1
|
Gupta A, Obmann VC, Jordan M, Lennartz S, Obmann MM, Große Hokamp N, Zopfs D, Pennig L, Fürtjes G, Ramaiya N, Gilkeson R, Laukamp KR. CT artifacts after contrast media injection in chest imaging: evaluation of post-processing algorithms, virtual monoenergetic images and their combination for artifact reduction. Quant Imaging Med Surg 2021; 11:226-239. [PMID: 33392024 DOI: 10.21037/qims-20-435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background After injection into a brachial vein, high contrast media concentration in axillary and subclavian veins can cause artifacts that impair diagnostic utility. This study assessed artifact reduction by artifact-reduction-algorithms (ARA) and virtual-monoenergetic-images (VMI), as well as their combination (VMIARA) compared to conventional CT-images (CI). Methods Forty-six spectral-detector-CT (SDCT) examinations of patients that received ARA-reconstructions due to perivenous-artifacts were included in this retrospective study. CI, ARA, VMI, and VMIARA (range: 70-200 keV) were reconstructed. Objective analysis was performed with ROI-based assessment of mean and standard deviation of attenuation (HU) in hypo- and hyperdense artifacts and impaired muscle and arteries as well as artifact-free reference-tissue. Extent of artifact reduction, assessment of surrounding soft tissue and vessels, and appearance of new artifacts were rated visually by two radiologists. Results Hypo- and hyperdense artifacts showed significant improvement as evidenced by decreasing attenuation differences between artifact impaired and artifact-free reference tissue in ARA, VMI ≥80 keV, and VMIARA between 70-200 keV (e.g., CI/ARA/VMI100keV/VMIARA100keV: hypodense artifacts, (-)264.8±150.9/(-)87.1±78.9/(-)48.6±64.6/9.9±63.9 HU; P<0.001); hyperdense artifacts, 164.2±51.1/82.1±73.2/7.9±34.7/(-)17.3±50.7 HU; P<0.001). Artifacts impairing surrounding muscle and arteries were also reduced by all three approaches. In visual assessment, ARA, VMI ≥100 keV, and VMIARA between 70-200 keV also showed significant artifact reduction and improved assessment; however, for assessment of arteries improvement was not significant using ARA alone. New artifacts were reported, particularly at higher keV-values. Conclusions In presence of perivenous-artifacts, ARA, VMI and their combination allow for significant artifact reduction; however, their combination and VMI as a standalone approach yielded best results and should therefore be used, if available.
Collapse
Affiliation(s)
- Amit Gupta
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Verena Carola Obmann
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Michelle Jordan
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Markus Michael Obmann
- Clinic of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Nils Große Hokamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Gina Fürtjes
- Center for Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Robert Gilkeson
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Kai Roman Laukamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
2
|
Laukamp KR, Lennartz S, Ho V, Große Hokamp N, Zopfs D, Gupta A, Graner FP, Borggrefe J, Gilkeson R, Ramaiya N. Evaluation of the liver with virtual non-contrast: single institution study in 149 patients undergoing TAVR planning. Br J Radiol 2020; 93:20190701. [PMID: 31825655 DOI: 10.1259/bjr.20190701] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE To evaluate accuracy of virtual-non-contrast images (VNC) compared to true-unenhanced-images (TNC) for evaluation of liver attenuation acquired using spectral-detector CT (SDCT). METHODS 149 patients who underwent multiphase transcatheter-aortic-valve-replacement (TAVR) SDCT-examinations [unenhanced-chest (TNC), CT-angiography chest (CTA-chest, early arterial-phase) and abdomen (CTA-abdomen, additional early arterial-phase after a second injection of contrast media)] were retrospectively included. VNC of CTA-chest (VNC-chest) and CTA-abdomen (VNC-abdomen) were reconstructed and compared to TNC. Region of interest-based measurement of mean attenuation (Hounsfield unit, HU) was applied in the following regions: liver, spleen, abdominal aorta and paraspinal muscle. RESULTS VNC accuracy was high in the liver, spleen, abdominal aorta and muscle for abdomen-scanning. For the liver, average attenuation was 59.0 ± 9.1 HU for TNC and 72.6 ± 9.5 HU for CTA-abdomen. Liver attenuation in VNC-abdomen (59.1 ± 6.4 HU) was not significantly different from attenuation in TNC (p > 0.05). In contrast, VNC was less accurate for chest-scanning: Due to the protocol, in CTA-chest no contrast media was present in the liver parenchyma as indicated by the same attenuation in TNC (59.0 ± 9.1 HU) and CTA-chest (58.8 ± 8.9 HU, p > 0.05). Liver attenuation in VNC-chest (56.2 ± 6.4 HU, p < 0.05) was, however, significantly lower than in TNC and CTA-chest implying an artificial reduction of attenuation. CONCLUSION VNC performed well in a large cohort of TAVR-examinations yielding equivalent mean attenuations to TNC; however, application of this technique might be limited when no or very little contrast media is present in parenchyma, more precisely in an early arterial-phase of the liver. ADVANCES IN KNOWLEDGE This study showed that VNC can be reliably applied in cardiac protocols when certain limitations are considered.
Collapse
Affiliation(s)
- Kai Roman Laukamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Vivian Ho
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Nils Große Hokamp
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA.,Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Amit Gupta
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Frank Philipp Graner
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Jan Borggrefe
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Robert Gilkeson
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| | - Nikhil Ramaiya
- Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
| |
Collapse
|
3
|
Yu Y, Yin W, Liao K, Liu T, Wang X, Sun K, Lu B. Individualized contrast agents injection protocol tailored to body surface area in coronary computed tomography angiography. Acta Radiol 2019; 60:1430-1437. [PMID: 31081338 DOI: 10.1177/0284185119840769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Yitong Yu
- Department of Radiologic Imaging, Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
- State Key Laboratory and National Center for Cardiovascular Diseases, Beijing, People’s Republic of China
| | - Weihua Yin
- Department of Radiologic Imaging, Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
- State Key Laboratory and National Center for Cardiovascular Diseases, Beijing, People’s Republic of China
| | - Kai Liao
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China
| | - Ting Liu
- Department of Radiology, the First Affiliated Hospital of China Medical University, Shenyang, Liaoning, People’s Republic of China
| | - Ximing Wang
- Shandong Medical Imaging Research Institute, Shandong University, Jinan, People’s Republic of China
| | - Kai Sun
- Department of Radiology, Baotou Central Hospital, Inner Mongolia, People’s Republic of China
| | - Bin Lu
- Department of Radiologic Imaging, Fuwai Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
- State Key Laboratory and National Center for Cardiovascular Diseases, Beijing, People’s Republic of China
| |
Collapse
|
4
|
Duran ES, Ahmad F, Elshikh M, Masood I, Duran C. Computed Tomography Imaging Findings of Acute Aortic Pathologies. Cureus 2019; 11:e5534. [PMID: 31687308 PMCID: PMC6819069 DOI: 10.7759/cureus.5534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Acute aortic syndromes (AAS) encompass a spectrum of life-threatening conditions characterized by acute aortic pain. AAS include acute aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, and aneurysm rupture. The prognosis of AAS is clearly related to prompt diagnosis and appropriate management. The different types of AAS cannot be reliably differentiated solely based on clinical presentation since the clinical features are indistinguishable. Multidetector-row computed tomography (MDCT) with electrocardiographic gating (ECG-gated MDCT) has been used in the acute emergency setting as a powerful clinical tool, which enables rapid and specific diagnosis of aortic pathologies. ECG-gated MDCT significantly reduces motion artifact and avoids potential pitfalls in the diagnosis of AAS. The aim of this review is to evaluate the role of MDCT imaging in the assessment of AAS and to discuss the differentiation of this spectrum of aortic diseases with reference to the key imaging findings.
Collapse
Affiliation(s)
- Elif S Duran
- Radiology, University of Texas Health Rio Grande Valley School of Medicine, Edinburg, USA
| | - Farhan Ahmad
- Radiology, University of Texas Medical Branch at Galveston, Galveston, USA
| | - Mohamed Elshikh
- Radiology, University of Texas Medical Branch at Galveston, Galveston, USA
| | - Irfan Masood
- Radiology, University of Texas Medical Branch at Galveston, Galveston, USA
| | - Cihan Duran
- Radiology, University of Texas Medical Branch at Galveston, Galveston, USA
| |
Collapse
|
5
|
Shirasaka T, Nagao M, Yamasaki Y, Kojima T, Kondo M, Shimomiya Y, Kamitani T, Honda H. Feasible scan timing for 320-row coronary CT angiography generated by the time to peak in the ascending aorta. Clin Imaging 2019; 54:153-158. [PMID: 30658213 DOI: 10.1016/j.clinimag.2019.01.005] [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: 08/06/2018] [Revised: 12/28/2018] [Accepted: 01/07/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE A 320-row CT scanner can briefly scan the entire heart. Therefore, the feasible scan timing is required. The aim of this study was to propose a refined method for feasible scan timing for coronary CT angiography (CCTA) using a time-density curve of the ascending aorta (AAo). METHODS One-hundred and twenty-nine patients were prospectively enrolled. All patients were performed test-bolus method. For the initial 65 patients, the scan timing was determined as a 3.0 s delay at the peak time in the AAo, which was defined as the conventional protocol (COV-P). For the next 64 patients, a scan timing of 1.0, 3.0, or 5.0 s delay was determined according to the interval from the contrast media arrival to peak time in the AAo, which was defined as the arrival to peak protocol (AP-P). The optimal scan timing was identified by the measurement of CT number in the left atrium, left ventricle, AAo, and descending aorta. The coronary enhancement and heterogeneity were compared between the two protocols. RESULTS The optimal scan timing was significantly higher in the AP-P than in the COV-P (85.9% vs. 61.5%, p = 0.0017). The CT number in the left circumflex artery (LCX) was significantly higher in the AP-P than the COV-P (344.5 Hounsfield units vs. 316.3 Hounsfield units, p = 0.0484). The heterogeneous index of the LCX was significantly greater for the COV-P than the AP-P (-36.8 vs. -25.8, p = 0.0028). CONCLUSIONS The AP-P can be used to determine the optimal scan timing for CCTA and contributes to stable coronary enhancement.
Collapse
Affiliation(s)
- Takashi Shirasaka
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3 Chome-1-1 Maidashi, Higashi Ward, Fukuoka, Fukuoka Prefecture 812-8582, Japan.
| | - Michinobu Nagao
- Department of Diagnostic Imaging & Nuclear Medicine, Tokyo Women's Medical University, 8-1 Kawata-cho, Shinjuku-ku, Tokyo 162-0054, Japan
| | - Yuzo Yamasaki
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3 Chome-1-1 Maidashi, Higashi Ward, Fukuoka, Fukuoka Prefecture 812-8582, Japan
| | - Tsukasa Kojima
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3 Chome-1-1 Maidashi, Higashi Ward, Fukuoka, Fukuoka Prefecture 812-8582, Japan
| | - Masatoshi Kondo
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3 Chome-1-1 Maidashi, Higashi Ward, Fukuoka, Fukuoka Prefecture 812-8582, Japan
| | - Yamato Shimomiya
- Ziosoft Inc., Mita Kokusai Bldg, 5F 1-4-28, Mita, Minato-ku, Tokyo 108-0073, Japan
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3 Chome-1-1 Maidashi, Higashi Ward, Fukuoka, Fukuoka Prefecture 812-8582, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3 Chome-1-1 Maidashi, Higashi Ward, Fukuoka, Fukuoka Prefecture 812-8582, Japan
| |
Collapse
|
6
|
Matsumoto Y, Higaki T, Masuda T, Sato T, Nakamura Y, Tatsugami F, Awai K. Minimizing individual variations in arterial enhancement on coronary CT angiographs using "contrast enhancement optimizer": a prospective randomized single-center study. Eur Radiol 2018; 29:2998-3005. [PMID: 30421021 DOI: 10.1007/s00330-018-5823-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/20/2018] [Accepted: 10/03/2018] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To investigate the clinical utility of our newly developed contrast enhancement optimizer (CEO) software for coronary CT angiography (CCTA). METHODS We randomly assigned 295 patients (168 males, 127 females, median age 71 years) undergoing CCTA to one of two contrast media injection protocols. Group A (n = 150) was injected with a CEO-selected iodine dose based on patient factors. In group B (n = 145), we used our standard protocol (245 mg I/kg). We recorded the CT number in the ascending aorta and determined whether the CT number was equivalent in groups A and B. For the equivalence test, we adopted 75 Hounsfield units (HU) as the equivalence margin. The standard deviation in the CT number and the rate of patients with an acceptable CT number were compared using the F test and the chi-square test, respectively. RESULTS The iodine dose in group A was significantly smaller than that in group B (235.7 vs. 253.6 mg I/kg, p < 0.001). The CT number of the ascending aorta was 428.6 ± 55.5 HU in group A and 436.1 ± 68.7 HU in group B; the 95% confidence interval for the difference between the groups was -4.3 HU to 16.9 HU and within the range of the predetermined equivalence margins. In group A, the variance was significantly smaller than that in group B (p = 0.009). The number of patients with an acceptable CT number was significantly higher in group A than in group B (84.7% vs. 71.7%, p = 0.007). CONCLUSIONS The use of our CEO for CCTA studies yielded optimal aortic contrast enhancement in significantly more patients than the standard protocol based on the body weight. KEY POINTS • With our contrast enhancement optimizer (CEO) software, optimal and stable aortic enhancement can be obtained on coronary CT angiography scans irrespective of patient factors. • Management of contrast media becomes more appropriate by the CEO software. • The CEO software can control contrast enhancement at different tube voltage levels.
Collapse
Affiliation(s)
- Yoriaki Matsumoto
- Department of Radiological Technology, Tsuchiya General Hospital, 3-30 Nakajima-cho, Naka-ku, Hiroshima, 730-8655, Japan. .,Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
| | - Toru Higaki
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Takanori Masuda
- Department of Radiological Technology, Tsuchiya General Hospital, 3-30 Nakajima-cho, Naka-ku, Hiroshima, 730-8655, Japan.,Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Tomoyasu Sato
- Department of Radiology, Tsuchiya General Hospital, 3-30 Nakajima-cho, Naka-ku, Hiroshima, 730-8655, Japan
| | - Yuko Nakamura
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Fuminari Tatsugami
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan
| |
Collapse
|
7
|
Nguyen TC, Ohyama Y, Taketomi-Takahashi A, Nguyen HT, Sugimoto A, Sato M, Sumiyoshi H, Nakamura T, Kurabayashi M, Tsushima Y. Influence of cardiac function on image quality in coronary computed tomography angiography. Clin Imaging 2018; 53:58-64. [PMID: 30312856 DOI: 10.1016/j.clinimag.2018.10.010] [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] [Received: 03/09/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To evaluate the correlation between cardiac functional parameters and image quality in coronary computed tomography angiography (CCTA). MATERIAL AND METHODS Sixty-six patients who underwent both CCTA and echocardiography were included. The coronary artery attenuation values and contrast-to-noise ratios (CNR) were measured in the proximal right coronary arteries (RCA) and left main (LM) trunk. Then, the averages of the mean values derived from RCA and LM were calculated. The cardiac output (CO), left atrial (LA) volume, and early mitral inflow velocity to mitral annular early diastolic velocity ratio (E/e') were measured by echocardiography. The relationship of cardiac parameters with arterial attenuation and CNR were assessed by Pearson's correlation, Spearman's rank correlation and multivariable linear regression analysis adjusted for age, gender, body surface area and heart rate. RESULTS The coronary artery attenuation value was negatively correlated with CO (r = -0.30, p = 0.01) and LA volume (r = -0.37, p = 0.002). CNR was negatively correlated with LA volume (r = -0.4, p = 0.001) and E/e' (r = -0.27, p = 0.03). These associations remained significant in the multivariable analysis. CONCLUSION CO and diastolic function had an impact on image quality of CCTA. Adjusting CCTA protocol may improve image quality in patients with known diastolic dysfunction or reduced cardiac output.
Collapse
Affiliation(s)
- Tien C Nguyen
- Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Japan; Department of Diagnostic Radiology, Bach Mai Hospital, Viet Nam
| | - Yoshiaki Ohyama
- Clinical Investigation and Research Unit, Gunma University Hospital, Japan.
| | - Ayako Taketomi-Takahashi
- Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Japan
| | - Huong T Nguyen
- Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Japan; Department of Diagnostic Radiology, Bach Mai Hospital, Viet Nam
| | | | - Makito Sato
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Japan
| | - Hisako Sumiyoshi
- Clinical Investigation and Research Unit, Gunma University Hospital, Japan
| | - Tetsuya Nakamura
- Clinical Investigation and Research Unit, Gunma University Hospital, Japan
| | - Masahiko Kurabayashi
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Japan
| | - Yoshito Tsushima
- Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Japan; Research Program for Diagnostic and Molecular Imaging, Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research (GIAR), Gunma, Japan
| |
Collapse
|
8
|
Shi L, Fujioka K, Sakurai-Ozato N, Fukumoto W, Satoh K, Sun J, Awazu A, Tanaka K, Ishida M, Ishida T, Nakano Y, Kihara Y, Hayes CN, Aikata H, Chayama K, Ito T, Awai K, Tashiro S. Chromosomal Abnormalities in Human Lymphocytes after Computed Tomography Scan Procedure. Radiat Res 2018; 190:424-432. [PMID: 30040044 DOI: 10.1667/rr14976.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The incidence of chromosomal abnormalities and cancer risk correlates well with the radiation dose after exposure to moderate- to high-dose ionizing radiation. However, the biological effects and health risks at less than 100 mGy, e.g., from computed tomography (CT) have not been ascertained. To investigate the biological effects of low-dose exposure from a CT procedure, we examined chromosomal aberrations, dicentric and ring chromosomes (dic+ring), in peripheral blood lymphocytes (PBLs), using FISH assays with telomere and centromere PNA probes. In 60 non-cancer patients exposed to CT scans, the numbers of dicentric and ring chromosomes were significantly increased with individual variation. The individual variations in the increment of dicentric and ring chromosomes after CT procedures were confirmed using PNA-FISH analysis of PBLs from 15 healthy volunteers after in vitro low-dose exposure using a 137Cs radiation device. These findings strongly suggest that appropriate medical use of low-dose radiation should consider individual differences in radiation sensitivity.
Collapse
Affiliation(s)
- Lin Shi
- Departments of a Cellular Biology
| | | | | | - Wataru Fukumoto
- g Department of Diagnostic Radiology, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kenichi Satoh
- c Environmetrics and Biometrics, Research Institute for Radiation Biology Medicine
| | | | - Akinori Awazu
- h Department of Mathematics.,i Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi Hiroshima 739-8530, Japan
| | | | - Mari Ishida
- d Departments of Cardiovascular Physiology and Medicine
| | - Takafumi Ishida
- j Department of Cardiovascular Medicine, Fukushima Medical University, Fukushima 960-1295, Japan
| | | | | | - C Nelson Hayes
- f Gastroenterology and Metabolism, Biomedical Sciences, Graduate School of Biomedical and Health Sciences
| | - Hiroshi Aikata
- f Gastroenterology and Metabolism, Biomedical Sciences, Graduate School of Biomedical and Health Sciences
| | - Kazuaki Chayama
- f Gastroenterology and Metabolism, Biomedical Sciences, Graduate School of Biomedical and Health Sciences
| | - Takashi Ito
- k Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki 852-8523, Japan
| | - Kazuo Awai
- g Department of Diagnostic Radiology, Hiroshima University, Hiroshima 734-8553, Japan
| | - Satoshi Tashiro
- Departments of a Cellular Biology.,i Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi Hiroshima 739-8530, Japan
| |
Collapse
|
9
|
The Choice of Gadolinium-Based Contrast Agents: A Radiologist’s Responsibility between Pharmaceutical Equivalence and Bioethical Issues. Symmetry (Basel) 2017. [DOI: 10.3390/sym9110287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
|
10
|
Bui TD, Gelfand D, Whipple S, Wilson SE, Fujitani RM, Conroy R, Pham H, Gordon IL. Comparison of CT and Catheter Arteriography for Evaluation of Peripheral Arterial Disease. Vasc Endovascular Surg 2016; 39:481-90. [PMID: 16382269 DOI: 10.1177/153857440503900604] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Computed tomographic arteriography (CTA) has emerged as a promising technique for less invasive imaging of the lower extremity arteries. The aim of this study was to determine the concordance between CTA and catheter arteriography (CA) in patients with peripheral arterial disease (PAD). Twenty-five patients underwent both CTA and CA, and each set of images was interpreted independently by 3 readers. The infrarenal arteries were divided into 16 segments, and each segment was scored as: 1 = stenosis <50%; 2 = 50–99% stenosis; 3 = occlusion. Modal scores from 3 readers were used to compare results for each segment, with CA assumed to represent true arterial anatomy. Agreement between CTA and CA readings was defined as: concordance (modal scores were identical); moderate discrepancy (MD) (modal scores differed by 1); or severe discrepancy (SD) (modal scores differed by 2). In total, 718 segments were assessed by both CTA and CA. For all segments, the sensitivity and specificity of CTA for <50% stenosis was 86% and 90%; for 50–99% stenosis, sensitivity and specificity were 79% and 89%; and for occlusion, 85% and 98%. Above-knee (AK) CTA scores had slightly better concordance of 86.1% than below-knee (BK) readings (82.3%) (p = 0.104). Severe discrepancies between AK CTA and CA scores were observed in 1.8% of segments compared to 5.4% of BK segments (p = 0.038). Poor CTA image quality was the cause in 20% of AK segments and 28% of BK segments. Poor CA image quality was the cause in 8% of AK and 7% of BK discrepancies. Registration disagreement (stenosis observed in a level in 1 study attributed to a different level in the other) accounted for 18% of AK and 17% of BK discrepancies. In 54% of AK and 48% of BK discrepancies, neither image quality nor registration errors were identified, indicating that inherent differences in the depiction of stenosis by CA and CTA were responsible. When discrepancies caused by registration error were excluded, SD observed in BK segments (4.0%) remained significantly higher than in AK segments (1.25%) (p = 0.029), and poor CTA quality image was the most common cause (76%) of severe BK discrepancies. In AK discrepancies without an identifiable technical cause, CTA uniformly showed more stenosis, suggesting greater CTA diagnostic precision in larger vessels. In general, agreement between CTA and CA was moderately good. Compared to CA, CTA may be better at depicting stenosis in large, proximal vessels owing to the superior accuracy of cross-sectional images in the measurement of stenosis. There appeared to be poorer CT resolution and higher frequency of severe discrepancies between CTA and CA in BK arteries.
Collapse
Affiliation(s)
- Trung D Bui
- VA Long Beach Healthcare System, Department of Vascular Surgery, Long Beach, CA and UCI Medical Center, Department of Vascular and Endovascular Surgery, Orange, CA 92868, USA.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Bostock IC, Zarkowsky DS, Hicks CW, Stone DH, Eslami MH, Malas MB, Goodney PP. Outcomes of Endovascular Aortic Aneurysm Repair in Kidney Transplant Recipients: Results From a National Quality Initiative. Am J Transplant 2016; 16:2395-400. [PMID: 26813253 PMCID: PMC5292261 DOI: 10.1111/ajt.13733] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 12/28/2015] [Accepted: 01/20/2016] [Indexed: 01/25/2023]
Abstract
Contrast-induced nephropathy after endovascular aortic aneurysm repair (EVAR) in kidney transplant recipients (KTRs) can have devastating consequences. The Vascular Quality Initiative (VQI) database was queried to select all KTRs who underwent EVAR between January 2003 and December 2014. Our primary outcome was renal dysfunction, defined as acute kidney injury (AKI; elevation of serum creatinine >0.5 mg/dL from baseline) or new postoperative hemodialysis requirement. Within the EVAR VQI dataset, 40 patients were KTRs (40 of 17 213, or 0.2%). Renal dysfunction occurred in five of 40 patients in the KTR group in comparison to 779 of 17 173 patients in the nontransplanted group (12.5% versus 4.5%, p < 0.01). Emergent EVAR was required in 2 (5%) patients, one of whom required dialysis after surgery and subsequently died. One-year survival after EVAR was similar in the two groups (92.9% versus 93.1%, p = 0.73). KTRs who developed renal dysfunction had significantly lower preoperative estimated glomerular filtration rates (eGFRs) (29.5 versus 54.7, p = 0.007) and a significantly higher iodine:eGFR ratio (0.78 versus 0.39, p = 0.02) despite receiving a similar volume of contrast (70.0 versus 68.8, p = 0.97). Renal dysfunction is 3 times more frequent in KTRs treated with EVAR, though overall survival did not differ between the groups. Decreased preoperative eGFR and a higher iodine:eGFR ratio are associated with postoperative renal dysfunction.
Collapse
Affiliation(s)
- I. C. Bostock
- Division of Vascular and Endovascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - D. S. Zarkowsky
- Division of Vascular and Endovascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - C. W. Hicks
- Department of Surgery, The Johns Hopkins Institutes, Baltimore, MD
| | - D. H. Stone
- Division of Vascular and Endovascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - M. H. Eslami
- Division of Vascular and Endovascular Surgery, Boston University School of Medicine, Boston, MA
| | - M. B. Malas
- Department of Surgery, The Johns Hopkins Institutes, Baltimore, MD
| | - P. P. Goodney
- Division of Vascular and Endovascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| |
Collapse
|
12
|
Mihl C, Kok M, Altintas S, Kietselaer BLJH, Turek J, Wildberger JE, Das M. Evaluation of individually body weight adapted contrast media injection in coronary CT-angiography. Eur J Radiol 2016; 85:830-6. [PMID: 26971431 DOI: 10.1016/j.ejrad.2015.12.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 11/14/2015] [Accepted: 12/29/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Contrast media (CM) injection protocols should be customized to the individual patient. Aim of this study was to determine if software tailored CM injections result in diagnostic enhancement of the coronary arteries in computed tomography angiography (CTA) and if attenuation values were comparable between different weight categories. MATERIALS AND METHODS 265 consecutive patients referred for routine coronary CTA were scanned on a 2nd generation dual-source CT. Group 1 (n=141) received an individual CM bolus based on weight categories (39-59 kg; 60-74 kg; 75-94 kg; 95-109 kg) and scan duration ('high-pitch: 1s; "dual-step prospective triggering": 7s), as determined by contrast injection software (Certegra™ P3T, Bayer, Berlin, Germany). Group 2 (n=124) received a standard fixed CM bolus; Iopromide 300 mgI/ml; volume: 75 ml; flow rate: 7.2 ml/s. Contrast enhancement was measured in all proximal and distal coronary segments. Subjective and objective image quality was evaluated. Statistical analysis was performed using SPSS (IBM, version 20.0). RESULTS For group 1, mean attenuation values of all segments were diagnostic (>325 HU) without statistical significant differences between different weight categories (p>0.17), proximal vs. distal: 449 ± 65-373 ± 58 HU (39-59 kg); 443 ± 69-367 ± 81 HU (60-74 kg); 427 ± 59-370 ± 61 HU (75-94 kg); 427 ± 73-347 ± 61 HU (95-109 kg). Mean CM volumes were: 55 ± 6 ml (39-59 kg); 61 ± 7 ml (60-74 kg); 71 ± 8 ml (75-94 kg); 84 ± 9 ml (95-109 kg). For group 2, mean attenuation values were not all diagnostic with differences between weight categories (p<0.01), proximal vs. distal: 611 ± 142-408 ± 69 HU (39-59 kg); 562 ± 135-389 ± 98 HU (60-74 kg); 481 ± 83-329 ± 81 HU (75-94 kg); 420 ± 73-305 ± 35 HU (95-109 kg). Comparable image noise and image quality were found between groups (p ≥ 0.330). CONCLUSIONS Individually tailored CM injection protocols yield diagnostic attenuation and a more homogeneous enhancement pattern between different weight groups. CM volumes could be reduced for the majority of patients utilizing individualized CM bolus application.
Collapse
Affiliation(s)
- Casper Mihl
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Madeleine Kok
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Sibel Altintas
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Bas L J H Kietselaer
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Jakub Turek
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands; CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands
| |
Collapse
|
13
|
Coronary CT angiography using low concentrated contrast media injected with high flow rates: Feasible in clinical practice. Eur J Radiol 2015; 84:2155-60. [PMID: 26277498 DOI: 10.1016/j.ejrad.2015.06.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 06/01/2015] [Accepted: 06/24/2015] [Indexed: 11/24/2022]
Abstract
PURPOSE Aim of this study was to test the hypothesis that peak injection pressures and image quality using low concentrated contrast media (CM) (240 mg/mL) injected with high flow rates will be comparable to a standard injection protocol (CM: 300 mg/mL) in coronary computed tomographic angiography (CCTA). MATERIAL AND METHODS One hundred consecutive patients were scanned on a 2nd generation dual-source CT scanner. Group 1 (n=50) received prewarmed Iopromide 240 mg/mL at an injection rate of 9 mL/s, followed by a saline chaser. Group 2 (n=50) received the standard injection protocol: prewarmed Iopromide 300 mg/mL; flow rate: 7.2 mL/s. For both protocols, the iodine delivery rate (IDR, 2.16 gI/s) and the total iodine load (22.5 gI) were kept identical. Injection pressure (psi) was continuously monitored by a data acquisition program. Contrast enhancement was measured in the thoracic aorta and all proximal and distal coronary segments. Subjective and objective image quality was evaluated between both groups. RESULTS No significant differences in peak injection pressures were found between both CM groups (121 ± 5.6 psi vs. 120 ± 5.3 psi, p=0.54). Flow rates of 9 mL/s were safely injected without any complications. No significant differences in contrast-to-noise ratio, signal-to-noise ratio and subjective image quality were found (all p>0.05). No significant differences in attenuation levels were found in the thoracic aorta and all segments of the coronary arteries (all p>0.05). CONCLUSION Usage of low iodine concentration CM and injection with high flow rates is feasible. High flow rates (9 mL/s) of Iopromide 240 were safely injected without complications and should not be considered a drawback in clinical practice. No significant differences in peak pressure and image quality were found. This creates a doorway towards applicability of a broad variety in flow rates and IDRs and subsequently more individually tailored injection protocols.
Collapse
|
14
|
Piechowiak EI, Peter JFW, Kleb B, Klose KJ, Heverhagen JT. Intravenous Iodinated Contrast Agents Amplify DNA Radiation Damage at CT. Radiology 2015; 275:692-7. [DOI: 10.1148/radiol.14132478] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
15
|
Assessment of Single-Bolus Contrast Administration Technique Using Hybrid Dual-Source ECG-Gated Thoracic and Dual-Source Non–ECG-Gated High-Pitch Abdominopelvic CT Acquisitions for Procedural Planning Before Transcatheter Aortic Valve Replacement. J Comput Assist Tomogr 2015; 39:207-12. [DOI: 10.1097/rct.0000000000000194] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
16
|
Abstract
Computed tomography angiography (CTA) with multiple detector-row CT (MDCT) has evolved into an established technique for non-invasive imaging of renal and mesenteric vessels. With adequate selection of acquisition parameters (thin collimation) high spatial-resolution volumetric data sets for subsequent 2D and 3D reformation can be acquired. Contrast medium (CM) injection parameters need to be adjusted to the acquisition speed of the scanners. Whereas fast acquisitions allow a reduction of total CM volume in the setting of CTA, this is not the case when CTA is combined with a second-phase abdominal MDCT acquisition for parenchymal (e.g., hepatic) imaging. Renal CTA is an accurate and reliable test for visualizing vascular anatomy and renal artery stenosis, and therefore a viable alternative to MRA in the assessment of patients with renovascular hypertension and in potential living related renal donors. CTA, combined with abdominal/parenchymal MDCT is a first-line diagnostic test in patients with suspected abdominal vascular emergencies, such as acute mesenteric ischemia, and an excellent tool to assess a wide variety of vascular abnormalities of the abdominal viscera.
Collapse
Affiliation(s)
- Dominik Fleischmann
- Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, Room S-072, Stanford, CA 94305-5105, USA.
| |
Collapse
|
17
|
Kidoh M, Nakaura T, Nakamura S, Awai K, Utsunomiya D, Namimoto T, Harada K, Yamashita Y. Novel contrast-injection protocol for coronary computed tomographic angiography: contrast-injection protocol customized according to the patient's time-attenuation response. Heart Vessels 2013; 29:149-55. [PMID: 23512260 DOI: 10.1007/s00380-013-0338-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/01/2013] [Indexed: 01/03/2023]
Abstract
We developed a new individually customized contrast-injection protocol for coronary computed tomography (CT) angiography based on the time-attenuation response in a test bolus, and investigated its clinical applicability. We scanned 60 patients with suspected coronary diseases using a 64-detector CT scanner, who were randomly assigned to one of two protocols. In protocol 1 (P1), we estimated the contrast dose to yield a peak aortic attenuation of 400 HU based on the time-attenuation response to a small test-bolus injection (0.3 ml/kg body weight) delivered over 9 s. Then we administered a customized contrast dose over 9 s. In protocol 2 (P2), the dose was tailored to the patient's body weight; this group received 0.7 ml/kg body weight with an injection duration of 9 s. We compared the two protocols for dose of contrast medium, peak attenuation, variations in attenuation values of the ascending aorta, and the success rate of adequate attenuation (250-350 HU) of the coronary arteries. The contrast dose was significantly smaller in P1 than in P2 (36.9 ± 9.2 vs 43.1 ± 7.0 ml, P < 0.01). Peak aortic attenuation was significantly less under P1 than under P2 (384.1 ± 25.0 vs 413.5 ± 45.7, P < 0.01). The mean variation (standard deviation) of the attenuation values was smaller in P1 than in P2 (25.0 vs 45.7, P < 0.01). The success rate of adequate attenuation of the coronary arteries was significantly higher with P1 than with P2 (85.0 vs 65.8 %, P < 0.01). P1 facilitated a reduction in the contrast dose, reduced the individual variations in peak aortic attenuation, and achieved optimal coronary CT attenuation (250-350 HU) more frequently than P2.
Collapse
Affiliation(s)
- Masafumi Kidoh
- Diagnostic Radiology, Amakusa Medical Center, Kameba 854-1, Amakusa, Kumamoto, 863-0046, Japan,
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Kidoh M, Nakaura T, Oda S, Namimoto T, Awai K, Yoshinaka I, Harada K, Yamashita Y. Contrast Enhancement During Hepatic Computed Tomography. J Comput Assist Tomogr 2013; 37:159-64. [DOI: 10.1097/rct.0b013e31827dbc08] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
19
|
Saade C, Bourne R, Wilkinson M, Evanoff M, Brennan P. A reduced contrast volume acquisition regimen based on cardiovascular dynamics improves visualisation of head and neck vasculature with carotid MDCT angiography. Eur J Radiol 2012; 82:e64-9. [PMID: 23088881 DOI: 10.1016/j.ejrad.2012.09.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 08/31/2012] [Accepted: 09/06/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate enhancement of head and neck arteries during carotid computed tomography angiography using a reduced volume contrast regimen and craniocaudal scan acquisition. MATERIALS AND METHODS Two hundred and two patients underwent carotid angiography using a 64 channel computed tomography scanner. Patients were allocated to one of two acquisition/contrast regimens: regimen A, the department's standard protocol, consisting of a caudocranial scan direction with 100mL of contrast intravenously; regimen B, involving a craniocaudal scan direction and approximately 50 mL of contrast using a timing dictated by patient hemodynamics. Attenuation profiles of cranial arteries and veins in 6 anatomical segments were assessed and arteriovenous contrast ratios (AVCR) calculated. Receiver operating characteristic (ROC) analysis was performed using DBM methodology. RESULTS Arterial attenuation was up to 54% (p<0.01) higher following regimen B compared with A. Attenuation in the veins were significantly lower in regimen B than in regimen A with a maximum reduction of up to 93% (p<0.0001). With regimen B, there were significant (p<0.0001) improvements in AVCR at a variety of anatomical sites. The ROC analysis demonstrated a significantly higher Az score for the novel regimen compared with regimen A (p<0.002) with inter-neuroradiologist agreement increasing from poor to moderate. CONCLUSION Significant improvements in visualisation of head and neck arterial vasculature can be achieved with a CT acquisition regimen using low contrast volume and injection timing based on patient specific contrast formula and craniocaudal scan direction.
Collapse
Affiliation(s)
- Charbel Saade
- Department of Radiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
| | | | | | | | | |
Collapse
|
20
|
Pathe C, Eble K, Schmitz-Beuting D, Keil B, Kaestner B, Voelker M, Kleb B, Klose KJ, Heverhagen JT. The presence of iodinated contrast agents amplifies DNA radiation damage in computed tomography. CONTRAST MEDIA & MOLECULAR IMAGING 2011; 6:507-13. [DOI: 10.1002/cmmi.453] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Caroline Pathe
- Department of Diagnostic Radiology; Philipps University; Marburg; Germany
| | - Katharina Eble
- Department of Diagnostic Radiology; Philipps University; Marburg; Germany
| | | | | | - Bjoern Kaestner
- Department of Diagnostic Radiology; Philipps University; Marburg; Germany
| | - Maximilian Voelker
- Department of Diagnostic Radiology; Philipps University; Marburg; Germany
| | - Beate Kleb
- Department of Diagnostic Radiology; Philipps University; Marburg; Germany
| | - Klaus J. Klose
- Department of Diagnostic Radiology; Philipps University; Marburg; Germany
| | | |
Collapse
|
21
|
Saba L, Anzidei M, Lucatelli P, Mallarini G. The multidetector computed tomography angiography (MDCTA) in the diagnosis of splenic artery aneurysm and pseudoaneurysm. Acta Radiol 2011; 52:488-98. [PMID: 21498313 DOI: 10.1258/ar.2011.100283] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Splenic artery aneurysm is the most frequent visceral artery aneurysm and rupture of the aneurysm is associated with a high mortality rate. It is important to discriminate between a true aneurysm and a pseudoaneurysm that may be caused by pancreatitis, iatrogenic and postoperative causes, trauma and peptic ulcer disease. Multidetector-row CT angiography (MDCTA) allows detailed visualization of the vascular anatomy and may allow identification of aneurysms and pseudoaneurysms that affect the splenic artery. The objective of this article is to provide a review of the general characteristics of splenic artery aneurysms and pseudoaneurysms and to describe the findings of MDCTA.
Collapse
Affiliation(s)
- Luca Saba
- Department of Radiology, Azienda Ospedaliero Universitaria (AOU), Cagliari
| | - Michele Anzidei
- Department of Radiological Sciences, University of Rome La Sapienza, Rome, Italy
| | - Pierleone Lucatelli
- Department of Radiological Sciences, University of Rome La Sapienza, Rome, Italy
| | - Giorgio Mallarini
- Department of Radiology, Azienda Ospedaliero Universitaria (AOU), Cagliari
| |
Collapse
|
22
|
Low dose dual-source CT angiography of the thoracic aorta. Int J Cardiovasc Imaging 2010; 27:1025-34. [DOI: 10.1007/s10554-010-9742-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Accepted: 10/27/2010] [Indexed: 10/18/2022]
|
23
|
Sattler B, Lee JA, Lonsdale M, Coche E. PET/CT (and CT) instrumentation, image reconstruction and data transfer for radiotherapy planning. Radiother Oncol 2010; 96:288-97. [PMID: 20709416 DOI: 10.1016/j.radonc.2010.07.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 07/08/2010] [Accepted: 07/08/2010] [Indexed: 10/19/2022]
Abstract
The positron emission tomography in combination with CT in hybrid, cross-modality imaging systems (PET/CT) gains more and more importance as a part of the treatment-planning procedure in radiotherapy. Positron emission tomography (PET), as a integral part of nuclear medicine imaging and non-invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy. By the choice of the PET-Tracer, a variety of different metabolic processes can be visualized. First and foremost, this is the glucose metabolism of a tissue as well as for instance hypoxia or cell proliferation. This paper comprises the system characteristics of hybrid PET/CT systems. Acquisition and processing protocols are described in general and modifications to cope with the special needs in radiooncology. This starts with the different position of the patient on a special table top, continues with the use of the same fixation material as used for positioning of the patient in radiooncology while simulation and irradiation and leads to special processing protocols that include the delineation of the volumes that are subject to treatment planning and irradiation (PTV, GTV, CTV, etc.). General CT acquisition and processing parameters as well as the use of contrast enhancement of the CT are described. The possible risks and pitfalls the investigator could face during the hybrid-imaging procedure are explained and listed. The interdisciplinary use of different imaging modalities implies a increase of the volume of data created. These data need to be stored and communicated fast, safe and correct. Therefore, the DICOM-Standard provides objects and classes for this purpose (DICOM RT). Furthermore, the standard DICOM objects and classes for nuclear medicine (NM, PT) and computed tomography (CT) are used to communicate the actual image data created by the modalities. Care must be taken for data security, especially when transferring data across the (network-) borders of different hospitals. Overall, the most important precondition for successful integration of functional imaging in RT treatment planning is the goal orientated as well as close and thorough communication between nuclear medicine and radiotherapy departments on all levels of interaction (personnel, imaging protocols, GTV delineation, and selection of the data transfer method).
Collapse
Affiliation(s)
- Bernhard Sattler
- Department of Nuclear Medicine, University Hospital Leipzig, Germany.
| | | | | | | |
Collapse
|
24
|
Contrast material injection protocol with the dose adjusted to the body surface area for MDCT aortography. AJR Am J Roentgenol 2010; 194:903-8. [PMID: 20308489 DOI: 10.2214/ajr.09.3460] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of our study was to investigate the effect on aortic enhancement of contrast material volumes adjusted for a patient's body surface area (BSA) at CT angiography (CTA). SUBJECTS AND METHODS A 64-MDCT scanner was used to perform CTA of the whole aorta in 89 patients (mean age, 68.7 years) with confirmed or suspected aortoiliac disease. The patients were divided into groups: a body weight (BW) group (n = 45) and a BSA (n = 44) group. The contrast dose was 360 mg I/kg BW in the BW group and 12,753 mg I/m(2) BSA in the BSA group. Because the average BW of Japanese adults is approximately 60 kg, the contrast dose in the two protocols was identical in patients weighing 60 kg. We compared aortic enhancement achieved with the two protocols using the two-tailed Student's t test, and we used the generalized linear model to analyze the effect of patient age, sex, and BW on aortic enhancement in each protocol group. RESULTS The mean aortic enhancement in the BW and BSA groups was 324.2 and 311.7 HU, respectively; the difference was not significant (p = 0.26). In the BW group, BW had a statistically significant effect on aortic enhancement (p < 0.01), whereas neither patient age nor sex did (p = 0.08 and 0.07, respectively). In the BSA group, the age, sex, BW, and BW by sex had no statistically significant effect on aortic enhancement (p = 0.33, 023, 0.10, and 0.16, respectively). CONCLUSION Under the BSA protocol, aortic enhancement tended to be consistent and adequate regardless of patient BW.
Collapse
|
25
|
Yang LH, Wu DK, Chen CY, Liu GC, Hsieh TJ, Jaw TS, Huang SY, Lin CC, Hsu JS. Quantitative assessment of image quality in 64-slice-computed tomography of coronary arteries in subjects undergoing screening for coronary artery disease. Kaohsiung J Med Sci 2010; 26:21-9. [PMID: 20040469 DOI: 10.1016/s1607-551x(10)70004-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Accurate and consistent visualization of the entire coronary system with high-grade imaging quality is crucial for routine applications of multi-detector-computed tomography (MDCT) coronary angiography. To determine the imaging quality of 64-slice-MDCT coronary angiography, we respectively explored the quantitative parameters of imaging quality in 105 consecutive subjects (71 men, 34 women; aged 58.66 +/- 10.62 years) who underwent 64-slice-MDCT coronary angiography to screen for coronary disease. The interobserver agreement for semi-quantitative image quality, visible length, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the coronary arteries was good. The SNR and CNR of the proximal segments of the coronary arteries were superior to that of the distal segments of coronary arteries (p < 0.001). The visible length of the stenosed right coronary artery was significantly shorter than that of the non-stenosed right coronary artery (p = 0.03). The SNR and CNR of the stenosed and non-stenosed coronary arteries revealed no significant difference (p > 0.05). Body weight and body mass index were inversely related to the SNR and CNR of the aorta (p < 0.001). In conclusion, 64-slice-MDCT coronary angiography can provide excellent imaging quality of coronary arteries in subjects undergoing screening for coronary disease, although the SNR and CNR were relatively low at the distal segments of coronary arteries.
Collapse
Affiliation(s)
- Li-Hwa Yang
- Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
|
27
|
Comparaison du scanner 64-détecteurs et de la coronarographie dans la détection des sténoses coronariennes chez des patients porteurs d’angor stable et de syndrome coronaire aigu à bas risques. ACTA ACUST UNITED AC 2009; 90:1055-66. [DOI: 10.1016/s0221-0363(09)73245-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
28
|
ROMANO L, GRAZIOLI L, BONOMO L, XU JR, CHEN KM, DORE R, VANZULLI A, CATALANO C. Enhancement and safety of iomeprol-400 and iodixanol-320 in patients undergoing abdominal multidetector CT. Br J Radiol 2009; 82:204-11. [DOI: 10.1259/bjr/93627766] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
29
|
Mühlenbruch G, Behrendt FF, Eddahabi MA, Knackstedt C, Stanzel S, Das M, Seidensticker P, Günther RW, Wildberger JE, Mahnken AH. Which Iodine concentration in chest CT? – A prospective study in 300 patients. Eur Radiol 2008; 18:2826-32. [PMID: 18651154 DOI: 10.1007/s00330-008-1080-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 05/12/2008] [Accepted: 05/17/2008] [Indexed: 10/21/2022]
|
30
|
Abstract
LEARNING OBJECTIVES Learning objectives of this paper are to review and to summarize the pathogenesis of bowel ischemia and to describe its clinical, pathological, and radiological manifestations. BACKGROUND Bowel ischemia is a common disorder produced by several causes, and it shows various clinical presentations connected with an high mortality. With the increase in average life expectancy, bowel ischemia represents one of the most threatening abdominal conditions in elderly patients. In the last decade, computed tomography has tremendously altered the diagnostic approach to bowel ischemia also influencing the therapeutic approach in the current practice. IMAGING FINDINGS Computed tomographic imaging findings include bowel wall thickening, portal venous gas, intramural pneumatosis, engorgement of mesenteric veins, loss or increase of bowel wall enhancement, and infarction of other abdominal organs. CONCLUSIONS Bowel ischemia shows a broad spectrum of radiological manifestations, and regardless of the primary causes, it produces similar radiological features. Bowel ischemia may simulate cancer or inflammatory conditions; so it is a mandatory tight integration between radiological and clinical signs.
Collapse
|
31
|
Abstract
Advancing multidetector technology offers opportunities for improved vascular assessment in children. Much of what is available deals with thoracic and central nervous system applications, with very little written about abdominal applications. That said, many of the technical aspects are similar to computed tomography (CT) angiography in these regions and are worthy of reviewing, in addition to those unique considerations for abdominal CT angiography (CTA) in children. Familiarity with appropriate abdominal CTA for pediatric multidetector array CT will provide the same opportunities as CTA in other regions.
Collapse
|
32
|
Keil S, Plumhans C, Behrendt FF, Das M, Stanzel S, Mühlenbruch G, Seidensticker P, Knackstedt C, Mahnken AH, Günther RW, Wildberger JE. MDCT angiography of the pulmonary arteries: intravascular contrast enhancement does not depend on iodine concentration when injecting equal amounts of iodine at standardized iodine delivery rates. Eur Radiol 2008; 18:1690-5. [DOI: 10.1007/s00330-008-0942-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 01/22/2008] [Accepted: 02/11/2008] [Indexed: 12/01/2022]
|
33
|
Salvolini L, Renda P, Fiore D, Scaglione M, Piccoli G, Giovagnoni A. Acute aortic syndromes: Role of multi-detector row CT. Eur J Radiol 2008; 65:350-8. [DOI: 10.1016/j.ejrad.2007.09.020] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 09/07/2007] [Accepted: 09/08/2007] [Indexed: 12/01/2022]
|
34
|
Kloska SP, Fischer T, Nabavi DG, Wessling J, Dittrich R, Fischbach R, Seidensticker P, Ringelstein EB, Heindel W. Comparison of different iodine concentration contrast media in perfusion computed tomography of the brain: is high iodine concentration useful? Invest Radiol 2007; 42:564-8. [PMID: 17620939 DOI: 10.1097/rli.0b013e318042b608] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To investigate maximum enhancement and visual map quality in cerebral perfusion computed tomography (PCT) with variation of iodine concentration of contrast media (CM). MATERIALS AND METHODS Two groups of 45 patients each, underwent PCT with either 370 mg iodine/mL (30 mL; 6 mL/s) or 300 mg iodine/mL (40 mL; 8 mL/s) CM, respectively, and similar total iodine dose. Parenchymal and vascular enhancement as well as contrast-to-noise ratio of superior sagittal sinus was measured on PCT source images. PCT maps were rated visually with dichotomized scale for diagnostic quality. RESULTS Enhancement and contrast-to-noise ratio of the superior sagittal sinus was significantly higher for the 370 mg iodine/mL protocol (P < 0.0002 and P < 0.007), whereas parenchymal enhancement was not significantly different. Diagnostic quality of PCT maps did not differ between both protocols (P < 0.557). CONCLUSIONS PCT using 370 mg iodine/mL CM can be reliably performed with reduced injection rate and less total volume enabling smaller diameter of intravenous canula compared with 300 mg iodine/mL CM.
Collapse
Affiliation(s)
- Stephan P Kloska
- Department of Clinical Radiology, University of Muenster, Muenster, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Schuknecht B. High-concentration contrast media (HCCM) in CT angiography of the carotid system: impact on therapeutic decision making. Neuroradiology 2007; 49 Suppl 1:S15-26. [PMID: 17665154 DOI: 10.1007/s00234-007-1469-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND CT angiography (CTA) is a minimally invasive technique that enables precise delineation of extracranial and intracranial vascular anatomy and pathology based on high intravascular density. With a 64-slice MDCT scanner, improved first-pass vascular visualization can be obtained with HCCM (400 mg I/ml) using 25 ml for combined intra-and extracranial studies and 20 ml for intracranial examinations alone. We reviewed 23 patients with extra-cranial stenoocclusive disease and 12 patients with intra-cranial aneurysms. Two additional patients presented with a mycotic aneurysm and a micro arteriovenous malformation (micro-AVM). RESULTS In 23 patients with 27 significant (> or =70%) vascular stenoses, high intraluminal contrast density and optimal projection of the stenosis profile facilitated precise delineation of the residual lumen in all vessels affected. Pseudoocclusion was present in 3 of the 27 vessels (11%) and ulceration in 5 (18.5%). CTA, in contrast to digital subtraction angiography (DSA) and magnetic resonance angiography (MRA), was able to delineate the mural constituents of stenoses, particularly marked calcification (present in 17 of 27 vessels, 62.9%). Eccentric vessel wall narrowing indicated dissection in three vessels (11%) and circular postradiation fibrosis was found in two vessels (7.4%). High-quality CTA obviated the need for DSA for diagnostic purposes in every patient. The decision regarding surgical treatment in nine vessels (33%) was influenced by the location of the stenosis relative to the carotid bifurcation, the length of the stenosis, and the level of the carotid bifurcation. Endovascular treatment in 12 vessels (44.4%) and the appropriate choice and placement of endovascular devices was affected by the anatomic configuration of the supraaortic vessels, and by the intrastenotic dimensions relative to the dimensions of the vessel proximal and distal to the stenosis. The anatomic availability of collaterals, relevant for both treatments, was determined via the anterior communicating artery (ACoA) in 91.3% of patients and the posterior communicating artery (PCoA) in 80.4% of patients. Intracranial CTA displayed the lesion location, configuration, size, and orientation in each of the 12 patients with intracranial aneurysms and in the two patients with a micro-AVM and a mycotic aneurysm. The correct diagnosis was established prior to DSA in each patient. Following CTA, the role of DSA was relegated to endovascular therapy in three aneurysms. For surgical candidates, DSA served to exclude potential multiplicity in ten saccular aneurysms and in one mycotic aneurysm. CTA provided information supplementary to DSA in 11 of the 13 aneurysms (84.6%). Delineation of blebs, calcification, thrombus, or incorporation of branches facilitated risk stratification with respect to rupture and to surgical or endovascular treatment. CONCLUSION Advantages of CTA, such as virtual independence from the hemodynamic situation, delineation of landmarks and vessel wall calcification, and the ability to quantify vessels and aneurysms, distinguish this technique from other noninvasive vascular imaging techniques and DSA. Acquired with the use of iodinated HCCM, CT angiograms permit excellent recognition of appropriate diagnostic and interventional treatment paths, thereby facilitating improved decision-making regarding endovascular or surgical treatment.
Collapse
Affiliation(s)
- Bernhard Schuknecht
- Medizinisch Radiologisches Institut Zürich, Bahnhofplatz 3, 8001 Zürich, Switzerland.
| |
Collapse
|
36
|
Rau MM, Setty BN, Blake MA, Ouellette-Piazzo K, Hahn PF, Sahani DV. Evaluation of Renal Transplant Donors with 16-Section Multidetector CT Angiography: Comparison of Contrast Media with Low and High Iodine Concentrations. J Vasc Interv Radiol 2007; 18:603-9. [PMID: 17494841 DOI: 10.1016/j.jvir.2007.02.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
PURPOSE To compare the degree of contrast enhancement, image quality, and accuracy of renal computed tomographic (CT) angiography performed with a 16-detector row CT unit and equal iodine doses of low- and high-iodine-concentration contrast medium in the evaluation of renal transplant donors. MATERIALS AND METHODS Eighty donors scheduled to undergo renal CT angiography with 16-detector row CT were administered nonionic contrast media with two iodine concentrations. The first group (group A, n=40) received a contrast medium with 300 mg of iodine per milliliter, and the second group (group B, n=40) received a contrast medium with 370 mg of iodine per milliliter. An equal iodine dose of 550 mg per kilogram body weight was given to both groups. Contrast enhancement was quantified by measuring attenuation in the abdominal aorta and in both renal arteries. Subjective assessment of contrast enhancement, quality of reformatted images, and visualization of branch order of renal arteries were rated with a 5-point scale. The number of renal arteries and veins seen at CT was correlated with the results at surgery. RESULTS The mean enhancement values in group B were significantly greater (P<.001) than those in group A. The mean HU (+/-standard deviation) in groups A and B were 298+/-76 and 344+/-75, respectively, in the aorta, 284+/-74 and 331+/-71 in the right renal artery, and 285+/-72 and 329+/-73 in the left renal artery. The mean enhancement, image quality, and branch orders visualized were rated better in group B than in group A (P<.01). The accuracies for correctly identifying renal arteries and veins, respectively, were 91% and 95% for group A and 96% and 96% for group B. CONCLUSION Renal donor CT angiography with a contrast medium of 370 mg of iodine per milliliter provides greater enhancement and image quality compared with a contrast medium of 300 mg of iodine per milliliter. The diagnostic accuracies were similar.
Collapse
Affiliation(s)
- Matthew M Rau
- Department of Radiology, Division of Abdominal Imaging and Interventional Radiology, Massachusetts General Hospital, White 270, 55 Fruit St, Boston, MA 02114, USA
| | | | | | | | | | | |
Collapse
|
37
|
Laghi A. Multidetector CT (64 Slices) of the liver: examination techniques. Eur Radiol 2006; 17:675-83. [PMID: 17008988 DOI: 10.1007/s00330-006-0405-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 05/29/2006] [Accepted: 07/14/2006] [Indexed: 10/24/2022]
Abstract
Sixty-four-row MDCT, although developed primarily for cardiac imaging, has the potential to have a great impact on liver imaging as well. Liver-imaging protocols with sub-millimeter collimation improve longitudinal spatial resolution, making the acquired dataset a real isotropic volume perfectly designed for optimal three-dimensional rendering and accurate organ and lesion volumetry. The 64-row detector array offers a wide volumetric coverage (up to 40 mm), suitable not only for shortening scanning time and improving spatial resolution, but also for including a large volume per single rotation, particularly useful for accurate CT perfusion studies. In order to take full benefit from the enormous performance offered by new 64-row MDCT scanners, imaging protocols need to be redesigned. Due to the extremely short scanning window, contrast agent injection should be performed at high flow rate and followed by saline bolus chaser; the use of highly concentrated contrast media might be useful. Timing should be accurately calculated either by a test bolus or, better, by using an automatic bolus-detection technique. Radiation exposure is kept under control, using automatic device-modulating dose delivery according to the patient's anatomy. Finally, the evaluation of acquired volumetric datasets needs the extensive use of a dedicated workstation, with software with sophisticated rendering capabilities.
Collapse
Affiliation(s)
- Andrea Laghi
- Department of Radiological Sciences, University of Rome "La Sapienza", Polo Pontino-ICOT, Latina, Italy.
| |
Collapse
|
38
|
Setty BN, Sahani DV, Ouellette-Piazzo K, Hahn PF, Shepard JAO. Comparison of Enhancement, Image Quality, Cost, and Adverse Reactions Using 2 Different Contrast Medium Concentrations for Routine Chest CT on 16-Slice MDCT. J Comput Assist Tomogr 2006; 30:818-22. [PMID: 16954936 DOI: 10.1097/01.rct.0000229999.30897.3b] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the degree of enhancement and image quality of chest computed tomographic (CT) examinations on 16-slice multidetector CT using low-concentration [300 milligrams of iodine per milliliter (mg I/mL)] and high-concentration (370 mg I/mL) contrast media; to assess the impact on cost and adverse reactions of the use of high-iodine concentration contrast medium. MATERIALS AND METHODS A total of 100 patients scheduled for routine chest CT examinations were administered nonionic contrast medium of 2 strengths: low-iodine concentration contrast medium (300 mg I/mL) [group A: n = 50; male-female ratio, 28:22; mean age, 58.4 years] and high-iodine concentration contrast medium (370 mg I/mL) (group B: n = 50; male-female ratio, 18:32; mean age, 57.6 years) with a constant amount of iodine (400 mg) injected per kilogram of body weight. Contrast media were injected using a dual injector at 2.5 mL/s followed by a 30-mL saline at 2.5 mL/s. The degree of enhancement was quantified by measuring Hounsfield unit values in different arteries and veins and was also rated on a 5-point scale for qualitative assessment. We also evaluated perivenous contrast-related artifacts. The data were compared using Mann-Whitney U test for both qualitative and quantitative enhancement ratings. A value of less than 0.05 was considered statistically significant. The value was adjusted using Bonferroni correction for statistical significance when multiple comparisons were performed. The difference in cost and the incidence of adverse reactions in both groups were calculated. RESULTS The mean enhancement values in group B were significantly greater (P < 0.05) than those in group A. The mean Hounsfield units and standard deviation in groups A and B were aorta = 153 +/- 4, 216 +/- 20; pulmonary artery = 147 +/- 10, 208 +/- 20; superior vena cava = 155 +/- 27, 299 +/- 72; and pulmonary vein = 134 +/- 10, 215 +/- 30, respectively. The mean enhancement on a 5-point scale was greater in group B (4.2) than in group A (3.3) (P < 0.01). No significant difference between groups in perivenous artifacts was seen. Up to 5.5% savings in cost resulted from the use of a higher concentration of iodine, with no increase in adverse reactions. CONCLUSIONS Use of higher-concentration contrast media provides a higher degree of contrast enhancement and image quality for a routine chest CT on a 16-slice multidetector CT. It also contributes to considerable cost savings with no increased risk of adverse reactions compared with low-concentration contrast media.
Collapse
Affiliation(s)
- Bindu N Setty
- Division of Abdominal Imaging and Interventional Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | | | | | |
Collapse
|
39
|
Abstract
Lower-extremity computed tomographic (CT) angiography (ie, peripheral CT angiography) is increasingly used to evaluate patients with peripheral arterial disease. It is therefore increasingly important for all vascular specialists to become familiar with the strengths and limitations of this new technique. The aims of this review are to explain the principles of scanning and injection technique for a wide range of CT scanners, to explain and illustrate the properties of current image postprocessing tools for effective visualization and treatment planning, and to provide an overview of current clinical applications of peripheral CT angiography.
Collapse
Affiliation(s)
- Dominik Fleischmann
- Cardiovascular Imaging Section, Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, S-072, Stanford, California 94305-5105, USA.
| | | | | |
Collapse
|
40
|
Holmquist F, Nyman U. Eighty-peak kilovoltage 16-channel multidetector computed tomography and reduced contrast-medium doses tailored to body weight to diagnose pulmonary embolism in azotaemic patients. Eur Radiol 2006; 16:1165-76. [PMID: 16447047 DOI: 10.1007/s00330-005-0117-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 11/07/2005] [Accepted: 11/24/2005] [Indexed: 11/24/2022]
Abstract
The aim of this study was to assess the feasibility of minimising contrast-medium (CM) doses using 80-peak kilovoltage (kVp) 16-channel multidetector computed tomography (MDCT) with CM dose tailored to body weight, when diagnosing pulmonary embolism (PE) in azotaemic patients. Twenty-nine patients (68-93 years; 38-79 kg) with an estimated glomerular filtration rate of 12-49 ml/min underwent 80 kVp MDCT at a median dose of 200 mg iodine (I)/kg and 15 s injection time. Pulmonary artery (PA) enhancement where compared with our own reference material using 320 mg I/kg at 120 kVp and with reported figures in the literature at 120-140 kVp and a 42 g iodine CM dose. Median (1st and 3rd quartiles) values regarding CM dose were 12.2 (9.9-12.8) g iodine; density of left main and lower lobe segmental PA 339 (275-395) Hounsfield units (HU) and 354 (321-442) HU, respectively. Those enhancement values were similar to those obtained from the reference population at 120 kVp and those reported in the literature at 120-140 kVp. One patient had a transient increase in plasma creatinine. Three months' follow-up revealed deep venous thrombosis among 1/18 patients with negative results from computed tomography (CT). We conclude that 80 kVp 16-channel MDCT to diagnose PE in azotaemic patients may be performed with markedly reduced CM doses, implying a lesser risk for CM-induced nephropathy.
Collapse
Affiliation(s)
- Fredrik Holmquist
- Department of Radiology, Malmö University Hospital, Lund University, 205 02 Malmö, Sweden.
| | | |
Collapse
|
41
|
Hellinger JC. Evaluating mesenteric ischemia with multidetector-row CT angiography. Tech Vasc Interv Radiol 2005; 7:160-6. [PMID: 16015562 DOI: 10.1053/j.tvir.2005.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Multidetector-row computed tomographic (MDCT) angiography is an established non-invasive imaging modality to evaluate the mesenteric vasculature. It has an important role in diagnostic algorithms for assessment of suspected acute and chronic mesenteric ischemia. Clinical success for synchronizing a MDCT volumetric acquisition with a bolus of contrast medium and also for depicting vascular pathology with high accuracy relies on implementing several key principles. This can be more challenging with advanced generation MDCT scanners. This article reviews the technical principles fundamental to evaluating the mesenteric vasculature with MDCT angiography. An overview of clinical application is also presented.
Collapse
Affiliation(s)
- Jeffrey C Hellinger
- Department of Radiology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
| |
Collapse
|
42
|
Hänninen EL, Denecke T, Stelter L, Pech M, Podrabsky P, Pratschke J, Ricke J, Schindler R, Neuhaus P, Felix R, Tullius SG, Tullius SG. Preoperative evaluation of living kidney donors using multirow detector computed tomography: comparison with digital subtraction angiography and intraoperative findings. Transpl Int 2005; 18:1134-41. [PMID: 16162099 DOI: 10.1111/j.1432-2277.2005.00196.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To assess the accuracy of multirow detector computed tomography (MDCT) for the evaluation of renal anatomy for preoperative donor assessment in living related kidney transplantation. MDCT-scans (4- and 16-slice-CT) of 51 consecutive living kidney donors (age, 51.6 +/- 9.7 years; range, 28-68 years) were analysed by three blinded observers and compared with digital subtraction angiography (DSA) and surgery. Contrast-enhanced MDCT was performed with 1 mm slice thickness reconstruction interval during arterial and venous phases. Supernumerary renal arteries, veins, early branching of vessels and abnormalities of the ureters were documented. The overall accuracy of computed tomography angiography (CTA) for detection and classification of surgically relevant arterial variants was 97% (99/102). The interpretation of 16-channel MDCT images was correct in all cases (accuracy, 100%), while the four-channel CTA had three incorrect results regarding the differentiation of early branching vessels from double renal arteries (accuracy, 93%). The overall accuracy of DSA was 91%. Renal vein abnormalities were correctly diagnosed with MDCT in 100% compared with 89% correct findings with DSA. There were three kidneys with incomplete ureter duplication, detected both with MDCT and DSA. MDCT demonstrated superior accuracy compared with non-selective DSA for the preoperative assessment of renal anatomy in living kidney donors; and for the distinction of supernumerary arteries versus early branching patterns, 16-channel CTA data were better than those of the four-channel system.
Collapse
Affiliation(s)
- Enrique Lopez Hänninen
- Department of Radiology, Charité Medical University Center, Campus Virchow Clinic, Augustenburger Platz 1, D-13353 Berlin, Germany.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Rand T, Basile A, Cejna M, Fleischmann D, Funovics M, Gschwendtner M, Haumer M, Von Katzler I, Kettenbach J, Lomoschitz F, Luft C, Minar E, Schneider B, Schoder M, Lammer J. PTA Versus Carbofilm-Coated Stents in Infrapopliteal Arteries: Pilot Study. Cardiovasc Intervent Radiol 2005; 29:29-38. [PMID: 16252079 DOI: 10.1007/s00270-005-0276-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study. METHODS Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47-80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan-Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions. RESULTS The inter-reader agreement was high (kappa = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05). CONCLUSION Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.
Collapse
Affiliation(s)
- T Rand
- Department of Angiography and Interventional Radiology, University of Vienna, Waehringer Guertel 18-20, 1090, Austria.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Abdelmoumene A, Chevallier P, Chalaron M, Schneider F, Verdun FR, Frascarolo P, Meuli R, Schnyder P, Denys A. Detection of liver metastases under 2 cm: comparison of different acquisition protocols in four row multidetector-CT (MDCT). Eur Radiol 2005; 15:1881-7. [PMID: 15868125 DOI: 10.1007/s00330-005-2741-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Revised: 02/21/2005] [Accepted: 03/02/2005] [Indexed: 12/27/2022]
Abstract
This study compared different acquisition protocols performance to detect small liver metastases (<2 cm). Thirty consecutive patients with histologically proven hepatic metastases were explored by MDCT at the liver equilibrium phase by four successive acquisitions. We compared the following protocols (1-4): 5/30/1.5 (section thickness/table speed/pitch); 5/15/0.75; 5/11.25/0.75; and 2.5/15/1.5 with the same X-ray dose. The gold standard was based on patient radiological follow-up. Evolutive lesions were considered as true positive (TP). The described lesions, not found on the follow-up exams despite tumoral progression, were considered as false positive (FP). Stable lesions could not be considered as metastasis and were eliminated. One hundred and seventy-six lesions were detected: 61 TP and 91 FP. Twenty-four lesions were eliminated. The mean kappa values for protocols 1, 2, 3 and 4 were, respectively, 0.43, 0.68, 0.73 and 0.51 (0.61-0.80: substantial agreement) and the mean areas under the ROC curve were, respectively, 0.76, 0.87, 0.86 and 0.80. The results of protocols 2 and 3 were significantly superior to those of protocols 1 and 4. MDCT protocols using thin sections or an increased table speed are less efficient in detecting small metastases.
Collapse
Affiliation(s)
- Amina Abdelmoumene
- Department of Diagnostic and Interventional Radiology, University Hospital Centre (CHUV), 1011 Lausanne, Switzerland.
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Bahner ML, Bengel A, Brix G, Zuna I, Kauczor HU, Delorme S. Improved Vascular Opacification in Cerebral Computed Tomography Angiography With 80 kVp. Invest Radiol 2005; 40:229-34. [PMID: 15770141 DOI: 10.1097/01.rli.0000155281.32319.52] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE We sought to intraindividually compare computed tomography angiographies (CTAs) acquired at 80 kVp and 120 kVp with respect to vessel contrast, noise level, and radiation dose. MATERIAL AND METHODS CTA was performed on a single-slice CT scanner using tube voltages of 80 kVp and 120 kVp in 29 patients with arteriovenous malformations. Mean Hounsfield Units (HU) were evaluated for different vessels and brain parenchyma. To determine contrast-to-noise ratios (CNRs), noise levels were estimated from phantom measurements. RESULTS The calculated effective dose to male/female patients was 0.4/0.5 mSv for 80 kVp and 0.7/0.8 mSv for 120 kVp. CT density in blood vessels was between 297 and 458 HU for 80 kVp and 152 and 229 HU for 120 kVp (P<0.0001). Despite an increased noise level in the low-voltage images, the CNR was 26-59% higher at 80 kVp than at 120 kVp (P<0.05). CONCLUSION The use of a reduced tube potential leads to improved CNR in CTA of the cerebral vasculature and a markedly reduced radiation exposure to patients.
Collapse
Affiliation(s)
- Malte L Bahner
- Department of Radiology (E010), Deutsches Krebsforschungs-zentrum, Heidelberg, Germany
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
CT angiography is now an accepted application of contemporary multidetector row CT. Faster scanning, thinner slices, and improvement in intravenous contrast enhancement are benefits that have offered unique opportunities for pediatric thoracic angiographic evaluation, and often obviate routine angiography. Pediatric CT angiography can be challenging but adherence to a relatively straightforward step-by-step method, emphasizing patient preparation and technical familiarity, can result in excellent examinations even in the smallest infants and most complex clinical scenarios.
Collapse
Affiliation(s)
- Donald P Frush
- Division of Pediatric Radiology, Department of Radiology, Duke University Health System, 1905 McGovern-Davison Children's Health Center, Box 3808, Erwin Road, Durham, NC 27710, USA.
| |
Collapse
|
47
|
Hellinger JC. Endovascular Repair of Thoracic and Abdominal Aortic Aneurysms: Pre- and Postprocedural Imaging. Tech Vasc Interv Radiol 2005; 8:2-15. [PMID: 16098932 DOI: 10.1053/j.tvir.2005.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endovascular repair of thoracic and abdominal aortic aneurysms is a safe alternative to conventional open surgical repair. Clinical success, however, is highly dependent on patient selection. Diagnostic vascular imaging has an essential role for this selection process. Following endovascular aneurysm repair (EVAR), patients require long-term surveillance and again vascular imaging serves an integral function. This article reviews EVAR selection criteria and post-EVAR assessment and then discusses the imaging modalities used to evaluate these patients, namely multi-detector-row computed tomographic angiography, magnetic resonance imaging/angiography, duplex ultrasonography, and catheter angiography.
Collapse
Affiliation(s)
- Jeffrey C Hellinger
- Department of Radiology, Stanford University Medical Center, Stanford, CA 94305, USA.
| |
Collapse
|
48
|
Sandstede JJW, Kaupert C, Roth A, Jenett M, Harz C, Hahn D. Comparison of different iodine concentrations for multidetector row computed tomography angiography of segmental renal arteries. Eur Radiol 2005; 15:1211-4. [PMID: 15678319 DOI: 10.1007/s00330-005-2677-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 12/28/2004] [Accepted: 01/11/2005] [Indexed: 11/28/2022]
Abstract
The aims of this study were (1) to assess the diagnostic performance of multidetector row computed tomography angiography (CTA) on imaging of renal artery branches and (2) to investigate the effect of different iodine concentrations at constant total iodine load and either constant injection rates or constant iodine administration rates. A number of 120 consecutive patients (71+/-6 years of age) underwent CTA of renal arteries (collimation 4 x 1 mm) using the nonionic contrast medium iopromide, and were divided into six equal groups: 1: 150 ml, 240 mg/ml at 4 ml/s; 2: 120 ml, 300 mg/ml at 4 ml/s; 3: 97.3 ml, 370 mg/ml at 4 ml/s; 4: 150 ml, 240 mg/ml at 5 ml/s; 5: 120 ml, 300 mg/ml, 60 ml at 6 ml/s, 60 ml at 3 ml/s; 6: 97.3 ml, 370 mg/ml at 3.3 ml/s. The image quality of the main renal arteries (n=240) and their first-order to fourth-order branches was scored as 0 for no visualization, 1 for only visualization, and 2 for diagnostic. All main renal arteries were diagnostic. First-order branches had score 2 in 38/40, 40/40, 37/40, 38/40, 39/40, and 40/40 patients for groups 1-6, respectively (p=0.34). Second-order branches were imaged best in group 2 (p<0.002)). Third-order branches had score 2 in only 1/40, 5/40, 1/40, 2/40, 0/40, and 2/40 renal arteries. Fourth-order branches were not imaged diagnostically. At a constant total iodine load, the main renal arteries and their first-order branches achieved diagnostic image quality at all iodine concentrations in four-channel multidetector row CTA for the protocols tested. Second-order renal artery branches were imaged best at 120 ml contrast medium with an iodine concentration of 300 mg/ml at 4 ml/s.
Collapse
|
49
|
Frush DP, Herlong JR. Pediatric thoracic CT angiography. Pediatr Radiol 2005; 35:11-25. [PMID: 15565342 DOI: 10.1007/s00247-004-1348-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2004] [Revised: 08/26/2004] [Accepted: 08/27/2004] [Indexed: 11/25/2022]
Abstract
One of the principal benefits of contemporary multidetector row computed tomography (MDCT) has been the ability to obtain high-quality data sets for evaluation of the cardiovascular system. The benefits of the greater number of detector rows and submillimeter image thicknesses were quickly recognized and are especially advantageous in children. For example, since imaging is performed so quickly, issues with motion are minimized. This is a substantial benefit of CTA compared with MR imaging, the traditional noninvasive cross sectional modality for pediatric cardiovascular imaging. This, together with faster and more powerful computers, including improved transfer and storage capabilities, offers improved depiction of the heart, great vessels, other vasculature, and adjacent intrathoracic structures in a fashion that is well accepted by clinical colleagues. In order to be successful, however, one must have an understanding of the technology and often unique technical considerations in infants and children. With this familiarity, excellent cardiovascular examinations can be performed even in the most challenging case.
Collapse
Affiliation(s)
- Donald P Frush
- Division of Pediatric Radiology, 1905 McGovern-Davison Children's Health Center, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
| | | |
Collapse
|
50
|
Suzuki H, Oshima H, Shiraki N, Ikeya C, Shibamoto Y. Comparison of two contrast materials with different iodine concentrations in enhancing the density of the the aorta, portal vein and liver at multi-detector row CT: a randomized study. Eur Radiol 2004; 14:2099-104. [PMID: 15309493 DOI: 10.1007/s00330-004-2439-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Revised: 07/11/2004] [Accepted: 07/15/2004] [Indexed: 10/26/2022]
Abstract
This work investigates differences in contrast enhancement of the aorta, portal vein and liver by two different concentrations of contrast materials using an automatic bolus tracking technique. Seventy patients were assigned randomly into one of two groups. Contrast materials with iodine concentrations of 300 and 370 mg/ml were administered to patients in groups A and B, respectively. The total iodine load (600 mg/kg) and injection time (30 s) were identical. Differences in the increase of the Hounsfield unit of the aorta, portal vein and liver between the two groups were examined by t-test. There were no significant differences between the two groups in any of the contrast enhancements of the aorta, portal vein and liver parenchyma at all phases, except for enhancement of the portal vein at the late arterial phase. Females showed better contrast enhancement of the aorta and portal vein than males. With the same iodine dose and injection time, the concentration of contrast materials did not seem to influence the efficacy of contrast enhancement of the aorta, portal vein and liver, except for the portal vein at the late arterial phase. Planning of protocols for contrast media injection may be made irrespective of the iodine concentrations.
Collapse
Affiliation(s)
- Hiromasa Suzuki
- Department of Radiology, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, 467-8601 Nagoya, Japan.
| | | | | | | | | |
Collapse
|