Iohexol Group Research Articles

Comparison of Diatrizoate and Iohexol for Patient Acceptance and Fecal-Tagging Performance in Noncathartic CT Colonography.

The aim of this study was to compare diatrizoate and iohexol regarding patient acceptance and fecal-tagging performance in noncathartic computed tomography colonography. This study enrolled 284 volunteers with fecal tagging by either diatrizoate or iohexol at an iodine concentration of 13.33 mg/mL and an iodine load of 24 g. Patient acceptance was rated on a 4-point scale of gastrointestinal discomfort. Two gastrointestinal radiologists jointly analyzed image quality, fecal-tagging density and homogeneity, and residual contrast agent in the small intestine. The results were compared by the generalized estimating equation method. Patient acceptance was comparable between the 2 groups (3.95 ± 0.22 vs 3.96 ± 0.20, P = 0.777). The diatrizoate group had less residual fluid and stool than the iohexol group ( P = 0.019, P = 0.004, respectively). There was no significant difference in colorectal distention, residual fluid, and stool tagging quality between the 2 groups (all P 's > 0.05). The mean 2-dimensional image quality score was 4.59 ± 0.68 with diatrizoate and 3.60 ± 1.14 with iohexol ( P < 0.001). The attenuation of tagged feces was 581 ± 66 HU with diatrizoate and 1038 ± 117 HU with iohexol ( P < 0.001). Residual contrast agent in the small intestine was assessed at 55.3% and 62.3% for the diatrizoate group and iohexol group, respectively ( P = 0.003). Compared with iohexol, diatrizoate had better image quality, proper fecal-tagging density, and more homogeneous tagging along with comparable excellent patient acceptance, and might be more suitable for fecal tagging in noncathartic computed tomography colonography.

Role of TLR4/MyD88/NF-κB signaling in the contrast-induced injury of renal tubular epithelial cells.

The aim of the present study was to explore the role of toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor (NF)-κB signaling in the contrast-induced injury of renal tubular epithelial cells, and to investigate the potential mechanisms. HK-2 cells cultured in vitro were randomly divided into six groups as follows: i) The blank group; ii) the iohexol group; iii) the NF-κB RNAi group (NF-κB siRNA + iohexol); iv) the TLR4 RNAi group (TLR4 siRNA + iohexol); v) the NF-κB blocker group (PDTC + iohexol); and vi) the TLR4 blocker group (CLI-095 + iohexol). The expression of the TLR4/MyD88/NF-κB signaling pathway proteins was detected by reverse transcription-quantitative (RT-q)PCR and western blot analysis, and the cellular proliferation rate was determined using the Cell Counting Kit-8 assay. The mRNA expression levels of the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were also detected using RT-qPCR, and apoptosis was assessed by flow cytometry and western blotting to detect apoptosis-associated proteins (caspase-3, caspase-9 and cleaved caspase-9). Compared with the blank group, the apoptotic rates and the expression levels of TLR4, MyD88, NF-κB, caspase-3, cleaved caspase-9, TNF-α, IL-1β and IL-6 were upregulated in the iohexol group (P<0.001). However, when TLR4 or NF-κB were blocked or silenced, these effects were reversed (P<0.001). Collectively, the results of the present study indicated that TLR4/MyD88/NF-κB signaling is involved in the contrast-induced injury of renal tubular epithelial cells by inducing inflammation and apoptosis.

Assessment of Rac1 and β-PAK Expressions in a Mouse Model for Contrast-Induced Nephropathy

Purpose: Radiocontrast-induced nephropathy is an important clinical problem in high-risk patients. The mechanism of cytotoxic effect of radiocontrast media on kidneys is still not fully clarified. Rac1/β-PAK pathway has been shown to play a role in other nephropathies such as diabetic nephropathy. In this study, it was aimed to determine whether Rac1/β-PAK signalling pathway has any role in the development of contrast-induced nephropathy CIN . Methods: Adult male Balb/C mice were used. A single dose of iohexol was given intraperitoneally. Thirty-two mice were divided into 5 groups including control Group1, n=4 , pretreatment Group 2, n=7 , low dose 2 g iodine/kg iohexol Group 3, n=7 , medium dose 2.5 g iodine/kg iohexol Group 4, n=7 and high dose 3 g iodine/kg iohexol Group 5, n=7 . The animals were sacrificed 24 hours after iohexol administration. Nephropathy were evaluated by histological and biochemical analysis methods. Expressions of Rac1 and β-PAK were evaluated by immunohistochemical method. Apoptosis was assessed by TUNEL method. Results: It was found that severity of nephropathy, apoptosis and β-PAK expressions significantly increased as iohexol dosage increased. Although Rac1 expression was higher in the iohexol group in comparison to the control and pretreatment groups, its increase did not show a dose-dependent manner. There was no significant difference among the groups in terms of serum creatinine. Serum cystatin C were increased in all groups compared to the control group, but significant increase was observed only in the pretreatment group. Conclusions: Our findings suggest that the Rac1/β-PAK signal transduction pathway may have a role in the contrast-induced nephropathy model.

Astaxanthin attenuates contrast-induced acute kidney injury through silent mating-type information regulation 2 homolog-1/peroxisome proliferator-activated receptor γ co-activator–α/NRF1 signaling pathway

Objectives: In this study, we established a model of contrast-induced acute kidney injury with iohexol. This model was used to investigate whether astaxanthin (AST) attenuates oxidative stress and apoptosis by activating silent mating-type information regulation 2 homolog-1 (SIRT1) signaling pathway in rat renal tubular epithelial cells (NRK-52E). Materials and Methods: NRK-52E cells were randomly divided into six groups: control group (CON group), vehicle (dimethyl sulfoxide group, iohexol group (I group), AST pretreatment group (AST + I group), AST plus nicotinamide (NA) co-pretreatment group (AST + NA + I group), and NA treatment group (NA + I group). The cellular activity was measured by cell counting kit-8. We estimated the levels of malonaldehyde (MDA) by the thiobarbituric acid method, and the level of intracellular reactive oxygen species (ROS) was measured by flow cytometry. Western blot analysis was conducted to detect the protein levels of SIRT1, peroxisome proliferator-activated receptor γ co-activator–α (PGC-1α), and NRF1. Results: Compared with the CON group, the I group showed suppressed cellular activity; increased levels of MDA and ROS; and decreased levels of SIRT1, PGC-1α, and NRF1 protein. Compared with the I group, AST + I pretreated group showed high cellular activity; low levels of MDA and ROS; and increased levels of SIRT1, PGC-1α, and NRF1 protein. SIRT1 inhibitor NA reversed the protective effect of AST. Compared with the AST + NA + I group, NA + I group showed low cellular activity; high levels of MDA and ROS; and low levels of SIRT1, PGC-1α, and NRF1 protein, which further confirmed the protective effect of AST. Conclusion: AST alleviated iohexol-induced NRK-52E cell injury by decreasing the formation of MDA and ROS and upregulating the SIRT1/PGC-1α/NRF1 signaling pathway.

Resveratrol Protects Against Post-Contrast Acute Kidney Injury in Rabbits With Diabetic Nephropathy.

Resveratrol (Res) is a multi-functional polyphenol compound that has protective functions in acute kidney diseases. Here, we examined whether the resveratrol could ameliorate post-contrast acute kidney injury (PC–AKI) following diabetic nephropathy (DN), and explored any underlying mechanism(s) in vivo and in vitro. Twenty-four rabbits with DN were randomly divided into four groups: control (Cont), resveratrol (Res), iohexol (PC–AKI), and resveratrol plus iohexol (Res+PC–AKI) groups. Functional magnetic resonance imaging, renal histology, blood and urinary biomarkers, silent information regulator l (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), hypoxia-inducible transcription factor-1α (HIF-1α), and apoptosis-associated protein expression were assessed ex vivo. For in vitro experiments, renal tubular epithelial (HK-2) cells subjected to high glucose conditions were treated with resveratrol, Ex527, an SIRT1 inhibitor, or 2-methoxyestradiol (2-MeOE2), HIF-1α inhibitor, before treatment with iohexol. With regard to the rabbit model of acute renal injury in DN, compared to the PC–AKI group, the Res+PC–AKI group showed decreased levels of cystatin C and urinary neutrophil gelatinase-associated lipocalin, increased pure molecular diffusion (D) and the fraction of water flowing in capillaries (f), a decreased apparent relaxation rate (R2*), renal injury score and apoptosis rate, increased protein expression levels of SIRT1 and PGC-1α, and decreased levels of HIF-1α and apoptosis-associated protein. In addition, iohexol decreased HK-2 cell survival and increased the cell apoptosis rate; results were reversed after treating cells with resveratrol. Resveratrol reduced renal hypoxia, mitochondrial dysfunction and renal tubular cell apoptosis by activating SIRT1–PGC–1α–HIF-1α signaling pathways in PC–AKI with DN.

Astaxanthin attenuates contrast agent-induced acute kidney injury in vitro and in vivo via the regulation of SIRT1/FOXO3a expression.

The study was processed to investigate the effect of astaxanthin (AST; 3,3-dihydroxybeta, beta-carotene-4,4-dione) on the acute kidney injury induced by iohexol and the relationship with SIRT1/FOXO3a signal pathway. Thirty male Sprague Dawley rats were randomly divided into five groups as follows: control group (CON; olive oil only), contrast media group, astaxanthin control group (100mg/kg), low astaxanthin dose group (LAG, 50mg/kg) and high astaxanthin dose group (HAG, 100mg/kg). As followed, serum creatinine (SCr), blood urea nitrogen (BUN), the oxidative stress markers and apoptosis-related proteins were detected. Human proximal tubular epithelial cells (HK-2) were cultured in DMEM/F12 medium in vitro and then randomly divided into appropriate experimental groups: normal group (N), dimethyl sulfoxide (DMSO), iohexol group (I), iohexol+(1.0, 10.0μmol/L) astaxanthin group (I+LAST; I+HAST), iohexol+SIRT1 inhibitors (nicotinamide) group (NA) and iohexol+si-RNA FOXO3a group (si-RNA FOXO3a); when cultured for 24h, cell proliferation ability was tested by cell counting kit (CCK-8), reactive oxygen species (ROS) were detected by flow cytometry and the expression of SIRT1 and FOXO3a were observed using western blot. At the end of the experiment, the levels of SCr, BUN and malondialdehyde (MDA) were all increased in the CM group. The LAG and HAG reduce superoxide anion (SOD) activity, catalase (CAT) activity, glutathione peroxidase (GPx) activity and glutathione (GSH) content, as well as SCr and BUN level. Moreover, apoptosis-associated proteins, caspase 3 p17, bax and bcl-2 were upregulated. In HK-2 cells, after adding iohexol, proliferation and intracellular ROS levels were significantly increased. Using astaxanthin in advance after the intervention, the result is opposite. SIRTl inhibitors NA can reduce the expression of SIRTl and decrease the expression of FOXO3a protein. Si-RNA FOXO3a reduces the expression of FOXO3a but had no significant effect on the expression of SIRT1. Our study demonstrates that the intervention of astaxanthin could attenuate the oxidative stress and apoptosis in contrast-induced acute kidney injury (CI-AKI), and the SIRT1/FOXO3a pathway participates in the contrast-induced apoptosis of HK-2 cells. Finally, astaxanthin reduces CI-AKI by suppression of apoptosis, which may be through inhibition of SIRT1/FOXO3a pathways.

Study on the Correlation between Barium Radiography and Pulmonary Infection rate in the Evaluation of Swallowing Function

OBJECTIVES:To compare the results respectively obtained from the utilization of 60% barium sulfate suspension and Iohexol as contrast agents for videofluoroscopic swallowing studies and the relationship between the clinical application of the two kinds of contrast agents and the incidence of pneumonia.METHODS:Sixty cases of stroke patients with dysphagia were selected in rehabilitation department of our hospital, and the gender, age, position of the disease, and stroke nature between groups had no significant difference. Among which, 30 patients who were administered 350 mgI/ml Iohexol, and the other 30 patients with 60% barium sulfate suspension as contrast agent. We performed videofluoroscopic swallowing studies with barium 60% versus Iohexol within 1 week after admission and 2 weeks after admission.RESULTS:After 2 weeks in hospital, the aspiration pneumonia incidence of two groups was statistically significant (p<0.05), the pneumonia incidence of Iohexol group was lower than barium sulfate group which might have a impossble relevance with barium aspiration.CONCLUSIONS:During the videofluoroscopic swallowing study of dysphagia after stroke, barium sulfate can enhance the pneumonia incidence, and Iohexol can be widely applied in videofluoroscopic swallowing study.

Comparison of the nephrotoxic effects of iodixanol versus iohexol in patients with chronic heart failure undergoing coronary angiography or angioplasty.

The aim of this clinical trial is to compare iodixanol with iohexol for the incidence of contrast-induced nephropathy in patients with chronic heart failure with reduced ejection fraction who are currently undergoing coronary angiography or angioplasty. The clinical trial included 220 consecutive patients with chronic heart failure with reduced ejection fraction undergoing coronary angiography or angioplasty. Study participants were administered either iodixanol (n = 110) or iohexol (n = 110). The primary study endpoint was the incidence of contrast-induced nephropathy within 72 h after the procedure. The secondary endpoints were to determine the peak increase in serum creatinine levels and Cystatin C, and the peak decrease in estimated glomerular filtration rate at 72 h post-contrast medium. Baseline demographic and clinical characteristics of the patients were similar between the two groups. Our study showed that the overall incidence of contrast induced nephropathy in patients with chronic heart failure was 20.9%. The incidence of contrast induced nephropathy was significantly lower in iodixanol group than in iohexol group (29.1% vs 12.7%, P = 0.041). The peak increase in serum creatinine levels and the peak decrease in estimated glomerular filtration rate after the procedure were statistically significant between the two groups. Moreover, there was statistically significance in the peak increase of Cystatin C levels after the procedure. In patients with chronic heart failure with reduced ejection fraction who are currently undergoing coronary angiography with or without percutaneous coronary intervention, the iso-osmolar contrast iodixanol was associated with a lower incidence of contrast induced nephropathy than low-osmolar contrast iohexol.

Safety enhancement in adult body computed tomography scanning: comparison of iodixanol versus iohexol.

BackgroundThe aim of this study was to compare the safety and intra-individual contrast enhancement of low-osmolar monomeric iohexol and the iso-osmolar dimeric iodixanol in body computed tomography (CT) scanning.MethodsIn this single center, double-blind, prospective study, a total of 2000 consecutive patients undergoing adult body CT scanning were prospectively enrolled, with 1000 patients assigned to iodixanol and 1000 patients assigned to iohexol. In both groups, the contrast medium was injected at the rate of 3.5 ml/s. Subjective assessment of image quality for each image was determined using a 3-grading scale by three reviewers. Patients were monitored with questioning and vital signs before injection, immediately after injection, and at 24 and 48 h. Extensive laboratory evaluation also was performed.ResultsLaboratory results showed no significant difference across groups. There were also no detectable differences in image quality between the two contrast groups in this study. The total adverse reactions occurred in less than 1 % of individuals receiving iodixanol comparing to 2.5 % in iohexol group (P < 0.05). Among them, only 0.7 % patients injecting iodixanol suffered immediate events, comparing to 2 % patients in iohexol group. In all, 0.2 % patients with iodixanol and 0.5 % with iohexol had late allergic reaction. Further, No deaths occurred in any of the two groups.ConclusionsThe iso-osmolar iodixanol provides image quality compared with that of iohexol, with lower incidence of adverse events.

Correlation studies of barium on pulmonary infection under the assessment of VFSS.

Stroke is a common clinical disease resulting in somatic dyskinesia as well as different degrees of dysphagia. The aim of the study was to assess the results obtained from the utilization of 60% barium sulfate suspension and iohexol as contrast agents in video fluoroscopic swallowing studies (VFSS), and compare the association between the clinical application of the two contrast agents and the incidence of pneumonia. A total of 60 cases of in-patients with dysphagia caused by stroke were selected and divided into two groups based on the diagnostic standard. No obvious differences were evident between the groups with regard to gender, age, position of stroke and the nature of stroke. The patients were divided into an iohexol group of 30 patients administered with 350 mgI/ml iohexol as a contrast agent, and a barium sulfate group of 30 patients administered with 60% barium sulfate suspension as a contrast agent. A VFSS evaluation was implemented before and after 3 weeks of treatment, respectively, and the pharynx transit time was compared between the two groups of contrast agents according to the position of stroke. By using case-control studies, the incidence of pneumonia between the two groups of patients within 2 weeks after hospitalization was analyzed and the association between the complication probability with different contrast agents was analyzed. After 2 weeks in hospital, the incidence of aspiration pneumonia of the two groups was statistically significant (P<0.05). The incidence of pneumonia of the iohexol group was markedly lower than that of the barium sulfate group, which may be important for barium aspiration. In conclusion, in the VFSS of dysphagia after stroke and barium sulfate increased the incidence of pneumonia, and that iohexol was widely used in video fluoroscopy.

GW26-e1009 Protective effect of astaxanthin on contrast-induced acute kidney injury in experimental rats

To explore the protective effect and mechanism of astaxanthin(AST) on the acute kidney injury induced by iohexol in rats. Thirty rats were randomly divided into five groups: control group ( CON ), iohexol group ( CM ), astaxanthin group( AST, 100mg/kg ), low astaxanthin dose group ( LAST+CM, 50mg/

Risk of Nephropathy After Consumption of Nonionic Contrast Media by Children Undergoing Cardiac Angiography: A Prospective Study

Despite increasing reports on nonionic contrast media-induced nephropathy (CIN) in hospitalized adult patients during cardiac procedures, the studies in pediatrics are limited, with even less focus on possible predisposing factors and preventive measures for patients undergoing cardiac angiography. This prospective study determined the incidence of CIN for two nonionic contrast media (CM), iopromide and iohexol, among 80 patients younger than 18 years and compared the rates for this complication in relation to the type and dosage of CM and the presence of cyanosis. The 80 patients in the study consecutively received either iopromide (group A, n = 40) or iohexol (group B, n = 40). Serum sodium (Na), potassium (K), and creatinine (Cr) were measured 24 h before angiography as baseline values, then measured again at 12-, 24-, and 48-h intervals after CM use. Urine samples for Na and Cr also were checked at the same intervals. Risk of renal failure, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage renal damage (RIFLE criteria) were used to define CIN and its incidence in the study population. Accordingly, among the 15 CIN patients (18.75%), 7.5% of the patients in group A had increased risk and 3.75% had renal injury, whereas 5% of group B had increased risk and 2.5% had renal injury. Whereas 33.3% of the patients with CIN were among those who received the proper dosage of CM, the percentage increased to 66.6% among those who received larger doses, with a significant difference in the incidence of CIN related to the different dosages of CM (p = 0.014). Among the 15 patients with CIN, 6 had cyanotic congenital heart diseases, but the incidence did not differ significantly from that for the noncyanotic patients (p = 0.243). Although clinically silent, CIN is not rare in pediatrics. The incidence depends on dosage but not on the type of consumed nonionic CM, nor on the presence of cyanosis, and although CIN usually is reversible, more concern is needed for the prevention of such a complication in children.

Comparison of Iodixanol and Iohexol in Patients Undergoing Intravenous Pyelography: A Prospective Controlled Study

Background. Nephropathy associated with contrast medium exposure is a well-known complication of IVP. However, it is uncertain whether iso-osmolar non-iodinated contrast medium (iodixanol) is less nephrotoxic than low-osmolar contrast medium (iohexol). Materials and Methods. In this single-center, double-blind, prospective study, 50 patients undergoing IVP were randomized into two groups receiving different contrast medium: iodixanol and iohexol. Patients in high risk for contrast nephropathy were included, 28 with renal insufficiency and 19 with diabetes mellitus. We compared the nephrotoxic effect (contrast nephropathy), complement and cytokines profile between the iodixanol and iohexol groups. The mean volume of contrast medium in each IVP procedure was 0.8 mL/kg. Results. The incidence of contrast nephropathy was 4 percent among all patients (one iodixanol and one iohexol). We found no significant differences in contrast nephropathy and allergic reactions between the two groups. There was no significant difference in cytokine profiles in both groups (p > 0.05).The incidence of allergic reaction was 16 percent among all patients. Twelve percent (3/25) had late reaction after iohexol exposure compared to four percent (2/25) with iodixanol (p = 1.0). One patient had severe skin rash due to late adverse reaction after iodixanol. No mortality was found. Conclusions. New iodixanol and iohexol contrast medium for routine IVP examination are safe and have low nephrotoxicity profile, especially in elderly or high-risk patients. Iodixanol contrast medium has an increased risk to induce severe late adverse reaction compared to iohexol. Allergic reaction may be the main adverse effect after contrast medium infusion.

Interference of iohexol with radioiodine thyroid uptake in the hyperthyroid cat.

Absorbed thyroid dose and effective half-life were determined in 46 hyperthyroid cats after treatment with a low dose (mean 111MBq) of radioiodine intravenously. Thirteen of these cats had received iohexol for glomerular filtration rate (GFR) measurement within 24h before treatment with radioiodine in view of another ongoing study at our institution. Pre-therapy values were obtained for total thyroxine (TT(4)) and for the thyroid to salivary gland ratio with sodium pertechnetate gamma-camera imaging. All cats underwent post-therapy scans at 24, 48 and 120 h for evaluation of radioactive iodine uptake (RAIU) and the effective half-life of radioiodine. The absorbed dose was calculated from the cumulative activity with Olinda software. Both groups were comparable in age, TT(4) and the ratio of thyroid activity to salivary gland activity. Statistical analysis revealed a significant decreased absorbed dose in the thyroid in the iohexol group. This decreased uptake was not accompanied by an decreased effective half-life of the radioiodine. The variation of inter-individual RAIU decreased in this group and more homogenous absorbed doses were obtained. No significant difference in outcome could be demonstrated. However, a tendency towards a higher number of residual hyperthyroidism in the iohexol group was noted (15 versus 6% in control group). This study demonstrates that iohexol interferes with the uptake of radioiodine in the hyperthyroid cat but does not provoke increased turnover. In this study, albeit including a small number of cats, outcome did not seem to be significantly affected.

Contrast Enhancement in Cardiac MDCT: Comparison of Iodixanol 320 Versus Iohexol 350

The objective of our study was to evaluate whether iodixanol 320 mg I/mL (iodixanol 320), with the highest iodine concentration of dimeric nonionic contrast agents on the market, results in decreased vascular or myocardial enhancement compared with iohexol 350 mg I/mL (iohexol 350). During a 4-month period, 72 patients referred for cardiac MDCT were consecutively enrolled and randomized into two groups: iohexol 350 and iodixanol 320. The injection and scanning protocols were the same for both groups. Enhancement of the right heart, left heart, coronary arteries, and left ventricular (LV) myocardium in both the arterial and delayed phases was compared using two-tailed independent Student's t test. Enhancement in the right heart, left heart, coronary arteries, and LV myocardium in the arterial phase showed no statistical difference (p > 0.05) between the two groups, although the iohexol group showed slightly higher enhancement (average, 11.2 H) in all of the areas. Surprisingly, in the delayed phase, the iodixanol group displayed significantly higher (7.7 H) persistent enhancement (p < 0.05) in the LV myocardium. Iodixanol 320 can provide vascular enhancement in cardiac MDCT that is similar to iohexol 350. In the delayed phase, iodixanol 320 shows significantly higher delayed enhancement (7.7 H) in the LV myocardium than iohexol 350.

Nephrotoxic effects in high-risk patients undergoing angiography

BACKGROUND: The use of iodinated contrast medium can result in nephropathy. Whether iso-osmolar contrast medium is less nephrotoxic than low-osmolar contrast medium in high-risk patients is uncertain. METHODS: We conducted a randomized, double-blind, prospective, multicenter study comparing the nephrotoxic effects of an iso-osmolar, dimeric, nonionic contrast medium, iodixanol, with those of a low-osmolar, nonionic, monomeric contrast medium, iohexol. The study involved 129 patients with diabetes with serum creatinine concentrations of 1.5 to 3.5 mg per deciliter who underwent coronary or aortofemoral angiography. The primary end point was the peak increase from base line in the creatinine concentration during the three days after angiography. Other end points were an increase in the creatinine concentration of 0.5 mg per deciliter or more, an increase of 1.0 mg per deciliter or more, and a change in the creatinine concentration from day 0 to day 7. RESULTS: The creatinine concentration increased significantly less in patients who received iodixanol. From day 0 to day 3, the mean peak increase in creatinine was 0.13 mg per deciliter in the iodixanol group and 0.55 mg per deciliter in the iohexol group (P=0.001, the increase with iodixanol minus the increase with iohexol, -0.42 mg per deciliter [95 percent confidence interval, -0.73 to -0.22]). Two of the 64 patients in the iodixanol group (3 percent) had an increase in the creatinine concentration of 0.5 mg per deciliter or more, as compared with 17 of the 65 patients in the iohexol group (26 percent) (P=0.002, odds ratio for such an increase in the iodixanol group, 0.09 [95 percent confidence interval, 0.02 to 0.41]). No patient receiving iodixanol had an increase of 1.0 mg per deciliter or more, but 10 patients in the iohexol group (15 percent) did. The mean change in the creatinine concentration from day 0 to day 7 was 0.07 mg per deciliter in the iodixanol group and 0.24 mg per deciliter in the iohexol group (P=0.003, value in the iodixanol group minus the value in the iohexol group, -0.17 mg per deciliter [95 percent confidence interval, -0.34 to -0.07]). CONCLUSIONS: Nephropathy induced by contrast medium may be less likely to develop in high-risk patients when iodixanol is used rather than a low-osmolar, nonionic contrast medium.

Iodixanol in paediatric gastrointestinal imaging: safety and efficacy comparison with iohexol

Iodixanol (Visipaque) is a dimeric, non-ionic iodinated contrast medium that is isotonic with blood at all clinically relevant concentrations. Iodixanol was compared in a randomized, double blind, parallel group, phase III multicentre trial with a monomeric, non-ionic contrast medium, iohexol (Omnipaque), at two concentrations assessing safety, tolerability and radiographic efficacy during contrast enhanced gastrointestinal radiography examinations of children. 154 children entered the trial; 152 formed the safety population and 147 the efficacy population. All examinations were performed following standard departmental practice. Children were assigned into either a high or low concentration group (iodixanol, 150 mgI ml(-1) and 320 mgI ml(-1) vs iohexol, 140 mgI ml(-1) and 300 mgI ml(-1)). The primary outcome measure for efficacy was the overall quality of visualization, which was assessed using a 100 mm visual analogue scale (VAS). The secondary efficacy variables assessed were quality of contrast opacification, mucosal coating and overall quality of diagnostic information. Safety evaluation involved patient follow-up for at least 48 h. Taste acceptance was also assessed. There was no statistically significant difference between the two contrast media with regard to the primary and secondary efficacy variables assessed, although higher ratings were observed for iodixanol. The 100 mm VAS score overall was 86 mm for iodixanol and 82 mm for iohexol (95% confidence interval -2.56, 10.42). The frequency of adverse events was lower for patients receiving iodixanol. Adverse events, mainly diarrhoea, occurred in 12 patients (16.2%) in the iodixanol group and 28 patients (35.9%) in the iohexol group. This reached statistical significance (p=0.006). Overall, iodixanol is well suited for examinations of the gastrointestinal tract, giving good efficacy results and fewer adverse events than iohexol.

Experiences with iohexol and iodixanol during cardioangiography in an unselected patient population

Aim: To compare the frequency of adverse events after cardioangiography with iohexol and iodixanol in an unselected patient population with special regard to previously defined “risk patients”: age≥65 years, severe coronary artery disease, unstable angina pectoris and left ventricular dysfunction. Methods: A total of 1020 patients referred to cardioangiography were included in this open, prospective cross-sectional study, comparing iodixanol (320 mgI/ml) and iohexol (350 mgI/ml). Adverse events were recorded and the patients answered a questionnaire. Results: Cardiac adverse events (CAE) i.e., angina pectoris, arrhythmia and dyspnea within 24 h of examination were reported by 9% of patients receiving iohexol and by 7% receiving iodixanol. Two cases of ventricular fibrillation occurred, both after iohexol. The proportion of CAE was 11% for patients≥65 years receiving iohexol and 7% in younger patients. For patients receiving iodixanol the proportion was 7%, in both age groups. Patients with severe coronary disease had more CAE than less ill patients in both CM groups. The proportion of unstable patients with CAE was 18% in the iohexol group and 12% in the iodixanol group. Left ventricular dysfunction was not related to CAE. Conclusions: Iodixanol could be advantageous in patients with unstable angina.

Percutaneous Coronary Angioscopic Comparison of Thrombus Formation During Percutaneous Coronary Angioplasty With Ionic and Nonionic Low Osmolality Contrast Media in Unstable Angina

Patients with unstable coronary syndromes are more likely to have a lesion containing thrombus and have a higher procedural complication and restenosis rate. The aim of this study was to evaluate the effect of an ionic (ioxaglate) and a nonionic (iohexol) low osmolality contrast media on thrombus generation using percutaneous intracoronary angioscopy in patients with unstable angina undergoing percutaneous transluminal coronary angioplasty (PTCA). Thirty patients with unstable angina pectoris randomized to either ioxaglate or iohexol (15 patients in each group), underwent percutaneous intracoronary angioscopy before and after PTCA and 15 minutes after PTCA. Angioscopically visible thrombus was defined using the Ermenonville classification and the lesion divided into 3 zones—proximal, mid, and distal. Angiographic filling defects were seen in 3 patients before PTCA, and in 10 after PTCA. Angioscopically visible thrombus was seen in 10 patients before PTCA in the ioxaglate group and 8 in the iohexol group. After PTCA 5 patients (33.3%) in the ioxaglate and 11 (73.6%) in the iohexol group developed new thrombus, p = 0.028. Total thrombi before PTCA were 16 versus 13, after PTCA 25 versus 27, and at 15 minutes after PTCA 23 versus 25, ioxaglate versus iohexol respectively, p = NS. There was no correlation between type or extent of intimal dissection and angioscopically visible new thrombus formation. Angiography underestimated the incidence of intracoronary thrombus before and after PTCA. Nonionic low osmolality contrast medium was associated with significantly more patients developing angioscopically visible new thrombus. This has clinical implications in the choice of contrast medium used in PTCA, particularly in the setting of unstable angina.

Iopentol (Imagopaque® 350) compared with iohexol (Omnipaque® 350) in pediatric cardioangiography A clinical trial assessing adverse events, ECG, blood pressure and diagnostic information

A non-ionic, monomeric, low-osmolar contrast medium, iopentol (Imagopaque, Nycomed Imaging AS, Oslo, Norway) has been compared with iohexol (Omnipaque, Nycomed Imaging AS, Oslo, Norway) in a double-blind, randomized, parallel-group trial in children. The aims of the study were to compare the safety and radiographic efficacy of iopentol 350 mg I/ml versus those of iohexol 350 mg I/ ml in pediatric cardioangiography. Seventy-three children, of whom 35 received iopentol and 38 iohexol, were included in the evaluation. The quality of overall diagnostic information was excellent or adequate in all patients. There were no statistically significant differences between numbers of patients reporting adverse events nor number of patients reporting discomfort in the two groups. Three patients in the iopentol group and two patients in the iohexol group reported adverse events. Heat sensation was reported by 4 patients in the iopentol group and 5 patients in the iohexol group. Following injection of contrast medium, there were no differences between the groups regarding ECG, heart rate and systolic blood pressure at the site of injection. Iopentol was demonstrated to be as effective, safe and well tolerated as iohexol in pediatric cardioangiography.