1
|
Chandrasekharan R, Kulkarni CB, Pullara SK, Moorthy S. Does Contrast Dose Based in Lean body Weight Allow Lesser Volumes on High BMI Patients for CT Angiography? J Clin Imaging Sci 2021; 11:38. [PMID: 34345528 PMCID: PMC8326097 DOI: 10.25259/jcis_97_2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 06/17/2021] [Indexed: 11/22/2022] Open
Abstract
Objectives: The objective was to evaluate whether contrast dose based on lean body weight (LBW) protocol has the potential to reduce contrast volume in patients with high basal metabolic index (BMI) compared to total body weight (TBW)-based protocols. Material and Methods: The Institutional Review Board approval was obtained for this prospective study. Initially, a pilot study with a sample size of 150 patients was conducted to estimate the average fat fraction in our population. Then, CT angiography (CTA) for the thoracic and abdominal aorta was performed using a 256-multidetector computed tomography scanner in 117 patients who were undergoing screening for aortic aneurysm and vascular assessment of prospective transplant donors. The patients were divided into two groups: A TBW group (n = 60) and LBW group (n = 57). Lean body weight (LBW) was estimated from the patient weight, height, and gender using Hume’s equation. The TBW group received 1.2 ml/kg contrast dose and the LBW group received 1.6 ml/kg contrast dose to achieve approximately equal iodine dose in both groups. Differences in the degree of aortic enhancement between the estimated LBW and TBW group were evaluated. In higher BMI patients (>25), the mean aortic enhancement (MAEnh) and the contrast volume delivered between the LBW and TBW group were compared. Results: Mean aortic enhancement (MAEnh) 422.45 (±74.5) Hounsfield unit (HU) in the TBW group and 432.67 (±69.4) HU in the LBW group showed no statistical difference (P = 0.439). In population with BMI >25, the contrast delivered in LBW protocol patients was significantly less (P = 0.00) compared to TBW protocol patients, with no significant difference in the MAEnh between the groups (P = 0.479). Conclusion: CTA using a LBW protocol helps to significantly reduce the volume of contrast delivered, especially in patients with BMI >25 compared to TBW protocol, without compromising the aortic enhancement.
Collapse
Affiliation(s)
- Rajsekar Chandrasekharan
- Department of Radiology, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - Chinmay Bhimaji Kulkarni
- Department of Radiology, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | | | - Srikanth Moorthy
- Department of Radiology, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| |
Collapse
|
2
|
Obmann MM, Gehweiler J, Schindera ST, Janetzki J, Boll DT, Benz MR. Clinical evaluation of a novel multibolus contrast agent injection protocol for thoraco-abdominal CT angiography: Assessment of homogeneity of arterial contrast enhancement. Eur J Radiol 2020; 126:108957. [PMID: 32244065 DOI: 10.1016/j.ejrad.2020.108957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the in vivo feasibility of a multibolus contrast agent (CA) injection protocol with a reduced CA volume for thoraco-abdominal CT angiography (CTA) and to compare it to a single-bolus CA injection protocol. METHOD 63 patients who underwent CTA with the multibolus protocol (60 ml CA) were divided in two groups either without (group 1, n = 48) or with (group 2, n = 15) aortic dissection. The aortic contrast enhancement was measured in group 1 using manual ROI analysis (10 segments), as well as semi-automated linear attenuation profiles. A subgroup (n = 18) of group 1, who also underwent imaging with the single-bolus protocol (94 ml CA), was used to compare both protocols. In group 2, differences in attenuation of the true and the false lumen for both the single- and the multibolus protocol were assessed with ROI attenuation measurements in both lumina. Comparisons were made using Wilcoxon test. RESULTS Average attenuation was above 200 HU for 98 % of cases using the multibolus protocol. There was superior contrast homogeneity for the multibolus protocol with a lower standard deviation of attenuation values along the length of the scan (p = 0.003), while average attenuation was higher for the single-bolus protocol (p = 0.002). Prolonged enhancement plateau lead to a more uniform opacification of the true and the false lumen in patients with aortic dissection using the multibolus protocol (p = 0.012). CONCLUSIONS The multibolus protocol in thoraco-abdominal CTA is feasible in patients. It shows consistently high arterial enhancement with superior contrast homogeneity compared to a single-bolus protocol in patients with and without aortic dissection.
Collapse
Affiliation(s)
- Markus M Obmann
- Clinic of Radiology and Nuclear Medicine, University Hospital of Basel, Switzerland.
| | - Julian Gehweiler
- Clinic of Radiology and Nuclear Medicine, University Hospital of Basel, Switzerland
| | | | - Julia Janetzki
- Clinic of Radiology and Nuclear Medicine, University Hospital of Basel, Switzerland
| | - Daniel T Boll
- Clinic of Radiology and Nuclear Medicine, University Hospital of Basel, Switzerland
| | - Matthias R Benz
- Clinic of Radiology and Nuclear Medicine, University Hospital of Basel, Switzerland.
| |
Collapse
|
3
|
Low-tube-voltage CT assessment of Adamkiewicz artery: Precise comparison between 100-kVp- and 120-kVp protocols. Eur J Radiol 2019; 111:56-61. [PMID: 30691665 DOI: 10.1016/j.ejrad.2018.12.014] [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: 09/23/2018] [Revised: 12/05/2018] [Accepted: 12/13/2018] [Indexed: 11/19/2022]
Abstract
PURPOSE Preoperative identification of Adamkiewicz artery (AKA) for preventing postoperative spinal cord ischemia is still challenging because of its small diameter. Low-tube-voltage technique might improve the delineation of AKA due to its higher contrast enhancement and contrast-to-noise ratio (CNR). Our purpose was to evaluate the usefulness of low-tube-voltage CTA in visualization of AKA compared with the conventional voltage protocol on the condition with the same imaging parameters aside from tube voltage. METHODS Eighty-three patients undergoing CTA for the evaluation of aorta were retrospectively included. All CTA was performed with 320-detector-row CT with the tube voltage of either 100-kVp (41 patients) or 120-kVp (42 patients). The CNR, CT value of aorta and objective image noise were assessed. Visualization of AKA was evaluated based on the continuity from aorta using the four-grade score by two independent reviewers. The estimated radiation dose (volumetric CT dose index) was also compared. RESULTS The 100-kVp group showed significantly higher CNR and CT value than 120-kVp protocol (P = 0.010 and < 0.001, respectively). The visual score was also significantly higher in 100-kVp group than in 120-kVp group (2.73 ± 0.98 and 2.02 ± 1.00, respectively; P = 0.002). There was no significant difference on objective image noise and radiation dose between the groups (P = 0.24 and 0.72, respectively). CONCLUSION CTA with low-tube-voltage was significantly more sensitive for AKA visualization than conventional voltage protocol.
Collapse
|
4
|
Utility of Cardiac Computed Tomography in Patients with Left Ventricular Assist Devices. CURRENT CARDIOVASCULAR IMAGING REPORTS 2018. [DOI: 10.1007/s12410-018-9466-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
5
|
Pei Y, Li F, Shen H, Long X, Liu H, Wang X, Liu J, Li W. Optimal Blood Suppression Inversion Time Based on Breathing Rates and Heart Rates to Improve Renal Artery Visibility in Spatial Labeling with Multiple Inversion Pulses: A Preliminary Study. Korean J Radiol 2016; 17:69-78. [PMID: 26798218 PMCID: PMC4720814 DOI: 10.3348/kjr.2016.17.1.69] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 10/20/2015] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine whether an optimal blood suppression inversion time (BSP TI) can boost arterial visibility and whether the optimal BSP TI is related to breathing rate (BR) and heart rate (HR) for hypertension subjects in spatial labeling with multiple inversion pulses (SLEEK). MATERIALS AND METHODS This prospective study included 10 volunteers and 93 consecutive hypertension patients who had undergone SLEEK at 1.5T MRI system. Firstly, suitable BSP TIs for displaying clearly renal artery were determined in 10 volunteers. Secondly, non-contrast enhanced magnetic resonance angiography with the suitable BSP TIs were performed on those hypertension patients. Then, renal artery was evaluated and an optimal BSP TI to increase arterial visibility was determined for each patient. Patients' BRs and HRs were recorded and their relationships with the optimal BSP TI were analyzed. RESULTS The optimal BSP TI was negatively correlated with BR (r1 = -0.536, P1 < 0.001; and r2 = -0.535, P2 < 0.001) and HR (r1 = -0.432, P1 = 0.001; and r2 = -0.419, P2 = 0.001) for 2 readers (κ = 0.93). For improving renal arterial visibility, BSP TI = 800 ms could be applied as the optimal BSP TI when the 95% confidence interval were 17-19/min (BR1) and 74-82 bpm (HR1) for reader#1 and 17-19/min (BR2) and 74-83 bpm (HR2) for reader#2; BSP TI = 1100 ms while 14-15/min (BR1, 2) and 71-76 bpm (HR1, 2) for both readers; and BSP TI = 1400 ms when 13-16/min (BR1) and 63-68 bpm (HR1) for reader#1 and 14-15/min (BR2) and 64-70 bpm (HR2) for reader#2. CONCLUSION In SLEEK, BSP TI is affected by patients' BRs and HRs. Adopting the optimal BSP TI based on BR and HR can improve the renal arterial visibility and consequently the working efficiency.
Collapse
Affiliation(s)
- Yigang Pei
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Fang Li
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Hao Shen
- GE Healthcare, Waukesha, WI 53188, USA
| | - Xueying Long
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Hui Liu
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Xiaoyi Wang
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Jinkang Liu
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Wenzheng Li
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| |
Collapse
|
6
|
Lin YH, Huang SM, Huang CY, Tu YN, Liu SH, Huang TC. Quantitative analysis of respiration-related movement for abdominal artery in multiphase hepatic CT. PLoS One 2014; 9:e114222. [PMID: 25536144 PMCID: PMC4275208 DOI: 10.1371/journal.pone.0114222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/04/2014] [Indexed: 11/21/2022] Open
Abstract
Objectives Respiration-induced motion in the liver causes potential errors on the measurement of contrast medium in abdominal artery from multiphase hepatic CT scans. In this study, we investigated the use of hepatic CT images to quantitatively estimate the abdominal artery motion due to respiration by optical flow method. Materials and Methods A total of 132 consecutive patients were included in our patient cohort. We apply the optical flow method to compute the motion of the abdominal artery due to respiration. Results The minimum and maximum displacements of the abdominal artery motion were 0.02 and 30.87 mm by manual delineation, 0.03 and 40.75 mm calculated by optical flow method, respectively. Both high consistency and correlation between the present method and the physicians’ manual delineations were acquired with the regression equation of movement, y = 0.81x+0.25, r = 0.95, p<0.001. Conclusion We estimated the motion of abdominal artery due to respiration using the optical flow method in multiphase hepatic CT scans and the motion estimations were validated with the visualization of physicians. The quantitative analysis of respiration-related movement of abdominal artery could be used for motion correction in the measurement of contrast medium passing though abdominal artery in multiphase CT liver scans.
Collapse
Affiliation(s)
- Yang-Hsien Lin
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan
| | - Shih-Min Huang
- Department of Radiology, China Medical University Hospital, Taichung City, Taiwan
| | - Chin-Yi Huang
- Department of Diagnostic Radiology, Peng Hu Hospital, Ministry of Health and Welfare, Peng Hu City, Taiwan
| | - Yun-Niang Tu
- Department of Diagnostic Radiology, Peng Hu Hospital, Ministry of Health and Welfare, Peng Hu City, Taiwan
| | - Shing-Hong Liu
- Department of Computer Science and Information Engineering, Chaoyang University of Technology, Taichung, Taiwan
| | - Tzung-Chi Huang
- Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan
- Department of Biomedical Informatics, Asia University, Taichung City, Taiwan
- * E-mail:
| |
Collapse
|
7
|
Evaluation of Renal Artery in Hypertensive Patients by Unenhanced MR Angiography Using Spatial Labeling With Multiple Inversion Pulses Sequence and by CT Angiography. AJR Am J Roentgenol 2012; 199:1142-8. [PMID: 23096191 DOI: 10.2214/ajr.11.7263] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
8
|
Marin D, Nelson RC, Guerrisi A, Barnhart H, Schindera ST, Passariello R, Catalano C. 64-section multidetector CT of the upper abdomen: optimization of a saline chaser injection protocol for improved vascular and parenchymal contrast enhancement. Eur Radiol 2011; 21:1938-47. [DOI: 10.1007/s00330-011-2139-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/19/2011] [Accepted: 04/04/2011] [Indexed: 11/30/2022]
|
9
|
Keeling AN, Farrelly C, Carr JC, Yaghmai V. Technical considerations for lower limb multidetector computed tomographic angiography. Vasc Med 2010; 16:131-43. [PMID: 21138985 DOI: 10.1177/1358863x10388347] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Multidetector computed tomography (MDCT) enables imaging of the entire arterial tree non-invasively. Optimal technical considerations for performing MDCT angiography (MDCTA) are essential for accurate diagnosis and atherosclerotic disease stratification. This review article focuses on the various technical aspects necessary for peripheral computed tomographic angiography (CTA) acquisition. Common clinical indications for peripheral MDCTA and the latest scan protocols are described. The essential issue of radiation dose reduction is discussed, along with methods of optimal contrast bolus detection and delivery. Post-processing techniques are also presented. Previously, digital subtraction angiography was the only established reliable imaging technique to quantify atherosclerotic disease load; however, MDCTA may now challenge this old gold standard, along with other non-invasive techniques such as magnetic resonance angiography (MRA).
Collapse
Affiliation(s)
- Aoife N Keeling
- Department of Radiology, Division of Cardiovascular Imaging, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| | | | | | | |
Collapse
|
10
|
Schindera ST, Tock I, Marin D, Nelson RC, Raupach R, Hagemeister M, von Allmen G, Vock P, Szucs-Farkas Z. Effect of Beam Hardening on Arterial Enhancement in Thoracoabdominal CT Angiography with Increasing Patient Size: An in Vitro and in Vivo Study. Radiology 2010; 256:528-35. [DOI: 10.1148/radiol.10092086] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
11
|
Bae KT. Intravenous contrast medium administration and scan timing at CT: considerations and approaches. Radiology 2010; 256:32-61. [PMID: 20574084 DOI: 10.1148/radiol.10090908] [Citation(s) in RCA: 646] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The continuing advances in computed tomographic (CT) technology in the past decades have provided ongoing opportunities to improve CT image quality and clinical practice and discover new clinical CT imaging applications. New CT technology, however, has introduced new challenges in clinical radiology practice. One of the challenges is with intravenous contrast medium administration and scan timing. In this article, contrast medium pharmacokinetics and patient, contrast medium, and CT scanning factors associated with contrast enhancement and scan timing are presented and discussed. Published data from clinical studies of contrast medium and physiology are reviewed and interpreted. Computer simulation data are analyzed to provide an in-depth analysis of various factors associated with contrast enhancement and scan timing. On the basis of basic principles and analysis of the factors, clinical considerations and modifications to protocol design that are necessary to optimize contrast enhancement for common clinical CT applications are proposed.
Collapse
Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
| |
Collapse
|
12
|
Utsunomiya D, Oda S, Funama Y, Awai K, Nakaura T, Yanaga Y, Hirai T, Yamashita Y. Comparison of standard- and low-tube voltage MDCT angiography in patients with peripheral arterial disease. Eur Radiol 2010; 20:2758-65. [DOI: 10.1007/s00330-010-1841-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 05/04/2010] [Accepted: 05/14/2010] [Indexed: 10/19/2022]
|
13
|
|
14
|
Contrast Material Administration Protocols for 64-MDCT Angiography: Altering Volume and Rate and Use of a Saline Chaser to Better Match the Imaging Window—Physiologic Phantom Study. AJR Am J Roentgenol 2009; 193:1568-75. [DOI: 10.2214/ajr.09.2670] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
15
|
|
16
|
Schindera ST, Nelson RC, Yoshizumi T, Toncheva G, Nguyen G, DeLong DM, Szucs-Farkas Z. Effect of automatic tube current modulation on radiation dose and image quality for low tube voltage multidetector row CT angiography: phantom study. Acad Radiol 2009; 16:997-1002. [PMID: 19409820 DOI: 10.1016/j.acra.2009.02.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 02/24/2009] [Accepted: 02/26/2009] [Indexed: 11/16/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the effect of automatic tube current modulation on radiation dose and image quality for low tube voltage computed tomography (CT) angiography. MATERIALS AND METHODS An anthropomorphic phantom was scanned with a 64-section CT scanner using following tube voltages: 140 kVp (Protocol A), 120 kVp (Protocol B), 100 kVp (Protocol C), and 80 kVp (Protocol D). To achieve similar noise, combined z-axis and xy-axes automatic tube current modulation was applied. Effective dose (ED) for the four tube voltages was assessed. Three plastic vials filled with different concentrations of iodinated solution were placed on the phantom's abdomen to obtain attenuation measurements. The signal-to-noise ratio (SNR) was calculated and a figure of merit (FOM) for each iodinated solution was computed as SNR(2)/ED. RESULTS The ED was kept similar for the four different tube voltages: (A) 5.4 mSv +/- 0.3, (B) 4.1 mSv +/- 0.6, (C) 3.9 mSv +/- 0.5, and (D) 4.2 mSv +/- 0.3 (P > .05). As the tube voltage decreased from 140 to 80 kVp, image noise was maintained (range, 13.8-14.9 HU) (P > .05). SNR increased as the tube voltage decreased, with an overall gain of 119% for the 80-kVp compared to the 140-kVp protocol (P < .05). The FOM results indicated that with a reduction of the tube voltage from 140 to 120, 100, and 80 kVp, at constant SNR, ED was reduced by a factor of 2.1, 3.3, and 5.1, respectively, (P < .001). CONCLUSIONS As tube voltage decreases, automatic tube current modulation for CT angiography yields either a significant increase in image quality at constant radiation dose or a significant decrease in radiation dose at a constant image quality.
Collapse
Affiliation(s)
- Sebastian T Schindera
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, Bern, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
17
|
Takao H, Nojo T, Ohtomo K. Use of a saline chaser in abdominal computed tomography: a systematic review. Clin Imaging 2009; 33:261-6. [DOI: 10.1016/j.clinimag.2008.10.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Accepted: 10/20/2008] [Indexed: 11/28/2022]
|
18
|
Effect of Contrast Injection Protocols with Dose Adjusted to the Estimated Lean Patient Body Weight on Aortic Enhancement at CT Angiography. AJR Am J Roentgenol 2009; 192:1071-8. [DOI: 10.2214/ajr.08.1407] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
19
|
Aortic and hepatic contrast enhancement with abdominal 64-MDCT in pediatric patients: effect of body weight and iodine dose. AJR Am J Roentgenol 2008; 191:1589-94. [PMID: 18941106 DOI: 10.2214/ajr.07.3576] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of our study was to retrospectively evaluate the effect of body weight and iodine dose on aortic and hepatic contrast enhancement in pediatric patients who underwent 64-MDCT of the abdomen and pelvis. MATERIALS AND METHODS Eighty-seven consecutive pediatric patients (50 boys and 37 girls; median age, 12.1 years; age range, 3.8-17.6 years) underwent standard abdominopelvic CT with a 64-MDCT scanner. Contrast medium (350 mg I/mL) was injected using a power injector at 2 mL/s followed by 15-20 mL of saline flush. According to our CT protocol, the volume of administered contrast medium was approximately 1.8 mL/kg of body weight, up to the maximum volume of 80 mL. CT scanning was initiated 60 seconds after the start of the contrast medium injection. CT attenuations of the aorta and liver were measured. For each patient, the injected contrast medium iodine mass per body weight index (g I/kg) (hereafter, iodine mass body index) was calculated. Linear regression analysis was performed between iodine mass body index and aortic and hepatic attenuations. RESULTS A wide range of patient weights (19-82 kg; mean, 48.6 kg [95% CI, 45.3-51.9 kg]) and contrast volumes (30-80 mL; median, 80.0 mL) were observed. The median attenuations were 149.0 HU (141.0-160.0 HU) for the aorta and 113.5 HU (109.5-120.0 HU) for the liver. Moderately high correlations were observed between iodine mass body index and aortic (Spearman's rho [r(s)] = 0.60 [0.45-0.72]; p < 0.001) and hepatic (r(s) = 0.60 [0.42-0.70]; p < 0.001) attenuations. The regression formulae for aortic attenuation (58.4 + 176.3 x iodine mass body index [p < 0.001]) and hepatic attenuation (58.7 + 108.5 x iodine mass body index [p < 0.001]) indicate that 1.5 and 1.8 mL/kg (350 mg I/mL) of contrast media are required to achieve 116 and 127 HU, respectively, of contrast-enhanced attenuation in the liver. CONCLUSION In our study, using abdominal 64-MDCT in pediatric patients, we found that approximately 1.5 mL/kg, or 0.525 g I/kg, yields 116 HU of hepatic attenuation or 50-55 HU of hepatic enhancement.
Collapse
|
20
|
Contrast Injection Protocols for Coronary Computed Tomography Angiography Using a 64-Detector Scanner: Comparison Between Patient Weight-Adjusted- and Fixed Iodine-Dose Protocols. Invest Radiol 2008; 43:512-9. [PMID: 18580334 DOI: 10.1097/rli.0b013e3181727505] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
21
|
Fortuño Andrés JR, Falco i Fages J, Perendreu i Sans J, Branera i Pujol J, Bermúdez Bencerrey P, Bellmunt i Montoya S, Safont i Sala MR. [Multislice CT angiography in the study of aneurysm of the abdominal aorta: comparison of three different volumes of contrast agent]. RADIOLOGIA 2008; 50:225-30. [PMID: 18471387 DOI: 10.1016/s0033-8338(08)71968-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To prospectively and quantitatively compare the use of different volumes of contrast in 16-slice CT angiography for the study of aneurysms of the abdominal aorta before and/or after treatment. MATERIAL AND METHODS From November 2005 to March 2006, we included 63 consecutive patients referred for CT angiography for aneurysm of the abdominal aorta or for post-treatment follow-up. Each patient was randomly assigned to one of three groups: group A was administered 100 mL of contrast agent, group B 80 mL, and group C 60 mL. In all cases, contrast was administered with 40 mL of physiological serum at a rate of 4 ml/s. A 16-detector CT scanner was used. In the last 61 patients, attenuation was measured in different locations using circular ROIs. Hounsfield units were recorded in the first slice (initial contrast), in the last slice (final contrast), at their maximum value, and also at one-second intervals. RESULTS No statistically significant differences in the Hounsfield units recorded in the first slice, in the last slice, or in the maximum values were found between the different groups. Mean values were above 200 in 58 of 61 patients. Weight and body mass index (BMI) were negatively correlated with aortoiliac attenuation. CONCLUSION Using a 16-detector CT scanner enables the volume of contrast for studies of aneurysms of the abdominal aorta to be reduced considerably; however, 60 mL might not be sufficient for patients with high weight or BMI.
Collapse
Affiliation(s)
- J R Fortuño Andrés
- Unidad de Radiología Vascular e intervencionista. Corporación Sanitaria Parc Taulí. Hospital de Sabadell. Barcelona. España.
| | | | | | | | | | | | | |
Collapse
|
22
|
Yang CY, Chen YF, Lee CW, Huang A, Shen Y, Wei C, Liu HM. Multiphase CT angiography versus single-phase CT angiography: comparison of image quality and radiation dose. AJNR Am J Neuroradiol 2008; 29:1288-95. [PMID: 18403555 DOI: 10.3174/ajnr.a1073] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Conventional CT angiography (CTA) is acquired during only a short interval in the arterial phase, which limits its ability to evaluate the cerebral circulation. Our aim was to compare the image quality and radiation dose of conventional single-phase CTA (SP-CTA) with a multiphase CTA (MP-CTA) algorithm reconstructed from a perfusion CT (PCT) dataset. MATERIALS AND METHODS Fifty consecutive patients undergoing head CTA and PCT in 1 examination were enrolled. The PCT dataset was obtained with 40.0-mm-detector coverage, 5.0-mm axial thickness, 80 kilovolt peak (kVp), 180 mA, and 30 mL of contrast medium. MP-CTA was reconstructed from the same PCT dataset with an axial thickness of 0.625 mm by using a new axial reconstruction algorithm. A conventional SP-CTA dataset was obtained with 0.625-mm axial thickness, 120 kVp, 350 mA, and 60 mL of contrast medium. We compared image quality, vascular enhancement, and radiation dose. RESULTS SP-CTA and MP-CTA of 50 patients (male/female ratio, 31/19; mean age, 59.25 years) were analyzed. MP-CTA was significantly better than SP-CTA in vascular enhancement (P = .002), in the absence of venous contamination (P = .006), and was significantly higher in image noise (P < .001). MP-CTA used less contrast medium than SP-CTA and could demonstrate hemodynamic information. The effective dose of MP-CTA was 5.73 mSv, which was equal to that in conventional PCT, and it was 3.57 mSv in SP-CTA. CONCLUSION It is feasible that MP-CTA may provide both CTA and PCT results. Compared with SP-CTA, MP-CTA provides comparable image quality, better vascular enhancement, hemodynamic information, and more noise with less detail visibility with a lower tube voltage. The radiation dose of MP-CTA is higher than that of SP-CTA, but the dose can be reduced by altering the sampling interval.
Collapse
Affiliation(s)
- C-Y Yang
- Department of Medical Imaging, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
23
|
Diehm N, Pena C, Benenati JF, Tsoukas AI, Katzen BT. Adequacy of an early arterial phase low-volume contrast protocol in 64-detector computed tomography angiography for aortoiliac aneurysms. J Vasc Surg 2008; 47:492-8. [DOI: 10.1016/j.jvs.2007.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 11/02/2007] [Accepted: 11/03/2007] [Indexed: 10/22/2022]
|
24
|
Utsunomiya D, Miyazaki M, Nomitsu Y, Komeda Y, Okigawa T, Urata J, Yamashita Y. Clinical Role of Non-Contrast Magnetic Resonance Angiography for Evaluation of Renal Artery Stenosis. Circ J 2008; 72:1627-30. [DOI: 10.1253/circj.cj-08-0005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Mitsue Miyazaki
- Department of Advanced Clinical Research, MR, Toshiba Medical Research Institute
| | - Yohei Nomitsu
- Diagnostic Imaging Center, Saiseikai Kumamoto Hospital
| | - Yosuke Komeda
- Diagnostic Imaging Center, Saiseikai Kumamoto Hospital
| | | | - Joji Urata
- Diagnostic Imaging Center, Saiseikai Kumamoto Hospital
| | - Yasuyuki Yamashita
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University
| |
Collapse
|
25
|
Enhancement Performance of a 64-Slice Triple Rule-Out Protocol vs 16-Slice and 10-Slice Multidetector CT-Angiography Protocols for Evaluation of Aortic and Pulmonary Vasculature. J Comput Assist Tomogr 2007; 31:917-23. [DOI: 10.1097/rct.0b013e318040aded] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
26
|
Lee CH, Goo JM, Bae KT, Lee HJ, Kim KG, Chun EJ, Park CM, Im JG. CTA Contrast Enhancement of the Aorta and Pulmonary Artery. Invest Radiol 2007; 42:486-90. [PMID: 17568270 DOI: 10.1097/rli.0b013e318032a9fe] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the effect of saline chase injected at 2 different rates on computed tomography (CT) angiography. MATERIALS AND METHODS This study was approved by our institutional animal study committee. Three injection protocols were used; contrast injection (24 mL, 0.8 mL/s) without saline chase (protocol A), contrast injection with saline chase injected at the same rate as the contrast medium (protocol B), and contrast injection with saline chase injected at half the rate (0.4 mL/s) of the contrast medium (protocol C). In the 3 dogs used in our study, each of the protocols was applied twice for every dog resulting in a total of 18 sessions of monitoring scans. CT images were acquired every second at the fixed level of the aorta and pulmonary artery (PA). The duration of plateau, plateau deviation, and peak arterial enhancement were computed and compared using the Kruskall-Wallis and Mann-Whitney U test. RESULTS Peak contrast enhancements were significantly more delayed with protocol B than with protocol A in both the PA (B: 48 seconds, A: 30 seconds, P=0.024) and aorta (B: 46 seconds, A: 38 seconds, P=0.024). The duration of enhancement plateau was longer with protocol B than with protocol A in PA (B: 14.8 seconds, A: 9.0 seconds, P=0.002) and in aorta (B: 16.2 seconds, A: 11.6 seconds, P=0.004). Protocol C had the longest duration of plateau in both PA (34.5 seconds, P=0.002) and aorta (33.8 seconds, P=0.004) with uniform plateau enhancement. The peak enhancement values of protocol C, however, were substantially lower than that of protocol A and B in both the PA (A: 262 HU, B: 239 HU, C: 191 HU, P=0.001) and aorta (A: 263 HU, B: 268 HU, C: 210 HU, P=0.001). CONCLUSIONS Saline chase prolongs the duration of plateau and delays peak enhancement of the pulmonary artery and aorta. Saline chase injected at half the rate of contrast medium injection allowed more uniform and prolonged plateau contrast enhancement than other protocols.
Collapse
Affiliation(s)
- Chang Hyun Lee
- Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Jongno-gu, and Seoul National University Hospital, Healthcare Gangnam Center, Gangnam-gu, Seoul, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Kubo S, Tadamura E, Yamamuro M, Kanao S, Kataoka ML, Takahashi M, Kimura T, Kita T, Komeda M, Togashi K. Multidetector-row Computed Tomographic Angiography of Thoracic and Abdominal Aortic Aneurysms. J Comput Assist Tomogr 2007; 31:422-9. [PMID: 17538290 DOI: 10.1097/01.rct.0000237819.64419.d2] [Citation(s) in RCA: 9] [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
OBJECTIVE To compare the quality of multidetector-row computed tomographic angiography in patients with and without aortic aneurysms by 3 different amounts of contrast media (CM). METHODS A total of 115 patients with aortic aneurysms were divided into 3 groups: group A, 100 mL CM; group B, 75 mL CM with 20 mL saline flush (SF); and group C, 50 mL CM with 20 mL SF. Twenty-five patients without aortic aneurysms were also enrolled (group D, 50 mL CM with 20 mL SF). Quantitative and qualitative analyses were performed by measuring attenuation in thoracoabdominal/aortoiliac lumen, aneurysmal lumen, and superior vena cava. RESULTS In group C, attenuation was lower in distal than those in proximal and middle areas (P < 0.05). Contrast enhancement in abdominal aneurysmal lumen was more inhomogeneous in group C (P = 0.003). Visual analysis showed contrast enhancement was more nonuniform in group C (P = 0.004), and perivenous artifacts were more conspicuous in group A (P < 0.0001). CONCLUSIONS Seventy-five milliliters CM followed by 20 mL SF can produce optimal contrast enhancement at systemic multidetector-row computed tomographic angiography in patients with aortic aneurysms.
Collapse
Affiliation(s)
- Shigeto Kubo
- Department of Nuclear Medicine and Diagnostic Imaging, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Nakayama Y, Awai K, Funama Y, Liu D, Nakaura T, Tamura Y, Yamashita Y. Lower tube voltage reduces contrast material and radiation doses on 16-MDCT aortography. AJR Am J Roentgenol 2006; 187:W490-7. [PMID: 17056879 DOI: 10.2214/ajr.05.0471] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The purpose of our study was to compare aortic CT angiography performed at a low tube voltage and reduced dose of contrast material with standard-voltage, standard-contrast-dose CT angiography. SUBJECTS AND METHODS We evaluated 74 patients for aortic disease on MDCT angiography (collimation, 16 x 1.5 mm; beam pitch, 0.9). In 36 patients, we used the standard tube voltage (120 kVp) and a contrast dose of 100 mL (300 mg I/mL) (protocol 1), and in the remaining 38 patients we applied a reduced tube voltage (90 kVp) and a contrast dose of 40 mL (300 mg I/mL) (protocol 2). The patients' weights, CT attenuation of the aorta, visualization of the celiac axis and renal artery, and graininess and streak artifacts on transverse CT scans were evaluated and recorded for each data set. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were also measured. For statistical analysis, we used the two-tailed Student's t test and logistic regression; agreement between measurements recorded independently by two blinded reviewers was assessed using Cohen kappa statistics. RESULTS In both protocols a negative correlation was seen between patient weight and CT attenuation. In three protocol 1 patients weighing more than 70 kg, CT attenuation was less than 200 H. No difference was seen between the two protocols with respect to mean attenuation of the aorta (p = 0.13) or visualization of the celiac axis and renal artery (p = 0.35 and 0.60, respectively). Although the SNR and CNR were significantly higher in protocol 1 than in protocol 2, qualitative evaluation of graininess and streak artifacts showed no statistically significant difference (p = 0.15 and 0.48, respectively). Interobserver agreement for quality assessments was within an acceptable range (kappa = 0.42-0.80). CONCLUSION Low-contrast and low-voltage scans are appropriate for lighter patients (< 70 kg in body weight) with aortic disease. Moreover, this method is particularly valuable for follow-up studies of heavier patients (> 70 kg) with renal dysfunction.
Collapse
Affiliation(s)
- Yoshiharu Nakayama
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
| | | | | | | | | | | | | |
Collapse
|