Luigi Camera MD, Presenter: Nothing to Disclose

FEDERICA ROMANO MD, Abstract Co-Author: Nothing to Disclose

IMMACOLATA LICCARDO MD, Abstract Co-Author: Nothing to Disclose

RAFFAELE LIUZZI, Abstract Co-Author: Nothing to Disclose

Pier Paolo Mainenti MD, Abstract Co-Author: Nothing to Disclose

Massimo Imbriaco MD, Abstract Co-Author: Nothing to Disclose

Laura Pizzuti, Abstract Co-Author: Nothing to Disclose

sabrina segreto MD, Abstract Co-Author: Nothing to Disclose

Marco Salvatore MD, Abstract Co-Author: Nothing to Disclose

To obtain a constant image quality in abdominal MDCT balancing radiation and contrast media dose administered to patients of different age.

52 (32 M; 22 F; aged 20-83 yrs) patients underwent a single-pass contrast-enhanced MDCT of abdomen and pelvis (coll. 1x32 mm; tube speed 36 mm/s; rotation time 0,75 s; helical pitch=27; rec. thickness = 5mm; 120 kVp; AEC) with scan delays of 70-90 seconds . Patients were divided into three different age-groups: A( 20-45 yrs); B (46-65 yrs); C (>65 yrs). For each group, a different Noise Index and contrast medium dose (Iopamiro 370 mgI/ml; Bracco Imaging) were selected as follows: A (NI=15; 2,5 cc/kg); B (NI =12,5; 2cc/kg); C (NI=7,5; 1,5cc/kg). Radiation exposure was reported as Dose Length Product (DLP; mGy/cm). Image quantitative analysis was performed by placing four circular regions of interest (ROIs) in different sections of liver parenchyma, aorta and sub-cutaneous fat tissue to calculate Signal to Noise (SNR) and Contrast to Noise ratios (CNR) for the liver (L) and aorta (A). Images were randomly evaluated by two radiologists that graded the image quality using standard criteria with a 5 point scale. analysis. Statistical analysis was performed by one-way ANOVA and by weighted Cohen kappa test to determine inter-observer agreement. 

No significant difference was observed in the SNR and CNR of both the liver (9,2±1,4, 9,2±1,1, 9,2±3 and 17±2, 19±3, 22±4) and aorta (12±2, 14±3, 17±5 and 21±2, 26±5, 32±6) for group A, B and C, respectively, whereas a statistically significant difference was observed between the radiation (mGy/cm) and the contrast media dose (ml) administered to group A (542±274 and 160±35), B (962 ±359 and 134±19;) and C (2134±583 and 110±19, p < 0.001), respectively. None of the studies was graded as poor or inadequate and inter-observer agreement for qualitative analysis was fair to moderate with weighted Cohen kappa values ranging from 0.37 to 0.63.  

A constant image quality in contrast-enhanced MDCT can be obtained balancing radiation and contrast media dose administered to patients of different ages.

Age-specific risks of radiation-induced cancer and contrast-induced nephropathy can be reduced preserving the image quality in contrast enhanced abdominal MDCT. 

Camera, L, ROMANO, F, LICCARDO, I, LIUZZI, R, Mainenti, P, Imbriaco, M, Pizzuti, L, segreto, s, Salvatore, M, Balancing Radiation and Contrast Media Dose in Multi-detector CT (MDCT): Prospective Evaluation of Image Quality.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019205.html