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Aldoj N, Biavati F, Dewey M, Hennemuth A, Asbach P, Sack I. Fully automated quantification of in vivo viscoelasticity of prostate zones using magnetic resonance elastography with Dense U-net segmentation. Sci Rep 2022; 12:2001. [PMID: 35132102 PMCID: PMC8821548 DOI: 10.1038/s41598-022-05878-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 01/05/2022] [Indexed: 11/13/2022] Open
Abstract
Magnetic resonance elastography (MRE) for measuring viscoelasticity heavily depends on proper tissue segmentation, especially in heterogeneous organs such as the prostate. Using trained network-based image segmentation, we investigated if MRE data suffice to extract anatomical and viscoelastic information for automatic tabulation of zonal mechanical properties of the prostate. Overall, 40 patients with benign prostatic hyperplasia (BPH) or prostate cancer (PCa) were examined with three magnetic resonance imaging (MRI) sequences: T2-weighted MRI (T2w), diffusion-weighted imaging (DWI), and MRE-based tomoelastography, yielding six independent sets of imaging data per patient (T2w, DWI, apparent diffusion coefficient, MRE magnitude, shear wave speed, and loss angle maps). Combinations of these data were used to train Dense U-nets with manually segmented masks of the entire prostate gland (PG), central zone (CZ), and peripheral zone (PZ) in 30 patients and to validate them in 10 patients. Dice score (DS), sensitivity, specificity, and Hausdorff distance were determined. We found that segmentation based on MRE magnitude maps alone (DS, PG: 0.93 ± 0.04, CZ: 0.95 ± 0.03, PZ: 0.77 ± 0.05) was more accurate than magnitude maps combined with T2w and DWI_b (DS, PG: 0.91 ± 0.04, CZ: 0.91 ± 0.06, PZ: 0.63 ± 0.16) or T2w alone (DS, PG: 0.92 ± 0.03, CZ: 0.91 ± 0.04, PZ: 0.65 ± 0.08). Automatically tabulated MRE values were not different from ground-truth values (P>0.05). In conclusion, MRE combined with Dense U-net segmentation allows tabulation of quantitative imaging markers without manual analysis and independent of other MRI sequences and can thus contribute to PCa detection and classification.
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Affiliation(s)
- Nader Aldoj
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Federico Biavati
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Marc Dewey
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,DKTK (German Cancer Consortium), Partner Site Berlin, Berlin, Germany.,Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Berlin, Germany
| | - Anja Hennemuth
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Patrick Asbach
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Reiter R, Majumdar S, Kearney S, Kajdacsy-Balla A, Macias V, Crivellaro S, Abern M, Royston TJ, Klatt D. Investigating the heterogeneity of viscoelastic properties in prostate cancer using MR elastography at 9.4T in fresh prostatectomy specimens. Magn Reson Imaging 2022; 87:113-118. [PMID: 35007693 DOI: 10.1016/j.mri.2022.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/29/2021] [Accepted: 01/04/2022] [Indexed: 11/20/2022]
Abstract
PURPOSE To quantify the heterogeneity of viscoelastic tissue properties in prostatectomy specimens from men with prostate cancer (PC) using MR elastography (MRE) with histopathology as reference. METHODS Twelve fresh prostatectomy specimens were examined in a preclinical 9.4T MRI scanner. Maps of the complex shear modulus (|G*| in kPa) with its real and imaginary part (G' and G" in kPa) were calculated at 500 Hz. Prostates were divided into 12 segments for segment-wise measurement of viscoelastic properties and histopathology. Coefficients of variation (CVs in %) were calculated for quantification of heterogeneity. RESULTS Group-averaged values of cancerous vs. benign segments were significantly increased: |G*| of 12.13 kPa vs. 6.14 kPa, G' of 10.84 kPa vs. 5.44 kPa and G" of 5.45 kPa vs. 2.92 kPa, all p < 0.001. In contrast, CVs were significantly increased for benign segments: 23.59% vs. 26.32% (p = 0.014) for |G*|, 27.05% vs. 37.84% (p < 0.003) for G', and 36.51% vs. 50.37% (p = 0.008) for G". DISCUSSION PC is characterized by a stiff yet homogeneous biomechanical signature, which may be due to the unique nondestructive growth pattern of PC with intervening stroma, providing a rigid scaffold in the affected area. In turn, increased heterogeneity in benign prostate segments may be attributable to the presence of different prostate zones with involvement by specific nonmalignant pathology.
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Affiliation(s)
- Rolf Reiter
- Department of Radiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Hindenburgdamm 30, 12203 Berlin, Germany; Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2, 10178 Berlin, Germany; Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Shreyan Majumdar
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Steven Kearney
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States
| | - André Kajdacsy-Balla
- Department of Pathology, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Virgilia Macias
- Department of Pathology, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Simone Crivellaro
- Department of Urology, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Michael Abern
- Department of Urology, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Thomas J Royston
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
| | - Dieter Klatt
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, 830 South Wood Street, Chicago, IL 60612, United States.
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In Vivo Quantification of Water Diffusion, Stiffness, and Tissue Fluidity in Benign Prostatic Hyperplasia and Prostate Cancer. Invest Radiol 2020; 55:524-530. [DOI: 10.1097/rli.0000000000000685] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Reiter R, Majumdar S, Kearney S, Kajdacsy‐Balla A, Macias V, Crivellaro S, Caldwell B, Abern M, Royston TJ, Klatt D. Prostate cancer assessment using MR elastography of fresh prostatectomy specimens at 9.4 T. Magn Reson Med 2019; 84:396-404. [DOI: 10.1002/mrm.28127] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Rolf Reiter
- Richard and Loan Hill Department of Bioengineering University of Illinois at Chicago Chicago Illinois
- Department of Radiology Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of Health Berlin Germany
| | - Shreyan Majumdar
- Richard and Loan Hill Department of Bioengineering University of Illinois at Chicago Chicago Illinois
| | - Steven Kearney
- Richard and Loan Hill Department of Bioengineering University of Illinois at Chicago Chicago Illinois
| | | | - Virgilia Macias
- Department of Pathology University of Illinois at Chicago Chicago Illinois
| | - Simone Crivellaro
- Department of Urology University of Illinois at Chicago Chicago Illinois
| | - Brandon Caldwell
- Department of Urology University of Illinois at Chicago Chicago Illinois
| | - Michael Abern
- Department of Urology University of Illinois at Chicago Chicago Illinois
| | - Thomas J. Royston
- Richard and Loan Hill Department of Bioengineering University of Illinois at Chicago Chicago Illinois
| | - Dieter Klatt
- Richard and Loan Hill Department of Bioengineering University of Illinois at Chicago Chicago Illinois
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Olsson LE, Johansson M, Zackrisson B, Blomqvist LK. Basic concepts and applications of functional magnetic resonance imaging for radiotherapy of prostate cancer. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2019; 9:50-57. [PMID: 33458425 PMCID: PMC7807726 DOI: 10.1016/j.phro.2019.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/27/2018] [Accepted: 02/08/2019] [Indexed: 12/30/2022]
Abstract
Recently, the interest to integrate magnetic resonance imaging (MRI) in radiotherapy for prostate cancer has increased considerably. MRI can contribute in all steps of the radiotherapy workflow from diagnosis, staging, and target definition to treatment follow-up. Of particular interest is the ability of MRI to provide a wide range of functional measures. The complexity of MRI as an imaging modality combined with the growing interest of the application to prostate cancer radiotherapy, emphasize the need for dedicated education within the radiation oncology community. In this context, an overview of the most common as well as a few upcoming functional MR imaging techniques is presented: the basic methodology and measurement is described, the link between the functional measures and the underlying biology is established, and finally relevant applications of functional MRI useful for prostate cancer radiotherapy are given.
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Affiliation(s)
- Lars E Olsson
- Department of Medical Radiation Physics, Translational Medicine, Lund University, Sweden.,Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
| | | | | | - Lennart K Blomqvist
- Department of Radiology, Molecular Medicine and Surgery, Karolinska University, Sweden
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New and Emerging Applications of Magnetic Resonance Elastography of Other Abdominal Organs. Top Magn Reson Imaging 2019; 27:335-352. [PMID: 30289829 DOI: 10.1097/rmr.0000000000000182] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increasing clinical experience and ongoing research in the field of magnetic resonance elastography (MRE) is leading to exploration of its applications in other abdominal organs. In this review, the current research progress of MRE in prostate, uterus, pancreas, spleen, and kidney will be discussed. The article will describe patient preparation, modified technical approach including development of passive drivers, modification of sequences, and inversion. The potential clinical application of MRE in the evaluation of several disease processes affecting these organs will be discussed. In an era of increasing adoption of multiparametric magnetic resonance imaging approaches for solving complex abdominal problems, abdominal MRE as a biomarker may be seamlessly incorporated into a standard magnetic resonance imaging examination to provide a rapid, reliable, and comprehensive imaging evaluation at a single patient appointment in the future.
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De Roover R, Crijns W, Poels K, Peeters R, Draulans C, Haustermans K, Depuydt T. Characterization of a novel liquid fiducial marker for multimodal image guidance in stereotactic body radiotherapy of prostate cancer. Med Phys 2018. [PMID: 29537613 DOI: 10.1002/mp.12860] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Liquid fiducial markers have shown to be a promising alternative to solid gold markers in terms of imaging artifact reduction, patient comfort, and compatibility with different imaging modalities. This study aims to investigate the performance of the novel BioXmark® liquid marker for state-of-the-art multimodal imaging used in prostate cancer (PCa) radiotherapy, encompassing kV CT/CBCT, multiparametric MRI, and kV x-ray imaging. In addition, automatic detection of the liquid markers in x-ray imaging for prostate motion monitoring during treatment was investigated. METHODS A total of eight BioXmark® liquid markers with varying volumes (range 5-300 μL) were casted on a square grid into a gelatin phantom insert. A cylindrical gold marker (QLRAD, length = 7 mm, Ø = 1 mm) was inserted for reference. Liquid marker visibility and streaking artifacts in CT/CBCT imaging were evaluated by placing the gelatin phantom into a CIRS anthropomorphic phantom. Relevant MRI characteristics such as the T2 and T1 relaxation times, the ADC value, and the relative proton density (ρH) were quantified by placing the gelatin phantom insert next to a T1MES mapping phantom and a water-filled syringe for reference. Ex vivo multiparametric MRI images were acquired by placing the gelatin phantom next to a resected prostate specimen. Anterior-posterior x-ray projection images were obtained by placing the gelatin phantom insert on top of an anthropomorphic pelvic phantom with internal pelvic bony structures and were acquired for five positions relative to the bony anatomy and 24 clinically relevant x-ray exposure settings. To quantify individual automatic marker detection, single markers were artificially isolated in the x-ray images using postprocessing. RESULTS Markers of all sizes were clearly visible on CT and CBCT images with only the largest marker volumes (100-300 μL) displaying artifacts similar in size to the gold fiducial marker. Artifact size increased with increasing liquid marker volume. Liquid markers displayed good contrast in ex vivo T1-weighted and ρH-weighted images. The markers were not visible in the ex vivo T2-weighted image. The liquid markers induced a chemical shift artifact in the obtained ADC-map. Automated detection in x-ray imaging was feasible with high detection success (four of five positions) for marker volumes in the range of 25-200 μL. None of the liquid markers were detected successfully when superimposed on a bony edge, independent of their size. CONCLUSIONS This study is the first to show the compatibility of BioXmark® liquid markers with multimodal image-guided radiotherapy for PCa. Compared to a solid gold marker, they had favorable results in both visibility and induced imaging artifacts. Liquid marker visibility in MRI imaging of the prostate does not solely depend on the low ρH value (not visible on T2-weighted image) but is also influenced by its relaxation times. Automated marker detection in x-ray images was feasible but better adapted marker detection algorithms are necessary for marker localization in the presence of bony edges. Hence, the liquid marker provides a minimally invasive (fine needles) and highly applicable alternative to current solid gold markers for multimodal image-guided prostate radiotherapy treatments.
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Affiliation(s)
- Robin De Roover
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven - University of Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Wouter Crijns
- Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Kenneth Poels
- Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Ronald Peeters
- Department of Radiology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Cédric Draulans
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven - University of Leuven, Herestraat 49, Leuven, B-3000, Belgium.,Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Karin Haustermans
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven - University of Leuven, Herestraat 49, Leuven, B-3000, Belgium.,Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
| | - Tom Depuydt
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven - University of Leuven, Herestraat 49, Leuven, B-3000, Belgium.,Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, Leuven, B-3000, Belgium
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