Balancing Radiation and Contrast Media Dose in Single-Pass Abdominal Multidetector CT: Prospective Evaluation of Image Quality.
OBJECTIVE
As both contrast and radiation dose affect the quality of CT images, a constant image quality in abdominal contrast-enhanced multidetector computed tomography (CE-MDCT) could be obtained balancing radiation and contrast media dose according to the age of the patients.


METHODS
Seventy-two (38 Men; 34 women; aged 20-83 years) patients underwent a single-pass abdominal CE-MDCT. Patients were divided into three different age groups: A (20-44 years); B (45-65 years); and C (>65 years). For each group, a different noise index (NI) and contrast media dose (370 mgI/mL) was selected as follows: A (NI, 15; 2.5 mL/kg), B (NI, 12.5; 2 mL/kg), and C (NI, 10; 1.5 mL/kg). Radiation exposure was reported as dose-length product (DLP) in mGy × cm. For quantitative analysis, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated for both the liver (L) and the abdominal aorta (A). Statistical analysis was performed with a one-way analysis of variance. Standard imaging criteria were used for qualitative analysis.


RESULTS
Although peak hepatic enhancement was 152 ± 16, 128 ± 12, and 101 ± 14 Hounsfield units (P < .001) for groups A, B, and C, respectively, no significant differences were observed in the corresponding SNRL with 9.2 ± 1.4, 9.1 ± 1.2, and 9.2 ± 3. Radiation (mGy × cm) and contrast media dose (mL) administered were 476 ± 147 and 155 ± 27 for group A, 926 ± 291 and 130 ± 16 for group B, and 1981 ± 451 and 106 ± 15 for group C, respectively (P < .001). None of the studies was graded as poor or inadequate by both readers, and the prevalence-adjusted bias-adjusted kappa ranged between 0.48 and 0.93 for all but one criteria.


CONCLUSIONS
A constant image quality in CE-MDCT can be obtained balancing radiation and contrast media dose administered to patients of different age.
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy; Institute of Biostructures and Bioimaging (C.N.R.), University "Federico II", Naples, Italy. Electronic address: camera@unina.it.
Luigi
L
Camera
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy.
Federica
F
Romano
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy.
Immacolata
I
Liccardo
Institute of Biostructures and Bioimaging (C.N.R.), University "Federico II", Naples, Italy.
Raffaele
R
Liuzzi
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy.
Massimo
M
Imbriaco
Institute of Biostructures and Bioimaging (C.N.R.), University "Federico II", Naples, Italy.
Pier Paolo
PP
Mainenti
Institute of Biostructures and Bioimaging (C.N.R.), University "Federico II", Naples, Italy.
Laura Micol
LM
Pizzuti
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy.
Sabrina
S
Segreto
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy.
Simone
S
Maurea
Section of Diagnostic Imaging, Department of Advanced Biomedical Sciences, University "Federico II", Via S. Pansini 5, Naples 80131, Italy.
Arturo
A
Brunetti
D000005:Abdomen / Q000000981:diagnostic imaging*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D011829:Radiation Dosage
D003287:Contrast Media
CT protocols; CT technique; contrast media; effective dose; image quality