Comparative viewing modalities for CT cystography

Background: To define the speed and accuracy of two different reconstructiv e techniques using computed tomography (CT) cystography for the detection a nd measurement of urinary bladder masses and determine the overall ease of use. Methods: Ten patients scheduled for cystoscopy for the evaluation of hematu ria or bladder masses were studied by means of thin-section CT of the air-d istended bladder. Two techniques were employed by two radiologists to blind ly interpret the data: conventional two-dimensional data with interactive t hree-dimensional problem solving (2D3DPS) and surface-shaded display (SSD) three-dimensional images. The results were compared with the data from cyst oscopy. Results: Twenty-two (100%) of 22 masses detected on cystoscopy were visuali zed using the reconstructive techniques. Both modalities were shown to have high accuracy, but only the 2D3DPS had a sensitivity and specificity of 10 0% for both observers at the patient-level diagnosis. The sensitivities for detecting individual masses for the two observers were 100% and 64% for 2D 3DPS and 64% and 70% for SSD. Conclusion: Both methods used to display the CT data had a high sensitivity and specificity for masses, but only the 2D3DPS had a sensitivity and spec ificity of 100% at the patient-level diagnosis, thus making it a feasible i maging modality for cystography. It was also preferred overall for ease of use, high accuracy, and relative low cost.