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Sauer TJ, Abadi E, Segars P, Samei E. Anatomically- and physiologically-informed computational model of hepatic contrast perfusion for virtual imaging trials. Med Phys 2022; 49:2938-2951. [PMID: 35195901 PMCID: PMC9547339 DOI: 10.1002/mp.15562] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 02/02/2022] [Accepted: 02/02/2022] [Indexed: 12/10/2022] Open
Abstract
PURPOSE Virtual (in silico) imaging trials (VITs), involving computerized phantoms and models of the imaging process, provide a modern alternative to clinical imaging trials. VITs are faster, safer, and enable otherwise-impossible investigations. Current phantoms used in VITs are limited in their ability to model functional behavior such as contrast perfusion which is an important determinant of dose and image quality in CT imaging. In our prior work with the XCAT computational phantoms, we determined and modeled inter-organ (organ to organ) intravenous contrast concentration as a function of time from injection. However, intra-organ concentration, heterogeneous distribution within a given organ, was not pursued. We extend our methods in this work to model intra-organ concentration within the XCAT phantom with a specific focus on the liver. METHODS Intra-organ contrast perfusion depends on the organ's vessel network. We modeled the intricate vascular structures of the liver, informed by empirical and theoretical observations of anatomy and physiology. The developed vessel generation algorithm modeled a dual-input-single-output vascular network as a series of bifurcating surfaces to optimally deliver flow within the bounding surface of a given XCAT liver. Using this network, contrast perfusion was simulated within voxelized versions of the phantom by using knowledge of the blood velocities in each vascular structure, vessel diameters and length, and the time since the contrast entered the hepatic artery. The utility of the enhanced phantom was demonstrated through a simulation study with the phantom voxelized prior to CT simulation with the relevant liver vasculature prepared to represent blood and iodinated contrast media. The spatial extent of the blood-contrast mixture was compared to clinical data. RESULTS The vascular structures of the liver were generated with size and orientation which resulted in minimal energy expenditure required to maintain blood flow. Intravenous contrast was simulated as having known concentration and known total volume in the liver as calibrated from time-concentration curves (TCC). Measurements of simulated CT ROIs were found to agree with clinically-observed values of early arterial phase contrast enhancement of the parenchyma (∼5 HU). Similarly, early enhancement in the hepatic artery was found to agree with average clinical enhancement (180 HU). CONCLUSIONS The computational methods presented here furthered the development of the XCAT phantoms allowing for multi-timepoint contrast perfusion simulations, enabling more anthropomorphic virtual clinical trials intended for optimization of current clinical imaging technologies and applications. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Thomas J Sauer
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
| | - Ehsan Abadi
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
| | - Paul Segars
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
| | - Ehsan Samei
- Center for Virtual Imaging Trials (CVIT), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center
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Time to peak enhancement of malignant hypervascular hepatic tumors versus that of the aorta evaluating by test bolus sequence of magnetic resonance imaging. Eur J Radiol 2020; 131:109211. [DOI: 10.1016/j.ejrad.2020.109211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 07/12/2020] [Accepted: 08/05/2020] [Indexed: 11/21/2022]
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Hu D, Yu T, Duan X, Peng Y, Zhai R. Determination of the optimal energy level in spectral CT imaging for displaying abdominal vessels in pediatric patients. Eur J Radiol 2014; 83:589-94. [DOI: 10.1016/j.ejrad.2013.10.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 10/07/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
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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.
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Affiliation(s)
- Kyongtae T Bae
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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CT angiography covering both cervical and cerebral arteries using high iodine concentration contrast material with dose reduction on a 16 multidetector-row system. Neuroradiology 2009; 52:291-5. [DOI: 10.1007/s00234-009-0611-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 10/05/2009] [Indexed: 10/20/2022]
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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: 23] [Impact Index Per Article: 1.4] [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.
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Chu LL, Joe BN, Westphalen ACA, Webb EM, Coakley FV, Yeh BM. Patient-specific Time to Peak Abdominal Organ Enhancement Varies with Time to Peak Aortic Enhancement at MR Imaging. Radiology 2007; 245:779-87. [PMID: 17911535 DOI: 10.1148/radiol.2451061585] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE To retrospectively evaluate the relationship between the times to peak enhancement of the liver, pancreas, and jejunum with respect to the time to peak aortic enhancement at magnetic resonance (MR) imaging. MATERIALS AND METHODS The committee on human research approved this study and waived written informed consent. This study was HIPAA compliant. The study retrospectively identified 141 patients (63 men, 78 women; mean age, 57 years) who underwent abdominal MR imaging by using a test bolus that was monitored approximately every second for 2 minutes with a spoiled gradient-echo T1 transverse section through the upper abdomen. The times to peak enhancement of the aorta, liver, pancreas, and jejunum were recorded and correlated with the time to peak aortic enhancement, age, and sex by means of univariate and multivariate linear regression analyses. RESULTS The mean time to peak aortic enhancement was 21.1 seconds (range, 8.7-41.8 seconds). The times to peak enhancement of the liver, pancreas, and jejunum were positively and linearly correlated with the time to peak aortic enhancement (r = 0.69, 0.86, and 0.80, respectively, all P < .001) and were 3.39, 1.64, and 2.04 times longer than the time to peak aortic enhancement, respectively. Age, sex, and history of heart disease did not give additional predictive information for determining the time to peak visceral enhancement. CONCLUSION The times to peak enhancement of the liver, pancreas, and jejunum are linearly related to that of the aorta. These results could potentially allow tailored patient- and organ-specific scan delay optimization at contrast material-enhanced MR image evaluation.
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Affiliation(s)
- Lisa L Chu
- Department of Radiology, University of California-San Francisco, 505 Parnassus Ave, Box 0628, C-324C, San Francisco, CA 94143-0628, USA
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Chung YE, Kim KW, Kim JH, Lim JS, Oh YT, Chung JJ, Kim MJ. Optimal Delay Time for the Hepatic Parenchymal Enhancement at the Multidetector CT Examination. J Comput Assist Tomogr 2006; 30:182-8. [PMID: 16628029 DOI: 10.1097/00004728-200603000-00003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The objective of this study was to determine the optimal scan delay time after hepatic parenchymal enhancement using a 16-channel multidetector row helical CT (MDCT) scanner. Two hundred fifty-five consecutive patients underwent biphasic CT scans using a 16-channel MDCT. In group A (n = 125), two hepatic venous phase scans (HVP1 and HVP2) were obtained at 40 and 60 seconds, after 100-HU threshold time (T100HU) in the abdominal aorta. In group B (n = 130), HVP1 and HVP2 scans were obtained 50 and 70 seconds after T100HU. Both groups were divided into subgroups that were given different contrast media. Groups A1 and B1 received a contrast medium of 300 mgI/mL; groups A2 and B2 received a contrast medium of 370 mgI/mL. Each patient was injected with contrast medium at a dose of 2 mL/kg at a rate adjusted to the patient's body weight with a constant injection duration of 47 seconds. The attenuation values (HU) for the liver, portal vein, hepatic vein, and aorta were measured. The average HU was compared between the groups. Hepatic enhancement in the images obtained at 50 and 60 seconds after T100HU was greater (P < 0.05) than in images obtained at 40 and 70 seconds. These results were obtained with both contrast media. A few patients showed greater enhancement at a 40 seconds or 70 seconds. Hepatic enhancement was significantly greater in all scans using a contrast medium dose of 370 mgI/mL compared with the 300-mgI/mL dose (P < 0.05). Independent of the concentration of contrast medium, scan delays of 50 to 60 seconds after T100HU may provide optimal hepatic enhancement.
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Affiliation(s)
- Yong Eun Chung
- Department of Diagnostic Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
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Fenchel S, Fleiter TR, Aschoff AJ, van Gessel R, Brambs HJ, Merkle EM. Effect of iodine concentration of contrast media on contrast enhancement in multislice CT of the pancreas. Br J Radiol 2004; 77:821-30. [PMID: 15482993 DOI: 10.1259/bjr/19527646] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The purpose of this study was to determine the influence of two different iodine concentrations of the non-ionic contrast agent, Iomeprol, on contrast enhancement in multislice CT (MSCT) of the pancreas. To achieve this MSCT of the pancreas was performed in 50 patients (mean age 57+/-14 years) with suspected or known pancreatic tumours. The patients were randomly assigned to group A (n=25 patients) or group B (n=25 patients). There were no statistically significant differences in age, height or weight between the patients of the two groups. The contrast agent, Iomeprol, was injected with iodine concentrations of 300 mg ml(-1) in group A (130 ml, injection rate 5 ml s(-1)) and 400 mg ml(-1) in group B (98 ml, injection rate 5 ml s(-1)). Arterial and portal venous phase contrast enhancement (HU) of the vessels, organs, and pancreatic masses were measured and a qualitative image assessment was performed by two independent readers. In the arterial phase, Iomeprol 400 led to a significantly greater enhancement in the aorta, superior mesenteric artery, coeliac trunk, pancreas, pancreatic carcinomas, kidneys, spleen and wall of the small intestine than Iomeprol 300. Portal venous phase enhancement was significantly greater in the pancreas, pancreatic carcinomas, wall of the small intestine and portal vein with Iomeprol 400. The two independent readers considered Iomeprol 400 superior over Iomeprol 300 concerning technical quality, contribution of the contrast agent to the diagnostic value, and evaluability of vessels in the arterial phase. No differences were found for tumour delineation and evaluability of infiltration of organs adjacent to the pancreas between the two iodine concentrations. In conclusion the higher iodine concentration leads to a higher arterial phase contrast enhancement of large and small arteries in MSCT of the pancreas and therefore improves the evaluability of vessels in the arterial phase.
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Affiliation(s)
- S Fenchel
- Department of Radiology, University of Ulm, Steinhoevelstr. 9, 89075 Ulm, Germany
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Schoellnast H, Tillich M, Deutschmann HA, Deutschmann MJ, Fritz GA, Stessel U, Schaffler GJ, Uggowitzer MM. Abdominal multidetector row computed tomography: reduction of cost and contrast material dose using saline flush. J Comput Assist Tomogr 2003; 27:847-53. [PMID: 14600448 DOI: 10.1097/00004728-200311000-00002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the potential of a saline solution flush after the contrast material bolus in abdominal multidetector row CT (MDCT) in contrast material dose and cost reduction. METHODS Abdominal MDCT was performed in 78 patients who were assigned randomly to 2 groups receiving 120 mL nonionic contrast material (300 mgI/mL) alone or 100 mL of the same contrast material pushed with 40 mL of saline solution. Mean attenuation values for both groups were measured in the liver, the spleen, the pancreas, the portal vein, the inferior vena cava, and the abdominal aorta. Cost analyses were performed for both groups. RESULTS There was no significant difference in parenchymal and vascular enhancement between both groups. The difference of the enhancement was 2 HU for the liver (P = 0.11), 2 HU for the spleen (P = 0.44), 3 HU for the pancreas (P = 0.38), 9 HU for the portal vein (P = 0.11), 3 HU for the inferior vena cava (P = 0.55), and 10 HU for the aorta (P = 0.06). Taking the costs of contrast material, saline solution, and disposal material into account, 7.30 dollars was saved by the patient using a saline solution flush. CONCLUSIONS Using a saline flush after the contrast material bolus in abdominal MDCT allows an iodine dose reduction of approximately 6 g, or 17%, without impairing mean parenchymal and vascular enhancement and a cost reduction of 7.30 dollars per patient.
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Schoellnast H, Tillich M, Deutschmann HA, Stessel U, Deutschmann MJ, Schaffler GJ, Schoellnast R, Uggowitzer MM. Improvement of parenchymal and vascular enhancement using saline flush and power injection for multiple-detector-row abdominal CT. Eur Radiol 2003; 14:659-64. [PMID: 14566425 DOI: 10.1007/s00330-003-2085-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2002] [Revised: 04/17/2003] [Accepted: 09/01/2003] [Indexed: 12/11/2022]
Abstract
The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4x5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p<0.05). The improvement in mean enhancement of the liver was 9 +/- 9 HU, of the spleen 8 +/- 10 HU, of the pancreas 7 +/- 9 HU, and of the renal cortex 8 +/- 20 HU. The improvement in mean enhancement of the portal vein was 10 +/- 17 HU of the inferior vena cava 8 +/- 13 HU and of the abdominal aorta 10 +/- 17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses.
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Affiliation(s)
- Helmut Schoellnast
- Department of Radiology, University Hospital of Graz, Auenbruggerplatz 9, 8036 Graz, Austria.
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Frank P, Mahaffey M, Egger C, Cornell KK. Helical computed tomographic portography in ten normal dogs and ten dogs with a portosystemic shunt. Vet Radiol Ultrasound 2003; 44:392-400. [PMID: 12939055 DOI: 10.1111/j.1740-8261.2003.tb00475.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Contrast enhanced helical computed tomography (CT) of the liver and portal system is routinely performed in human patients. The purpose of this project is to develop a practical protocol for helical CT portography in the dog. Ten clinically normal dogs were initially evaluated to develop a protocol. Using this protocol, ten dogs with confirmed portosystemic shunts (PSS) were then evaluated. Each patient was anesthetized, and a test dose of sodium iothalamate (400 mg I/ml) at 0.55 ml/kg was injected. Serial images were acquired at the level of T12-13 or T13-L1. The time to maximum enhancement of the portal vein was determined. This time period was used as the period between the second injection (2.2 ml/kg) and the start of the helical examination of the cranial abdomen. Delay times for normal dogs ranged from 34.5 s-66.0 s (median: 43.5 s) or 1.41 s/kg-4.12 s/kg (median: 2.09 s/kg). For patients with a PSS, the delay times were 16.5-70.5 s (median: 34.5 s) or 1.47-19.17 s/kg (median: 3.39 s/kg). The aorta, caudal vena cava, portal vein, shunt vessels, and their respective branches were well visualized on the CT images. Clinical case results were surgically confirmed. The surgeons reported that the information gained from the CT portography resulted in a subjective decrease in surgical time and degree of dissection necessary compared with similar surgeries performed without angiographic information. We believe that helical CT portography in the dog will be a useful adjunct in the diagnosis of PSS. The use of helical CT portography may allow clinicians to give clients a more accurate prognosis prior to surgery and will allow patients with lesions that are not surgically correctable to avoid a costly and invasive procedure.
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Affiliation(s)
- Paul Frank
- Department of Anatomy, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
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Fenchel S, Boll DT, Fleiter TR, Brambs HJ, Merkle EM. Multislice helical CT of the pancreas and spleen. Eur J Radiol 2003; 45 Suppl 1:S59-72. [PMID: 12598029 DOI: 10.1016/s0720-048x(02)00363-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Multislice helical CT (MSCT) with its multidetector technology and faster rotation times, has led to new dimensions in spatial and temporal resolution in CT imaging. In contrast to single-slice CT, smaller slice collimations can be applied that lead to almost isotropic voxels and allow high quality multiplanar and 3-D image reconstructions. The high speed of multislice CT can be used to reduce the time needed to cover a given volume, to increase the spatial resolution along the z-axis by applying thinner slice collimations, and to cover longer anatomic volumes. The speed of MSCT allows organ imaging in clearly defined perfusion phases, e.g. the arterial, parenchymal, and portal venous perfusion phases. Contrast agents with higher iodine concentrations (400 mg iodine per ml compared with 300 mg iodine per ml) lead to higher contrast enhancement of the pancreas (arterial+portal venous phases), the kidneys (arterial+portal venous phases), the spleen (arterial phase), the wall of the small intestine (arterial+portal venous phases), the larger and smaller arteries (arterial phase), and the portal vein (portal venous phase). All of these advancements lead to improved visualization of small structures and of various pathologies, such as pancreatic tumors, liver metastases, vessel infiltration, and vascular diseases.
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Affiliation(s)
- Sabine Fenchel
- Department of Radiology, University of Ulm, Ulm, Germany.
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Rademacher G, Stengel D, Siegmann S, Petersein J, Mutze S. Optimization of contrast agent volume for helical CT in the diagnostic assessment of patients with severe and multiple injuries. J Comput Assist Tomogr 2002; 26:113-8. [PMID: 11801913 DOI: 10.1097/00004728-200201000-00017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to determine the optimal amount of contrast agent for helical CT of the trunk during primary radiologic evaluation of polytraumatized patients. METHOD Eighty-three patients with severe and multiple injuries (mean age 36.2 years) underwent standardized helical CT examination with administration of a single contrast agent bolus of iohexol (Accupaque 300) at volumes of 120, 150, and 180 ml. Image quality was estimated by two blinded radiologists using a visual analogue scale. Analysis further included density measurements in regions of interest (ROIs) placed in the ascending, descending, and abdominal aorta as well as in the liver and spleen. RESULTS The qualitative rating of the contrast agent effect after administration of 150 and 180 ml was significantly better compared with 120 ml [odds ratio (OR) 12.05, 95% confidence interval (CI) 3.50-41.52 and OR 12.14, 95% CI 3.36-43.85, respectively]. A dose increase from 120 to 150 ml resulted in a significantly better enhancement of the abdominal aorta (p = 0.006). The highest dose of 180 ml was not associated with a diagnostic gain in the other ROIs. CONCLUSION We recommend administration of 150 ml of iohexol as the optimal amount of contrast material for single phase bolus administration in emergency helical CT examination of the chest and abdomen.
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Herts BR, O'Malley CM, Wirth SL, Lieber ML, Pohlman B. Power injection of contrast media using central venous catheters: feasibility, safety, and efficacy. AJR Am J Roentgenol 2001; 176:447-53. [PMID: 11159092 DOI: 10.2214/ajr.176.2.1760447] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This study evaluates the feasibility, safety, and efficacy of power-injecting IV contrast media through central venous catheters for CT examinations. SUBJECTS AND METHODS Two hundred ninety-five CT examinations were performed during an 18-month period in 225 patients with indwelling central venous catheters. Patients were randomized to power injection either through peripheral IV catheter or through central venous catheter. Feasibility was defined as the percentage of patients with contrast material injected successfully through the randomized access route. Safety was evaluated by comparing patients with complications. Efficacy was evaluated by comparing contrast enhancement of the thoracic aorta, pulmonary artery, abdominal aorta, and liver. RESULTS Two hundred nine patients had randomization data recorded. One hundred three (94%) of 109 patients were successfully injected through their indwelling catheter compared with 42 (42%) of 100 through a peripherally placed IV catheter (p < 0.001). After reassignment for unsuccessful access, 174 patients underwent central venous catheter injection, and 51, peripheral IV catheter injection. No statistically significant difference was noted in the complications between the central venous catheter and peripheral IV catheter groups. Enhancement was greater in the thoracic aorta, pulmonary artery, and liver for the peripheral IV catheter group (p < 0.03). CONCLUSION Power injection of contrast media through central venous catheters for CT examinations is feasible and safe when set hospital guidelines and injection protocols are followed. This technique provides an acceptable alternative in patients without adequate peripheral IV access when bolus contrast enhancement is desired.
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Affiliation(s)
- B R Herts
- Department of Radiology, Hb6, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA
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Hoeffel C, Legmann P, Girardot C, Bunouf P, Mezzi K, Bonnin A. Contrast material injection for hepatic helical computed tomography. Comparative study of five protocols. Invest Radiol 1996; 31:467-71. [PMID: 8854192 DOI: 10.1097/00004424-199608000-00001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES The authors develop and compare contrast material injection protocols suitable for hepatic helical computed tomography. METHODS One hundred twenty-one patients who underwent contrast-enhanced computed tomography (CT) of the liver with spiral CT imaging were evaluated for enhancement of the liver parenchyma and for post-enhancement attenuation of the aorta and portal vein with iohexol. Patients were assigned randomly to five protocols with different flow rates, volume of contrast material, and scan delays. RESULTS Mean parenchymal contrast enhancement was statistically significantly higher with protocol 5 (biphasic injection of 100 mL of iohexol 300 (g/100 mL) at a flow rate of 1.5 mL/second followed by 25 mL at 2 mL/second; total iodine load = 37.5 g, with a scan delay of 70 seconds). The highest aortic enhancement and the second highest portal vein enhancement were obtained with this protocol. CONCLUSION The authors suggest an easily tolerated injection protocol able to ensure high parenchymal liver enhancement and satisfactory aortic and portal vein enhancement. This protocol includes a long scan delay (70 seconds), biphasic low flow injection rate, and a relatively low iodine load.
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Affiliation(s)
- C Hoeffel
- Department of Radiology, Cochin Hospital, Paris, France
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Luker GD, Siegel MJ, Bradley DA, Baty JD. Hepatic spiral CT in children: scan delay time-enhancement analysis. Pediatr Radiol 1996; 26:337-40. [PMID: 8657463 DOI: 10.1007/bf01395710] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To compare the effect of different time delays between contrast administration and the start of spiral CT scanning on hepatic enhancement in children. MATERIALS AND METHODS Forty-five children (2-9 years old, mean 6 years) with no evidence of hepatic disease were examined with spiral CT. Sequential spiral scans through the entire liver were performed following a uniphasic injection of nonionic contrast medium. In group 1 scanning started at 80 % of the contrast injection time, in group 2 scanning started at 100 % of injection time, and in group 3 scanning started at 150 % of injection time. Mean hepatic, aortic, and inferior vena caval enhancement were determined using regions-of-interest measurements. RESULTS Mean hepatic enhancement was 41.4, 47.0, and 40.6 HU for the 80 %, 100 %, and 150 % injection times, respectively. Enhancement was significantly greater in the 100 % injection time group (p < 0.05). A mean aortocaval difference of greater than 10 HU was present in all examinations. CONCLUSION Our results suggest that delaying the initiation of spiral CT scanning until the completion of the contrast injection increases hepatic enhancement in children. These data should help to improve the quality of hepatic spiral CT in pediatric patients.
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Affiliation(s)
- G D Luker
- Malinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., St. Louis, MO 63110, USA
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Nuñez D, Wester JD, Lentz KA, Amendola MA. Helical computed tomography of liver injuries: A trial of dual phase imaging. Emerg Radiol 1996. [DOI: 10.1007/bf01508161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
Helical/spiral CT technology has several potential benefits for scanning pediatric patients. These benefits include reduced sedation rates, decreased radiation exposure with scanning at extended pitch, improved image quality, and better three-dimensional and reformatted images. This paper reviews the technical and clinical considerations relevant to scanning the pediatric patient and offers suggestions for protocol development.
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Affiliation(s)
- K S White
- Department of Medical Imaging, Primary Children's Medical Center, 100 North Medical Drive, Salt Lake City, UT 84113, USA
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