-ratio was calculated using the SUVmax of the shoulder joint and liver. Intra- and interobserver reliability were assessed through repeated measurements. Of 150 shoulders 149 were included in the study: 13 into the experimental group with confirmed septic arthritis and 136 into the control group. One shoulder was excluded from the control group due to metastasis. Thirteen shoulders had confirmed septic arthritis. In the control group F-18-FDG uptake measured by SUVmax increased significantly with osteoarthritis severity (p=0.001). Septic shoulder arthritis exhibited markedly higher F-18-FDG uptake compared to controls (p<0.001). Visual intensity assessments corroborated these findings (p<0.001). For a cut-off value of 1 for the joint-liver-ratio, sensitivity, specificity, positive predictive value and negative predictive value for distinguishing between septic shoulder arthritis and osteoarthritis were 92.3%, 80.9%, 31.6% and 99.1%, respectively. Inter- and intraobserver reliability were moderate to high. The intraclass correlation coefficients (ICC) for SUV measurements in the total shoulder were 0.994 and 0.996, respectively, while Cohen's kappa coefficients for visual analysis were 0.570 and 0.891. F-18-FDG PET/CT effectively differentiates septic shoulder arthritis from varying stages of osteoarthritis. The SUVmax in liver can be used as a cut-off value with high sensitivity and specificity. A negative F-18-FDG PET/CT excludes septic shoulder arthritis.

Aim To update the subject-specific, competence-based catalog of learning objectives for medical studies in Germany published by the German Society of Nuclear Medicine (DGN) in 2018, prioritizing relevant learning objectives. Methods Based on the previous catalog, the writing group compiled nuclear medicine topics and formulated competence-based learning objectives, including medical developments, device innovations and new radiopharmaceutical approvals. These were presented for prioritization to the 180 habilitated DGN members as an expert group in a Delphi process. The first round of voting assessed firstly the topics in terms of necessity or dispensability, and secondly the detailed learning objectives of the topics were assessed for their relevance to academic teaching in nuclear medicine. The results of the first survey were used to draft a catalog of learning objectives with final approval by the expert group in a second survey. The time available for teaching nuclear medicine was also recorded. Results The writing group developed 240 competence-based learning objectives from 41 topics. After a first Delphi round, 73 detailed competence-based learning objectives from 15 topics were compiled. The mean teaching time was 8.4 h for lectures, 3.7 h for seminars and 3.6 h for practical courses. In a second Delphi round, the agreement of the expert group was at least 95% for the selected topics and at least 90% for the detailed learning objectives. Summary The catalog of subject-specific learning objectives, updated by expert consensus, provides basic knowledge, skills and competences related to the most relevant diagnostic and therapeutic procedures in nuclear medicine, taking into account both long-established topics and recently introduced innovations.