Iodinated Contrast Agent Research Articles

Virtual diluted cone beam CT for device apposition assessment during endovascular treatment of intracranial aneurysm: A technical note

The increasing use of embolization devices with suboptimal radio-opacity to treat intracranial aneurysm underscores the need for advanced imaging techniques to characterize device-vessel interactions more accurately. Contrast-diluted cone-beam CT is commonly used in neurointervention but requires additional technical refinements to improve endovascular treatment assessment. In this technical note, we describe the virtual dilution cone beam CT (VDCBCT), a technique that synthetizes non-contrast and contrast-enhanced CBCT images to virtually dilute iodinated contrast agents, thereby facilitating a more accurate assessment of embolization device apposition.Through a set of intracranial aneurysms treated with different embolization devices, we describe the VDCBCT protocol and its usefulness for device apposition confidence.VDCBCT may enhance the global understanding of neurovascular embolization treatments by providing improved visualization of target vessels and low-radio-opacity embolization devices, obviating the need for contrast dilution.

P-29 Metformin poisoning without lactic acidosis: Case report

Abstract Introduction Metformin is the most widely used oral antidiabetic, which belongs to the biguanide pharmacological group. Metformin-associated lactic acidosis (MALA) is a rare event with an incidence of approximately 19 cases per 100,000 patient-years. The risk of developing lactic acidosis, when taking metformin is enhanced by several factors such as: age > 65 years; concomitant diseases that have the ability to induce hypoxemia (chronic renal failure, congestive heart failure, cardiogenic shock, severe lung disease, sepsis, advanced liver disease, history of lactic acidosis); an excessive alcohol consumption; an administration of iodinated contrast agents. Clinical Case A 46-year-old man was urgently admitted with the following symptoms: drowsiness, repeated vomiting, lethargy, dizziness. The symptoms started after he administered outpatient and at own initiative 50 tablets of metformin, each tablet contains a dose of 500 mg (total dose 25g). Concomitant pathologies: diagnosed with Type 2 Diabetes for 8 years; Toxic liver cirrhosis, compensated Child-Pugh A (recently diagnosed); hypertension; CKD G3aA2 KDIGO. The patient's condition at admission was assessed as extremely serious, Glasgow scale - 11 points, mild hypertension, tachycardia, tachypnea. The paraclinical investigations revealed the presence of metabolic acidosis, but with lactate <5 mmol/l; the progressive renal dysfunction with creatinine values in the first 24 hours up to 1184 µmol/l, urea – 24.5 mmol/l; a severe hypoglycemia - 1.68 mmol/l; a moderate cytolytic syndrome; a cholestatic syndrome, an inflammatory and hepatoprive syndrome; coagulation disorders; a pancreatic dysfunction. In the context of the evident increase of urea and creatinine, the decision was made to initiate the intermittent hemodialysis, a total of 14 sessions were required during hospitalization. The particularity of this case is represented by the absence of lactic acidosis, despite metformin intoxication with altered neurological status, acute renal failure, developed due to chronic kidney disease, liver cirrhosis of toxic etiology and severe hypoglycemia. Conclusion Metformin should be administered with caution in patients with multiple comorbidities. Metformin intoxication can induce lactic acidosis with an increased risk of serious, potentially fatal adverse events. It is essential to identify metformin intoxication as early as possible, with prompt initiation of renal replacement measures and dynamic monitoring of biochemical parameters.

The influence of motion-compensated reconstruction on coronary artery analysis for a dual-layer detector CT system: a dynamic phantom study.

Cardiac motion artifacts hinder the assessment of coronary arteries in coronary computed tomography angiography (CCTA). We investigated the impact of motion compensation reconstruction (MCR) on motion artifacts in CCTA at various heart rates (HR) using a dynamic phantom. An artificial hollow coronary artery (5-mm diameter lumen) filled with iodinated contrast agent (400 HU at 120 kVp), positioned centrally in an anthropomorphic chest phantom, was scanned using a dual-layer spectral detector CT. The artery was translated at constant horizontal velocities (0-80mm/s, increment of 10mm/s). For each velocity, five CCTA scans were repeated using a clinical protocol. Motion artifacts were quantified using the in-plane motion area. Regression analysis was performed to calculate the reduction in motion artifacts provided by MCR, by division of the slopes of non-MCR and MCR fitted lines. Reference mean (95% confidence interval) motion artifact area was 24.9 mm2 (23.8, 26.0). Without MCR, motion artifact areas for velocities exceeding 20mm/s were significantly larger (up to 57.2 mm2 (40.1, 74.2)) than the reference. With MCR, no significant differences compared to the reference were shown for all velocities, except for 70mm/s (29.0 mm2 (27.0, 31.0)). The slopes of the fitted data were 0.44 and 0.04 for standard and MCR reconstructions, respectively, resulting in an 11-time motion artifactreduction. MCR may improve CCTA assessment in patients by reducing coronary artery motion artifacts, especially in those with elevated HR who cannot receive beta blockers or do not attain the targeted HR. This vendor-specific motion compensation reconstruction may improve coronary computed tomography angiography assessment in patients by reduction of coronary artery motion artifacts, especially in those with elevated various heart rates (HR) who cannot receive beta blockers or do not attain the targeted HR. • Motion artifacts are known to hinder the assessment of coronary arteries on coronary CT angiography (CCTA), leading to more non-diagnostic scans. • This dynamic phantom study shows that motion compensation reconstruction (MCR) reduces motion artifacts at various velocities, which may help to decrease the number of non-diagnostic scans. • MCR in this study showed to reduce motion artifacts 11-fold.

Kompresivna priroda retrosternalne strume

Mediastinal masses originate from the structures of the mediastinum or neck organs and can represent primary benign or malignant tumors, as well as metastases. In most cases, they are detected through radiological imaging, such as an X-ray of the enlarged mediastinum. In the differential diagnostic approach, the acronym "the terrible T" (thymoma, teratoma, terrible lymphoma, and thyroid) is useful. A retrosternal goiter with its compressive effect can lead to changes in the voice, difficult speaking, tracheal compression, and potentially superior vena cava syndrome. Additionally, visualization techniques, thyroid hormones, and tumor markers can be helpful in the diagnostic process. We presented a patient who, during a meal, stopped eating, lost consciousness, and experienced asystole. Due to a chest injury sustained during resuscitation, a computerized tomography (CT) scan was performed. The CT scan revealed a nodular formation in the right lobe of the thyroid gland that extends through the upper thoracic aperture behind the sternum, exerting a pronounced compressive effect on the trachea. Based on the examination, it was concluded that the patient has a goiter with retrosternal and mediastinal extension, accompanied by thyrotoxicosis, which was most likely induced by the iodine contrast agent. Thyrostatic therapy was initiated, followed by surgical treatment of the retrosternal goiter. Computed tomography is the most accessible form of imaging for preoperative assessment of goiter position and its extent, while surgery remains the gold standard for treating symptomatic retrosternal goiters.

Effects of Iodinated Contrast-enhanced CT on Urinary Iodine Levels in Postoperative Patients with Differentiated Thyroid Cancer.

This study aims to observe the fluctuating urine iodine levels in patients with differentiated thyroid cancer (DTC) following iodinated contrastenhanced computed tomography (eCT) scans. The presence of iodine in iodinated contrast agents (ICAs) can impede the effectiveness of radioactive iodine treatment (RAIT) and diagnostic scans in individuals diagnosed with DTC, as it can engage in competitive interactions with 131I. According to established guidelines, it is recommended to postpone RAIT for a period of three to four months in individuals who have had prior exposure to ICAS. The measurement of spot urine iodine concentration is a valuable indicator for assessing the overall iodine content throughout the body. The objective is to identify the optimal timing for administering postoperative RAIT in DTC patients. At various time points after surgery, a cohort of 467 random urine samples (126 male samples, 341 female samples, age (45±12 years)) was obtained from 269 DTC patients. The samples were analyzed for urinary iodine and urinary creatinine levels, and the urinary iodine/urine creatinine ratio (I/Cr) was computed. All samples were divided into two groups according to whether eCT before operation: the non-enhanced CT (eCT-) group and the enhanced CT (eCT+) group. The urine samples in the eCT- group were categorized into four subgroups according to the duration of strict low iodine diet (LID): (eCT-I+) no LID; (eCT-I-2W) 2 weeks of LID; (eCT-I-4W) 4 weeks of LID; and (eCT-I-6W) 6 weeks of LID. The last three groups were merged into the eCT- and effective LID group (eCT- I-). The urine samples from the eCT+ group were categorized into five subgroups: (0.5M eCT+)0.5 month after eCT+; (1M eCT+)1 month after eCT+; (2M eCT+) 2 months after eCT+; (3M eCT+) 3 months after eCT+; (≥4M eCT+) ≥4 months after eCT+. In addition, the patients within 2 months after eCT+ were divided into 2 groups according to their LID: no effective LID group (eCT+ I+) and effective LID group (eCT+ I-). Utilizing the Kruskal-Wallis and Mann-Whitney U rank sum tests, the differences in I/Cr between groups were compared. In the eCT-group, the I/Cr ratios of eCT-I-2W, eCT-I-4W, and eCT-I-6W were significantly lower than those of eCT-I+ (χ2 values: 4.607.99, all P 0.05). However, there was no significant difference in I/Cr between eCT-I-2W, eCT- I-4W, and eCT-I-6W (2 values: 0.591.31, all P > 0.05). Significantly higher I/Cr values were observed in 0.5M eCT+ and 1M eCT+ than in eCT-I+ (χ2 values: 3.22 and 2.18, respectively, all P<0.05). There was no significant difference in I/Cr between 2M eCT+ and eCT-I+ (χ2 = 0.76, P = 0.447). The I/Cr rations of 3M eCT+, ≥4M eCT+ were not significantly different with eCT-I- (χ2 values: 1.76; 0.58; all P > 0.05). However, they were considerably lower than eCT-I+ (χ2 values: 7.03; 5.22; all P<0.05). The I/Cr for patients who underwent eCT within two months (eCT+ I-, eCT+ I+) did not differ significantly (χ2 = 1.79, P = 0.073). For patients who are considering receiving radioactive iodine therapy (RAIT) following a diagnosis of differentiated thyroid cancer (DTC), it is recommended that the interval between RAIT treatment and enhanced computed tomography [eCT] scans be conducted at least three months.

Investigation on Risk Factors of Acute Kidney Injury after Iodine Contrast Agent CT Examination

Investigation on Risk Factors of Acute Kidney Injury after Iodine Contrast Agent CT Examination

Safety of Administering Intravenous CT Contrast Agents Repeatedly or Using Both CT and MRI Contrast Agents on the Same Day: An Animal Study.

To investigate molecular and functional consequences of additional exposures to iodine- or gadolinium-based contrast agents within 24 hours from the initial intravenous administration of iodine-based contrast agents through an animal study. Fifty-six Sprague-Dawley male rats were equally divided into eight groups: negative control, positive control (PC) with single-dose administration of CT contrast agent, and additional administration of either CT or MR contrast agents 2, 4, or 24 hours from initial CT contrast agent injection. A 12 µL/g of iodinated contrast agent or a 0.47 µL/g of gadolinium-based contrast agent were injected into the tail vein. Serum levels of blood urea nitrogen, creatinine, cystatin C (Cys C), and malondialdehyde (MDA) were measured. mRNA and protein levels of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated. Levels of serum creatinine (SCr) were significantly higher in repeated CT contrast agent injection groups than in PC (0.21 ± 0.02 mg/dL for PC; 0.40 ± 0.02, 0.34 ± 0.03, and 0.41 ± 0.10 mg/dL for 2-, 4-, and 24-hour interval groups, respectively; P < 0.001). There was no significant difference in the average Cys C and MDA levels between PC and repeated CT contrast agent injection groups (Cys C, P = 0.256-0.362; MDA, P > 0.99). Additional doses of MR contrast agent did not make significant changes compared to PC in SCr (P > 0.99), Cys C (P = 0.262), and MDA (P = 0.139-0.771) levels. mRNA and protein levels of KIM-1 and NGAL were not significantly different among additional CT or MR contrast agent groups (P > 0.05). A sufficient time interval, probably more than 24 hours, between repeated contrast-enhanced CT examinations may be necessary to avoid deterioration in renal function. However, conducting contrast-enhanced MRI on the same day as contrast-enhanced CT may not induce clinically significant kidney injury.

Does Iodinated Contrast Agent Affect Oxidative Stress? Observational Study

Does Iodinated Contrast Agent Affect Oxidative Stress? Observational Study

Role of Magnetic Resonance Imaging in Transcatheter Structural Heart Disease Interventions

Minimally invasive and catheter-based therapies are increasingly being used in patients with structural heart diseases (SHD). Echocardiography and Contrast-enhanced Computed Tomography Angiography (CE-CTA) are used in procedural planning for evaluating suitability of these interventions in SHD. However, some patients may not be able to undergo CE-CTA due to renal impairment or history of severe contrast reaction to iodinated contrast agents. Cardiac magnetic resonance (CMR) imaging can be used as an alternative noninvasive cross- sectional imaging modality in such patients. Measurements required for planning transcatheter SHD interventions such as annular and vessel size, as well as qualitative and quantitative functional information, such as flow across a valve or structural defect can be obtained with MRI. Phase contrast MRI can be used to quantify intracardiac shunts. In this article, we discuss the emerging indications of MRI in preoperative assessment for minimally invasive and transcatheter interventions in structural heart diseases.

Usporedba između magnetne rezonancije dojki i kontrastne mamografije

Introduction: Imaging modalities such as contrast-enhanced mammography (CEM) and magnetic resonance imaging (MRI) are used as valuable tools for understanding breast pathology. They enable early detection of breast cancer, provide a precise insi-ght into theslesions, and facilitate the monitoring of responses to treatment. Modern CEM improves the detection of breast abnor-malitiesfusing contrast agents and the combination of higher energy levels in a single examination. MRI uses magnetic fields and coils to produce detailed images of breast tissue in high-risk cases, and to evaluate suspicious findings with other imaging methods using different sequences.Aim of the paper: The aim of the paper is to introduce CEM and MRI separately, while also identifying the strengths and weaknesses of each technique. This will facilitate their direct comparison.Discussion: CEM excels in detecting multifocal or contralateral lesions, assessing response to treatment, and identifying microcalcifications. Combining the power of mammography and contrast, CEM has the disadvantages of higher radiation dose, artifacts, and possible reactions to the use of iodinated contrast agent. In contrast, MRI provides detailed images, better lesion identification and treatment assessment and possesses exceptional contrast for breast soft tissue evaluation. It has proven invalua-ble for assessing implant condition and detecting lesions not seen on mammography images. This is crucial for high-risk cases and hiddenstumours. However, MRI has limitations such as artifacts and cost. CEM is a viable alternative to MRI, with high sensitivity.Conclusion: The combined use of CEM and MRI has the potential to transform breast cancer treatment by improving diagnostic accuracy and enabling more personalized treatment approaches, especially in challenging cases, and among high-risk populations with dense breast tissue. With continued technological advances and standardization efforts, CEM and MRI will continue to play a critical role in early cancer detection, lesion characterization, and treatment monitoring, ultimately improving patient outcomes in the field of breast cancer.

Iopamidol Abatement from Waters: A Rigorous Approach to Determine Physicochemical Parameters Needed to Scale Up from Batch to Continuous Operation.

The abatement of iopamidol (IPM), an X-ray iodinated contrast agent, in aqueous solution using powdered activated carbon (PAC) as a sorbent was investigated in the present work. The material was characterized by various analytical techniques such as thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis, dynamic light scattering, and zeta potential measurements. Both thermodynamic and kinetic experiments were conducted in a batch apparatus, and the effects of the initial concentration of IPM, the temperature, and the adsorbent bulk density on the adsorption kinetics were investigated. The adsorption isotherms were interpreted well using the Langmuir model. Moreover, it was demonstrated that IPM adsorption on PAC is spontaneous and exothermic (ΔH0 = -27 kJ mol-1). The adsorption kinetic data were described using a dynamic intraparticle model for fluid-solid adsorption kinetics (ADIM) allowing determination of a surface activation energy Es = 6 ± 1 kJ mol-1. Comparing the experimental results and the model predictions, a good model fit was obtained.

Liposome-camouflaged iodinated mesoporous silica nanoparticles with high loading capacity, high hemodynamic stability, high biocompatibility and high radiopacity

Due to their low osmolality and high tolerability, the highly water-soluble nonionic iodinated contrast agents, such as Ioversol (IV), are widely used as clinical agents for CT imaging. However, their clinical applications still are severely limited by the rapid renal excretion, serious adverse effects especially contrast-induced nephropathy and inefficient targetability. Various nanocarriers have demonstrated tremendous potential for achieving high imaging efficiency and low side effects. However, few nanoparticulate contrast agents can simultaneously integrate the desirable functions for imaging, including high loading capacity of iodine, high structure stability for systemic circulation, high biocompatibility and high radiopacity. Herein, we designed and prepared a kind of new radiopaque liposome-camouflaged iodinated mesoporous silica nanoparticles (OIV-MSNs@Liposomes) as contrast agents in CT imaging. Their composition, structure, morphology, biocompatibility and physicochemical properties as well as in vitro radiopacity were investigated in detail. The results indicated that OIV-MSNs@Liposomes can integrate their individual advantages of liposomes and MSNs, thus exhibiting great potential for use in the CT imaging. Considering the simple preparation process and readily available starting materials as well as enhanced biosafety and high performance in X-ray attenuation, the strategy reported here offers a versatile route to efficiently deliver highly water-soluble nonionic iodinated contrast agents for enhanced CT imaging, which are unattainable by traditional means.

Acute Adverse Events After Iodinated Contrast Agent Administration of 359,977 Injections: A Single-Center Retrospective Study.

To assess the effects of patient variables, examination variables, and seasonality on allergic-like and physiologic reactions to iodinated contrast material (ICM). All ICM-enhanced computed tomography (CT) examinations performed from June 1, 2009, to May 9, 2017, at our institution were included. Reactions were identified and categorized as allergic-like or physiologic and mild, moderate, or severe. The effect of patient and examination variables on reactions was evaluated by logistic regression models. A total of 359,977 CT examinations performed on 176,886 unique patients were included. A total of 1150 allergic-like reactions (0.32%; 19 severe [0.005%]) and 679 physiologic reactions (0.19%; 3 severe [0.0008%]) occurred. On multivariable analysis, iopromide had higher rates of reactions compared with iohexol (allergic-like reactions: odds ratio [OR], 3.07 [95% CI, 2.37 to 3.98], P<.0001; physiologic reactions: OR, 2.60 [1.92 to 3.52], P<.0001). Non-White patients had higher rates of reactions compared with White patients (allergic-like reactions: OR, 1.77 [1.36-2.30], P<.0001; physiologic reactions: OR, 1.76 [1.27-2.42], P=.0006). Patient age, sex, prior ICM reaction, ICM dose, CT location, and CT type were also significantly associated with reactions. No significant seasonality trend was observed (P=.07 and .80). Non-White patients and patients administered iopromide had higher rates of acute reactions compared with White patients and patients administered iohexol. Younger patients (<50 years vs 51 to 60 years), female sex, history of ICM allergy or other allergies, ICM dose, and contrast-enhanced CT location and type also correlated with higher acute reaction rates.

A 57-Year-Old Woman Present with Acute Delirium and Fever

&lt;p&gt;燒合併急性譫妄（Acute delirium），臨床上常被認為感染導致。本個案57歲女性，三天前因發燒、意識混亂與腹瀉，初步臆測診斷為細菌性腸炎造成譫妄，經糞便、血液細菌培養、腦部電腦斷層、腦脊髓液檢查、腦波與皮質酮（cortisol）檢驗均正常，抗生素治療下仍高燒不退、腹瀉、心搏過速，急劇意識昏迷併呼吸衰竭及全身抽搐。回顧此個案罹患甲狀腺機能亢進又擅自停藥，近期使用Xenetix碘顯影劑，當同時出現高燒、意識改變、腸胃肝膽障礙與心搏過速，按照甲狀腺風暴（Thyroid storm）診斷評分100分應高度懷疑甲狀腺風暴，盡快給予&amp;szlig;交感神經阻斷劑、降低甲狀腺激素合成、糖皮質類固醇、含碘製劑治療，經治療後個案意識與精神症狀獲得改善並順利出院。本篇教學著重如何快速鑑別診斷並牢記甲狀腺風暴評分項目與相關誘發因子，進而早期診斷與積極治療，可降低死亡率及多重器官衰竭，達到個案回歸日後自我照護能力。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Acute delirium is usually caused by infection, clinically. The case in this study is a 57-year-old woman with fever, confusion, and diarrhea for 3 days. The initial diagnosis was delirium caused by bacterial enteritis. Examinations of feces, blood bacteria culture, computed tomography scan, cerebrospinal flu-id, electroencephalography, and cortisol were all normal. However, high fever, diarrhea, tachycardia, acute unconsciousness with respiratory failure, and general convulsions persisted despite antibiotic treatment was applied. After recalling medical history the patient was suffered from hyperthyroidism and discontinued medication without permission. Furthermore, a Xenetix iodine contrast agent was re-cently administered while symptoms such as high fever, altered consciousness, gastrointestinal hepa-tobiliary disturbance, and tachycardia occurred simultaneously. Therefore, the possibility of a thyroid storm became apparent after applying the thyroid storm 100-point diagnosis scale evaluation. As such, &amp;szlig; sympathetic blockers, reduction of thyroid hormone synthesis, glucocorticoids, and preparations con-taining iodine were administered immediately. After treatments, the consciousness and mental symp-toms of the patient were improved and then successfully discharged. This case suggests that a rapid differential diagnosis by remembering the thyroid storm grading scale as well as relevant predisposing factors shell be considered in early diagnosis. Furthermore, proactive treatments could be utilized to reduce mortality rate and the possibility of multiple organ failure, thereby allowing patients to recover self-care ability in the future.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

A comparison of image quality of cerium oxide nanoparticles and iodine contrast agents in computed tomography scan

Computed tomography (CT) scan, with iodine-based contrast, produces good image quality by improving the visualisation of relatively low-contrast internal body structures. However, the impact of using iodinated difference should be considered in patients susceptible to contrast allergy and renal impairment. Therefore, alternative contrast materials, such as cerium oxide nanoparticles (CeO2 NPs), must be used, with biocompatible properties and strong X-ray attenuation capabilities. This study compared the CT scan image quality of CeO2 NPs and iodinated contrast agents. This experimental study started by preparing a suspension of CeO2 NPs and iodine in aquabidest at a concentration of 500 ppm. The suspension was scanned using a CT scan with a helical scanning method. The exposure coefficient parameters were set for the tube voltage of 80 kV, Field of View of 28 cm, slice thickness of 5 mm, and tube current time of 150 mAs, 200 mAs, and 250 mAs. Then, CT images in DICOM data format were processed using MicroDICOM Viewer software. The quality of the CT scan images was analysed based on the CT number value, noise level, and contrast resolution. The images of CeO2 nanoparticles have higher CT values, lower noise levels, and better contrast resolution than those of iodine contrast agents. The results show that the CT image results of CeO2 NPs have better quality than those of iodine-containing contrast agents.

Iodixanol as a New Contrast Agent for Cyanoacrylate Embolization: A Preliminary In Vivo Swine Study.

N-butyl cyanoacrylate (NBCA) is a lipophilic, permanent embolic glue that must be opacified for fluoroscopic guidance. Empirically, lipophilic Lipiodol Ultra Fluid® (LUF) has been added to produce a single-phase physically stable mixture. Varying the dilution ratio allows control of glue polymerization kinetics. LUF is far more costly than water-soluble iodinated contrast agents (ICAs). Our purpose was to evaluate whether a water-soluble nonionic iso-osmolar ICA could be used instead. We embolized both renal arteries of six swine using 1:3 NBCA-LUF or NBCA-iodixanol in 1:1, 1:3, and 1:7 ratios. We used both micro-computed tomography to assess the distality of glue penetration and indexed cast ratio and histology to assess distality, arterial obliteration, vessel-wall damage, and renal-parenchyma necrosis. Glue-LUF produced significantly greater indexed cast ratio and renal-artery ROI values and a significantly shorter cast-to-capsule distance. The injected volume was significantly greater with 1:7 iodixanol than with the other mixtures. No significant differences were found for histological evidence of artery obliteration, vessel-wall damage, or renal-parenchyma necrosis. This is the first study dealing with ICA alone as a contrast agent for cyanoacrylate embolization, compared to LUF. More research is needed to determine whether water-soluble nonionic iodinated agents can be used for human NBCA embolization given the good safety profile, availability, and low cost of ICA.

Accuracy of iodine quantification in dual energy CT: A phantom study across 3 different CT systems

IntroductionNo study has rigorously compared the performances of iodine quantification on recent CT systems employing different emission-based technologies, depending on the manufacturers and models. MethodsA specific bespoke phantom was used for this study, with 12 known concentrations of iodinated contrast agent: 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 10.0, 15.0, 20.0, 30.0 and 50.0 mg/mL. Three different dual-energy scanners were tested: one system using dual-source acquisition (CT#1) and two systems using Fast kilovolt-peak switching technology ± artificial intelligence (AI) reconstruction methods (CT#2 and #3) from two different manufacturers. For each system, helical scans were performed following recommended clinical protocols. Four acquisitions were performed per iodine concentration (mg/mL), and measurements were made on iodine-maps using ROIs. Mean measured values were compared to the known concentrations, and the absolute quantification error (AQE) and the relative percentage error (RPE) were used to compare the performances of each CT. ResultsThe accuracy of the obtained measurements varied depending on the studied model but not on the acquisition mode (dual-source vs kVp switch ± AI). The quantification was more precise at high concentrations. RPE values were below 10 % with CT#2 (kVp switch) and below 25 % with CT#1 (dual-source), but were significantly higher with CT#3 (kVp switch + AI), exceeding 50 % at low concentrations (<3 mg/mL). ConclusionsWith the help of a phantom, we identified variability in the results accuracy depending on the CT model, with sometimes significant deviation. Considering the performances of the different DECT technologies in iodine mapping, dual-source (CT#1) and kVp switch (CT#2) technologies appear more accurate than kVp switch technology combined with deep-learning-based reconstruction (CT#3) especially at low concentrations (<3 mg/mL). Implications for practiceAs the primary and daily user of medical imaging devices, the radiographer role is to be attentive to the performance of imaging systems, particularly when performing quantitative acquisitions like iodine-quantification. In CT quantitative imaging (iodine map), it's essential for radiographers to consider their CT systems as measuring tools, and to be aware of their accuracies and limits.

Mutagenicity assessment of two potential impurities in preparations of 5-amino-2,4,6 triiodoisophthalic acid, a key intermediate in the synthesis of the iodinated contrast agent iopamidol

5-Aminoisophthalic acid and 5-nitroisophthalic acid (5-NIPA) are potential impurities in preparations of 5-amino-2,4,6-triiodoisophthalic acid, which is a key intermediate in the synthesis of the iodinated contrast agent iopamidol. We have studied their mutagenicity in silico (quantitative structure-activity relationships, QSAR) and by the bacterial reverse mutation assay (Ames test). First, the compounds were screened with the tools Derek Nexus™ and Leadscope®. Both compounds were flagged as potentially mutagenic (class 3 under ICH M7). However, contrary to the in silico prediction, neither chemical was mutagenic in the Ames test (plate incorporation method) with or without S9 metabolic activation.

Self-Assembled Nano-CT Contrast Agent Leveraging Size Aggregation for Improved In Vivo Tumor CT Imaging.

Computed tomography (CT) is a widely utilized noninvasive diagnostic tool in clinical practice. However, the commonly employed small molecular iodinated contrast agents (ICAs) in clinical CT imaging have limitations such as nonspecific distribution in body, rapid clearance through kidneys, etc., leading to a narrow imaging time window. In contrast, existing nano-sized ICAs face challenges like structural uncertainty, poor reproducibility, low iodine content, and uniformity issues. In this study, a novel approach is presented utilizing the aggregation-induced emission luminogen (AIEgen) to design and fabricate a kind of monocomponent nano-sized ICA (namely, BioDHU-CT NPs) that exhibits a unique aggregation effect upon activation. The small sized BioDHU-CT nanoparticles exhibit excellent tumor targeting capabilities and can release ICA modified with AIEgen with a high release efficiency up to 88.45%, under the activation of reactive oxygen species highly expressed in tumor regions. The released ICA performs in situ aggregation capability in the tumor region, which can enhance the retention efficiency of CT contrast agents, extending the imaging time window and improving the imaging quality in tumor regions.

Clinical case of 9-month observation of orbital venous varicose with intraluminal thrombus using radiologic methods

A rare clinical case of thrombosis of varicose superior ophthalmic vein in combination with a unilateral venous anomaly of the subcortical region of the brain with successful antithrombotic therapy is presented. Varicose veins of the superior ophthalmic vein are rare (2% of all orbital formations) and are a risk factor for thrombosis.Material and methods. A 41-year-old patient with verified thrombosis of unilateral orbital venous varicose veins was observed for 9 months. Initially, MSCT of the brain and MSCT angiography were performed, then dynamic monitoring was carried out by performing MRI of the brain and MR venography, and finally an ultrasound examination of the orbit was performed.Description of a clinical case. The clinical presentation consisted of a slight non-pulsatile unilateral exophthalmos, mild ptosis, periorbital soft tissue edema, subconjunctival hemorrhage, paraorbital hematoma, and venous dysfunction in the fundus. MSCT and MSCT angiography revealed a thrombus inside the sac of orbital venous varicose veins. The disease was probably secondary in nature, given that it was combined with venous angioma of the subcortical region on the same side. During 9 months of observation, to monitor the effectiveness of therapy, MRI was performed three times before and after contrast enhancement, which showed a gradual decrease in exophthalmos, the size of the thrombus and the varicocele sac, which was accompanied by a gradual improvement in the clinical picture until subjective recovery.Conclusion. MRI was as good an imaging modality as MSCT, and, in our opinion, more preferable due to the absence of radiation exposure and the need for iodine contrast agent.