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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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Perisinakis K, Tzedakis A, Pouli S, Spanakis K, Hatzidakis A, Damilakis J. Comparison of patient dose from routine multi-phase and dynamic liver perfusion CT studies taking into account the effect of iodinated contrast administration. Eur J Radiol 2019; 110:39-44. [PMID: 30599871 DOI: 10.1016/j.ejrad.2018.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 11/15/2018] [Accepted: 11/18/2018] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To accurately determine and compare patient radiation burden from routine multi-phase CT (MPCT) and dynamic CT liver perfusion (CTLP) studies taking into account the effect of iodine uptake of exposed tissues/organs. MATERIALS AND METHODS 40 consecutive MPCT of upper abdomen and 40 consecutive CTLP studies performed on a modern CT scanner were retrospectively studied. Iodine uptake of radiosensitive tissues at the time of acquisition was calculated through the difference of tissues' CT numbers between NECT and CECT images. Monte Carlo simulation and mathematical anthropomorphic phantoms were employed to derive patient-size-specific organ dose data from each scan involved taking into account the effect of iodinated contrast uptake on absorbed dose. Effective dose estimates were derived for routine multiphase CT and CTLP by summing up the contribution of NECT and CECT scans involved. RESULTS The mean underestimation error in organ doses from CECT exposures if iodine uptake is not encountered was found to be 2.2%-38.9%. The effective dose to an average-size patient from routine 3-phase CT, 4-phase CT and CTLP studies was found to be 20.6, 27.7 and 25.8 mSv, respectively. Effective dose from CTLP was found lower than 4-phase CT of upper abdomen irrespective of patient body size. Compared to 3-phase CT, the radiation burden from CTLP was found to be higher for average size-patients but again lower for overweight patients. CONCLUSIONS Modern CT technology allows CTLP studies at comparable or even lower patient radiation burden compared to routine multi-phase liver CT imaging.
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Affiliation(s)
- Kostas Perisinakis
- Department of Medical Physics, Medical School, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece; Department of Medical Physics, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece.
| | - Antonis Tzedakis
- Department of Medical Physics, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece
| | - Styliani Pouli
- Department of Radiology, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece
| | - Kostas Spanakis
- Department of Radiology, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece
| | - Adam Hatzidakis
- Department of Radiology, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece; Department of Radiology, Medical School, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece
| | - John Damilakis
- Department of Medical Physics, Medical School, University of Crete, P.O. Box 2208, Heraklion 71003, Crete, Greece; Department of Medical Physics, University Hospital of Heraklion, P.O. Box 1352, Heraklion 71110, Crete, Greece
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Kim SY, Cho JY, Lee J, Hwang SI, Moon MH, Lee EJ, Hong SS, Kim CK, Kim KA, Park SB, Sung DJ, Kim Y, Kim YM, Jung SI, Rha SE, Kim DW, Lee H, Shim Y, Hwang I, Woo S, Choi HJ. Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography. Korean J Radiol 2018; 19:1119-1129. [PMID: 30386143 PMCID: PMC6201985 DOI: 10.3348/kjr.2018.19.6.1119] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 06/07/2018] [Indexed: 01/29/2023] Open
Abstract
Objective To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and Methods This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.
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Affiliation(s)
- Sang Youn Kim
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jeong Yeon Cho
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.,Institute of Radiation Medicine and Kidney Research Institute, Seoul National University, Seoul 03080, Korea
| | - Joongyub Lee
- Medical Research Collaborating Center, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sung Il Hwang
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam 13621, Korea
| | - Min Hoan Moon
- Department of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul 07061, Korea
| | - Eun Ju Lee
- Department of Radiology, Ajou University Hospital, Ajou University School of Medicine, Suwon 16499, Korea
| | - Seong Sook Hong
- Department of Radiology, Soonchunhyang University Seoul Hospital, Seoul 04401, Korea
| | - Chan Kyo Kim
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Kyeong Ah Kim
- Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul 08308, Korea
| | - Sung Bin Park
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06973, Korea
| | - Deuk Jae Sung
- Department of Radiology, Korea University Anam Hospital, Korea University College of Medicine, Seoul 02841, Korea
| | - Yongsoo Kim
- Department of Radiology, Hanyang University Guri Hospital, Guri 11923, Korea
| | - You Me Kim
- Department of Radiology, Dankook University Hospital, Dankook University College of Medicine, Cheonan 31116, Korea
| | - Sung Il Jung
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - Sung Eun Rha
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Dong Won Kim
- Department of Radiology, Dong-A University College of Medicine, Busan 49201, Korea
| | - Hyun Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang 14068, Korea
| | - Youngsup Shim
- Department of Radiology, Gachon University, Gil Medical Center, Incheon 21565, Korea
| | - Inpyeong Hwang
- Department of Radiology, Cheongyang-gun Health Center and County Hospital, Cheongyang 33324, Korea
| | - Sungmin Woo
- Department of Radiology, Armed Forces Daejeon Hospital, Daejeon 34059, Korea
| | - Hyuck Jae Choi
- Department of Radiology, Sheikh Khalifa Specialty Hospital, Ras al Khaimah, UAE
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The feasibility of low-concentration contrast and low tube voltage in computed tomography perfusion imaging: an animal study. Biosci Rep 2018; 38:BSR20170977. [PMID: 29208767 PMCID: PMC6435459 DOI: 10.1042/bsr20170977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 11/23/2017] [Accepted: 12/04/2017] [Indexed: 11/24/2022] Open
Abstract
Aim: To investigate the feasibility of low-concentration contrast (270 mg/ml) together with low tube voltage (80 kV) and adaptive iterative dose reduction (AIDR)-3D reconstruction in liver computed tomography (CT) perfusion imaging. Method: A total of 15 healthy New Zealand rabbits received two CT scans each. The first scan (control) was acquired at 100 kV and 100 mA with iopromide (370 mg/ml), while the second scan (experimental) was acquired at 80 kV and 100 mA with iodixanol (270 mg/ml) 24 h after the first scan. The obtained images were reconstructed with filtered back projection (FBP) and AIDR-3D in the control and experimental groups respectively. The perfusion parameters (hepatic artery perfusion [HAP], portal vein perfusion [PVP], hepatic perfusion index [HPI], and total liver perfusion [TLP]) and image quality (image quality score, average CT value of abdomen aorta, signal-to-noise ratio [SNR], contrast-to-noise ratio [CNR], and figure of merit [FOM]) were compared using a paired t-test or Mann–Whitney U test between the two groups, when appropriate. The effective radiation dose and iodine intake were also recorded and compared. Results: With the exception of the FOM criteria, the image quality and perfusion parameters were not significantly different between the two groups. The effective radiation dose and iodine intake were 38.79% and 27.03% lower respectively, in the experimental group. Conclusion: Low-concentration contrast (iodixanol, 270 mg/ml) together with low tube voltage (80 kV) and AIDR-3D reconstruction help to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.
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