Improvement of image quality at low-radiation dose and low-contrast material dose abdominal CT in patients with cirrhosis: intraindividual comparison of low tube voltage with iterative reconstruction algorithm and standard tube voltage.

Abstract

OBJECTIVE:

To intraindividually compare a low-tube voltage, low-contrast material dose computed tomography (CT) reconstructed with iterative reconstruction (IR) algorithm at standard tube voltage reconstructed with filtered back projection (FBP) and standard-contrast material dose during liver dynamic CT.

MATERIALS AND METHODS:

Twenty-five patients with liver cirrhosis underwent 64-section multidetector CT. One hundred twenty kilovolt (peak) (kV[p]) with standard contrast material dose of 600 mg of iodine per kilogram (protocol A) and 80 kV(p) with low-contrast material dose of 450 mg of iodine per kilogram (protocol B) CT image sets were reconstructed by using FBP algorithm and that of using IR algorithm with a 60%/40% blend of IR-FBP reconstruction at 80-kV(p) image set (protocol C). Scans obtained during 3 hepatic phases were subjected to quantitative and qualitative analysis.

RESULTS:

The mean radiation dose and the contrast medium dose were significantly lower under protocols B and C than under protocol A. In all hepatic phases, all signal-to-noise and contrast-to-noise ratios were greater under protocol C than under other protocols at all anatomic sites. Qualitative analysis showed that image noise and diagnostic acceptability were significantly higher under protocol C.

CONCLUSION:

In all hepatic phases, a low-tube voltage, low-contrast material dose CT with IR algorithm yielded better contrast enhancement and image quality than a standard tube voltage, standard contrast material dose CT with FBP in thin adult patients.

• Authors: Tomohiro Namimoto, Seitaro Oda, Daisuke Utsunomiya, Toshiaki Shimonobo, Sosuke Morita, Takeshi Nakaura, Yasuyuki Yamashita
• Journal: Journal of computer assisted tomography (J Comput Assist Tomogr) 2012 Jul-Aug Vol. 36 Issue 4 Pg. 495-501 ISSN: 1532-3145 [Electronic] United States
• PMID: 22805682 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Contrast Media
• Iopamidol

Topics

• Aged
• Aged, 80 and over
• Algorithms
• Biopsy
• Contrast Media (administration & dosage)
• Female
• Humans
• Iopamidol (administration & dosage)
• Liver Cirrhosis (diagnostic imaging)
• Liver Function Tests
• Male
• Middle Aged
• Radiation Dosage
• Radiographic Image Interpretation, Computer-Assisted (methods)
• Radiography, Abdominal (instrumentation, methods)
• Statistics, Nonparametric
• Tomography, X-Ray Computed (instrumentation, methods)