The aim of this study was to investigate the contrast effects of gadolinium (Gd) in patients undergoing digital subtraction angiography (DSA), intravenous urography (IVU) and CT. 15 patients attending for coeliac axis DSA (n = 5), abdominal CT (n = 5) and IVU (n = 5) were injected with 0.3 mmol kg-1 Gd-DTPA, the maximum approved dose. For DSA and IVU, images were categorized as being of diagnostic or non-diagnostic quality. For CT, enhancement was measured in Hounsfield Units (HU). On CT, enhancement with Gd was reproducible in all cases; average peak aortic enhancement was 75 HU but duration was short. On IVU, four of five studies yielded positive pyelograms but all nephrograms were relatively poor. On DSA, all five patients had diagnostic arteriograms and four of five indirect portograms were of diagnostic quality. In all 15 cases, enhancement was weaker than that achieved with routine dosage of iodinated agents. In conclusion, Gd chelates may be clinically useful in X-ray studies under certain circumstances on patients with contraindications to iodinated agents. Higher doses than currently approved would be potentially useful.

This study evaluated the use of dobutamine stress echocardiography and exercise thallium-201 myocardial computed tomography (CT) in the diagnosis of coronary artery disease (CAD) in patients with permanent transvenous pacemaker with the electrode implanted in the right ventricle (RV). Twenty-nine consecutive patients with pacemaker underwent dobutamine stress echocardiography, exercise thallium-201 myocardial CT, and coronary arteriography over a period of 8 +/- 1 days. None of these patients had suffered a myocardial infarction (MI). The cardiac rhythm of every patient was electrically paced during echocardiography and tomography. Sixteen (55%) patients showed CAD on angiography (stenosis > or = 50% of the luminal diameter of a major epicardial vessel). The detection sensitivity for CAD was 94% for the tomography and 88% for the echocardiography (P = NS). The difference between the sensitivities of the two techniques in detecting CAD based on the affected coronary artery was not statistically significant. Of the 13 patients without CAD, tomography showed a positive result in nine cases, i.e., a specificity of 31%, whereas echocardiography showed a positive result in only one case, i.e., a specificity of 92% (P < 0. 01). Exercise thallium-201 myocardial computed tomography produces an increased rate of false-positive results in patients with permanent transvenous cardiac pacemaker (PCP) implanted in the right ventricle (RV). Dobutamine stress echocardiography can thus be used to reduce considerably the level of false-positive results in these patients and still retain a detection sensitivity for CAD equal to that of myocardial tomography.

First observations indicate that LITT of hepatic metastases can be better followed with double contrast MRI, which displays increased contrast due to Gd enhancement of perfused tumor tissue and signal intensity loss in iron oxide accumulating hepatic parenchyma. Induced necrosis does not change its signal intensity at all after injection of iron oxide and Gd-containing contrast media.

84 knee joints were examined by a 3-dimensional MR method and the results correlated with subsequent arthroscopy. The findings showed good demonstration of the normal anatomical structures and excellent reliability for the diagnosis of meniscus tears (sensitivity 91%, specificity 95%), cruciate ligament lesions (sensitivity 90%, specificity 99%) and serious cartilage damage (sensitivity 100%, specificity 100%). Demonstration of mild cartilage damage (sensitivity 60%, specificity 99%) was better than with a spin echo technique but is not yet optimal. It is concluded that, by using a 3-dimensional technique, time-consuming spin echo sequences can be abandoned. Significant advantages of the 3-D method are the speed of the examination, narrow section thickness, marked flexibility in contrast rendering and the ability for multiplanar reconstruction.

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