[Sonography today: reference values in abdominal ultrasound: aorta, inferior vena cava, kidneys].

OBJECTIVE: Reference values for B-mode abdominal ultrasound are controversially discussed due to the limited data in the literature. A systematic survey of data published so far is presented for the big retroperitoneal vessels and the kidneys.

METHODS: A literature review of reference values in the abdomen from 1970 to 2011 in healthy subjects 18 years of age and older was undertaken. According to the determination of reference intervals for laboratory values, reference values are generally determined using 95 % reference intervals and their associated 90 % confidence intervals. The diameters of the abdominal aorta and the inferior vena cava were evaluated as well as the length, width, thickness, parenchymal thickness and volume of the kidneys.

RESULTS: 61 studies were analysed. Reference values determined for the aorta vary considerably according to age and gender of the probands, measuring position and measuring technique. The upper interval limits of the 95 % reference intervals lie between 17 and 40 mm. The diameter of the inferior vena cava depends on the position of the patient, the measuring site, respiration and the resting heart rate. Normal results up to 27 mm can be encountered. Influencing factors on the size and volume of the kidneys are the side (right/left), age, gender, anthropometric parameters and the ethnic membership of the probands. For central European women, 9 cm - 12.8 cm can be regarded as the normal range of the length of the kidney and for men 9.2 cm - 13.3 cm. For the width of the kidney, interval limits were determined between 3 cm and 7.1 cm, for the thickness between 2.9 cm and 6 cm, for the parenchymal thickness between 1.1 cm and 2.3 cm and for the volume between 59 and 230 mL.

DISCUSSION: Normal values are helpful in delimiting numerous pathological changes in the respective organs.