Repeat it without me: Crowdsourcing the T1 mapping common ground via the ISMRM reproducibility challenge

PURPOSE: T1 mapping is a widely used quantitative MRI technique, but its tissue-specific values remain inconsistent across protocols, sites, and vendors. The ISMRM Reproducible Research and Quantitative MR study groups jointly launched a challenge to assess the reproducibility of a well-established inversion-recovery T1 mapping technique, using acquisition details from a seminal T1 mapping paper on a standardized phantom and in human brains. METHODS: The challenge used the acquisition protocol from Barral et al. (2010). Researchers collected T1 mapping data on the ISMRM/NIST phantom and/or in human brains. Data submission, pipeline development, and analysis were conducted using open-source platforms. Intersubmission and intrasubmission comparisons were performed. RESULTS: Eighteen submissions (39 phantom and 56 human datasets) on scanners by three MRI vendors were collected at 3 T (except one, at 0.35 T). The mean coefficient of variation was 6.1% for intersubmission phantom measurements, and 2.9% for intrasubmission measurements. For humans, the intersubmission/intrasubmission coefficient of variation was 5.9/3.2% in the genu and 16/6.9% in the cortex. An interactive dashboard for data visualization was also developed: https://rrsg2020.dashboards.neurolibre.org. CONCLUSION: The T1 intersubmission variability was twice as high as the intrasubmission variability in both phantoms and human brains, indicating that the acquisition details in the original paper were insufficient to reproduce a quantitative MRI protocol. This study reports the inherent uncertainty in T1 measures across independent research groups, bringing us one step closer to a practical clinical baseline of T1 variations in vivo

Human papillomavirus types 16 and 18 and the prognosis of patients with stage I cervical cancer

OBJECTIVE: This study sought to evaluate the prevalence of human papillomavirus (HPV) types 16 and 18 in women with clinical stage IB cervical cancer treated by radical hysterectomy with pelvic lymphadenectomy as well as to establish a correlation between HPV type and cancer prognosis. METHODS: A single-center cohort study was conducted with 86 patients who had undergone radical hysterectomy for stage I cervical cancer. Prognostic factors and the presence of HPV 16 and 18 were analyzed using a polymerase chain reaction assay. A univariate analysis using Kaplan-Meier curves was conducted to estimate survival. RESULTS: The prevalence of HPV 16 in the study group was 65.3%, and the prevalence of HPV 18 was 33.3%. The prevalence of infection with both viruses was 26.9%. Overall survival at 5 years was 91% among women with HPV 18 and 96% among those without this virus type (p = 0.133). Among the women with HPV 16, the overall survival was 94%, whereas this rate was 96% among those without this virus type (p = 0.663). Disease-free survival was unaffected by the presence of HPV type 16 or 18. CONCLUSION: In the present study, despite the high prevalence of HPV types 16 and 18, the presence of these virus types did not affect the prognosis of patients with stage I cervical cancer who underwent radical hysterectomy