[Contrast-enhanced MR angiography of the arterial and portovenous system of the liver with varying concentrations of contrast medium]. / Kontrastmittel-gestützte 3D-MR-Angiographie des arteriellen und portalvenösen Gefässsystems der Leber mit unterschiedlicher KM-Konzentration.

PURPOSE: To evaluate the diagnostic value of a higher concentrated contrast medium (gadobutrol) for contrast-enhanced MRA of the hepatic arteries and portovenous system. MATERIALS AND METHODS: The examinations were performed on a 1.5-Tesla whole body imaging system (Magnetom Symphony Quantum, Siemens) with a 30-mTesla/m gradient field strength using a phased-array body coil. A 3D FLASH sequence (TR/TE/FA 3.88 ms/1.44 ms/25(3)) was used imaging the hepatic arteries and portovenous system after determination of the circulation time. The study included 50 patients, with 25 patients (group 1) injected with 0.2 mmol Gd-GTPA/kg body weight and 25 patients (group 2) injected with 0.1 mmol gadobutrol/kg body weight. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated for both groups. The image quality was graded by three radiologists on a 5-point scale. RESULTS: The highest SNR was measured in group 1, with no statistically significant differences of the SNR in the abdominal aortal, coeliac trunk and common hepatic artery. CNR was also similar in both groups. Likewise, portal, superior mesenteric and splenic veins showed no statistically significant differences. All cases were found to have a good image quality. CONCLUSION: For MRA of the hepatic arteries and the portal veins, the higher concentrated Gd-DTPA contrast medium gadobutrol can be used at half the dosage recommended for the standard Gd-DTPA contrast medium.

[Experimental evaluation of vessel diameter from 0.3 to 8 mm in CE MR angiography]. / Experimentelle Validierung der Kontrastmittel-verstärkten MR-Angiographie an Gefässdurchmessern von 0,3 - 8 mm.

PURPOSE: To evaluate the detection rate of vascular stenosis in contrast-enhanced 3D MR angiography using a flow phantom. MATERIAL AND METHODS: The examinations were performed on a 1.5 T whole body imaging system (Magnetom Symphony/Quantum) with 30 mT/m gradient field strength using a body-phased-array coil. Different 3D sequences (TR/TE/FA < 5 ms/< 2 ms/25 degrees ) with slice thicknesses ranging from 0.67 to 1.25 mm were applied. A gelantine-filled plastic cylinder with PVC tubes of 8 mm diameter was used as a vascular phantom. The tubes had concentric and excentric stenoses (50 - 90 %) of different lengths. For the detection of different vessel diameters another phantom with 0.3 - 8 mm silicon tubes was used. Both systems were flushed with a solution of Gd-DTPA (0.15 mmol/l) and saline at flow rates from 50 to 200 cm/s. The phantoms were positioned 0 degrees, 45 degrees, and 90 degrees towards the z-axis. RESULTS: The degree of stenosis was under- and overestimated in less than 10 %. The sequence with the highest spatial resolution provided the best results. Detection and evaluation of tubes >/= 2 mm proved to be reliable. CONCLUSION: Contrast-enhanced 3D MR angiography provides an almost exact evaluation of the degree of stenosis in the phantom study. Evaluation of vessel diameters < 2 mm is not possible.

[Impact of different iodine concentrations on abdominal enhancement in biphasic multislice helical CT (MS-CT)]. / Der Einfluss verschiedener Jodkonzentrationen auf die Kontrastierung der Oberbauchorgane im biphasischen Mehrschicht-Spiral-CT.

UNLABELLED: Impact of different iodine concentrations on abdominal enhancement in biphasic multislice helical CT (MS-CT). PURPOSE: To evaluate if different iodine concentrations of a contrast material (c.m.) have an impact on abdominal enhancement in MS-CT during the arterial (AP) and portal venous phase (PVP). MATERIALS AND METHODS: 75 patients underwent biphasic CT of the abdomen. They were assigned to three equally sized groups. For all patients a non-ionic c.m. (iopromide, Ultravist, Schering AG, Berlin) with different iodine concentrations and a constant total iodine load of 37 g with an injection flow rate of 4 ml/s was used. The volume of the c.m. differed depending on the iodine concentrations: group 1 (123 ml of 300 mgl/ml); group 2 (112 ml of 335 mgl/ml); group 3 (100 ml of 370 mgl/ml). The scan delay was optimized by using a bolus tracking device. The groups were compared concerning their mean enhancement of aorta, spleen, pancreas, and liver in the AP and PVP. RESULTS: The comparison of the three groups showed an improved enhancement in aorta, spleen, and pancreas during the AP by using the higher c.m. concentrations. In the PVP the c.m. enhancement of aorta, liver, spleen, and pancreas was independent of the administered c.m. concentration. CONCLUSION: Higher iodine concentrations of c.m. have a positive impact on abdominal enhancement during the AP. The concentration has no influence on the enhancement during the PVP of abdominal MS-CT.

Cardiological effects of catecholamine-secreting tumours.

Correlations between endocrine and cardiological findings were investigated in 106 patients with catecholamine-secreting tumours during the florid phase of their illness. Endocrine data showed an elevation of urinary catecholamine or vanillylmandelic acid excretion in all but one subject. Hypertension was found in 78%, symptoms of coronary heart disease in 26% and arrhythmias in 20% of the patients. Twelve per cent of the patients came to the hospital with heart attacks, 7% with acute left heart failure and 6% with myocardial infarction. At admission electrocardiograph (ECG) analysis showed a sinus rhythm in 98%, tachycardia > 100 min-1 in 14% and bradycardia < 60 min-1 in 10%. In 16% of the ECGs cQT was increased, in 17% the ST segment was lowered and in 37% abnormal T waves occurred. Indices of myocardial hypertrophy such as the Sokolow index, the modified Romhilt-Estes score and the Murphy score were raised in 29%, 19% and 38% respectively. In 23 of 51 (45%) patients echocardiography showed left ventricular hypertrophy, in 16% mitral valve insufficiency and in 24% disturbances of contractility. Comparison of cardiac and endocrine parameters confirm in vitro and animal studies indicating that, in particular, the alpha-mimetic noradrenaline (NA) has deleterious effects on the cardiovascular system. Urinary NA, but not adrenaline or dopamine, excretion was significantly higher in constantly hypertensive than in normotensive patients and associated with an elevation of the Sokolow index and the Romhilt-Estes score. Both indices and plasma NA were higher in patients with myocardial hypertrophy and we found a significant correlation between the Romhilt-Estes score and NA excretion.

[Symptoms and endocrinologic features of catecholamine-secreting tumors. Results in 106 consecutive patients]. / Symptomatik und endokrinologische Befunde bei katecholamin-sezernierenden Tumoren. Ergebnisse bei 106 konsekutiven Patienten.

The clinical and endocrinological features in 106 patients (40 men, 66 women, mean age 48 +/- 14.3 years) treated between 1973 and 1993 for proven catecholamine-secreting tumours (phaeochromocytoma: n = 88, paraganglioma: n = 10, adrenal medullary hyperplasia: n = 8) were analysed. The most frequent symptoms were palpitations (68%), severe sweating (53%) and headache (42%). 10% of patients were symptom-free. 58% of patients had consistently raised blood pressure, and 20% of patients suffered paroxysmal blood pressure crises. However, 22% of patients did not have hypertension. Raised urinary catecholamines were found in more than 95% of cases; MIBG (metaiodobenzylguanidine) scintigrams were abnormal in more than 85% of cases. Patients with catecholamine-secreting tumours do not always have "classical" features. The high sensitivity of properly performed catecholamine measurement on plasma and urine has made dangerous stimulation and suppression tests obsolete.