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) All Versions of this Article: 2251010930v1 225/1/83    most recent 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 Birnbaum, B. A. Articles by Babb, J. S. Search for Related Content PubMed PubMed Citation Articles by Birnbaum, B. A. Articles by Babb, J. S.

Renal Cyst Pseudoenhancement: Evaluation with an Anthropomorphic Body CT Phantom¹

¹ From the Department of Radiology, New York University Medical Center, 560 First Ave, New York, NY 10016 (B.A.B., J.E.J., J.S.B.); Department of Radiology, Scottsdale Memorial Hospitals, Ariz (D.D.M.); and Department of Radiology, University of Pennsylvania Medical Center, Philadelphia (D.P.C.). From the 2000 RSNA scientific assembly. Received May 15, 2001; revision requested June 26; final revision received May 29, 2002; accepted June 5. Address correspondence to B.A.B. (e-mail: bernard.birnbaum@med.nyu.edu).

PURPOSE: To determine the effects of cyst diameter and location (intrarenal, exophytic), renal attenuation, section collimation, and computed tomographic (CT) interscanner variability on renal cyst pseudoenhancement in a phantom model.

MATERIALS AND METHODS: A customized anthropomorphic phantom was designed to accept 40-, 140-, and 240-HU renal inserts containing intrarenal and exophytic 7-, 10-, and 15-mm cysts. Each phantom and insert were scanned with five different helical CT scanners by using 1.0–1.5-mm, 2.50–3.75-mm, 5.0-mm, 7.0–8.0-mm, and 10.0-mm section collimation. Means and SDs of CT number measurements were obtained for each cyst within each variably "enhanced" renal insert. Mixed-model analysis of variance accommodating heteroscedasticity of data was used to assess the effect of scanner type, section collimation, and cyst diameter on cyst attenuation.

RESULTS: Pseudoenhancement (range, 10.3–28.3 HU), observed by using effective section collimation equal to or less than 50% of cyst diameter, occurred in 34 (38%) of 90 intrarenal cyst measurements. Pseudoenhancement was observed with all five CT scanners, though the magnitude of the effect was nonuniform. Significant interactions were noted between renal cyst diameter, background renal attenuation, and CT scanner type in terms of their effects on cyst attenuation. No appreciable pseudoenhancement was observed with exophytic cysts.

CONCLUSION: Pseudoenhancement is maximal when small (1.5-cm) intrarenal cysts are scanned during maximal levels of renal parenchymal enhancement. The magnitude of this effect varies with scanner type but may be large enough to prevent accurate lesion characterization, despite use of a thin-section helical CT data acquisition technique.

© RSNA, 2002

Index terms: Computed tomography (CT), experimental studies, 81.12111, 81.12112 • Experimental study • Kidney, CT, 81.12111, 81.12112 • Kidney, cysts, 81.3111 • Phantoms

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]

				G. M. Israel and M. A. Bosniak Pitfalls in Renal Mass Evaluation and How to Avoid Them RadioGraphics, September 1, 2008; 28(5): 1325 - 1338. [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]

				S. G. Silverman, K. J. Mortele, K. Tuncali, M. Jinzaki, and E. S. Cibas Hyperattenuating Renal Masses: Etiologies, Pathogenesis, and Imaging Evaluation RadioGraphics, July 1, 2007; 27(4): 1131 - 1143. [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]

				M. E. Zalis, J. J. Perumpillichira, J. Y. Kim, C. Del Frate, C. Magee, and P. F. Hahn Polyp Size at CT Colonography after Electronic Subtraction Cleansing in an Anthropomorphic Colon Phantom Radiology, July 1, 2005; 236(1): 118 - 124. [Abstract] [Full Text] [PDF]

				G. A. Krakora, F. V. Coakley, G. Williams, B. M. Yeh, R. S. Breiman, and A. Qayyum Small Hypoattenuating Hepatic Lesions at Contrast-enhanced CT: Prognostic Importance in Patients with Breast Cancer Radiology, December 1, 2004; 233(3): 667 - 673. [Abstract] [Full Text] [PDF]

				E. M. Hecht, G. M. Israel, G. A. Krinsky, W. Y. Hahn, D. C. Kim, I. Belitskaya-Levy, and V. S. Lee Renal Masses: Quantitative Analysis of Enhancement with Signal Intensity Measurements versus Qualitative Analysis of Enhancement with Image Subtraction for Diagnosing Malignancy at MR Imaging Radiology, August 1, 2004; 232(2): 373 - 378. [Abstract] [Full Text] [PDF]

				G. M. Israel, N. Hindman, and M. A. Bosniak Evaluation of Cystic Renal Masses: Comparison of CT and MR Imaging by Using the Bosniak Classification System Radiology, May 1, 2004; 231(2): 365 - 371. [Abstract] [Full Text] [PDF]

				M. Suh, F. V. Coakley, A. Qayyum, B. M. Yeh, R. S. Breiman, and Y. Lu Distinction of Renal Cell Carcinomas from High-Attenuation Renal Cysts at Portal Venous Phase Contrast-enhanced CT Radiology, August 1, 2003; 228(2): 330 - 334. [Abstract] [Full Text] [PDF]