Objectives Molecular assays on nasopharyngeal swabs remain the cornerstone of COVID-19 diagnostic. The high technicalities of nasopharyngeal sampling and molecular assays, as well as scarce resources of reagents, limit our testing capabilities. Several strategies failed, to date, to fully alleviate this testing process (e.g. saliva sampling or antigen testing on nasopharyngeal samples). We assessed the clinical performances of SARS-CoV-2 nucleocapsid antigen (N-antigen) ELISA detection in serum or plasma using the COVID-19 Quantigene® (AAZ, France) assay. Methods Performances were determined on 63 sera from 63 non-COVID patients and 227 serum samples (165 patients) from the French COVID and CoV-CONTACT cohorts with RT-PCR confirmed SARS-CoV-2 infection, including 142 serum (114 patients) obtained within 14 days after symptoms’ onset. Results Specificity was 98.4% (95% confidence interval [CI], 95.3 to 100). Sensitivity was 79.3% overall (180/227, 95% CI, 74.0 to 84.6) and 93.0% (132/142, 95% CI, 88.7 to 97.2) within 14 days after symptoms onset. 91 included patients had a sera and nasopharyngeal swabs collected in the same 24 hours. Among those with high nasopharyngeal viral loads, i.e. Ct value below 30 and 33, only 1/50 and 4/67 tested negative for N-antigenemia, respectively. Among those with a negative nasopharyngeal RT-PCR, 8/12 presented positive N-antigenemia; the lower respiratory tract was explored for 6 of these 8 patients, showing positive RT-PCR in 5 cases. Conclusion This is the first evaluation of a commercially available serum N-antigen detection assay. It presents a robust specificity and sensitivity within the first 14 days after symptoms onset. This approach provides a valuable new option for COVID-19 diagnosis, only requiring a blood draw and easily scalable in all clinical laboratories.

• MRI is an important modality for outcome prediction in HIFU treatment • Patient selection is a significant factor for achieving high NPV ratio • NPV ratio is very strongly correlated with T1 perfusion-based classification • T1 perfusion-based classification is a strong predictor of treatment outcome.

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View related articles View Crossmark data Citing articles: 1 View citing articles Magnetic resonance imaging features influencing high-intensity focused ultrasound ablation of adenomyosis with a nonperfused volume ratio of !90% as a measure of clinical treatment success: retrospective multivariate analysis

Our novel classification method introduced in this study might be clinically beneficial in classifying adenomyosis for predicting the immediate outcome of MR-guided high intensity focused ultrasound treatment.

U terine fibroids, composed of smooth muscle cells and fibrous connective tissue derived from the myometrium, are common benign gynecological tumors that have a significant negative effect on the quality of life of a patient. Symptoms of uterine fibroids vary depending on their size and location, but the main symptoms are pelvic pain, menorrhagia or dysmenorrhea, increased frequency of urination, and reproductive dysfunction, including impaired fertility, pregnancy complications and loss (1, 2).The choice of treatment and its rate of success are dependent on the morphology and tissue characteristics of the uterine fibroids. Hysterectomy remains the definitive treatment for uterine fibroids, but this treatment option is unsuitable for women who wish to preserve their fertility. In the last decade, patient demands have spurred the development of a noninvasive therapeutic modality for symptomatic uterine fibroids called magnetic resonance imaging-guided high-intensity focused ultrasound (MRI-guided HIFU) (3-11).The principle of HIFU treatment of uterine fibroids is that focused ultrasonic energy causes coagulative necrosis of the target. Since its first clinical use for treating symptomatic uterine fibroids, the use of HIFU has increased worldwide because of its excellent therapeutic efficacy in relieving fibroid-related symptoms, its ability to preserve the uterus, and its high level of safety (3-7). However, as shown in previous studies (8-11), MRI-guided HIFU ablation therapy cannot be used in all patients with symptomatic fibroids because of the tissue characteristics of the uterine fibroids such as the T1 and T2 MRI signal intensity (SI), and fibroid type defined by general uterine position, fibroid size, and fibroid number. In addition, technical limitations, including the presence of scar tissue, excessive abdominal subcutaneous fat, the distance between the skin and the fibroids, the distance between the sacral bone surface and the fibroids, and the bowel in the path of sonication, play a role in whether MRI-guided HIFU therapy is appropriate.In this article, we present a literature review of the influential clinical factors that might reduce the risk of an unsuccessful MRI-guided HIFU treatment outcome of uterine fibroids. Tissue characteristics of uterine fibroids T2-weighted imagingT2 SI is the primary MRI classification parameter for determining patient suitability for MRI-guided HIFU. A patient is classified as type I when the SI of the uterine fibroid is lower than that of skeletal muscle, type II when the SI is lower than that of the myometrium but higher than that of skeletal muscle, or type III when the SI is higher than that of the myometrium (Fig. 1) (4). As shown by previous studies (4-13), uterine fibroids with different SIs on ABSTRACTMagnetic resonance imaging-guided high-intensity focused ultrasound (MRI-guided HIFU) is an effective noninvasive treatment option for symptomatic uterine fibroids. However, tissue characteristics of uterine fibroids and technical limitations can limit the patie...

BACKGROUND:Magnetic Resonance Imaging (MRI) nowadays plays an important role in the evaluation of posterior fossa brain tumours in children for appropriate diagnosis, treatment planning, and follow-up.AIM:To assess the MRI features of common posterior fossa brain tumours including medulloblastomas, ependymomas, and pilocytic astrocytomas along with the postoperative parameters to contribute the local knowledge to the neuroradiology and neurosurgery fields.METHODS:The study was performed at Children’s Hospital 02 from January 2016 to June 2019. In this study, all pediatric patients adopted MRI to evaluate the posterior fossa brain tumours’ characteristics and then underwent surgery to eradicate the posterior fossa tumours. We retrospectively compared the baseline parameters, MRI parameters, and postoperative parameters among medulloblastomas, ependymomas, and pilocytic astrocytomas.RESULTS:There were 62 patients (27 medulloblastomas, 20 ependymomas, and 15 pilocytic astrocytomas) in this research. The main structure of medulloblastomas and ependymomas was predominantly solid, whereas the main structure of pilocytic astrocytomas was superiorly cystic (p < 0.05). Ependymoma tended to extend tumour through foramina of Luschka and Magendie (p < 0.05). Medulloblastomas chiefly showed iso intensity on T2W and FLAIR images meanwhile ependymomas and pilocytic astrocytomas predominantly appeared hyperintensity on T2W and FLAIR images. Medulloblastomas and ependymomas were mostly high intensity on DWI, and low intensity on ADC whereas pilocytic astrocytomas were usually low intensity on DWI and high intensity on ADC. After injecting CE, pilocytic astrocytomas showed a mixed intensity whereas the signal intensity of medulloblastoma and ependymoma on T1CE was generally strong. There were positive correlations between FH diameter and estimated blood loss (r = 0.289, p < 0.05); and surgical time (r = 0.312, p < 0.05).CONCLUSION:MRI plays a crucial role in demonstrating the features of posterior fossa brain tumours for appropriate diagnosis of medulloblastomas, ependymomas, and pilocytic astrocytomas. Medulloblastomas are problematic tumours and the clinicians should also take into consideration in cases of larger feet-to-head diameter of tumours to ensure the efficacy and safety surgery for patients.