1
|
Lubner MG, Ziemlewicz TJ, Wells SA, Li K, Wu PH, Hinshaw JL, Lee FT, Brace CL. Advanced CT techniques for hepatic microwave ablation zone monitoring and follow-up. Abdom Radiol (NY) 2022; 47:2658-2668. [PMID: 34731282 DOI: 10.1007/s00261-021-03333-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 01/18/2023]
Abstract
PURPOSE To evaluate utility of advanced CT techniques including HighlY constrained back-projection and dual-energy CT for intra- and post-procedure hepatic microwave ablation zone monitoring. METHODS 8 hepatic microwave ablations were performed in 4 adult swine (5 min/65 W). Low-dose routine CECT and dual-energy CT images were obtained every 1 min during ablation. Images were reconstructed ± HYPR. Image quality and dose metrics were collected. 21 MWA were performed in 4 adult swine. Immediate post-procedure CECT was performed in the arterial, portal venous, and delayed phases using both routine and DECT imaging with full-dose weight-based IV contrast dosing. An additional 16 MWA were subsequently performed in 2 adult swine. Immediate post-procedure CT was performed with half-dose IV contrast using routine and DECT. 12 patients (10 M/2F, mean age 62.4 yrs) with 14 hepatic tumors (4 HCC, 10 metastatic lesions) treated with MWA were prospectively imaged with DECT 1 month post-procedure. 120 kV equivalent images were compared to DECT [51 keV, iodine material density]. Image quality and dose metrics were collected. RESULTS Gas created during MWA led to high CNR in all intraprocedural CT datasets. Optimal CNRs were noted at 4 min with CNR 6.7, 15.5,15.9, and 21.5 on LD-CECT, LD-CECT + HYPR, DECT, and DECT + HYPR, respectively (p < 0.001). Image quality scores at 4 min were 1.8, 2.8, 2.4, and 3, respectively (p < 0.001). Mean radiation dose (CTDIvol) was eightfold higher for the DECT series. For swine, post-procedural DECT images (IMD/51 keV) showed improved CNR compared to routine CT at all time points with full and with reduced dose contrast (CNR 4.6, 3.2, and 1.5, respectively, at half-contrast dose, p < 0.001). For human subjects, the 51 keV and IMD images showed higher CNRs (5.8, 4.8 vs 4.0, p < 0.001) and SNRs (3.7, 5.9 vs 2.8). Ablation zone sharpness was improved with DECT (routine 3.0 ± 0.7, DECT 3.5 ± 0.5). Diagnostic confidence was higher with DECT (routine 2.3 ± 0.9, DECT 2.6 ± 0.8). Mean DLP for DECT was 905.7 ± 606 mGy-cm, CTDIvol 37.5 ± 21.2 mGy, and effective dose 13.6 ± 9.1 mSv, slightly higher than conventional CT series. CONCLUSION Advanced CT techniques can improve CT image quality in peri-procedural hepatic microwave ablation zone evaluation.
Collapse
Affiliation(s)
- Meghan G Lubner
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA.
| | - Timothy J Ziemlewicz
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
| | - Shane A Wells
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
| | - Ke Li
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Po-Hung Wu
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
- Department of Biomedical and Electrical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Electrical and Computer Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - J Louis Hinshaw
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
| | - Fred T Lee
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
| | - Chris L Brace
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Sciences Center, 600 Highland Ave, Madison, WI, 53792, USA
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Biomedical and Electrical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| |
Collapse
|
2
|
Subregion Radiomics Analysis to Display Necrosis After Hepatic Microwave Ablation-A Proof of Concept Study. Invest Radiol 2021; 55:422-429. [PMID: 32028297 DOI: 10.1097/rli.0000000000000653] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES The aim of this study was to improve the visualization of coagulation necrosis after computed tomography (CT)-guided microwave ablation (MWA) in routine postablational imaging. MATERIALS AND METHODS Ten MWAs were performed in 8 pigs under CT guidance. After each ablation, we obtained contrast-enhanced CT scans in venous phase. Ablations were then resected as a whole, and histologic slices were obtained orthogonally through the ablation center. Subsequently, a vital stain was applied to the sections for visualization of coagulation necrosis. Computed tomography images were reformatted to match the histologic slices. Afterwards, quantitative imaging features were extracted from the subregions of all images, and binary classifiers were used to predict the presence of coagulation necrosis for each subregion. From this, heatmaps could be created, which visually represented the extent of necrosis in each CT image. Two independent observers evaluated the extent of coagulative necrosis between the heat maps and histological sections. RESULTS We applied 4 different classifiers, including a generalized linear mixed model (GLMM), a stochastic gradient boosting classifier, a random forest classifier, and a k-nearest neighbor classifier, out of which the GLMM showed the best performance to display coagulation necrosis. The GLMM resulted in an area under the curve of 0.84 and a Jaccard index of 0.6 between the generated heat map and the histologic reference standard as well as a good interobserver agreement with a Jaccard index of 0.9. CONCLUSIONS Subregion radiomics analysis may improve visualization of coagulation necrosis after hepatic MWA in an in vivo porcine model.
Collapse
|
3
|
Wu PH, Bedoya M, White J, Brace CL. Feature-based automated segmentation of ablation zones by fuzzy c-mean clustering during low-dose computed tomography. Med Phys 2021; 48:703-714. [PMID: 33237594 PMCID: PMC8594246 DOI: 10.1002/mp.14623] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/21/2020] [Accepted: 08/10/2020] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Intra-procedural monitoring and post-procedural follow-up is necessary for a successful ablation treatment. An imaging technique which can assess the ablation geometry accurately is beneficial to monitor and evaluate treatment. In this study, we developed an automated ablation segmentation technique for serial low-dose, noisy ablation computed tomography (CT) or contrast-enhanced CT (CECT). METHODS Low-dose, noisy temporal CT and CECT volumes were acquired during microwave ablation on normal porcine liver (four with non-contrast CT and eight with CECT). Highly constrained backprojection (HYPR) processing was used to recover ablation zone information compromised by low-dose noise. First-order statistic features and normalized fractional Brownian features (NBF) were used to segment ablation zones by fuzzy c-mean clustering. After clustering, the segmented ablation zone was refined by cyclic morphological processing. Automatic and manual segmentations were compared to gross pathology with Dice's coefficient (morphological similarity), while cross-sectional dimensions were compared by percent difference. RESULTS Automatic and manual segmentations of the ablation zone were very similar to gross pathology (Dice Coefficients: Auto.-Path. = 0.84 ± 0.02; Manu.-Path. = 0.76 ± 0.03, P = 0.11). The differences in ablation area, major diameter and minor diameter were 17.9 ± 3.2%, 11.1 ± 3.2% and 16.2 ± 3.4%, respectively, when comparing automatic segmentation to gross pathology, which were lower than the differences of 32.9 ± 16.8%, 13.0 ± 9.8% and 21.8 ± 5.8% when comparing manual segmentation to gross pathology. Manual segmentations tended to overestimate gross pathology when ablation area was less than 15 cm2 , but the automated segmentation tended to underestimate gross pathology when ablation zone is larger than 20 cm2 . CONCLUSION Fuzzy c-means clustering may be used to aid automatic segmentation of ablation zones without prior information or user input, making serial CT/CECT has more potential to assess treatments intra-procedurally.
Collapse
Affiliation(s)
- Po-hung Wu
- Department of Electrical and Computer Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| | - Mariajose Bedoya
- Department of Medical Physics, University of Wisconsin - Madison, 1111 Highland Ave, Rm 1005, Madison, WI 53705, USA
| | - Jim White
- Department of Biomedical Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| | - Christopher L. Brace
- Department of Biomedical Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA
- Department of Radiology, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI 53705, USA
| |
Collapse
|
4
|
Bressem KK, Vahldiek JL, Erxleben C, Geyer B, Poch F, Shnayien S, Lehmann KS, Hamm B, Niehues SM. Comparison of different 4D CT-Perfusion algorithms to visualize lesions after microwave ablation in an in vivo porcine model. Int J Hyperthermia 2019; 36:1098-1107. [DOI: 10.1080/02656736.2019.1679894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Affiliation(s)
- Keno K. Bressem
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Janis L. Vahldiek
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Christoph Erxleben
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Beatrice Geyer
- Department of Surgery, Charité-University Medicine Berlin, Berlin, Germany
| | - Franz Poch
- Department of Surgery, Charité-University Medicine Berlin, Berlin, Germany
| | - Seyd Shnayien
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Kai S. Lehmann
- Department of Surgery, Charité-University Medicine Berlin, Berlin, Germany
| | - B. Hamm
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Stefan M. Niehues
- Department of Radiology, Charité-University Medicine Berlin, Berlin, Germany
| |
Collapse
|
5
|
Pohlman RM, Turney MR, Wu P, Brace CL, Ziemlewicz TJ, Varghese T. Two-dimensional ultrasound-computed tomography image registration for monitoring percutaneous hepatic intervention. Med Phys 2019; 46:2600-2609. [PMID: 31009079 PMCID: PMC6758542 DOI: 10.1002/mp.13554] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 04/14/2019] [Accepted: 04/15/2019] [Indexed: 01/03/2023] Open
Abstract
PURPOSE Deformable registration of ultrasound (US) and contrast enhanced computed tomography (CECT) images are essential for quantitative comparison of ablation boundaries and dimensions determined using these modalities. This comparison is essential as stiffness-based imaging using US has become popular and offers a nonionizing and cost-effective imaging modality for monitoring minimally invasive microwave ablation procedures. A sensible manual registration method is presented that performs the required CT-US image registration. METHODS The two-dimensional (2D) virtual CT image plane that corresponds to the clinical US B-mode was obtained by "virtually slicing" the 3D CT volume along the plane containing non-anatomical landmarks, namely points along the microwave ablation antenna. The initial slice plane was generated using the vector acquired by rotating the normal vector of the transverse (i.e., xz) plane along the angle subtended by the antenna. This plane was then further rotated along the ablation antenna and shifted along with the direction of normal vector to obtain similar anatomical structures, such as the liver surface and vasculature that is visualized on both the CT virtual slice and US B-mode images on 20 patients. Finally, an affine transformation was estimated using anatomic and non-anatomic landmarks to account for distortion between the colocated CT virtual slice and US B-mode image resulting in a final registered CT virtual slice. Registration accuracy was measured by estimating the Euclidean distance between corresponding registered points on CT and US B-mode images. RESULTS Mean and SD of the affine transformed registration error was 1.85 ± 2.14 (mm), computed from 20 coregistered data sets. CONCLUSIONS Our results demonstrate the ability to obtain 2D virtual CT slices that are registered to clinical US B-mode images. The use of both anatomical and non-anatomical landmarks result in accurate registration useful for validating ablative margins and comparison to electrode displacement elastography based images.
Collapse
Affiliation(s)
- Robert M. Pohlman
- Department of Medical PhysicsUniversity of Wisconsin School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | - Michael R. Turney
- Department of Medical PhysicsUniversity of Wisconsin School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | - Po‐Hung Wu
- Department of RadiologyUniversity of Wisconsin School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | - Christopher L. Brace
- Department of RadiologyUniversity of Wisconsin School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | - Timothy J. Ziemlewicz
- Department of RadiologyUniversity of Wisconsin School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWI53706USA
| | - Tomy Varghese
- Department of Medical PhysicsUniversity of Wisconsin School of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWI53706USA
| |
Collapse
|