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BACKGROUND: We prospectively assessed the reproducibility of a novel low-dose single-volume dynamic computed tomography (CT) myocardial blood flow measurement technique. METHODS: Thirty-four pairs of measurements were made under rest and stress conditions in 13 swine (54.3 ± 12.3 kg). One or two acquisition pairs were acquired in each animal with a 10-min delay between each pair. Contrast (370 mgI/mL; 0.5 mL/kg) and a diluted contrast/saline chaser (0.5 mL/kg; 30:70 contrast/saline) were injected peripherally at 5 mL/s, followed by bolus tracking and acquisition of a single volume scan (100 kVp; 200 mA) with a 320-slice CT scanner. Bolus tracking and single volume scan data were used to derive perfusion in mL/min/g using a first-pass analysis model; the coronary perfusion territories of the left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA) were automatically assigned using a previously validated minimum-cost path technique. The reproducibility of CT myocardial perfusion measurement within the LAD, LCx, RCA, and the whole myocardium was assessed via regression analysis. The average CT dose index (CTDI) of perfusion measurement was recorded. RESULTS: The repeated first (Pmyo1) and second (Pmyo2) single-volume CT perfusion measurements were related by Pmyo2 = 1.01Pmyo1 - 0.03(ρ = 0.96; RMSE = 0.08 mL/min/g; RMSE = 0.07 mL/min/g) for the whole myocardium, and by Preg2 = 0.86Preg1 + 0.13(ρ = 0.87; RMSE = 0.31 mL/min/g; RMSE = 0.29 mL/min/g) for the LAD, LCx, and RCA perfusion territories. The average CTDI of the single-volume CT perfusion measurement was 10.5 mGy. CONCLUSION: The single-volume CT blood flow measurement technique provides reproducible low-dose myocardial perfusion measurement using only bolus tracking data and a single whole-heart volume scan. RELEVANCE STATEMENT: The single-volume CT blood flow measurement technique is a noninvasive tool that reproducibly measures myocardial perfusion and provides coronary CT angiograms, allowing for simultaneous anatomic-physiologic assessment of myocardial ischemia. KEY POINTS: A low-dose single-volume dynamic CT myocardial blood flow measurement technique is reproducible. Motion misregistration artifacts are eliminated using a single-volume CT perfusion technique. This technique enables combined anatomic-physiologic assessment of coronary artery disease.

SIGNIFICANCE: Fluorescent organic dyes provide imaging capabilities at cellular and sub-cellular levels. However, a common problem associated with some of the existing dyes such as the US FDA-approved indocyanine green (ICG) is their weak fluorescence emission. Alternative dyes with greater emission characteristics would be useful in various imaging applications. Complementing optical imaging, magnetic resonance (MR) imaging enables deep tissue imaging. Nano-sized delivery systems containing dyes with greater fluorescence emission as well as MR contrast agents present a promising dual-mode platform with high optical sensitivity and deep tissue imaging for image-guided surgical applications. AIM: We have engineered a nano-sized platform, derived from erythrocyte ghosts (EGs), with dual near-infrared fluorescence and MR characteristics by co-encapsulation of a brominated carbocyanine dye and gadobenate dimeglumine (Gd-BOPTA). APPROACH: We have investigated the use of three brominated carbocyanine dyes (referred to as BrCy106, BrCy111, and BrCy112) with various degrees of bromination, structural symmetry, and acidic modifications for encapsulation by nano-sized EGs (nEGs) and compared their resulting optical characteristics with nEGs containing ICG. RESULTS: We find that asymmetric dyes (BrCy106 and BrCy112) with one dibromobenzene ring offer greater fluorescence emission characteristics. For example, the relative fluorescence quantum yield ( ϕ ) for nEGs fabricated using 100    μ M of BrCy112 is ∼ 41 -fold higher than nEGs fabricated using the same concentrations of ICG. The dual-mode nEGs containing BrCy112 and Gd-BOPTA show a nearly twofold increase in their ϕ as compared with their single optical mode counterpart. Cytotoxicity is not observed upon incubation of SKOV3 cells with nEGs containing BrCy112. CONCLUSIONS: Erythrocyte nano-ghosts with dual optical and MR characteristics may ultimately prove useful in various biomedical imaging applications such as image-guided tumor surgery where MR imaging can be used for tumor staging and mapping, and fluorescence imaging can help visualize small tumor nodules for resection.

OBJECTIVE: Increased subcutaneous and visceral adipose tissue (SAT/VAT) volume is associated with risk for cardiometabolic diseases. This work aimed to develop and evaluate automated abdominal SAT/VAT segmentation on longitudinal MRI in adults with overweight/obesity using attention-based competitive dense (ACD) 3D U-Net and 3D nnU-Net with full field-of-view volumetric multi-contrast inputs. MATERIALS AND METHODS: 920 adults with overweight/obesity were scanned twice at multiple 3 T MRI scanners and institutions. The first scan was divided into training/validation/testing sets (n = 646/92/182). The second scan from the subjects in the testing set was used to evaluate the generalizability for longitudinal analysis. Segmentation performance was assessed by measuring Dice scores (DICE-SAT, DICE-VAT), false negatives (FN), and false positives (FP). Volume agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS: ACD 3D U-Net achieved rapid ( 0.997) in longitudinal analysis. DISCUSSION: ACD 3D U-Net and 3D nnU-Net can be automated tools to quantify abdominal SAT/VAT volume rapidly, accurately, and longitudinally in adults with overweight/obesity.

BACKGROUND: Global shortages of iodinated contrast media (ICM) during COVID-19 pandemic forced the imaging community to use ICM more strategically in CT exams. PURPOSE: The purpose of this work is to provide a quantitative framework for preserving iodine CNR while reducing ICM dosage by either lowering kV in single-energy CT (SECT) or using lower energy virtual monochromatic images (VMI) from dual-energy CT (DECT) in a phantom study. MATERIALS AND METHODS: In SECT study, phantoms with effective diameters of 9.7, 15.9, 21.1, and 28.5 cm were scanned on SECT scanners of two different manufacturers at a range of tube voltages. Statistical based iterative reconstruction and deep learning reconstruction were used. In DECT study, phantoms with effective diameters of 20, 29.5, 34.6, and 39.7 cm were scanned on DECT scanners from three different manufacturers. VMIs were created from 40 to 140 keV. ICM reduction by lowering kV levels for SECT or switching from SECT to DECT was calculated based on the linear relationship between iodine CNR and its concentration under different scanning conditions. RESULTS: On SECT scanner A, while matching CNR at 120 kV, ICM reductions of 21%, 58%, and 72% were achieved at 100, 80, and 70 kV, respectively. On SECT scanner B, 27% and 80% ICM reduction was obtained at 80 and 100 kV. On the Fast-kV switch DECT, with CNR matched at 120 kV, ICM reductions were 35%, 30%, 23%, and 15% with VMIs at 40, 50, 60, and 68 keV, respectively. On the dual-source DECT, ICM reductions were 52%, 48%, 42%, 33%, and 22% with VMIs at 40, 50, 60, 70, and 80 keV. On the dual-layer DECT, ICM reductions were 74%, 62%, 45%, and 22% with VMIs at 40, 50, 60, and 70 keV. CONCLUSIONS: Our work provided a quantitative baseline for other institutions to further optimize their scanning protocols to reduce the use of ICM.

ObjectiveTo determine the feasibility and biologic correlations of dynamic susceptibility contrast (DSC), dynamic contrast enhanced (DCE), and quantitative maps derived from contrast leakage effects obtained simultaneously in gliomas using dynamic spin-and-gradient-echo echoplanar imaging (dynamic SAGE-EPI) during a single contrast injection.Materials and methodsThirty-eight patients with enhancing brain gliomas were prospectively imaged with dynamic SAGE-EPI, which was processed to compute traditional DSC metrics (normalized relative cerebral blood flow [nrCBV], percentage of signal recovery [PSR]), DCE metrics (volume transfer constant [Ktrans], extravascular compartment [ve]), and leakage effect metrics: ΔR2,ss* (reflecting T2*-leakage effects), ΔR1,ss (reflecting T1-leakage effects), and the transverse relaxivity at tracer equilibrium (TRATE, reflecting the balance between ΔR2,ss* and ΔR1,ss). These metrics were compared between patient subgroups (treatment-naïve [TN] vs recurrent [R]) and biological features (IDH status, Ki67 expression).ResultsIn IDH wild-type gliomas (IDHwt-i.e., glioblastomas), previous exposure to treatment determined lower TRATE (p = 0.002), as well as higher PSR (p = 0.006), Ktrans (p = 0.17), ΔR1,ss (p = 0.035), ve (p = 0.006), and ADC (p = 0.016). In IDH-mutant gliomas (IDHm), previous treatment determined higher Ktrans and ΔR1,ss (p = 0.026). In TN-gliomas, dynamic SAGE-EPI metrics tended to be influenced by IDH status (p ranging 0.09-0.14). TRATE values above 142 mM-1s-1 were exclusively seen in TN-IDHwt, and, in TN-gliomas, this cutoff had 89% sensitivity and 80% specificity as a predictor of Ki67 > 10%.ConclusionsDynamic SAGE-EPI enables simultaneous quantification of brain tumor perfusion and permeability, as well as mapping of novel metrics related to cytoarchitecture (TRATE) and blood-brain barrier disruption (ΔR1,ss), with a single contrast injection.Clinical relevance statementSimultaneous DSC and DCE analysis with dynamic SAGE-EPI reduces scanning time and contrast dose, respectively alleviating concerns about imaging protocol length and gadolinium adverse effects and accumulation, while providing novel leakage effect metrics reflecting blood-brain barrier disruption and tumor tissue cytoarchitecture.Key points• Traditionally, perfusion and permeability imaging for brain tumors requires two separate contrast injections and acquisitions. • Dynamic spin-and-gradient-echo echoplanar imaging enables simultaneous perfusion and permeability imaging. • Dynamic spin-and-gradient-echo echoplanar imaging provides new image contrasts reflecting blood-brain barrier disruption and cytoarchitecture characteristics.

Purpose: Solutions of iodine-based compounds, due to their high X-ray attenuation coefficient, are widely used as contrast agents in computed tomography (CT) imaging. This paper investigates the attenuation properties of iodine and gold to develop nanoparticle-based contrast agents, for example, composite nanoparticles (NPs) with layers of iodine and gold or a mixture of NPs of gold and iodine. Materials and Methods: A theoretical formula is derived that gives the Hounsfield Unit (HU) for different weight-by-weight (w/w) concentrations of a mixture of blood + iodine + gold. The range of compositions for which iodine + gold mixture can give a suitable HU ≥250 upon being mixed with blood, is formulated. These estimates are derived from experiments on the variation of HU values in different compositions of aqueous solutions of iodine and available data for gold. Results: It is seen that for an aqueous solution of iodine, the suitable HU of 250 (hence giving sufficient gray level to the CT image) can be obtained with w/w concentrations of iodine being 0.0044, 0.008, and 0.0097 for observations at 80, 100, and 120 kVp, respectively. The corresponding w/w concentrations of gold NPs would be 0.0103, 0.0131, and 0.0158. With these basic results, compositions of suitable mixtures of iodine and gold are also specified. Conclusion: Aqueous suspensions of gold NPs are suitable as contrast materials for CT imaging and can also be used as a component of a composite contrast material consisting of an iodine and gold mixture. Keywords: Computed tomography, contrast agent, nanoparticles, Author(s): Rezvan Ravanfar Haghighi (corresponding author) [1]; Fariba Zarei [1,2]; Samira Moshiri [1]; Anahita Jafari [1]; Sabyasachi Chatterjee [3]; Vyas Akondi [4]; Vani Vardhan Chatterjee [5] INTRODUCTION Computed tomography (CT) [...]

Introduction: Cancer tissue absorbs 3-8 times more glucose than normal tissue. Therefore, we developed a gadobutrol-glucose solution for 7.0T magnetic resonance imaging to visualize whole cancerous regions at high contrast. Methods: The contrast medium consists of gadobutrol and glucose solutions, and these solutions are mixed before the vein infusion. We used readily available solutions, and the concentrations of the gadobutrol and glucose solutions were 60% and 5.0%, respectively. To visualize the cancerous region, we used two rabbits with VX7 thigh cancer. First, vein injection was carried out using a gadobutrol-saline solution containing 0.3 ml gadobutrol, and T1-weighted imaging (T1WI) was performed. Twenty-four hours after the first experiment, we performed T1WI of the VX7-cancer region using 50.3 mL gadobutrol-glucose solution including 0.3 ml gadobutrol. Results: Compared with T1WI using the gadobutrol-saline solution, the signal intensity of the cancerous region substantially increased using the gadobutrol-glucose solution. Conclusion: We confirmed significant signal-intensity increases in the whole VX7-cancer region of a rabbit thigh utilizing vein infusion of gadobutrol-glucose solution since the gadobutrol molecules were absorbed throughout the cancerous region along with glucose molecules. Keywords: 7.0T magnetic resonance imaging, angiographic effect, cancer visualization, gadobutrol glucose, hypoxic cancer, T1-weighted imaging, Author(s): Manabu Watanabe [1]; Eiichi Sato (corresponding author) [2]; Jiro Sato [1]; Kazuki Ito [1]; Hodaka Moriyama [1]; Osahiko Hagiwara [1]; Toshiyuki Enomoto [1]; Ryoko Yoshida [3]; Susumu Hayakawa [3]; [...]

PURPOSE: Left ventricular (LV) fibrosis has a key role in arrhythmogenesis in patients with mitral valve prolapse (MVP). Cardiac magnetic resonance identifies LV fibrosis by using late gadolinium enhancement (LGE) technique. LGE assessment and quantification in patients with MVP lacks of standardization protocols. METHODS: 66 MVP patients with normal systolic function and without significant regurgitation were enrolled. Semi-automated gray-scale thresholding techniques using full width at half maximum (FWHM) and 2, 3 and 5 standard deviation (SD) above the remote myocardium were used and compared with the visual assessment, considered as the gold standard. RESULTS: LGE was identified in 41 MVP patients (62%) and quantified. The mean quantity of LGE visually assessed was 2.40 ± 1.07% or 1.40 ± 0.82 g. With FWHM, LGE resulted 3.56 ± 1.23% or 1.99 ± 1.13 g. Using thresholding, the mean LGE quantity was 9.2 ± 3.1% or 4.82 ± 2.28 g for 2-SD, 5.72 ± 1.75% or 3.06 ± 1.47 g for 3-SD and 2.36 ± 0.99% or 1.29 ± 0.79 g for 5-SD. The 5-SD measurement in percentage demonstrated a good correlation with LGE quantification visually assessed (2.40 ± 1.07 vs. 2.363 ± 0.9909, p = 0.543). When compared with the gold standard, the 5-SD threshold quantification, both in percentage and in grams, revealed the least intra-observer (respectively, ICC: 0.976 and 0.966) and inter-observer variability (respectively ICC: 0.948 and 0.935). CONCLUSION: The 5-SD gray-scale threshold technique in percentage revealed the best correlation with the visual assessment and an optimal reproducibility in MVP patient.

Contrast transport models are widely used to quantify blood flow and transport in dynamic contrast-enhanced magnetic resonance imaging. These models analyze the time course of the contrast agent concentration, providing diagnostic and prognostic value for many biological systems. Thus, ensuring accuracy and repeatability of the model parameter estimation is a fundamental concern. In this work, we analyze the structural and practical identifiability of a class of nested compartment models pervasively used in analysis of MRI data. We combine artificial and real data to study the role of noise in model parameter estimation. We observe that although all the models are structurally identifiable, practical identifiability strongly depends on the data characteristics. We analyze the impact of increasing data noise on parameter identifiability and show how the latter can be recovered with increased data quality. To complete the analysis, we show that the results do not depend on specific tissue characteristics or the type of enhancement patterns of contrast agent signal.

IntroductionSmall bowel obstruction (SBO) is one of the most common causes for hospital admission in Ethiopia. The use of water-soluble contrast agents (WSCAs) such as Gastrografin to manage adhesive SBO can predict nonoperative resolution of SBO and reduce decision time to surgery and length of hospital stay. However, nothing is known about practice patterns and Gastrografin use in low-income settings. We sought to characterize current management practices, including use of WSCAs, as well as outcomes for patients with SBO in Addis Ababa, Ethiopia.MethodsWe conducted a mixed-methods study consisting of a survey of surgeons throughout Ethiopia and a retrospective record review at five public, tertiary care-level teaching hospitals in Addis Ababa.ResultsOf the 76 surgeons who completed the survey, 63% had heard of the use of WSCAs for SBO and only 11% used oral agents for its management. Chart review of 149 patients admitted with SBO showed the most common etiology was adhesion (39.6% of admissions), followed by small bowel volvulus (20.8%). Most patients (83.2%) underwent surgery during their admission. The most common diagnosis in patients who did not require surgery was also adhesion (68.0%), as well as for those who had surgery (33.9%), followed by small bowel volvulus (24.2%).ConclusionsThe etiology of SBO in Ethiopia may be changing, with postoperative adhesions becoming more common than other historically more prevalent causes. Although a Gastrografin protocol as a diagnostic and potentially therapeutic aid for SBO is feasible in this population and setting, challenges can be anticipated, and future studies of protocol implementation and effectiveness are needed to further inform its utility in Ethiopia and other low-income and middle-income countries.

The synthesis and characterization of a gadolinium-based contrast agent conjugated to 3-phosphoglycerate (Gd-3PG) are reported. The synthetic steps are optimized to incorporate a selective deprotection strategy for a primary tert-butyl dimethyl silyl (TBS) hydroxyl over a secondary one. The relaxivity of Gd-3PG shows characteristic improvement, likely due to secondary sphere effects and/or an increase in molecular weight (5.39 ± 0.14 mM−1 s−1 at 1.4 T and 37 °C). Michaelis–Menten enzymatic kinetics was measured on the modified 3PG-arm and it showed similar activity to the native 3PG metabolite, Km = 240 ± 30 μM. This agent and future versions of this type of GBCA, which are conjugated to glycolytic metabolites, were designed to monitor in vivo allosteric regulatory events in glycolytic processes. [ABSTRACT FROM AUTHOR]

We present here a user-friendly calculator for the setting of a pediatric split-bolus polytrauma computed tomography (CT) protocol with a mixed arterial and venous phase, aiming to both reduce radiation dose and improve workflow while assuring optimal image quality. All the different parameters are calculated based on patient's weight with rapid computation of the injected contrast media and saline volumes, injection's flow rate, injection's timing, and optimal acquisition time. The designed calculator is built in a widely available Google Sheets file, accessible by a quick response (QR) code. Although polytrauma imaging represents the main goal of the technique, it can be used in a wide variety of contexts, including oncological, infectious, and vascular pathologies. [ABSTRACT FROM AUTHOR]

Background: Photon counting detector (PCD) CT benefits from reduced noise compared with conventional energy-integrating detector (EID) CT, which should translate to improved image quality and reduced radiation exposure for pediatric patients undergoing chest CT with IV contrast. Objective: To determine the differences in radiation exposure and image quality of PCD CT and EID CT in pediatric chest CT with intravenous (IV) contrast. Materials and methods: In this institutional review board–approved retrospective observational study, 20 scan pairs (20 PCD CT; 20 EID CT) for children who underwent chest CT with IV contrast on both a PCD CT (Siemens NAEOTOM Alpha) and an EID CT (Siemens SOMATOM Definition Edge or Force) within 12 months were reviewed independently by three pediatric radiologists for three subjective quality features on 5-point Likert scales: overall quality, small structure delineation, and motion artifact. Objective measures of image quality (image noise, signal-to-noise ratio, and contrast-to-noise ratio) were assessed by a single radiologist in several locations in the chest through region of interest measurement of Hounsfield units (HU) and standard deviation. Patient-related and radiation exposure parameters were collected for each scan and summarized with median and interquartile range (IQR). The Wilcoxon rank-sum test was utilized to compare groups. A P < 0.05 indicated statistical significance. Inter-observer agreement of subjective image quality metrics was analyzed using weighted kappa. Results: Age (14.2 years vs 13.8 years, P= 0.15), height (P= 0.13), weight (P= 0.21), and BMI (P = 0.24) did not significantly differ between groups. There were 10 male and 3 female patients. Compared to EID CT, PCD CT showed lower radiation exposure parameters including volumetric CT dose index, 1.7 mGy (IQR 1.1–2.4 mGy) vs 3.8 mGy (IQR 2.0–4.7 mGy) (P< 0.01), and size-specific dose estimate, 2.6 mGy (IQR 1.8–3.1 mGy) vs 5.0 mGy (IQR 3.3–6.2 mGy) (P< 0.01). Objective image quality of lung parenchyma was improved on the PCD CT scanner, including image noise 119.5 HU (IQR 95.4–135.7 HU) vs 143.1 HU (IQR 125.4–169.8 HU) (P < 0.01), signal-to-noise ratio (SNR) -6.1 (IQR -8.4 to -4.8) vs -4.9 (IQR -5.6 to -3.8) (P= 0.01), and contrast-to-noise ratio -63.9 (-84.1 to -57.5) vs -60.5 (-76.3 to -52.5) (P = 0.01). Motion artifact was improved on the PCD CT scanner (P< 0.01). No significant differences in overall image quality or small structure delineation were identified (P= 0.06 and P= 0.31). Conclusion: PCD CT pediatric chest CT had significantly reduced radiation exposure, improved image quality, and reduced motion artifact compared with EID CT. [ABSTRACT FROM AUTHOR]

Contrast-induced acute kidney injury (CI-AKI) is one of the main causes of hospital-acquired renal failure, and still lacks of effective treatments. Previously, we demonstrated that αKlotho, which is an anti-aging protein that highly expresses in the kidney, has therapeutic activity in CI-AKI through promoting autophagy. However, the specific mechanism underlying αKlotho-mediated autophagy remains unclear. The RNA sequencing analysis of renal cortex revealed that the differentially expressed genes related to autophagy between αKlotho-treated CI-AKI mice and vehicle-treated CI-AKI mice were found to be associated with mitophagy and apoptosis. In the kidney of CI-AKI mice and HK-2 cells exposed to Iohexol, we revealed that αKlotho promoted mitophagy and decreased cell apoptosis. Mechanistically, αKlotho attenuated mitochondria damage, decreased mitochondrial ROS by upregulating BNIP3-mediated mitophagy. BNIP3 deletion abolished the beneficial effects of αKlotho both in vivo and in vitro. Moreover, we further demonstrated that αKlotho upregulated FoxO3 nuclear expression in Iohexol-treated HK-2 cells. Knockdown of FOXO3 gene inhibited αKlotho-promoted BNIP3-mediated mitophagy and subsequently increased the oxidative injury and cell apoptosis. Taken together, our results indicated a critical role of αKlotho in alleviating CI-AKI via mitophagy promotion involving the FoxO3-BNIP3 pathway. [ABSTRACT FROM AUTHOR]

The interest in the applications of upconverting luminescent nanomaterials has expanded significantly, particularly in the biomedical field. An opportunity for innovation in this realm lies in the development of multimodal contrast agents that exhibit both luminescent and magnetic responses. This study presents an easily reproducible strategy for the solvothermal synthesis of NaYF 4 :Yb3+,Ln3+@NaGdF 4 (Ln = Er3+ or Tm3+) core@shell nanoparticles. The shell incorporation process initially involved dissolving the outer layer of NaYF 4 :Yb3+,Ln3+ cores, followed by the radial growth of NaGdF 4 around them. This shell provides intense paramagnetic properties without affecting the luminescent response of the cores. The optimized process yielded individual core@shell nanoparticles, with average diameters of 20 ± 5 nm for NaYF 4 :Yb3+,Er3+@NaGdF 4 and 19 ± 3 nm for NaYF 4 :Yb3+,Tm3+@NaGdF 4 UCNPs. The presence of NaGdF 4 shells was further confirmed by Raman spectroscopy, which revealed a change in polarizability within the structure due to the presence of Gd3+ instead of Y3+. Based on the hysteresis loops, the magnetic response of NaYF 4 :Yb3+,Ln3+ was negligible, whereas NaYF 4 :Yb3+,Ln3+@NaGdF 4 exhibited saturation at 1.04 emu/g at 20 kOe. Compared to common thermal decomposition approaches, this method offers several advantages: it provides nanoparticles that are colloidally stable in aqueous solutions, a higher reaction yield, eliminates the need for an inert atmosphere, reduces the excessive use of solvents for separation and washing, and requires less experimental manipulation. Therefore, this method enables the synthesis of materials with applications in the development of sensors, contrast agents, or theranostic tools with dual magnetic-luminescent responses. [ABSTRACT FROM AUTHOR]

Summary This study aims to examine and compare the effectiveness of dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) and Digital Subtraction Angiography (DSA) in evaluating hypervascular spinal metastases. A comprehensive literature review was conducted, utilizing top‐tier databases such as PubMed, Scopus and Google Scholar, to compile an authoritative and up‐to‐date overview of the current advancements in the field. We synthesized key studies focusing on the advantages, limitations and efficacy of both imaging techniques. DCE‐MRI provides a non‐invasive method for evaluating tissue morphology, perfusion and vascularity, offering valuable information for cancer diagnosis and treatment monitoring. In contrast, DSA is an invasive procedure primarily used for embolization and diagnosing cerebrovascular events. Both modalities have distinct features regarding image acquisition, contrast agents, resolution and accessibility. DCE‐MRI shows promise for cancer‐related applications, offering advantages over conventional MRI by incorporating anatomical and hemodynamic parameters. While DSA remains important for cases requiring critical vascular information, further research is necessary to explore its potential therapeutic benefits in assessing vessel patency. Continued investigations are crucial to uncover additional insights and therapeutic applications for both DCE‐MRI and DSA in medical imaging. [ABSTRACT FROM AUTHOR]

Contrast-enhanced ultrasonography (CEUS) has revolutionized diagnostic imaging by significantly improving the accuracy and capabilities of ultrasound technology. By utilizing contrast agents, CEUS offers enhanced visualization of blood flow, superior detection of vascular diseases, and delineation of pathological from healthy tissues. Real-time imaging capabilities afforded by CEUS have been shown to be instrumental in guiding interventions and assessing treatment efficacy, thereby contributing to personalized patient care and improved clinical outcomes. This document provides a comprehensive review of the current benefits, limitations, and future directions of contrast-enhanced ultrasonography. It acknowledges the potential for allergic reactions, the necessity for specialized training, high costs, and the occurrence of image artifacts as drawbacks, while also anticipating advancements in targeted agents and imaging techniques. Moreover, the document emphasizes the need for ongoing research to evaluate the long-term safety and efficacy of contrast agents and their impact across various medical disciplines. Despite the challenges, the integration of CEUS into clinical practice holds enormous potential to further refine diagnostic processes and enhance patient management. [ABSTRACT FROM AUTHOR]

Background: Anaphylaxis is a serious allergic reaction that has a rapid onset and can result in death. Identifying the factors that trigger anaphylaxis and increase its severity is important for preventing refractory anaphylaxis (RA). In this study, we aimed to determine the factors associated with an increased risk of developing RA. Preventive measures to reduce the frequency and intensity of anaphylactic events are essential to provide the best care for allergic patients. Aggravating factors can trigger or increase the severity of anaphylaxis and therefore need to be recognized and avoided. Methods: We retrospectively analyzed the data of 1378 patients over the age of 18 who were diagnosed with anaphylaxis in our clinic between January 1, 2020, and December 31, 2024. We divided the patients into two groups: anaphylaxis and RA. We evaluated the patients' clinical characteristics in the ED, demographic information, and elicitors that caused anaphylaxis. Results: Of the 1384 anaphylaxis patients included in the study, 46 (3.3%) were diagnosed as RA. We determined that having a history of anaphylaxis is the most important determinant of the increased risk of RA. Having a history of anaphylaxis (OR: 2.87, 95% CI: 1.71–5.72), beta‐blockers/ACEI use (OR: 2.47, 95% CI: 1.71–5.42), IV contrast agent (OR: 2.33, 95% CI: 1.64–5.39), and low blood pressure or related symptoms (OR: 2.34, 95% CI: 1.67–5.43) were more frequently associated with severe reactions. Conclusion: We found that having low blood pressure or related symptoms, a known history of anaphylaxis, beta‐blockers/ACEI, and IV contrast agent are risk factors for RA. To prevent mortality and morbidity in patients with this risk factor, early interventions such as rapidly repeating epinephrine doses and rapid fluid resuscitation should not be avoided. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC), characterized by a dense extracellular matrix (ECM), presents significant therapeutic challenges due to its poor prognosis and high resistance to chemotherapy. Current chemodrugs and diagnostic agents largely fail to cross the barrier posed by the ECM, which severely limits the PDAC theranostics. This study introduces a novel theranostic strategy using thioether-hybridized hollow mesoporous organosilica nanoparticles (dsMNs) for the co-delivery of copper (Cu) and disulfiram (DSF), aiming to induce cuproptosis in PDAC cells. Our approach leverages the ECM-degrading enzyme collagenase, integrated with dsMNs, to enhance drug penetration by reducing matrix stiffness. Furthermore, the innovative use of a pancreatic cancer cell membrane coating on the nanoparticles enhances tumor targeting and stability (dsMCu-D@M-Co). The multifunctional platform not only facilitates deep drug penetration and triggers cuproptosis effectively but also utilizes the inherent properties of Cu to serve as a T1-weighted magnetic resonance imaging (MRI) contrast agent. In vitro and in vivo assessments demonstrate significant tumor size reduction in PDAC-bearing mice, highlighting the dual functionality of our platform in improving therapeutic efficacy and diagnostic precision. This integrated strategy represents a significant advancement in the management of PDAC, offering a promising new direction for overcoming one of the most lethal cancers. [ABSTRACT FROM AUTHOR]

Serendipitously discovered, carbon dots (CDs) have attracted significant attention as a potential contrast agent for photoacoustic imaging (PAI) in the biomedical sector. CDs play an essential role in PAI, contributing significantly to the early detection of diseases and monitoring treatment progress, particularly in tumor imaging. This review emphasizes the role of CDs in the domain of PAI, highlighting their characteristics like biocompatibility, enhanced spatial resolution, optical absorption in the NIR region, and facile surface functionalization for tumor‐ targeted imaging. The study explores the use of CDs for enhancing spatial resolution in PAI for improved detection and visualization of tumors in organs such as the breast, cervical, liver, gastrointestinal, skin, cardiovascular system, nervous system, and others. Challenges associated with PAI, such as optimizing the signal‐to‐noise ratio and ensuring stability under physiological conditions, have also been discussed. [ABSTRACT FROM AUTHOR]

Ex vivo x‐ray angiography provides high‐resolution, three‐dimensional information on vascular phenotypes down to the level of capillaries. Sample preparation for ex vivo angiography starts with the removal of blood from the vascular system, followed by perfusion with an x‐ray dense contrast agent mixed with a carrier such as gelatine or a polymer. Subsequently, the vascular micro‐architecture of harvested organs is imaged in the intact fixed organ. In the present study, we present novel microscopic dual‐energy CT (microDECT) imaging protocols that allow to visualise and analyse microvasculature in situ with reference to the morphology of hard and soft tissue. We show that the spectral contrast of µAngiofil and Micropaque barium sulphate in perfused specimens allows for the effective separation of vasculature from mineralised skeletal tissues. Furthermore, we demonstrate the counterstaining of perfused specimens using established x‐ray dense contrast agents to depict blood vessels together with the morphology of soft tissue. Phosphotungstic acid (PTA) is used as a counterstain that shows excellent spectral contrast in both µAngiofil and Micropaque barium sulphate–perfused specimens. A novel Sorensen‐buffered PTA protocol is introduced as a counterstain for µAngiofil specimens, as the polyurethane polymer is susceptible to artefacts when using conventional staining solutions. Finally, we demonstrate that counterstained samples can be automatically processed into three separate image channels (skeletal tissue, vasculature and stained soft tissue), which offers multiple new options for data analysis. The presented microDECT workflows are suited as tools to screen and quantify microvasculature and can be implemented in various correlative imaging pipelines to target regions of interest for downstream light microscopic investigation. [ABSTRACT FROM AUTHOR]

Objective: The incidence of papillary thyroid caracinoma (PTC) is increasing year by year. Logistic regression model and Chi-squared automatic interaction (CHAID) decision tree based on multimodal ultrasound were established, and the diagnostic efficiency of the two models in PTC was compared. Methods: The findings, features and data of routine ultrasound, shear wave elastography (SWE) and contrast-enhanced ultrasonography (CEUS) were prospectively collected in 203 patients. Including: echogenicity, aspect ratio, maximum diameter of tumor, boundary, morphology, focal hyperecho, blood flow grading, maximum elasticity (Emax), minimum elastcity (Emin), mean elasticity (Emean), enhancement degree, enhanced characteristics, distribution of contrast agent, contrast medium arrival time. According to the pathological results, they were divided into PTC group and non-PTC group. CHAID decision tree model and binary Logistic regression model were established, receiver operator characteristic (ROC) curves of the two models were drawn, and diagnostic effectiveness was evaluated by comparing area under curve (AUC). Results: Logistic regression showed that hypoechoic or very hypoechoic, aspect ratio ≥1, microcalcification and high SWE value were risk factors for PTC (OR 8.604, 2.154, 2.297, 1.067, respectively, P < 0.05). The CHAID decision tree showed echo, aspect ratio, Emax, contrast agent distribution and infusion time combined to diagnose PTC. ROC curve showed that the AUC of PTC predicted by Logistic regression model and CHAID decision tree model was 0.878 and 0.883, respectively, with no statistical significance (z=0.325, P=0.7456). Conclusion: Both Logistic regression model and CHAID decision tree model can play a good role in the diagnosis of PTC based on multi-modal ultrasound, but the diagnostic efficiency of both models is comparable. In conclusion, these two models provide new insights and ideas for PTC diagnosis. [ABSTRACT FROM AUTHOR]

The Chemical Communications journal, published by The Royal Society of Chemistry, features articles on various topics such as catalytic enantioselective construction, microbial transformation of heavy metals, and alkyne annulations. The journal also covers topics like photoswitches, ammonia adsorption, and selective photocatalytic CO2 reduction. Additionally, the journal includes articles on topics like thiazole synthesis, redox platforms, and lanthanide coordination polymers. The publication aims to uncover new possibilities and provide fundamental answers to scientific questions. [Extracted from the article]

We herein report the construction of a robust MRI peptide contrast agent Gd-ICTP with superior selectivity for type I collagen, enabling the accurate and non-invasive detection of hepatic fibrosis in vivo. [ABSTRACT FROM AUTHOR]

Introduction: Magnetic particle imaging (MPI), a radiation-free, dynamic, and targeted imaging technique, has gained significant traction in both research and clinical settings worldwide. Signal-to-noise ratio (SNR) is a crucial factor influencing MPI image quality and detection sensitivity, and it is affected by ambient noise, system thermal noise, and the magnetization response of superparamagnetic nanoparticles. Therefore to address the high amplitude system and inherent thermal noise present in conventional MPI systems is essential to improve detection sensitivity and imaging resolution. Method: This study introduces a novel open-loop, narrow-band MPI signal acquisition system based on mixed-frequency harmonic magnetization response. Allowing superparamagnetic nanoparticles to be excited by low frequency, high amplitude magnetic fields and high frequency, low amplitude magnetic fields, the excitation coil generates a mixed excitation magnetic field at a mixed frequency of 8.664 kHz (f H + 2 f L ), and the tracer of superparamagnetic nanoparticles can generate a locatable superparamagnetic magnetization signal with rich harmonic components in the mixed excitation magnetic field and positioning magnetic field. The third harmonic signal is detected by a Gradiometer coil with high signal-to-noise ratio, and the voltage cloud image is formed. Result: The experimental results show that the external noise caused by the excitation coil can be effectively reduced from 12 to about 1.5 μV in the imaging area of 30 mm × 30 mm, which improves the stability of the detection signal of the Gradiometer coil, realizes the detection of high SNR, and makes the detection sensitivity reach 10 μg Fe. By mixing excitation, the total intensity of the excitation field is reduced, resulting in a slight improvement of the resolution under the same gradient field, and the spatial resolution of the image reconstruction is increased from 2 mm under the single frequency excitation (20.7 kHz) in the previous experiment to 1.5 mm under the mixed excitation (8.664 kHz). Conclusions: These experimental results highlight the effectiveness of the proposed open-loop narrowband MPI technique in improving signal detection sensitivity, achieving high signal-to-noise ratio detection and improving the quality of reconstructed images by changing the excitation magnetic field frequency of the excitation coil, providing novel design ideas and technical pathways for future MPI systems. [ABSTRACT FROM AUTHOR]

Background: Recent guidelines recommend direct patient observation, pressure monitoring, and sensor devices to prevent extravasation during contrast media (CM) injection. However, it is impractical in terms of time and cost to install sensors for all patients. Purpose: To identify risk factors for CM extravasations during contrast-enhanced computed tomography (CECT) in a large population and to establish criteria for placing the sensor device on patients. Material and Methods: This retrospective study included 143,556 patients who underwent CECT at our hospital between April 2012 and July 2022. We performed multivariable logistic regression analysis between patients with (n = 350) and randomly selected patients without CM extravasation (n = 350). We investigated the percentage of patients with sensor devices and their sensitivity for detecting extravasation using receiver operating characteristic curve analysis. Results: The extravasation rate was 0.27%. Multivariable logistic regression analysis showed that the injection rate (adjusted odds ratio [AOR] = 1.61, 95% confidence interval [CI] = 1.33–1.95: P <0.001), catheter gauge (AOR = 3.86, 95% CI = 1.92–7.76; P <0.001), the use of anticancer drugs (AOR = 1.81, 95% CI = 1.32–2.50; P <0.001), and existing catheters (AOR = 1.52, 95% CI = 1.10–2.11; P = 0.009) were significantly associated with extravasation. To achieve a sensitivity of 90%, 80%, 70%, 60%, and 50%, 80%, 65%, 50%, 40%, and 28% of all patients required the placement of a sensor device, respectively. Conclusion: Sensitivity analysis established criteria for effective placing sensor devices. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background and Aims: Outcome analysis of patients with Wilms' tumors (WT) is presented. Materials and Methods: A retrospective analysis of 23 children having WT managed by a single surgeon over 3 years (2021–2024) using the International Society of Paediatric Oncology Umbrella protocol was done. Results: The median age at presentation was 36 months; 32 months and 24 months for the unilateral WT (uWT) (n = 19) and bilateral WT (bWT) (n = 4), respectively. M: F ratio was 2.3: 1. WTs were localized in 19 (uWT-16; bWT-3) and metastatic in 4 (uWT-3; bWT-1) patients. Core-needle biopsy was done in 22 patients (26 renal units). Pre-therapy contrast-enhanced computed tomography volumetry (n = 20) showed a median tumor volume of 1023 ml (range: 47–2680 ml). Post-neoadjuvant chemotherapy (NACT) median tumor burden (n = 19) was 612 ml (range 59–3775 ml). Post-NACT, tumor volume decreased in 11/18 patients but increased in seven patients. NACT was avoided in one neonate. Nephroureterectomy (including one with excision of bladder cuff) and nephron-sparing surgery were done in 17 and 10 renal units including 3 with multifocal WT, respectively. Risk stratification was intermediate in 21 and High in 2. Overall staging in 19 uWT included Stage I-7, Stage II-5, Stage III-4, and Stage IV-3 (local staging-stage I in 1 and stage II in 2). Local staging in 8 renal units with bWT was Stage I in 7 and II in 1. One stage IV uWT had bilateral pulmonary metastatectomy. Adjuvant chemotherapy has been completed in 18 patients; two patients are still on adjuvant chemotherapy; flank radiation was administered in six patients. Three patients with synchronous bWT died; two due to acute kidney injury in the immediate postoperative period and one with metastatic disease who had abandoned adjuvant chemotherapy after the 1st cycle. Another patient died of a huge metachronous tumor in the contralateral kidney after a year of completion of therapy. One patient had successful multimodality treatment of local relapse with liver metastasis. 1-year overall and event-free survivals are 84% and 76%, respectively. Conclusions: Excellent short-term results for localized uWT from a center in a low-middle-income country are reported. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: Intranodal hemangiomas are rare benign vascular tumors of the lymph nodes, often misdiagnosed as malignant lymphadenopathies due to their clinical and radiological features. This case report and systematic review aim to elucidate the epidemiology, clinical profile, and therapeutic interventions for intranodal hemangioma, enhancing diagnostic accuracy and management. Methods: A systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Searches were conducted in PubMed, Scopus, Web of Science, and Google Scholar up to March 15, 2024, using keywords like "intranodal hemangioma," "primary intranodal hemangioma," "nodal hemangioma," "vascular tumor," and "lymph node hemangioma." Inclusion criteria included studies on clinical presentation, diagnostic strategies, and therapeutic interventions for intranodal hemangioma in patients of all ages. Excluded were reviews, opinion pieces, non-English studies, cases of hemangioendothelioma, sclerosing hemangioma, and animal studies. Key aspects analyzed included demographics, clinical presentation, management strategies, and histopathological findings. Results: Our case involves a 3-year-old female with a submandibular mass, initially diagnosed with hemangioma. After no response to beta-blocker therapy and conflicting imaging results, surgical excision was performed. Histopathology confirmed intranodal hemangioma. From 233 records, 19 publications (36 patients, including our case) met the inclusion criteria. The review shows common clinical presentations as painless, slowly enlarging lymph nodes, primarily in the cervical and axillary regions. Diagnostic challenges often require imaging and biopsy to differentiate from malignancies. Conclusion: Recognizing intranodal hemangiomas, particularly in childhood, is crucial to prevent misdiagnosis and inappropriate treatment. The rarity of these tumors in childhood and their clinical presentation similar to malignancies in older patients make diagnosis challenging without widespread awareness. Surgical excision remains the mainstay of both diagnosis and treatment, often leading to favorable outcomes. [ABSTRACT FROM AUTHOR]

Fe3O4 magnetic nanoparticles exhibit significant potential for cancer detection due to their unique magnetic properties and versatility. This review examines their role in enhancing cancer biomarker detection, focusing on synthesis methods, surface modifications and diagnostic accuracy. Fe3O4 nanoparticles serve as sensitive MRI contrast agents, facilitating early cancer diagnosis and improving patient prognosis. Synthesis techniques influence their properties, morphology and dimensions, which affect performance. Surface modifications enhance targeting and reduce immunological reactions, enabling precise biomarker detection and effective drug delivery to tumours, minimizing damage to healthy tissue. Despite these advantages, challenges remain in optimizing delivery efficiency and overcoming medication resistance. Further research is required to understand the pharmacokinetics and pharmacodynamics of these nanoparticles, including their distribution, metabolism and physiological impacts. This review provides insights into the potential of Fe3O4 magnetic nanoparticles as cancer detection agents, aiming to guide future research towards developing safer and more efficient applications in medical diagnostics and treatment. [ABSTRACT FROM AUTHOR]

Background and Purpose: To develop and test a decision tree for predicting contrast enhancement quality and shape using precontrast magnetic resonance imaging (MRI) sequences in a large adult‐type diffuse glioma cohort. Methods: Preoperative MRI scans (development/optimization/test sets: n = 31/38/303, male = 17/22/189, mean age = 52/59/56.7 years, high‐grade glioma = 22/33/249) were retrospectively evaluated, including pre‐ and postcontrast T1‐weighted, T2‐weighted, fluid‐attenuated inversion recovery, and diffusion‐weighted imaging sequences. Enhancement prediction decision tree (EPDT) was developed using development and optimization sets, incorporating four imaging features: necrosis, diffusion restriction, T2 inhomogeneity, and nonenhancing tumor margins. EPDT accuracy was assessed on a test set by three raters of variable experience. True enhancement features (gold standard) were evaluated using pre‐ and postcontrast T1‐weighted images. Statistical analysis used confusion matrices, Cohen's/Fleiss' kappa, and Kendall's W. Significance threshold was p <.05. Results: Raters 1, 2, and 3 achieved overall accuracies of.86 (95% confidence interval [CI]:.81‐.90),.89 (95% CI:.85‐.92), and.92 (95% CI:.89‐.95), respectively, in predicting enhancement quality (marked, mild, or no enhancement). Regarding shape, defined as the thickness of enhancing margin (solid, rim, or no enhancement), accuracies were.84 (95% CI:.79‐.88),.88 (95% CI:.84‐.92), and.89 (95% CI:.85‐.92). Intrarater intergroup agreement comparing predicted and true enhancement features consistently reached substantial levels (≥.68 [95% CI:.61‐.75]). Interrater comparison showed at least moderate agreement (group: ≥.42 [95% CI:.36‐.48], pairwise: ≥.61 [95% CI:.50‐.72]). Among the imaging features in the EPDT, necrosis assessment displayed the highest intra‐ and interrater consistency (≥.80 [95% CI:.73‐.88]). Conclusion: The proposed EPDT has high accuracy in predicting enhancement patterns of gliomas irrespective of rater experience. [ABSTRACT FROM AUTHOR]

Background: Recent advancements in cervical interlaminar epidural steroid injections have given rise to the modified paramedian interlaminar (mPIL) approach. The objective of this study was to perform an analysis of the contrast spread pattern within the cervical epidural space, taking into account different needle tip positions in the mPIL approach. Methods: A total of 48 patients were included in the study and randomly assigned to either the medial or lateral group based on the needle tip's position in the anterior–posterior view. The primary outcome measured was the contrast flow under fluoroscopic visualization. As a secondary outcome, we analyzed the location of the needle tip position in both lateral and contralateral oblique views. Clinical effectiveness was assessed by measuring pain intensity and functional disability post‐procedure. Results: Significant disparities were noted in the ventral distribution of contrast between the medial and lateral groups. In the lateral images, needle tips in the lateral group were positioned more ventrally compared to those in the medial group. Both groups exhibited statistically significant improvements in neck and radicular pain, as well as functional status, 4 weeks after treatment, with no significant differences between them. Conclusions: Our results suggest that the ventral dispersion of contrast material during cervical interlaminar epidural steroid injections using the mPIL approach may vary depending on the needle tip location. [ABSTRACT FROM AUTHOR]

Background: Herniated intervertebral disc (HIVD) with radiculopathy is a common degenerative spine disorder. Transforaminal epidural steroid injection (TFESI) is one of the pain relief treatments for lumbar radiculopathy recommended by evidence‐based guidelines. Adequate contrast distribution is correlated with better pain control, but the best approach has not been confirmed yet. Aim: To confirm the distribution of contrast medium injected with a new approach of TFESI, that is, far lateral lateral recess approach (FLLR‐TFESI). Methods: Patients receiving TFESI due to HIVD with radiculopathy between 2010 January and 2020 August were retrospectively enrolled. While the FLLR‐TFESI was taken as the experimental group, the conventional approach was viewed as the control group. The baseline characteristics, the pattern of contrast enhancement under fluoroscopic guidance, and the complications of these patients were collected and analyzed. Results: A total of 380 patients were analyzed (143 in control group and 237 in experimental group). The two groups were balanced in most baseline characteristics, except disc extrusion (p = 0.01) and scoliosis (p = 0.04). The FLLR‐TFESI have a better contrast distribution (p < 0.01), even after adjustment (p < 0.001). No intrathecal injection was noted, but higher rate of intra‐disc injection was noted in FLLR‐TFESI group (10% vs. 3%, p = 0.008). Conclusion: The FLLR‐TFESI has a superior contrast enhancement and distribution in comparison to conventional approach. Prospective study to confirm the study result as well as the clinical benefits is suggested in the future. [ABSTRACT FROM AUTHOR]

Background: Our study aims to provide an overview of existing evidence regarding the image quality of dual-energy CT (DECT) employing reduced contrast media (CM) volumes, in comparison to single-energy CT (SECT) with standard CM loads. The advantages, indications, and possible applications of DECT were investigated from the perspective of providing better patient care, minimizing CM volume and managing CM shortage. Methods: In this systematic review (PRISMA methodology), PubMed and WOS were searched from January 2010 to January 2023 by two independent reviewers. The scan and CM characteristics, radiation dose, and results of quantitative (contrast to noise ratio, CNR, and signal to noise ratio, SNR) and qualitative assessment of image quality were collected. Sixty non-duplicated records eligible for full-text screening were examined. Results: Finally, 22 articles (1818 patients) were included. The average CM reduction with DECT ranged between 43.4 ± 11%. Despite the wide variability in CT scan protocols, no differences were found in radiation doses between DECT and SECT. Conclusions: DECT scanners allow the employment of lower CM volumes with equal or better image quality evaluated by quantitative and qualitative analyses and similar dose radiation compared to SECT. Using image reconstructions at low monochromatic energy levels, DECT increases iodine conspicuity and attenuation contributing to CM containment measures. [ABSTRACT FROM AUTHOR]

PURPOSE: Contrast Enhancement Magnetic Resonance (CEMR) and Contrast-Enhanced Mammography (CEM) are important diagnostic tools to evaluate breast cancer patients, and both are objects of interest in the literature. The purpose of this systematic review was to select publications from the last ten years in order to evaluate the literature contributions related to the frequency of contrast agents used, administration techniques and the presence of adverse reactions. METHODS: We have selected, according to the PRISMA statement, publications reviewed on Pub Med in the period from 1 January 2012 to 31 December 2022. The search engine was activated using the following keywords: "CESM", "CEM", "CEDM", "Contrast mammography" for CEM, "DCE-MRI", "Contrast Enhancement MRI" for CEMR, excluding reviews, book chapters and meta-analyses. From the total number of publications, we made a preliminary selection based on titles and abstracts and excluded all articles published in languages other than English and all experimental studies performed on surgical specimen or animal population, as well as all articles for which the extended version was not available. Two readers evaluated all the articles and compiled a pre-compiled form accordingly. RESULTS: After a preliminary collection of 571 CEM publications, 118 articles were selected, relating to an overall population of 21,178 patients. From a total of 3063 CEMR publications, 356 articles relating to an overall population of 45,649 patients were selected. The most used contrast agents are Iohexol for CEM (39.83%) and Gadopentetic acid (Gd-DTPA) for CEMR (32.5%). Regarding the CEM contrast administration protocol, in 84.7% of cases a dose of 1.5 mL/kg was used with an infusion rate of 2–3 mL/s. Regarding the CEMR infusion protocol, in 71% of cases a dose of 1 mmol/kg was used at an infusion rate of 2–4 mL/s. Twelve out of 118 CEM articles reported allergic reactions, involving 29 patients (0.13%). In DCE-MRI, only one out of 356 articles reported allergic reactions, involving two patients (0.004%). No severe reactions were observed in either cohort of exams. CONCLUSIONS: CEM and CEMR are essential contrast methods to evaluate breast diseases. However, from the literature analysis, although there are preferences on the uses of the contrast agent (Iohexol for CESM, G-DTPA for CEMR), a wide range of molecules are still used in contrast methods, with different administration protocols. Based on the collected data, it is possible to state that both methods are safe, and no severe reactions were observed in our evaluation. [ABSTRACT FROM AUTHOR]

Ganglioneuroblastoma is a rare peripheral neuroblastic tumor located anywhere in the sympathetic nervous system but rarely in the retropharyngeal space. Diagnosis can often be difficult based on imaging alone. We describe one case of a child presenting with snoring. The lesion was located in the rare retropharyngeal space, and its histology finally revealed ganglioneuroblastoma. Therefore, clinicians should be aware of pediatric patients with respiratory symptoms indicating cervical ganglioneuroblastoma. To make a definite diagnosis as soon as possible, a core needle biopsy or even immunohistochemistry may need to be performed before surgery. [ABSTRACT FROM AUTHOR]

Background: Nasal irrigation is among the most widely used treatment modalities for sinonasal diseases. The extent of irrigation is well studied in operated sinuses but not for non-operated sinuses. Moreover, the preferred head positioning during irrigation is not known. Herein, we studied the extent of nasal irrigation in cadaveric heads with non-operated sinuses. Methods: Nine cadaveric heads were used. Normal saline solution mixed with radiological contrast material was used to irrigate the nasal cavities with the heads in 2 different positions: standing-leaning-forward (SLF) and Head-down forward (HDF). After each irrigation, computed tomography images of the head were acquired. The extent of irrigation was assessed for each subunit of the sinonasal cavity. Results: Irrigation was performed twice on a total of 18 sides, each time in 1 position. Nine subunits were evaluated: inferior, middle, and superior meati; the olfactory cleft; and the frontal, maxillary, anterior, and posterior ethmoid and sphenoid sinuses. The extent of irrigation was significantly better in the HDF position for the olfactory cleft (100% vs 33%), P -value=.001, frontal sinus (33% vs 11%), P -value=.002, maxillary sinus (78% vs 17%), P -value=.001, and anterior ethmoid sinus (89% vs 17%), P -value=.001. There was no significant difference in the extent of irrigation between the 2 positions for the other evaluated subunits. The overall extent of irrigation was 70.37% of the subunits in HDF position and 45.06% of the subunits for SLF position, P -value=.001 Conclusions: Nasal irrigation reached the cavities of non-operated paranasal sinuses. However, while the extent of irrigation was limited in the SLF, it was well achieved in the HDF position. Studies on the clinical efficacy of irrigation in this position are recommended. [ABSTRACT FROM AUTHOR]

Purpose: Head and neck emergencies in children are frequent cause of visits to the hospital. Imaging plays a critical role in the management of these patients. This review article aims to familiarize radiologists with the common clinical presentations encountered, imaging characteristics of nontraumatic pediatric head and neck emergencies, and improve their ability to recognize associated complications as well as be aware of common mimics. Methods: We researched our database for commonly encountered nontraumatic head and neck emergencies in children. A literature search was done to compare and complete the list of conditions to be discussed in this review. Results: The review was organized according to anatomical location of the emergent condition. Relevant anatomy has been discussed along with clinical presentation, imaging characteristics and complications. We have presented common mimics with each set of disorders. Key imaging characteristics have been delineated using radiology images. Conclusion: Familiarity with the known complications of head and neck emergencies allows the radiologist to actively search for such findings, encourage early institution of appropriate therapy, and improve outcomes. [ABSTRACT FROM AUTHOR]

Purpose: For patients with vestibular schwannomas (VS), a conservative observational approach is increasingly used. Therefore, the need for accurate and reliable volumetric tumor monitoring is important. Currently, a volumetric cutoff of 20% increase in tumor volume is widely used to define tumor growth in VS. The study investigates the tumor volume dependency on the limits of agreement (LoA) for volumetric measurements of VS by means of an inter-observer study. Methods: This retrospective study included 100 VS patients who underwent contrast-enhanced T1-weighted MRI. Five observers volumetrically annotated the images. Observer agreement and reliability was measured using the LoA, estimated using the limits of agreement with the mean (LOAM) method, and the intraclass correlation coefficient (ICC). Results: The 100 patients had a median average tumor volume of 903 mm3 (IQR: 193–3101). Patients were divided into four volumetric size categories based on tumor volume quartile. The smallest tumor volume quartile showed a LOAM relative to the mean of 26.8% (95% CI: 23.7–33.6), whereas for the largest tumor volume quartile this figure was found to be 7.3% (95% CI: 6.5–9.7) and when excluding peritumoral cysts: 4.8% (95% CI: 4.2–6.2). Conclusion: Agreement limits within volumetric annotation of VS are affected by tumor volume, since the LoA improves with increasing tumor volume. As a result, for tumors larger than 200 mm3, growth can reliably be detected at an earlier stage, compared to the currently widely used cutoff of 20%. However, for very small tumors, growth should be assessed with higher agreement limits than previously thought. [ABSTRACT FROM AUTHOR]

Osteoporosis is underdiagnosed and undertreated. To improve timely fracture risk assessment optimized densitometry methods are required such as opportunistic spinal quantitative computed tomography (QCT). However, it is unclear how to best calibrate these scans and correct for potential scanner drift of QCT when used for monitoring bone mineral density (BMD) changes. We compared gold standard simultaneous calibration with asynchronous calibration methods, assessing mid-term (12 weeks) and long-term (1.5 years) reproducibility of BMD measurements. Cortical and trabecular compartments of the European Spine Phantom were studied with ten different protocols including low dose and high resolution (HR)-modes. Based on weekly phantom data, we compared simultaneous calibration to asynchronous single (termed global) or monthly calibration. The accuracy was better for trabecular measurements than for cortical measurements for all calibration methods. Reproducibility was excellent for all methods and slightly better for asynchronous than for simultaneous calibration both for trabecular and cortical bone. For HR protocols, reproducibility was better than for low dose measurements. In trabecular compartments averaged HR-BMD remained stable for global (− 0.1%/year, ns) but not for simultaneous calibration (− 1.5%/year, p < 0.001). No significant drifts could be detected for averaged low dose BMD (− 0.9 to + 0.8%/year) for either calibration method. Our data suggest that with regard to precision and accuracy measurements with asynchronous calibration are suitable for vertebral BMD assessment (no contrast agents) in clinical practice. Regular (e.g., monthly) stability tests using a calibration phantom could assure long term stability of at least 1 year. [ABSTRACT FROM AUTHOR]

Background: Quantification of pulmonary edema in patients with acute respiratory distress syndrome (ARDS) by chest computed tomography (CT) scan has not been validated in routine diagnostics due to its complexity and time-consuming nature. Therefore, the single-indicator transpulmonary thermodilution (TPTD) technique to measure extravascular lung water (EVLW) has been used in the clinical setting. Advances in artificial intelligence (AI) have now enabled CT images of inhomogeneous lungs to be segmented automatically by an intensive care physician with no prior radiology training within a relatively short time. Nevertheless, there is a paucity of data validating the quantification of pulmonary edema using automated lung segmentation on CT compared with TPTD. Methods: A retrospective study (January 2016 to December 2021) analyzed patients with ARDS, admitted to the intensive care unit of the Department of Anesthesiology and Critical Care Medicine, University Hospital Mannheim, who underwent a chest CT scan and hemodynamic monitoring using TPTD at the same time. Pulmonary edema was estimated using manually and automated lung segmentation on CT and then compared to the pulmonary edema calculated from EVLW determined using TPTD. Results: 145 comparative measurements of pulmonary edema with TPTD and CT were included in the study. Estimating pulmonary edema using either automated lung segmentation on CT or TPTD showed a low bias overall (− 104 ml) but wide levels of agreement (upper: 936 ml, lower: − 1144 ml). In 13% of the analyzed CT scans, the agreement between the segmentation of the AI algorithm and a dedicated investigator was poor. Manual segmentation and automated segmentation adjusted for contrast agent did not improve the agreement levels. Conclusions: Automated lung segmentation on CT can be considered an unbiased but imprecise measurement of pulmonary edema in mechanically ventilated patients with ARDS. [ABSTRACT FROM AUTHOR]

Contrast-enhanced ultrasound (CEUS) is an advanced ultrasound (US) technique utilizing ultrasound contrast agents (UCAs) to provide detailed visualization of anatomic and vascular architecture, including the depiction of microcirculation. CEUS has been well-established in echocardiography and imaging of focal hepatic lesions and recent studies have also shown the utility of CEUS in non-hepatic applications like the urinary system. The updated guidelines by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) from 2018 describe the use of CEUS for non-hepatic applications. CEUS' excellent safety profile and spatial resolution make it a superior modality to conventional US and is often comparable and even superior to CECT in some instances. In comparison to other cross-sectional imaging modalities such as CECT or MRI, CEUS offers a safe (by virtue of non-nephrotoxic US contrast agents), accurate, cost-efficient, readily available, and a quick means of evaluation of multiple pathologies of the urinary system. CEUS also has the potential to reduce the overall economic burden on patients requiring long-term follow-up due to its low cost as compared to CT or MRI techniques. This comprehensive review focuses on the applications of CEUS in evaluating the urinary system from the kidneys to the urinary bladder. CEUS can be utilized in the kidney to evaluate complex cystic lesions, indeterminate lesions, pseudotumors (vs solid renal tumors), renal infections, and renal ischemic disorders. Additionally, CEUS has also been utilized in evaluating renal transplants. In the urinary bladder, CEUS is extremely useful in differentiating a bladder hematoma and bladder cancer when conventional US techniques show equivocal results. Quantitative parameters of time-intensity curves (TICs) of CEUS examinations have also been studied to stage and grade bladder cancers. Although promising, further research is needed to definitively stage bladder cancers and classify them as muscle-invasive or non-muscle invasive using quantitative CEUS to guide appropriate intervention. CEUS has been very effective in the classification of cystic renal lesions, however, further research is needed in differentiating benign from malignant renal masses. [ABSTRACT FROM AUTHOR]

Purpose: This review aims to provide a comprehensive summary of DECT techniques, acquisition workflows, and post-processing methods. By doing so, we aim to elucidate the advantages and disadvantages of DECT compared to conventional single-energy CT imaging. Methods: A systematic search was conducted on MEDLINE/EMBASE for DECT studies in liver imaging published between 1980 and 2024. Information regarding study design and endpoints, patient characteristics, DECT technical parameters, radiation dose, iodinated contrast agent (ICA) administration and postprocessing methods were extracted. Technical parameters, including DECT phase, field of view, pitch, collimation, rotation time, arterial phase timing (from injection), and venous timing (from injection) from the included studies were reported, along with formal narrative synthesis of main DECT applications for liver imaging. Results: Out of the initially identified 234 articles, 153 met the inclusion criteria. Extensive variability in acquisition parameters was observed, except for tube voltage (80/140 kVp combination reported in 50% of articles) and ICA administration (1.5 mL/kg at 3–4 mL/s, reported in 91% of articles). Radiation dose information was provided in only 40% of articles (range: 6–80 mGy), and virtual non-contrast imaging (VNC) emerged as a common strategy to reduce the radiation dose. The primary application of DECT post-processed images was in detecting focal liver lesions (47% of articles), with predominance of study focusing on hepatocellular carcinoma (HCC) (27%). Furthermore, a significant proportion of the articles (16%) focused on enhancing DECT protocols, while 15% explored metastasis detection. Conclusion: Our review recommends using 80/140 kVp tube voltage with 1.5 mL/kg ICA at 3–4 mL/s flow rate. Post-processing should include low keV-VMI for enhanced lesion detection, IMs for tumor iodine content evaluation, and VNC for dose reduction. However, heterogeneous literature hinders protocol standardization. [ABSTRACT FROM AUTHOR]

Objective: Computed tomography (CT)/magnetic resonance imaging (MRI) Liver Imaging Reporting and Data System (LI-RADS, LR) category 5 has high specificity and modest sensitivity for diagnosis of hepatocellular carcinoma (HCC). The purpose of this study was to compare the diagnostic performance of LR-5 vs combined LR-4 and LR-5 (LR-4/5) for HCC diagnosis. Methods: MEDLINE and EMBASE databases through January 03, 2023 were searched for studies reporting the performance of LR-5 and combined LR-4/5 for HCC diagnosis, using CT/MRI LI-RADS version 2014, 2017, or 2018. A bivariate random-effects model was used to calculate the pooled per-observation diagnostic performance. Subgroup analysis was performed based on imaging modalities and type of MRI contrast material. Results: Sixty-nine studies (15,108 observations, 9928 (65.7%) HCCs) were included. Compared to LR-5, combined LR-4/5 showed significantly higher pooled sensitivity (83.0% (95% CI [80.3–85.8%]) vs 65.7% (95% CI [62.4–69.1%]); p < 0.001), lower pooled specificity (75.0% (95% CI [70.5–79.6%]) vs 91.7% (95% CI [90.2–93.1%]); p < 0.001), lower pooled positive likelihood ratio (3.60 (95% CI [3.06–4.23]) vs 6.18 (95% CI [5.35–7.14]); p < 0.001), and lower pooled negative likelihood ratio (0.22 (95% CI [0.19–0.25]) vs 0.38 (95% CI [0.35–0.41]) vs; p < 0.001). Similar results were seen in all subgroups. Conclusions: Our meta-analysis showed that combining LR-4 and LR-5 would increase sensitivity but decrease specificity, positive likelihood ratio, and negative likelihood ratio. These findings may inform management guidelines and individualized management. Clinical relevance statement: This meta-analysis estimated the magnitude of changes in the sensitivity and specificity of imaging criteria when LI-RADS categories 4 and 5 were combined; these findings can inform management guidelines and individualized management. Key Points: There is no single worldwide reporting system for liver imaging, partly due to regional needs. Combining LI-RADS categories 4 and 5 increased sensitivity and decreased specificity and positive and negative likelihood ratios. Changes in the sensitivity and specificity of imaging criteria can inform management guidelines and individualized management. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the feasibility of low-radiation dose and low iodinated contrast medium (ICM) dose protocol combining low-tube voltage and deep-learning reconstruction (DLR) algorithm in thin-slice abdominal CT. Methods: This prospective study included 148 patients who underwent contrast-enhanced abdominal CT with either 120-kVp (600 mgL/kg, n = 74) or 80-kVp protocol (360 mgL/kg, n = 74). The 120-kVp images were reconstructed using hybrid iterative reconstruction (HIR) (120-kVp-HIR), while 80-kVp images were reconstructed using HIR (80-kVp-HIR) and DLR (80-kVp-DLR) with 0.5 mm thickness. Size-specific dose estimate (SSDE) and iodine dose were compared between protocols. Image noise, CT attenuation, and contrast-to-noise ratio (CNR) were quantified. Noise power spectrum (NPS) and edge rise slope (ERS) were used to evaluate noise texture and edge sharpness, respectively. The subjective image quality was rated on a 4-point scale. Results: SSDE and iodine doses of 80-kVp were 40.4% (8.1 ± 0.9 vs. 13.6 ± 2.7 mGy) and 36.3% (21.2 ± 3.9 vs. 33.3 ± 4.3 gL) lower, respectively, than those of 120-kVp (both, p < 0.001). CT attenuation of vessels and solid organs was higher in 80-kVp than in 120-kVp images (all, p < 0.001). Image noise of 80-kVp-HIR and 80-kVp-DLR was higher and lower, respectively than that of 120-kVp-HIR (both p < 0.001). The highest CNR and subjective scores were attained in 80-kVp-DLR (all, p < 0.001). There were no significant differences in average NPS frequency and ERS between 120-kVp-HIR and 80-kVp-DLR (p ≥ 0.38). Conclusion: Compared with the 120-kVp-HIR protocol, the combined use of 80-kVp and DLR techniques yielded superior subjective and objective image quality with reduced radiation and ICM doses at thin-section abdominal CT. Clinical relevance statement: Scanning at low-tube voltage (80-kVp) combined with the deep-learning reconstruction algorithm may enhance diagnostic efficiency and patient safety by improving image quality and reducing radiation and contrast doses of thin-slice abdominal CT. Key Points: Reducing radiation and iodine doses is desirable; however, contrast and noise degradation can be detrimental. The 80-kVp scan with the deep-learning reconstruction technique provided better images with lower radiation and contrast doses. This technique may be efficient for improving diagnostic confidence and patient safety in thin-slice abdominal CT. [ABSTRACT FROM AUTHOR]

Multiparametric MRI is the optimal primary investigation when prostate cancer is suspected, and its ability to rule in and rule out clinically significant disease relies on high-quality anatomical and functional images. Avenues for achieving consistent high-quality acquisitions include meticulous patient preparation, scanner setup, optimised pulse sequences, personnel training, and artificial intelligence systems. The impact of these interventions on the final images needs to be quantified. The prostate imaging quality (PI-QUAL) scoring system was the first standardised quantification method that demonstrated the potential for clinical benefit by relating image quality to cancer detection ability by MRI. We present the updated version of PI-QUAL (PI-QUAL v2) which applies to prostate MRI performed with or without intravenous contrast medium using a simplified 3-point scale focused on critical technical and qualitative image parameters. Clinical relevance statement: High image quality is crucial for prostate MRI, and the updated version of the PI-QUAL score (PI-QUAL v2) aims to address the limitations of version 1. It is now applicable to both multiparametric MRI and MRI without intravenous contrast medium. Key Points: High-quality images are essential for prostate cancer diagnosis and management using MRI. PI-QUAL v2 simplifies image assessment and expands its applicability to prostate MRI without contrast medium. PI-QUAL v2 focuses on critical technical and qualitative image parameters and emphasises T2-WI and DWI. [ABSTRACT FROM AUTHOR]

Hepatocellular adenomas (HCA) are acquired focal liver lesions, that occur mainly in young-to-middle-aged women who are on long-term estrogen-containing contraceptives or young men after prolonged use of anabolic steroids. Furthermore, distinct underlying diseases, such as obesity, metabolic dysfunction-associated steatotic liver disease, glycogen storage disease, etc. are considered risk factors. The 2017 Bordeaux classification, in particular Nault et al, divided HCAs into eight subtypes according to their pheno- and genotypic characteristics. This includes HCAs with hepatocyte-nuclear-factor (HNF1-alpha mutation), HCAs with β-catenin mutation, and HCAs without either of these genetic mutations, which are further subdivided into HCAs with and without inflammatory cells. HCAs should no longer be classified as purely benign without histologic workup since three of the eight subtypes are considered high-risk lesions, requiring adequate management: malignant transformation of the pure (ßex3-HCA) and mixed inflammatory/β-catenin exon 3 (ßex3-IHCA) adenomas, as well as potential bleeding of the sonic hedgehog HCA and pure (ßex7/8-HCA) and mixed inflammatory/β-catenin exon 7/8 (ßex7/8-IHCA). Elective surgery is recommended for any HCA in a male, or for any HCA exceeding 5 cm. Although MRI can classify up to 80% of adenomas, if findings are equivocal, biopsy remains the reference standard for adenoma subtype. [ABSTRACT FROM AUTHOR]

In situ forming implants (ISFIs) composed of biodegradable polymers and biocompatible solvents are generally designed for sustained drug release. In this study, a non-invasive computed tomography (CT) imaging approach is used to achieve real time imaging of ISFIs in vivo and in vitro using leuprolide acetate in situ forming implant as a model drug product. The process of implant formation, inner structure change and their impact on drug release were elucidated. Real-time drug distribution was unveiled by the CT contrast agent, iohexol, where it shows a core-shell structure of the deposition. The incorporation of leuprolide acetate (LA) led to a reduced extent of burst release, prolongated release profile, and extended implant size expansion. LA was found to interact with the solvent and slowed down the polymer phase inversion, thus significantly changed the drug distribution in the implant and reduced the drug release. The implant inner structure identified through SEM, implant size change, and polymer degradation along with the CT real time imaging all consistently support the implant formation differences and their implant on the drug release. Similar patterns of implant size expansion and iohexol distribution in the implants were observed both in vitro and in vivo for the implants with and without LA. The comprehensive understanding of the impact of implant formation on drug release through real time CT imaging facilitates the ISFI product development and evaluation. [Display omitted] [ABSTRACT FROM AUTHOR]

To prospectively determine whether extrinsic warming of the low-osmolality CT contrast media (Iohexol 350, Iodixanol 320, Iopromide 300, and Iopamidol 300) to 37°C prior to intravenous administration affects extravasation and allergic-like reaction rates. This large scale prospective case control study of adverse events included all the patients between the age group of 15–80 years undergoing routine contrast–enhanced computed tomographic (CECT) examinations from April 2018 to March 2020 at our institute. Ex vivo experiments were also performed to demonstrate change in contrast viscosity and fluid dynamics in relation to temperature. A total of 24,379 CECTs were conducted during the study period. Extrinsic warming showed a significant decrease in extravasation rates for Iohexol 350 at flow rates <3.5 mL/sec (P=0.037). No significant difference was observed with Iopromide 300 (P=0.432). Overall, a significant decrease in allergic reactions and overall contrast-related reactions (excluding physiologic reactions) was noted (P<0.001), with Iohexol 350. However, no significant difference was found with Iopromide 300. The most common physiological reaction was a sense of warmth, more prevalent in the warmed group, aligning with ex-vivo experiments demonstrating decreased viscosity with contrast warming. Extrinsic warming of contrast helps reduce the incidence of allergic-like reactions and extravasations for Iohexol 350, but no significant difference was noted with Iopromide 300 even at low injection rates (<3.5 mL/sec). • Warming contrast media to 37°C significantly reduces adverse reactions. • Iohexol 350 showed fewer extravasations and allergic reactions when warmed. • No significant difference in reactions for warmed vs. non-warmed Iopromide 300. • Physiologic reactions like nausea are higher with non-warmed contrast media. • Study supports extrinsic warming of CT contrast for reducing adverse effects. [ABSTRACT FROM AUTHOR]

To assess the efficiency and diagnostic value of the "real" one-stop-shop protocol integrating the computed tomography angiography (CTA) sequence of the head and neck into the computed tomography perfusion (CTP) acquisition using a 512-slice detector CT scanner in patients who suffered from acute ischemic stroke. This prospective study included 100 patients suspected of acute ischemic stroke. The patients were randomly divided into two groups: the control group (n=50) who underwent the traditional protocol (brain CTP and head-and-neck CTA examination separately) and the experimental group (n=50) who underwent a one-stop-shop protocol (combined brain CT perfusion and head-and-neck CTA, the CTA triggering time determined by a low-dose test bolus injection). The examination time, contrast-agent dosage, radiation dose, postprocessing time, and image quality were compared between the two groups. Compared to the control group, the experimental group had a significantly lower total iodine contrast-agent dosage (80 vs. 100 ml, P <0.001) and shorter scan time (3.23 [3.13, 3.35] vs. 2.32 [2.17, 2.45] min, P <0.001). Additionally, the radiation dose exposure was lower in the experimental group than in the control group (5129.00 [5173, 5232] vs. 4681.35 [4555.12, 4822.95] mGy-cm, P <0.001). No statistically significant differences were observed between the two groups in terms of postprocessing time, head-and-neck CTA, and CTP imaging quality. The one-stop-shop protocol enables effective detection of lesions, providing clear visualization of the location and degree of stenosis in the head-and-neck vessels. It achieves this with lower costs in scan time, contrast-agent dosage, and radiation dose compared to the traditional protocol and is thus worth considering as the first examination for patients who suffer from acute ischemic stroke. • The one-stop-shop solution integrates CTA sequence into CTP acquisition protocol. • The one-stop-shop protocol eliminates the need for two injections of contrast agents. • The shorter scanning time, radiation exposure, and lower contrast-agent dosages. • The one-stop-shop protocol provides high-quality images. [ABSTRACT FROM AUTHOR]

To prospectively assess the value of a test bolus of diluted contrast medium (CM) combined with a personalized contrast protocol in craniocervical computed tomography angiography (cc-CTA) with low radiation and CM doses. Eighty-six consecutive subjects were divided into two groups at random (43 in each one): group A: 100/Sn140 kVp, filtered back-projection reconstruction, iopromide (370 mgI/ml) 50 ml; group B: 80/Sn140 kVp, iterative reconstruction, iodixanol (270 mgI/ml). In group B, the test bolus contained 27 ml of diluted CM, a personalized protocol with low-concentration CM was used for angiography, and the test bolus injection duration in angiography remained the same. Artery values over 200 Hounsfield units were considered significant. Image quality for all cases was found to be diagnostic. No significant differences were found in the arterial densities of the ascending aorta or basilar artery between the groups. The values of the common carotid artery, internal carotid artery, and middle cerebral artery in group B were significantly lower. The effective dose and average iodine uptake were significantly lower in group B. With double-low-dose cc-CTA, test bolus scanning based on diluted CM combined with a personalized contrast protocol can yield diagnostic-quality images and significantly reduce the radiation and CM doses. • Test bolus with diluted contrast medium (CM) allows for precise anticipation of the scan trigger time. • A personalized CM protocol made it feasible to further reduce iodine uptake. • The double low dose protocol can get images with diagnostic quality in craniocervical computed tomography angiography. [ABSTRACT FROM AUTHOR]