Sander Jentjens

Introduction: Idiopathic inflammatory myopathies are a heterogeneous group of disorders with overlapping clinical and imaging features. Advanced imaging such as 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is increasingly used. The “tiger man” sign is a rare nuclear imaging sign associated with sarcoid myopathy and has been previously described in only two case reports of non-sarcoid myopathy. Eosinophilic fasciitis and myositis lie within a spectrum of eosinophil-associated disorders, for which evidence-based treatment remains limited. In this context, histopathological insights may offer significant diagnostic and therapeutic value. Case description: A 68-year-old male presented with pain and oedema of the lower legs and forearms, accompanied by recurrent nocturnal fever. He had a prior diagnosis of eosinophilic fasciitis two years earlier. Proximal muscle weakness of the upper legs was noted. Laboratory tests revealed systemic inflammation and elevated creatine kinase (CK) levels, suggestive of an inflammatory myopathy, while screening for infections and autoimmune serology was negative. 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) imaging demonstrated a “tiger man” sign, characterized by extensive patchy 18F-FDG uptake in the skeletal muscles of all four extremities. Histopathological analysis confirmed a T-cell-mediated, necrotizing eosinophilic myositis, with no evidence of sarcoidosis or malignancy. Treatment with tacrolimus and plasma exchange resulted in significant clinical improvement and regression of 18F-FDG PET abnormalities. Conclusion: This is the third report of the “tiger man” sign in a patient with a non-sarcoid myopathy, thereby expanding the differential diagnosis for this imaging finding. Whole-body imaging can identify hypermetabolic yet clinically silent muscular regions, thereby guiding a more accessible and relevant site for biopsy. Histopathological findings can enhance diagnostic certainty and guide a more effective treatment.

Purpose This study aims to evaluate differences in PET/CT imaging of meningioma using both gallium-68- and fluorine-18-labelled somatostatin receptor (SSTR) tracers, to characterize incidentally detected meningiomas on SSTR PET/CT, and to analyse institutional experience with Peptide Receptor Radionuclide Therapy (PRRT) in meningioma. Methods This single centre retrospective study included all SSTR PET/CT scans of meningioma patients (2007-2024) performed with [⁶⁸Ga]Ga-DOTATOC, [⁶⁸Ga]Ga-DOTATATE or [¹⁸F]AlF-NOTA-octreotide. For lesions ≥ 1cm³, tumour uptake was quantified using three distinct delineation methods: an absolute SUV threshold of 2.3, a relative threshold of 1.73 × SUV_peak of a meningeal reference region, and a relative threshold of 11% of the lesion’s SUV_max. Tumour-to-background ratios were calculated. Meningioma patients treated with PRRT were identified from our institutional registry (2016-2024). Results Of 4,136 SSTR PET/CTs, 152 patients with 171 SSTR-expressing meningiomas were included. Incidental meningiomas were found in 3.7% of patients imaged for unrelated indications. Quantitative analysis of 86 lesions (≥ 1 cm³) showed robust uptake for [¹⁸F]AlF-NOTA-octreotide (n = 7), [⁶⁸Ga]Ga-DOTATATE (n = 73), and [⁶⁸Ga]Ga-DOTATOC (n = 6), without significant between-tracer differences across delineation strategies. All tracers demonstrated high tumour‐to‐meningeal uptake ratios with ratios ranging from 51 to 146 for [¹⁸F]AlF-NOTA-octreotide, 10-329 for [⁶⁸Ga]Ga-DOTATATE, and 12-76 for [⁶⁸Ga]Ga-DOTATOC, confirming excellent tumour-to-background contrast. Among 12 heavily pretreated patients receiving PRRT, disease control rate was 50%, median progression-free survival 8 months, and overall survival 20 months. Conclusion SSTR PET/CT enables high-contrast meningioma visualisation. [¹⁸F]AlF-NOTA-octreotide seems clinically interchangeable with gallium-68-labelled tracers, while offering logistical advantages. PRRT achieves meaningful disease stabilisation, supporting further validation in prospective randomised studies.

To investigate the diagnostic performance and interreader agreement of intraprostatic prostate cancer (PCa) detection, local extension and staging using [1

Background: Septic arthritis (SA) of the native adult hip is a rare orthopaedic emergency requiring prompt diagnosis and treatment. As clinical presentation and laboratory findings are frequently atypical, advanced imaging is often requested. This retrospective study aimed to investigate the prevalence and pattern of extra-articular infectious manifestations and their implications for pre-operative advanced imaging in patients with proven SA of the native hip joint. Methods: Out of 41 patients treated surgically for SA of the native hip during a 16-year period at our tertiary referral hospital, 25 received advanced imaging (computed tomography (CT), magnetic resonance imaging (MRI), or fluorodeoxyglucose positron emission tomography (FDG PET-CT)) prior to initial intervention. For each investigation, a specific set of variables was systematically interpreted, and the most suitable surgical approach was determined. The prognostic value was evaluated by comparing specific outcome measures and the extent of extra-articular involvement. Results: It was found that 32 % of patients had an abscess in one anatomical region, 32 % of patients had abscesses in multiple anatomical regions, and only 36 % of patients had no substantial abscess. Gluteal abscesses were especially common in patients with SA due to contiguous spread. Abscesses in the iliopsoas region were more common in patients with SA due to hematogenous seeding. A combination of several different surgical approaches was deemed necessary to adequately deal with the various presentations. No significant prognostic factors could be identified. Conclusion: We recommend performing advanced imaging in patients with suspected or proven septic arthritis of the native hip joint, as extra-articular abscesses are present in 64 % and might require varying anatomical approaches.

Background and purpose: Enterovirus infections pose a serious threat for patients with humoral deficiencies and may be lethal, whilst the efficacy of proposed treatment options such as corticosteroids, intravenous immunoglobulins and fluoxetine remains debated.Methods: Viral clearance was investigated in a patient with rituximab‐induced B‐cell depletion and chronic echovirus 13 (E13) meningoencephalitis/myofasciitis in response to intravenous immunoglobulins and fluoxetine using sequential semi‐quantitative E13 viral load measurements by real‐time reverse transcription polymerase chain reaction. Fluoxetine concentrations in plasma and cerebrospinal fluid were determined by liquid chromatography mass spectrometry.Results: Intravenous immunoglobulins appeared ineffective in this case of E13 infection, whereas virus clearance in cerebrospinal fluid was obtained after 167 days of oral fluoxetine. Since treatment with corticosteroids resulted in a flare of symptoms, rechallenge with viral load measurements was not attempted.Conclusion: In this report of a patient with rituximab‐associated chronic echovirus 13 meningoencephalitis, viral clearance in response to single treatment options is assessed for the first time. Our observations further support the in vivo efficacy of fluoxetine against enteroviral infections. More research is needed to establish its efficacy in different enterovirus strains.

18F-FDG PET/CT is a valuable diagnostic tool in infective endocarditis (IE). However, the prognostic value is unclear. This study aims to evaluate the prognostic performance of 18F-FDG PET/CT in na...

Although concomitant coronary artery disease (CAD) is frequent in patients with severe aortic stenosis (AS), hemodynamic assessment of CAD severity in patients undergoing valve replacement for severe AS is challenging. Myocardial hypertrophic remodeling interferes with coronary blood flow and may influence the values of fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs). The aim of the current study is to investigate the effect of the AS and its treatment on current indices used for evaluation of CAD. We will compare intracoronary hemodynamics before, immediately after, and 6 mo after aortic valve replacement (AVR) when it is expected that microvascular function has improved. Furthermore, we will compare FFR and resting full-cycle ratio (RFR) with myocardial perfusion single-photon emission-computed tomography (SPECT) as indicators of myocardial ischemia in patients with AS and CAD. One-hundred consecutive patients with AS and intermediate CAD will be prospectively included. Patients will undergo pre-AVR SPECT and intracoronary hemodynamic assessment at baseline, immediately after valve replacement [if transcatheter AVR (TAVR) is chosen], and 6 mo after AVR. The primary end point is the change in FFR 6 mo after AVR. Secondary end points include the acute change of FFR after TAVR, the diagnostic accuracy of FFR versus RFR compared with SPECT for the assessment of ischemia, changes in microvascular function as assessed by the index of microcirculatory resistance (IMR), and the effect of these changes on FFR. The present study will evaluate intracoronary hemodynamic parameters before, immediately after, and 6 mo after AVR in patients with AS and intermediate coronary stenosis. The understanding of the impact of AVR on the assessment of FFR, NHPR, and microvascular function may help guide the need for revascularization in patients with AS and CAD planned for AVR.

Objectives PSMA-PET has become the PET technique of choice to localise the site of biochemically recurrent prostate cancer (PCa). With hybrid PET/MRI, the advantages of MRI are added to molecular characteristic of PET. The aim of this study was to investigate the incremental value of PET/MR versus PET/CT in patients with biochemically recurrent PCa by head-to-head comparison. Methods Thirty-four patients with biochemically recurrent PCa were prospectively included. They underwent [⁶⁸Ga]Ga-PSMA-11 PET/CT, followed by simultaneous PET/MR. All PET (PET_CT, PET_MR), CT and MR images were evaluated for number of lesions and location. The number of lesions at specific sites was compared using Wilcoxon-sign-rank test. For PET, the maximum and mean standardised uptake values (SUVs) were calculated for each lesion compared using a two-sided paired t test. Results PET_CT and PET_MR scans were positive in 19 and 20 patients, detecting 73 and 79 lesions respectively. All lesions detected on PET_CT were also detected on PET_MR. CT and MRI only were positive in 14 and 17 patients, detecting 38 and 50 lesions, respectively, which was significantly lower than PET_CT and PET_MR respectively. Combined interpretation showed more lesions on PET/MR than on PET/CT (88 vs 81). No significant difference in detection of presence of local recurrence nor distant metastases was found. SUV_mean and SUV_max values were significantly higher on PET_MR than on PET_CT in local recurrence and lymph node metastases. Conclusions [⁶⁸Ga]Ga-PSMA-11 PET/MR was able to detect biochemically recurrent PCa at least as accurately as PET/CT for local recurrence, lymph node metastasis and distant metastasis. Key Points • PSMA PET/MRI detects the location of biochemical recurrence at least as accurately as PET/CT. • Substitution of PET/CT by PET/MRI adds sensitivity in PSMA lesion detection also in the setting of distant recurrence due to both the MR and TOF PET components.