Effect of ionic and non-ionic contrast medium on aortic and pulmonary arterial pressure. An angiocardiographic study in rabbits.

Effects in angiocardiography from injections into the right atrium of rabbit hearts of a new, non-ionic contrast medium (Amipaque) were studied and were compared with the effects from injections of an ionic medium (Isopaque Coronar) at a dose of 3 ml/kg rabbit and concentration of 370 mg I/ml. Forty-seven experiments in 11 rabbits are reported. Amipaque produced a significantly (p less than 0.001) smaller increase in pulmonary arterial pressure (29%) than Isopaque Coronar (82%). Simultaneously (within 12 seconds from the beginning of an injection) Amipaque produced an increase in aortic pressure of 21%. About 10-15 seconds later when the contrast media had reached peripheral vessels Amipaque produced a significantly (p less than 0.001) smaller decrease of aortic pressure (12%) than the decrease produced by Isopaque Coronar (40%). The differences found between the two types of contrast media are believed to be related to, among other factors, their different osmolality. The osmolality of Amipaque was about one third of the osmolality of Isopaque Coronar.     

Amipaque: a new contrast medium in coronary angiography. Report of a double-blind study in man.

Isopaque Coronar and Amipaque (metrizamide) were evaluated in a comparative double-blind study of 30 patients with heart disease undergoing selective coronary angiography. Amipaque alone was also used for 9 additional patients undergoing left ventriculography, aortic root injection, and selective coronary angiography. Amipaque resulted in significantly less of a decrease in diastolic pressure and heart rate, reduced chest pain and heat sensation, and longer coronary contrast transit time. Electrorocardiographic parameters and image quality were equivalent with the 2 agents. No pathological changes were noted in the 9 patients undergoing complete angiocardiographic study.     

Amipaque as contrast medium for intraosseous phlebography.

The degree of pain produced by Amipaque 260 and Isopaque 260 at intraosseous phlebography in patients with varicose ulcerations in the ankle region was compared. Amipaque produced less pain than Isopaque. No complications or side-effects occurred during the observation period of about one year.     

Arthrography with Amipaque (metrizamide) and other contrast media. A roentgenographic and histologic evaluation in rabbits.

Arthrography of the knee joint was performed in 30 rabbits for comparison of Amipaque (metrizamide) with Urografin 60% (meglumine-sodium diatrizoate), Isopaque Amin (meglumine-calcium metrizoate), Conray Meglumin 282 (meglumine iothalamate) and Dimer-X (meglumine iocarmate). Films taken at regular intervals show longer contrast duration, and less hydrarthrosis after injection of Amipaque. Minimal focal inflammatory reaction in the synovial membrane is found in many cases when the animals are sacrificed 1 day or 7 days after the injections. No significant difference can be found between the contrast media, and similar changes are also seen after injection of physiologic saline.     

Comparative double-blind investigation of meglumine metrizoate, metrizamide, and iohexol in carotid angiography

The new nonionic contrast medium iohexol (Omnipaque) was compared with its predecessor metrizamide (Amipaque) and with the conventional ionic medium meglumine metrizoate (Isopaque Cerebral) in carotid angiography using a double-blind crossover technique. The results indicated that iohexol and metrizamide caused less discomfort than the ionic medium. The circulatory effects of the three media were generally mild, and the diagnostic effectiveness was comparable when the iodine concentration was kept in the range of 280-300 mg I/ml.     

Clinical testing of amipaque for cerebral angiography

Summary Amipaque 280 mg I/ml was compared to Isopaque Cerebral 280 mg I/ml for common carotid injection in twenty patients in a double blind trial. Simple comparison was also performed in examinations with selective external carotid injections. The reaction of the patients to the common carotid injection was mild on the whole but Amipaque caused significantly less discomfort than Isopaque. Selective external carotid injection of Amipaque caused very little discomfort while most patients complained of severe pain when Isopaque was used. No serious side-effect was observed.Read at the Annual Meeting of the Scandinavian Society of Neuroradiology August 31 1977, and at the 7th Congress of the European Society of Neuroradiology September 10 1977     

Hysterosalpingography with Amipaque.

The authors report their initial experience with Amipaque (metrizamide) in hysterosalpingography. Amipaque was compared to Isopaque Cerebral in 37 patients, using a double-blind design. Excellent radiographs were obtained with both agents. No statistically significant difference in discomfort and pain was found up to 24 hours after the procedure. However, the aftereffects indicate that Amipaque might be less irritating to the pelvic peritoneal cavity.     

Iohexol compared with metrizoate in urography

Urography was performed in 20 patients using the new non-ionic contrast medium iohexol (Omnipaque) and in 22 patients using the conventional ionic medium metrizoate (Isopaque) in a randomized, double blind comparison. Iohexol caused significantly less subjective reactions and less tachycardia than metrizoate. No significant difference between the contrast media was observed regarding the influence on blood pressure, hematologic parameters, or clinical chemical parameters in blood and urine. Urographic films of similar and high quality were obtained with both contrast media.     

The toxicity of the non-ionic watersoluble contrast medium metrizamide (Amipaque) in selective vertebral angiography

Summary Selective left vertebral angiography was carried out in 21 rabbits comparing the toxic effects of meglumine iothalamate (Conray meglumine), meglumine metrizoate (Isopaque Cerebral) and metrizamide (Amipaque). The iodine concentration for all 3 media was 280 mg/ml. General convulsions were seen in many of the animals with all 3 media. The convulsions occurred at higher doses and were milder with metrizamide than with the 2 other contrast agents. Bradycardia was also seen with all 3 media and there was no statistical significant difference between them in this respect. The mortality was approximately 50% with both meglumine iothalamate and meglumine metrizoate, while no animals died following angiography with metrizamide.     

Iohexol in coronary angiography. A double blind investigation

Iohexol 350 mg I/ml (Omnipaque) was compared with the routine contrast medium meglumine, Na-Ca-metrizoate 370 mg I/ml (Isopaque Coronar) in coronary angiography in 30 patients. A randomized, double blind, crossover design was employed. Angiographic image quality, ECG, heart rate, aortic blood pressure and adverse reactions were recorded. Excellent image quality was obtained with both media. Except for one single event of hypotension, only few and minor changes in the parameters measured were recorded. No distinct difference between the two media was found. Iohexol seems to be suitable for selective coronary angiography.     

Knee arthrography: a comparison of iohexol, ioxaglate sodium meglumine, and metrizoate

The arthrographic image quality and relative morbidity resulting from use of Omnipaque 300 (iohexol), Hexabrix 320 (ioxaglate sodium meglumine), and Isopaque Coronar 370 (metrizoate) were compared in a prospective double-blind study performed with 120 patients. Radiographs obtained 2, 5, 10, 15, 20, and 25 minutes after injection were judged for diagnostic quality. Relative morbidity was evaluated by the physician during the examination and later by the patient via a questionnaire. Hexabrix demonstrated the best and most persistent diagnostic quality over serial radiographs (P less than .05). Omnipaque caused significantly less postprocedural pain (P less than .05). The other types of discomfort measured did not indicate statistically significant differences in morbidity resulting from the three contrast agents.     

Amipaque in coeliac angiography

Coeliac angiography was performed in 12 patients using Amipaque 370 mg I/ml or Isopaque 370 mg I/ml. No significant biochemical alterations were found in serum. Amipaque improved the demonstration of small vessels in the liver and in the head of the pancreas. Amipaque caused no discomfort contrary to Isopaque, which gave moderate to severe heat during injection.     

The effect of position of patient on the passage of metrizamide (Amipaque), meglumine iocarmate (Dimer X) and ioserinate (Myelografin) into the blood after lumbar myelography

Lumbar myelography was carried out with the contrast media Amipaque, Dimer X and Myelografin in 10 patients each. Five of the patients treated with each contrast medium were kept in a sitting position after the examination, the others lay flat. Blood levels and excretion were measured up to 24 h. The results are interpreted as follows: 1. After lumbar injection of the contrast media there is a short phase of distribution in the subarachnoid space (lag time) and they then are transferred into the blood with a half-life of 3.9 +/- 2.4 h. The transport from the CSF is almost completed approximately after 24 h. The velocity of transport varies greatly between the individual patients. Watersoluble contrast media presumably flow passively with the CSF through the arachnoid villi into the venous blood. 2. The horizontal position of the patient reduces the lag time until the beginning of the actual transfer of the contrast medium. 3. The transfer of Dimer X begins somewhat later compared with Amipaque and Myelografin.     

Antibacterial effects of metrizoate and metrizamide on bacterial growth in vitro.

Urinary pathogens were exposed in vitro to Isopaque and Amipaque in concentrations of 100 mg I/ml and 260 mg I/ml. Both contrast media in the higher concentration had a slight or negligible bacteriostatic effect on some of the test bacteria. No bactericidal effect was detected. Consequently, radiography of the urinary tract with these two media in the concentrations mentioned does not interfere with the culturing of bacteria from urine samples.     

Hemodynamic effects of a new iso-osmotic contrast medium in selective left ventriculography

To evaluate the myocardial hemodynamic effects of a new iso-osmotic contrast agent (Hexabrix 160: H 16) a randomized cross-over study was performed comparing Hexabrix 160 with Sodium Meglumine diatrizoate (Radioselectan 76: R 76) in 20 patients with ischemic heart disease. H 16 produced substantially smaller (p less than 0.001) increases in heart rate (68 +/- 11 to 73 +/- 12) than R 76 (69 +/- 12 to 88 +/- 15) and smaller decreases in left systolic ventricular pressure (131 +/- 15 to 128 +/- mmHg) than R 76 (132 +/- 14 to 94 +/- 15 mmHg). Both contrast media resulted in an increase in contractility beginning three to five seconds after the onset of the injection and reached its maximum at 45 seconds. However the increases in contractility was smaller with H 16 than R 76: H 16 caused a significantly smaller (p less than 0.01) increases in V max. (0.1 CIRC/s) than R 76 (0.35 CIR/s). The hemodynamic effects of H 16 were probably in relation with the Frank-starling mechanism. The lowest variation of preload observed (left ventricle end-diastolic pressure: 12 +/- 4 to 14 +/- 5 mmHg) showed that this contrast medium appeared to behave like isotonic serum. These results suggest that H 16 may preferable for digital left ventriculography.     

Randomized double-blind cross-over study of iohexol and Amipaque in cerebral angiography

Iohexol was compared with Amipaque (metrizamide) in a double-blind study in one pair of injections in each of 20 patients referred for routine cerebral angiography. Catheter position, patient position, injection pressure, contrast medium volume, and concentration (300 mg l/ml) were the same in the two injections, with iohexol and Amipaque being used alternately. Except for these two injections iohexol was used throughout. The parameters studied included diagnostic information obtained (quality of the examination), circulation time, and comparison of patient reactions to the pair of injections (e.g., electrocardiogram, heart rate, and subjective reactions). The patients' reactions to the noncomparative part of the examination were evaluated also, and the patients were observed for possible adverse reactions after the examination. No difference could be detected between the two contrast media in this series. No serious adverse reactions occurred.     

Clinical testing of Iohexol,Conray meglumine and Amipaque in cerebral angiography

Summary Iohexol 300 mg I/ml, Conray meglumine 282 mg I/ml and Amipaque 300 mg I/ml have been compared in a randomized double-blind cross over study in which one injection of Iohexol 300 mg I/ml and Conray meglumine 282 mg I/ml was made in the same artery (common and internal carotid artery) of the same patient, and one injection of Iohexol 300 mg I/ml and Amipaque 300 mg I/ml was made in another artery (external carotid artery and vertebral artery). All together 63 cerebral artery branches were examined in 27 patients, who served as their own controls. The effect of the contrast injections on the intraarterial blood pressure, pulse rate, ECG, circulatory rate and the patients' reactions were recorded under standardized conditions. The quality of the film was also evaluated. No significant difference was found in the cardiovascular effects after the injection of Iohexol or Conray meglumine into the common carotid or internal carotid. There was significantly less pain and sensation of warmth after the injection of Iohexol than after Conray meglumine 282. In the vertebral and the external carotid arteries, where a comparison between Iohexol and Amipaque was carried out, it was found that no significant difference in the cardiovascular effects occurred. There was less sensation of warmth after the injection of Amipaque into the vertebral artery than was caused by Iohexol. The degree of discomfort in form of pain reaction was the same for the two media, when these reactions occured. No serious side effects were observed.Read at the Annual Meeting of the Scandinavian Society of Neuroradiology, August 1981     

Clinical testing of omnipaque and amipaque in external carotid and vertebral angiography: randomized double-blind crossover study

Omnipaque, 300 mg l/ml, was compared with Amipaque, 300 mg l/ml, for cerebral angiography. Twelve patients were included in a randomized, double-blind, crossover study. Twenty comparisons were made in the external carotid and 21 in the vertebral artery, Both contrast media caused no or minor changes in blood pressure and heart rate. Good to excellent radiographic visualization of the cerebral arteries was obtained with both agents. The frequency of subjective reactions was almost equal, but the intensity of the reactions was less with Amipaque. No severe reactions were observed. Omnipaque is a more practical nonionic contrast medium than Amipaque because it is delivered in ready-to-use solutions.     

Iopamidol and metrizamide in cervical myelography: side effects, EEG, and CSF changes

Two nonionic contrast media, iopamidol and metrizamide (Amipaque), were used for cervical myelography (C1-C2 puncture) in 95 consecutive patients. Both contrast media gave excellent radiographic results. Headache and vagal symptoms were similar in both groups, whereas metrizamide produced more electroencephalographic changes and epileptic seizures. Meningeal irritation occurred in both groups and was severe in three cases. Cerebrospinal fluid showed protein and cellular changes of inflammatory type in both groups. Iopamidol is considered to be the more suitable contrast medium for cervical myelography despite its slight neurotoxicity.     

Arthrography of the knee joint with amipaque.

In a double-blind investigation, 30 knee arthrographies were performed by injection of either Amipaque 290 mg I/ml or Urografin 60% (292 mg I/ml). Both contrast media are well tolerated, and give excellent initial contrast quality, which deteriorates rapidly. This occurs more slowly with Amipaque, which has lower osmolality and causes less joint effusion.