title: Assessment of sub-milli-sievert abdominal computed tomography with iterative reconstruction techniques of different vendors.
abstract: OBJECTIVE
  To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (SD) CT.
  
  
  METHODS
  In an Institutional Review Board approved study, 66 patients (mean age 60 ± 13 years, 44 men, and 22 women) undergoing routine abdomen CT on multi-detector CT (MDCT) scanners from vendors A, B, and C (≥ 64 row CT scanners) (22 patients each) gave written informed consent for acquisition of an additional RD CT series. Sinogram data of RD CT was reconstructed with two vendor-specific and a vendor-neutral IRTs (A-1, A-2, A-3; B-1, B-2, B-3; and C-1, C-2, C-3) and SD CT series with filtered back projection. Subjective image evaluation was performed by two radiologists for each SD and RD CT series blinded and independently. All RD CT series (198) were assessed first followed by SD CT series (66). Objective image noise was measured for SD and RD CT series. Data were analyzed by Wilcoxon signed rank, kappa, and analysis of variance tests.
  
  
  RESULTS
  There were 13/50, 18/57 and 9/40 missed lesions (size 2-7 mm) on RD CT for vendor A, B, and C, respectively. Missed lesions includes liver cysts, kidney cysts and stone, gall stone, fatty liver, and pancreatitis. There were also 5, 4, and 4 pseudo lesions (size 2-3 mm) on RD CT for vendor A, B, and C, respectively. Lesions conspicuity was sufficient for clinical diagnostic performance for 6/24 (RD-A-1), 10/24 (RD-A-2), and 7/24 (RD-A-3) lesions for vendor A; 5/26 (RD-B-1), 6/26 (RD-B-2), and 7/26 (RD-B-3) lesions for vendor B; and 4/20 (RD-C-1) 6/20 (RD-C-2), and 10/20 (RD-C-3) lesions for vendor C (P = 0.9). Mean objective image noise in liver was significantly lower for RD A-1 compared to both RD A-2 and RD A-3 images (P < 0.001). Similarly, mean objective image noise lower for RD B-2 (compared to RD B-1, RD B-3) and RD C-3 (compared to RD C-1 and C-2) (P = 0.016).
  
  
  CONCLUSIONS
  Regardless of IRTs and MDCT vendors, abdominal CT acquired at mean CT dose index volume 1.3 mGy is not sufficient to retain clinical diagnostic performance.
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Atul
authors.initials: A
authors.lastname: Padole
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Nisha
authors.initials: N
authors.lastname: Sainani
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Diego
authors.initials: D
authors.lastname: Lira
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Ranish Deedar Ali
authors.initials: RD
authors.lastname: Khawaja
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Sarvenaz
authors.initials: S
authors.lastname: Pourjabbar
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Roberto
authors.initials: R
authors.lastname: Lo Gullo
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Alexi
authors.initials: A
authors.lastname: Otrakji
authors.affiliation: Atul Padole, Nisha Sainani, Diego Lira, Ranish Deedar Ali Khawaja, Sarvenaz Pourjabbar, Roberto Lo Gullo, Alexi Otrakji, Mannudeep K Kalra, Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, United States.
authors.forename: Mannudeep K
authors.initials: MK
authors.lastname: Kalra
keywords: Abdomen; Adult; Computed tomographic imaging; Radiation dose