PMID- 26397333
OWN - NLM
STAT- MEDLINE
DCOM- 20151215
LR  - 20220311
IS  - 1546-3141 (Electronic)
IS  - 0361-803X (Linking)
VI  - 205
IP  - 4
DP  - 2015 Oct
TI  - High-Pitch Dual-Source MDCT for Imaging of the Thoracoabdominal Aorta: 
      Relationships Among Radiation Dose, Noise, Pitch, and Body Size in a Phantom 
      Experiment and Clinical Study.
PG  - 834-9
LID - 10.2214/AJR.15.14334 [doi]
AB  - OBJECTIVE: The purpose of this study was to investigate, both in a phantom 
      experiment and a within-patient clinical study the relationships among radiation 
      dose, image noise, pitch, and body size in MDCT angiography of the 
      thoracoabdominal aorta, with the use of high-pitch dual-source and standard-pitch 
      single-source acquisitions. MATERIALS AND METHODS: A proprietary tapered phantom 
      consisting of four ultrahigh-molecular-weight polyethylene cylinders was used to 
      mimic the body size ranges (small, medium, large, and extra large) of patients in 
      the United States. The phantom was imaged using both standard-pitch (0.8) and 
      various high-pitch (range, 2.0-3.2 [in increments of 0.4]) settings. 
      Standard-pitch and high-pitch acquisitions were also performed in 45 patients (27 
      men, 18 women; mean age, 67.6 years). RESULTS: At standard pitch, the volume CT 
      dose index (CTDIvol) increased with phantom size, in a logistic sigmoid 
      relationship. At high-pitch settings, the CTDIvol increased gradually in relation 
      to phantom size, up to a threshold (denoted by tCTDI[pitch]  approximately  48.3-7.5 pitch), 
      which linearly decreased (R(2) = 0.99) with pitch (maximum CTDIvol output at 
      pitch [maxCTDI(pitch)]  approximately  18.9-3.9 pitch). A linear decrease in the size-specific 
      dose estimate (SSDE) was observed beyond phantom size thresholds (tSSDE[pitch]  approximately  
      47.6-8.6 pitch) linearly decreasing (R(2) = 0.98) with pitch (maximum SSDE output 
      at pitch [maxSSDE(pitch)]  approximately  15.5-1.3 pitch). Image noise was statistically 
      significantly lower at standard pitch than at high-pitch settings (p = 0.01). In 
      patients, statistically significant differences were noted between standard and 
      high-pitch settings in the mean CTDIvol(10.8 +/- 2.6 and 8.3 +/- 0.7 mGy, 
      respectively), SSDE (11.3 +/- 2.1 and 8.8 +/- 1.5 mGy, respectively), and noise (9.7 
      +/- 2.2 and 14 +/- 4.2, respectively) (p < .0001, for all comparisons). CONCLUSION: 
      Lower radiation dose levels achieved with the use of a high-pitch technique 
      reflect limitations in tube output occurring for medium to large body sizes, with 
      an associated exponential increase in noise. The standard- and high-pitch 
      techniques yield similar radiation dose levels for small body sizes.
FAU - Mileto, Achille
AU  - Mileto A
AD  - 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, 
      Durham, NC 27710.
FAU - Ramirez-Giraldo, Juan Carlos
AU  - Ramirez-Giraldo JC
AD  - 2 Siemens Healthcare USA Inc., Malvern, PA.
FAU - Nelson, Rendon C
AU  - Nelson RC
AD  - 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, 
      Durham, NC 27710.
FAU - Hurwitz, Lynne M
AU  - Hurwitz LM
AD  - 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, 
      Durham, NC 27710.
FAU - Choudhury, Kingshuk Roy
AU  - Choudhury KR
AD  - 3 Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, 
      Durham, NC.
FAU - Seaman, Danielle M
AU  - Seaman DM
AD  - 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, 
      Durham, NC 27710.
FAU - Marin, Daniele
AU  - Marin D
AD  - 1 Department of Radiology, Duke University Medical Center, Box 3808 Erwin Rd, 
      Durham, NC 27710.
LA  - eng
PT  - Clinical Study
PT  - Journal Article
PL  - United States
TA  - AJR Am J Roentgenol
JT  - AJR. American journal of roentgenology
JID - 7708173
SB  - IM
MH  - Aged
MH  - Aorta/*radiation effects
MH  - Aortography/*methods
MH  - Body Size
MH  - Female
MH  - Humans
MH  - Male
MH  - Multidetector Computed Tomography/*methods
MH  - Phantoms, Imaging
MH  - *Radiation Dosage
MH  - Retrospective Studies
OTO - NOTNLM
OT  - MDCT
OT  - dual source
OT  - high pitch
OT  - noise
OT  - radiation dose
EDAT- 2015/09/24 06:00
MHDA- 2015/12/17 06:00
CRDT- 2015/09/24 06:00
PHST- 2015/09/24 06:00 [entrez]
PHST- 2015/09/24 06:00 [pubmed]
PHST- 2015/12/17 06:00 [medline]
AID - 10.2214/AJR.15.14334 [doi]
PST - ppublish
SO  - AJR Am J Roentgenol. 2015 Oct;205(4):834-9. doi: 10.2214/AJR.15.14334.