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Table 1. Diagnostic Accuracy in the Detection of Urinary Stone Between CT Urography (CTU) and Intravenous Urography (IVU) (n=34) CTU Urinary stone (+) Urinary stone ( ) (n=27) (n=7) IVU Urinary stone (+) (n=15) 15 0 Urinary stone ( ) (n=19) 12 7 A B C Fig. 1. Both ureter and calyceal stones: A. On KUB, two radiopaque densities are seen in the both paravertebral regions. And a few radiopacities are noted in both renal regions. B. Hydronephrosis is noted in right side and delayed excretion of contrast is noted in left side on IVU. C. On VR image at excretory phase (at 5 minutes), both hydronephroses with both ureter stones are seen. Both calyceal stones are masked by contrast. 608
A B C Fig. 2. Left mid-ureter stone without hydronephrosis. A. On IVU, there is no evidence of urinary stone or hydronephrosis. B. On MIP image (at 2 minutes), a small ureter stone is seen in left side. C. However, the left ureter stone is obscured on the delayed CTU. 609
Fig. 3. Transitional cell carcinoma involving right distal ureter. A. On 90 minutes IVU after intravenous contrast injection, right urinary tract is not seen, which is suggestive of obstructive lesion on the right side. B. Coronal reformatted images at the delayed phase shows the wall thickening and luminal narrowing of right ureter (arrow). A B 610
1. Joffe SA, Servaes S, Okon S, Horowitz M. Multi-detector row CT urography in the evaluation of hematuria. Radiographics 2003;23:1441-1456 2. Tamm EP, Silverman PM, Shuman WP. Evaluation of the patient with flank pain and possible ureteral calculus. Radiology 2003;228:319-329 3. Kawamoto S, Horton KM, Fishman EK. Computed tomography urography with 16-channel multidetector computed tomography: a pictorial review. J Comput Assist Tomogr 2004;28:581-587 4. Akbar SA, Mortele KJ, Baeyens K, Kekelidze M, Silverman SG. Multidetector CT urography: techniques, clinical applications, and pitfalls. Semin Ultrasound CT MR 2004;25:41-54 5. Tack D, Sourtzis S, Delpierre I, de Maertelaer V, Gevenois PA. Low-dose unenhanced multidetector CT of patients with suspect- renal colic. AJR Am J Reontgenol 2003;180:305-311 ed 6. Lang EK, Macchia RJ, Thomas R, Watson RA, Marberger M, Lechner G, et al. Improved detection of renal pathologic features in multiphasic helical CT compared with IVU in patients presenting with microscopic hematuria. Urology 2003;61:528-532 7. Nawfel RD, Judy PF, Schleipman AR, Silverman SG. Patient radiation dose at CT urography and conventional urography. Radiology 2004;232:126-132 611
Comparison of CT Urography and Intravenous Urography in Patients with Hematuria 1 Guen Young Lee, M.D., Byung Chul Kang, M.D., Ji Young Hwang, M.D. 1 Department of Diagnostic Radiology, Ewha Womans University College of Medicine Purpose: We wanted to compare CT urography (CTU) with using multi-detector row CT (MDCT) and intravenous urography (IVU) for diagnosing the causes of hematuria. Materials and Methods: From January 2003 to March 2004, IVU and CTU were obtained in 48 patients. We evaluated the causes of hematuria in 34 of 48 patients. The IVU images were obtained by the conventional method. The CTU images were routinely obtained before intravenous contrast injection, and at 2 and 5 minutes after intravenous contrast injection. In case of delayed excretion of contrast by the kidneys, the delayed CT scans were obtained at 120 minutes after contrast injection. All the CT images, including the axial and 3D coronal reformatted CTUs with using software as well as conventional IVU images, were reviewed by two radiologists working in consensus. We decided if urinary stone existed or not and we looked for the indirect signs such as hydronephrosis or delayed excretion, etc. We also observed if it was possible to determine the mass, ureteral stricture and enhancement of the ureteral wall, etc. We calculated sensitivity, specificity, positive predictive value and negative predictive value for each modality to diagnose urinary stone. We compared the detection rate according to the phases of CTU. Results: We confirmed the presence of urinary tract stones in 27 of 34 patients who had undergone both IVU and CTU. We diagnosed ureteritis in 1, transitional cell carcinoma in 5 and acute pyelonephritis in 1 of the remaining 7 patients. The urinary stones were detected in fifteen patients on both IVU and CTU (15/27, 55.6%). We detected the urinary stones on CTU, but not IVU, in twelve patients (12/27, 44.5%). The sensitivity to detect the urinary stones was 100% (27/27) on CTU and 55.6% (12/27) on IVU respectively. The specificity was 100% (7/7) on IVU and CTU, respectively. The positive predictive value was 100% (15/15) on IVU and 100% (27/27) on CTU, respectively. The negative predictive value was 36.8% (7/19) on IVU and 100% (7/7) on CTU. Precontrast CTU demonstrated the urinary stones in all 27 patients (100%, 27/27). On the other hands, urinary stones were detected in 19 patients (19/27, 70.4%) and 8 patients (8/27, 29.6%) at 2 and 5 minutes on CTU, respectively. Conclusion: CTU is superior to IVU to diagnose the causes of hematuria such as urinary tract stone or extrarenal lesion. Precontrast CTU is the most useful modality for the detection of the urinary tract stone of the other enhanced CTUs. Index words : Hematuria Genitourinary system, calculi Urography Computed tomography (CT), comparative studies Address reprint requests to : Byung Chul Kang, M.D., Department of Diagnostic Radiology, Ewha Womans University MokDong Hospital, 911-1, Mok-dong, Yangcheon-gu, Seoul 158-710, Korea. Tel. 82-2-2650-5173 Fax. 82-2-2650-5302 E-mail: bckang@ewha.ac.kr 612