CT Enterography at 80 kVp With Adaptive Statistical Iterative Reconstruction Versus at 120 kVp With Standard Reconstruction: Image Quality, Diagnostic Adequacy, and Dose Reduction
- 1 May 2012
- journal article
- research article
- Published by American Roentgen Ray Society in American Journal of Roentgenology
- Vol. 198 (5), 1084-1092
- https://doi.org/10.2214/ajr.11.6597
Abstract
OBJECTIVE. The objective of our study was to evaluate the image quality and diagnostic adequacy of the following two CT enterography protocols in patients weighing less than 160 lb (72 kg): 80-kVp imaging with the adaptive statistical iterative reconstruction (ASIR) in comparison with 120-kVp imaging with the filtered back projection reconstruction. MATERIALS AND METHODS. We retrospectively reviewed 133 CT enterography examinations of 127 patients weighing less than 160 lb, 64 80-kVp examinations, and 69 120-kVp examinations. Image quality for evaluation of the bowel wall, mesenteric vessels, and hepatic parenchyma and the overall image quality were graded on a scale of 1–5 (1 = poor, 2 = acceptable, 3 = good, 4 = very good, 5 = excellent). Diagnostic accuracy for the detection of inflammatory bowel disease was evaluated. The volume CT dose index (CTDIvol) was recorded and effective dose was calculated from scanner-generated dose-length product. RESULTS. There was a statistically significant decrease in the mean image quality scores for 80-kVp examinations compared with 120-kVp examinations for evaluation of the bowel wall (3.19 vs 3.70, respectively) and liver (3.12 vs 3.81) and for overall image quality (3.23 vs 3.68), but there was no significant decrease in score for evaluation of the mesenteric vessels (3.63 vs 3.67). None of the 80-kVp examinations was graded as poor, and all were considered to be of acceptable quality. Both techniques had comparable diagnostic accuracy for the detection of inflammatory bowel disease. Interobserver agreement was fair to moderate for qualitative image grading and was substantial for the detection of features of inflammatory bowel disease. The mean CTDIvol and effective dose for the 80-kVp examinations were 6.15 mGy and 4.60 mSv, respectively, and for the 120-kVp examinations, 20.79 mGy and 15.81 mSv. CONCLUSION. In patients weighing less than 160 lb, CT enterography examinations at 80 kVp with 30% ASIR produce diagnostically acceptable image quality with an average CTDIvol of 6.15 mGy and an average effective dose of 4.60 mSv.Keywords
This publication has 35 references indexed in Scilit:
- Impact of new technologies on dose reduction in CTEuropean Journal of Radiology, 2010
- Optimization of kVp and mAs for Pediatric Low-Dose Simulated Abdominal CT: Is It Best to Base Parameter Selection on Object Circumference?American Journal of Roentgenology, 2010
- Detection of Pancreatic Tumors, Image Quality, and Radiation Dose during the Pancreatic Parenchymal Phase: Effect of a Low-Tube-Voltage, High-Tube-Current CT Technique—Preliminary ResultsRadiology, 2010
- Low-Dose MDCT Urography: Feasibility Study of Low-Tube-Voltage Technique and Adaptive Noise Reduction FilterAmerican Journal of Roentgenology, 2009
- Should computed tomography be the modality of choice for imaging Crohn's disease in children? The radiation risk perspectiveGut, 2008
- CT enterography of Crohn’s diseaseAbdominal Radiology, 2008
- Lower Tube Voltage Reduces Contrast Material and Radiation Doses on 16-MDCT AortographyAmerican Journal of Roentgenology, 2006
- CT Enterography as a Diagnostic Tool in Evaluating Small Bowel Disorders: Review of Clinical Experience with over 700 CasesRadioGraphics, 2006
- Using the K-edge to Improve Contrast Conspicuity and to Lower Radiation Dose With a 16-MDCTJournal of Computer Assisted Tomography, 2006
- Techniques and Applications of Automatic Tube Current Modulation for CTRadiology, 2004