Improved delineation of the anterior spinal artery with model-based iterative reconstruction in CT angiography: a clinical pilot study.
OBJECTIVE
The purpose of this study was to investigate the utility of model-based iterative reconstruction (MBIR) for improving delineation of the anterior spinal artery (ASA) during routine-dose CT angiography.


METHODS
For imaging of 10 patients (six men, four women; mean age, 73.9 ± 7.5 years) consecutively undergoing CT angiography of the whole aorta with a 12-HU noise index, we used filtered back projection with a standard kernel, adaptive statistical iterative reconstruction of 40% with a detail kernel, and MBIR to reconstruct axial and oblique coronal multiplanar reformation images to delineate the ASA. We measured objective noise in the spinal cord and contrast-to-noise ratio (CNR) between the aorta and spinal cord on axial images at the T12 level. Two radiologists independently graded subjective noise and ASA delineation on the multiplanar reformation images from 1 (poor) to 4 (excellent). We compared results among the three reconstructions using one-way analysis of variance and Tukey-Kramer significance tests.


RESULTS
Objective noise, CNR, and subjective image noise and ASA delineation improved significantly with MBIR. Image noise was 18.4 ± 3.6 HU and CNR, 23.4 ± 8.6 (reader 1 scores, 3.9 ± 0.3 and 3.7 ± 0.5; reader 2, 3.9 ± 0.3 and 3.5 ± 0.7). With filtered back projection, image noise was 34.7 ± 8.3 HU and CNR 12.1 ± 4.0 (reader 1 scores, 2.0 ± 0.0 and 2.2 ± 0.4; reader 2, 2.2 ± 0.4 and 2.5 ± 0.7), and with ASIR, 33.0 ± 8.1 HU and 12.7 ± 4.3 (reader 1 scores, 2.0 ± 0.0 and 2.2 ± 0.4; reader 2, 2.2 ± 0.4 and 2.5 ± 0.7) (p < 0.05). Results between filtered back projection and adaptive statistical iterative reconstruction were comparable.


CONCLUSIONS
Use of MBIR can improve delineation of the ASA during CT angiography.
Department of Radiology, Tokyo Women's Medical University Medical Center East, 2-1-10 Nishiogu, Arakawa-ku, Tokyo 116-8567, Japan.
Haruhiko
H
Machida
Isao
I
Tanaka
Rika
R
Fukui
Kazuyo
K
Kita
Yun
Y
Shen
Eiko
E
Ueno
Shigeru
S
Suzuki
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000792:Angiography / Q000379:methods*; D001027:Aortography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011857:Radiographic Image Interpretation, Computer-Assisted; D013131:Spine / Q000098:blood supply*; D014057:Tomography, X-Ray Computed / Q000379:methods*