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Varughese NA, Panakkal NC, Nair VT, Kadavigere R, Lakshmi V, Sukumar S. Effect of patient characteristics on aortic attenuation in iodinated contrast-enhanced Abdominopelvic CT: A retrospective study. Radiography (Lond) 2024; 30 Suppl 1:94-101. [PMID: 39106556 DOI: 10.1016/j.radi.2024.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2024] [Revised: 07/19/2024] [Accepted: 07/22/2024] [Indexed: 08/09/2024]
Abstract
INTRODUCTION Contrast Enhanced Computed Tomography (CECT) abdomen and pelvis is a common imaging procedure. Hospitals typically follow fixed protocols of contrast volume administration for triple-phase CECT abdomen and pelvis scans and have found that patients are either underdosed or overdosed with respect to their body habitus. The aim of the study was to correlate different patient characteristics such as Total body weight (TBW), Lean Body Mass (LBM), Body Mass Index (BMI), Body Surface Area (BSA) and Blood Volume (BV) with aortic enhancement in the arterial and portal venous phases for CECT Abdomen and pelvis. METHODS A total of 106 patients who underwent triple-phase CECT abdomen & pelvis were retrospectively studied. A circular region-of-interest (ROI) of 100 mm2 was positioned on descending aorta for unenhanced, arterial, and portal venous phases to measure the aortic enhancement in Hounsfield's units. Measure of contrast attenuation (ΔH) was calculated from the difference of CT values on unenhanced images and contrast images. Correlation analysis was performed to evaluate the relation of patient body characteristics with aortic enhancement. RESULTS Correlation analysis revealed that BMI exhibited the least correlation when compared to the other characteristics in both arterial (r = -0.3; p = 0.002) and portovenous phases (r = -0.35; p < 0.001) whereas TBW, LBW, BSA and BV reported moderate inverse correlations. BV was found to be the strongest of all characteristics under linear regression. CONCLUSION The study supports the use of protocols that adjust contrast volume to either TBW, LBW, BSA, or BV for CT abdomen and pelvis scan. IMPLICATION OF PRACTICE The right body parameter ensures optimal contrast enhancement, improving the visualization of anatomical structures and helps in adapting tailored contrast injection protocols.
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Affiliation(s)
- N A Varughese
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - N C Panakkal
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - V T Nair
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - R Kadavigere
- Radio-diagnosis & Imaging, Department of Radio Diagnosis & Imaging, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - V Lakshmi
- Department of Data Sciences, Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.
| | - S Sukumar
- Department of Medical Imaging Technology, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India.
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Narita M, Nishiki M. [Noise Nonuniformity Dependency on Exposure Settings in Computed Tomography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2024; 80:530-538. [PMID: 38494722 DOI: 10.6009/jjrt.2024-1417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
PURPOSE In X-ray computed tomography (CT), noise distribution within images is nonuniform and thought to vary with imaging conditions. This study aimed to evaluate noise nonuniformity by altering specific imaging conditions, such as tube voltage, bow-tie filter (BTF), and phantom size. METHODS Using four tube voltages (80, 100, 120, and 135 kV), two BTF types (L and M), and circular water phantoms with diameters of 240, 320, and 400 mm, we employed filtered back projection (FBP) for reconstruction. Noise nonuniformity was assessed by defining six regions of interest (ROI) from the image center to the periphery, and the noise nonuniformity index (NNI) was calculated based on the standard deviation (SD) values within these ROIs. RESULTS Results showed consistently larger noise SD values in the central region compared to the peripheral region under all imaging conditions, with the maximum NNI reaching 32.1%. Variations in NNI were observed, reaching up to 5.5 points for tube voltage, 7.8 points for BTF, and 8.2 points for phantom size. CONCLUSION In conclusion, our quantitative assessment revealed moderate dependence of noise nonuniformity on imaging conditions in CT images.
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Affiliation(s)
- Mitsuo Narita
- Department of Radiology, International University of Health and Welfare Hospital
| | - Masayuki Nishiki
- Department of Radiological Sciences, International University of Health and Welfare
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3
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Hoyoshi K, Ohmura T, Kayano S, Goto M, Muramatsu S, Homma N. [A Review of Current Knowledge for X-ray Energy in CT: Practical Guide for CT Technologist]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2022; 78:449-463. [PMID: 35400711 DOI: 10.6009/jjrt.2022-1238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In computed tomography (CT) systems, the optimal X-ray energy in imaging depends on the material composition and the subject size. Among the parameters related to the X-ray energy, we can arbitrarily change only the tube voltage. For years, the tube voltage has often been set at 120 kVp. However, since about 2000, there has been an increasing interest in reducing radiation dose, and it has led to the publication of various reports on low tube voltage. Furthermore, with the spread of dual-energy CT, virtual monochromatic X-ray images are widely used since the contrast can be adjusted by selecting the optional energy. Therefore, because of the renewed interest in X-ray energy in CT imaging, the issue of energy and imaging needs to be summarized. In this article, we describe the basics of physical characteristics of X-ray attenuation with materials and its influence on the process of CT imaging. Moreover, the relationship between X-ray energy and CT imaging is discussed for clinical applications.
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Affiliation(s)
- Kazutaka Hoyoshi
- Department of Radiology, Yamagata University Hospital.,Department of Radiological Imaging and Informatics, Tohoku University Graduate School of Medicine
| | - Tomomi Ohmura
- Department of Radiology and Nuclear Medicine, Akita Cerebrospinal and Cardiovascular Center
| | - Shingo Kayano
- Department of Radiological Technology, Tohoku University Hospital
| | - Mitsunori Goto
- Department of Radiological Technology, Miyagi Cancer Center (Current address: Department of Radiology, Fujita Health University Hospital)
| | | | - Noriyasu Homma
- Department of Radiological Imaging and Informatics, Tohoku University Graduate School of Medicine
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Dual-Energy Computed Tomography Imaging in Early-Stage Hepatocellular Carcinoma: A Preliminary Study. CONTRAST MEDIA & MOLECULAR IMAGING 2022; 2022:2146343. [PMID: 35069041 PMCID: PMC8752295 DOI: 10.1155/2022/2146343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/05/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022]
Abstract
Background This study aims to evaluate the application of dual-energy computed tomography (DECT) for multiparameter quantitative measurement in early-stage hepatocellular carcinoma (HCC). Methods The study retrospectively enrolled 30 patients with early-stage HCC and 43 patients with early-stage HCC who received radiofrequency ablation (RFA) and underwent abdomen enhanced CT scans in GSI mode. The GSI viewer was used for image display and data analysis. The regions of interest (ROIs) were delineated in the arterial phase and the venous phase. The optimal single energy value, CT values on different energy levels (40 keV, 70 keV, 100 keV, and 140 keV), the optimal energy level, the slope of the spectral attenuation curve, the effective atomic number (Zeff), iodine concentration (IC), water concentration (WC), normalized iodine concentration (NIC), and normalized water concentration (NWC) are measured and quantitatively analyzed. Results The CT values of early-stage HCC at different single energy levels in dual phases were significantly different, and the single energy values were negatively correlated with the CT values. In the arterial phase and the venous phase, the optimal energy values for the best contrast-to-noise ratio were (68.34 ± 3.20) keV and (70.14 ± 2.01) keV, respectively. The slope of the spectral attenuation curve showed a downward trend at 40 keV, 70 keV, 100 keV, and 140 keV, but there was no statistically significant difference (P > 0.05). Zeff was positively correlated with IC and standardized IC, but has no significant correlation with WC and NWC in dual phases. Conclusion DECT imaging contains multiparameter information and has different application values for early-stage HCC, and it is necessary to select the parameters reasonably for personalized and comprehensive evaluation.
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Nakamura Y, Higaki T, Honda Y, Tatsugami F, Tani C, Fukumoto W, Narita K, Kondo S, Akagi M, Awai K. Advanced CT techniques for assessing hepatocellular carcinoma. Radiol Med 2021; 126:925-935. [PMID: 33954894 DOI: 10.1007/s11547-021-01366-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma (HCC) is the sixth-most common cancer in the world, and hepatic dynamic CT studies are routinely performed for its evaluation. Ongoing studies are examining advanced imaging techniques that may yield better findings than are obtained with conventional hepatic dynamic CT scanning. Dual-energy CT-, perfusion CT-, and artificial intelligence-based methods can be used for the precise characterization of liver tumors, the quantification of treatment responses, and for predicting the overall survival rate of patients. In this review, the advantages and disadvantages of conventional hepatic dynamic CT imaging are reviewed and the general principles of dual-energy- and perfusion CT, and the clinical applications and limitations of these technologies are discussed with respect to HCC. Finally, we address the utility of artificial intelligence-based methods for diagnosing HCC.
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Affiliation(s)
- Yuko Nakamura
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
| | - Toru Higaki
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Yukiko Honda
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Fuminari Tatsugami
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Chihiro Tani
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Wataru Fukumoto
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Keigo Narita
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Shota Kondo
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Motonori Akagi
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Kazuo Awai
- Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
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Thiravit S, Brunnquell C, Cai LM, Flemon M, Mileto A. Use of dual-energy CT for renal mass assessment. Eur Radiol 2020; 31:3721-3733. [PMID: 33210200 DOI: 10.1007/s00330-020-07426-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/11/2020] [Accepted: 10/14/2020] [Indexed: 12/22/2022]
Abstract
Although dual-energy CT (DECT) may prove useful in a variety of abdominal imaging tasks, renal mass evaluation represents the area where this technology can be most impactful in abdominal imaging compared to routinely performed contrast-enhanced-only single-energy CT exams. DECT post-processing techniques, such as creation of virtual unenhanced and iodine density images, can help in the characterization of incidentally discovered renal masses that would otherwise remain indeterminate based on post-contrast imaging only. The purpose of this article is to review the use of DECT for renal mass assessment, including its benefits and existing limitations. KEY POINTS: • If DECT is selected as the scanning mode for most common abdominal protocols, many incidentally found renal masses can be fully triaged within the same exam. • Virtual unenhanced and iodine density DECT images can provide additional information when renal masses are discovered in the post-contrast-only setting. • For renal mass evaluation, virtual unenhanced and iodine density DECT images should be interpreted side-by-side to troubleshoot pitfalls that can potentially lead to erroneous interpretation.
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Affiliation(s)
- Shanigarn Thiravit
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA.,Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Christina Brunnquell
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA
| | - Larry M Cai
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA
| | - Mena Flemon
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA
| | - Achille Mileto
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357115, Seattle, WA, 98195, USA.
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7
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Huang WH, Jhan KJ, Yang CC. Investigating the feasibility of generating dual-energy CT from one 120-kVp CT scan: a phantom study. J Appl Clin Med Phys 2020; 22:126-137. [PMID: 33426800 PMCID: PMC7882117 DOI: 10.1002/acm2.13148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/30/2020] [Accepted: 12/08/2020] [Indexed: 11/17/2022] Open
Abstract
Introduction This study aimed to investigate the feasibility of generating pseudo dual‐energy CT (DECT) from one 120‐kVp CT by using convolutional neural network (CNN) to derive additional information for quantitative image analysis through phantom study. Methods Dual‐energy scans (80/140 kVp) and single‐energy scans (120 kVp) were performed for five calibration phantoms and two evaluation phantoms on a dual‐source DECT scanner. The calibration phantoms were used to generate training dataset for CNN optimization, while the evaluation phantoms were used to generate testing dataset. A CNN model which takes 120‐kVp images as input and creates 80/140‐kVp images as output was built, trained, and tested by using Caffe CNN platform. An in‐house software to quantify contrast enhancement and synthesize virtual monochromatic CT (VMCT) for CNN‐generated pseudo DECT was implemented and evaluated. Results The CT numbers in 80‐kVp pseudo images generated by CNN are differed from the truth by 11.57, 16.67, 13.92, 12.23, 10.69 HU for syringes filled with iodine concentration of 2.19, 4.38, 8.75, 17.5, 35 mg/ml, respectively. The corresponding results for 140‐kVp CT are 3.09, 9.10, 7.08, 9.81, 7.59 HU. The estimates of iodine concentration calculated based on the proposed method are differed from the truth by 0.104, 0.603, 0.478, 0.698, 0.795 mg/ml for syringes filled with iodine concentration of 2.19, 4.38, 8.75, 17.5, 35 mg/ml, respectively. With regards to image quality enhancement, VMCT synthesized by using pseudo DECT shows the best contrast‐to‐noise ratio at 40 keV. Conclusion In conclusion, the proposed method should be a practicable strategy for iodine quantification in contrast enhanced 120‐kVp CT without using specific scanner or scanning procedure.
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Affiliation(s)
- Wen-Hui Huang
- Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan.,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Kai-Jie Jhan
- Department of Nuclear Medicine, National Taiwan University Cancer Center, Taipei, Taiwan
| | - Ching-Ching Yang
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Medical Research, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung, Taiwan
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8
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Crawford MA, Criqui MH, Forbang N, Unkart JT, Allison MA, Larsen BA. Associations of abdominal muscle area and density with coronary artery calcium volume and density: The multi-ethnic study of atherosclerosis. Metabolism 2020; 107:154230. [PMID: 32298722 PMCID: PMC7986552 DOI: 10.1016/j.metabol.2020.154230] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/23/2020] [Accepted: 04/11/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND Due to the opposing cardiovascular risk profiles of CAC volume and density, we tested the hypothesis that increased abdominal muscle area (AMA) and density (AMD) were significantly associated with lower coronary arterial calcium (CAC) volume and higher CAC density. METHODS Using data from 787 participants from the Multi-Ethnic Study of Atherosclerosis, Ancillary Body Composition Study, we analyzed abdominal and chest computed tomography (CT) scans. Abdominal scans were scored for muscle area, muscle density (attenuation) and visceral and subcutaneous fat. Chest scans were scored for CAC volume and Agatston values, which were used to derive CAC density scores. RESULTS The mean (SD) age and BMI of the participants was 67.8 (9.0) years and 27.9 (4.8) kg/m2, respectively. Forty-one percent were female, 46% were Caucasian, 60% had hypertension, 17% had diabetes, and 46% had dyslipidemia. AMA was positively associated with CAC volume (p < .001) and inversely associated with CAC density (p < .001). Conversely, AMD was inversely associated with CAC volume and positively associated with CAC density in minimally adjusted models (p < .001), but not significant in confounder adjusted models. CONCLUSION AMA and AMD had differing associations with CAC volume and density, with AMA significantly associated with a higher risk CAC profile (high volume, low density) and AMD not significantly associated with CAC volume or density. Future research needs to account for the unique components of both muscle composition and CAC.
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Affiliation(s)
- Margaret A Crawford
- University of California, San Diego/San Diego State University Joint Doctoral Program in Public Health, 9500 Gilman Dr., La Jolla, CA 92093-0965, United States of America
| | - Michael H Criqui
- Department of Family Medicine and Public Health, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0965, United States of America
| | - Nketi Forbang
- Department of Family Medicine and Public Health, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0965, United States of America
| | - Jonathan T Unkart
- Department of Family Medicine and Public Health, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0965, United States of America
| | - Matthew A Allison
- Department of Family Medicine and Public Health, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0965, United States of America
| | - Britta A Larsen
- Department of Family Medicine and Public Health, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0965, United States of America.
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Contrast Material Injection Protocol With the Dose Determined According to Lean Body Weight at Hepatic Dynamic Computed Tomography: Comparison Among Patients With Different Body Mass Indices. J Comput Assist Tomogr 2019; 43:736-740. [PMID: 31609293 DOI: 10.1097/rct.0000000000000909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of this study was to compare enhancement of the aorta and liver on hepatic dynamic computed tomography scans acquired with contrast material doses based on the lean body weight (LBW) or the total body weight (TBW). METHODS We randomly divided 529 patients (279 men, 250 women; median age, 66 years) scheduled for hepatic dynamic computed tomography into 2 groups. The LBW patients (n = 278) were injected with 679 mg iodine/kg (men) or 762 mg iodine/kg (women). The TBW group (n = 251) was injected with 600 mg iodine/kg TBW. Each group was subdivided into the 3 classes based on the body mass index (BMI; low, normal, high). Aortic enhancement during the hepatic arterial phase and hepatic enhancement during the portal venous phase was compared. The aortic and hepatic equivalence margins were 100 and 20 Hounsfield units, respectively. RESULTS Comparison of the median iodine dose in patients with a normal or high BMI showed that it was significantly lower under the LBW protocol than the TBW protocol (558.2 and 507.0 mg iodine/kg, P < 0.001, respectively). However, in patients with a low BMI, the LBW protocol delivered a significantly higher dose than the TBW protocol (620.7 vs 600.0 mg iodine/kg, P < 0.001). The 95% confidence interval for the difference in aortic and hepatic enhancement between the 2 protocols was within the range of the predetermined equivalence margins in all BMI subgroups. CONCLUSIONS Contrast enhancement was equivalent under both protocols. The LBW protocol can avoid iodine overdosing, especially in patients with a high BMI.
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Baliyan V, Shaqdan K, Hedgire S, Ghoshhajra B. Vascular computed tomography angiography technique and indications. Cardiovasc Diagn Ther 2019; 9:S14-S27. [PMID: 31559151 DOI: 10.21037/cdt.2019.07.04] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Non-invasive cross-sectional imaging techniques play a crucial role in the assessment of the vascular disease processes. Computed tomography angiography (CTA) is an imaging method of choice for a wide range of vascular diseases that span across different vascular territories. A diagnostic quality CTA requires a robust imaging protocol tailored according to the physiologic state and vascular area of interest. This review article is aimed to provide an overview of the technical considerations and clinical applications of CTA.
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Affiliation(s)
- Vinit Baliyan
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Khalid Shaqdan
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Sandeep Hedgire
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Brian Ghoshhajra
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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11
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Optimizing Pulmonary Embolism Computed Tomography in the Age of Individualized Medicine: A Prospective Clinical Study. Invest Radiol 2019; 53:306-312. [PMID: 29438139 DOI: 10.1097/rli.0000000000000443] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE The aim of the study was to simultaneously optimize contrast media (CM) injection and scan parameters for the individual patient during computed tomography pulmonary angiography (CTPA). METHODS In this study (NCT02611115), 235 consecutive patients suspected of having pulmonary embolism were prospectively enrolled. Automated kV selection software on a third-generation multidetector computed tomography adapted tube voltage to the individual patient, based on scout scans. The contrast injection protocol was adapted to both patient body weight and kV-setting selection via a predefined formula, based on previous research. Injection data were collected from a contrast media and radiation dose monitoring software. Attenuation was measured in Hounsfield units (HU) in the pulmonary trunk (PT); attenuation values 200 HU or greater were considered diagnostic. Subjective image quality was assessed by using a 4-point Likert scale at the level of the PT, lobar, segmental, and subsegmental arteries. Results between groups were reported as mean ± SD. RESULTS Two hundred twenty-two patients (94%) were scanned at a kV setting below 100 kV: n = 108 for 70 kV, n = 82 for 80 kV, and n = 32 for 90 kV. Mean CM bolus volume (in milliliters) and total iodine load (in grams of iodine) for 70 to 90 kV were as follows: 24 ± 3 mL and 7 ± 1 g I, 29 ± 4 mL and 9 ± 2 g I, and 38 ± 4 mL and 11 ± 1 g I, respectively. Mean flow rates (in milliliters per second) and iodine delivery rates (in grams of iodine per second) were 3.0 ± 0.4 mL/s and 0.9 ± 0.1 g I/s (70 kV), 3.6 ± 0.4 mL/s and 1.0 ± 0.1 g I/s (80 kV), and 4.7 ± 0.5 mL/s and 1.3 ± 0.1 g I/s (90 kV). Mean radiation doses were 1.3 ± 0.3 mSv at 70 kV, 1.7 ± 0.4 mSv at 80 kV, and 2.2 ± 0.6 mSv at 90 kV. Mean vascular attenuation in the PT for each kV group was as follows: 397 ± 101 HU for 70 kV, 398 ± 96 HU for 80 kV, and 378 ± 100 HU for 90 kV, P = 0.59. Forty-six patients (21%) showed pulmonary embolism on the CTPA. One scan (90 kV) showed nondiagnostic segmental pulmonary arteries, and 5% of subsegmental arteries were of nondiagnostic image quality. All other segments were considered diagnostic-excellent subjective image quality. CONCLUSIONS Simultaneously optimizing both CM injections and kV settings to the individual patient in CTPA results in diagnostic attenuation with on average 24 to 38 mL of CM volume and a low radiation dose for most patients. This individualized protocol may help overcome attenuation-variation problems between patients and kV settings in CTPA.
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12
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Role of dual energy CT to improve diagnosis of non-traumatic abdominal vascular emergencies. Abdom Radiol (NY) 2019; 44:406-421. [PMID: 30143817 DOI: 10.1007/s00261-018-1741-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Computed tomography angiography (CTA) is the modality of choice to evaluate abdominal vascular emergencies (AVE). CTA protocols are often complex and require acquisition of multiple phases to enable a variety of diagnosis such as acute bleeding, pseudoaneurysms, bowel ischemia, and dissection. With single energy CT (SECT), differentiating between calcium, coagulated blood, and contrast agents can be challenging based on their attenuation, especially when in small quantity or present as a mixture. With dual-energy CT (DECT), virtual monoenergetic (VM) and material decomposition (MD) image reconstructions enable more robust tissue characterization, improve contrast-enhancement, and reduce beam hardening artifacts. This article will demonstrate how radiologists can utilize DECT for various clinical scenarios in assessment of non-traumatic AVE.
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13
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Abazid RM, Smettei OA, Almeman A, Sayed S, Alsaqqa H, Abdelmageed SM, Alharbi FJ, Alhabib AM, Al-Mallah MH. Fat volume measurements as a predictor of image noise in coronary computed tomography angiography. J Saudi Heart Assoc 2018; 31:32-40. [PMID: 30559578 PMCID: PMC6289940 DOI: 10.1016/j.jsha.2018.11.001] [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: 03/07/2018] [Revised: 08/19/2018] [Accepted: 11/12/2018] [Indexed: 11/16/2022] Open
Abstract
Introduction Image noise can negatively affect the overall quality of coronary computed tomography angiography (CCTA). Objectives The purpose of this study was to evaluate the relationship between image noise and fat volumes in the chest wall. We also aimed to compare these with other patient-specific predictors of image noise, such as body weight (BW) and body mass index (BMI). Methods We undertook a cross-sectional, single-center study. A tube voltage of 100 kV was used for patients with BW <85 kg and 120 kV for BW ≥85 kg. The image noise in the aortic root, single-slice fat volume (SFV) at the level of the left main coronary artery and the total fat volume of the chest (TFV) were analyzed. Results A total of 132 consecutive patients were enrolled (mean age ± standard deviation, 51 ± 11 years; 64% male). The mean image noise was 30.5 ± 11 Hounsfield units (HU). We found that patients with image noise >30 HU had significantly higher SFV (75 ± 33 vs. 51 ± 24, p < 0.0001) and TFV (2206 ± 927 vs. 1815 ± 737, p < 0.01) compared with patients having noise ≤30 HU, whereas BW and BMI showed no significant difference (78 ± 13 vs. 81 ± 14, p < 0.34) and (28.7 ± 4.7 vs. 26.8 ± 3.8, p < 0.19), respectively. Linear regression analysis showed that image noise has better correlation with SFV (R = 0.399; p < 0.0001); and TFV (R = 0, p < 0.009) than BMI (R = 0.154, p < 0.039) and BW (R = -0.102, p = 0.12). Conclusions Fat volume measurements of the chest wall can predict CCTA image noise better than other patient-specific predictors, such as BW and BMI.
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Affiliation(s)
- Rami M. Abazid
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
- Corresponding author at: Department of Cardiology, Prince Sultan Cardiac Center–Qassim (PSCCQ), Postal Code 2290, Buraydah, Al-Qassim, Saudi Arabia.
| | - Osama A. Smettei
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
| | - Ahmad Almeman
- Department of pharmacology, Qassim University, Qassim, Buraydah, Saudi Arabia
| | - Sawsan Sayed
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
| | - Hanaa Alsaqqa
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
| | - Salma M. Abdelmageed
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
| | - Fahad J. Alharbi
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
| | - Abdullah M. Alhabib
- Department of Cardiology, Cardiac Imaging, Prince Sultan Cardiac Center–Qassim PSCCQ, King Fahad Specialist Hospital, Buraydah, Saudi Arabia
| | - Mouaz H. Al-Mallah
- Department of Medicine, Wayne State University, Detroit, MI, USA
- Cardiac Imaging, King Abdul-Aziz Cardiac Center, National Guard Health Affairs, Riyadh, Saudi Arabia
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Lambert JW, Sun Y, Stillson C, Li Z, Kumar R, Wang S, FitzGerald PF, Bonitatibus PJ, Colborn RE, Roberts JC, Edic PM, Marino M, Yeh BM. An Intravascular Tantalum Oxide-based CT Contrast Agent: Preclinical Evaluation Emulating Overweight and Obese Patient Size. Radiology 2018; 289:103-110. [PMID: 29969071 DOI: 10.1148/radiol.2018172381] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Purpose To compare the CT imaging performance of a carboxybetaine zwitterionic-coated tantalum oxide (TaCZ) nanoparticle CT contrast agent with that of a conventional iodinated contrast agent in a swine model meant to simulate overweight and obese patients. Materials and Methods Four swine were evaluated inside three different-sized adipose-equivalent encasements emulating abdominal girths of 102, 119, and 137 cm. Imaging was performed with a 64-detector row CT scanner at six scan delays after intravenous injection of 240 mg element (Ta or I) per kilogram of body weight of TaCZ or iopromide. For each time point, contrast enhancement of the aorta and liver were measured by using regions of interest. Two readers independently recorded the clarity of vasculature using a five-point Likert scale. Findings were compared by using paired t tests and Wilcoxon signed-rank tests. Results Mean peak enhancement was higher for TaCZ than for iopromide in the aorta (270 HU [σ = 24.5] vs 199 HU [σ = 10.2], P < .001) and liver (61.3 HU [σ = 11.7] vs 45.2 HU [σ = 8], P < .001). Vascular clarity was higher for TaCZ than for iopromide in 63% (132 of 208), 82% (170 of 208), and 86% (178 of 208) of the individual vessels at the 102-, 119-, and 137-cm girths, respectively (P < .01). Arterial clarity scores were higher for TaCZ than for iopromide in 62% (208 of 336) of vessels. Venous clarity scores were higher for TaCZ than for iopromide in 89% (128 of 144) of the veins in the venous phase and in 100% (144 of 144) of veins in the delayed phase (P < .01). No vessel showed higher clarity score with iopromide than with TaCZ. Conclusion An experimental tantalum nanoparticle-based contrast agent showed greater contrast enhancement compared with iopromide in swine models meant to simulate overweight and obese patients. © RSNA, 2018.
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Affiliation(s)
- Jack W Lambert
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Yuxin Sun
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Carol Stillson
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Zhixi Li
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Rahi Kumar
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Sizhe Wang
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Paul F FitzGerald
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Peter J Bonitatibus
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Robert E Colborn
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Jeannette C Roberts
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Peter M Edic
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Michael Marino
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
| | - Benjamin M Yeh
- From the Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628 (J.W.L., Y.S., C.S., Z.L., R.K., S.W., B.M.Y.); and Departments of Imaging (P.F.F., P.M.E.) and Biosciences (P.J.B., R.E.C., J.C.R., M.M.), GE Global Research, Niskayuna, NY
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15
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Ohira S, Karino T, Ueda Y, Nitta Y, Kanayama N, Miyazaki M, Koizumi M, Teshima T. How Well Does Dual-energy CT with Fast Kilovoltage Switching Quantify CT Number and Iodine and Calcium Concentrations? Acad Radiol 2018; 25:519-528. [PMID: 29275940 DOI: 10.1016/j.acra.2017.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/19/2017] [Accepted: 11/04/2017] [Indexed: 01/13/2023]
Abstract
RATIONALE AND OBJECTIVES Because it is imperative for understanding the performance of dual-energy computed tomography scanner to determine clinical diagnosis, we aimed to assess the accuracy of quantitative measurements using dual-energy computed tomography with fast kilovoltage switching. MATERIALS AND METHODS Quantitative measurements were performed for 16 reference materials (physical density, 0.965-1.550 g/cm3; diameter of rod, 2.0-28.5 mm; iodine concentration, 2-15 mg/mL; and calcium concentration, 50-300 mg/mL) with varying scanning settings, and the measured values were compared to their theoretical values. RESULTS For high-density material, the maximum differences in Hounsfield unit values in the virtual monochromatic images at 50, 70, and 100 keV were -176.2, 61.0, and -35.2 HU, respectively, and the standard deviations over short- and long-term periods were 11.1, 6.1, and 3.5 HU at maximum. The accuracy of the Hounsfield unit measurement at 50 and 70 keV was significantly higher (P < 0.05) with higher radiation output and smaller phantom size. The difference in the iodine and calcium measurements in the large phantom were up to -2.6 and -60.4 mg/mL for iodine (5 mg/mL with 2-mm diameter) and calcium (300 mg/mL) materials, and the difference was improved with a small phantom. Metal artifact reduction software improved subjective image quality; however, the quantitative values were significantly underestimated (P < 0.05) (-49.5, -26.9, and -15.3 HU for 50, 70, and 100 keV, respectively; -1.0 and -17 mg/mL for iodine and calcium concentration, respectively) compared to that acquired without a metal material. CONCLUSIONS The accuracy of quantitative measurements can be affected by material density and the size of the object, radiation output, phantom size, and the presence of metal materials.
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16
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Muroga K, Fukuzawa A, Tsukioka H, Akizawa Y, Ichikawa K. [Effect of Tube Voltage on Contrast Enhancement and Contrast Medium Dose in Abdominal Contrast-enhanced Computed Tomography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2018; 74:61-67. [PMID: 29353837 DOI: 10.6009/jjrt.2018_jsrt_74.1.61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The purpose of this study was to investigate the effect of tube voltage on relationship between a patient's body weight and contrast enhancement in abdominal contrast-enhanced computed tomography (CT). Five phantoms with diameters ranging from 19.2 to 30.6 cm, including syringes filled with iodine solution diluted to different concentrations, were used to compare the effects at tube voltages of 80, 100, and 120 kVp. Furthermore, for clinical study, 300 patients who underwent abdominal contrast-enhanced CT examinations were enrolled and enhancements of aorta and hepatic parenchyma in arterial phase and equilibrium phase were compared at 80, 100, and 120 kVp using a contrast medium administration proportional to the body weight. The contrast enhancement was decreased with increase in phantom size because of the beam-hardening effect, and however, the decrease was less at low tube voltages of 80 and 100 kVp (lowest at 80 kVp), demonstrating the beam-hardening effect was reduced at low tube voltages. The enhancements of aorta and hepatic parenchyma indicated tended to increase in patients with a heavy body weight, and this trend was stronger at 80 and 100 kVp (80 kVp>100 kVp). Therefore, it was indicated that the problem of excessive contrast enhancement in patients with a high body weight was prominent at low tube voltages because the beam-hardening effect in patients with a heavy body weight was weaken by low tube voltages.
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Affiliation(s)
- Koji Muroga
- Department of Diagnostic Radiology, Nagano Red Cross Hospital.,Graduate School of Medical Science, Kanazawa University
| | - Akira Fukuzawa
- Department of Diagnostic Radiology, Nagano Red Cross Hospital
| | | | - Yuka Akizawa
- Department of Diagnostic Radiology, Nagano Red Cross Hospital
| | - Katsuhiro Ichikawa
- Institute of Medical, Pharmaceutical and Health Science, Kanazawa University
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17
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The Effect of Patient Diameter on the Dual-Energy Ratio of Selected Contrast-Producing Elements. J Comput Assist Tomogr 2017; 41:505-510. [PMID: 27824676 DOI: 10.1097/rct.0000000000000557] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVES The aim of this study was to assess whether the low- to high-kVp computed tomography (CT) number ratio at dual-energy CT is affected by changes in patient diameter. METHODS Seven contrast-producing elements were housed sequentially within an abdomen phantom. Fat rings enlarged the phantom diameter from 26 to 44 cm. The phantom was scanned using single-energy CT at tube potentials of 80 and 140 kVp and rapid-kVp-switching dual-energy CT. RESULTS CT numbers decreased proportionally (∼20% CT number reduction for smallest to largest phantom diameters) for low- and high-energy acquisitions but resulted in consistent dual-energy ratios for each contrast element. For 17 of 21 material pair combinations, the dual-energy ratio ranges of the two elements did not overlap, implying that discrimination should remain possible for these material pairs at all patient sizes. CONCLUSIONS The dual-energy ratio for different contrast materials is largely unaffected by changes in phantom diameter. This should allow for robust separation of most contrast material combinations irrespective of patient size.
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18
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Yeh BM, FitzGerald PF, Edic PM, Lambert JW, Colborn RE, Marino ME, Evans PM, Roberts JC, Wang ZJ, Wong MJ, Bonitatibus PJ. Opportunities for new CT contrast agents to maximize the diagnostic potential of emerging spectral CT technologies. Adv Drug Deliv Rev 2017; 113:201-222. [PMID: 27620496 PMCID: PMC5344792 DOI: 10.1016/j.addr.2016.09.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 12/15/2022]
Abstract
The introduction of spectral CT imaging in the form of fast clinical dual-energy CT enabled contrast material to be differentiated from other radiodense materials, improved lesion detection in contrast-enhanced scans, and changed the way that existing iodine and barium contrast materials are used in clinical practice. More profoundly, spectral CT can differentiate between individual contrast materials that have different reporter elements such that high-resolution CT imaging of multiple contrast agents can be obtained in a single pass of the CT scanner. These spectral CT capabilities would be even more impactful with the development of contrast materials designed to complement the existing clinical iodine- and barium-based agents. New biocompatible high-atomic number contrast materials with different biodistribution and X-ray attenuation properties than existing agents will expand the diagnostic power of spectral CT imaging without penalties in radiation dose or scan time.
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Affiliation(s)
- Benjamin M Yeh
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628, United States.
| | - Paul F FitzGerald
- General Electric Global Research, One Research Circle, Niskayuna, NY 12309, United States
| | - Peter M Edic
- General Electric Global Research, One Research Circle, Niskayuna, NY 12309, United States
| | - Jack W Lambert
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628, United States
| | - Robert E Colborn
- General Electric Global Research, One Research Circle, Niskayuna, NY 12309, United States
| | - Michael E Marino
- General Electric Global Research, One Research Circle, Niskayuna, NY 12309, United States
| | - Paul M Evans
- GE Healthcare Life Sciences, The Grove Centre, White Lion Road, Amersham, Buckinghamshire HP7 9LL, United Kingdom
| | - Jeannette C Roberts
- General Electric Global Research, One Research Circle, Niskayuna, NY 12309, United States
| | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628, United States
| | - Margaret J Wong
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143-0628, United States
| | - Peter J Bonitatibus
- General Electric Global Research, One Research Circle, Niskayuna, NY 12309, United States
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Higashigaito K, Schmid T, Puippe G, Morsbach F, Lachat M, Seifert B, Pfammatter T, Alkadhi H, Husarik DB. CT Angiography of the Aorta: Prospective Evaluation of Individualized Low-Volume Contrast Media Protocols. Radiology 2016; 280:960-8. [DOI: 10.1148/radiol.2016151982] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Park YK, Sharp GC, Phillips J, Winey BA. Proton dose calculation on scatter-corrected CBCT image: Feasibility study for adaptive proton therapy. Med Phys 2016; 42:4449-59. [PMID: 26233175 DOI: 10.1118/1.4923179] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To demonstrate the feasibility of proton dose calculation on scatter-corrected cone-beam computed tomographic (CBCT) images for the purpose of adaptive proton therapy. METHODS CBCT projection images were acquired from anthropomorphic phantoms and a prostate patient using an on-board imaging system of an Elekta infinity linear accelerator. Two previously introduced techniques were used to correct the scattered x-rays in the raw projection images: uniform scatter correction (CBCTus) and a priori CT-based scatter correction (CBCTap). CBCT images were reconstructed using a standard FDK algorithm and GPU-based reconstruction toolkit. Soft tissue ROI-based HU shifting was used to improve HU accuracy of the uncorrected CBCT images and CBCTus, while no HU change was applied to the CBCTap. The degree of equivalence of the corrected CBCT images with respect to the reference CT image (CTref) was evaluated by using angular profiles of water equivalent path length (WEPL) and passively scattered proton treatment plans. The CBCTap was further evaluated in more realistic scenarios such as rectal filling and weight loss to assess the effect of mismatched prior information on the corrected images. RESULTS The uncorrected CBCT and CBCTus images demonstrated substantial WEPL discrepancies (7.3 ± 5.3 mm and 11.1 ± 6.6 mm, respectively) with respect to the CTref, while the CBCTap images showed substantially reduced WEPL errors (2.4 ± 2.0 mm). Similarly, the CBCTap-based treatment plans demonstrated a high pass rate (96.0% ± 2.5% in 2 mm/2% criteria) in a 3D gamma analysis. CONCLUSIONS A priori CT-based scatter correction technique was shown to be promising for adaptive proton therapy, as it achieved equivalent proton dose distributions and water equivalent path lengths compared to those of a reference CT in a selection of anthropomorphic phantoms.
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Affiliation(s)
- Yang-Kyun Park
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Gregory C Sharp
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Justin Phillips
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Brian A Winey
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
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Bucher AM, Wichmann JL, Schoepf UJ, Wolla CD, Canstein C, McQuiston AD, Krazinski AW, De Cecco CN, Meinel FG, Vogl TJ, Geyer LL. Quantitative evaluation of beam-hardening artefact correction in dual-energy CT myocardial perfusion imaging. Eur Radiol 2015; 26:3215-22. [DOI: 10.1007/s00330-015-4137-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/23/2015] [Indexed: 10/22/2022]
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Dual-Energy MDCT in Hypervascular Liver Tumors: Effect of Body Size on Selection of the Optimal Monochromatic Energy Level. AJR Am J Roentgenol 2014; 203:1257-64. [DOI: 10.2214/ajr.13.12229] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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23
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Megyeri B, Christe A, Schindera ST, Horkay E, Sikula J, Cullmann JL, Kollar J, Heverhagen JT, Szucs-Farkas Z. Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients. Clin Radiol 2014; 70:54-61. [PMID: 25459197 DOI: 10.1016/j.crad.2014.09.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 09/13/2014] [Accepted: 09/17/2014] [Indexed: 11/15/2022]
Abstract
AIM To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.
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Affiliation(s)
- B Megyeri
- Department of Anaesthesiology and Intensive Care, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - A Christe
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland
| | - S T Schindera
- Department of Radiology, University Hospital Basel, Petersgraben 4, Basel, CH-4031, Switzerland
| | - E Horkay
- Department of Radiology, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - J Sikula
- Department of Radiology, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - J L Cullmann
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland
| | - J Kollar
- Department of Radiology, University of Debrecen, Clinical Centre, Nagyerdei krt. 98, Debrecen, H-4012, Hungary
| | - J T Heverhagen
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland
| | - Z Szucs-Farkas
- University Institute of Diagnostic, Interventional and Paediatric Radiology, Inselspital, University Hospital Bern, Freiburgstrasse 10, Berne, CH-3010, Switzerland; Institute of Radiology, Hospital Centre of Biel, Vogelsang 84, Biel/Bienne, CH-2501, Switzerland.
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Dindyal S, Rahman S, Kyriakides C. Review of the Use of Ionizing Radiation in Endovascular Aneurysm Repair. Angiology 2014; 66:607-12. [PMID: 25225195 DOI: 10.1177/0003319714548564] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Endovascular repair for aortic aneurysm (EVAR) is rapidly increasing in popularity. The nature of this intervention requires significant exposure to ionizing radiation both during the procedure and for postoperative surveillance, generally in the form of computed tomography. Here the authors review the literature for radiation exposure during EVAR, both for the patient and the physician.
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Affiliation(s)
- S Dindyal
- Academic department of circulatory sciences, Vascular and Endovascular Surgery, Barts and The London NHS Trust, The Royal London Hospital, Whitechappel, London, United Kingdom
| | - S Rahman
- Academic department of circulatory sciences, Vascular and Endovascular Surgery, Barts and The London NHS Trust, The Royal London Hospital, Whitechappel, London, United Kingdom
| | - C Kyriakides
- Academic department of circulatory sciences, Vascular and Endovascular Surgery, Barts and The London NHS Trust, The Royal London Hospital, Whitechappel, London, United Kingdom
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Megibow AJ, Chandarana H, Hindman NM. Increasing the Precision of CT Measurements with Dual-Energy Scanning. Radiology 2014; 272:618-21. [DOI: 10.1148/radiol.14141118] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Marin D, Fananapazir G, Mileto A, Choudhury KR, Wilson JM, Nelson RC. Dual-Energy Multi–Detector Row CT with Virtual Monochromatic Imaging for Improving Patient-to-Patient Uniformity of Aortic Enhancement during CT Angiography: An in Vitro and in Vivo Study. Radiology 2014; 272:895-902. [DOI: 10.1148/radiol.14132857] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Szucs-Farkas Z, Megyeri B, Christe A, Vock P, Heverhagen JT, Schindera ST. Prospective randomised comparison of diagnostic confidence and image quality with normal-dose and low-dose CT pulmonary angiography at various body weights. Eur Radiol 2014; 24:1868-77. [DOI: 10.1007/s00330-014-3208-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/14/2014] [Accepted: 04/28/2014] [Indexed: 01/23/2023]
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28
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Whole-Body CT Angiography With Low Tube Voltage and Low-Concentration Contrast Material to Reduce Radiation Dose and Iodine Load. AJR Am J Roentgenol 2014; 202:W106-16. [PMID: 24370154 DOI: 10.2214/ajr.13.10720] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Mobberley SD, Fuld MK, Sieren JP, Primak AN, Hoffman EA. Scatter correction associated with dedicated dual-source CT hardware improves accuracy of lung air measures. Acad Radiol 2013; 20:1334-43. [PMID: 24119345 DOI: 10.1016/j.acra.2013.04.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 04/09/2013] [Accepted: 04/09/2013] [Indexed: 11/17/2022]
Abstract
RATIONALE AND OBJECTIVES Accurate assessment of air density used to quantitatively characterize amount and distribution of emphysema in chronic obstructive pulmonary disease (COPD) subjects has remained challenging. Hounsfield units (HU) within tracheal air can be considerably less negative than -1000 HU. This study has sought to characterize the effects of improved scatter correction used in dual-source pulmonary computed tomography (CT). MATERIALS AND METHODS Dual-source dual-energy (DSDE) and single-source (SS) scans taken at multiple energy levels and scan settings were acquired for quantitative comparison using anesthetized ovine (n = 6), swine (n = 13), and a lung phantom. Data were evaluated for the lung, inferior vena cava, and tracheal segments. To minimize the effect of cross-scatter, the phantom scans in the DSDE mode were obtained by reducing the current of one of the tubes to near zero. RESULTS A significant shift in mean HU values in the tracheal regions of animals and the phantom is observed, with values consistently closer to -1000 HU in DSDE mode. HU values associated with SS mode demonstrated a positive shift of up to 32 HU. In vivo tracheal air measurements demonstrated considerable variability with SS scanning, whereas these values were more consistent with DSDE imaging. Scatter effects in the lung parenchyma differed from adjacent tracheal measures. CONCLUSION Data suggest that the scatter correction introduced into the dual-energy mode of imaging has served to provide more accurate CT lung density measures sought to quantitatively assess the presence and distribution of emphysema in COPD subjects. Data further suggest that CT images, acquired without adequate scatter correction, cannot be corrected by linear algorithms given the variability in tracheal air HU values and the independent scatter effects on lung parenchyma.
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Affiliation(s)
- Sean D Mobberley
- Department of Radiology, Division of Physiological Imaging, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, CC 701 GH, University of Iowa Carver College of Medicine, Iowa City, IA 52241; Department of Biomedical Engineering, University of Iowa, Iowa City, IA
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Effect of Patient Size on Mean Sterile Water Attenuation During Multiphase CT Examinations. AJR Am J Roentgenol 2013; 200:1048-53. [DOI: 10.2214/ajr.12.9198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Yamao Y, Yamakado K, Takaki H, Yamada T, Kodama H, Nagasawa N, Nakatsuka A, Uraki J, Takeda K. CT-fluoroscopy in chest interventional radiology: sliding scale of imaging parameters based on radiation exposure dose and factors increasing radiation exposure dose. Clin Radiol 2012; 68:162-6. [PMID: 22906574 DOI: 10.1016/j.crad.2012.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 05/26/2012] [Accepted: 05/29/2012] [Indexed: 11/16/2022]
Abstract
AIM To verify the usefulness of a sliding scale of imaging parameters to reduce radiation exposure during chest interventional radiology (IR), and to identify factors that increase radiation exposure in order to obtain acceptable computed tomography (CT)-fluoroscopy image quality. MATERIALS AND METHODS The institutional review board approved this retrospective study, for which the need for informed consent was waived. Interventional radiologists determined the optimal CT-fluoroscopy imaging parameters using the sliding scale based on the radiation exposure dose. The imaging parameters were changed from those generating low radiation (120 kV/10 mA, 1.2 mGy/s) to others generating higher radiation exposure until acceptable image quality was obtained for each procedure. Validation of the imaging parameter sliding scale was done using regression analysis. Factors that increase radiation exposure were identified using multiple regression analysis. RESULTS In 125 patients, 217 procedures were performed, of which 72 procedures (33.2%, 72/217) were performed with imaging parameters of minimum radiation exposure, but increased radiation exposure was necessary in 145 (66.8%, 145/217). Significant correlation was found between the radiation exposure dose and the percentage achievement of acceptable image quality (R(2) = 0.98). Multivariate regression analysis showed that high body weight (p < 0.0001), long device passage (p < 0.0001), and lesions above the aortic arch (p = 0.04) were significant independent factors increasing radiation exposure. CONCLUSION Although increased radiation exposure dose might be necessary to obtain acceptable chest CT-fluoroscopy images depending on the patient, lesion, and procedure characteristics, a sliding scale of imaging parameters helps to reduce radiation exposure.
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Affiliation(s)
- Yoshikazu Yamao
- Department of Radiology, Mie University Hospital, Tsu, Japan.
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The influence of chest wall tissue composition in determining image noise during cardiac CT. AJR Am J Roentgenol 2012; 197:1328-34. [PMID: 22109286 DOI: 10.2214/ajr.11.6816] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The purpose of this article is to determine the influence of chest wall composition on image quality in cardiac CT. MATERIALS AND METHODS A retrospective study of 100 consecutive patients referred for CT coronary artery calcium assessment was performed. Image noise (Hounsfield units) was measured by prescribing a region of interest in the descending thoracic aorta. Image noise was correlated with conventional patient biometric parameters, including body weight, body mass index (BMI), and anteroposterior and lateral thoracic diameters, and with novel patient biometric parameters, including total chest wall soft tissue, chest wall fat, and chest wall muscle and bone. The linear correlation coefficient was used to indicate the strength of the association. RESULTS A strong correlation was noted between BMI and image noise in men (r = 0.66), but the strongest relationships were observed in larger women (BMI ≥ 25), who had more chest wall fat than muscle and very strong correlations between image noise, chest wall fat (r = 0.82), and total chest wall soft tissue (r = 0.85). CONCLUSION Chest wall composition has a significant correlation with image noise for cardiac CT. Therefore, strategies that target radiation dose reduction should incorporate adaptation to chest wall composition. These determinations become more significant given the current obesity epidemic.
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Bashir MR, Weber PW, Husarik DB, Howle LE, Nelson RC. Improved aortic enhancement in CT angiography using slope-based triggering with table speed optimization: a pilot study. Int J Cardiovasc Imaging 2011; 28:1533-43. [PMID: 21898186 DOI: 10.1007/s10554-011-9945-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022]
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