An open label, prospective, multicenter, non-interventional study of iodixanol 270 mg I/mL for use in individuals undergoing computed tomography angiography in real-world clinical practice

Contrast-induced encephalopathy following endovascular treatment for intracranial aneurysms-risk factors analysis and clinical strategy

PURPOSE

Contrast-induced encephalopathy (CIE) was defined as new onset of neurological deficits after exposure to contrast media, which could be observed after the endovascular treatment for intracranial aneurysms.

METHODS

We enrolled a consecutive cohort of patients who underwent endovascular treatment for unruptured intracranial aneurysms. CIE was defined as a reversible neuropathic syndrome that occurred after interventional therapy, accompanied by imaging abnormalities and excluding other diseases. Multivariable Poisson regression analysis was performed to show risk factors by incidence rate ratio (IRR) and a clinical strategy was proposed.

RESULTS

Among the 579 patients who underwent interventional therapy for intracranial aneurysms, the crude incidence rate of CIE was 2.4% (95% CI, 1.2-3.6%) at our center. Headache, hemiplegia, and disorientation could be initial symptoms, and cortical blindness was the most common localized deficit. Cerebral edema and sulci effacement on CT were observed, and re-revaluation after treatments on CT/MRI showed absent lesions. The risk factors were history of stroke (IRR, 7.752; P = 0.007), history of hypertension (IRR, 1.064; P = 0.042), posterior circulation aneurysms (IRR, 9.412; P = 0.004) and higher dosage of contrast agents (IRR, 1.018; P = 0.007). After the strategy of accelerating excretion of contrast agents, reduction of intracranial pressure and anti-inflammation/vasospasm therapy, the prognosis was favorable with most patients fully recovered within 72 h.

CONCLUSION

History of stroke and posterior circulation aneurysms were main risk factors for CIE. A higher dosage of contrast agents might induce CIE, and the history of hypertension should be considered as well.

Image quality and diagnostic accuracy of different dosages of iodixanol in computed tomography angiography and perfusion of overweight patients with coronary artery stenosis: A feasibility study

OBJECTIVES

Iodixanol contrast media with different doses using computed tomography angiography (CTA) and perfusion (CTP) to diagnose coronary artery disease (CAD) in overweight patients lacks assessment. Our study compared iodixanol 320 mg I/ml and 270 mg I/ml on image quality and accuracy of CTA combined CTP (CTA-CTP) to diagnose CAD.

METHODS

Overweight patients with suspected of CAD were randomized into iodixanol 270 group (received iodixanol 270 mg I/ml) and iodixanol 320 group (received iodixanol 320 mg I/ml). Based on these characteristics data, receiver operating characteristic (ROC) curve and corresponding area under the curve (AUC) were plotted to assess the sensitivity and specificity of the two administrations.

RESULTS

The subjective definition score, signal to noise ratio, and CT value of aorta in iodixanol 320 group were higher than iodixanol 270 group. In iodixanol 270 group: the image exhibited a normal state of both vessels and myocardial perfusion; and the AUC, specificity, and sensitivity were 0.376, 66.67, and 80.46, respectively. In iodixanol 320 group: the image exhibited a diameter stenosis in right coronary artery and myocardial infarction of inferior wall and proximal inferior wall septum, as well as myocardial perfusion defects; and the AUC, specificity, and sensitivity in iodixanol 320 group were 0.824, 75.00, and 89.87, respectively.

CONCLUSION

Accuracy and image quality of iodixanol 320 mg I/ml in the diagnosis of CAD with CTA-CTP was higher than using iodixanol 270 mg I/ml.

Quantifying image quality in chest computed tomography angiography: Evaluation of different contrast-to-noise ratio measurement methods

BACKGROUND

Contrast-to-noise ratio is used to objectively evaluate image quality in chest computed tomography angiography (CTA). Different authors define and measure contrast-to-noise ratio using different methods.

PURPOSE

To summarize and evaluate the different contrast-to-noise ratio calculation formulas in the current literature.

MATERIAL AND METHODS

A systematic review of the recent literature for studies using contrast-to-noise ratio was performed. Contrast-to-noise ratio measurement methods reported by the different authors were recorded and reproduced in three patients who underwent chest CTA in our department for exploring variations among the different measurement methods.

RESULTS

The search resulted in 109 articles, of which 26 were included. The studies involved 69 different measurements and overall, three different formula patterns. In all three, aorta and pulmonary arteries comprised the objects of interest in the numerator. In the denominator, standard deviation of the attenuation of the object of interest itself or of another background were used to reflect image noise. Some authors averaged the ratio values at different levels to obtain global ratio values. Using the object of interest itself for image noise calculation in the denominator compared to the usage of another background caused the most prominent variances of contrast-to-noise ratio between the two different protocols used for the reproduction of the measurements.

CONCLUSION

We recommend using the standard deviation of the attenuation of a background indicator as image noise rather than the object of interest itself for more reliable and comparative values. Global contrast-to-noise ratios based on averaging the values of different measurement levels should be avoided.