[Tissue characterization of the liver using ultrasound attenuation in an animal experiment]. / Zur Gewebecharakterisierung der Leber mittels Ultraschallschwächung im Tierexperiment.

Frequency-dependent attenuation of sound is considered a characteristic parameter of the interaction between sound and tissue and has been studied particularly in the liver via many different techniques. Due to the relatively wide scatter of the measured single values, especially in pathological liver samples, a clinically feasible application of the procedure has not yet been found. In the present paper, the suitability of the frequency-dependent coefficient of sound attenuation for tissue characterization with comparable experimental conditions in vitro was tested in a statistically representative collection of histologically defined tissue specimens of rat liver. Several statistical procedures were used (cluster analysis, discrimination analysis). Normal livers can be usually distinguished from pathological specimens by means of the frequency-dependent coefficient of sound attenuation with only slight scatter of the individual values. Although the latter differ on the average from normal specimens, they diverge considerably in respect of single values resulting in significant differences only in case of extensive tissue damage (cirrhosis). On the basis of tissue classifications in clinical and pathological use, only a rough tissue differentiation is possible. By using additional parameters of the interaction between sound and tissue, sonographic differentiation of pathologically changed tissue my be improved.

[Ultrasound-controlled cutting biopsy for collecting histologic specimens]. / Ultraschallgezielte Schneidbiopsie zur Gewinnung von histologisch auswertbarem Material.

The fine-needle puncture under ultrasound guidance has the disadvantage that the material obtained can only be evaluated by cytology. The cutting biopsy cannula represents a compromise between the fine and the Menghini needle. In this way, small tissue cylinders can be attained. The aim of the present study was to investigate to what extent the sampled specimen could be assessed by cytology or histology. Fine-needle puncture resulted in 22 (69%) out of 32 cases in material suitable for cytology. Cutting biopsy led in 34 out of 36 cases (94%) to specimen valid for histology. Thus, cutting biopsy clearly extends our diagnostic tools. It is not yet clear at present whether procedures with a higher risk - such as the Menghini puncture - can be in part replaced by alternative ones.

[Rational procedures in the differential diagnosis of jaundice]. / Rationales Vorgehen in der Differentialdiagnose des Ikterus.

In jaundice after exclusions of prehepatic and functional hepatogenic hyperbilirubinaemias the sonography should pre-eminently be used as a riskless, economical and qualified investigation method, taking into consideration clinical and laboratory-chemical data. If sonographically the findings of an intrahepatic cholostatis are shown, in therapeutic relevance the histological clarification must follow. Only in unequivocal focal changes of the liver (perhaps thin needle puncture) further investigations are unnecessary. If there are findings of an extrahepatic cholostasis, in a not unequivocal sonographic result or before a surgical intervention further aimed investigations, such as ERCP, PTC and CT, are necessary for the exact clarification of the cause of the obstruction of the bile ducts.

[Results of ultrasound tomography in the diagnosis of liver diseases]. / Ergebnisse der Ultraschalltomographie in der Diagnostik von Lebererkrankungen.

In a prospective study the impact of ultrasound tomography in the recognition and exclusion, respectively, of liver diseases was investigated. 646 patients with a suspected liver disease were sonographed in real-time procedure. The investigator was familiar with the history as well as with clinical and lab findings before the examination was started. The sonography was performed before a laparoscopy, liver blind punktion, scintigraphy, angiography, computerized tomography. The diagnoses were confirmed by sufficient, comparable methods (see above) or operatively; they were supported by a follow-up for one year. While liver cysts, cystic livers, liver abscesses, haematomas, metastases (with a diameter of more than 10-20 mm), stasis liver, cirrhoses with portal hypertension and fatty livers could be diagnosed with a high rate of confidence by sonography, healthy livers and the following disorders could not exactly be separated by ultrasound: acute hepatitis, reactive hepatitis hepatoses, chronically persisting hepatitis, chronic active hepatitis, and livers with a low incorporation of fat.

[Initial results of a combined sonographic and cytologic diagnosis of scintigraphically remarkable thyroid changes using real-time visual puncture]. / Erste Ergebnisse einer kombinierten sonographischen und zytologischen Diagnostik szintigraphisch auffälliger Schilddrüsenveränderungen unter Anwendung der Real-Time-Sichtpunktion.

The combination of sonography and biopsy in the diagnostics of the thyroid gland results in a reliability of 100%. Thus the routine application effective diagnostics and therapy is justified. The course control after emptying of the cyst is simplified, the therapeutic effect of the puncture can be revealed. It can be attracted as evident method which is poor in risk for the confirmation of an indication to operation. This form of examination is possible also then, when no sonographic device with a puncture is at our disposal.