Low-Dose Computed Tomography With Adaptive Statistical Iterative Reconstruction and Low Tube Voltage in Craniocervical Computed Tomographic Angiography

Introduction The aim of this study was to evaluate the radiation dose and image quality at low tube-voltage pediatric chest computed tomographic angiography (CTA) that applies the same contrast-to-noise ratio (CNR) index as the standard tube voltage technique. Materials and Methods Contrast-enhanced chest CTA scans of 100 infants were acquired on a 64-row multidetector computed tomography (MDCT) scanner. In the retrospective study, we evaluated 50 images acquired at 120 kVp; the image noise level was set at 25 Hounsfield units. In the prospective study, we used an 80-kVp protocol; the image noise level was 40 Hounsfield units because the iodine contrast was 1.6 times higher than on 120-kVp scans; the CNR was as in the 120-kVp protocol. We compared the CT number, image noise, CT dose index volume (CTDIvol), and the dose-length product on scans acquired with the 2 protocols. A diagnostic radiologist and a pediatric cardiologist visually evaluated all CTA images. Results The mean CTDIvol and the mean dose-length product were 0.5 mGy and 7.8 mGy-cm for 80- and 1.2 mGy and 20.8 mGy-cm for 120-kVp scans, respectively ( P < .001). The mean CTDIvol was 42% lower at 80 kVp than at 120 kVp, and there was no significant difference in the visual scores assigned to the CTA images ( P = .28). Conclusions With the CNR index being the same at 80-kVp and 120-kVp imaging, the radiation dose delivered to infants subjected to chest CTA can be reduced without degradation of the image quality.

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Combination of a Low-Tube-Voltage Technique With Hybrid Iterative Reconstruction (iDose) Algorithm at Coronary Computed Tomographic Angiography

Journal of Computer Assisted Tomography ◽

10.1097/rct.0b013e31821fee94 ◽

2011 ◽

Vol 35 (4) ◽

pp. 480-485 ◽

Cited By ~ 104

Author(s):

Yoshinori Funama ◽

Katsuyuki Taguchi ◽

Daisuke Utsunomiya ◽

Seitaro Oda ◽

Yumi Yanaga ◽

...

Keyword(s):

Iterative Reconstruction ◽

Computed Tomographic Angiography ◽

Tube Voltage ◽

Coronary Computed Tomographic Angiography ◽

Computed Tomographic ◽

Low Tube Voltage ◽

Hybrid Iterative Reconstruction ◽

Tomographic Angiography

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Advantages and disadvantages of single-source dual-energy whole-body CT angiography with 50% reduced iodine dose at 40 keV reconstruction

British Journal of Radiology ◽

10.1259/bjr.20201276 ◽

2021 ◽

pp. 20201276

Author(s):

Yoshifumi Noda ◽

Fumihiko Nakamura ◽

Noriyuki Yasuda ◽

Toshiharu Miyoshi ◽

Nobuyuki Kawai ◽

...

Keyword(s):

Background Noise ◽

Computed Tomographic Angiography ◽

Dual Energy ◽

Whole Body ◽

Adaptive Statistical Iterative Reconstruction ◽

Computed Tomographic ◽

Statistical Iterative Reconstruction ◽

Almost All ◽

Tomographic Angiography ◽

Iodine Dose

Objectives: To assess the feasibility of whole-body dual-energy computed tomographic angiography (DECTA) at 40 keV with 50% reduced iodine dose protocol. Methods: Whole-body CTA was performed in 65 patients; 31 of these patients underwent 120 kVp single-energy computed tomographic angiography (SECTA) with standard iodine dose (600 mgI/kg) and 34 with 40 keV DECTA with 50% reduced iodine dose (300 mgI/kg). SECTA data were reconstructed with adaptive statistical iterative reconstruction of 40% (SECTA group), and DECTA data were reconstructed with adaptive statistical iterative reconstruction of 40% (DECTA-40% group) and 80% (DECTA-80% group). CT numbers of the thoracic and abdominal aorta, iliac artery, background noise, signal-to-noise ratio (SNR), and arterial depiction were compared among the three groups. The CT dose index volumes (CTDIvol) for the thorax, abdomen, and pelvis were compared between SECTA and DECTA protocols. Results: The vascular CT numbers and background noise were found to be significantly higher in DECTA groups than in the SECTA group (p < 0.001). SNR was significantly higher in the order corresponding to DECTA-80%, SECTA, and DECTA-40% (p < 0.001). The arterial depiction was comparable in almost all arteries; however, intrapelvic arterial depiction was significantly worse in DECTA groups than in the SECTA group (p < 0.0001–0.017). Unlike the pelvic region (p = 0.055), CTDIvol for the thorax (p < 0.0001) and abdomen (p = 0.0031) were significantly higher in the DECTA protocol than in the SECTA protocol. Conclusion: DECTA at 40 keV with 50% reduced iodine dose provided higher vascular CT numbers and SNR than SECTA, and almost comparable arterial depiction, but had a degraded intrapelvic arterial depiction and required a larger radiation dose. Advances in knowledge: DECTA enables 50% reduction of iodine dose while maintaining image quality, arterial depiction in almost all arteries, vascular CT numbers, and SNR; however, it does not allow clear visualization of intrapelvic arteries, requiring a slightly larger radiation dose compared with SECTA with standard iodine dose.

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