The accuracy of sonographic measurement

Sonographic measurements often give considerable diagnostic significance. However, large discrepancy betweenthe real anatomic sizes and sonographic measurements could cause an incorrect diagnosis. Authors carried out aseries of experiment using a phantom and two scanners and the results are as follows: 1. There is a littledifference in errors between two scanners, and the mesurement does not almost always correspond to the realdistance. 2. The rates of errors of the measurements are almost fixed regardless of the positions of thereflcetors. 3. There is no relationship between the transducer MHZ and error rate. 4. As the error is derived from the scanner electronics it is necessary to calibrate the scanner periodically, and if not calibrated one shouldconsider the error rate of the scanner in the anatomical measurement.

Transposition of inferior vena cava

An incidentally detected transposition of the inferior vena cava in patient with gall bladder carcinoma isreported with discussion of findings of CT scan and review of anomalies of the inferior vena cava. Since anomalousvena cava may simulate any other abnormality such as metastatic disease, it is very important to know anomaly ofthe vena vaca with understanding of its embryological back ground.