Optimal window settings in single-source dual-energy computed tomography of the abdomen

Noda, Yoshifumi; Goshima, Satoshi; Kozaka, Kazuto; Yoneda, Norihide; Mizuno, Nozomi; Kato, Akiko; Fujimoto, Keita; Tsuji, Yusuke; Miyoshi, Toshiharu; Kawada, Hiroshi; Kawai, Nobuyuki; Tanahashi, Yoshikatsu

doi:10.1016/j.ejrad.2018.10.012

Cited by 20 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, the SNRs of MPV in the DECT group were superior to the SECT group, which is consistent with the study of Noda Y et al (23,24). The major cause was the existence or absence of an automated tube current modulation scheme.…”

Section: Signal (Hu) Noise (Sd) and Signal-to-noise Ratio (Snr)supporting

confidence: 90%

Comparison of radiation dose and image quality between fast kVp switching dual-energy CT and routine single-energy CT for whole abdomen at King Chulalongkorn Memorial Hospital

Khemkhangboon

View full text Add to dashboard Cite

Abdominal computed tomography (CT) using a single energy protocol is a common imaging procedure in hospitals. As CT technology has continued to evolve, dual-energy protocols (DECT) have emerged as a new option. A spectral CT scanner with fast kVp switching was installed at King Chulalongkorn Memorial Hospital in 2017, and its clinical utility in emergency patients has not yet been studied. This study aims to compare the radiation dose and image quality between DECT and SECT in abdominal CT for emergency patients. The study retrospectively collected CT data from 130 standard-sized adult patients who underwent contrast-enhanced using the 256-slice MDCT. CT Contrast media was intravenously injected of iobitridol at a dose of 2.0 mL/kg with a flow rate of 2 mL/s through the median cubital vein. After the contrast medium was administered for 90 s, fast kVp-switching DECT (80/140 kVp,) and SECT (120 kVp) enhanced abdominal CT was performed. The scanning parameters for fast kVp-switching between 80 and 140-kVp were as follows: tube current, GSI Assist; detector collimation 80 x 0.625 mm; rotation speed 0.6 s; pitch factor 0.992:1. The scanning parameters for single-energy CT were as follows: 120 kVp, tube current 3D mA modulation; detector collimation 80 x 0.625 mm; rotation speed 0.5 s; pitch factor 0.992:1. The radiation dose was evaluated for both protocols in terms of CTDIvol. Objective analysis was performed by measuring the region of interest (ROI) at 5 abdominal structures: aorta, main portal vein, liver, spleen, and psoas muscle in order to evaluate signal (HU), noise (SD), and signal-to-noise ratio (SNR). Subjective image quality was evaluated by two radiologists who have similar experience in terms of diagnostic acceptability on a 4-point scale and image noise on a 3-point scale following the European Guidelines on Quality Criteria. There was no statistically significant difference in average CTDIvol between SECT (10.7?2.3 mGy) and DECT (10.3?2.8 mGy) (p>0.05). The objective image quality analysis indicated that DECT had significantly higher signal and noise values compared to SECT for all measured structures (p<0.05), but there was no significant difference in SNR except MPV between the two groups (p>0.05). The subjective image quality analysis showed no significant difference in diagnostic acceptability and image noise between SECT and DECT as evaluated by both radiologists (p>0.05). In conclusion, the fast kV switching DECT protocol used in this study provides similar objective image quality and equivalent subjective image quality with a similar level of radiation dose as SECT. Therefore, the results of this study could be implemented as a routine protocol in the emergency room to reduce patient radiation dose while maintaining image quality and accelerating patient diagnostic workflow.

show abstract

Section: Signal (Hu) Noise (Sd) and Signal-to-noise Ratio (Snr)supporting

confidence: 90%

Comparison of radiation dose and image quality between fast kVp switching dual-energy CT and routine single-energy CT for whole abdomen at King Chulalongkorn Memorial Hospital

Khemkhangboon

View full text Add to dashboard Cite

show abstract

“…The image quality and enhancement characteristics of VMIs at 75-77 keV has been demonstrated to correspond to conventional 120-kVp single-energy CT images (17)(18)(19). CT numbers exponentially increase with the decreasing kiloelectron-volt levels, and aortic enhancement on 40-keV VMIs is reported to be nearly twofold compared with 60 keV (20). In our phantom study, we found that CT numbers at 40 keV were more than twice the attenuation at 60 keV, thus providing an opportunity to optimize the trigger threshold on the basis of the desired kiloelectron volt of the image to be generated.…”

Section: Discussionmentioning

confidence: 86%

Optimized Bolus Threshold for Dual-Energy CT Angiography with Monoenergetic Images: A Randomized Clinical Trial

et al. 2021

Self Cite

View full text Add to dashboard Cite

C T angiography (CTA) has been widely used for a broad range of indications: evaluation of aortic vascular anatomy and disease condition (1), therapy planning for endovascular aortic aneurysm repair and transcatheter aortic valve implantation (2,3), and follow-up after endovascular aortic aneurysm repair (4). Surveillance imaging with CTA after endovascular aortic aneurysm repair is routinely recommended in detecting potential complications such as endoleak (5). Patients undergoing endovascular aortic aneurysm repair often have associated medical comorbidities including varying degrees of renal dysfunction. Intravenous iodinated contrast agent administration for CTA often poses the risk for contrast agent-associated acute renal injury, which is related to the iodine load (6,7).Virtual monochromatic images (VMIs) generated from a dual-energy CT (DECT) acquisition have been reported to enable lower iodine load in several studies (8-10). VMIs at lower energy levels show increased CT numbers because of approximation of the energy level closer to the k-edge of iodine at 33 keV (11). DECT angiography (DECTA) with reduced iodine dose (24 g) provided up to 185% higher CT attenuation and 25% higher contrast-to-noise ratio at low-energy VMIs compared with conventional single-energy CTA (SECTA) at 120 kVp by using a standard iodine dose (33.3 g) ( 9). Studies investigating DECTA commonly use a threshold of 100 HU for triggering scanning with the bolus-tracking technique (9,12-14), a threshold adapted from traditional single-energy CT Background: The bolus-tracking technique from single-energy CT has been applied to dual-energy CT (DECT) without optimization or validation. Further optimization is imperative because of a paucity of literature and differences in the attenuation profile of virtual monoenergetic images (VMIs).Purpose: To determine the optimal trigger threshold with bolus-tracking technique for DECT angiography (DECTA) in a phantom study and assess the feasibility of an optimized threshold for bolus-tracking technique in DECTA at 40 keV with a 50% reduced iodine dose in human participants. Materials and Methods:A phantom study with rapid kilovoltage-switching DECT was performed to determine the optimal threshold for each kiloelectron-volt VMI. In a prospective study, consecutive participants who underwent whole-body CT angiography (CTA) from August 2018 to July 2019 were randomized into three groups: single-energy CTA (SECTA) with standard iodine dose (600 mg of iodine per kilogram), DECTA with 50% reduced iodine dose (300 mg of iodine per kilogram) by using a conventional threshold, and DECTA with 300 mg of iodine per kilogram by using an optimized threshold. A trigger threshold of 100 HU at 120 kVp was used as a reference for comparison. Injected iodine doses and aortic CT numbers were compared among the three groups using Kruskal-Wallis test.Results: Ninety-six participants (mean age 6 standard deviation, 72 years 6 9; 80 men) were evaluated (32 participants in each group). The optimized threshold for VMIs at ...

show abstract

“…With CT images, it is always an inordinate challenge to select the optimal WW and WL setting for an atlas that incorporates the whole body. When interpreting CT images, radiologists optimize these window adjustments for tissues relevant to their task, and these alterations are crucial for the effective detection of some pathologies (Xue et al, 2012;Noda et al, 2018). Optimizing the presentation of any given region calls for a developed online atlas through where alterations could be made according to the viewer's This may be avoided by using a higher field strength MR scanner or utilizing prolonged image acquisition times (Westbrook & Talbot, 2018).…”

Section: Discussionmentioning

confidence: 99%

Creating a cross‐sectional, CT and MR atlas of the Pannon minipig

Petneházy

Donkó

Ellis

et al. 2021

Anat Histol Embryol

View full text Add to dashboard Cite

show abstract

Optimal window settings in single-source dual-energy computed tomography of the abdomen

Cited by 20 publications

References 15 publications

Comparison of radiation dose and image quality between fast kVp switching dual-energy CT and routine single-energy CT for whole abdomen at King Chulalongkorn Memorial Hospital

Comparison of radiation dose and image quality between fast kVp switching dual-energy CT and routine single-energy CT for whole abdomen at King Chulalongkorn Memorial Hospital

Optimized Bolus Threshold for Dual-Energy CT Angiography with Monoenergetic Images: A Randomized Clinical Trial

Creating a cross‐sectional, CT and MR atlas of the Pannon minipig

Contact Info

Product

Resources

About