80-kVp CT Using Iterative Reconstruction in Image Space Algorithm for the Detection of Hypervascular Hepatocellular Carcinoma: Phantom and Initial Clinical Experience.
10.3348/kjr.2012.13.2.152
- Author:
Saebeom HUR
1
;
Jeong Min LEE
;
Soo Jin KIM
;
Ji Hoon PARK
;
Joon Koo HAN
;
Byung Ihn CHOI
Author Information
1. Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 110-744, Korea. jmsh@snu.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Hepatocellular carcinoma;
Low tube voltage;
Iterative reconstruction;
80-kVp;
Computed tomography;
Image quality
- MeSH:
*Algorithms;
Analysis of Variance;
Carcinoma, Hepatocellular/*blood supply/*radiography;
Contrast Media/diagnostic use;
Female;
Humans;
Iohexol/analogs & derivatives/diagnostic use;
Liver Neoplasms/*blood supply/*radiography;
Male;
Middle Aged;
Phantoms, Imaging;
Radiographic Image Interpretation, Computer-Assisted/*methods;
Regression Analysis;
Retrospective Studies;
Tomography, X-Ray Computed/*methods
- From:Korean Journal of Radiology
2012;13(2):152-164
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To investigate whether the low-tube-voltage (80-kVp), intermediate-tube-current (340-mAs) MDCT using the Iterative Reconstruction in Image Space (IRIS) algorithm improves lesion-to-liver contrast at reduced radiation dosage while maintaining acceptable image noise in the detection of hepatocellular carcinomas (HCC) in thin (mean body mass index, 24 +/- 0.4 kg/m2) adults. SUBJECTS AND METHODS: A phantom simulating the liver with HCC was scanned at 50-400 mAs for 80, 100, 120 and 140-kVp. In addition, fifty patients with HCC who underwent multiphasic liver CT using dual-energy (80-kVp and 140-kVp) arterial scans were enrolled. Virtual 120-kVP scans (protocol A) and 80-kVp scans (protocol B) of the late arterial phase were reconstructed with filtered back-projection (FBP), while corresponding 80-kVp scans were reconstructed with IRIS (protocol C). Contrast-to-noise ratio (CNR) of HCCs and abdominal organs were assessed quantitatively, whereas lesion conspicuity, image noise, and overall image quality were assessed qualitatively. RESULTS: IRIS effectively reduced image noise, and yielded 29% higher CNR than the FBP at equivalent tube voltage and current in the phantom study. In the quantitative patient study, protocol C helped improve CNR by 51% and 172% than protocols A and B (p < 0.001), respectively, at equivalent radiation dosage. In the qualitative study, protocol C acquired the highest score for lesion conspicuity albeit with an inferior score to protocol A for overall image quality (p < 0.001). Mean effective dose was 2.63-mSv with protocol A and 1.12-mSv with protocols B and C. CONCLUSION: CT using the low-tube-voltage, intermediate-tube-current and IRIS help improve lesion-to-liver CNR of HCC in thin adults during the arterial phase at a lower radiation dose when compared with the standard technique using 120-kVp and FBP.
