Elastography of the Liver in Cystic Fibrosis Patients. Diagnostic and Prognostic Aspects

The aim of the study is to find CF patients at risk for cystic fibrosis related liver disease (CFLD). Comparison of ultrasound by two modalities and biochemical markers with histological evaluation of liver biopsy if present.

There are 209 CF patients attending Stockholm Cystic Fibrosis Center (January 2010). All up till 15 years of age are screened for liver disease annually by ultrasound (US) and also by biochemical markers. Ultrasound is performed every third year over 15 years of age in patients without CFLD, while all of them with diagnosed CFLD are continued to be investigated annually. Biochemical markers are controlled at least once every year in all CF patients. Elastography of the liver will be planned together with the investigations of the annual follow up, in an optimal clinical status. If either US or elastography of the liver indicates liver disease or progress of the already existing pathological changes, a liver biopsy will be performed according to routine procedure at Stockholm CF Centre. Also, historical data of liver biopsies and biochemical investigations will be considered in the study. Elastography of the liver will be performed by Fibroscan device, with transducers for children and adults, respectively. Clinical importance Liver US investigations in CF patients have important implications but are difficult to standardize in a routine clinical setting. Elastography may have an advantage in the evaluation of early fibrosis with clinical importance in pursuing diagnostics and intensifying treatment. A significant group (up to 25 %) of CF patients may be helped by this novel method. Including histological data, accuracy of elastography in CF patients may be improved. Further details of the importance of fatty acid status in CF may be elucidated.

Ultrasound by specific wavelength developed for elastography, repeated measures according to the manufacturer's instructions.

Elastographic values given in kPa by Fibroscan. All patients undergo elastographic measurement of the liver and ultrasound of the liver. The grade of fibrosis is to be established by setting the cut-off for cystic fibrosis patients.