Computer-aided diagnosis of prostate cancer in the peripheral zone using multiparametric MRI

International audienc

Prostate Focal Peripheral Zone Lesions: Characterization at Multiparametric MR Imaging--Influence of a Computer-aided Diagnosis System

International audiencePurpose To assess the impact of a computer-aided diagnosis (CAD) system in the characterization of focal prostate lesions at multiparametric magnetic resonance (MR) imaging. Materials and Methods Formal institutional review board approval was not required. Thirty consecutive 1.5-T multiparametric MR imaging studies (with T2-weighted, diffusion-weighted, and dynamic contrast material-enhanced imaging) obtained before radical prostatectomy in patients between September 2008 and February 2010 were reviewed. Twelve readers assessed the likelihood of malignancy of 88 predefined peripheral zone lesions by using a five-level (level, 0-4) subjective score (SS) in reading session 1. This was repeated 5 weeks later in reading session 2. The CAD results were then disclosed, and in reading session 3, the readers could amend the scores assigned during reading session 2. Diagnostic accuracy was assessed by using a receiver operating characteristic (ROC) regression model and was quantified with the area under the ROC curve (AUC). Results Mean AUCs were significantly lower for less experienced (<1 year) readers (P < .02 for all sessions). Seven readers improved their performance between reading sessions 1 and 2, and 12 readers improved their performance between sessions 2 and 3. The mean AUCs for reading session 1 (83.0%; 95% confidence interval [CI]: 77.9%, 88.0%) and reading session 2 (84.1%; 95% CI: 78.1%, 88.7%) were not significantly different (P = .76). Although the mean AUC for reading session 3 (87.2%; 95% CI: 81.0%, 92.0%) was higher than that for session 2, the difference was not significant (P = .08). For an SS positivity threshold of 3, the specificity of reading session 2 (79.0%; 95% CI: 71.1%, 86.4%) was not significantly different from that of session 1 (78.7%; 95% CI: 70.5%, 86.8%) but was significantly lower than that of session 3 (86.2%; 95% CI: 77.1%, 93.1%; P < .03). The sensitivity of reading session 2 (68.4%; 95% CI: 57.5%, 77.7%) was significantly higher than that of session 1 (64.0%; 95% CI: 52.9%, 73.9%; P = .003) but was not significantly different from that of session 3 (71.4%; 95% CI: 58.3%, 82.7%). Conclusion A CAD system may improve the characterization of prostate lesions at multiparametric MR imaging by increasing reading specificity

Evaluation clinique d'un système d'aide au diagnostic pour la caractérisation des zones suspectes en IRM multi-paramétrique de prostate

National audienc

Evaluation of a 3D MR/MR elastic registration method for prostate cancer imaging

International audienceEarly detection and localization of prostate cancer is crucial for appropriate patient management. Recent studies suggest that computer-assisted diagnosis systems combining different imaging modalities (MR/MR, MR/US) can improve prostate cancer detection1 and open the wayto targeted biopsies and focal therapy2. Such fusion processes are limited by prostate motion and deformation, particularly at the prostate-rectum interface. A non-rigid multimodal image registration process based on shape statistics has been developed to coregister T2-weighted MR and 3D transrectal ultrasound acquisitions3. Based on the good precision achieved4, this method was adapted to coregister T2-weighted, diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) images and evaluated on 28 prostate cancer patients

Differentiation of transitional zone prostate cancer from benign hyperplasia nodules: evaluation of discriminant criteria at multiparametric MRI

International audienc

Variability induced by the MR imager in dynamic contrast-enhanced imaging of the prostate

International audiencePURPOSE:To evaluate the variability induced by the imager in discriminating high-grade (Gleason≥7) prostate cancers (HGC) using dynamic contrast-enhanced MRI.MATERIAL AND METHODS:We retrospectively selected 3T MRIs with temporal resolution<10 seconds and comprising T1 mapping from a prospective radiologic-pathologic database of patients treated by prostatectomy. Ktrans, Kep, Ve and Vp were calculated for each lesion seen on MRI using the Weinmann arterial input function (AIF) and three patient-specific AIFs measured in the right and left iliac arteries in pixels in the center of the lumen (psAIF-ST) or manually selected by two independent readers (psAIF-R1 and psAIF-R2).RESULTS:A total of 43 patients (mean age, 63.6±4.9 [SD]; range: 48-72 years) with 100 lesions on MRI (55 HGC) were selected. MRIs were performed on imager A (22 patients, 49 lesions) or B (21 patients, 51 lesions) from two different manufacturers. Using the Weinmann AIF, Kep (P=0.005), Ve (P=0.04) and Vp (P=0.01) significantly discriminated HCG. After adjusting on tissue classes, the imager significantly influenced the values of Kep (P=0.049) and Ve (P=0.007). Using patient-specific AIFs, Vp with psAIF-ST (P=0.008) and psAIF-R2 (P=0.04), and Kep with psAIF-R1 (P=0.03) significantly discriminated HGC. After adjusting on tissue classes, types of patient-specific AIF and side of measurement, the imager significantly influenced the values of Ktrans (P=0.0002), Ve (P=0.0072) and Vp (P=0.0003). For all AIFs, the diagnostic value of pharmacokinetic parameters remained unchanged after adjustment on the imager, with stable odds ratios.CONCLUSION:The imager induced variability in the absolute values of pharmacokinetic parameters but did not change their diagnostic performance

Patient Science als bürgerwissenschaftliches Format: Erkenntnisse aus dem Pilotprojekt und Empfehlungen für zukünftige Projekte

Das Citizen Science-Projekt „Patient Science zur Erforschung Seltener Erkrankungen – eine bürgerwissenschaftliche Studie am Beispiel der Mukoviszidose“ wurde von 2017 bis 2020 vom Bundesministerium für Bildung und Forschung (BMBF) gefördert. Es wollte dezidiert ein bürgerwissenschaftliches Format für die Gesundheits- und medizinische Forschung erproben, das ein höchstes Maß an Partizipation für Bürger:innen bzw. Patient:innen ermöglicht, und zwar in allen Phasen des Forschungsprozesses. Das Forschungsteam bestand aus zwölf Patient:innen mit der chronischen Erkrankung Mukoviszidose und Angehörigen einerseits (den Patient Scientists bzw. Patientenforscher:innen) sowie aus acht professionellen Forscher:innen aus Sozialwissenschaften, Psychologie und Medizin bzw. ärztlichen und psychologischen Behandler:innen andererseits (den Berufsforscher:innen). Dieses 20köpfige Ko-Forscher:innen-Team führte gemeinsam eine komplette wissenschaftliche Studie zu Alltagsproblemen im Leben mit Mukoviszidose durch, also von der Bestimmung des konkreten Forschungsthemas und -designs über die Datenerhebung und -auswertung bis hin zur Verwertung und Veröffentlichung der Ergebnisse. Zunächst wurde in einem diskursiven Prozess das Forschungsthema und -design entwickelt, mit folgendem Ergebnis: Ziel der gemeinsam konzipierten und durchgeführten patientenwissenschaftlichen Studie sollte es sein, erstmalig die typischen und wichtigsten Alltagsprobleme von Mukoviszidose-Betroffenen in Deutschland mittels einer Online-Befragung systematisch zu erfassen und im Hinblick auf ihre Bedeutung und den daraus entstehenden Unterstützungs- und Orientierungsbedarf zu analysieren. Die Ergebnisse dieser Online-Befragung, an der insgesamt 902 Betroffene (Patient:innen und Eltern betroffener Kinder) teilgenommen haben, werden in einem eigenen Berichtsband veröffentlicht und auf der oben verlinkten Projektseite zur Verfügung gestellt. Im vorliegenden Dokument geht es um die „Lessons Learned“ aus dem Forschungsprozess, also um die Erfahrungen und Erkenntnisse aus der Praxis des Pilotprojekts und um die Empfehlungen, die sich daraus für zukünftige Patient Science-Projekte ableiten lassen. Das Dokument richtet sich damit explizit an Praktiker:innen, Wissenschaftler:innen und Bürger:innen, die ein ähnliches bürgerwissenschaftliches Forschungsprojekt im Bereich Medizin und Gesundheitsforschung angehen wollen bzw. bereits durchführen