A mirror-Unet architecture for PET/CT lesion segmentation

Automatic lesion detection and segmentation from [${}^{18}$F]FDG PET/CT scans is a challenging task, due to the diversity of shapes, sizes, FDG uptake and location they may present, besides the fact that physiological uptake is also present on healthy tissues. In this work, we propose a deep learning method aimed at the segmentation of oncologic lesions, based on a combination of two UNet-3D branches. First, one of the network's branches is trained to segment a group of tissues from CT images. The other branch is trained to segment the lesions from PET images, combining on the bottleneck the embedded information of CT branch, already trained. We trained and validated our networks on the AutoPET MICCAI 2023 Challenge dataset. Our code is available at: https://github.com/yrotstein/AutoPET2023_Mv1

Relación entre los patrones de viabilidad, flujo miocárdico y la anatomía coronaria mediante tomografía por emisión de positrones integrada con tomografía multicorte

Introduccion La relacion entre la viabilidad, el flujo miocardico y el grado de estenosis epicardica en pacientes con enfermedad coronaria y disfuncion ventricular izquierda esta poco investigada. Objetivo Determinar si los patrones de viabilidad por tomografia por emision de positrones (PET) y el flujo miocardico en reposo se relacionan con el grado de estenosis epicardica. Material y metodos Se evaluo la viabilidad en 27 pacientes mediante el analisis combinado de la perfusion con 13N-amonio (13NH3) y el metabolismo con 18F-fluoro-2-desoxiglucosa (FDG) para identificar cuatro patrones PET: match (hipocaptacion concordante de ambos radiotrazadores), mismatch (hipoperfusion con captacion preservada de FDG), mismatch inverso (perfusion preservada e hipocaptacion de FDG) y perfusion/metabolismo conservados. El flujo absoluto se calculo mediante un modelo bicompartimental. Las estenosis se clasificaron en leves (< 50%), moderadas (> 50%), graves (> 70%) y criticas (. 90%). Resultados De 459 segmentos resultaron match el 33%, mismatch el 12%, mismatch inverso el 11% y conservado el 44%. El flujo para mismatch, mismatch inverso y conservado fue mayor que para los segmentos con match (p < 0,01). Quince lesiones fueron leves, 7 moderadas, 20 graves y 39 criticas. No hubo correlacion entre el grado de estenosis y los patrones de viabilidad (R < 0,2; p = ns) ni con los valores de flujo (R = 0,12). El analisis por territorio vascular no mostro correlacion con el grado de estenosis (p = ns). Conclusiones No hubo correlacion entre los patrones PET, el grado de estenosis epicardica y el flujo miocardico, lo que sugiere que la anatomia coronaria no puede discriminar miocardio viable del necrotico ni predecir el estado del flujo miocardico en pacientes con disfuncion ventricular izquierda

Optimization of oncological 18F-FDG PET/CT imaging based on a multiparameter analysis

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2016-05-12T19:05:36Z No. of bitstreams: 1 Menezes VO Optimization....pdf: 2748103 bytes, checksum: 8446733e75e4b2c0c251d96a9269ffdd (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2016-05-12T19:23:57Z (GMT) No. of bitstreams: 1 Menezes VO Optimization....pdf: 2748103 bytes, checksum: 8446733e75e4b2c0c251d96a9269ffdd (MD5)Made available in DSpace on 2016-05-12T19:23:57Z (GMT). No. of bitstreams: 1 Menezes VO Optimization....pdf: 2748103 bytes, checksum: 8446733e75e4b2c0c251d96a9269ffdd (MD5) Previous issue date: 2016São Rafael Hospital. Nuclear Medicine Department. Salvador, BA, Brasil / Universidade Federal de Pernambuco. Hospital das Clínicas. Nuclear Medicine Department. Recife, PE, BrasilSão Rafael Hospital. Nuclear Medicine Department. Salvador, BA, Brasil / Hospital das Clínicas da Universidade Federal de Bahia/Ebserh, Salvador 40110-060, BrazilSão Rafael Hospital. Nuclear Medicine Department. Salvador, BA, Brasil / Hospital Universitário Professor Alberto Antunes/Ebserh. Nuclear Medicine Department. Maceió, AL, BrasilUniversidade Federal de Sergipe. Department of Physics. São Cristóvão, SE, BrasilYale University School of Medicine. Department of Diagnostic Radiology. New Haven, Connecticut / University of Pisa. School of Engineering. Pisa, ItalyFundación Centro Diagnóstico Nuclear, Buenos Aires, ArgentinaSão Rafael Hospital. Centro de Biotecnologia e Terapia Celular. Salvador, BA, BrasilSão Rafael Hospital. Centro de Biotecnologia e Terapia Celular. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilPurpose: This paper describes a method to achieve consistent clinical image quality in 18F-FDG scans accounting for patient habitus, dose regimen, image acquisition, and processing techniques. Methods: Oncological PET/CT scan data for 58 subjects were evaluated retrospectively to derive analytical curves that predict image quality. Patient noise equivalent count rate and coefficient of variation (CV) were used as metrics in their analysis. Optimized acquisition protocols were identified and prospectively applied to 179 subjects. Results: The adoption of different schemes for three body mass ranges (90 kg) allows improved image quality with both point spread function and ordered-subsets expectation maximization-3D reconstruction methods. The application of this methodology showed that CV improved significantly (p < 0.0001) in clinical practice. Conclusions: Consistent oncological PET/CT image quality on a high-performance scanner was achieved from an analysis of the relations existing between dose regimen, patient habitus, acquisition, and processing techniques. The proposed methodology may be used by PET/CT centers to develop protocols to standardize PET/CT imaging procedures and achieve better patient management and cost-effective operations