Unenhanced helical CT following excretory urography in the diagnosis of upper urinary tract disease: a little more cost, a lot more value.

The objective of the study is to evaluate unenhanced CT following intravenous urography (IVU) for the detection of upper urinary tract (UUT) abnormalities, when IVU fails to provide the qualitative diagnosis. Helical CT scan was performed on patients with suspected disorders of UUT, after the completion of IVU for further diagnoses. In total, 124 cases of definite diagnosis and 71 cases of uncertain diagnosis via IVU were collected from 195 patients with suspected UUT disorders. Among the 71 uncertain cases, 65 patients were consent to undergo immediate or delayed CT scan. CT data were transferred to the workstation for postprocessing. Of all the 65 cases, the major CT diagnoses were the following: stone disease (n = 41), urinary tract infections (n = 4), UUT tumors (n = 7), neighboring invasion or metastasis (n = 2), congenital anomalies (n = 2), and compressed stenosis (n = 6). Among all the results, 62 cases were confirmed by surgery, pathology or clinical follow-up, while three cases (4.6%) left were still uncertain. The diagnose accordance rate of IVU + CT achieved to 95.4%. There was significant difference between IVU and IVU + CT in the determinate diagnosis of UUT diseases (chi (2) = 30.4, P < 0.05). In conclusion, IVU + CT provides more valuable information for the localization and qualitative diagnosis of UUT abnormalities. It is recommended as a cost-effective and time-saving complemental means for IVU.