Prostate
Body Thursday, 20 May 2021
Oral
813 - 822
Digital Poster
4085 - 4104

Oral Session - Prostate
Body
Thursday, 20 May 2021 16:00 - 18:00
  • CycleSeg: MR-to-CT Synthesis and Segmentation Network for Prostate Radiotherapy Treatment Planning
    Huan Minh Luu1, Gyu-sang Yoo2, Dong-Hyun Kim1, Won Park2, and Sung-Hong Park1
    1Magnetic Resonance Imaging Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of, 2Department of Radiation Oncology, Samsung Medical Center, Seoul, Korea, Republic of
    In this study, we proposed CycleSeg, a CycleGan-based network to produce synthetic CT images and organ segmentation for prostate cancer radiotherapy planning. Experiments showed that the network can generate realistic synthetic CT images and accurate segmentation.
    Figure 1: Architecture of CycleSeg, which is a combination of CycleGAN and 2 Unets. The notations in this figure correspond to those in Equation (1) in the text.
    Figure 4: Qualitative comparison of organ segmentation for a representative slice from the four networks (detail in text). The segmentation is displayed as contour.
  • Differential Diagnosis of  Prostate Cancer and Benign Prostatic Hyperplasia Based on Prostate DCE-MRI by Using Deep Learning with Different Peritumoral Areas
    Yang Zhang1,2, Weikang Li3, Zhao Zhang3, Yingnan Xue3, Yan-Lin Liu2, Peter Chang2, Daniel Chow2, Ke Nie1, Min-Ying Su2, and Qiong Ye3,4
    1Department of Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, United States, 2Department of Radiological Sciences, University of California, Irvine, CA, United States, 3Department of Radiology, The First Affiliate Hospital of Wenzhou Medical University, Wenzhou, China, 4High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
    deep learning, with appropriate consideration of the peritumoral information, can be implemented to analyze the DCE-MRI to differentiate between PCa and BPH.
    Figure 2: A case example from an 83-year-old man with prostate cancer (tPSA=7.13 ng/ml, Gleason Score=4+5). The lesion is manually outlined. (A) The first DCE time frame (pre-contrast image); (B) The 15th DCE time frame (post-contrast image); (C) The 40th DCE time frame (post-contrast image); (D) the DCE time intensity curve shows the wash-out kinetic pattern.
    Figure 4: Different ROIs from the case shown on Figure 2, which contains different amounts of peritumoral tissue as the input for the diagnostic neural network. (A) Original image, (B) Tumor alone (R0), (C) 120% enlarged tumor area (R2), (D) 150% enlarged tumor area (R3), (E) 5-pixel expansion from the tumor boundary (R4), (F) 10-pixel expansion from the tumor boundary (R5), (G) region growing with ±20% average intensity as the stopping criteria (R7), (F) region growing with ±30% average intensity as the stopping criteria (R8).
  • A Prior-Knowledge Embedded Convolutional Neural Network for Extracapsular Extension of the Prostate Cancer at Multi-Parametric MRI
    Yihong Zhang1, Ying Hou2, Jie Bao3, Yang Song1, Yu-dong Zhang2, Xu Yan4, and Guang Yang1
    1East China Normal University, Shanghai, China, 2the First Affiliated Hospital with Nanjing Medical University, Nanjing, China, 3the First Affiliated Hospital with Soochow University, Soochow, China, 4Siemens Healthcare, Shanghai, China
    We incorporated prior-knowledge into a CNN model to diagnosis ECE from mpMRI. Our model performed better than the classical CNN model and clinical reports on both the internal and external test cohorts.
    Figure 1 The workflow of the research. We trained the PAGNet on training cohort from one-site, and evaluated its performance with cohorts from both institutions. The performance of the proposed model was compared with those of a ResNeXt model and two radiologists.
    Figure 4 ROC curves (top) and Grad-CAM of PAGNet (bottom). PAGNet performed better than ResNeXt model and clinical reports in the internal test cohort (a), and achieved results comparable to the radiologists on the external cohort (b). The Grad-CAMs of the model on one positive case (c) and one negative case (d) were also shown, in which the red regions indicate where the model paid attention.
  • Prostate Cancer Detection on T2-weighted MR images with Generative Adversarial Networks
    Alexandros Patsanis1, Mohammed R. S. Sunoqrot 1, Elise Sandsmark 2, Sverre Langørgen 2, Helena Bertilsson 3,4, Kirsten M. Selnæs 1,2, Hao Wang5, Tone F. Bathen 1,2, and Mattijs Elschot 1,2
    1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology - NTNU, Trondheim, Norway, 2Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 3Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology - NTNU, Trondheim, Norway, 4Department of Urology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 5Department of Computer Science, Norwegian University of Science and Technology - NTNU, Gjøvik, Norway
    Weakly-supervised GANs trained on normalized, randomly sampled images of size 128x128 with a 0.5 mm pixel spacing gave the best AUC for detection of prostate cancer on T2-weighted MR images.
    Figure 1: The proposed end-to-end pipeline includes automated intensity normalization using AutoRef5, automated prostate segmentation using VNet6 and nnU-Net7 followed by an automated Quality Control step, and the sampling of cropped images with different techniques and settings. The cropped images were then used to train weakly-supervised (Fixed-Point GAN) and unsupervised GAN (f-AnoGAN) models.
    Figure 3: f-AnoGAN and Fixed-Point GAN - 3.a) f-AnoGAN: Linear latent space interpolation for random endpoints of trained f-AnoGAN shows that the model does not focus only on one part of the training dataset. 3.b) f-AnoGAN: Mapping from image space (query) back to GAN's latent space should yield resembled images. Here, the mapped images are similar but not entirely identical. 3.c) f-AnoGAN: Positive test case that fails– 3.d) Fixed-Point GAN: negative and positive tested cases, no differences for the negative case, whereas positive case found, and localized (difference).
  • Texture-Based Deep Learning for Prostate Cancer Classification with Multiparametric MRI
    Yongkai Liu1,2, Haoxin Zheng1, Zhengrong Liang3, Miao Qi1, Wayne Brisbane4, Leonard Marks4, Steven Raman1, Robert Reiter4, Guang Yang5, and Kyunghyun Sung1
    1Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Physics and Biology in Medicine IDP, University of California, Los Angeles, Los Angeles, CA, United States, 3Departments of Radiology and Biomedical Engineering, Stony Brook University, Stony Brook, New York, NY, United States, 4Department of Urology, University of California, Los Angeles, Los Angeles, CA, United States, 5National Heart and Lung Institute, Imperial College London, London, United Kingdom
    We presented a textured-based deep learning method to enhance prostate cancer classification performance by enriching deep learning with prostate cancer texture information.
  • Incorporating UDM into Deep Learning for better PI-RADS v2 Assessment from Multi-parametric MRI
    Ruiqi Yu1, Ying Hou2, Yang Song1, Yu-dong Zhang2, and Guang Yang1
    1Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China, 2Department of Radiology, the First Affiliated Hospital with Nanjing Medical University, Jiangsu, China
    For PI-RADS v2 assessment, the proposed CNN model with UDM achieved an F1 score of 0.640 and achieved an accuracy of 64.4% on an independent validation cohort.
    Figure 1. The overview of the ResNet-UDM. The output of ResNet50 was continuous and would be discretized with three self-learnt . The discrete output was than compared with the ground truth. In the Inference stage, were also used to discretize the output of ResNet50 and produce the final PI-RADS category.
    Table 1. The comparison of ResNet-UDM and S. Thomas’s work.
  • Explainable AI for CNN-based Prostate Tumor Segmentation in Multi-parametric MRI Correlated to Whole Mount Histopathology
    Deepa Darshini Gunashekar1, Lars Bielak1,2, Arnie Berlin3, Leonard Hägele1, Benedict Oerther4, Matthias Benndorf4, Anca Grosu2,4, Constantinos Zamboglou2,4, and Michael Bock1,2
    1Dept.of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany, 2German Cancer Consortium (DKTK), Partner Site Freiburg, Freiburg, Germany, 3The MathWorks, Inc., Novi, MI, United States, 4Dept.of Radiology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
    An explainable deep learning model was implemented to interpret the predictions of a convolution neural network (CNN) for prostate tumor segmentation. The model achieves better visual performance and fairness for interpreting the decision-making process of the CNN.

    Segmentation of PG and GTV for test patient 1 - 3 (a) Input mpMRI sequences, (b) ground truth, (c) prediction. Overlays in (b) and (c) depict PG in blue and GTV in red.(d-e) overlay of the saliency map for the class PG and GTV on the corresponding input sequences and (f) the generated saliency map PG and GTV. The locations of higher intensity values in the saliency map indicate the importance of the corresponding voxels in the prediction of CNN.

    DSC for Test cohort (n = 15). The red lines in the plot show the median Dice value for the classes BG, GTV and PG. The upper and lower bounds of the blue box indicate the 25th and 75th percentiles, respectively.
  • Prostate Lesion Segmentation on VERDICT-MRI Driven by Unsupervised Domain Adaptation
    Eleni Chiou1,2, Francesco Giganti3,4, Shonit Punwani5, Iasonas Kokkinos2, and Eleftheria Panagiotaki1,2
    1Centre of Medical Image Computing, University College London, London, United Kingdom, 2Department of Computer Science, University College London, London, United Kingdom, 3Department of Radiology, UCLH NHS Foundation Trust, University College London, London, United Kingdom, 4Division of Surgery & Interventional Science, University College London, London, United Kingdom, 5Centre for Medical Imaging, Division of Medicine, University College London, London, United Kingdom

    We utilize pixel-level unsupervized adaptation for lesion segmentation on VERDICT-MRI. Using the proposed approach we obtain segmentation performance which is close to the one obtained when we train using full supervision on VERDICT-MRI.

    Figure 1. The image-to-image translation network translates DW-MRI data from mp-MRI acquisitions to VERDICT-MRI. GAN-type losses are used to generate realistic VERDICT-MRI data from DW-MRI form mp-MRI acquisitions while standard cycle-consistency losses allow us to preserve the content during the translation. A segmentation loss on the cycle-reconstructed images obtained using a pre-trained source-domain network, ensures that critical structures corresponding to the prostate lesions are successfully preserved.
    We translate the DW-MRI from mp-MRI acquisitions to VERDICT-MRI and supervise using the ground-truth segmentation masks.
  • Accelerated Diffusion-Relaxation Correlation Spectrum Imaging (DR-CSI) for Ex Vivo and In Vivo Prostate Microstructure Mapping
    Zhaohuan Zhang1, Sohrab Afshari Mirak1, Melina Hosseiny1, Afshin Azadikhah1, Amirhossein Mohammadian Bajgiran1, Alan Priester2, Kyunghyun Sung1, Anthony Sisk3, Robert Reiter2, Steven Raman1, Dieter Enzmann1, and Holden Wu1
    1Department of Radiological Sciences, UCLA, Los Angeles, CA, United States, 2Department of Urology, UCLA, Los Angeles, CA, United States, 3Department of Pathology, UCLA, Los Angeles, CA, United States
    Using a data-driven systematic framework to select subsampling schemes, we demonstrated ~60% reduction in scan time for prostate DR-CSI while maintaining accurate prostate microstructure parameter estimation. This framework may benefit design of accelerated DR-CSI for PCa diagnosis.
    Figure 3: (a) Evaluation of subsampled TE-b schemes for ex vivo prostate DR-CSI. For a fixed total encoding number, each TE-b scheme was compared to the reference 4x7 scheme in terms of the mean total spectrum error (TSpE) in 9 prostates. (b) Selected schemes with the minimum mean TSpE (c) Slice-averaged T2-D spectra and signal component fraction maps from each schemes. The definitions of the three spectral peaks are indicated on the reference T2-D spectrum. The prostate cancer region of interest (transition zone) is denoted by the black contour on the reference (fA,, fB, fC) maps.
    Figure 5: (a) Evaluation of subsampled TE-b schemes for in vivo prostate DR-CSI. For a fixed total encoding number, each TE-b scheme was compared to the reference 5x4 scheme in terms of the mean total spectrum error (TSpE) . (b) Slice-averaged T2-D spectra and signal component fraction maps from each selected schemes. The definitions of the four spectral peaks are indicated on the reference T2-D spectrum (c) Evaluation of signal component fraction estimates in the overall prostate peripheral zone (PZ) and transition zone (TZ). compared to reference
  • Characterization of motion-induced phase errors in prostate DWI
    Sean McTavish1, Anh T. Van2, Kilian Weiss3, Johannes M. Peeters4, Marcus R. Makowski2, Rickmer F. Braren2, and Dimitrios C. Karampinos2
    1Technical University of Munich, Munich, Germany, 2Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany, 3Philips Healthcare, Hamburg, Germany, 4Philips Healthcare, Best, Netherlands
    Both the constant and linear phase terms vary periodically with breathing motion confirming the hypothesis that respiratory is the main source of motion-induced phases. The main contribution to the phase error in the prostate is the constant phase term across diffusion encoding directions.
    Figure 1: Shown here is the cine acquisition in the sagittal plane. It can be seen that as the subject breathes, the prostate also moves by a small amount with the breathing motion, especially along the feet/head direction.
    Figure 3: Shown here are the power spectra for the axial scan with diffusion in the S/I direction. The linear phase is being measured in the A/P and R/L directions. The constant phase, linear phase in the A/P direction and the residual phase after subtracting the linear and constant phases show frequency peaks at similar frequencies to the breathing curve. Note that the values around 0 of each power spectrum were removed prior to calculating the normalized power, which was found by taking the square root of the sum of squares of the power spectrum.
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Digital Poster Session - Prostate: Methods
Body
Thursday, 20 May 2021 17:00 - 18:00
  • Directional and Inter-acquisition Variability in DWI (DAVID)
    Jay M. Pittman1,2, Aritrick Chatterjee1,2, Teodora Szasz3, Grace Lee1,2, Mihai Giurcanu4, Milica Medved1,2, Ambereen Yousuf1,2, Ajit Devaraj5, Aytekin Oto1,2, and Gregory S. Karczmar1,2
    1Radiology, The University of Chicago, Chicago, IL, United States, 2Sanford J. Grossman Center of Excellence in Prostate Imaging and Image Guided Therapy, The University of Chicago, Chicago, IL, United States, 3Research Computing Center, The University of Chicago, Chicago, IL, United States, 4Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States, 5Philips Research North America, Cambridge, MA, United States
    Standard averaging of multiple acquisitions for high b-values in DWI can obscure cancers, due to very large inter-acquisition variability. We propose alternatives, including ‘Editing for Restricted Diffusion’, to improve diagnostic accuracy. 
    Figure 1. (A) Mean DW Image (900 sec/mm2) of patient 6. (B) Standard deviation per voxel image for patient 6. (C) Mean signal intensity versus acquisition # divided into three diffusion-sensitizing gradient directions (Black line = mean, Dashed error bar = margin of error, Dashed gray line = range). White arrow points to cancerous lesion while red arrow points to noise.
    Table 1. Mean Signal, % Range, and SNR of patients 1-7 for a 3x3 region of voxels in cancerous and benign contralateral tissue.
  • Multi-Readout Diffusion-Weighted Imaging for Studying Coupling between Apparent Diffusion Coefficient and Echo Time
    Kaibao Sun1, Guangyu Dan1,2, Zheng Zhong1,2, and Xiaohong Joe Zhou1,2,3
    1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Departments of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States
    A novel multi-readout DWI sequence was capable of acquiring multiple diffusion-weighted images at different TEs in a single scan. This sequence was used to reveal the coupling between ADC and TE in the healthy and neoplastic prostate tissues.
    Figure 1: (A): A diagram of the multi-readout DWI sequence. Multiple EPI echo-trains (or readout trains) are incorporated into the sequence, with each echo-train corresponding to a specific effective TE. (B): In the multi-readout DWI sequence, signal excitation is accomplished by a 2D RF pulse to restrict the FOV so that a shorter echo train length can be used in each echo-train, allowing multiple echo-trains to be acquired.
    Figure 4: ADC maps of the prostate at different TEs overlaid onto the corresponding T2*-weighted images (b-value of 0 s/mm2) of a healthy subject (top row, average values: 1.49, 1.58, and 1.67 μm2/ms) and a patient with prostate cancer (bottom row, average values: 1.35, 1.39, and 1.45 μm2/ms). The red arrow indicates the focal region of the cancer.
  • Synthetic DWI in prostate
    Yu Ueda1, Tsutomu Tamada2, Makoto Obara1, Tetsuo Ogino1, Daisuke Morimoto-Ishikawa3, Hiroyasu Sanai2, Koji Yoshida2, Ayumu Kido2, Tomoko Hyodo4, Kazunari Ishii4, Masami Yoneyama1, and Marc Van Cauteren5
    1Philips Japan, Tokyo, Japan, 2Department of Radiology, Kawasaki Medical School, Okayama, Japan, 3Radiology Center, Kindai University Hospital, Osaka, Japan, 4Department of Radiology, Kindai University, Osaka, Japan, 5BIU MR Asia Pacific, Philips Healthcare, Tokyo, Japan
    Synthetic DWI at b = 1000 s/mm2 (DWI1000) with shorter TR of 1000ms had a tendency to show better contrast than conventional DWI1000 with long TR of 6000ms.
    Figure 2. Prostate cancer in transitional zone. Cancer lesion is shown as a homogeneous hypointense lesion with mass effect on T2WI (arrow). synDWI1000 with shorter TR provided better contrast than DWI1000 with long TR, whereas noise in synDWI1000 with TR of 500ms become more visible.
    Figure 4. CR (a) and visual score (b) of prostate cancer between synDWI1000 with shorter TR of 1000ms and DWI1000 with long TR of 6000ms in three patients.
  • Rapid fitting of Luminal Water Fraction in Prostate MRI
    David Atkinson1, Fiona Gong1, Giorgio Brembilla1, and Shonit Punwani1
    1Centre for Medical Imaging, University College London, London, United Kingdom
    Two potential metrics are presented; the mean signal from later echoes, normalized to the median from the first echo, and, a bi-exponential fit using fixed T2s of 50 and 300ms. Initial presentation of results suggests these methods are fast and should be evaluated for clinical efficacy.
    Fig 3. Images from three representative subjects.
    Fig 2. Alternative fits to the same voxel. Note the fitted signals (top row) are similar but the T2 distributions (lower row) differ. LWF maps inset.
  • Prostate MRI at 3-T: clinical impact of ultra-high b value (3,000 s/mm2) diffusion-weighted MR imaging compared to high b value of 2,000 s/mm2
    Ayumu Kido1, Tsutomu Tamada1, Yu Ueda2, Masami Yoneyama2, and Akira Yamamoto1
    1Radiology, Kawasaki Medical School, Okayama, Japan, 2Philips Japan, Tokyo, Japan
    Compared with high b value DWI (b2000), ultra-high b value DWI (b3000) could not contribute to increased diagnostic performance in prostate cancer.
    Prostate cancer lesion is shown as a homogeneous hypointense lesion with mass effect on T2-weighted imaging (arrow) (A) and focal early enhancement on dynamic contrast-enhanced MR imaging (arrow) (B). Signal intensity of normal prostate is lower in b3000 (D) than in b2000 (C). However, the lesion conspicuity between b2000 (arrow) and b3000 (arrow) is almost equivalent.
  • Automated patient-level detection of grade group ≥2 prostate cancer using quantitative restriction spectrum imaging MRI
    Allison Y Zhong1, Leonardino A Digma1, Troy Hussain1, Christine H Feng1, Christopher C Conlin2, Karen Tye1, Asona J Lui1, Maren MS Andreassen3, Ana E Rodríguez-Soto2, Roshan Karunamuni1, Joshua Kuperman2, Rebecca Rakow-Penner2, Michael E Hahn2, Anders M Dale2,4, and Tyler M Seibert1,2,5
    1Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, CA, United States, 2Department of Radiology, University of California San Diego, La Jolla, CA, United States, 3Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, 4Department of Neurosciences, University of California San Diego, La Jolla, CA, United States, 5Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
    RSI-MRI performed well as a quantitative classifier of higher-grade prostate cancer in a retrospective series, with superior detection compared to conventional ADC and comparable performance to expert PI-RADS interpretation.
    Figure 2. Receiving operator characteristic (ROC) curves for conventional ADC (dark gray), RSI-C1 (green), and PI-RADS v2.x (light gray), for the patient-level detection of higher-grade prostate cancer.
    Figure 1. Histograms of (A) conventional ADC (lowest voxel value in prostate), (B) RSI-C1 (highest voxel value in prostate), and (C) highest PI-RADS category (v2 prior to 2019, v2.1 in 2019). Blue: Patients with no cancer or low-grade cancer. Orange: Patients with higher-grade (grade group ≥2) prostate cancer. Brown: where blue and orange overlap.
  • Comparison of single-shot EPI DWI, multi-shot EPI DWI, and single-shot EPI DWI using Compressed SENSE framework in prostate
    Ayumu kido1, Tsutomu Tamada1, Yu Ueda2, Masami Yoneyama2, Jaladhar Neelavalli3, and Akira Yamamoto1
    1Kawasaki Medical School, Okayama, Japan, 2Philips Japan, Tokyo, Japan, 3Philips India, Bangalore, India
    Single-shot EPI (sshEPI) DWI has comparable the diagnostic performance of PC equivalent to sshEPI DWI using C-SENSE and multi-shot EPI (mshEPI) DWI called IRIS, whereas sshEPI DWI using C-SENSE and IRIS improve the image distortion and image blurringcompared to sshEPI DWI.
    Details of the imaging parameters
    A 80-year-old male with prostate cancer (PSA level of 13.69 ng/mL, Gleason score of 3+4) in the transitional zone. Cancer lesion is shown as a homogeneous hypointense lesion with mass effect on T2-weighted imaging (A). The lesion with focal hyperintensity is depicted clearly in the three DWI image (sshEPI DWI, sshEPI DWI using C-SENSE, and IRIS) (B, C and D). SNR and CNR is higher in sshEPI DWI than in sshEPI DWI using C-SENSE and IRIS, whereas sharpness in sshEPI DWI using C-SENSE and IRIS is better than sshEPI DWI.
  • Clinical application of single-shot echo-planer diffusion-weighted imaging with compressed SENSE in prostate MRI
    Ayumu Kido1, Tsutomu Tamada1, Yu Ueda2, Masami Yoneyama2, and Akira Yamamoto1
    1Radiology, Kawasaki Medical School, Okayama, Japan, 2Phillips Japan, Tokyo, Japan
    DWI with single-shot EPI (ssEPI) suffers from low SNR in high b-value acquisition. Compressed SENSE (C-SENSE) allow for a reduction of the noise. Compared with ssEPI with SENSE, ssEPI and C-SENSE may contribute improved image quality and risk stratification in prostate cancer.
    Details of the imaging parameters
    A 82-year-old male with prostate cancer (PSA level of 6.56 ng/mL, Gleason score of 4+3) in the right peripheral zone. Cancer lesion is shown as a homogeneous hypointense lesion with mass effect on T2-weighted imaging (A). The lesion with focal hyperintensity is depicted clearly in the both DWI image (ssEPIS and EPICS) (B, C). Signal to noise ratio is higher in EPICS than in EPIS.
  • Characterization of prostate cancer and benign prostatic hyperplasia using IVIM-DKI with parameter-reconstruction method
    Archana Vadiraj Malagi1, Virender Kumar2, Kedar Khare3, Chandan J. Das4, and Amit Mehndiratta1,5
    1Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India, 2Department of Nuclear Magnetic Resonance (NMR),, All India Institute of Medical Sciences Delhi, New Delhi, India, 3Department of Physics, Indian Institute of Technology Delhi, New Delhi, India, 4Department of Radiodiagnosis, All India Institute of Medical Sciences Delhi, New Delhi, India, 5Department of Biomedical Engineering, All India Institute of Medical Sciences Delhi, New Delhi, India
    IVIM-DKI model with total variation(TV) penalty function reduced non-physiological inhomogeneity in IVIM-DKI parameter adaptively to produce better quality parameter maps. D, f, k can be used discriminate between PCa and BPH with high diagnostic performance.
    Figure2 For BPH (yellow), the hyperintense region was observed on (b) ADC, (c) D, and (e) f; whereas hypointense region was observed on, (a) High b-value map, (d) D*, and (f) k of a representative patient diagnosed with PCa and BPH.
    Figure4 Diagnostic performance of IVIM-DKI parameters obtained from HY and HY+TV model to differentiate from (a) Tumor vs BPH and (b) Tumor vs Healthy PZ.
  • Comparison of multiplexed sensitivity encoding (MUSE) and single-shot echo-planar imaging (ssEPI) for  diffusion-weighted imaging of prostate
    Chun-Ying Shen1, Chia-Wei Li2, Chien-Yuan Lin2, and Ching-Hua Yang1
    1Department of Radiology, Taovuan General Hospital, Ministry of Health and Welfare, Taovuan, Taiwan, 2GE Healthcare, Taipei, Taiwan
    This study aimed to evaluate and compare the SNR and distortion of multiplexed sensitivity encoding (MUSE) and conventional imaging for diffusion-weighted imaging of the prostate. Our result showed that prostate images by MUSE-DWI can provide significant less distortions and higher SNR.
    Figure 1. The diffusion-weighted images of prostate by ssEPI-DWI and MUSE-DWI.
    Figure 2. The data analysis procedure. (a) The prostate ROI was segmented manually from high-resolution structural images, and (b) the overlapping between the segmented prostate ROI and prostate range by DWI images was calculated.
  • Optimal 2D-ROI Method to Measure Apparent Diffusion Coefficient of Lesions in Prostate MRI
    Hiroaki Takahashi1, Kotaro Yoshida2, Akira Kawashima3, Num Ju Lee4, Adam T Froemming4, Daniel A Adamo4, Ashish Khandelwal4, Candice W Bolan5, Matthew T Heller6, Robert P Hartman4, Bohyun Kim4, Kenneth A Philbrick4, Rickey E Carter5, Lance A Mynderse4, Mitchell R Humphreys6, and Naoki Takahashi4
    1Department of Radiology, Mayo Clinic, Rochester, Rochester, MN, United States, 2Department of Diagnostic Radiology, Kanazawa University School of Medical Science, Kanazawa, Japan, 3Department of Radiology, Mayo Clinic, Arizona, Scottsdale, AZ, United States, 4Mayo Clinic, Rochester, Rochester, MN, United States, 5Mayo Clinic, Florida, Jacksonville, FL, United States, 6Mayo Clinic, Arizona, Scottsdale, AZ, United States
    The optimal method for measuring ADC values for differentiating csPCa and non-csPCa on prostate MRI are 2D-ROI placed on the lowest ADC area using 6-8 mm2.
    Fig.1. A dot plot of AUC values of receiver operating characteristics in differentiation of presence or absence of clinically significant prostate cancer for 2D-small-ROI with different area
    Fig.5. Bland-Altman plots of ADC values measured by using 3D-whole-lesion-ROI method (10th percentile). 95% limits of agreement among the readers on was +/-112.
  • Application of High Spectral and Spatial resolution (HiSS) MRI in prostate: a pilot study
    Milica Medved1,2, Aritrick Chatterjee1,2, Ajit Devaraj3, Carla Harmath1, Grace Lee1, Ambereen Yousuf1,2, Tatjana Antic4, Aytekin Oto1,2, and Gregory S Karczmar1,2
    1Radiology, The University of Chicago, Chicago, IL, United States, 2Sanford J. Grossman Center of Excellence in Prostate Imaging and Image Guided Therapy, The University of Chicago, Chicago, IL, United States, 3Philips Research NA, Cambridge, MA, United States, 4Pathology, The University of Chicago, Chicago, IL, United States
    HiSS MRI is feasible for prostate cancer imaging at 3T, without an endorectal coil. HiSS parameters describing the water resonance shape are complementary to standard multi-parametric MRI and can likely be used to increase diagnostic accuracy.
    Figure 2: The T2-weighted image, ADC map, shortest-TE HiSS MRI image, and HiSS MRI-derived temporal domain (R, R1, R2) and spectral domain (PW, PRD, PRA) parameter maps are shown here for a representative slice through the prostate of a 52-yo man with a Gleason score 7 (3+4) lesion (white outline).
    Figure 3: Boxplots of HiSS MRI-derived parameters R, R1, R2, PW, PRD, and PRA are shown, for normal and cancer ROIs. The whiskers represent the full data range. All HiSS-derived parameters were statistically significantly different (p < 0.05) between cancer and normal tissue ROIs, except R2.
  • Non-Invasive Prostate Metabolic and Cytometric Imaging: Insights from Activity MRI [aMRI]
    Xin Li1, Eric M. Baker1, Brendan Moloney1, Ryan P. Kopp2, Fergus V. Coakley3, Mark G. Garzotto4, and Charles S. Springer1
    1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 2Urology, Oregon Health & Science University, Portland, OR, United States, 3Radiology, Oregon Health & Science University, Portland, OR, United States, 4Urology, Portland VA Center, Portland, OR, United States
    The first metabolic and cytometric maps of human prostate cancer are presented.  A Gleason (3+4) tumor has very conspicuous elevated cell density and reduced average cell density, and depressed homeostatic Sodium Pump enzymatic turnover. 

    Figure 1. Prostate axial ADC (a), ρ (b), V (c), and kio (d) maps; inferior perspective. The GS (3+4) lesion is bordered in yellow (a). [Pixels in urethra and ductule-rich regions are colored black in (b), (c), and (d).] The ρ, V, maps are in near absolute quantitative agreement with estimations from published ex vivo histopathology and the r map shows very high in vivo lesion/NA prostate gland conspicuity. The kio map indicates lower metabolic activity in the lesion. The r and V maps may suggest nascent pathology in NA prostate regions, particularly the peripheral zone (see text).


  • Differential diagnosis of PCa and BPH using intratumoral susceptibility signal intensities based onESWAN
    Yunsong Liu1, Hongkai Wang2, Mingrui Zhuang2, Lihua Chen1, Qingwei Song1, Shuang Meng1, and Ailian Liu1
    1The First Affiliated Hospital of Dalian Medical University, Dalian, China, 2Dalian University of Technology, Dalian, China
    The study demonstrated that quantitative ITSS had good diagnostic efficiency to differentiate PCa and BPH. In the present study, we proposed that ITSS could be a promising imaging biomaker that allow differentiate PCa and BPH quantitatively and automatically.
    ROI can be obtained without layer-by-layer annotation through the interpolation and annotation tools of AS
    De-artifacting workflow
  • ­­­­Physically Implausible Diffusion Signals (PIDS) as a Quality Assessment Metric in Prostate DWI
    Teodora Szasz1, Milica Medved2, Aritrick Chatterjee2, Ajit Devaraj3, Ambereen Yousuf2, Xiaobing Fan2, Gregory Karczmar2, Aytekin Oto2, and Grace Lee2
    1Research Computing Center, The University of Chicago, Chicago, IL, United States, 2Department of Radiology, The University of Chicago, Chicago, IL, United States, 3Philips Research North America, Chicago, IL, United States
    PIDS levels were similar for non-endorectal coil (NERC) and endorectal coil cohorts (ERC). Rician noise was higher and strongly correlated with PIDS in NERC compared to ERC. High PIDS coincided with motion artifacts and low signal. It can be used as quantitative marker for quality in prostate.
    Table 1. Average PIDS prevalence across the 40 ERC and 40 NERC subjects.
    Figure 1. Example of variations of the PIDS across TZ and PZ. A high PIDS value of 40% can be seen in the TZ region (a) and (b), while in PZ region the PIDS is 9.6%. Similarly, in another subject we can see a higher value of PIDS (33%) in PZ - (c) and (d), compared to TZ.
  • POST-ACQUISITION WATER SIGNAL REMOVAL IN 3D WATER-UNSUPPRESSED 1H-MR SPECTROSCOPIC IMAGING DATA OF THE PROSTATE
    Angeliki Stamatelatou1, Diana Sima2, Sabine Van Huffel3, Sjaak Van Asten4, Arend Heerschap4, and Tom Scheenen4
    1Radiology, Radboud UMC, Nijmegen, Netherlands, 2Icometrix, Leuven, Belgium, 3KU Leuven, Leuven, Belgium, 4Radboud UMC, Nijmegen, Netherlands
    Water signal removal in 3D water-unsuppressed 1H-MRSI data of the prostate is presented. Löwner BSS and HLSVD methods were compared against conventional MRSI water suppression. Post-acquisition water removal was successfully implemented, and the Löwner filter showed the best performance.
    Figure 1. MRS prostate spectra from a volunteer in the frequency range 1.5 ppm to 5.5 ppm. a. Spectrum obtained with water signal suppression b. Spectrum obtained without water signal suppression but with water signal removal using a Löwner filter, c. Spectrum without water signal suppression but with water signal removal using a HLSVD filter.
    Table 2. Mean values of the absolute metabolite concentrations of citrate and choline. The bottom row presents absolute metabolite tissue concentrations reported in reference 7. The choline values seem to be lower compared to the literature, but this is explained by the fact that the volunteers participated in the study were of a young age.
  • Standardization of SE-MRE at 3.0T for the prostate.
    Nicolás Moyano Brandi1,2,3, Daniel Fino1,2,4, Joaquín Capó1,2,3, Federico González1,4,5, Bruno Lima1,2, Maximiliano Noceti1,2,6, Pablo Ariza1,2, and Andrés Dominguez1,2
    1Magnetic Resonance, Fundacion Escuela de Medicina Nuclear, Mendoza, Argentina, 2Magnetic Resonance, Fundación Argentina para el Desarrollo en Salud, Mendoza, Argentina, 3Universidad de Mendoza, Mendoza, Argentina, 4Universidad Nacional de Cuyo, Mendoza, Argentina, 5Comisión Nacional de Energía Atómica, Mendoza, Argentina, 6Hospital Italiano, Mendoza, Argentina
    A cut-off value between PR-1/2 and PR-4/5 of 4.4 kPa was determined. Regarding the results with MRE-SE, the cut-off value of 4.4 kPa makes it possible to establish that trans-pelvic prostate MRE is a method capable of differentiating malignant tissue from normal tissue.
    Wave propagation map, MRE (0-8 kPa) and MRE confidence map (0-8 kPa).
    Left: SE-MRE 60 Hz. Right: GRE-MRE 60 Hz.
  • Development of Distortion-Free MR Elastography Methods for Slip Interface Imaging of the Prostate
    Yi Sui1, Kay Pepin1, Phillip J. Rossman1, Kevin Glaser1, Lance Mynderse2, Richard L. Ehman1, and Ziying Yin1
    1Radiology, Mayo Clinic, Rochester, MN, United States, 2Urology, Mayo Clinic, Rochester, MN, United States
     A distortion-free technique has been developed for prostate MR elastography (MRE) slip-interface imaging (SII) . This new technique may be useful for evaluating the degree of prostate extraprostatic extension (EPE) noninvasively.
    Figure 2. Distortion-free DIADEM-MRE magnitude image and SII-derived OSS map from the same healthy volunteer.
    Figure 1: Standard EPI-MRE magnitude image, distortion-free DIADEM-MRE magnitude image, and T2-weighted anatomical image from a healthy volunteer
  • Investigate the correlation between APT valuesand ADCs in Benign Prostatic Hyperplasia and Prostatic Cancer
    Shuang Li1, Ailian Liu1, Lihua Chen1, Yuanfei Li1, Shuang Meng1, Jiazheng Wang2, Peng Sun2, Qingwei Song1, and Renwang Pu1
    1The First Affiliated Hospital of Dalian Medical University, Dalian, Dalian, China, 2Philips Healthcare, Beijing, China, Beijing, China
     Both APT and ADC values show a statistical difference between patients with PCa and BPH. There is a moderate negative correlation between the APT and ADC values in PCa and BPH.
    Figure 1 T2WI(A)image, DWI(B)image, fused APT and DWI (C, D) images of a BPH patient. T2WI(E)image, DWI(F)image, fused APT and DWI (G, H) images of a PCa patient. The placement of ROIs is as illustrated.
    Table 2.Comparisonof APT and ADC values
  • Optimization of 3D prostate APTw MR imaging
    Wenjun HU1, Ailian Liu1, Lihua Chen1, Zhiwei Shen2, Jiazheng Wang3, Yi Zhang4, and Qingwei Song1
    1The First Affiliated Hospital of Dalian Medical University, Dalian, China, 2Philips Healthcare, Beijing, China, 3Philips Healthcare, Bejing, China, 4Zhejiang University, Hangzhou, China
    Higher SNR and more clear anatomical structure of APTw images in prostate was acquired with the optimal scan parameters: the number of slices of 7, voxel of 2×2 mm2, the echo train length of 100, small FOV of 130×100×49mm3, fold-over suppression of rest, SENSE of 1.1, phase encoding direction of AP.
    Table 1. Scan parameters of APTw sequence in group A with the default parameters and group B with the optimal parameters
    Figure2. a 75-year-old male with BPH of group B. T2WI(2a), DWI (2b), M0 (2c) (central zone SNR=71.22, peripheral zone SNR=22.12), APTw (2d) images are shown.
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Digital Poster Session - Prostate: Deep Learning
Body
Thursday, 20 May 2021 17:00 - 18:00
  • The repeatability of deep learning-based segmentation of the prostate, peripheral and transition zones on T2-weighted MR images
    Mohammed R. S. Sunoqrot1, Kirsten M. Selnæs1,2, Elise Sandsmark2, Sverre Langørgen2, Helena Bertilsson3,4, Tone F. Bathen1,2, and Mattijs Elschot1,2
    1Department of Circulation and Medical Imaging, NTNU, Norwegian University of Science and Technolog, Trondheim, Norway, 2Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 3Department of Cancer Research and Molecular, NTNU, Norwegian University of Science and Technolog, Trondheim, Norway, 4Department of Urology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
    The repeatability of the best-performing deep learning-based prostate segmentation methods is comparable to that of manual segmentations, which is important for clinical applications based on multiple scans in time, such as active surveillance.
    Figure 1 The middle slice for the whole prostate, apex and base of a randomly selected case segmented (peripheral zone (PZ) and transition zone (TZ)) by different approaches for scan 1 and 2.
    Figure 3 The single score intra-class correlation coefficient (ICC) of the shape features extracted from the whole prostate gland (WP), peripheral zone (PZ) and transition zone (TZ) for the investigated methods. The methods connected with (-) were significantly different. In both manual and DL-based segmentations, Elongation, Flatness and Sphericity had a remarkably lower ICC than the other features in WP and TZ.
  • Assessing the variability of contours performed by DL algorithms in prostate MRI
    Jeremiah Sanders1, Henry Mok2, Alexander Hanania3, Aradhana Venkatesan4, Chad Tang2, Teresa Bruno2, Howard Thames5, Rajat Kudchadker6, and Steven Frank2
    1Imaging Physics, UT MD Anderson Cancer Center, Houston, TX, United States, 2Radiation Oncology, UT MD Anderson Cancer Center, Houston, TX, United States, 3Radiation Oncology, Baylor College of Medicine, Houston, TX, United States, 4Diagnostic Radiology, UT MD Anderson Cancer Center, Houston, TX, United States, 5Biostatistics, UT MD Anderson Cancer Center, Houston, TX, United States, 6Radiation Physics, UT MD Anderson Cancer Center, Houston, TX, United States
    Spatial entropy clusters with the highest entropy were located around the circumference of the prostate, especially at junctions between the target and surrounding OARs (bladder neck, prostate-SV junction, region along prostate and rectal wall,  prostate apex-EUS junction).
    Figure 2. Spatial entropy maps for human and computer observer populations in 8 example patients. Spatial entropy maps were computed by first grouping the predictions from DL models trained with the same loss function. Four loss functions were investigated including crossentropy, DSC, Jaccard, and focal.
    Figure 3. Autocontouring predictions (prostate: thick white line, OARs: blue lines) displayed with spatial entropy maps (transparent regions; yellow–30% of max entropy, orange-70% of max entropy, red-90% of max entropy) overlaid on post-implant prostate MRIs in a commercial treatment planning system. Arrows indicate regions of high spatial entropy clusters at organ junctions where physicians can review and potentially refine the automated predictions.
  • Few-shot Meta-learning with Adversarial Shape Prior for Zonal Prostate Segmentation on T2 Weighted MRI
    Han Yu1, Varut Vardhanabhuti1, and Peng Cao1
    1The University of Hong Kong, Hong Kong, Hong Kong
    We propose a novel gradient-based meta-learning scheme to tackle the challenges when deploying the model to a different medical center with the lack of labeled data. Evaluation results show that our approach outperformed the existing naive U-Net methods.
    Figure 1. The schematic illustration of the meta-learning-based zonal segmentation network combines a 2D U-Net and an adversarial network for determining the shape prior.
    Figure 2. Validation result of meta-learning based zonal segmentation model with the adversarial network, where (a) presents the T2w images, (b) shows the ground truth of zonal label, and (c) states the results of our approach. The CZ is masked in green, and PZ is in red.
  • A mutual communicated model based on multi-parametric MRI for automated prostate cancer segmentation and classification
    Piqiang Li1, Zhao Li2, Qinjia Bao2, Kewen Liu1, Xiangyu Wang3, Guangyao Wu4, and Chaoyang Liu2
    1School of Information Engineering, Wuhan University of Technology, Wuhan, China, 2State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathmatics, Innovation Academy for Precision Measurement Science and Technology, Wuhan, China, 3Department of Radiology, The First Affiliated Hospital of Shenzhen University, Shenzhen, China, 4Department of Radiology, Shenzhen University General Hospital, Shenzhen, China
    We proposed a Mutual Communicated Deep learning Segmentation and Classification Network (MC-DSCN) for prostate cancer based on multi-parametric MRI.
    The overall architecture of the proposed MC-DSCN network for prostate segmentation and classification. The coarse segmentation component (CSC) is constructed to generate coarse masks. The classification component extracts and fuses multi-parametric feature information and produce the lesion localization maps (CRM). The T2w images are concatenated with the CRM, then fed into the fine segmentation component (FSC) to generate the fine-mask.
    (a-d)The comparisons for different segmentation network, including Unet, Res-Unet, coarse segmentation network(CSC), fine segmentation network (FSC). The loss is indicated in brackets, including dice loss and the fusion loss(dice loss, the online rank loss). Both CSC and FSC are based on a residual U-net with an attention block. (e-f) the comparison of PCa Classification ROC curve based on different inputs. (e) the inputs include only T2w, T2w with coarse-mask, only ADC, ADC with coarse-mask. (f) the inputs include ADC with coarse-mask, multi-parametric images with coarse-mask.
  • A novel unsupervised domain adaptation method for deep learning-based prostate MR image segmentation
    Cheng Li1, Hui Sun1, Taohui Xiao1, Xin Liu1, Hairong Zheng1, and Shanshan Wang1
    1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
    Unsupervised domain adaptation is crucial for the applications of deep learning-based prostate MR image segmentation models. Our method designs an effective approach to generate highly accurate pseudo labels for unlabeled target domain training data and shows promising test results.
    Figure 1. The proposed framework. Source domain labeled training data are employed first to train a network that generates pseudo labels for the target domain unlabeled training data. Then, the combined source domain labeled training data and target domain pseudo-labeled training data are utilized to achieve our proposed cross-domain cross-network optimization.
    Figure 4. Example segmentation maps when transferring models from Domain 1 to Domain 2. From left to right, the three columns correspond to the transverse plane, the sagittal plane, and the coronal plane. From the head to bottom, the four rows refer to the ground-truth manual segmentation, the outputs of models trained directly on Domain 2 training set, the outputs of models trained on Domain 1 labeled training set, and the outputs of models trained on Domain 1 labeled training set and Domain 2 pseudo-labeled training set with the proposed cross-domain cross-network optimization method.
  • Automated image segmentation of prostate MR elastography by dense-like U-net.
    Nader Aldoj1, Federico Biavati1, Sebastian Stober2, Marc Dewey1, Patrick Asbach1, and Ingolf Sack1
    1Charité, Berlin, Germany, 2Ovgu Magdeburg, Magdeburg, Germany
    MR elastography maps can be used for prostate and zones segmentation due to the excellent segmentation results even when compared to the standard high-resolution T2w that is mostly used for anatomical segmentation. 
    Figure 1: Segmentation examples of individual models: first column (A) shows the original image, second (B), third (C) and forth column (D) show masks of prostate, central and peripheral zones, respectively. Rows from top to bottom represents mag, c, phi maps, T2w, DWI, and ADC respectively.
    Figure 2: Examples of segmentation results of the unified model: All segmented masks resulted from combining all mre maps as input, and the resulting masks were propagated to all other registered sequences. Columns A, B and C show masks of the prostate, CZ and PZ respectively. Top row is the mag images together with overlaid ground truth masks. The second row at the top to bottom show the predicted masks overlaid on mag, c, phi, T2w, DWI and ADC images respectively.
  • Machine learning challenge using uniform prostate MRI scans from 4 centers (PRORAD)
    Harri Merisaari1, Pekka Taimen2, Otto Ettala2, Juha Knaapila2, Kari T Syvänen2, Esa Kähkönen2, Aida Steiner2, Janne Verho2, Paula Vainio2, Marjo Seppänen3, Jarno Riikonen4, Sanna Mari Vimpeli4, Antti Rannikko5, Outi Oksanen5, Tuomas Mirtti5, Ileana Montoya Perez1, Tapio Pahikkala1, Parisa Movahedi1, Tarja Lamminen2, Jani Saunavaara2, Peter J Boström2, Hannu J Aronen1, and Ivan Jambor6
    1University of Turku, Turku, Finland, 2Turku University Hospital, Turku, Finland, 3Satakunta Central Hospital, Pori, Finland, 4Tampere University Hospital, Tampere, Finland, 5Helsinki University Hospital, Helsinki, Finland, 6Icahn School of Medicine at Mount Sinai, New York, NY, United States
    PRORAD is a series of machine learning challenges hosted at CodaLab which provide access to prostate MRI data sets from 4 centers performed using a publicly available IMPROD bpMRI acquisition protocol. 

    Figure 1 Phases of the machine learning challenge. 1) Data, Pre-processing and Feature extraction has been done. 2) Participant need to pre-process feature data with method of choice, including imputation of missing data, build a classifier with selected features, and validate the results with data from Site I. 3) External validation with unseen data from centers 1 and 2, with a limited number of evaluations. 4) The final test of the trained model and machine learning process with unseen data from centers 1 and 2, and completely unseen centers III and IV.
    Figure 2 Data management of the machine learning (ML) challenge. Radiomic feature values and ground truth values are both given for Training/Validation of ML model (A). Only radiomic feature values are given for Leaderboard evaluations (B), where results are given five times to allow minor edits to the ML, and in final evaluation (D), where only one submission is done (C). Leaderboard and Test set (B-D) ground truth labels are hidden inside the Codalab server where performance evaluations take place by running python code through Docker package.
  • Evaluation of the inter-reader reproducibility of the PI-QUAL scoring system for prostate MRI quality
    Francesco Giganti1, Eoin Dinneen1, Veeru Kasivisvanathan1, Aiman Haider2, Alex Freeman2, Mark Emberton1, Greg Shaw2, Caroline M Moore1, and Clare Allen2
    1University College London, London, United Kingdom, 2University College London Hospital, London, United Kingdom
    We found substantial agreement (κ = 0.77; percent agreement = 80%) between two expert radiologists when assessing prostate MRI quality for each single PI-QUAL score (1 to 5). The composition of the PI-QUAL will need to undergo further refinements.

    Fig. 1: Three cases of PI-QUAL score.

    From left to right for each row: axial T2-weighted, diffusion (b-values and ADC map) and dynamic-contrast enhanced imaging.

    PI-QUAL 2: only one sequence is of acceptable diagnostic quality (T2-WI). It is not possible to rule in and to rule out all significant lesions.

    PI-QUAL 3: two sequences taken together are of acceptable diagnostic quality. It is possible to rule in but not to rule out all significant lesions.

    PI-QUAL 4: at least two sequences are independently of diagnostic quality, and it is possible to rule in and rule out all significant lesions.

    Table 1: The PI-QUAL score.
  • Prostate Cancer Detection Using High b-Value Diffusion MRI with a Multi-task 3D Residual Convolutional Neural Network
    Guangyu Dan1,2, Min Li3, Mingshuai Wang4, Zheng Zhong1,2, Kaibao Sun1, Muge Karaman1,2, Tao Jiang3, and Xiaohong Joe Zhou1,2,5
    1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China, 4Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China, 5Departments of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States
    By using multi-task learning, 3D deep residual convolutional neural network yielded an excellent and stable prostate cancer detection performance in peripheral zone (AUC of 0.990±0.008) and transitional zone (AUC of 0.983±0.016) with high b-value diffusion MRI.
    Figure 2. 3D deep residual neural network architecture for prostate cancer detection in this study. (a) R3DPZ for prostate cancer detection in PZ. (b) R3DTZ for prostate cancer detection in TZ. (c) Multi-task R3D (R3DMT) for prostate cancer detection in both PZ and TZ. The input is a 32×32×11 spatial-b-value volume. Each “3D Conv” block consists of two 3D convolutional residual layers. The black arrows represent the shortcut connection.
    Figure 3. Mean AUC, sensitivity, and specificity as a function of epoch number for PZ cancer detection (a, b, and c) and TZ cancer detection (d, e, and f) on testing data. The blue curve represents multi-task R3D learning, R3DMT, the red curve represents R3D learning, R3DPZ, in the first row or R3DTZ in the second row.
  • T2-Weighted MRI-Derived Texture Features in Characterization of Prostate Cancer
    Dharmesh Singh1, Virendra Kumar2, Chandan J Das3, Anup Singh1, and Amit Mehndiratta1
    1Centre for Biomedical Engineering (CBME), Indian Institute of Technology (IIT) Delhi, New Delhi, India, 2Department of NMR, All India Institute of Medical Sciences (AIIMS) Delhi, New Delhi, India, 3Department of Radiology, All India Institute of Medical Sciences (AIIMS) Delhi, New Delhi, India
    Texture analysis based machine learning approaches are presented in characterization of PI-RADS v2 grades of prostate cancer using T2WI. The use of texture features extracted from T2WI, DWI and ADC improve the accuracy of prostate cancer characterization by almost 23% compared to T2WI alone
    Figure 1: ROC plot for a) LG vs. IG vs. HG and b) PI-RADS grade 4 vs. grade 5 classification using T2WI. Red curves stand for the performance of linear SVM, green curves for Gaussian SVM and blue curves for KNN classifier. ROC = Receiver-operating characteristics, CV = cross-validation, SVM = Support vector machine, KNN = K-nearest neighbour, DWI = Diffusion-weighted imaging, ADC = Apparent diffusion coefficient
    Table 1: Features extracted from different texture models. FOS = First order statistics, GLCM = Gray level co-occurrence matrix, GLRLM = Gray level run length matrix, SFM = Statistical feature matrix, LTEM = Law's texture energy measures
  • Classification of Cancer at Prostate MRI: Artificial Intelligence versus Clinical Assessment and Human-Machine Synergy
    guiqin LIU1, Guangyu Wu1, yongming Dai2, Ke Xue2, and Shu Liao3
    1Radiology, Renji Hospital,Shanghai Jiaotong University School of Medicine, Shanghai, China, 2United Imaing Healthcare, Shanghai, China, 3Shanghai United Imaging Intelligence Co. Ltd, Shanghai, China
    Based on multi-center cohorts, AI model could independently diagnose PCa with remarkable false negative and sensitivity. For the diagnosis performance, although AI performed suboptimal, the human-led synergy method performed equivalent to clinical assessment with improved consistency.
    The flowchart of the study. PCa: prostate cancer; BPH: benign prostatic hyperplasia.
    Artificial intelligence architecture. a. Small Vnet (sVnet), based on V-Net with modifications, composed of one input block, four downsampling blocks (Down Block), four upsampling blocks (Up Block), four merge blocks (Merge Block) and one output block. The horizontal arrow denotes the transfer of residual information from the early stage to the later stage. b. Multi-small Vnet (msVnet), where two sVnets are cascaded.
  • Repeatability of Radiomic Features in T2-Weighted Prostate MRI: Impact of Pre-processing Configurations
    Dyah Ekashanti Octorina Dewi1, Mohammed R. S. Sunoqrot1, Gabriel Addio Nketiah1, Elise Sandsmark2, Sverre Langørgen2, Helena Bertilsson3,4, Mattijs Elschot1,2, and Tone Frost Bathen1,2
    1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, 2Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 3Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway, 4Department of Urology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
    Repeatability of T2W-MRI radiomic features is important to develop consistent imaging biomarkers and evaluate prostate cancer. This study visualizes that repeatability of radiomic features varies based on anatomical zones and lesions, pre-processing, and feature itself.
    Heatmaps of ICCs in (a) WP and (b) L datasets with selected good features (ICC ≥ 0.75) explain the patterns of repeatability in different prostate regions and lesions relative to pre-processing configurations and radiomic features.
    The highest repeatability results on each prostate regions and lesions based on radiomic feature groups based on the and pre-processing configurations.
  • Rapid submillimeter high-resolution prostate T2 mapping with a deep learning constrained Compressed SENSE reconstruction
    Masami Yoneyama1, Takashige Yoshida2, Jihun Kwon1, Kohei Yuda2, Yuki Furukawa2, Nobuo Kawauchi2, Johannes M Peeters3, and Marc Van Cauteren3
    1Philips Japan, Tokyo, Japan, 2Radiology, Tokyo Metropolitan Police Hospital, Tokyo, Japan, 3Philips Healthcare, Best, Netherlands
    Compressed SENSE-AI clearly reduces noise artifacts and significantly improves the accuracy and robustness of T2 values in submillimeter high-resolution prostate ME-TSE T2mapping compared with conventional SENSE and C-SENSE techniques.
    Figure 1. Representative T2 maps of ME-TSE T2 mapping with SENSE, C-SENSE and CS-AI. CS-AI significantly cleaned up the image noise.
    Figure 3. Comparison of high-resolution T2 weighted image with CS-AI and proposed 0.7mm high-resolution ME-TSE T2 map with CS-AI.
  • Sensitivity of radiomics to inter-reader variations in prostate cancer delineation on MRI should be considered to improve generalizability
    Rakesh Shiradkar1, Michael Sobota1, Leonardo Kayat Bittencourt2, Sreeharsha Tirumani2, Justin Ream3, Ryan Ward3, Amogh Hiremath1, Ansh Roge1, Amr Mahran1, Andrei Purysko3, Lee Ponsky2, and Anant Madabhushi1
    1Case Western Reserve University, Cleveland, OH, United States, 2University Hospitals Cleveland Medical Center, Cleveland, OH, United States, 3Cleveland Clinic, Cleveland, OH, United States
    Inter-reader variation in delineating prostate cancer on MRI affects radiomic features in their ability to identify clinically significant prostate cancer. A more conservative approach in delineations may ensure better generalizability of predictive models trained using radiomics.
    Figure 1: Prostate cancer delineations of three radiologists (R1(red), R2(yellow) and R3(green)) on T2W and ADC. For smaller lesions (patient 1), all 3 readers had a good overlap. For larger (patient 2) and multi-focal lesions (patient 3), there was considerable variation in delineations that affect radiomics and robustness of classifiers.
    Table 3: Individual and inter-reader performance assessment
  • Radiomics models based on ADC maps for predicting high-grade prostate cancer at radical prostatectomy: comparison with preoperative biopsy
    Chao Han1, Shuai Ma1, Xiang Liu1, Yi Liu1, Changxin Li2, Yaofeng Zhang2, Xiaodong Zhang1, and Xiaoying Wang1
    1Department of Radiology, Peking University First Hospital, Beijing, China, 2Beijing Smart Tree Medical Technology Co. Ltd., Beijing, China
    Four radiomics models based on manual/automatic segmentation of prostate gland/prostate cancer (PCa) lesion from ADC maps were developed and tested to distinguish high-grade and low-grade PCa, which obtained roughly the same diagnostic efficacy as preoperative biopsy.
    Figure 3. ROC curves of the 4 radiomics models and TRUS biopsy in the training cohort (a) and test cohort (b). (Model 1 is based on manual segmentation of the prostate gland. Model 2 is based on manual segmentation of prostate cancer lesions. Model 3 is based on automatic segmentation of the prostate gland by the 3D prostate segmentation algorithm. Model 4 is based on thresholding segmentation of prostate cancer lesions by a fast-automatic thresholding algorithm. ROC: receiver operating characteristic; TRUS: transrectal ultrasound.)
    Figure 5. Decision curve analysis comparing the net benefits of different radiomics models and TURS biopsy for the test cohort. (Model 1 is based on manual segmentation of the prostate gland. Model 2 is based on manual segmentation of prostate cancer lesions. Model 3 is based on automatic segmentation of the prostate gland by the 3D prostate segmentation algorithm. Model 4 is based on thresholding segmentation of prostate cancer lesions by a fast-automatic thresholding algorithm. TRUS: transrectal ultrasound.)
  • Non-invasive Gleason Score Classification with VERDICT-MRI
    Vanya V Valindria1, Saurabh Singh2, Eleni Chiou1, Thomy Mertzanidou1, Baris Kanber1, Shonit Punwani2, Marco Palombo1, and Eleftheria Panagiotaki1
    1Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom, 2Centre for Medical Imaging, University College London, London, United Kingdom
    We present non-invasive Gleason Score (GS) classification using VERDICT-MRI with convolutional neural networks. Results show that the combination of VERDICT maps achieves the best GS classification performance and outperforms reported multi-parametric MRI GS classification. 
    Figure 1. Flowchart of Gleason score classification. We classify the predefined lesion ROIs on the VERDICT maps using DenseNet and SE-ResNet. The network then gives the corresponding Gleason score to the lesion.
    Figure 2. Results of five-point GS classification using two different networks: DenseNet and SE-ResNet on VERDICT. SE-ResNet with VERDICT generally yields better performance than DenseNet. VERDICT gives higher classification metrics compared to those reported in GS classification with bi-and multi-parametric MRI.
  • Prostate Cancer Risk Maps Derived from Multi-parametric MRI and Validated by Histopathology
    Matthew Gibbons1, Jeffry P Simko2,3, Peter R Carroll2, and Susan Noworolski1
    1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Urology, University of California, San Francisco, San Francisco, CA, United States, 3Pathology, University of California, San Francisco, San Francisco, CA, United States
    Multi-parametric MRI (mpMRI) is a clinically useful tool to assess prostate cancer. This study showed the feasibility of MRI generated cancer risk maps to detect cancer lesions >0.1cc and quantify the volume of cancer. The maps were validated by histopathology after prostatectomy.
    Fig 1: Information from a) histopathology, mpMRI images b) T2W, c) ADC, d) FA, and e) DCE) was combined in a logistic regression model to generate the f) cancer risk .aps in the TZ and the PZ. In this example, a combination in an ROI of hypointense T2W and ADC, hyperintense DCE resulted in a high-risk region in the cancer maps.
    Fig. 2: Prostate cancer volume comparison of MRI cancer map vs histopathology. Cases with overestimated (underestimated) cancer volume are above (below) the solid blue one-to-one line. Dashed bounding lines were defined to indicate outliers (1cc ± 1.2·volume_pathology). 80% of cases were within the boundaries.
  • Deep learning reconstruction enables highly accelerated T2 weighted prostate MRI
    Patricia M Johnson1, Angela Tong1, Paul Smereka1, Awani Donthireddy1, Robert Petrocelli1, Hersh Chandarana1, and Florian Knoll1
    1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New york, NY, United States

    Diagnostic quality highly accelerated axial and coronal T2-weighted prostate images were reconstructed using deep learning methods with ≤1 minute of acquisition time, which can enable rapid screening prostate MRI. 

    Figure 4. Coronal image results for subject 1 (top row) and subject 2 (bottom row). Soft-sense reconstructions are shown in a) and d). VN reconstructions are shown in b) and e) while the fully sampled, ground-truth images are shown in c) and f). The value indicated on the images is the calculated SSIM of the slice shown.
    Figure 1. Data processing pipeline, and structure of the reconstruction network. First, a zero-filled reconstruction is generated from the under-sampled k space and two sets of coil sensitivity maps. Two sets of sensitivity estimates are required because the anatomy extends beyond the field of view, as described in Uecker et al.6 Then, this reconstruction, along with the raw k-space data and sensitivity maps are passed as the input to the reconstruction network. The reconstruction network has 10 stages (t =10), each stage applies data consistency and regularization.
  • Reduction of B1-field induced inhomogeneity for body imaging at 7T using deep learning and synthetic training data.
    Seb Harrevelt1, Lieke Wildenberg2, Dennis Klomp2, C.A.T. van den Berg2, Josien Pluim3, and Alexander Raaijmakers1
    1TU Eindhoven, Utrecht, Netherlands, 2UMC Utrecht, Utrecht, Netherlands, 3TU Eindhoven, Rossum, Netherlands
    We find that a deep learning approach to bias field suppression in 7T images can achieve good results, even when trained on artificially created 7T data that is based on 1.5T data.
    Applying the pix2pix model to real measured 7T MRI data over different anatomies (left) and its corresponding output (right). Note that instead of showing the model input (8 single-channel images), the figure shows the sum of magnitude of these input images.
    Graphical representation of data creation pipeline. Going from left to right, we start with a set of simulated B1+ and B1- fields, and a target prostate image. The B1+ and B1- fields are being registered to the shape of the prostate data whereafter the registered B1+ data is shimmed and scaled to mimic the signal of a T2w acquisition. Now combining the scaled B1+, B1- and prostate image results in the 8-channel input data for our model.
  • Deep learning for synthesizing apparent diffusion coefficient maps of the prostate: A tentative study based on generative adversarial networks
    lei hu1, Jungong Zhao1, Caixia Fu2, and Thomas Benkert3
    1Department of Diagnostic and Interventional Radiology, Shanghai Jiao Tong University Affiliated Sixt, 上海, China, 2MR Application Development, Siemens Shenzhen magnetic Resonance Ltd, shenzhen, China, 3MR Application Predevelopment, Siemens Healthcare, Erlangen, Gernmany, Erlangen, Germany
    The proposed deep learning algorithm might be a feasible method to generate ADC maps instead of z-ADC maps without significant hardware dependance and additional scan time.
    Fig.1 The overview of our framework.
    Fig.2 A 61-year-old man with prostatic cancer with prostate specific antigen level of 50.88 ng/ml. Both of s-ADCb1000 and s-ADCb1500 had good performance in displaying the prostate, pelvic floor musclesm and pubic symphysis while s-ADCb50 produced blurry images of these structures. Regarding level of detail, s-ADCb1000 is more similar to z-ADC than s-ADCb1500 and maintains the details seen in z-ADC (red arrows).