Combined 68Ga-DOTATOC and 18F-FDG PET Predicts a Double Component With Different Grade of a Pancreatic Neuroendocrine Tumor in a Patient With Multiple Endocrine Neoplasia Type 1.

Managing decisions of pancreatic neuroendocrine tumors (pNETs) can be challenging because of different clinical presentations and prognosis. A 31-year-old woman with multiple endocrine neoplasia type 1, including a suspicious pNET, was assessed with Ga-DOTATOC and F-FDG PET. A high Ga-DOTATOC uptake was visualized in the entire pNET, whereas a high F-FDG PET uptake was present only in the upper part of the tumor. After surgery, pathology confirmed the pNET with a double component: an upper grade 2 with a Ki67 of 11% with the high F-FDG PET uptake, and a lower grade 1 with a Ki67 of 2%. Combined Ga-DOTATOC/F-FDG PET predicts the grade in heterogeneous pNETs.

CD8+ T cell-mediated endotheliopathy is a targetable mechanism of neuro-inflammation in Susac syndrome.

Neuroinflammation is often associated with blood-brain-barrier dysfunction, which contributes to neurological tissue damage. Here, we reveal the pathophysiology of Susac syndrome (SuS), an enigmatic neuroinflammatory disease with central nervous system (CNS) endotheliopathy. By investigating immune cells from the blood, cerebrospinal fluid, and CNS of SuS patients, we demonstrate oligoclonal expansion of terminally differentiated activated cytotoxic CD8+ T cells (CTLs). Neuropathological data derived from both SuS patients and a newly-developed transgenic mouse model recapitulating the disease indicate that CTLs adhere to CNS microvessels in distinct areas and polarize granzyme B, which most likely results in the observed endothelial cell injury and microhemorrhages. Blocking T-cell adhesion by anti-α4 integrin-intervention ameliorates the disease in the preclinical model. Similarly, disease severity decreases in four SuS patients treated with natalizumab along with other therapy. Our study identifies CD8+ T-cell-mediated endotheliopathy as a key disease mechanism in SuS and highlights therapeutic opportunities.

Usefulness of 18 F-Labeled Fluorodeoxyglucose-Positron Emission Tomography for the Diagnosis of Lymphoma in Primary Sjögren's Syndrome.

OBJECTIVE: The usefulness of positron emission tomography-computed tomography (PET-CT) with 18 F-labeled fluorodeoxyglucose (18 F-FDG) for the diagnosis of lymphoma in patients with primary Sjögren's syndrome (SS) is unclear, since the abnormalities it reveals may be due to systemic manifestations of SS. This study was undertaken to compare 18 F-FDG-PET-CT in patients with primary SS with lymphoma and those without lymphoma in order to identify patterns associated with lymphoma. METHODS: A retrospective study was conducted in 2 centers and included patients who met the American College of Rheumatology/European League Against Rheumatism 2016 criteria for primary SS and had undergone PET-CT. Two independent readers who were blinded with regard to lymphoma diagnosis analyzed PET-CT scans. Abnormalities were compared between patients with and those without lymphoma. RESULTS: Of the 45 patients included, 15 had lymphoma. Compared to patients without lymphoma, the mean size (P = 0.048) and maximum standardized uptake value (SUVmax) (P = 0.001) of the parotid glands were higher in patients with lymphoma. FDG uptake in the lymph nodes was observed in 53.3% of the patients with lymphoma and 43.3% of the patients without lymphoma, with no difference in the number of sites, uptake pattern, or mean SUVmax. Focal pulmonary uptake (nodules or condensations) was observed in 5 of the patients with lymphoma (33.3%) but only 1 patient without lymphoma (3.3%) (P = 0.01). Having an SUVmax in the parotid gland of ≥4.7 and/or the presence of focal pulmonary lesions was highly suggestive of lymphoma (sensitivity 80%, specificity 83.3%). CONCLUSION: Some systemic manifestations of primary SS (lymphadenopathy, pulmonary involvement, and salivary gland involvement) can be visualized by PET-CT. Involvement of the lymph nodes and parotid glands is commonly observed with a similar frequency in SS patients with and those without lymphoma. An SUVmax in the parotid glands of ≥4.7 and/or the presence of focal lung lesions are associated with the diagnosis of lymphoma.

Rapid Contour-based Segmentation for 18F-FDG PET Imaging of Lung Tumors by Using ITK-SNAP: Comparison to Expert-based Segmentation.

Purpose To assess the performance of the ITK-SNAP software for fluorodeoxyglucose (FDG) positron emission tomography (PET) segmentation of complex-shaped lung tumors compared with an optimized, expert-based manual reference standard. Materials and Methods Seventy-six FDG PET images of thoracic lesions were retrospectively segmented by using ITK-SNAP software. Each tumor was manually segmented by six raters to generate an optimized reference standard by using the simultaneous truth and performance level estimate algorithm. Four raters segmented 76 FDG PET images of lung tumors twice by using ITK-SNAP active contour algorithm. Accuracy of ITK-SNAP procedure was assessed by using Dice coefficient and Hausdorff metric. Interrater and intrarater reliability were estimated by using intraclass correlation coefficients of output volumes. Finally, the ITK-SNAP procedure was compared with currently recommended PET tumor delineation methods on the basis of thresholding at 41% volume of interest (VOI; VOI41) and 50% VOI (VOI50) of the tumor's maximal metabolism intensity. Results Accuracy estimates for the ITK-SNAP procedure indicated a Dice coefficient of 0.83 (95% confidence interval: 0.77, 0.89) and a Hausdorff distance of 12.6 mm (95% confidence interval: 9.82, 15.32). Interrater reliability was an intraclass correlation coefficient of 0.94 (95% confidence interval: 0.91, 0.96). The intrarater reliabilities were intraclass correlation coefficients above 0.97. Finally, VOI41 and VOI50 accuracy metrics were as follows: Dice coefficient, 0.48 (95% confidence interval: 0.44, 0.51) and 0.34 (95% confidence interval: 0.30, 0.38), respectively, and Hausdorff distance, 25.6 mm (95% confidence interval: 21.7, 31.4) and 31.3 mm (95% confidence interval: 26.8, 38.4), respectively. Conclusion ITK-SNAP is accurate and reliable for active-contour-based segmentation of heterogeneous thoracic PET tumors. ITK-SNAP surpassed the recommended PET methods compared with ground truth manual segmentation.

Endothelial cells and lymphatics at the interface between the immune and central nervous systems: implications for multiple sclerosis.

PURPOSE OF REVIEW: The central nervous system (CNS) has a unique relationship with the immune system. This review highlights the distinct roles of lymphatic vessels and endothelial cells in the interface between CNS and immune cells and invites to revisit the concept of CNS immune privilege. RECENT FINDINGS: T cells can follow several routes to penetrate the CNS parenchyma but may also benefit, together with antigen-loaded presenting cells, from the newly described lymphatic network to exit the CNS. CNS endothelial cells (EC) critically positioned at the interface between circulating immune cells and the CNS regulate the multistep cascade for immune cell trafficking into the CNS. They can also be considered as semiprofessional antigen-presenting cells through their ability to present antigens to T cells and to regulate their activation through co-stimulatory and inhibitory molecules. SUMMARY: The lymphatic network linking the CNS to draining lymph nodes may contribute to the inflammatory reaction occurring in multiple sclerosis (MS). The abundance and strategic positioning of endothelial cells at the blood-brain barrier level most likely endow them with an important role in controlling local adaptive immune responses, rendering them potential therapeutic targets in neuro-inflammatory such as MS.

PET/CT and MRI Imaging of a Eumycetoma of the Right Thigh.

Eumycetoma is a chronic tropical fungal disease that infiltrates subcutaneous tissues, mainly in the feet and legs. Standard antifungal drugs are ineffective, and mutilating surgery is common. Morphological imaging is useful for assessing the local extent of the disease before surgery. FDG PET/CT may be of potential interest for the general extent, but PET descriptions remain scarce and mostly relate to the feet. Here, the authors present FDG PET/CT and MRI study of a very rare case of an extensive, biopsy-proven eumycetoma of the right thigh that was performed to guide potential surgery.

Validation of early image acquisitions following Tc-99 m sestamibi injection using a semiconductors camera of cadmium-zinc-telluride.

BACKGROUND: Cadmium-zinc-telluride (CZT) cameras allow to decrease significantly the acquisition time of myocardial perfusion imaging (MPI), but the duration of the examination is still long. Therefore, this study was performed to test the feasibility of early imaging following injection of Tc-99 m sestamibi using a CZT camera. METHODS: Seventy patients underwent both an early and a delayed image acquisition after exercise stress test (n = 30), dipyridamole stress test (n = 20), and at rest (n = 20). After injection of Tc-99 m sestamibi, the early image acquisition started on average within 5 minutes for the exercise and rest groups, and 3 minutes 30 seconds for the dipyridamole group. Two independent observers evaluated image quality and extracardiac uptake on four-point scales. The difference between early and later images for each patient was scored on a five-point scale. RESULTS: The image quality and extracardiac uptake of early and delayed image acquisitions were not different for the three groups (P > .05). There was no significant difference between early and delayed image acquisitions in the exercise, dipyridamole, and rest groups, respectively, in 63%, 40%, and 80% of cases. In the exercise group and rest group, a defect was only present in early MPI, respectively, in 13% and 20% of cases. A defect was only present in delayed images in 10% of cases in the exercise group and in 45% of cases in the dipyridamole group. CONCLUSIONS: There was no difference between early and later image acquisitions in terms of quality. This protocol reduces the length of the procedure for the patient. Beginning with early image acquisitions may help to overcome the artifacts that are observed at the delayed time.

[Preventing falls in people with cognitive impairment]. / Prévenir les chutes en cas de troubles cognitifs.

The residence Eleusis in Poissy (78) is a nursing home for dependent elderly people, it specialises in the care of people with severe cognitive impairment. It offers weekly workshops in fall prevention. This is geared towards motor, cognitive and behavioural components in order to take into account the person as a whole.