Scatter correction in scintigraphy: the state of the art

In scintigraphy, the detection of scattered photons degrades both visual image analysis and quantitative accuracy. Many methods have been proposed and are still under investigation to cope with scattered photons. The main features of the problem of scattering in radionuclide imaging are presented first, to provide a sound foundation for a critical review of the existing scatter correction techniques. These are described using a classification relating to their aims and principles. Their theoretical potentials are analysed, as well as the difficulties of their practical implementation. Finally, the problems of their evaluation and comparison are discussed. Correspondence to: I. Buvat     

Abortive potency of Chlamydophila abortus in pregnant mice is not directly correlated with placental and fetal colonization levels

Abortion, placental and fetal colonization, and levels of gamma interferon were analyzed for four Chlamydophila abortus strains presenting antigenic variations in a mouse model. Expression of virulence of these strains varied and indicated that abortion was not directly related to the number of bacteria in the placenta, and thus, other factors may have an important role in activating the abortion process.     

Takayasu’s arteritis occurring under TNF blockers in a patient with spondyloarthritis: is it an association or a paradoxical effect?

Coexistence of spondyloarthritis (SpA) and Takayasu’s arteritis is not a common finding, but such cases have been discussed, particularly in the context of choice of therapy. Inhibition of inflammation by tumor necrosis factor inhibitors (TNFi) is a key aspect of the treatment of SpA and also positive effects of such treatment in concomitant large vessel vasculitis have been reported. However, TNFi is also associated with the possibility of initiating vasculitis.The present article based on a case study and the available literature is an attempt to discuss coexistence of these two diseases and the impact of treatment with biological drugs from the anti-TNF group in the course of SpA with Takayasu’s arteritis.     

Combined effect of Controlling Nutritional Status and Acute Kidney Injury on severe COVID-19 short-term outcomes

Introduction/ObjectivesAcute kidney injury (AKI) and malnutrition are two complications commonly reported in severe forms of COVID-19, their combined effect on short-term mortality is, however, not yet investigated. The objective of this study is to determine both their individual and combined effects on short-term prognosis.Materials and methodsThis is a prospective, uni-centric study, including 247 severe COVID-19 patients, admitted between April 25th and June 20th, 2020, at the University Hospital of Blida. AKI was defined according to the KDIGO-2012 guidelines. Nutritional status was assessed using the Controlling Nutritional Status (CONUT) score. The association with in-hospital mortality was assessed using the Kaplan-Meier method and proportional Cox regression.ResultsAmong the 247 severely affected COVID-19 patients included in this study, 34.4% developed AKI, 30.4 and 1.2%, respectively, had moderate and severe CONUT scores, 17.7% worsened and progressed to a critical state and 26.7% did not survive. Both AKI and CONUT score were significantly associated with mortality in a dose-response manner (pLog-Rank < 0.0001). Their relative risks are respectively (HR = 3.25 CI 95% [1.99–5.3] and HR = 2.42 CI 95% [1.5–3.9], p < 0.0001). In multivariate analysis, the highest risk was observed for the AKI-CONUT-high combination (HR = 3.0, 95% CI [1.5–6.1], p = 0.002).ConclusionA possible synergistic interaction between AKI and CONUT score for COVID-19 short-term mortality has been highlighted. Monitoring of renal function associated with assessment of nutritional status should be performed routinely and systematically from the early stages of admission.     

Proton magnetic resonance spectroscopy of the medial prefrontal cortex in patients with deficit schizophrenia: preliminary report

OBJECTIVE: Proton magnetic resonance spectroscopy (1H-MRS) was used to study medial prefrontal metabolic impairments in schizophrenic patients with the deficit syndrome. METHOD: The subjects were 22 schizophrenic patients categorized as deficit (N=5) or nondeficit (N=17) and 21 healthy subjects. (1)H-MRS was performed for the right and the left medial prefrontal cortex. RESULTS: The patients with the deficit syndrome had significantly lower ratios of N-acetylaspartate to creatine plus phosphocreatine than did the healthy subjects or nondeficit patients. CONCLUSIONS: As N-acetylaspartate levels could reflect neuronal density and/or viability, this finding suggests a neuronal loss in the medial prefrontal cortex of deficit patients.     

Testicular Synovial Sarcoma:A Case Report

This paper reports a case of testicular synovial sarcoma with molecular genetic analysis.A 24-year-old male presented with painless scrotal mass.Ultrasonography showed a heterogeneous mass of 66 mm×34 mm in size involving the inguinal region.Histological examination of a surgical biopsy showed a gradeⅢmonophasic growth pattern of spindle cell proliferation.Immunohistochemical analyses indicated positive staining for pancytokeratine and epithelial membrane antigen.Cytogenetic analysis showed the presence of CYT-SSX1 mutation,and CT scan showed non-specific pleural micro-nodules with a size of 7.5 mm.The patient had an extended left orchidectomy but was lost to follow-up for 1 year.A local recurrent scrotal mass of 32 mm×25 mm,multiple inguinal lymph nodes,and increased pleural nodules,which were confirmed by histological examination,were treated with three cycles of adriamycine and ifosfamide chemotherapy,surgical resection,and radiotherapy with complete response.After 3 months,the patient developed local recurrence and pulmonary metastases that did not respond to second-line chemotherapy based on gemcitabine and paclitaxel.The patient had dyspnea at the time of this writing and chest pain,and is under third-line chemotherapy based on Deticene after 30 months of following up.This patient died on November 16,2012 after a resperatory failure and malignant plural effusion. Synovial sarcoma should be considered in the differential diagnosis of soft tissue tumor and it should be aggressively treated to improve prognosis.Although our patient has shown numerous factors of bad prognosis,he has had a relatively long survival time.