TY - JOUR
T1 - Abdominal CT
T2 - Comparison of low-dose CT with adaptive statistical iterative reconstruction and routine-dose CT with filtered back projection in 53 patients
AU - Sagara, Yoshiko
AU - Hara, Amy K.
AU - Pavlicek, William
AU - Silva, Alvin C.
AU - Paden, Robert G.
AU - Wu, Qing
PY - 2010/9
Y1 - 2010/9
N2 - OBJECTIVE. The purpose of this article is to retrospectively compare radiation dose, noise, and image quality of abdominal low-dose CT reconstructed with adaptive statistical iterative reconstruction (ASIR) and routine-dose CT reconstructed with filtered back projection (FBP). MATERIALS AND METHODS. Fifty-three patients (37 men and 16 women; mean age, 60.8 years) underwent contrast-enhanced abdominal low-dose CT with 40% ASIR. All 53 patients had previously undergone contrast-enhanced routine-dose CT with FBP. With the scanning techniques masked, two radiologists independently graded images for sharpness, image noise, diagnostic acceptability, and artifacts. Quantitative measures of radiation dose and image noise were also obtained. All results were compared on the basis of body mass index (BMI). RESULTS. The volume CT dose index (CTDIvol), dose-length product, and radiation dose for low-dose CT with ASIR were 17 mGy, 860 mGy, and 13 mSv, respectively, compared with 25 mGy, 1,193 mGy, and 18 mSv for routine-dose CT with FBP, representing an approximate overall dose reduction of 33%. Low-dose CT with ASIR had significantly reduced (p < 0.001) quantitative and qualitative assessment of image noise. Image sharpness, however, was significantly reduced for low-dose CT with ASIR (p < 0.001), although diagnostic acceptability and artifact scores were nearly identical to those for routine-dose CT with FBP. The average CTDIvol dose reduction was 66% for patients with a BMI of less than 20 and 23% for patients with a BMI of 25 or greater. CONCLUSION. Compared with routine-dose CT with FBP, abdominal low-dose CT with ASIR significantly reduces noise, thereby permitting diagnostic abdominal examinations with lower (by 23-66%) radiation doses. Despite reduced image sharpness in average and small patients, low-dose CT with ASIR had diagnostic acceptability comparable to that of routine-dose CT with FBP.
AB - OBJECTIVE. The purpose of this article is to retrospectively compare radiation dose, noise, and image quality of abdominal low-dose CT reconstructed with adaptive statistical iterative reconstruction (ASIR) and routine-dose CT reconstructed with filtered back projection (FBP). MATERIALS AND METHODS. Fifty-three patients (37 men and 16 women; mean age, 60.8 years) underwent contrast-enhanced abdominal low-dose CT with 40% ASIR. All 53 patients had previously undergone contrast-enhanced routine-dose CT with FBP. With the scanning techniques masked, two radiologists independently graded images for sharpness, image noise, diagnostic acceptability, and artifacts. Quantitative measures of radiation dose and image noise were also obtained. All results were compared on the basis of body mass index (BMI). RESULTS. The volume CT dose index (CTDIvol), dose-length product, and radiation dose for low-dose CT with ASIR were 17 mGy, 860 mGy, and 13 mSv, respectively, compared with 25 mGy, 1,193 mGy, and 18 mSv for routine-dose CT with FBP, representing an approximate overall dose reduction of 33%. Low-dose CT with ASIR had significantly reduced (p < 0.001) quantitative and qualitative assessment of image noise. Image sharpness, however, was significantly reduced for low-dose CT with ASIR (p < 0.001), although diagnostic acceptability and artifact scores were nearly identical to those for routine-dose CT with FBP. The average CTDIvol dose reduction was 66% for patients with a BMI of less than 20 and 23% for patients with a BMI of 25 or greater. CONCLUSION. Compared with routine-dose CT with FBP, abdominal low-dose CT with ASIR significantly reduces noise, thereby permitting diagnostic abdominal examinations with lower (by 23-66%) radiation doses. Despite reduced image sharpness in average and small patients, low-dose CT with ASIR had diagnostic acceptability comparable to that of routine-dose CT with FBP.
KW - CT
KW - Iterative reconstruction
KW - Radiation dose
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U2 - 10.2214/AJR.09.2989
DO - 10.2214/AJR.09.2989
M3 - Article
C2 - 20729451
AN - SCOPUS:77956841482
SN - 0361-803X
VL - 195
SP - 713
EP - 719
JO - American Journal of Roentgenology
JF - American Journal of Roentgenology
IS - 3
ER -