scholarly journals Intra-individual diagnostic image quality and organ-specific-radiation dose comparison between spiral cCT with iterative image reconstruction and z-axis automated tube current modulation and sequential cCT

2016 ◽  
Vol 3 ◽  
pp. 182-190 ◽  
Author(s):  
Holger Wenz ◽  
Máté E. Maros ◽  
Mathias Meyer ◽  
Joshua Gawlitza ◽  
Alex Förster ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Radiation Dose ◽  
Diagnostic Image Quality ◽  
Tube Current Modulation ◽  
Diagnostic Image ◽  
Current Modulation ◽  
Dose Comparison ◽  
Tube Current ◽  
Organ Specific

scholarly journals Influence of Image Acquisition on Radiation Dose and Image Quality: Full versus Narrow Phase Window Acquisition Using 320 MDCT

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Faisal Khosa ◽  
Atif Khan ◽  
Khurram Nasir ◽  
Waqas Shuaib ◽  
Matthew Budoff ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Ordinal Scale ◽  
Diagnostic Image Quality ◽  
Dose Length Product ◽  
Diagnostic Image ◽  
Lower Radiation Dose ◽  
Tube Current ◽  
Dose Modulation ◽  
Mean Heart Rate

Purpose. To compare radiation dose and image quality using predefined narrow phase window versus complete phase window with dose modulation during R-R using 320-row MDCTA.Methods. 114 patients underwent coronary CTA study using 320-row MDCT scanner. 87 patients with mean age (61 + 13 years), mean BMI (29 + 6), and mean heart rate (HR) (58 + 7 bpm) were imaged at predefined 66–80% R-R interval and then reconstructed at 75% while 27 patients with mean age (63 + 16 years), mean BMI (28 + 5), and mean HR (57 + 7 bpm) were scanned throughout the complete R-R interval with tube current modulation. The effective dose (ED) was calculated from dose length product (DLP) and conversionk(0.014 mSv/mGy/cm). Image quality was assessed using a three-point ordinal scale (1 = excellent, 2 = good, and 3 = nondiagnostic).Results. Both groups were statistically similar to each other with reference of HR (P=0.59), BMI (P=0.17), and tube current mAs (P=0.68). The median radiation dose was significantly higher in those scanned with complete R-R phase window versus narrow phase window (P<0.0001). Independently of patient and scan parameters, increased phase window was associated with higher radiation dose (P<0.001). Image quality was better among those scanned with narrow phase window versus complete phase window (P<0.0001).Conclusion. Our study supports that good HR control and predefined narrow window acquisition result in lower radiation dose without compromising diagnostic image quality for coronary disease evaluation.

scholarly journals Image quality assessment of deep learning image reconstruction in computed tomography using tube current modulation: a phantom study

2021 ◽  
Author(s):  
kazuhiro takeuchi ◽  
Yasuhiro Ide ◽  
Yuichiro Mori ◽  
Yusuke Uehara ◽  
Hiroshi Sukeishi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Deep Learning ◽  
Image Reconstruction ◽  
Image Quality ◽  
Quality Characteristics ◽  
Image Noise ◽  
Tube Current Modulation ◽  
Current Modulation ◽  
Tube Current ◽  
The Impact

Abstract The novel deep learning image reconstruction (DLIR) is known to change its image quality characteristics according to object contrast and image noise. In clinical practice, computed tomography (CT) image noise is usually controlled by tube current modulation (TCM) to accommodate changes in object size. This study aimed to evaluate the image quality characteristics of DLIR for different object sizes when in-plane noise is controlled by TCM. We used Mercury 4.0 phantoms with different object sizes. Phantom image acquisition was performed on a GE Revolution CT system to investigate the impact of the DLIR algorithm compared to standard reconstructions: filtered back projection (FBP) and hybrid iterative reconstruction (hybrid-IR). For image quality evaluation, the noise power spectrum (NPS), task-based transfer function (TTF), and detectability index (d') were determined. The NPS of DLIR was very similar to that of FBP, and the information in the high-frequency region was maintained. In terms of TTF, DLIR showed higher resolution than hybrid-IR at low- to medium-contrast (Δ50, Δ90HU), but not necessarily higher than FBP. At the simulated contrast and lesion size, DLIR showed higher detectability than hybrid-IR, regardless of the phantom size. In this study, we evaluated a novel DLIR algorithm by reproducing clinical behaviors. The findings indicate that DLIR produces higher image quality than hybrid-IR regardless of the phantom size, although it depends on the reconstruction strength.

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