TY - JOUR
T1 - Renal cyst pseudoenhancement at multidetector CT
T2 - What are the effects of number of detectors and peak tube voltage?
AU - Wang, Zhen J.
AU - Coakley, Fergus V.
AU - Fu, Yanjun
AU - Joe, Bonnie N.
AU - Prevrhal, Sven
AU - Landeras, Luis A.
AU - Webb, Emma M.
AU - Yeh, Benjamin M.
PY - 2008/9
Y1 - 2008/9
N2 - Purpose: To determine the effect of the number of detectors and peak tube voltage on renal cyst pseudoenhancement in a phantom model. Materials and Methods: This study on computed tomographic (CT) phantoms did not require institutional review board approval. The renal compartments of a CT phantom were filled with iodinated contrast material diluted to attain attenuations of 40, 140, and 240 HU. Saline-filled cylinders simulating cysts of varying diameters (range, 0.7-3.0 cm) were serially suspended in the renal compartments and scanned at 80, 90, 100, 120, and 140 kVp in 16-detector (n = 3) and 64-detector (n = 2) CT scanners. Generalized estimating equations were used to determine predictors of cyst pseudoenhancement (defined as a >10 HU increase in cyst attenuation when the background renal attenuation increased from 40 to 140 or 240 HU). Results: Pseudoenhancement was seen with higher frequency (59 [61%] of 96 cysts vs 52 [39%] of 132 cysts, P < .05) and magnitude (17 vs 13 HU, P < .005) with 64- rather than with 16-detector scanners. Pseudoenhancement was also seen with higher frequency (25 [42%] of 60 cysts vs 11 [18%] of 60 cysts, P < .005) and magnitude (18 vs 13 HU, P < .05) at 140 kVp than at 80 or 90 kVp. Cyst pseudoenhancement increased with higher background renal enhancement (P < .005) and smaller cyst diameter (P < .05). The number of detectors, peak tube voltage, renal parenchymal enhancement level, and cyst diameter were independent predictors of cyst pseudoenhancement. Conclusion: Lower tube voltage settings may be useful when accurate differentiation between small renal cysts and solid masses is critical, particularly for 64-detector CT scanners.
AB - Purpose: To determine the effect of the number of detectors and peak tube voltage on renal cyst pseudoenhancement in a phantom model. Materials and Methods: This study on computed tomographic (CT) phantoms did not require institutional review board approval. The renal compartments of a CT phantom were filled with iodinated contrast material diluted to attain attenuations of 40, 140, and 240 HU. Saline-filled cylinders simulating cysts of varying diameters (range, 0.7-3.0 cm) were serially suspended in the renal compartments and scanned at 80, 90, 100, 120, and 140 kVp in 16-detector (n = 3) and 64-detector (n = 2) CT scanners. Generalized estimating equations were used to determine predictors of cyst pseudoenhancement (defined as a >10 HU increase in cyst attenuation when the background renal attenuation increased from 40 to 140 or 240 HU). Results: Pseudoenhancement was seen with higher frequency (59 [61%] of 96 cysts vs 52 [39%] of 132 cysts, P < .05) and magnitude (17 vs 13 HU, P < .005) with 64- rather than with 16-detector scanners. Pseudoenhancement was also seen with higher frequency (25 [42%] of 60 cysts vs 11 [18%] of 60 cysts, P < .005) and magnitude (18 vs 13 HU, P < .05) at 140 kVp than at 80 or 90 kVp. Cyst pseudoenhancement increased with higher background renal enhancement (P < .005) and smaller cyst diameter (P < .05). The number of detectors, peak tube voltage, renal parenchymal enhancement level, and cyst diameter were independent predictors of cyst pseudoenhancement. Conclusion: Lower tube voltage settings may be useful when accurate differentiation between small renal cysts and solid masses is critical, particularly for 64-detector CT scanners.
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U2 - 10.1148/radiol.2482071583
DO - 10.1148/radiol.2482071583
M3 - Article
C2 - 18632527
AN - SCOPUS:51549117364
SN - 0033-8419
VL - 248
SP - 910
EP - 916
JO - RADIOLOGY
JF - RADIOLOGY
IS - 3
ER -