Acoustic radiation force impulse imaging for non-invasive assessment of liver fibrosis in chronic hepatitis B.

Acoustic radiation force impulse (ARFI) imaging is a novel ultrasound-based elastography method that is integrated in a conventional ultrasound machine. It might provide an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. While previous studies have shown comparable diagnostic accuracy of ARFI to transient elastography in chronic hepatitis C, the aim of the present prospective multicenter study was to evaluate ARFI for the assessment of liver fibrosis in chronic hepatitis B. ARFI imaging involves the mechanical excitation of tissue using short-duration acoustic pulses to generate localized displacements in tissue. The displacements result in shear-wave propagation which is tracked using ultrasonic, correlation-based methods and recorded in m/s. In the present international prospective study, patients infected with chronic hepatitis B received ARFI imaging, blood tests and if available transient elastography. The results were compared to liver biopsy as reference method analysed by a central pathologist. In 92 of 114 patients, a comparison of ARFI with transient elastography was possible. ARFI imaging and transient elastography correlated significantly with histological fibrosis stage. The diagnostic accuracy expressed as areas under ROC curves for ARFI imaging and transient elastography was 0.75 and 0.83 for the diagnosis of significant fibrosis (F ≥ 2), 0.93 and 0.94 for the diagnosis of severe fibrosis (F ≥ 3), and 0.97 and 0.93 for the diagnosis of liver cirrhosis, respectively. No significant difference was found between ARFI and transient elastography. ARFI imaging is a reliable ultrasound-based method for the assessment of advanced stages of liver fibrosis in chronic hepatitis B.

[Artificial intranasal bacterial invasion in the newborn calf. 1. Quantitative assessment of nasal secretion for certain groups of bacteria]. / Untersuchungen zue künstlichen intranasalen Keimbesiedlung beim neugeborenen Kalb. 1. Quantitative Erfassung einzelner Keimgruppen im Nasenschleim

A technique has been developed for quantitative assessment of nasal secretion for the presence of specified groups of bacteria, as a contribution to microbiological treatment of the problem of artificial intranasal bacterial invasion in newborn and nursed calf. Some 10(6) to 10(7) bacteria were recorded from each gram of nasal secretion in calves exposed to natural bacterial invasion. Micrococci and green diplococci were very rare, with only 10(3) to 10(4) or hardly up to 10(5) bacteria per gram of nasal secretion. Streptococci were irregularly found in smaller counts. Bacteria of the coli group went up steeply on the second or not later than the third day of age, and the rise continued to the ninth day. Coliform germs accounted for high or even the highest percentage in total invasion during that period of time.