Can sinogram-affirmed iterative reconstruction improve the detection of small hypervascular liver nodules with dual-energy CT?
OBJECTIVE
To optimize a dual-energy computed tomographic protocol with sinogram-affirmed iterative reconstruction algorithms for improving small nodules detection.


METHODS
The raw data of a dual-energy computed tomographic arterial acquisition of a cirrhotic patient were reconstructed with a standard filtered back projection (B20f) and 3 iterative (I26, I30, I31) kernels with different strength (S3-S5). The 80-kilovolt (peak) (kVp) and the linear blended (DE_0.5) images (80-140 kVp) were analyzed. For each series, 8-subcentimeter low-contrast lesions were simulated within the liver. Four radiologists performed a detectability test and rated the image quality (5-point scales) in all images.


RESULTS
The sensitivity increased from 31% (B20f) to 87.5% with sinogram-affirmed iterative reconstruction S5 kernels without a difference between 80-kVp and DE_0.5 series (W test, P = 0.062). The highest image quality rating was 3.8 (B20 DE_0.5), without difference from DE_0.5 I30-S5 and I26-S3.


CONCLUSIONS
Iterative reconstructions increase the sensitivity for detecting abdominal lesions, even in the 80-kVp series. The kernel I30-S5 was considered the best.
From the *Department of Radiology, University of Brescia, Brescia, Italy; and †Medical Physics Unit, Imaging Department, Spedali Civili di Brescia, Brescia, Italy.
Luca
L
Facchetti
Luca
L
Berta
Lorella
L
Mascaro
Roberto
R
Maroldi
D000328:Adult; D000368:Aged; D000465:Algorithms; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000150:complications / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*