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Hamabuchi N, Ohno Y, Kimata H, Ito Y, Fujii K, Akino N, Takenaka D, Yoshikawa T, Oshima Y, Matsuyama T, Nagata H, Ueda T, Ikeda H, Ozawa Y, Toyama H. Effectiveness of deep learning reconstruction on standard to ultra-low-dose high-definition chest CT images. Jpn J Radiol 2023; 41:1373-1388. [PMID: 37498483 PMCID: PMC10687108 DOI: 10.1007/s11604-023-01470-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 07/09/2023] [Indexed: 07/28/2023]
Abstract
PURPOSE Deep learning reconstruction (DLR) has been introduced by major vendors, tested for CT examinations of a variety of organs, and compared with other reconstruction methods. The purpose of this study was to compare the capabilities of DLR for image quality improvement and lung texture evaluation with those of hybrid-type iterative reconstruction (IR) for standard-, reduced- and ultra-low-dose CTs (SDCT, RDCT and ULDCT) obtained with high-definition CT (HDCT) and reconstructed at 0.25-mm, 0.5-mm and 1-mm section thicknesses with 512 × 512 or 1024 × 1024 matrixes for patients with various pulmonary diseases. MATERIALS AND METHODS Forty age-, gender- and body mass index-matched patients with various pulmonary diseases underwent SDCT (CT dose index volume : mean ± standard deviation, 9.0 ± 1.8 mGy), RDCT (CTDIvol: 1.7 ± 0.2 mGy) and ULDCT (CTDIvol: 0.8 ± 0.1 mGy) at a HDCT. All CT data set were then reconstructed with 512 × 512 or 1024 × 1024 matrixes by means of hybrid-type IR and DLR. SNR of lung parenchyma and probabilities of all lung textures were assessed for each CT data set. SNR and detection performance of each lung texture reconstructed with DLR and hybrid-type IR were then compared by means of paired t tests and ROC analyses for all CT data at each section thickness. RESULTS Data for each radiation dose showed DLR attained significantly higher SNR than hybrid-type IR for each of the CT data (p < 0.0001). On assessments of all findings except consolidation and nodules or masses, areas under the curve (AUCs) for ULDCT with hybrid-type IR for each section thickness (0.91 ≤ AUC ≤ 0.97) were significantly smaller than those with DLR (0.97 ≤ AUC ≤ 1, p < 0.05) and the standard protocol (0.98 ≤ AUC ≤ 1, p < 0.05). CONCLUSION DLR is potentially more effective for image quality improvement and lung texture evaluation than hybrid-type IR on all radiation dose CTs obtained at HDCT and reconstructed with each section thickness with both matrixes for patients with a variety of pulmonary diseases.
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Affiliation(s)
- Nayu Hamabuchi
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Yoshiharu Ohno
- Department of Diagnostic Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
| | - Hirona Kimata
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Yuya Ito
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Kenji Fujii
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Naruomi Akino
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Daisuke Takenaka
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi, Hyogo, Japan
| | - Takeshi Yoshikawa
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi, Hyogo, Japan
| | - Yuka Oshima
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Takahiro Matsuyama
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hiroyuki Nagata
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hirotaka Ikeda
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Yoshiyuki Ozawa
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
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Ohno Y, Ozawa Y, Nagata H, Bando S, Cong S, Takahashi T, Oshima Y, Hamabuchi N, Matsuyama T, Ueda T, Yoshikawa T, Takenaka D, Toyama H. Area-Detector Computed Tomography for Pulmonary Functional Imaging. Diagnostics (Basel) 2023; 13:2518. [PMID: 37568881 PMCID: PMC10416899 DOI: 10.3390/diagnostics13152518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/22/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
An area-detector CT (ADCT) has a 320-detector row and can obtain isotropic volume data without helical scanning within an area of nearly 160 mm. The actual-perfusion CT data within this area can, thus, be obtained by means of continuous dynamic scanning for the qualitative or quantitative evaluation of regional perfusion within nodules, lymph nodes, or tumors. Moreover, this system can obtain CT data with not only helical but also step-and-shoot or wide-volume scanning for body CT imaging. ADCT also has the potential to use dual-energy CT and subtraction CT to enable contrast-enhanced visualization by means of not only iodine but also xenon or krypton for functional evaluations. Therefore, systems using ADCT may be able to function as a pulmonary functional imaging tool. This review is intended to help the reader understand, with study results published during the last a few decades, the basic or clinical evidence about (1) newly applied reconstruction methods for radiation dose reduction for functional ADCT, (2) morphology-based pulmonary functional imaging, (3) pulmonary perfusion evaluation, (4) ventilation assessment, and (5) biomechanical evaluation.
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Affiliation(s)
- Yoshiharu Ohno
- Department of Diagnostic Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan;
| | - Yoshiyuki Ozawa
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Hiroyuki Nagata
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan;
| | - Shuji Bando
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Shang Cong
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Tomoki Takahashi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Yuka Oshima
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Nayu Hamabuchi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Takahiro Matsuyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Takeshi Yoshikawa
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi 673-0021, Hyogo, Japan
| | - Daisuke Takenaka
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi 673-0021, Hyogo, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
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Wu D, Ren H, Li Q. Self-Supervised Dynamic CT Perfusion Image Denoising With Deep Neural Networks. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021. [DOI: 10.1109/trpms.2020.2996566] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Li JL, Ye WT, Yan LF, Liu ZY, Cao XM, Liang CH. Influence of tube voltage, tube current and newer iterative reconstruction algorithms in CT perfusion imaging in rabbit liver VX2 tumors. ACTA ACUST UNITED AC 2021; 26:264-270. [PMID: 32490833 DOI: 10.5152/dir.2019.19147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE We aimed to explore the influence of tube voltage, current and iterative reconstruction (IR) in computed tomography perfusion imaging (CTPI) and to compare CTPI parameters with microvessel density (MVD). METHODS Hepatic CTPI with three CTPI protocols (protocol A, tube voltage/current 80 kV/40 mAs; protocol B, tube voltage/current 80 kV/80 mAs; protocol C: tube voltage/current 100 kV/80 mAs) were performed in 25 rabbit liver VX2 tumor models, and filtered back projection (FBP) and IR were used for reconstruction of raw data. Hepatic arterial perfusion (HAP), hepatic portal perfusion (HPP), total perfusion (TP), hepatic arterial perfusion index (HPI), blood flow (BF) and blood volume (BV) of VX2 tumor and normal hepatic parenchyma were measured. Image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were quantified and radiation dose was recorded. MVD was counted using CD34 stain and compared with CTPI parameters. RESULTS The highest radiation dose was found in protocol C, followed by protocols B and A. IR lowered image noise and improved SNR and CNR in all three protocols. There was no statistical difference between HAP, HPP, TP, HPI, BF and BV of VX2 tumor and normal hepatic parenchyma among the three protocols (P > 0.05) with FBP or IR reconstruction, and no statistical difference between IR and FBP reconstruction (P > 0.05) in either protocol. MVD had a positive linear correlation with HAP, TP, BF, with best correlation observed with HAP; MVD of VX2 tumor showed no or poor correlation with HPI and BV. CONCLUSION CTPI parameters are not affected by tube voltage, current or reconstruction algorithm; HAP can best reflect MVD, but no correlation exists between BV and MVD.
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Affiliation(s)
| | | | | | | | | | - Chang-Hong Liang
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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Hasan AM, Mohebbian MR, Wahid KA, Babyn P. Hybrid-Collaborative Noise2Noise Denoiser for Low-Dose CT Images. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021. [DOI: 10.1109/trpms.2020.3002178] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Enjilela E, Lee TY, Wisenberg G, Teefy P, Bagur R, Islam A, Hsieh J, So A. Cubic-Spline Interpolation for Sparse-View CT Image Reconstruction With Filtered Backprojection in Dynamic Myocardial Perfusion Imaging. ACTA ACUST UNITED AC 2020; 5:300-307. [PMID: 31572791 PMCID: PMC6752292 DOI: 10.18383/j.tom.2019.00013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We investigated a projection interpolation method for reconstructing dynamic contrast-enhanced (DCE) heart images from undersampled x-ray projections with filtered backprojecton (FBP). This method may facilitate the application of sparse-view dynamic acquisition for ultralow-dose quantitative computed tomography (CT) myocardial perfusion (MP) imaging. We conducted CT perfusion studies on 5 pigs with a standard full-view acquisition protocol (984 projections). We reconstructed DCE heart images with FBP from all and a quarter of the measured projections evenly distributed over 360°. We interpolated the sparse-view (quarter) projections to a full-view setting using a cubic-spline interpolation method before applying FBP to reconstruct the DCE heart images (synthesized full-view). To generate MP maps, we used 3 sets of DCE heart images, and compared mean MP values and biases among the 3 protocols. Compared with synthesized full-view DCE images, sparse-view DCE images were more affected by streak artifacts arising from projection undersampling. Relative to the full-view protocol, mean bias in MP measurement associated with the sparse-view protocol was 10.0 mL/min/100 g (95%CI: −8.9 to 28.9), which was >3 times higher than that associated with the synthesized full-view protocol (3.3 mL/min/100 g, 95% CI: −6.7 to 13.2). The cubic-spline-view interpolation method improved MP measurement from DCE heart images reconstructed from only a quarter of the full projection set. This method can be used with the industry-standard FBP algorithm to reconstruct DCE images of the heart, and it can reduce the radiation dose of a whole-heart quantitative CT MP study to <2 mSv (at 8-cm coverage).
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Affiliation(s)
- Esmaeil Enjilela
- Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Ting-Yim Lee
- Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
| | - Gerald Wisenberg
- Department of Cardiology, London Health Sciences Centre, London, ON, Canada
| | - Patrick Teefy
- Department of Cardiology, London Health Sciences Centre, London, ON, Canada
| | - Rodrigo Bagur
- Department of Cardiology, London Health Sciences Centre, London, ON, Canada
| | - Ali Islam
- Department of Radiology, St. Joseph's Healthcare London, London, ON, Canada; and
| | - Jiang Hsieh
- Department of Molecular Imaging & Computed Tomography, GE Healthcare, Waukesha WI
| | - Aaron So
- Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
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Woisetschläger M, Henriksson L, Bartholomae W, Gasslander T, Björnsson B, Sandström P. Iterative reconstruction algorithm improves the image quality without affecting quantitative measurements of computed tomography perfusion in the upper abdomen. Eur J Radiol Open 2020; 7:100243. [PMID: 32642503 PMCID: PMC7334814 DOI: 10.1016/j.ejro.2020.100243] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 12/26/2022] Open
Abstract
Iterative image-reconstruction algorithm (ADMIRE) did not affect the quantitative measurements in CT perfusion. Iterative image-reconstruction algorithm (ADMIRE) did not affect the time attenuation curves in CT perfusion. Image noise was lower, but the SNR was higher, for iterative reconstructions in CT perfusion examinations with higher strength of noise reduction.
Objective To investigate differences between reconstruction algorithms in quantitative perfusion values and time-attenuation curves in computed tomography perfusion (CTP) examinations of the upper abdomen. Methods Twenty-six CTP examinations were reconstructed with filtered back projection and an iterative reconstruction algorithm, advanced modeled iterative reconstruction (ADMIRE), with different levels of noise-reduction strength. Using the maximum-slope model, quantitative measurements were obtained: blood flow (mL/min/100 mL), blood volume (mL/100 mL), time to peak (s), arterial liver perfusion (mL/100 mL/min), portal venous liver perfusion (mL/100 mL/min), hepatic perfusion index (%), temporal maximum intensity projection (Hounsfield units (HU)) and temporal average HU. Time-attenuation curves for seven sites (left liver lobe, right liver lobe, hepatocellular carcinoma, spleen, gastric wall, pancreas, portal vein) were obtained. Mixed-model analysis was used for statistical evaluation. Image noise and the signal:noise ratio (SNR) were compared between four reconstructions, and statistical analysis of these reconstructions was made with a related-samples Friedman’s two-way analysis of variance by ranks test. Results There were no significant differences for quantitative measurements between the four reconstructions for all tissues. There were no significant differences between the AUC values of the time-attenuation curves between the four reconstructions for all tissues, including three automatic measurements (portal vein, aorta, spleen). There was a significant difference in image noise and SNR between the four reconstructions. Conclusions ADMIRE did not affect the quantitative measurements or time-attenuation curves of tissues in the upper abdomen. The image noise was lower, and the SNR higher, for iterative reconstructions with higher noise-reduction strengths.
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Key Words
- 4D computed tomography
- ADMIRE, advanced modelled iterative reconstruction
- ALP, arterial liver perfusion
- AUC, area under the curve
- Abdomen
- BF, blood flow
- BMI, body mass index
- BV, blood volume
- CTP, computed tomography perfusion
- FBP, filtered back projection
- GFR, glomerular filtration rate
- HCC, hepatocellular carcinoma
- HPI, hepatic perfusion index
- Image reconstruction
- LI-RADS-5, liver imaging reporting and data system
- Liver
- PVP, portal venous liver perfusion
- Perfusion
- Radiation dosage
- SNR, signal to noise ratio
- TAC, time attenuation curve
- TACE, transarterial chemoembolization
- TTP, time to peak
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Affiliation(s)
- Mischa Woisetschläger
- Department of Radiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Lilian Henriksson
- Department of Radiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Wolf Bartholomae
- Department of Radiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Thomas Gasslander
- Department of Surgery in Linköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Bergthor Björnsson
- Department of Surgery in Linköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Per Sandström
- Department of Surgery in Linköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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Ippolito D, Pecorelli A, Querques G, Drago SG, Maino C, Franzesi CT, Hatzidakis A, Sironi S. Dynamic Computed Tomography Perfusion Imaging: Complementary Diagnostic Tool in Hepatocellular Carcinoma Assessment From Diagnosis to Treatment Follow-up. Acad Radiol 2019; 26:1675-1685. [PMID: 30852079 DOI: 10.1016/j.acra.2019.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/13/2019] [Accepted: 02/13/2019] [Indexed: 02/05/2023]
Abstract
Early diagnosis of HCC is of paramount importance in order to enable the application of curative treatments. Among these, radiofrequency ablation (RFA) is actually considered the most effective ablative therapy for early stage hepatocellular carcinoma (HCC) not suitable for surgery. On the other hand, transarterial chemoembolization (TACE) represents the standard of care for intermediate stage HCC and compensated liver function. Finally, sorafenib, an oral antiangiogenic targeted drug, is the only approved systemic therapy for advanced HCC with vascular invasion, extrahepatic spread, and well-preserved liver function. Beside traditional radiological techniques, new functional imaging tools have been introduced in order to provide not only morphological information but also quantitative functional data. In this review, we analyze perfusion-CT (pCT) from a technical point of view, describing the main different mathematical analytical models for the quantification of tissue perfusion from acquired CT raw data, the most commonly acquired perfusion parameters, and the technical parameters required to perform a standard pCT examination. Moreover, a systematic review of the literature was performed to assess the role of pCT as an emerging imaging biomarker for HCC diagnosis, response evaluation to RFA, TACE, and sorafenib, and we examine its challenges in HCC management.
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Affiliation(s)
- Davide Ippolito
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, San Gerardo Hospital, Via Pergolesi 33 - 20900 Monza, Italy
| | - Anna Pecorelli
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, San Gerardo Hospital, Via Pergolesi 33 - 20900 Monza, Italy.
| | - Giulia Querques
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, San Gerardo Hospital, Via Pergolesi 33 - 20900 Monza, Italy
| | - Silvia Girolama Drago
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, San Gerardo Hospital, Via Pergolesi 33 - 20900 Monza, Italy
| | - Cesare Maino
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, San Gerardo Hospital, Via Pergolesi 33 - 20900 Monza, Italy
| | - Cammillo Talei Franzesi
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, San Gerardo Hospital, Via Pergolesi 33 - 20900 Monza, Italy
| | - Adam Hatzidakis
- Department of Medical Imaging, University Hospital of Heraklion, Greece
| | - Sandro Sironi
- University of Milano-Bicocca, Milan, Italy; Department of Diagnostic Radiology, ASST Papa Giovanni XXIII, Bergamo, Italy
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Higaki T, Nakamura Y, Fukumoto W, Honda Y, Tatsugami F, Awai K. Clinical application of radiation dose reduction at abdominal CT. Eur J Radiol 2019; 111:68-75. [DOI: 10.1016/j.ejrad.2018.12.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/08/2018] [Accepted: 12/17/2018] [Indexed: 02/07/2023]
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Enjilela E, Lee TY, Hsieh J, Murjoomdar A, Stewart E, Dekaban M, Su F, So A. Ultra-Low-Dose Sparse-View Quantitative CT Liver Perfusion Imaging. ACTA ACUST UNITED AC 2018; 3:175-179. [PMID: 30042980 PMCID: PMC6024390 DOI: 10.18383/j.tom.2017.00018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Radiation dose of computed tomography liver perfusion imaging can be reduced by collecting fewer x-ray projections in each gantry rotation, but the resulting aliasing artifacts could affect the hepatic perfusion measurement. We investigated the effect of projection undersampling on the assessment of hepatic arterial blood flow (HABF) in hepatocellular carcinoma (HCC) when dynamic contrast-enhanced (DCE) liver images were reconstructed with filtered backprojection (FBP) and compressed sensing (CS). DCE liver images of a patient with HCC acquired with a 64-row CT scanner were reconstructed from all the measured projections (984-view) with the standard FBP and from one-third (328-view) and one-fourth (246-view) of all available projections with FBP and CS. Each of the 5 sets of DCE liver images was analyzed with a model-based deconvolution algorithm from which HABF maps were generated and compared. Mean HABF in the tumor and normal tissue measured by the 328-view CS and FBP protocols was within 5% differences from that assessed by the reference full-view FBP protocol. In addition, the tumor size measured by using the 328-view CS and FBP average images was identical to that determined by using the full-view FBP average image. By contrast, both the 246-view CS and FBP protocols exhibited larger differences (>20%) in anatomical and functional assessments compared with the full-view FBP protocol. The preliminary results suggested that computed tomography perfusion imaging in HCC could be performed with 3 times less projection measurement than the current full-view protocol (67% reduction in radiation dose) when either FBP or CS was used for image reconstruction.
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Affiliation(s)
- Esmaeil Enjilela
- Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada
| | - Ting-Yim Lee
- Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada.,Imaging Program, Lawson Health Research Institute, London, ON, Canada
| | | | - Amol Murjoomdar
- Department of Medical Imaging, Western University, London, ON, Canada; and
| | - Errol Stewart
- Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada
| | - Mark Dekaban
- Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada
| | - Feng Su
- Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada
| | - Aaron So
- Imaging Program, Lawson Health Research Institute, London, ON, Canada
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Seyyedi S, Liapi E, Lasser T, Ivkov R, Hatwar R, Stayman JW. Low-Dose CT Perfusion of the Liver using Reconstruction of Difference. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018; 2:205-214. [PMID: 29785411 DOI: 10.1109/trpms.2018.2812360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Liver CT perfusion (CTP) is used in the detection, staging, and treatment response analysis of hepatic diseases. Unfortunately, CTP radiation exposures is significant, limiting more widespread use. Traditional CTP data processing reconstructs individual temporal samples, ignoring a large amount of shared anatomical information between temporal samples, suggesting opportunities for improved data processing. We adopt a prior-image-based reconstruction approach called Reconstruction of Difference (RoD) to enable low-exposure CTP acquisition. RoD differs from many algorithms by directly estimating the attenuation changes between the current patient state and a prior CT volume. We propose to use a high-fidelity unenhanced baseline CT image to integrate prior anatomical knowledge into subsequent data reconstructions. Using simulation studies based on a 4D digital anthropomorphic phantom with realistic time-attenuation curves, we compare RoD with conventional filtered-backprojection, penalized-likelihood estimation, and prior image penalized-likelihood estimation. We evaluate each method in comparisons of reconstructions at individual time points, accuracy of estimated time-attenuation curves, and in an analysis of common perfusion metric maps including hepatic arterial perfusion, hepatic portal perfusion, perfusion index, and time-to-peak. Results suggest that RoD enables significant exposure reductions, outperforming standard and more sophisticated model-based reconstruction, making RoD a potentially important tool to enable low-dose liver CTP.
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Affiliation(s)
- Saeed Seyyedi
- Computer Aided Medical Procedures and Chair of Biomedical Physics, Technical University of Munich, Munich, 85748 Germany
| | - Eleni Liapi
- Department of Radiology and Radiological Sciences, Johns Hopkins Hospital, Baltimore, MD 21205 USA
| | - Tobias Lasser
- Computer Aided Medical Procedures, Technical University of Munich, Munich, 85748 Germany
| | - Robert Ivkov
- Department of Radiation Oncology, Johns Hopkins Hospital, Baltimore, MD 21205 USA
| | - Rajeev Hatwar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21205 USA
| | - J Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205 USA
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12
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Enjilela E, Lee TY, Hsieh J, Wisenberg G, Teefy P, Yadegari A, Bagur R, Islam A, Branch K, So A. Ultra-low dose quantitative CT myocardial perfusion imaging with sparse-view dynamic acquisition and image reconstruction: A feasibility study. Int J Cardiol 2018; 254:272-281. [DOI: 10.1016/j.ijcard.2017.11.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/24/2017] [Accepted: 11/10/2017] [Indexed: 12/30/2022]
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Prezzi D, Goh V, Virdi S, Mallett S, Grierson C, Breen D. Adaptive statistical iterative reconstruction improves image quality without affecting perfusion CT quantitation in primary colorectal cancer. Eur J Radiol Open 2017; 4:69-74. [PMID: 28616448 PMCID: PMC5458094 DOI: 10.1016/j.ejro.2017.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/22/2017] [Accepted: 05/22/2017] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVES To determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR) on perfusion CT (pCT) parameter quantitation and image quality in primary colorectal cancer. METHODS Prospective observational study. Following institutional review board approval and informed consent, 32 patients with colorectal adenocarcinoma underwent pCT (100 kV, 150 mA, 120 s acquisition, axial mode). Tumour regional blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined using identical regions-of-interests for ASIR percentages of 0%, 20%, 40%, 60%, 80% and 100%. Image noise, contrast-to-noise ratio (CNR) and pCT parameters were assessed across ASIR percentages. Coefficients of variation (CV), repeated measures analysis of variance (rANOVA) and Spearman' rank order correlation were performed with statistical significance at 5%. RESULTS With increasing ASIR percentages, image noise decreased by 33% while CNR increased by 61%; peak tumour CNR was greater than 1.5 with 60% ASIR and above. Mean BF, BV, MTT and PS differed by less than 1.8%, 2.9%, 2.5% and 2.6% across ASIR percentages. CV were 4.9%, 4.2%, 3.3% and 7.9%; rANOVA P values: 0.85, 0.62, 0.02 and 0.81 respectively. CONCLUSIONS ASIR improves image noise and CNR without altering pCT parameters substantially.
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Affiliation(s)
- D. Prezzi
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, 4th Floor, Lambeth Wing, St. Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, United Kingdom
| | - V. Goh
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, 4th Floor, Lambeth Wing, St. Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, United Kingdom
| | - S. Virdi
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, 4th Floor, Lambeth Wing, St. Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, United Kingdom
| | - S. Mallett
- Institute of Applied Health Research, University of Birmingham, United Kingdom
| | - C. Grierson
- University Hospital Southampton NHS Foundation Trust, United Kingdom
| | - D.J. Breen
- University Hospital Southampton NHS Foundation Trust, United Kingdom
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Topcuoğlu OM, Karçaaltıncaba M, Akata D, Özmen MN. Reproducibility and variability of very low dose hepatic perfusion CT in metastatic liver disease. Diagn Interv Radiol 2017; 22:495-500. [PMID: 27759566 DOI: 10.5152/dir.2016.16612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE We aimed to determine the intra- and interobserver agreement on the software analysis of very low dose hepatic perfusion CT (pCT). METHODS A total of 53 pCT examinations were obtained from 21 patients (16 men, 5 women; mean age, 60.4 years) with proven liver metastasis from various primary cancers. The pCT examinations were analyzed by two readers independently and perfusion parameters were noted for whole liver, whole metastasis, metastasis wall, and normal-looking liver (liver tissue without metastasis) in regions of interest (ROIs). Readers repeated the analysis after an interval of one month. Intra- and interobserver agreements were assessed with intraclass correlation coefficients (ICC) and Bland-Altman statistics. RESULTS The mean ICCs of all ROIs between readers were 0.91, 0.93, 0.86, 0.45, 0.53, and 0.66 for blood flow (BF), blood volume (BV), permeability, arterial liver perfusion (ALP), portal venous perfusion (PVP) and hepatic perfusion index (HPI), respectively. The mean ICCs of all ROIs between readings were 0.86, 0.91, 0.81, 0.53, 0.56, and 0.71 for BF, BV, permeability, ALP, PVP, and HPI, respectively. There was greater agreement on the parameters measured for the whole metastasis than on the parameters measured for the metastasis wall. The effective dose of all perfusion CT studies was 2.9 mSv. CONCLUSION There is greater intra- and interobserver agreement for BF and BV than for permeability, ALP, PVP, and HPI at very low dose hepatic pCT. Permeability, ALP, PVP, and HPI parameters cannot be used in clinical practice for hepatic pCT with an effective dose of 2.9 mSv.
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Is CT perfusion ready for liver cancer treatment evaluation? J Am Coll Radiol 2015; 12:111-3. [PMID: 25557575 DOI: 10.1016/j.jacr.2014.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 01/06/2023]
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Mirsadraee S, Weir N, Connolly S, Murchison J, Reid J, Hirani N, Connell M, van Beek E. Feasibility of radiation dose reduction using AIDR-3D in dynamic pulmonary CT perfusion. Clin Radiol 2015; 70:844-51. [DOI: 10.1016/j.crad.2015.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/20/2015] [Accepted: 04/17/2015] [Indexed: 01/05/2023]
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Geyer LL, Schoepf UJ, Meinel FG, Nance JW, Bastarrika G, Leipsic JA, Paul NS, Rengo M, Laghi A, De Cecco CN. State of the Art: Iterative CT Reconstruction Techniques. Radiology 2015. [PMID: 26203706 DOI: 10.1148/radiol.2015132766] [Citation(s) in RCA: 398] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Lucas L Geyer
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - U Joseph Schoepf
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Felix G Meinel
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - John W Nance
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Gorka Bastarrika
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Jonathon A Leipsic
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Narinder S Paul
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Marco Rengo
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Andrea Laghi
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
| | - Carlo N De Cecco
- From the Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226, 25 Courtenay Dr, Charleston, SC 29425 (L.L.G., U.J.S., F.G.M., J.W.N., C.N.D.); Department of Radiology, Sunnybrook Health Sciences Centre, Toronto, Ont, Canada (G.B.); Department of Radiology, University of British Columbia, Vancouver, BC, Canada (J.A.L.); Department of Radiology, Toronto General Hospital, University of Toronto, Toronto, Ont, Canada (N.S.P.); and Department of Radiological Sciences, Oncology and Pathology, University of Rome Sapienza-Polo Pontino, Latina, Italy (M.R., A.L., C.N.D.)
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Zhang CY, Cui YF, Guo C, Cai J, Weng YF, Wang LJ, Wang DB. Low contrast medium and radiation dose for hepatic computed tomography perfusion of rabbit VX2 tumor. World J Gastroenterol 2015; 21:5259-5270. [PMID: 25954099 PMCID: PMC4419066 DOI: 10.3748/wjg.v21.i17.5259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 01/18/2015] [Accepted: 02/11/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography (CT) perfusion of rabbit VX2 tumor.
METHODS: Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning with a 24-h interval between a conventional tube potential (120 kVp) protocol with 350 mgI/mL contrast medium and filtered back projection, and a low tube potential (80 kVp) protocol with 270 mgI/mL contrast medium with iterative reconstruction. Correlation and agreement among perfusion parameters acquired by the conventional and low dose protocols were assessed for the viable tumor component as well as whole tumor. Image noise and tumor-to-liver contrast to noise ratio during arterial and portal venous phases were evaluated.
RESULTS: A 38% reduction in contrast medium dose (360.1 ± 13.3 mgI/kg vs 583.5 ± 21.5 mgI/kg, P < 0.001) and a 73% decrease in radiation dose (1898.5 mGy • cm vs 6951.8 mGy • cm) were observed. Interestingly, there was a strong positive correlation in hepatic arterial perfusion (r = 0.907, P < 0.001; r = 0.879, P < 0.001), hepatic portal perfusion (r = 0.819, P = 0.002; r = 0.831, P = 0.002), and hepatic blood flow (r = 0.945, P < 0.001; r = 0.930, P < 0.001) as well as a moderate correlation in hepatic perfusion index (r = 0.736, P = 0.01; r = 0.636, P = 0.035) between the low dose protocol with iterative reconstruction and the conventional protocol for the viable tumor component and the whole tumor. These two imaging protocols provided a moderate but acceptable agreement for perfusion parameters and similar tumor-to-liver CNR during arterial and portal venous phases (5.63 ± 2.38 vs 6.16 ± 2.60, P = 0.814; 4.60 ± 1.27 vs 5.11 ± 1.74, P = 0.587).
CONCLUSION: Compared with the conventional protocol, low contrast medium and radiation dose with iterative reconstruction has no significant influence on hepatic perfusion parameters for rabbits VX2 tumor.
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CT Liver Imaging: What is New? CURRENT RADIOLOGY REPORTS 2015. [DOI: 10.1007/s40134-015-0088-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Kim SH, Kamaya A, Willmann JK. CT perfusion of the liver: principles and applications in oncology. Radiology 2014; 272:322-44. [PMID: 25058132 DOI: 10.1148/radiol.14130091] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
With the introduction of molecularly targeted chemotherapeutics, there is an increasing need for defining new response criteria for therapeutic success because use of morphologic imaging alone may not fully assess tumor response. Computed tomographic (CT) perfusion imaging of the liver provides functional information about the microcirculation of normal parenchyma and focal liver lesions and is a promising technique for assessing the efficacy of various anticancer treatments. CT perfusion also shows promising results for diagnosing primary or metastatic tumors, for predicting early response to anticancer treatments, and for monitoring tumor recurrence after therapy. Many of the limitations of early CT perfusion studies performed in the liver, such as limited coverage, motion artifacts, and high radiation dose of CT, are being addressed by recent technical advances. These include a wide area detector with or without volumetric spiral or shuttle modes, motion correction algorithms, and new CT reconstruction technologies such as iterative algorithms. Although several issues related to perfusion imaging-such as paucity of large multicenter trials, limited accessibility of perfusion software, and lack of standardization in methods-remain unsolved, CT perfusion has now reached technical maturity, allowing for its use in assessing tumor vascularity in larger-scale prospective clinical trials. In this review, basic principles, current acquisition protocols, and pharmacokinetic models used for CT perfusion imaging of the liver are described. Various oncologic applications of CT perfusion of the liver are discussed and current challenges, as well as possible solutions, for CT perfusion are presented.
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Affiliation(s)
- Se Hyung Kim
- From the Department of Radiology, Molecular Imaging Program at Stanford, School of Medicine, Stanford University, 300 Pasteur Dr, Room H1307, Stanford, CA 94305-5621 (S.H.K., A.K., J.K.W.); and Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, Seoul, Korea (S.H.K.)
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Pushing CT and MR imaging to the molecular level for studying the "omics": current challenges and advancements. BIOMED RESEARCH INTERNATIONAL 2014; 2014:365812. [PMID: 24738056 PMCID: PMC3971568 DOI: 10.1155/2014/365812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/26/2013] [Accepted: 01/24/2014] [Indexed: 12/24/2022]
Abstract
During the past decade, medical imaging has made the transition from anatomical imaging to functional and even molecular imaging. Such transition provides a great opportunity to begin the integration of imaging data and various levels of biological data. In particular, the integration of imaging data and multiomics data such as genomics, metabolomics, proteomics, and pharmacogenomics may open new avenues for predictive, preventive, and personalized medicine. However, to promote imaging-omics integration, the practical challenge of imaging techniques should be addressed. In this paper, we describe key challenges in two imaging techniques: computed tomography (CT) and magnetic resonance imaging (MRI) and then review existing technological advancements. Despite the fact that CT and MRI have different principles of image formation, both imaging techniques can provide high-resolution anatomical images while playing a more and more important role in providing molecular information. Such imaging techniques that enable single modality to image both the detailed anatomy and function of tissues and organs of the body will be beneficial in the imaging-omics field.
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Dong Y, Lei GW, Wang SW, Zheng SW, Ge Y, Wei FC. Diagnostic value of CT perfusion imaging for parotid neoplasms. Dentomaxillofac Radiol 2013; 43:20130237. [PMID: 24186883 DOI: 10.1259/dmfr.20130237] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To assess the value of CT perfusion imaging in the differentiation of different histological categorization of benign tumours from malignant tumours in patients with parotid neoplasms. METHODS CT perfusion was successfully performed in 62 patients with parotid neoplasms whose diagnoses were confirmed by surgery or biopsy. The software generated a tissue time-density curve (TDC) and measured blood volume, blood flow, mean transit time and capillary permeability surface product. One-way ANOVA and receiver operating characteristic curves were used to analyse the difference and diagnostic efficacies of all perfusion data between each one of the benign tumours and malignancies. Statistical significance was assigned at the 5% level. RESULTS Pleomorphic adenomas mainly had a gradually ascending TDC. Warthin tumours showed a fast ascent followed by a fast descent. The TDC of basal cell adenomas had a fast ascension followed by a plateau, then a gradual descent. Malignant tumours mainly showed a rapidly ascending curve with a stable plateau. Significant differences were observed in blood flow, blood volume and mean transit time between pleomorphic adenomas and malignant tumours (p < 0.05) as well as in blood flow and blood volume between the Warthin tumours, the basal cell adenomas and the malignant tumours (p < 0.05). Differences in permeability surface between the basal cell adenomas and malignant tumours were significant (p < 0.01). CONCLUSION CT perfusion of parotid gland could provide TDC and perfusion data, which were useful in the differentiation of different histological benign tumours and malignant tumours in the parotid gland.
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Affiliation(s)
- Y Dong
- Department of Radiology, the First Affiliated Hospital of Dalian Medical University, Dalian, China
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Fuentes-Orrego JM, Hayano K, Kambadakone AR, Hahn PF, Sahani DV. Dose-modified 256-MDCT of the abdomen using low tube current and hybrid iterative reconstruction. Acad Radiol 2013; 20:1405-12. [PMID: 24119353 DOI: 10.1016/j.acra.2013.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 01/29/2023]
Abstract
RATIONALE AND OBJECTIVES To evaluate the performance of hybrid iterative reconstruction technique (h-IRT) on image quality (IQ) in abdominal dose-modified (DM) scans in phantom and in patients in comparison to filtered back projection (FBP). MATERIALS AND METHODS An anthropomorphic phantom was scanned using various kVp (80-140) and mAs (25-100) settings. Images were reconstructed with FBP and h-IRT levels (1-6). In 69 adults (59.6 ± 13.54 years; 20 male, 49 female), DM computed tomography (CT) scans were performed using 120 kVp and 100-120 mAs. In 25/69, 5-mm FBP and h-IRT (levels 1-4 and 5) images were analyzed to validate IQ. The subsequent 44/69 had FBP and h-IRT (level 4) images reconstructed. Two readers evaluated 188 image series for IQ, noise, and artifacts. Objective and subjective data were analyzed using t-test and Wilcoxon signed-rank test, respectively. In 46/69 patients, prior dose CT was available for dose comparison. RESULTS In the phantom, noise reduction ranged from 12% (h-IRT level 1) to 50% (level 6). In patients, h-IRT level 4 images were rated diagnostic in 69/69 exams but DM-FBP images were found nondiagnostic in 20/69 patients. The size-specific dose estimate (SSDE) was reduced by 55% in the dose-modified CT group, (SSDE:4.55 ± 1.15 mGy) over the prior dose protocol (SSDE:10.21 ± 3.5 mGy, P < .0001). CONCLUSION h-IRT improved IQ in abdominal DM-CT scans in phantom and in patients. Dose improvements were greater in smaller patients than larger ones.
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Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging. Eur Radiol 2013; 24:151-61. [PMID: 23995880 DOI: 10.1007/s00330-013-2992-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/11/2013] [Accepted: 07/28/2013] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. METHODS Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. RESULTS Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. CONCLUSION Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. KEY POINTS • Four-dimensional computed tomography is limited by motion artefacts and poor image quality. • Time-resolved-CT facilitates 4D-CT data visualisation, segmentation and analysis by condensing raw data. • Time-resolved CT demonstrates better image quality than raw data images. • Time-resolved CT improves detection of arterialised liver lesions in cirrhotic patients.
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Schultz K, George E, Mullen KM, Steigner ML, Mitsouras D, Bueno EM, Pomahac B, Rybicki FJ, Kumamaru KK. Reduced radiation exposure for face transplant surgical planning computed tomography angiography. PLoS One 2013; 8:e63079. [PMID: 23638180 PMCID: PMC3637203 DOI: 10.1371/journal.pone.0063079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/28/2013] [Indexed: 12/21/2022] Open
Abstract
Objective To test the hypothesis that wide area detector face transplant surgical planning CT angiograms with simulated lower radiation dose and iterative reconstruction (AIDR3D) are comparable in image quality to those with standard tube current and filtered back projection (FBP) reconstruction. Materials and Methods The sinograms from 320-detector row CT angiography of four clinical candidates for face transplantation were processed utilizing standard FBP, FBP with simulated 75, 62, and 50% tube current, and AIDR3D with corresponding dose reduction. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured at muscle, fat, artery, and vein. Image quality for each reconstruction strategy was assessed by two independent readers using a 4-point scale. Results Compared to FBP, the median SNR and CNR for AIDR3D images were higher at all sites for all 4 different tube currents. The AIDR3D with simulated 50% tube current achieved comparable SNR and CNR to FBP with standard dose (median muscle SNR: 5.77 vs. 6.23; fat SNR: 6.40 vs. 5.75; artery SNR: 43.8 vs. 45.0; vein SNR: 54.9 vs. 55.7; artery CNR: 38.1 vs. 38.6; vein CNR: 49.0 vs. 48.7; all p-values >0.19). The interobserver agreement in the image quality score was good (weighted κ = 0.7). The overall score and the scores for smaller arteries were significantly lower when FBP with 50% dose reduction was used. The AIDR3D reconstruction images with 4 different simulated doses achieved a mean score ranging from 3.68 to 3.82 that were comparable to the scores from images reconstructed using FBP with original dose (3.68–3.77). Conclusions Simulated radiation dose reduction applied to clinical CT angiography for face transplant planning suggests that AIDR3D allows for a 50% reduction in radiation dose, as compared to FBP, while preserving image quality.
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Affiliation(s)
- Kurt Schultz
- Toshiba Medical Research Institute USA, Vernon Hills, Illinois, United States of America
| | - Elizabeth George
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Katherine M. Mullen
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael L. Steigner
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dimitrios Mitsouras
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ericka M. Bueno
- Department of Surgery, Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Bohdan Pomahac
- Department of Surgery, Division of Plastic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - Frank J. Rybicki
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Kanako K. Kumamaru
- Applied Imaging Science Laboratory, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
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Computed Tomography (CT) Perfusion in Abdominal Cancer: Technical Aspects. Diagnostics (Basel) 2013; 3:261-70. [PMID: 26835679 PMCID: PMC4665537 DOI: 10.3390/diagnostics3020261] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 03/21/2013] [Accepted: 03/25/2013] [Indexed: 12/22/2022] Open
Abstract
Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed table position. Advances in reconstruction algorithms make it possible to reduce the radiation dose for each examination to acceptable levels. Regarding abdominal imaging, CT perfusion is still considered a research tool, but several studies have proven it as a reliable non-invasive technique for assessment of vascularity. CT perfusion has also been used for tumor characterization, staging of disease, response evaluation of newer drugs targeted towards angiogenesis and as a method for early detection of recurrence after radiation and embolization. There are several software solutions available on the market today based on different perfusion algorithms. However, there is no consensus on which protocol and algorithm to use for specific organs. In this article, the authors give an introduction to CT perfusion in abdominal imaging introducing technical aspects for calculation of perfusion parameters, and considerations on patient preparation. This article also contains clinical cases to illustrate the use of CT perfusion in abdominal imaging.
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Chen MY, Steigner ML, Leung SW, Kumamaru KK, Schultz K, Mather RT, Arai AE, Rybicki FJ. Simulated 50 % radiation dose reduction in coronary CT angiography using adaptive iterative dose reduction in three-dimensions (AIDR3D). Int J Cardiovasc Imaging 2013; 29:1167-75. [PMID: 23404384 PMCID: PMC3701132 DOI: 10.1007/s10554-013-0190-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 01/28/2013] [Indexed: 11/06/2022]
Abstract
To compare the image quality of coronary CT angiography (CTA) studies between standard filtered back projection (FBP) and adaptive iterative dose reduction in three-dimensions (AIDR3D) reconstruction using CT noise additional software to simulate reduced radiation exposure. Images from 93 consecutive clinical coronary CTA studies were processed utilizing standard FBP, FBP with 50 % simulated dose reduction (FBP50 %), and AIDR3D with simulated 50 % dose reduction (AIDR50 %). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured within 5 regions-of-interest, and image quality for each reconstruction strategy was assessed by two independent readers using a 4-point scale. Compared to FBP, the SNR measured from the AIDR50 % images was similar or higher (airway: 38.3 ± 12.7 vs. 38.5 ± 14.5, p = 0.81, fat: 5.5 ± 1.9 vs. 5.4 ± 2.0, p = 0.20, muscle: 3.2 ± 1.2 vs. 3.1 ± 1.3, p = 0.38, aorta: 22.6 ± 9.4 vs. 20.2 ± 9.7, p < 0.0001, liver: 2.7 ± 1.0 vs. 2.3 ± 1.1, p < 0.0001), while the SNR of the FBP50 % images were all lower (p values < 0.0001). The CNR measured from AIDR50 % images was also higher than that from the FBP images for the aorta relative to muscle (20.5 ± 9.0 vs. 18.3 ± 9.2, p < 0.0001). The interobserver agreement in the image quality score was excellent (κ = 0.82). The quality score was significantly higher for the AIDR50 % images compared to the FBP images (3.6 ± 0.6 vs. 3.3 ± 0.7, p = 0.004). Simulated radiation dose reduction applied to clinical coronary CTA images suggests that a 50 % reduction in radiation dose can be achieved with adaptive iterative dose reduction software with image quality that is at least comparable to images acquired at standard radiation exposure and reconstructed with filtered back projection.
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Affiliation(s)
- Marcus Y Chen
- Advanced Cardiovascular Imaging Laboratory, Cardiovascular and Pulmonary Branch, Department of Health and Human Services, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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