Contrast medium incidence

Katzberg RW Acute reactions to urographic contrast medium incidence, clinical characteristics, and relationship to history of hypersensitivity states - a commentary. AJR Am J Roentgenol 2008 190 1431-1432. 

Also technical aspects may contribute to the variable incidence of parenchymal enhancement in acute human stroke. With double dose contrast medium and a time lag between injection and imaging, every fourth stroke patient showed tissue enhancement within 24 h of stroke onset (Karonen et al. 2001). Widespread parenchymal enhancement in Tl-w images seems to gradually develop over the first week when simultaneously the diffusion changes tend to pseudonormalize. Without precise clinical history confounding with tumor enhancement may occur and should be ruled out by observation of the time profile of MR contrast enhancement and DWI. 

The incidence of urolithiasis with indinavir has been estimated at 9% (19) but, according to some, may be as high as 20%. Indinavir calculi are often radiolucent and may be missed on CT scan rather than by using a contrast medium (which is itself not without risk) (20,21). It may therefore be that in some cases in which other renal complications with indinavir have been described there was in fact undetected renal stone formation. Any patient taking indinavir who develops renal cohc should be suspected of having renal stones (22). 

Delayed reactions are generally benign, but not always. In a Japanese study, the incidence of delayed reactions was investigated in 6764 patients who received the low-osmolar non-ionic contrast medium iohexol intravenously (33). Delayed reactions (rash, pruritus, nausea, vomiting, fever, headache, and others) occurred in 192 patients (2.8%). There were no severe delayed reactions. A history of allergy and hay fever were risk factors for delayed adverse reactions. 

Contrast media can cause severe bronchospasm, particularly in patients with asthma (72). Subclinical bronchospasm can occur after bolus injections of ionic contrast medium the incidence is lower with non-ionic media (SEDA-8, 427). 

In patients with pre-existing renal impairment, hemodialysis did not influence the incidence or outcome of contrast-induced nephropathy, in spite of eliminating contrast agents effectively from the circulation. The same group has now confirmed their previous observation in a bigger study in 30 patients with pre-existing renal impairment (184). Hemodialysis did not influence the incidence or outcome of contrast-induced nephropathy, in spite of effective elimination of contrast medium from the circulation. The failure of hemodialysis to protect against the development of contrast nephropathy is due to the very rapid onset of renal injury after the administration of contrast medium. 

The protective effects of intravenous hydration alone (0.45% isotonic saline, 1 ml/kg/hour for 12 hours before and 12 hours after contrast administration), fenoldopam (0.1 microgram/kg/minute for 4 hours before and 4 hours after the procedure), and acetylcysteine (600 mg bd 24 for hours before and 24 hours after the procedure) have been compared in preventing contrast nephrotoxicity after intravascular administration of low-osmolar non-ionic contrast medium (199). The incidence of nephrotoxicity was 15% in the hydration group, 16% in the fenoldopam group, and 18% in the acetylcysteine group. AU the groups were comparable and basehne creatinine clearance was about 60 ml/minute in aU the patients who received a similar dose of the contrast medium (1.5 ml/ kg). The authors concluded that fenoldopam and acetylcysteine do not offer extra protection against contrast nephrotoxicity over hydration alone. 

A pouchogram of the atretic proximal esophagus is not usually necessary because of the low incidence a fistula from the proximal pouch (Fig. 2.9). In addition, this is a dangerous procedure if improperly performed. Air or non-ionic isotonic contrast medium can be injected to distend the pouch (Fig. 2.10). Over distention of the pouch with contrast medium will invariably result in aspiration so only a small volume of contrast medium, not exceeding 1-2 ml, is injected into the blind-ending pouch with the child in the true lateral position. Contrast medium must be removed at the end of the procedure. 

An allergic or idiosyncratic reaction related to the contrast medium can occur after HSG, although the incidence is unknown and is presumably quite low. 

There were adverse events in 241 patients (2.7%), and the incidence was significantly higher with iomeprol (3.9%) and iopromide (3.5%), in patients aged 59 years or less (4.5%) compared with those 60 years and over (1.9%), during the first period of the study (3.5%) compared with the last period (2.3%), in those with a past history of adverse reactions to contrast media (11%) and in patients receiving a contrast medium for first... 

More recently referred to as contrast-induced acute kidney injury (CIAKI), contrast medium-induced nephrotoxicity can occur after intravascular administration of iodinated contrast media. It is the third leading cause of acute kidney failure in hospitalized patients in the USA and Europe [11 ]. It leads to prolonged hospital stay and is associated with increased long-term morbidity and mortality. Traditionally it has been defined as an acute rise in serum creatinine by at least 44 pmoUl (0.5 mg/dl) or at least 25% above baseline within 48-72 hours of administration. The incidence is 5-50% [125], depending on the... 

A curious seasonal variation in the occurrence of late adverse skin reactions has been reported from Finland. In a study of a possible relationship between sun exposure and late reactions in 4,875 adults who had received an iodinated contrast medium, a 3-month (April to June) peak in the incidence of reactions was seen. This period included 35 % of all events and most of the reactions occurred on sun-exposed areas of the body, leading the authors to conclude that a possible explanation for the observations was the photosensitizing effect of the contrast media. 

Nonionic iodinated contrast media (2ml/kg) are preferred because they have been shown to decrease the incidence of minor events (K ataya m a et al. 1990). Diluted barium sulfate can be administered per os (the preferred drink of the child is recommended for dilution) or by enema to beacon the digestive tract. A child with a proven history of a severe accident with iodinated contrast medium should be referred to an allergist and an anesthesiologist who will make medical decisions about any further injection. In case a new injection is mandatory, a different contrast medium... 

The end product of any examination is the radiological report. A successful examination includes a clear and well-built report. Blais and Sanson (1995) published an excellent guide for reports that refers to the model of a scientific article. Introduction puts examination in the clinical context. The referring physician can check that the question was properly understood. The Patients and Methods section describes the technique. The procedural features, amount and nature of contrast medium, venous access, and incidents are indicated. Such information is valuable in case of follow-up. Then, in the Results section, pertinent radiological... 

Wangermez (15 ) noted that when corticosteroids were given prior to intravenous cholangiography, the biliary excretion of the contrast medium was decreased and the urinary excretion was increased, so that there was impaired visualization of the biliary tract. Similar impaired biliary excretion of ioglycamate has been observed in diabetic patients during treatment with sulphonyl-ureas, in this case associated with an increased incidence of side effects (16 ). Impaired biliary excretion of the cholangiographic media in these circumstances may be due to competition for protein-binding or to competition at the hepatic excretory level. 

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