Low Contrast Agent and Radiation Dose Protocol for Hepatic Dynamic CT of Thin Adults at 256–Detector Row CT: Effect of Low Tube Voltage and Hybrid Iterative Reconstruction Algorithm on Image Quality

Nakaura, Takeshi; Nakamura, Shinichi; Maruyama, Natsuki; Funama, Yoshinori; Awai, Kazuo; Harada, Kazunori; Uemura, Sachiko; Yamashita, Yasuyuki

doi:10.1148/radiol.12111082

Cited by 127 publications

(91 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A decrease in the X-ray tube current leads to an increase in image noise without affecting the CT attenuation (18,28,29), which was also demonstrated by the present study results. Image noise is certainly a factor that strongly affects the segmentation process, particularly especially at the determination of the initial contour of objects for the deformable model application (18).…”

Section: Discussionsupporting

confidence: 88%

“…However, the effect of low kilovoltage and low tube current on segmentation of solid organ has not been widely evaluated. A decrease in the X-ray tube voltage resulted in reduced amount of penetrating radiation, and thus an increase in object attenuation and image noise (28)(29)(30). Numerous studies have focused on the lower kilovoltage application in iodinated contrast agent CT scanning, since the lower kilovoltage imaging resulted in evidently higher attenuation of iodine (28,29).…”

Section: Discussionmentioning

confidence: 99%

“…A decrease in the X-ray tube voltage resulted in reduced amount of penetrating radiation, and thus an increase in object attenuation and image noise (28)(29)(30). Numerous studies have focused on the lower kilovoltage application in iodinated contrast agent CT scanning, since the lower kilovoltage imaging resulted in evidently higher attenuation of iodine (28,29). However, in the present study, the object density increased by only ~5 HU at 80 kVp, compared with CT images at 120 kVp, while the image noise was slightly increased simultaneously.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of various environments and computed tomography scanning parameters on renal volume measurements in vitro: A phantom study

Liu

Zhu

Tang

et al. 2016

Experimental and Therapeutic Medicine

View full text Add to dashboard Cite

Abstract. Kidney volume is an important parameter in clinical practice, and accurate assessment of kidney volume is vital. The aim of the present study was to evaluate the effect of various environments, tube voltages, tube currents and slice thicknesses on the accuracy of a novel segmentation software in determining renal volume on computed tomography (CT) images. The volumes of potatoes and porcine kidneys were measured on CT images and compared with the actual volumes, which were determined by a water displacement method. CT scans were performed under various situations, including different environments (air or oil); tube voltages/tube currents (80 kVp/200 mAs, 120 kVp/200 mAs, 120 kVp/100 mAs); and reconstructed slice thicknesses (0.75 or 1.5 mm). Percentage errors (PEs) relative to the reference standards were calculated. In addition, attenuation and image noise under different CT scanning parameters were compared. Student's t-test was also used to analyze the effect of various conditions on image quality and volume measurements. The results indicated that the volumes measured in oil were closer to the actual volumes (P<0.05). Furthermore, attenuation and image noise significantly increased when using a tube voltage of 80 kVp, while the mean PEs between 120 and 80 kVp voltages were not significantly different. The mean PEs were greater when using a tube current of 100 mAs compared with a current of 200 mAs (P<0.05). In addition, the volumes measured on 1.5 mm slice thickness were closer to the actual volumes (P<0.05). In conclusion, different environments, tube currents and slice thicknesses may affect the volume measurements. In the present study, the most accurate volume measurements were obtained at 120 kVp/200 mAs and a slice thickness of 1.5 mm. IntroductionKidney volume is an important parameter that must be considered for the selection of appropriate management, surgery planning and evaluation of disease status in patients with kidney disease (1-5). Therefore, precise kidney volumetry has been receiving increasing attention clinically. Typically, kidney size or volume measurement is evaluated using various cross-sectional imaging modalities, including ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) (6-12). US is an easily used and low-cost technique. Using this method, the renal volume is usually calculated by measuring the three axes of the kidney (length, width and thickness) and then applying these values to an ellipsoid formula (6). However, the shape of the kidney varies greatly in the majority of cases, and as a result, errors in volume calculations by US may occur (6,7). MRI provides outstanding sensitivity for the discrimination of soft tissues that facilitates the segmentation of the kidney (8). However, various factors, such as spatial resolution, artifacts and signal non-uniformities, can affect the accuracy in image segmentation by MRI (9,10). With the advancements in multidetector CT (MDCT), improvements of spatial resolution and time resolution, the a...

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of various environments and computed tomography scanning parameters on renal volume measurements in vitro: A phantom study

Liu

Zhu

Tang

et al. 2016

Experimental and Therapeutic Medicine

View full text Add to dashboard Cite

show abstract

“…16 To achieve a radiation dose reduction, CT scanners with more detectors (eg, 256-or 320-detector CT scanners) and iterative reconstruction algorithms might be useful. 17 Further experimental and clinical studies are required to clarify this issue. Our study has some limitations.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Dynamic Contrast-Enhanced 3T MR and 64-Row Multidetector CT Angiography for the Localization of Spinal Dural Arteriovenous Fistulas

Oda¹,

Utsunomiya²,

Hirai³

et al. 2013

American Journal of Neuroradiology

View full text Add to dashboard Cite

show abstract

“…The most promising and currently available technology to reduce the radiation dose in computed tomography (CT) is the use of iterative reconstruction methods 5,[10][11][12][13][14][15] in combination with the reduction of tube voltage or tube current. Unfortunately, the details of iterative reconstruction methods, which are available on commercial CT systems, are not open to the public.…”

mentioning

confidence: 99%

Evaluation of an iterative model–based reconstruction algorithm for low-tube-voltage (80 kVp) computed tomography angiography

et al. 2014

View full text Add to dashboard Cite

Abstract. The objective of this study was to investigate the improvement in diagnostic quality of an iterative model-based reconstruction (IMBR) algorithm for low-tube-voltage (80-kVp) and low-tube-current in abdominal computed tomography angiography (CTA). A total of 11 patients were imaged on a 256-slice multidetector computed tomography for visualization of the aorta. For all patients, three different reconstructions from the low-tube-voltage data are generated: filtered backprojection (FBP), IMBR, and a mixture of both IMBR þ FBP. To determine the diagnostic value of IMBR-based reconstructions, the image quality was assessed. With IMBRbased reconstructions, image noise could be significantly reduced, which was confirmed by a highly improved contrast-to-noise ratio. In the image quality assessment, radiologists were able to reliably detect more third-order and higher aortic branches in the IMBR reconstructions compared to FBP reconstructions. The effective dose level was, on average, 3.0 mSv for 80-kVp acquisitions. Low-tube-voltage CTAs significantly improve vascular contrast as presented by others; however, this effect in combination with IMBR enabled yet another substantial improvement of diagnostic quality. For IMBR, a significant improvement of image quality and a decreased radiation dose at low-tube-voltage can be reported. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

Low Contrast Agent and Radiation Dose Protocol for Hepatic Dynamic CT of Thin Adults at 256–Detector Row CT: Effect of Low Tube Voltage and Hybrid Iterative Reconstruction Algorithm on Image Quality

Abstract: A low tube voltage and the hybrid iterative reconstruction algorithm can dramatically decrease radiation and contrast agent doses with adequate image quality at hepatic dynamic CT of thin adults with use of a 256-detector row scanner.

Cited by 127 publications

References 48 publications

Effect of various environments and computed tomography scanning parameters on renal volume measurements in vitro: A phantom study

Effect of various environments and computed tomography scanning parameters on renal volume measurements in vitro: A phantom study

Comparison of Dynamic Contrast-Enhanced 3T MR and 64-Row Multidetector CT Angiography for the Localization of Spinal Dural Arteriovenous Fistulas

Evaluation of an iterative model–based reconstruction algorithm for low-tube-voltage (80 kVp) computed tomography angiography

Contact Info

Product

Resources

About