High-Concentration Contrast Media in Multiphasic Abdominal Multidetector-Row Computed Tomography

Schoellnast, Helmut; Brader, Peter; Oberdabernig, Barbara; Pisail, Borjana; Deutschmann, Hannes; Fritz, G. A.; Schaffler-Schaden, Dagmar; Tillich, Manfred

doi:10.1097/01.rct.0000175502.79954.96

Cited by 27 publications

(15 citation statements)

References 17 publications

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“…Although the magnitude of hepatic parenchymal enhancement may not increase substantially by the use of a high injection rate (e.g., 4-6 ml/sec) compared with an intermediate injection rate (e.g., 2-3 ml/sec), a fast injection rate increases the magnitude of hepatic arterial enhancement and separates the peaks of hepatic arterial and hepatic parenchymal enhancement [23,61,85]. As a result, fast injections are desirable in multi-phase hepatic imaging and in detection of hypervascular liver masses [61,69,77,83,85,86] (Fig. 6).…”

Section: Contrast Enhancement Magnitudementioning

confidence: 97%

Scan and contrast administration principles of MDCT

Bae

Heiken

2005

Eur Radiol Suppl

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Because of its fast scan speed, multi-detector row CT (MDCT) imposes a challenge to optimization of contrast enhancement and scan timing. However, when this challenge is overcome with the use of precisely designed protocols, MDCT provides us with an opportunity to use contrast medium more efficiently and flexibly than with single-detector row CT (SDCT). To fully achieve the benefits of MDCT, it is crucial for radiologists and technologists to 1) understand the factors that determine contrast enhancement and scan timing for MDCT, and 2) identify the required modifications in protocol design to optimize contrast enhancement for MDCT. Clinical considerations for CTA and hepatic imaging are described in this article.

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Section: Contrast Enhancement Magnitudementioning

confidence: 97%

Scan and contrast administration principles of MDCT

Bae

Heiken

2005

Eur Radiol Suppl

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“…First, when the injection flow rate remains constant, an increase in the iodine concentration in the contrast medium yields proportionally higher amounts of iodine administered per unit of time. There is compelling evidence that, during early arterial contrast medium dynamics, increasing the iodine delivery rate -using either faster injection flow rates or a higher iodine concentration contrast medium, or both -has a profound influence on the magnitude of enhancement of the arterial system [5,16,17] of wellperfused organs, such as the renal cortex, pancreas and spleen [17,18], and of hypervascular liver tumours [5][6][7][8]. The second factor for the differences we found in tumour conspicuity and arterial enhancement between MCCM and HCCM during the hepatic arterial phase is the discrepancy in the duration of the contrast material injection (on average, 30 s vs 24 s, respectively, for scheme B) using a fixed injection flow rate.…”

Section: Discussionmentioning

confidence: 99%

Effect of varying contrast material iodine concentration and injection technique on the conspicuity of hepatocellular carcinoma during 64-section MDCT of patients with cirrhosis

Guerrisi

Marin

Nelson

et al. 2011

BJR

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Objectives: The aim of this study was to compare the intraindividual effects of contrast material with two different iodine concentrations on the conspicuity of hepatocellular carcinoma (HCC) and vascular and hepatic contrast enhancement during multiphasic, 64-section multidetector row CT (MDCT) in patients with cirrhosis using two contrast medium injection techniques. Methods: Patients were randomly assigned to one of two groups with an equal iodine dose but different contrast material injection techniques: scheme A, fixed injection duration (25 s), and scheme B, fixed injection flow rate (4 ml s 21). For each group, patients were randomised to receive both moderate-concentration contrast medium (MCCM) and high-concentration contrast medium (HCCM) during two CT examinations within 3 months. Enhancement of the aorta, liver and portal vein and the tumour-toliver contrast-to-noise ratio (CNR) were compared between MCCM and HCCM. Results: 30 patients (mean age 59 years; range 45-80 years; 16 patients in scheme A and 14 in scheme B) with a total of 31 confirmed HCC nodules were prospectively enrolled. For scheme B, the mean contrast enhancement of the aorta and tumour-to-liver CNR were significantly higher with HCCM than with MCCM during the hepatic arterial phase (+350.5 HU vs +301.1 HU, p50.001, and +7.5 HU vs +5.5 HU, p50.004). For both groups, there was no significant difference between MCCM and HCCM for all other comparisons. Conclusion: For a constant injection flow rate, HCCM significantly improves the conspicuity of HCC lesions and aortic enhancement during the hepatic arterial phase on 64-section MDCT in patients with cirrhosis. Along with MRI, multidetector row CT (MDCT) is the modality of choice for the diagnosis and follow-up of patients with hepatocellular carcinoma (HCC), as well as for tumour burden assessment. With the advent of volume MDCT, enabling the acquisition of 64 or more sections during a single gantry rotation, it has become possible to scan the entire abdomen with submillimetre section widths within a short scan time (less than 5 s for 300 mm of coverage). Although this technique has shown several advantages over conventional CT, including better discrimination between different circulatory phases, the potential for scanning during peak organ enhancement throughout the entire imaging volume and true isotropic CT data sets, it has raised considerable challenges for the design of scanning and contrast material injection protocols that are optimised for the detection of hypervascular HCC lesions [1]. Recent investigations have emphasised the importance of using test bolus or bolus-tracking methods to synchronise CT data acquisition with the peak tumourto-liver contrast for hypervascular HCC lesions [2,3]; however, the most effective contrast medium injection technique for maximising tumour enhancement during the narrow temporal acquisition of modern MDCT systems remains largely unexplored. Previous studies with early generation MDCT scanners reported conflicting results with varying volumes a...

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“…CM injection protocols are determined by a combination of several factors, including CM volume (27)(28)(29)(30)(31), CM concentration, rate of injection, and type of injection (27,32). The rationale of any injection protocol is to deliver an adequate amount of CM in order to obtain optimal parenchymal and vascular enhancement.…”

Section: Discussionmentioning

confidence: 99%

Analysis of the Effects of Different Iodine Concentrations on the Characterization of Small Renal Lesions Detected by Multidetector Computed Tomography Scan: A Pilot Study

Lee

Kim

Cho

et al. 2017

J Korean Soc Radiol

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Multidetector computed tomography (MDCT) of the abdominal solid organs, including the liver and kidney, is an essential imaging modality of routine clinical practice for the diagnosis, treatment planning, and follow-up of many diseases. The diagnostic accuracy of CT examination is highly dependent on the imaging protocols and, in particular, on contrast media (CM) Purpose: Our objective was to compare the effects of different iodine concentrations on characterizing small renal lesions. Materials and Methods: Thirty-eight patients were enrolled in this study. All patients underwent an initial CT scan using 370 mgI/mL iodinated contrast media. Patients were then randomized into two groups for a follow-up CT. Group A (n = 19) received 250 mgI/mL iodinated contrast media, and group B (n = 19) received 300 mgI/mL contrast media. The mean Hounsfield units (HU values) of small renal lesions with a maximum size of less than 2 cm were calculated. Signal to noise ratios (SNR values) were likewise evaluated. Three uroradiologists assessed the lesion's conspicuity and the diagnostic influence of the artifact's proximity to the adjacent renal parenchyma. Results: In group A, there were significant differences between the HU values of renal lesions and those of the adjacent renal parenchyma between the initial and follow-up CT. Conversely, in group B, there was no significant difference. Moreover, SNR values showed no statistically significant difference between both groups. Regarding lesion conspicuity, only one reader identified a significant difference (p = 0.032) in group A; whereas in group B, there was no statistical difference. The artifact's proximity to the adjacent renal parenchyma did not appear to have any diagnostic influence on differentiating the two (p < 0.05). Conclusion:In evaluating small renal lesions, 300 mgI/mL instead of 370 mgI/mL contrast media can be used; however, it is important to note that the use of 250 mgI/ mL contrast media may reveal different results from that of 370 mgI/mL contrast media. Index terms

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High-Concentration Contrast Media in Multiphasic Abdominal Multidetector-Row Computed Tomography

Abstract: A high iodine flow rate in multiphasic abdominal MDCT improves enhancement of the aorta and the pancreas during the arterial phase but does not influence later phases.

Cited by 27 publications

References 17 publications

Scan and contrast administration principles of MDCT

Scan and contrast administration principles of MDCT

Effect of varying contrast material iodine concentration and injection technique on the conspicuity of hepatocellular carcinoma during 64-section MDCT of patients with cirrhosis

Analysis of the Effects of Different Iodine Concentrations on the Characterization of Small Renal Lesions Detected by Multidetector Computed Tomography Scan: A Pilot Study

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