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Objectives: The environmental footprint of iodinated contrast agents (ICAs) and gadolinium-based contrast agents (GBCAs) is noteworthy. This study assesses: (1) patients' "green sensitivity" as measured by their acceptance in a sustainability study and (2) the resulting potential reduction of contrast residuals in wastewater., Materials and Methods: After ethical approval, participants scheduled for administration of ICAs or GBCAs for diagnostic purposes were enrolled in this prospective observational study from July 2022 to October 2023. They were asked to prolong their hospital stay by up to 60 min to collect their first urine in dedicated canisters, thereby measuring the recovery rates of ICAs and GBCAs as found/theoretical ratio of concentrations. Mann-Whitney U, χ 2 tests, and multivariable regression analysis were used., Results: Patients scheduled for contrast-enhanced CT or MRI (n = 455) were screened; 422 (92.7%) accepted to participate. We enrolled 212 patients administered with ICAs and 210 administered with GBCAs. The median recovery rate was 51.2% (interquartile range 29.2-77.9%) for ICAs and 12.9% (9.0-19.3%) for GBCAs. At multivariable analysis, a significant effect of patient age (ICAs, p = 0.001; GBCAs, p = 0.014), urine volume (p < 0.001 for both), and time interval from contrast administration to urine collection (p < 0.001 for both) on recovery rates was found for both contrast agents; injected contrast volume (p = 0.046) and saline flushing usage (p = 0.008) showed a significant effect only for ICAs., Conclusion: The high patient enrollment compliance (93%) and potential recovery rates of 51% (ICAs) and 13% (GBCAs) play in favor of sustainable practices in reducing the environmental footprint of contrast agents., Key Points: Question How many patients are willing to extend their stay in radiology by up to 60 min to help reduce the environmental impact of contrast agents? Findings Over 90% of screened patients agreed to extend their stay by up to 60 min and collect their urine in dedicated containers. Clinical relevance Patients demonstrated a high willingness to cooperate in reducing the environmental impact of contrast agents, allowing for a potential recovery of approximately 51% for iodinated and 13% for gadolinium-based contrast agents., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: MRI-derived extracellular volume (ECV) allows characterization of myocardial changes before the onset of overt pathology, which may be caused by cancer therapy cardiotoxicity. Our purpose was to review studies exploring the role of MRI-derived ECV as an early cardiotoxicity biomarker to guide timely intervention., Materials and Methods: In April 2022, we performed a systematic search on EMBASE and PubMed for articles on MRI-derived ECV as a biomarker of cancer therapy cardiotoxicity. Two blinded researchers screened the retrieved articles, including those reporting ECV values at least 3 months from cardiotoxic treatment. Data extraction was performed for each article, including clinical and technical data, and ECV values. Pooled ECV was calculated using the random effects model and compared among different treatment regimens and among those who did or did not experience overt cardiac dysfunction. Meta-regression analyses were conducted to appraise which clinical or technical variables yielded a significant impact on ECV., Results: Overall, 19 studies were included. Study populations ranged from 9 to 236 patients, for a total of 1123 individuals, with an average age ranging from 12.5 to 74 years. Most studies included patients with breast or esophageal cancer, treated with anthracyclines and chest radiotherapy. Pooled ECV was 28.44% (95% confidence interval, CI, 26.85-30.03%) among subjects who had undergone cardiotoxic cancer therapy, versus 25.23% (95%CI 23.31-27.14%) among those who had not (p = .003)., Conclusion: A higher ECV in patients who underwent cardiotoxic treatment could imply subclinical changes in the myocardium, present even before overt cardiac pathology is detectable., Clinical Relevance Statement: The ability to detect subclinical changes in the myocardium displayed by ECV suggests its use as an early biomarker of cancer therapy-related cardiotoxicity., Key Points: • Cardiotoxicity is a common adverse effect of cancer therapy; therefore, its prompt detection could improve patient outcomes. • Pooled MRI-derived myocardial extracellular volume was higher in patients who underwent cardiotoxic cancer therapy than in those who did not (28.44% versus 25.23%, p = .003). • MRI-derived myocardial extracellular volume represents a potential early biomarker of cancer therapy cardiotoxicity., (© 2023. The Author(s).)

Objectives: To evaluate the diagnostic performance of dual-energy computed tomography (DECT) with regard to its post-processing techniques, namely linear blending (LB), iodine maps (IM), and virtual monoenergetic (VM) reconstructions, in diagnosing acute pulmonary embolism (PE)., Methods: This meta-analysis was conducted according to PRISMA. A systematic search on MEDLINE and EMBASE was performed in December 2019, looking for articles reporting the diagnostic performance of DECT on a per-patient level. Diagnostic performance meta-analyses were conducted grouping study parts according to DECT post-processing methods. Correlations between radiation or contrast dose and publication year were appraised., Results: Seventeen studies entered the analysis. Only lobar and segmental acute PE were considered, subsegmental acute PE being excluded from analysis due to data heterogeneity or lack of data. LB alone was assessed in 6 study parts accounting for 348 patients, showing a pooled sensitivity of 0.87 and pooled specificity of 0.93. LB and IM together were assessed in 14 study parts accounting for 1007 patients, with a pooled sensitivity of 0.89 and pooled specificity of 0.90. LB, IM, and VM together were assessed in 2 studies (for a total 144 patients) and showed a pooled sensitivity of 0.90 and pooled specificity of 0.90. The area under the curve for LB alone, and LB together with IM was 0.93 (not available for studies using LB, IM and VM because of paucity of data). Radiation and contrast dose did not decrease with increasing year of publication., Conclusions: Considering the published performance of single-energy CT in diagnosing acute PE, either dual-energy or single-energy computed tomography can be comparably used for the detection of acute PE., Key Points: • Dual-energy CT displayed pooled sensitivity and specificity of 0.87 and 0.93 for linear blending alone, 0.89 and 0.90 for linear blending and iodine maps, and 0.90 and 0.90 for linear blending iodine maps, and virtual monoenergetic reconstructions. • The performance of dual-energy CT for patient management is not superior to that reported in literature for single-energy CT (0.83 sensitivity and 0.96 specificity). • Dual-energy CT did not yield substantial advantages in the identification of patients with acute pulmonary embolism compared to single-energy techniques., (© 2021. European Society of Radiology.)

Objectives: To estimate the MRI-derived myocardial extracellular volume (ECV) in healthy subjects together with reference normality interval., Methods: The study was registered on PROSPERO and reported according to PRISMA. In October 2017, a systematic search (MEDLINE/EMBASE) was performed for articles reporting MRI-derived ECV in healthy subjects. The pooled ECV (pECV) with 95% confidence interval (CI) was calculated using the random-effect model; the normality interval was calculated as pECV ± 2 root mean square of all study standard deviations. The Newcastle-Ottawa scale was used for assessing study quality, subgroup/meta-regression analyses for technical/biological covariates, and Egger test for publication bias risk., Results: Of 282 articles, 56 were analyzed totaling 1851 subjects with age 16-68 years, body mass index 23-28 kg/m 2 , and left ventricular ejection fraction 58-74%. Contrast dose varied from 0.075 to 0.200 mmol/kg. Heterogeneity was high (I 2  = 92%). The pECV was 25.6% (95% CI 25.2-26.0%) with a normality interval of 19.6-31.6%. pECV was slightly increasing with age (β = 0.03%, p = 0.038) and slightly decreasing with the percentage of males (β = - 0.02%, p = 0.053). Sequence type significantly (p = 0.003) impacted on pECV: the normal interval was 19.9-31.9% for MOLLI and 20.3-33.5% for ShMOLLI. Contrast type/dose, time of acquisition, and magnetic field strength did not significantly impact pECV (p > 0.093). Quality was moderate or high in 48/56 studies (86%). No risk of publication bias (p = 0.728)., Conclusions: Myocardial pECV in healthy subjects was 25.6%, increasing by 0.03% for each year of age. The ECV normality interval was 19.9-31.9% for MOLLI and 20.3-33.5% for ShMOLLI., Key Points: • The pooled estimate of normal MRI-derived ECV based on 1851 subjects was 25.6%, slightly increasing with age and slightly decreasing with the percentage of males. • MRI-derived ECV was independent of contrast type/dose and field strength but dependent on the imaging sequence. • The modeled normality reference interval of MRI-derived ECV was 19.9-31.9% for the MOLLI sequence and 20.3-33.5% for the ShMOLLI sequence.

Objectives: To estimate the impact of endoaortic stents/mechanical heart valves on the output of an automatic exposure control (AEC) system and CT radiation dose., Methods: In this phantom study, seven stents and two valves were scanned with varying tube voltage (80/100/120 kVp), AEC activation (enabled/disabled) and prosthesis (present/absent), for a total of 540 scans. For each prosthesis, the dose-length product (DLP) was compared between scans with the AEC enabled and disabled. Percentage confidence levels for differences due to the prosthesis were calculated., Results: Differences between results with the AEC enabled and disabled were not statistically significant (p ≥ 0.059). In the comparison with and without the prosthesis, DLP was unchanged at 80 kVp and 100 kVp, while a slight increase was observed at 120 kVp. The radiation dose varied from 1.8 mGy to 2.4 mGy without the prosthesis and from 1.8 mGy to 2.5 mGy with the prosthesis (confidence level 37-100%)., Conclusions: The effect of the prosthesis on the AEC system was negligible and not clinically relevant. Therefore, disabling the AEC system when scanning these patients is not likely to provide a benefit., Key Points: • CT-AEC system is not impaired in patients with endoaortic prostheses/heart valves. • Negligible differences may be observed only at 120 kVp. • Disabling the AEC system in these patients is not recommended.