Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT

Solbak, Marian S.; Henning, Mette Karen; England, Andrew; Martinsen, Anne Catrine Trægde; Aaløkken, Trond Mogens; Johansen, Safora

doi:10.1186/s41747-020-00184-z

Cited by 20 publications

(14 citation statements)

References 41 publications

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“…Iodine is an alternative candidate that exhibits a broad antibacterial spectrum and has been used as a skin disinfectant for a long time [36]. In other aspects, iodine is an essential element in the living body and is utilized in catheter angiograms at high concentrations (300 mg I/mL and above) in vivo [37], demonstrating the cytocompatibility of iodine. A few reports demonstrate iodine being introduced into metal surfaces.…”

Section: Introductionmentioning

confidence: 99%

Iodine-Loaded Calcium Titanate for Bone Repair with Sustainable Antibacterial Activity Prepared by Solution and Heat Treatment

Yamaguchi

Shintani

et al. 2021

Nanomaterials

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In the orthopedic and dental fields, simultaneously conferring titanium (Ti) and its alloy implants with antibacterial and bone-bonding capabilities is an outstanding challenge. In the present study, we developed a novel combined solution and heat treatment that controllably incorporates 0.7% to 10.5% of iodine into Ti and its alloys by ion exchange with calcium ions in a bioactive calcium titanate. The treated metals formed iodine-containing calcium-deficient calcium titanate with abundant Ti-OH groups on their surfaces. High-resolution XPS analysis revealed that the incorporated iodine ions were mainly positively charged. The surface treatment also induced a shift in the isoelectric point toward a higher pH, which indicated a prevalence of basic surface functionalities. The Ti loaded with 8.6% iodine slowly released 5.6 ppm of iodine over 90 days and exhibited strong antibacterial activity (reduction rate >99%) against methicillin-resistant Staphylococcus aureus (MRSA), S. aureus, Escherichia coli, and S. epidermidis. A long-term stability test of the antibacterial activity on MRSA showed that the treated Ti maintained a >99% reduction until 3 months, and then it gradually decreased after 6 months (to a 97.3% reduction). There was no cytotoxicity in MC3T3-E1 or L929 cells, whereas apatite formed on the treated metal in a simulated body fluid within 3 days. It is expected that the iodine-carrying Ti and its alloys will be particularly useful for orthopedic and dental implants since they reliably bond to bone and prevent infection owing to their apatite formation, cytocompatibility, and sustainable antibacterial activity.

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Section: Introductionmentioning

confidence: 99%

Iodine-Loaded Calcium Titanate for Bone Repair with Sustainable Antibacterial Activity Prepared by Solution and Heat Treatment

Yamaguchi

Shintani

et al. 2021

Nanomaterials

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“…However, the majority (56%) of the respondents used flexible kV strategies. The use of lower kVp has been reported to reduce both radiation dose and CM load in chest CT, while maintaining image quality (50,51). Especially for vascular CT examinations, lower kVp settings are advantageous as higher noise is counterbalanced by higher vascular attenuation (52).…”

Section: Discussionmentioning

confidence: 99%

Contrast medium protocols in routine chest CT: a survey study

2021

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Background Administration of contrast medium (CM) is an important image quality factor in computed tomography (CT) of the chest. There is no clear evidence or guidelines on CM strategies for chest CT, thus a consensus approach is needed. Purpose To survey the potential impact on differences in chest CT protocols, with emphasis on strategies for the administration of CM. Material and Methods A total of 170 respondents were included in this survey, which used two different approaches: (i) an online survey was sent to the members of the European Society of Thoracic Imaging (ESTI); and (ii) an email requesting a copy of their CT protocol was sent to all hospitals in Norway, and university hospitals in Sweden and Denmark. The survey focused on factors affecting CM protocols and enhancement in chest CT. Results The overall response rate was 24% (n = 170): 76% of the respondents used a CM concentration of ≥350 mgI/mL; 52% of the respondents used a fixed CM volume strategy. Fixed strategies for injection rate and delay were also the most common approach, practiced by 73% and 57% of the respondents, respectively. The fixed delay was in the range of 20–90 s. Of the respondents, 56% used flexible tube potential strategies (kV). Conclusion The chest CT protocols and CM administration strategies employed by the respondents vary widely, affecting the image quality. The results of this study underline the need for further research and consensus guidelines related to chest CT.

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“…The FD of the eciFD protocol is likely to change with the use of saline flushes [ 29 , 30 ] and the CM dose may be reduced. [ 2 , 10 ]…”

Section: Limitationsmentioning

confidence: 99%

Proposal of a novel protocol using estimated cardiac index fractional dose to improve aortic contrast enhancement for early-phase dynamic CT

et al. 2022

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Maximum aortic computed tomography value (CTV) is difficult to control because of variations in cardiac function and patient physique. Therefore, to improve early-phase aortic enhancement on dynamic computed tomography (CT), we developed an estimated cardiac index fractional dose (eciFD). The eciFD protocol is a novel and original protocol for administering fractional dose (FD), representing the amount of iodine per unit body weight per injection duration, based on cardiac index (cardiac output divided by body surface area) as estimated by age in early-phase dynamic CT. At the time of administration, by selecting FD based on the patient's age and selecting a parameter that can achieve this FD, an aortic CTV ≥300 HU (ACTV≥300) can be obtained. This study aimed to investigate aortic enhancement on CT angiography using the eciFD protocol.This retrospective study investigated 291 consecutive patients who underwent dynamic CT from neck to abdomen after recommendation of the eciFD protocol at our institution. We compared early-phase aortic CTV distributions by scan delay between an eciFD group (eciFD applied, n = 135) and a non-eciFD group (eciFD not applied, n = 80). The effect of eciFD on early-phase ACTV≥300 was evaluated using logistic regression analysis adjusted for several potentially meaningful clinical confounders related to aortic CTV, namely male sex, heart rate ≤80 beats/min, estimated glomerular filtration rate ≤40 mL/min, use of eciFD, bolus tracking (BT), history of myocardial infarction, and order from the emergency center.The eciFD protocol was a significant factor for early-phase ACTV≥300 after adjusting for several confounders (odds ratio 3.03; 95% confidence intervals 1.59–5.77; P = .001). No interaction was seen between BT and eciFD protocol (p for interaction = 0.76). In terms of CTV distribution, with both a fixed scan delay time and BT, the eciFD group showed a high aortic CTV. The combination of eciFD protocol with BT provided a particularly high percentage of patients with ACTV≥300 (86.4%).The eciFD protocol was useful for improving aortic contrast enhancement. These findings need to be validated in a randomized controlled study.

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Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT

Cited by 20 publications

References 41 publications

Iodine-Loaded Calcium Titanate for Bone Repair with Sustainable Antibacterial Activity Prepared by Solution and Heat Treatment

Iodine-Loaded Calcium Titanate for Bone Repair with Sustainable Antibacterial Activity Prepared by Solution and Heat Treatment

Contrast medium protocols in routine chest CT: a survey study

Proposal of a novel protocol using estimated cardiac index fractional dose to improve aortic contrast enhancement for early-phase dynamic CT

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