Clinical safety evaluation of contrast agents based on real-world evidence.

WHAT IS KNOWN AND OBJECTIVE: This study was aimed at comparing the adverse drug reactions (ADRs) arising from the use of iodinated contrast medium (ICM) and gadolinium-based contrast media (GBCM), and to provide a basis for the clinical selection of contrast media. METHODS: Retrospective data for ADR cases occurring from the use of ICM or GBCM during enhanced scanning in computed tomography and magnetic resonance imaging were collected between June/2013 and May/2020 from Wenling Hospital of Traditional Chinese Medicine. Chi-square tests were performed based on the characteristics of patients and the classification of contrast medium. Bonferroni correction was applied to the statistical analyses with multiple comparisons of proportions. RESULTS: Among 27,328 patients who were subjected to enhanced CT scanning, 207 cases (0.76%) showed ICM-related ADRs. Among 16,381 patients who were subjected to enhanced MRI scanning, 25 cases (0.15%) showed ADRs related to GBCM. The incidence of ADR induced by GBCM was significantly lower than ICM-induced ADR (p < 0.01). There were no significant differences in the incidence among different types of ICM, including ioversol and iodixanol, as well as iodixanol from different manufacturers (p > 0.05). Interestingly, the ADR incidence of ICM seemed to be associated with gender, with a significantly higher incidence in females than in male patients, and it was also associated with the age, with a lower occurrence in older (>44 years) compared to younger patients. WHAT IS NEW AND CONCLUSION: With respect to ADR incidence, the safety profile of ICM of different types and different manufacturers was found to be similar in clinical use, warranting no need of specifically choosing imported or more expensive products. While choosing contrast medium type for clinical use, attention should be paid to certain populations, especially to younger and female patients when the patients are about to undergo a contrast-enhanced examination.

Examining the Accuracy of Ultrasound-Guided Lumbar Transforaminal Injection Controlled by Fluoroscopic Imaging in Patients with Lumbar Radiculopathy: A Modified Technique.

AIM: To present a new sonographic approach for lumbar transforamianal injection and compared it with traditional fluoroscopicguided approach. MATERIAL AND METHODS: This interventional clinical study was conducted on 30 patients with a history of radicular lowback pain and a recent MRI indicating root compression. On the prone position, with the curve of ultrasound transducer on the parasagittal oblique position, a peripheral venous catheter (# 16) was advanced to the lamina through out-of-plane technique. Then, the transducer position was changed to axial position and an epidural catheter was placed about 8 cm away from midline and advanced under sonography guide with the in-plane technique to the intervertebral foramen. The level and the situation of needle was controlled with fluoroscopy and documented when the corticosteroid (triamcinolone) was injected. Also, pain scores for patients were documented and analyzed with SPSS-22 software. RESULTS: After controlling with fluoroscopy, from all 38 levels of injection, 36 levels were correctly achieved. Of all 36 injections on right levels, all injections were performed in the correct position (in intervertebral foramen). The patients? pain dramatically decreased during the first month after injection (p < 0.001), but after that, it remained unchanged. CONCLUSION: In our study, transforaminal injection was administered using the modified new technique, which was found to be safe and accurate in comparison with the fluoroscopy, as the popular gold standard technique.

A systematic review of cost-effectiveness analyses across the acute kidney injury landscape.

Introduction: Acute kidney injury (AKI) is a complex and common condition associated with increased morbidity, mortality, and costs. Evidence from cost-effectiveness analysis (CEA) have targeted various aspects of AKI including detection with biomarkers, treatment with renal replacement therapy, and prevention when using contrast media. However, there has not been a systematic review of these studies across the entirety of AKI.Areas covered: PubMed, Embase, and Cochrane library were used to identify CEA studies that involved AKI from 2004 onwards. These studies compared AKI treatment through renal replacement therapies (n = 6), prevention of contrast-induced-AKI (CI-AKI) using different media (n = 3), and diagnosis with novel biomarkers (n = 2). Treatment strategies for AKI focused on continuous versus intermittent renal replacement therapy. While there was no consensus, the majority of studies favored the continuous form. For contrast media, both studies found iodixanol to be cost-effective compared to iohexol for preventing CI-AKI. Additionally, novel biomarkers showed potential to be cost-effective in risk assessment and detection of AKI.Expert opinion: Consistent criteria such as a lifetime time horizon would allow for better model comparisons. Further research on clinical parameters to capture transition probabilities between stages within AKI and progression to downstream kidney disease is needed.

Evaluation of Low-Dose Multidetector Computed Tomography Whole Gastroenterography With Oral Administration of Contrast Agents.

PURPOSE: To evaluate the degree of gastric, enteric, colonic, and rectal filling in multidetector computed tomography (MDCT) whole gastroenterography. METHODS: In this prospective study involving 124 patients, 78 and 46 patients underwent MDCT whole gastroenterography using positive and neutral oral contrast agents, respectively. The degree of filling of the stomach, small and large bowel, was qualitatively analyzed by experienced radiologists using a 3-point scoring system. RESULTS: The majority of patients received a score of ≥2 for small intestine filling using both positive and neutral contrast agents (90.5% and 78.2%, respectively), and <9% of the patients had a score of 0. The highest score for the degree of filling in the small intestine was observed in the ileum, followed by the duodenum and jejunum. There was a significant difference in the degree of filling achieved with positive and neutral contrast agents in the duodenum (P = .013) and jejunum (P = .047). More than 74% of cases had an optimal filling of the stomach, whereas >80% of the cases had an optimal filling of the colorectal segments. Only ≤5.1% had a score of 0 for the analyzed segments of the colorectum. Positive and neutral contrast agents were associated with similar degree of filling in the stomach and colon segments without a significant difference in the extent of contrast agent filling (P > .05). CONCLUSIONS: Multidetector computed tomography whole gastroenterography was found to be a simple, safe, noninvasive, painless, and effective modality for the diagnosis of stomach and bowel complications in clinical settings.

Performance evaluation of two iterative reconstruction algorithms, MBIR and ASIR, in low radiation dose and low contrast dose abdominal CT in children.

BACKGROUND: The adverse effect of low-dose CT on image quality may be mitigated using iterative reconstructions. The purpose of this study was to evaluate the performance of the full model-based iterative reconstruction (MBIR) and adaptive statistical reconstruction (ASIR) algorithms in low radiation dose and low contrast dose abdominal contrast-enhanced CT (CECT) in children. METHODS: A total of 59 children (32 males and 27 females) undergoing low radiation dose (100kVp) and low contrast dose (270 mgI/ml) abdominal CECT were enrolled. The median age was 4.0 years (ranging from 0.3 to 13 years). The raw data were reconstructed with MBIR, ASIR and filtered back-projection (FBP) algorithms into 6 groups (MBIR, 100%ASIR, 80%ASIR, 60%ASIR, 40%ASIR and FBP). The CT numbers, standard deviations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of liver, pancreas, kidney and abdominal aorta were measured. Two radiologists independently evaluated the subjective image quality including the overall image noise and structure display ability on a 4-point scale with 3 being clinically acceptable. The measurements among the reconstruction groups were compared using one-way ANOVA. RESULTS: The overall image noise score and display ability were 4.00 ± 0.00 and 4.00 ± 0.00 with MBIR and 3.27 ± 0.33 and 3.25 ± 0.43 with ASIR100%, respectively, which met the diagnostic requirement; other reconstructions couldn't meet the diagnostic requirements. Compared with FBP images, the noise of MBIR images was reduced by 62.86-65.73% for the respective organs (F = 48.15-80.47, P < 0.05), and CNR increased by 151.38-170.69% (F = 22.94-38.02, P < 0.05). CONCLUSIONS: MBIR or ASIR100% improves the image quality of low radiation dose and contrast dose abdominal CT in children to meet the diagnostic requirements, and MBIR has the best performance.

Increased fibrotic signaling in a murine model for intra-arterial contrast-induced acute kidney injury.

Contrast-induced acute kidney injury (CI-AKI) is a vexing problem, and more than 70 million patients undergo studies using iodinated contrast. The molecular mechanisms responsible for CI-AKI are poorly understood. The goal of the present article was to determine the role of transforming growth factor-ß1 (TGF-ß1)/mothers against decapentaplegic homolog (SMAD)3 and associated collagen expression in a murine model of intra-arterial CI-AKI. The murine model of CI-AKI after intra-arterial contrast agent administration was created by first performing a partial nephrectomy to induce chronic kidney disease. Twenty-eight days later, 100 µL of contrast agent [iodixanol (320 mg/mL)] or saline were administered via the carotid artery. Two days after contrast administration, compared with saline, average serum creatinine was significantly elevated (P < 0.05). In the cortex, there was a significant increase in phosphorylated SMAD3 and gene expression of TGF-ß1, TGF-ß receptor type I, and TGF-ß receptor type II at day 2 in the contrast group compared with the saline group. Average gene expressions of connective tissue growth factor, matrix metalloproteinase-2 and -9, and collagen type I-α and type IV-α were significantly increased at 2 days after contrast administration (all P < 0.05). Moreover, there was a decrease in Ki-67 staining in the cortex, with an increase in terminal deoxynucleotidyl transferase dUTP nick-end labeling in the cortex and medulla after contrast administration (P < 0.05). In the murine intra-arterial CI-AKI model, there was increased hypoxia and TGF-ß1/SMAD3 pathway activation and collagen expression, resulting in renal fibrosis. Together, these results suggest that the TGF-ß1/SMAD3 pathway could be a potential target in alleviating tissue fibrosis in CI-AKI.

Iodinated poly(p-dioxanone) as a facile platform for X-ray imaging of resorbable implantable medical devices.

Currently, implantable fibrous medical devices still suffer from invisibility under current clinical imaging techniques. To address this problem, 2, 3, 5-triiodobenzoic acid (TIBA) was recruited as a contrast agent, and then a set of iodinated poly(p-dioxanone) (PPDO) fibers was fabricated via melt-spinning hybrid blends of PPDO with TIBA (PPDO/TIBA). The impact of TIBA content on the rheological behavior of blends was evaluated firstly. The physical, chemical, and thermal properties of PPDO/TIBA fibers were investigated accordingly by SEM, FTIR, DSC, and TGA. Moreover, the radiopaque property of PPDO/TIBA hybrid fibers as a potential radio-opacifying platform for medical devices was verified in vitro and in vivo. Finally, the accumulated release results of the hybrid fibers during in vitro degradation indicate the continual X-ray visibility of the hybrid fibers maintains for 22 days. This intriguing iodinated platform may pave the way for constructing fibrous materials with in-situ X-ray tracking property.

Application of Low Tube Voltage, Low-concentration Contrast Agent Using a 320-row CT in Coronary CT Angiography: Evaluation of Image Quality, Radiation Dose and Iodine Intake.

The effect of low voltage and low concentration contrast agent on image quality of coronary CT angiography, radiation dose and iodine intake was evaluated. A total of 121 patients with body mass index (BMI) <26 kg/m2 and heart rate (HR) <70 beats/min were randomly divided into four groups: group A (n=31, 80 kVp, 270 mgI/mL); group B (n=33, 100 kVp, 270 mgI/mL); group C (n=30, 100 kVp, 320 mgI/mL); group D (n=27, 100 kVp, 400 mgI/mL). The automatic current modulation system and the iterative algorithm for reconstruction were adopted in each group. The CT values and SD values of the aortic root (AR), subcutaneous fat, left coronary artery opening (LCA), and right coronary artery opening (RCA) were measured in all groups, the signal-to-noise ratio (SNR) and contrast noise ratio (CNR) were calculated, and effective radiation dose and iodine intake were recorded. The subjective assessment for image quality was performed by two physicians using a 4-point scale. The results were compared using the one-way ANOVA and rank sum tests. The image quality of the four groups met the clinical diagnostic requirements. The CT values of AR in groups A, B, C, and D were 537.6±71.4, 447.2±81.9, 445.2±64.9 and 518.5±94.9 Hu, respectively, with no significant difference between group A and group D, or between group B and group C, while CT values in groups B and C were significantly lower than those in groups A and D (P<0.05). In groups A, B, C, and D, the LCA SNR values were 22.7±9.1, 23.3±9.1, 23.3±7.7 and 26.6±8.9, and the RCA CNR values were 26.9±9.8, 28.5±11.4, 27.7±8.8 and 32.1±10.6, respectively. The AR visual scores in groups A, B, C and D were 3.8±0.2, 3.9±0.3, 3.9±0.3 and 4.0±0.3, respectively. There were no significant differences in SNR, CNR and visual score among the four groups (P>0.05). The radiation doses in groups A, B, C and D were 2.6±1.4, 3.6±1.8, 4.9±3.5 and 4.9±2.8 mSv, respectively. The radiation dose in group A was significantly less than that in the rest three groups (P<0.05). The iodine intakes in groups A, B, C and D were 14.9±1.5, 15.0±1.5, 17.7±2.0 and 18.1±2.5 g, respectively. There was no significant difference in the intake of iodine between groups C and D, or between groups A and B, while iodine intake in groups A and B were significantly reduced as compared with that in groups C and D (P<0.05). It was concluded that for patients with low BMI and controlled HR, compared to 100 kVp tube voltage combined with multiple concentration contrast agents, 80 kVp combined with 270 mgI/mL contrast agent is enough to ensure the quality of the images, and can reduce the radiation dose significantly, while reducing the amount of iodine intake notably, thus reducing the incidence of adverse reaction.

Subclinical Contrast-Induced Acute Kidney Injury in Patients Undergoing Cerebral Computed Tomography.

INTRODUCTION: The nephrotoxicity of modern contrast media remains controversial. Novel biomarkers of kidney damage may help in identifying a subclinical structural renal injury not revealed by widely used markers of kidney function. OBJECTIVE: The aim of this study was to investigate clinical (contrast-induced acute kidney injury [CI-AKI]) and subclinical CI-AKI (SCI-AKI) after intra-arterial administration of Iodixanol and Iopamidol in patients with an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2. METHODS: This is a prospective observational monocentric study. Urinary sample was collected at 4-8 h after contrast medium exposure to measure neutrophil gelatinase associated lipocalin (NGAL) and the product tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 ([TIMP-2] × [IGFBP7]), while blood samples were collected at 24 and 48 h after exposure to measure serum creatinine. RESULTS: One hundred patients were enrolled, of whom 53 were exposed to Iodixanol and 47 to Iopamidol. Patients in Iodixanol and Iopamidol groups were comparable in terms of demographics, pre-procedural and procedural data. No patient developed CI-AKI according KDIGO criteria, while 13 patients reported SCI-AKI after exposure to iodine-based medium contrast (3 patients in Iodixanol group and 10 patients in Iopamidol group), defined by positive results of NGAL and/or [TIMP-2] × [IGFBP7]. A positive correlation was found between NGAL and [TIMP-2] × [IGFBP7] in the analysed population (Spearman's rho 0.49, p < 0.001). In logistic regression analysis, Iopamidol exposure showed higher risk for SCI-AKI compared to Iodixanol (OR 4.5 [95% CI 1.16-17.52], p = 0.030), even after controlling for eGFR and volume of contrast medium used. CONCLUSIONS: This study showed that intra-arterial modern contrast media administration may have a nephrotoxic effect in a population without pre-existing chronic kidney disease. Further investigations on larger scale are warranted to confirm if Iopamidol exposed patients to increased risk of SCI-AKI compared to Iodixanol.

Impact of CT Injector Technology and Contrast Media Viscosity on Vascular Enhancement: Evaluation in a Circulation Phantom.

OBJECTIVE: To assess the impact of piston-based vs peristaltic injection system technology and contrast media viscosity on achievable iodine delivery rates (IDRs) and vascular enhancement in a pre-clinical study. METHODS: Four injectors were tested: MEDRAD® Centargo, MEDRAD® Stellant, CT Exprès®, and CT motion™ using five contrast media [iopromide (300 and 370 mgI ml-1), iodixanol 320 mgI ml-1, iohexol 350 mgI ml-1, iomeprol 400 mgI ml-1]. Three experiments were performed evaluating achievable IDR and corresponding enhancement in a circulation phantom. RESULTS: Experiment I: Centargo provided the highest achievable IDRs with all tested contrast media (p < 0.05). Iopromide 370 yielded the highest IDR with an 18G catheter (3.15 gI/s); iopromide 300 yielded the highest IDR with 20G (2.70 gI/s) and 22G (1.65 gI/s) catheters (p < 0.05).Experiment II: with higher achievable IDRs, piston-based injectors provided significantly higher peak vascular enhancement (up to 48% increase) than the peristaltic injectors with programmed IDRs from 1.8 to 2.4 gI/s (p < 0.05).Experiment III: with programmed IDRs (e.g. 1.5 gI/s) achievable by all injection systems, Centargo, with sharper measured bolus shape, provided significant increases in enhancement of 34-73 HU in the pulmonary artery with iopromide 370 (p < 0.05). CONCLUSION: The tested piston-based injection systems combined with low viscosity contrast media provide higher achievable IDRs and higher peak vascular enhancement than the tested peristaltic-based injectors. With equivalent IDRs, Centargo provides higher peak vascular enhancement due to improved bolus shape. ADVANCES IN KNOWLEDGE: This paper introduces a new parameter to compare expected performance among contrast media: the concentration/viscosity ratio. Additionally, it demonstrates previously unexplored impacts of bolus shape on vascular enhancement.

A prospective study of contrast preservation using ultra-low contrast delivery technique versus standard automated contrast injector system in coronary procedures.

BACKGROUND: We aimed to assess the decrease in contrast media volume (CMV) with ultra-low contrast delivery technique (ULCD) developed at our institution versus the usual automated contrast injector system (ACIS) contrast delivery in coronary procedures. METHODS: We analyzed the amount of contrast given in the consecutive 204 patients of the operators who use ULCD technique versus consecutive 200 patients of the other operators who use ACIS without ULCD technique for coronary angiograms and/or percutaneous coronary interventions (PCIs) from May 2017 to July 2018 at our center. We calculated the mean CMV between these groups. RESULTS: We observed a significant reduction in mean CMV with ULCD technique versus standard ACIS, respectively: angiogram 24.8 ± 15.8 mL (n = 194) vs 42.3 ± 25.1 mL (n = 200) (p < 0.0001); PCI 23.5 ± 19.7 mL (n = 52) vs 48.2 ± 30.8 mL (n = 16) (p < 0.0070); angiogram with ad hoc PCI 53.4 ± 32.1 mL (n = 23) vs 89.7 ± 35.6 mL (n = 16) (p < 0.0024); and overall angiogram and PCI 27.4 ± 20.5 mL (n = 204) vs 44.9 ± 28.0 mL (n = 181) (p < 0.0001). CONCLUSION: Our study showed a highly significant reduction in CMV using ULCD technique compared to standard ACIS contrast delivery in coronary invasive procedures. Even in the standard ACIS arm, CMV was significantly lower than values reported in literature, possibly due to operators' bias toward contrast preservation.

An augmented patient-specific approach to administration of contrast agent for CT renal angiography

ABSTRACT Purpose This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. Materials and Methods 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). Results Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p< 0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p< 0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. Conclusion Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.

Application of Artificial Intelligence-based Image Optimization for Computed Tomography Angiography of the Aorta With Low Tube Voltage and Reduced Contrast Medium Volume.

PURPOSE: The purpose of this study was to evaluate the impact of artificial intelligence (AI)-based noise reduction algorithm on aorta computed tomography angiography (CTA) image quality (IQ) at 80 kVp tube voltage and 40 mL contrast medium (CM). MATERIALS AND METHODS: After obtaining institutional review board approval and 8 written informed consents, 60 patients (35 men, 25 women; age range: 18 to 85 y) referred for aorta CTA examination were assigned to 2 groups at random. Group A underwent an 80 kVp protocol with 40 mL CM (320 mg I/mL). Group A reconstructed with iterative reconstruction was named as group A1 and further AI-based noise reduction was named as group A2. Group B was scanned with standard 120 kVp, 80 mL CM, and iterative reconstruction algorithm. The quantitative assessment of IQ included aorta CT attenuation, noise, signal-to-noise ratio, and contrast-to-noise ratio. A 5-point scale (5-excellent, 1-poor) was used by 2 radiologists independently for qualitative IQ analysis. RESULTS: The image noise significantly decreased while signal-to-noise ratio and contrast-to-noise ratio significantly increased in the order of group A1, B, and A2 (all P<0.05). Compared with group B, the subjective IQ score of group A1 was significantly lower (P<0.05), while that of group A2 had no significant difference (P>0.05). The effective dose and CM volume of group A were reduced by 79.18% and 50%, respectively, than that of group B. CONCLUSIONS: The AI-based noise reduction could improve the IQ of aorta CTA with low kV and reduced CM, which achieved the potential of radiation dose and contrast media reduction compared with conventional aorta CTA protocol.

Diagnosis of coronary artery disease in patients with atrial fibrillation using low tube voltage coronary CT angiography with isotonic low-concentration contrast agent.

This prospective study evaluated the image quality and accuracy of coronary computed tomography angiography (CCTA) for diagnosing coronary artery disease (CAD) in patients with atrial fibrillation (AF), in which CCTA used adaptive iterative dose reduction (AIDR) with a low tube voltage and low concentration of isotonic contrast agent. Sixty-eight consecutive patients with AF and suspected CAD were equally and randomly apportioned to two groups and underwent CCTA. In the experimental group, the contrast agent was iodixanol (270 mg I/mL), patients were scanned with 100 kV, and reconstruction was by AIDR. In the conventional scanning (control) group, the contrast agent was iopromide (370 mg I/mL), patients were scanned with 120 kV, and reconstruction was by filtered back projection. The image quality, effective radiation dose (E), and total iodine intake of the groups were compared. Thirty-nine patients with coronary artery stenosis later were given invasive coronary angiography (ICA). The groups were similar with regard to mean CT value, noise, and signal-to-noise and contrast-to-noise ratios. The figure of merit of the experimental group was significantly higher than that of the control group, while the E and total iodine were significantly lower. Using ICA as the diagnostic reference, the groups shared similar sensitivity, specificity, and false positive and false negative rates for diagnosing coronary artery stenosis. For determining CAD in patients with AF, CCTA with isotonic low-concentration contrast agent and low-voltage scanning is a feasible alternative that improves accuracy and reduces radiation dose and iodine intake.

Intrathecal Use of Gadobutrol for Glymphatic MR Imaging: Prospective Safety Study of 100 Patients.

BACKGROUND AND PURPOSE: Intrathecal contrast-enhanced glymphatic MR imaging has shown promise in assessing glymphatic function in patients with dementia. The purpose of this study was to determine the safety profile and feasibility of this new MR imaging technique. MATERIALS AND METHODS: A prospective safety and feasibility study was performed in 100 consecutive patients (58 women and 42 men, 51 ± 19 years of age) undergoing glymphatic MR imaging from September 2015 to August 2018. Short- and long-term serious and nonserious adverse events were registered clinically and by interview after intrathecal administration of 0.5 mL of gadobutrol (1.0 mmol/mL) along with 3 mL of iodixanol (270 mg I/mL). Adverse events are presented as numbers and percentages. RESULTS: One serious adverse event (anaphylaxis) occurred in a patient with known allergy to iodine-containing contrast agents (1%). The main nonserious adverse events during the first 1-3 days after contrast injection included severe headache (28%) and severe nausea (34%), though the frequency depended heavily on the diagnosis. After 4 weeks, adverse events had resolved. CONCLUSIONS: Intrathecal administration of gadobutrol in conjunction with iodixanol for glymphatic MR imaging is safe and feasible. We cannot conclude whether short-duration symptoms such as headache and nausea were caused by gadobutrol, iodixanol, the lumbar puncture, or the diagnosis. The safety profile closely resembles that of iodixanol alone.

An augmented patient-specific approach to administration of contrast agent for CT renal angiography.

PURPOSE: This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. MATERIALS AND METHODS: 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). RESULTS: Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p<0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p<0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. CONCLUSION: Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.

Ethiodized poppyseed oil versus ioversol for image quality and adverse events in hysterosalpingography: a prospective cohort study.

BACKGROUND: This study aimed to investigate the image quality and adverse events (AEs) of ethiodized poppyseed oil (EPO) compared with ioversol as contrast agents in hysterosalpingography (HSG). METHODS: Two hundred twenty-eight patients underwent HSG were consecutively recruited in this prospective cohort study, and were accordingly divided into EPO group (N = 165) and ioversol group (N = 63). The quality of image was assessed according to the European Guidelines on quality criteria for diagnostic radiographic images. AEs during, within 2 h and at 1-month post-HSG were recorded. RESULTS: EPO displayed elevated image quality compared with ioversol including the total image quality score (P < 0.001), the cervical canal display score (P < 0.001), shape and outline of uterus score (P < 0.01), cervical mucosa or folds score (P < 0.001), oviduct isthmus score (P < 0.001), ampulla and fimbriae of oviduct score (P < 0.001) and celiac diffuse image score (P < 0.001). Multivariate linear regression displayed that EPO (P < 0.001) was an independent predictive factor for increased total image quality score. AEs were similar between EPO group and ioversol group during and within 2 h post-HSG (all P > 0.05). However, at 1-month post-HSG, the number of patients had unchanged and faded menstrual blood color decreased but the proportion of patients with deepened menstrual color increased in EPO group compared with ioversol group (P = 0.007). In addition, the number of patients had iodine residue in uterine cavity was elevated in EPO group compared with ioversol group (P < 0.001). CONCLUSION: EPO is more efficient in image quality and equally tolerant compared to ioversol as contrast agents in HSG.

Application of Blood Oxygenation Level-Dependent Magnetic Resonance Imaging and Intravoxel Incoherent Motion to Assess Bilateral Renal Pathophysiological Processes Induced by Iodixanol Renal Artery First-Pass in Rabbit Model.

BACKGROUND: Noninvasive blood oxygen level-dependent imaging and intravoxel incoherent motion sequences were used to assess bilateral renal oxygenation, hemodynamics, and proton diffusion in iodixanol renal artery first-pass in rabbit model. METHODS: Forty-two rabbits were divided into 2 groups. Saline and iodixanol (1 g iodine/kg, left renal artery) were administered. Magnetic resonance imaging scans were acquired longitudinally at 24 hours prior to and 1, 24, 48, and 72 hours after administration to assess apparent diffusion coefficient, pure molecular diffusion (D), perfusion-related diffusion (D*), volume fraction (f), and relative spin-spin relaxation rate (R2*) values, respectively. The experiment evaluated serum creatinine, histological, and hypoxia-inducible factor 1α immunoexpression. RESULTS: During 1 to 48 hours, the values of D, f, and D* significantly decreased (P < 0.05), but R2* values significantly increased (P < 0.05) in cortex, outer medulla, and inner medulla after administration of iodixanol through left renal artery, which showed in the 72 hours. The change of the left kidney is noteworthy. Significant negative correlations were observed between apparent diffusion coefficient, D, f, and R2* in cortex, outer medulla, and inner medulla (all P < 0.001, r = -0.635-0.697). CONCLUSIONS: The first-pass effect of the contrast agent significantly reduces ipsilateral renal perfusion and renal oxygenation, and noninvasive monitoring can be performed by using blood oxygen level-dependent magnetic resonance imaging and intravoxel incoherent motion.

Evaluation of iodine contrast-induced acute kidney injury via different injection routes using BOLD-MRI.

OBJECTIVES: The aim of this study was to evaluate and compare the severity of acute kidney injury (AKI) induced by iodine contrast agent injection via the renal artery, ear vein, and femoral artery in a rabbit model. METHODS: Blood oxygenation level-dependent (BOLD) magnetic resonance (MR) scans were performed at 24 h prior to contrast injection and 1, 24, 48, and 72 h after injection. Iodixanol injection dose was 1.0, 1.5, 2.0, and 2.5 g iodine/kg, respectively. Hypoxia-inducible factor-1α (HIF-1α) expression was determined, and the BOLD-MRI parameter R2* was used to express tissue oxygenation. Increases in R2* levels reflect reductions in tissue oxygenation. Analyses including R2* value, dose response, histology, and HIF-1α were conducted. RESULT: Injection of 1.0 g iodine/kg into the left renal artery resulted in significant increases in renal R2* values after 24 h. This was equivalent to the change of R2* after 2.0 g iodine/kg femoral artery injection. Renal injury scores and HIF-1α expression scores were significantly increased at 24 h. The R2* values exhibited a positive linear correlation with histological injury scores. The maximum effects occurred 24 h after iodixanol injection and returned to baseline levels within 72 h. CONCLUSIONS: The renal injury induced by 1.0 g iodine/kg iodixanol through renal artery injection was more significant than that caused by the same dose of femoral artery and auricular vein injection, while similar to that caused by 2.0 g iodine/kg femoral artery injection.