Review and consensus recommendations on clinical APT-weighted imaging approaches at 3T: Application to brain tumors

Amide proton transfer-weighted (APTw) MR imaging shows promise as a biomarker of brain tumor status. Currently used APTw MRI pulse sequences and protocols vary substantially among different institutes, and there are no agreed-on standards in the imaging community. Therefore, the results acquired from different research centers are difficult to compare, which hampers uniform clinical application and interpretation. This paper reviews current clinical APTw imaging approaches and provides a rationale for optimized APTw brain tumor imaging at 3T, including specific recommendations for pulse sequences, acquisition protocols, and data processing methods. We expect that these consensus recommendations will become the first broadly accepted guidelines for APTw imaging of brain tumors on 3 T MRI systems from different vendors. This will allow more medical centers to use the same or comparable APTw MRI techniques for the detection, characterization, and monitoring of brain tumors, enabling multi-center trials in larger patient cohorts and, ultimately, routine clinical use

A Service of zbw Leibniz-Informationszentrum Wirtschaft Leibniz Information Centre for Economics Mass Media, Instrumental Information, and Electoral Accountability Mass Media, Instrumental Information, and Electoral Accountability

Standard-Nutzungsbedingungen: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in Abstract Journalism is widely believed to be crucial for holding elected officials accountable. At the same time economic theory has a hard time providing an instrumental explanation for the existence of "accountability journalism". According to the common Downsian reasoning, rational voters should not be willing to pay for information out of purely instrumental motives because the individual probabilities of casting the decisive vote are typically very low. We show that this rationale does not apply when a group of voters shares a common goal such as accountability and information is delivered via mass media. In contrast to the pessimistic Downsian view, rational voters can have a considerable willingness to pay for the provision of instrumental information in these scenarios. Our model thus reconciles the rational voter approach with the common perception of journalism as a watchdog that holds elected officials accountable. JEL-Codes: D72, D83, H4

The Traveling Heads 2.0: Multicenter Reproducibility of Quantitative Imaging Methods at 7 Tesla

ObjectThis study evaluates inter-site and intra-site reproducibility at ten different 7 T sites for quantitative brain imaging.Material and MethodsTwo subjects – termed the “traveling heads” – were imaged at ten different 7 T sites with a harmonized quantitative brain MR imaging protocol. In conjunction with the system calibration, MP2RAGE, QSM, CEST and multi-parametric mapping/relaxometry were examined.ResultsQuantitative measurements with MP2RAGE showed very high reproducibility across sites and subjects, and errors were in concordance with previous results and other field strengths. QSM had high inter-site reproducibility for relevant subcortical volumes. CEST imaging revealed systematic differences between the sites, but reproducibility was comparable to results in the literature. Relaxometry had also very high agreement between sites, but due to the high sensitivity, differences caused by different applications of the B1 calibration of the two RF coil types used were observed.ConclusionOur results show that quantitative brain imaging can be performed with high reproducibility at 7 T and with similar reliability as found at 3 T for multicenter studies of the supratentorial brain