Pediatric multidetector computed tomography using tube current modulation and a patient image gallery

Honnef, Dagmar; Mahnken, Andreas H.; Haras, G.; Wildberger, Joachim E.; Staatz, Gundula; Das, Marco; Barker, Michael; Stanzel, S.; Günther, Rolf W.; Hohl, C.

doi:10.1080/02841850801950095

Cited by 5 publications

(3 citation statements)

References 23 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several investigators have studied methods for reducing patient doses CT examinations (2–13) . For example, Kostas Perisinakis showed that the dose reduction caused by a 20° angled scanning of the brain was approximately 33% (2) .…”

Section: Introductionmentioning

confidence: 99%

Dose reduction in CT using bismuth shielding: measurements and Monte Carlo simulations

Chang

Lee

Choo

et al. 2009

Radiation Protection Dosimetry

View full text Add to dashboard Cite

Objective In this research, using direct measurements and Monte Carlo calculations, we evaluated the potential dose reduction achieved by bismuth shielding in computed tomography. Patient dose was measured using an ionization chamber in a polymethylmethacrylate (PMMA) phantom which had five measurement points at the center and periphery. We performed simulations using the MCNPX code. For both the bare and the bismuth-shielded phantom, the differences of dose values between experiment and simulation were within 9%. The dose reductions due to the bismuth shielding were 1.2–55% depending on the measurement points, X-ray tube voltage, and the type of shielding. The amount of dose reduction was significant for the position covered by bismuth shielding (34–46% for head and 41–55% for body phantom in average) and negligible for other peripheral positions. The artifact on the reconstructed images were minimal when the distance between the shielding and the organs was more than 1 cm, and hence the shielding should be selectively located to protect critical organs such as the eye lens, thyroid, and breast. The simulation results using PMMA phantom was compared with those using a realistically voxelized phantom (KTMAN-2). For eye and breast, the simulation results using PMMA and KTMAN-2 phantom were similar with each other while, for thyroid, the simulation results were different due to the discrepancy of locations and the size of phantoms. The dose reductions achieved by bismuth and lead shielding were compared with each other and the results showed that the difference of the dose reductions achieved by two materials was less than 2~3 %.

show abstract

Section: Introductionmentioning

confidence: 99%

Dose reduction in CT using bismuth shielding: measurements and Monte Carlo simulations

Chang

Lee

Choo

et al. 2009

Radiation Protection Dosimetry

View full text Add to dashboard Cite

show abstract

“…CT manufacturers started to provide paediatric color-coded protocols with weight or size-adapted tube current values in order to improve the CT scanner parameters adjustments. More recently computersimulated images for pre-examination overview of the expected image quality are also available (Frush et al 2002, Honnef et al 2008a, Honnef et al 2008b). The manufacturer recommended paediatric protocols are installed on the system and are arranged in colors according to height and weight for easy selection.…”

Section: Optimization and Unique Consideration In Paediatric Ctmentioning

confidence: 99%

Optimization of Image Quality in Paediatric Computed Tomography

Protik¹

2021

Preprint

View full text Add to dashboard Cite

In this study the effects of ASIR™ and collimation on CT image quality (IQ) parameters were quantified. Catphan®600 phantom studies were performed on a GE HD750 64-slice scanner to investigate the impact of collimation 0.625mm vs. 5mm on the overall IQ. For noise and dose reduction ASIR™ was tested on 0.625mm collimation. The varying %ASIR™, scanned at 150mA and variable kVp and 50% ASIR™ compared to FBP on wide kVp/mA range was used. Image noise, CT# accuracy and uniformity, spatial and contrast resolution, MTF, CNR and Wiener spectrum analysis were performed on 0.625mmAX slices, 5mmAXMPR and 2mmCORMPR. Incremental advantages and disadvantages were seen with stepwise increase in %ASIR™. The 50% ASIR™ was found to be optimal blend for diagnostic quality and has potential for dose reduction in paediatric CT. This quantitative data could be used to design ASIR™-enhanced protocols with consideration of diagnostic task, balancing image quality and radiation dose.

show abstract

“…Pediatric imaging departments developed their own tables with tube current values adjusted to the patient's age, weight (Donnelly et al 2001) or diameter (Starck et al 2002). Manufacturers subsequently provided dedicated pediatric protocols with weight or size-adapted tube current values (Frush et al 2002), or more recently, computer-simulated images intended to provide a pre-examination overview of the expected image quality (Honnef et al 2008a(Honnef et al , 2008b. However, the rationale for such settings remains debatable, as they are still based on a subjective definition of image quality.…”

Section: Introductionmentioning

confidence: 99%

The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms

et al. 2009

View full text Add to dashboard Cite

This study assessed and compared various image quality indices in order to manage the dose of pediatric abdominal MDCT protocols and to provide guidance on dose reduction. PMMA phantoms representing average body diameters at birth, 1 year, 5 years, 10 years and 15 years of age were scanned in a four-channel MDCT with a standard pediatric abdominal CT protocol. Image noise (SD, standard deviation of CT number), noise derivative (ND, derivative of the function of noise with respect to dose) and contrast-to-noise ratio (CNR) were measured. The 'relative' low-contrast detectability (rLCD) was introduced as a new quantity to adjust LCD to the various phantom diameters on the basis of the LCD(1%) assessed in a Catphan phantom and a constant central absorbed dose. The required variations of CTDIvol(16) with respect to phantom size were analyzed in order to maintain each image quality index constant. The use of a fixed SD or CNR level leads to major dose ratios between extreme patient sizes (factor 22.7 to 44 for SD, 31.7 to 51.5 for CNR(2.8%)), whereas fixed ND and rLCD result in acceptable dose ratios ranging between factors of 2.9 and 3.9 between extreme phantom diameters. For a 5-9 mm rLCD1(%), adjusted ND values range between -0.84 and -0.11 HU mGy(-1). Our data provide guidance on dose reduction on the basis of patient dimensions and the required rLCD (e.g., to get a constant 7 mm rLCD(1%) for abdominal diameters of 10, 13, 16, 20 and 25 cm, tube current-time product should be adjusted in order to obtain CTDIvol(16) values of 6.2, 7.2, 8.8, 11.6 and 17.7 mGy, respectively).

show abstract

Pediatric multidetector computed tomography using tube current modulation and a patient image gallery

Abstract: The IG enabled us to prospectively reduce the tube current and adapt the required image quality to the clinical question. Additional dose reduction was achieved with application of CARE Dose; nevertheless, the images are comparable to the simulated images of the IG.

Cited by 5 publications

References 23 publications

Dose reduction in CT using bismuth shielding: measurements and Monte Carlo simulations

Dose reduction in CT using bismuth shielding: measurements and Monte Carlo simulations

Optimization of Image Quality in Paediatric Computed Tomography

The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms

Contact Info

Product

Resources

About