Myocardial response to contrast media: effects on electrolyte metabolism and subcellular structures.

The success of coronary angiography depends upon appropriate use and administration of contrast media. We used guinea-pig hearts to study tolerance to various contrast media, with particular attention to electrolyte changes. Changes in myocardial subcellular structures appear to correspond to changes in electrolyte flow produced by contrast media.

[Syringomyelia and normal pressure hydrocephalus (author's transl)]. / Syringomyelie und Normal Pressure Hydrocephalus

A case of syringomyelia with coexisting hydrocephalus is reported and a pathogenic relationship between both conditions is discussed. Gardner proposed that anomalies at the exit of the fourth ventricle produce a communicating syringomyelia. Hakim and Adams maintain that normal pressure hydrocephalus can aggravate this condition by a hydraulic pressure effect which can be stopped by the insertion of a ventriculoatrial shunt with improvement in the clinical picture. This has been our experience in the case reported.

Unusual cause of recurrent arterial embolism: floating thrombus in the aortic arch surgically removed under hypothermic cardiocirculatory arrest.

A 46-year-old fully active, asymptomatic man suffered two episodes of major peripheral arterial embolism within 2 months. Heart disease was ruled out by appropriate investigations. Further diagnostic evaluation (angiography, CAT scan) revealed the extremely rare finding of a "floating mass" in the transverse aortic arch suspected to be the source of embolization. This mass was successfully removed using the technique of hypothermic cardiocirculatory arrest. The histological diagnosis was an aged intraluminal thrombus and moderate atherosclerosis of the thoracic aorta. For prevention of recurrent arterial embolism in cases without an initially apparent cause and site of origin, a thorough diagnostic, and in a given patient, an aggressive surgical approach for the elimination of the embolic source are advocated.

Evaluation of tumor blood perfusion by dynamic MRI and CT in patients undergoing thermoradiotherapy.

In 18 patients who were treated with combined regional hyperthermia and radiation for recurrent pelvic tumors, blood flow related data were obtained using dynamic computed tomography and dynamic magnetic resonance imaging. The enhancement of contrast material (delta HU) and Gadolinium DTPA (delta SI) over baseline in the early phase (15-30 s) after bolus injection is dependent upon perfusion. With both methods significant differences in global perfusion have been observed between tumor center and tumor periphery. With regard to the mean perfusion values we are able to separate high, medium and low perfused pelvic tumors. Flow rates expressed as delta HU for dynamic CT and delta SI for dynamic MRI show a significant inverse correlation with the achieved steady state temperatures above baseline. Values of enhancement of contrast material higher than 15-35 delta HU or 300-700 delta SI indicate flow rates which were limiting in achieving steady state temperatures higher than 3 degrees C above baseline (core temperature).

[Flow time analysis in sonographic flow measurements: an in vitro measurement for testing their accuracy]. / Die Laufzeitanalyse in der sonographischen Flussmessung: In-vitro-Messung zur Uberprüfung der Wertigkeit.

Flow-time analysis is a new technique for colour coded sonographic flow measurements. The measurements depend on a pattern of ultrasound pulses and have some significant advantages compared with Doppler procedures. The accuracy of the method and possible sources of error have been studied under experimental conditions. Measurements on continuous blood flow showed a correlation of r > 0.99 for duplex sonography and of r > 0.93 for flow-time analysis. For this method, the colour coding parameters must be optimal in order to achieve high accuracy. Under these conditions quantitative measurement of pulsatile flow also becomes possible during colour mode.

[High-resolution 3-D imaging in MR tomographic knee joint diagnosis. Correlation with arthroscopy]. / Hochauflösende 3-D-Bildgebung in der kernspintomographischen Kniegelenksdiagnostik: Korrelation zur Arthroskopie.

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.

[The quality of disturbed radiation to the ovaries during diagnostic x-ray exminations (author's transl)]. / Die Qualität der Störstrahlung im Ovarbereich bei röntgendiagnostischen Untersuchungen

Dose measurements and analysis of disturbed spectra have shown that protection of the ovaries against disturbed radiation is worth while, although its effectiveness decreases with higher tube voltages. Increasing tube voltage increases disturbed radiation to the ovaries; the quality of the disturbed radiation is largely independent of the amount of filtration.

[Encephalotomography and computer tomography for abnormalities of the sella (author's transl)]. / Enzephalotomographie und computertomographische Untersuchungen bei Sellaprozessen.

Seventy-four patients with tumors in the sellar region were examined by means of encephalotomography and axial computerised tomography. In nearly all cases, the localisation and expansion of tumors could be exactly determined by encephalotomography. In addition, a graduation according to the degree of hypothalamic compression was possible. In cases of density differences between tumor and brain tissue and contrast enhancement more information of the inner structure of a tumor (cystic or solid) could be obtained by computerised tomography. But in cases of missing density differences or/and contrast enhancement tumor diagnosis is easier by encephalotomography because of the high efficiency of encephalotomography. The indication for the form of operative treatment, transsphenoidal or transcranial, depends on the exact knowledge of tumor growth, especially of the degree of hypothalamic compression. Therefore, in all uncertain computerised diagnosis encephalotomography has to be undertained.

[Digital luminescence radiography (DLR) for skeletal diagnosis in traumatology]. / Digitale Lumineszenzradiographie (DLR) zur Skelettdiagnostik in der Traumatologie.

170 patients who had suffered trauma to bones or soft tissues were examined by a digital and a conventional film/screen technique. In addition to "standard" and edge-enhanced images, post-processing was carried out and compared with conventional radiographs. Four radiologists and two surgeons evaluated the compacta, spongiosa, soft tissues, fractures and osteo-synthetic materials as shown on the two systems. The "standard" digital images are inferior to film images, but edge-enhanced images showed definite advantages for demonstrating soft tissues. Evaluation of osteo-synthetic material is limited by the creation of artifacts. Recognition of detail can be significantly improved by using post-processing with optimized parameters.

[Glucagon as an adjuvant to infusion cholecysto-cholangiography]. / Glukagon als Adjuvans zur Infusions-cholezystcholangiographie.

The effect of glucagon on the results of intravenous cholangio-cholecystography (IVC) was studied in a randomised trial on 246 patients. The injection of 1 mg. glucagon increased the speed of contrast excretion from the liver. This led to a significantly quicker demonstration of the gallbladder, with a tendency to more rapid filling of the biliary ducts. In patients with hyperbilirubinaemia there were somewhat fewer negative cholangiograms and significantly fewer negative cholecystograms. Considering the patients as a whole, the use of glucagon has the advantage of reducing the time taken for the examination and of a reduction of negative IVCs. Since glucagon has practically no side effects, our experience suggests that it can be recommended as an adjuvant to IVC. Improvements in IVCs are particularly significant since they are now only used for special indications.

[Are high-intensifying film-screen combinations suitable for the detection of fine interstitial lung changes? The results of a ROC study with an anthropomorphic thorax phantom]. / Sind hochverstärkende Film-Folien-Kombinationen zur Detektion feiner interstitieller Lungenveränderungen geeignet? Ergebnisse einer ROC-Studie am anthropomorphen Thoraxphantom.

Exposures of an anthropomorphic thorax phantom in posteroanterior projection were made using a focus-film distance of 200 cm and 125 kV with film-screen combinations in class 200 (Curix RP 1L/MR 200) and class 400 (Curix ST-L/Regular). Pathomorphological structures of the lung parenchyma of fine nodular, linear and reticular types were simulated by suitable materials. A ROC analysis including a t-test showed no significant difference in the evaluation of these structural details (p > 0.05). In order to describe image quality for the two film-screen systems, density curves, sigma D-curves and modulation transfer function (MTF) were determined. The only demonstrable difference was reduced MTF of 10-15% for the higher intensification film-screen combination with a resulting poorer resolution of 3.7 l/mm (for the 400 system) compared with 4.3 l/mm for the 200 system.

Radiological aspects of arteriosclerosis: follow-up study of 588 patients in two different groups.

The authors retrospectively compared two groups of patients who had undergone angiography over a twenty-one-year period. The first group consisted of 348 patients who had angiography in the years 1965-1967. The second group was made up of 222 patients who had had angioplasty in the years 1975-1986. Special risk factors such as diabetes and nicotine abuse were singled out together with localization of lesions and gender distribution.

Changes of soft-tissue water examined with magnetic resonance and electrical impedance tomography: an in vivo experiment.

The purpose of this study was the examination of short-term changes in soft-tissue water under in vivo conditions. In 12 healthy volunteers the water distribution of a selected slice of the lower limb was examined after change of position and rapid infusion of 0.9% saline solution. Two methods were used for data acquisition: magnetic resonance imaging (MRI) (Repetition Time (TR) = 1600 msec, Inversion Time (TI) = 300 msec, Echo Time (TE) = 22 msec) and electrical impedance tomography (EIT). In orthostatic equilibrium all 12 volunteers demonstrated changes of MR signal intensity and resistivity in the range of 12% and 7%, respectively. After infusion, mean changes of signal intensity and resistivity were 7% and 4%, respectively. The overall correlation of MRI and EIT was -0.96 (p < 0.001). Results indicate that inversion recovery sequences are a sensitive method of detecting in vivo changes of water distribution in selected areas of the body.

Angioplasty of renal arteries: a report of ten year's experience.

Report of PTA of renal arteries in 288 patients. Primary results show good to optimal dilatation of the arteries (60.6% to 78.6%). One third of all cases achieved optimal blood pressures. In about 40% antihypertensive drugs had to be administered, in about 30% blood pressure remained unchanged although PTA was effective. PTA of renal arteries is the best method of treating renal hypertension, also because of the low rate of complications.

MR relaxometry: estimating overhydration in renal failure.

An MR method is described for estimating overhydration in patients suffering from renal failure. In 29 healthy volunteers, the fat content of a selected slice of the lower limb was correlated to the overall T1-relaxation time (r = -0.97, p < 0.000001). When compared with the normal T1 of the voluntary group, delta T1 was calculated having regard to the individual fat content in 74 MR studies of 22 overhydrated patients. MR results were correlated with the difference between clinically estimated dry and the actual body weight (r = 0.6, p < 0.000001). In an intraindividual follow-up (11 studies) MRI was shown to provide good correlation to the actual body weight (r = 0.9, p < 0.0005) and fluid balance (r = 0.87, p < 0.001).

Epidural abscess following frontal sinusitis--demonstration of communication by epidural contrast medium and coronal computerized tomography.

A case of epidural abscess following sinusitis is presented with rhinorrhoea after irrigation of the abscess cavity postoperatively. Coronal computerized tomography and instillation of contrast medium through the catheter showed communication between epidural space and left frontal sinus.

[Renovascular hypertension--diagnosis and therapeutic possibilities]. / Renovaskuläre Hypertonie--Diagnostik und therapeutische Möglichkeiten.

The causes of renal vascular hypertension are outlined. These are guided by the influence on the renin-angiotensin mechanism. The so-called essential hypertension is not infrequently caused by an early nephrosclerosis, which can be diagnosed very early through electrone microscopy. Renal artery stenosis, caused by fibrodysplasia or arteriosclerosis represents a special case of renal vascular hypertension which can be treated effectively by balloon catheter dilatation. The results in 240 patients are presented where these therapeutic principles were applied.

[Renal tumor diagnosis with ultrasound and CT]. / Renale Tumordiagnostik mit Ultraschall und CT.

The use of sonography and computer tomography has resulted in a marked change in the diagnosis of renal space occupying lesions. The value of these diagnostic tests is analyzed mainly in the diagnosis of solid kidney tumors. The possibilities and limitations are analyzed and the addition of further diagnostic procedures such as fine needle puncture and operative exploration are considered. A proper diagnostic work-up is outlined.

[Color velocity imaging for diagnosis in kidney transplants. Methods for interpretation of color coding]. / "Color velocity imaging" in der Diagnostik von Nierentransplantaten. Methoden zur Interpretation der Farbkodierung.

Colour velocity imaging is a new technique in the field of colour-coded sonographic flow measurement. It measures blood flow directly by analysing ultrasound pulses' running time and has advantages over colour Doppler systems. Colour velocity imaging's colour code detects changes in arterial blood flow. Therefore it can be used in the diagnosis of kidney allografts in the same way as duplex ultrasound. Using the presented methods of colour interpretation, sensitivity of 66.6-100% and specificity of 72.7-91.7% are attained. Thus colour velocity imaging combines the attributes of duplex ultrasound and colour Doppler ultrasound.