HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bae, K. T. Articles by Bennett, H. F. Search for Related Content PubMed PubMed Citation Articles by Bae, K. T. Articles by Bennett, H. F.

Renal Cysts: Is Attenuation Artifactually Increased on Contrast-enhanced CT Images?¹

¹ From the Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, St Louis, MO 63110. From the 1999 RSNA scientific assembly. Received September 14, 1999; revision requested October 8; revision received November 16; accepted December 7. Address correspondence to K.T.B. (e-mail: baet@mir.wustl.edu).

PURPOSE: To determine if the attenuation values of simple renal cysts are artifactually increased on contrast material–enhanced, clinically acquired spiral computed tomographic (CT) images.

MATERIALS AND METHODS: Dual-phase renal spiral CT studies (5-mm collimation; pitch, 1.0) were retrospectively analyzed in 24 consecutive patients who had ultrasonographic (US) documentation of simple renal cysts. Forty-eight cysts were identified. The attenuation values of each cyst were measured on nonenhanced, cortical phase, and nephrographic phase images. The size and the location of each cyst in relation to the renal parenchyma were also recorded.

RESULTS: The cysts were 0.6–10.8 cm in diameter (mean, 2.6 cm; SD, 2.0). The mean attenuation change in the cysts from nonenhanced to contrast-enhanced images was statistically significant in a comparison of cortical phase and nephrographic phase images (P < .01): +1.8 HU (SD, 3.8) for cortical phase and +3.6 HU (SD, 5.6) for nephrographic phase images. Renal cysts 1.0 cm or smaller showed a higher attenuation increase (mean, +4.0 HU for cortical phase and +11.0 HU for nephrographic phase). None of the renal cysts larger than 1.0 cm demonstrated an increase greater than 10 HU (mean, +1.4 HU for cortical phase and +2.3 HU for nephrographic phase). Intraparenchymal cysts showed higher mean attenuation changes than the exophytic cysts.

CONCLUSION: Attenuation values in the renal cysts increased artifactually on contrast-enhanced images, but this pseudoenhancement was not substantial and was less than 10 HU when the cyst was larger than 1.0 cm in diameter.

Index terms: Computed tomography (CT), contrast enhancement, 81.12112 • Computed tomography (CT), helical, 81.12115 • Kidney, CT, 81.12111, 81.12112 • Kidney, cysts, 81.3111

This article has been cited by other articles:

				Z. J. Wang, F. V. Coakley, Y. Fu, B. N. Joe, S. Prevrhal, L. A. Landeras, E. M. Webb, and B. M. Yeh Renal Cyst Pseudoenhancement at Multidetector CT: What Are the Effects of Number of Detectors and Peak Tube Voltage? Radiology, September 1, 2008; 248(3): 910 - 916. [Abstract] [Full Text] [PDF]

				B. A. Birnbaum, N. Hindman, J. Lee, and J. S. Babb Renal Cyst Pseudoenhancement: Influence of Multidetector CT Reconstruction Algorithm and Scanner Type in Phantom Model Radiology, September 1, 2007; 244(3): 767 - 775. [Abstract] [Full Text] [PDF]

				E. M. Remer, G. A. Motta-Ramirez, L. B. Shepardson, A. H. Hamrahian, and B. R. Herts CT histogram analysis in pathologically proven adrenal masses. Am. J. Roentgenol., July 1, 2006; 187(1): 191 - 196. [Abstract] [Full Text] [PDF]

				G. M. Israel and M. A. Bosniak How I Do It: Evaluating Renal Masses Radiology, August 1, 2005; 236(2): 441 - 450. [Abstract] [Full Text] [PDF]

				E. P. Chung, B. R. Herts, G. Linnell, A. C. Novick, N. Obuchowski, D. M. Coll, and M. E. Baker Analysis of Changes in Attenuation of Proven Renal Cysts on Different Scanning Phases of Triphasic MDCT Am. J. Roentgenol., February 1, 2004; 182(2): 405 - 410. [Abstract] [Full Text] [PDF]

				K. T. Bae, P. Fuangtharnthip, S. R. Prasad, B. N. Joe, and J. P. Heiken Adrenal Masses: CT Characterization with Histogram Analysis Method Radiology, September 1, 2003; 228(3): 735 - 742. [Abstract] [Full Text] [PDF]

				C. Abdulla, M. K. Kalra, S. Saini, M. M. Maher, A. Ahmad, E. Halpern, and S. G. Silverman Pseudoenhancement of Simulated Renal Cysts in a Phantom Using Different Multidetector CT Scanners Am. J. Roentgenol., December 1, 2002; 179(6): 1473 - 1476. [Abstract] [Full Text] [PDF]

				B. A. Birnbaum, D. D. Maki, D. P. Chakraborty, J. E. Jacobs, and J. S. Babb Renal Cyst Pseudoenhancement: Evaluation with an Anthropomorphic Body CT Phantom Radiology, October 1, 2002; 225(1): 83 - 90. [Abstract] [Full Text] [PDF]

				V. B. Ho, S. F. Allen, M. N. Hood, and P. L. Choyke Renal Masses: Quantitative Assessment of Enhancement with Dynamic MR Imaging Radiology, September 1, 2002; 224(3): 695 - 700. [Abstract] [Full Text] [PDF]