Absorbed dose and image quality in examinations of the colon with digital and analogue techniques.

PURPOSE: Image quality and the absorbed dose to the patient are issues of primary interest in the change-over from the conventional analogue technique to the digital technique in the examination of the colon by means of fluoroscopy. The aim of this study was to compare the incident radiation and to evaluate the image quality in two different X-ray equipment types, one digital and one analogue. MATERIAL AND METHODS: A kerma-area product meter was used to measure the incident radiation to the patient. Both fluoroscopy and total-examination times were measured as was the number of images. An evaluation of image quality was made and statistically analysed. RESULTS AND CONCLUSION: No significant difference in the irradiation dose was observed between the two techniques. The fluoroscopy time was significantly lower with the conventional technique but the total-examination time decreased by 18% with the digital technique. The total number of images taken was higher with the digital technique (25 images compared to 19) owing to the limited field of the image intensifier. Significantly more noise and less sharpness were observed with the digital system but there was no significant difference in contrast or image quality in the various anatomical structures. Although the change-over to the digital system produced a reduction in sharpness and an increase in noise, and no significant dose saving was measured, the digital system was faster to work with and could well be used for diagnostic purposes.

Contrast media and pain in patients with acute ureteral stone obstruction. A comparative study with iohexol and metrizoate.

A randomized study was conducted in 43 patients who were in pain due to acute ureteral obstruction. Emergency urography was performed in all patients, using either a low osmolar non-ionic (iohexol) or a high osmolar ionic (metrizoate) contrast medium. Increase of pain following injection of contrast media was found in 56 percent of all patients. Increase of pain occurred with both contrast media without any difference between the degree of pain nor the number of patients who experienced an increase of pain. Delayed excretion was considered the only reliable indicator of the degree of obstruction in the present study. Nineteen (68%) of the 28 patients with a delayed excretion greater than 10 min experienced increased pain while the incidence of pain increase was significantly lower (33%) in patients without that sign of ureteral obstruction (p less than 0.05). The increase of pain was not associated with a simultaneous increase of the mean arterial blood pressure.

Systemic, pulmonary and renal haemodynamic effects of intravenously infused iopentol. A comparison in the pig of a new low osmolar non-ionic medium with saline and iohexol.

The central, peripheral and renal haemodynamic effects after intravenous infusion (1 ml/s) of high doses (4 mg I/kg) of two low osmolar, chemically and physically similar non-ionic contrast media (iohexol and iopentol) were investigated in 16 pigs. Both contrast media induced a significant increase of mean arterial, mean right atrial, mean pulmonary arterial and mean pulmonary arterial occlusion pressure along with an increase in cardiac output. The systemic vascular and pulmonary vascular resistances were decreased. Renal venous blood flow and renal vascular resistance were not significantly changed after infusion of contrast media. There were no differences in haemodynamic effects between the two media studied.

Systemic, pulmonary and renal haemodynamic effects of large intravenous doses of high and low osmolar contrast media. An investigation in the pig of ratio 1.5 and ratio 3 media.

The central, peripheral and renal haemodynamic effects of intravenous infusion (1 ml/s) of large doses (4 ml/kg body weight) of non-ionic (iohexol) and ionic (metrizoate and ioxaglate) contrast media were studied in 24 anaesthetized pigs. All contrast media showed marked haemodynamic effects with an increase of mean right atrial pressure, mean pulmonary arterial pressure, mean pulmonary occlusion pressure, cardiac output and stroke volume. The response of the pulmonary circulation to contrast media was a fall rather than a rise in pulmonary vascular resistance. No significant changes were detected in the renal circulation after infusion of contrast media.

Nephrotoxicity of contrast media in patients with diabetes mellitus. A comparative urographic and angiographic study with iohexol and metrizoate.

A double-blind urographic and angiographic study was done with the ionic contrast medium meglumine metrizoate and the non-ionic iohexol in 90 patients with diabetes mellitus. Twenty patients were insulin dependent, and 70 non-insulin dependent diabetics. Diabetic patients with decreased as well as normal renal function prior to the examination sustained a reversible and small increase in the plasma creatinine level postexamination. The small increase caused by meglumine metrizoate was significantly higher than the increase caused by iohexol. There was also a significantly higher increase in plasma creatinine among the patients with diabetic nephropathy compared with those without nephropathy.

Effects of contrast media on renal graft function and survival after cerebral angiography of cadaveric donors.

The effects of intravascularly administered ionic contrast media on renal graft function and survival were retrospectively evaluated in 211 recipients of cadaveric renal transplants. The renal grafts were explanted from the donors within 24 hours (mean 16 hours) after cerebral angiography. There were no differences in renal function or graft survival between those exposed and those not exposed to contrast media before nephrectomy.

Cystadenocarcinoma of the pancreas 9 years after a pancreatic cyst operation: report of a case.

A patient case with cystadenocarcinoma of the pancreas in a middle-aged woman is described. Nine years prior to the pancreatic malignancy she underwent cystogastrostomy due to a pancreatic cyst presumed to be of non-neoplastic nature. The malignancy occurred at the site of the previous cystogastrostomy and was radically resected. Five years later the patient was well without signs of recurrence. The possibilities of incorrect primary diagnosis or development of a rare pancreatic malignancy in a previous cystogastrostomy are discussed.

Effects of metrizoate and iohexol on the liver at visceral angiography.

Hepatic angiography was performed in a double-blind two-group study in 60 patients using iohexol 350 mg I/ml and metrizoate 350 mg I/ml. A slight increase in serum values of hepatic enzymes was found when metrizoate was used, particularly in patients with impaired liver function. Iohexol gave considerably less pain and sensation of heat than did metrizoate. A non-expected significant increase of creatine kinase was recorded when iohexol was used. The reason for this is not yet known.

Anatomic variations of the accessory soleus muscle.

Four cases of accessory soleus muscle are presented. By means of soft tissue radiography and computed tomography the course of the accessory muscle as well as its exact site and mode of insertion could be determined. It was found that the accessory muscle in these four cases showed four different varieties of insertion, i.e. along the tendon of Achilles, fleshy to the upper surface of the calcaneus, by a separate tendon to the upper surface of the calcaneus and fleshy to the medial surface of the calcaneus. These variations may be of importance in the planning of operative treatment. Therefore, meticulous radiologic examinations as depicted in this study are recommended before surgery.

Central and renal haemodynamic effects of intravenous infusion of non-ionic and ionic contrast media. An experimental investigation in the pig.

The central and renal haemodynamic effects after intravenous infusion (1 ml/s) of a non-ionic (iohexol) and an ionic (metrizoate) contrast medium were investigated in 16 pigs. The injected contrast media induced marked haemodynamic changes compared with normal saline. However, there were no significant differences between the ionic and the non-ionic media. It was concluded that the effects were only partially caused by an increase in the blood volume due to the injected volume. In addition, the effects related to the viscosity, the osmolality and other not specified pharmacodynamic properties of the media are proposed to be of importance.

The vascular supply of the rat tympanic membrane.

The vascular supply of the rat tympanic membrane (TM) was studied by means of otomicroscopy, angiography, acrylic casts, and light microscopy. The branches of the external carotid artery in the external auditory meatus were found to vascularize 1) the pars flaccida, 2) the manubrial part of the pars tensa, and 3) the junction between the fibrocartilaginous ring of the TM and the tympanic sulcus of the temporal bone. The TM vessels of areas 1 and 2 were found beneath the squamous epithelium, close to mast cells and nerve bundles. Vessels originating from the tympanic cavity (also probably emanating from the external carotid artery) supplied the periphery of the pars tensa with minute branches, localized immediately beneath the tympanal epithelium. The portion of the pars tensa between the manubrial part and the periphery lacked a vascular system. Upon mechanical stimulation (gentle pressure on the handle of the malleus), the normally visible vessels dilated and minute branches appeared. This dilation may be caused, at least partly, by a release of vasoactive substances from mast cells and/or nerves in its vicinity. Even under mechanical stimulation, a large portion of the pars tensa seemed to be devoid of vessels. The nutrition of this part may be served by diffusion, with nutrients originating from the vessels in the tympanal rim and along the handle of the malleus. The architecture of the attachment of the fibrocartilaginous ring to the bony sulcus of the temporal bone is quite unique. Thus, the flow in the dense vascular network between these structures may be affected by an altered tension in the pars tensa.

Increased content of saliva cortisol following infusion of ioglycamate.

The release of steroid hormones from protein bound stores by ioglycamide has previously been confirmed by clinical and experimental findings. Increased saliva cortisol levels were observed following intravenous infusion of ioglycamate. Saliva cortisol content was measured before and after ioglycamide infusion in routine clinical examinations. The saliva steroid level has been shown to concur well with the serum level of free steroids. Thus, the increase of cortisol in saliva would indicate the release of cortisol from serum proteins by ioglycamate.

Ioglycamide induced release of testosterone and estradiol from protein bound stores.

With the use of an aqueous two-phase system the effect of ioglycamide (Bilivistan) on the binding of testosterone and estradiol to albumin and testosterone-estradiol-binding globulin was investigated using whole human serum. Reduced binding capacity was recorded for TeBG and a reduced apparent association constant for the testosterone-albumin binding was recorded in the presence of ioglycamide in high concentration. The significance of reduced binding of testosterone and estradiol to albumin and TeBG was discussed in relation to side-effects of radiographic contrast media.

Binding of a metrizamide to human serum proteins.

In connection with the introduction of the non-ionic radiographic contrast medium metrizamide (Amipaque) Salvesen & Frey reported that no significant albumin binding of metrizamide could be revealed by the use of equilibrium dialysis. The protein binding of metrizamide has now been investigated using whole human serum with the aid of an aqueous two-phase system and gel electrophoresis. No binding to serum proteins, at least not to others than albumin could be demonstrated. The possible existence of a minor (less than 1%) protein binding is discussed.

Adverse reactions at intravenous cholegraphy with ioglycamide. Correlation with the level of circulating sex hormones.

Intravenous cholegraphy with ioglycamide was performed in 861 cases. The patients were divided into hormonally disparate age groups. The phase of the menstrual cycle was recorded. A correlation was demonstrated between the incidence of side effects and the level of circulating sex hormones at the time of examination. The possible mechanisms for these adverse reactions are discussed.

Release of protein bound progesterone in human serum by ioglycamide.

With the use of an aqueous two-phase system the influence of ioglycamide on the serum protein binding of progesterone was investigated. Ioglycamide was found to cause a decrease in the association constants for the binding of progesterone to both albumin and transcortin. The binding capacity for the progesterone binding to transcortin was also decreased. The decreased progesterone binding was discussed in terms of clinical relevance in connection with adverse reactions at cholegraphy with intravenous injection of ioglycamide.

Occlusion of the carotid artery using catheter with detachable balloon in pigs.

A new catheter with detachable balloon for vascular occlusion was successfully used for permanent occlusion of the internal carotid artery as well as branches of the external carotid artery in 5 pigs. The technique is intended for clinical use in man.

Giant serpentine intracranial aneurysm after carotid ligation. Case report.

A case is reported of a giant aneursym of the intracavernous portion of the left internal carotid artery that was treated initially with a left common carotid artery ligation. Six months later the aneurysm was partially removed. During this time the development and evolution of thrombus formation, a serpentine channel, and a hypervascular capsule was easily followed with recreated computerized tomography and angiography of the aneurysm.

Quantitative estimation of tumor volume on computer assisted tomography.

With the use of computer assisted tomography (CAT), the volume of intracranial hemorrhages can be calculated. The present work outlines a method that, based on EMI scan printouts, makes possible a calculation of the volume of hemorrhages, tumors, or other pathological changes detectable on CAT with a high degree of accuracy, even when the pathological changes are irregular in shape. Thus, there have been divergences between the estimations of volume of meningiomas using this method and the measure of the volume of the enucleated meningiomas within the range of 0 to +5%. An example of such a meningioma, and the calculation of its volume, is presented.