TY - JOUR
T1 - Phase and amplitude binning for 4D-CT imaging
AU - Abdelnour, A. F.
AU - Nehmeh, S. A.
AU - Pan, T.
AU - Humm, J. L.
AU - Vernon, P.
AU - Schöder, H.
AU - Rosenzweig, K. E.
AU - Mageras, G. S.
AU - Yorke, E.
AU - Larson, S. M.
AU - Erdi, Y. E.
PY - 2007/6/21
Y1 - 2007/6/21
N2 - We compare the consistency and accuracy of two image binning approaches used in 4D-CT imaging. One approach, phase binning (PB), assigns each breathing cycle 2π rad, within which the images are grouped. In amplitude binning (AB), the images are assigned bins according to the breathing signal's full amplitude. To quantitate both approaches we used a NEMA NU2-2001 IEC phantom oscillating in the axial direction and at random frequencies and amplitudes, approximately simulating a patient's breathing. 4D-CT images were obtained using a four-slice GE Lightspeed CT scanner operating in cine mode. We define consistency error as a measure of ability to correctly bin over repeated cycles in the same field of view. Average consistency error μe ± σe in PB ranged from 18% ± 20% to 30% ± 35%, while in AB the error ranged from 11% ± 14% to 20% ± 24%. In PB nearly all bins contained sphere slices. AB was more accurate, revealing empty bins where no sphere slices existed. As a proof of principle, we present examples of two non-small cell lung carcinoma patients' 4D-CT lung images binned by both approaches. While AB can lead to gaps in the coronal images, depending on the patient's breathing pattern, PB exhibits no gaps but suffers visible artifacts due to misbinning, yielding images that cover a relatively large amplitude range. AB was more consistent, though often resulted in gaps when no data existed due to patients' breathing pattern. We conclude AB is more accurate than PB. This has important consequences to treatment planning and diagnosis.
AB - We compare the consistency and accuracy of two image binning approaches used in 4D-CT imaging. One approach, phase binning (PB), assigns each breathing cycle 2π rad, within which the images are grouped. In amplitude binning (AB), the images are assigned bins according to the breathing signal's full amplitude. To quantitate both approaches we used a NEMA NU2-2001 IEC phantom oscillating in the axial direction and at random frequencies and amplitudes, approximately simulating a patient's breathing. 4D-CT images were obtained using a four-slice GE Lightspeed CT scanner operating in cine mode. We define consistency error as a measure of ability to correctly bin over repeated cycles in the same field of view. Average consistency error μe ± σe in PB ranged from 18% ± 20% to 30% ± 35%, while in AB the error ranged from 11% ± 14% to 20% ± 24%. In PB nearly all bins contained sphere slices. AB was more accurate, revealing empty bins where no sphere slices existed. As a proof of principle, we present examples of two non-small cell lung carcinoma patients' 4D-CT lung images binned by both approaches. While AB can lead to gaps in the coronal images, depending on the patient's breathing pattern, PB exhibits no gaps but suffers visible artifacts due to misbinning, yielding images that cover a relatively large amplitude range. AB was more consistent, though often resulted in gaps when no data existed due to patients' breathing pattern. We conclude AB is more accurate than PB. This has important consequences to treatment planning and diagnosis.
UR - http://www.scopus.com/inward/record.url?scp=34249751028&partnerID=8YFLogxK
U2 - 10.1088/0031-9155/52/12/012
DO - 10.1088/0031-9155/52/12/012
M3 - Article
C2 - 17664557
AN - SCOPUS:34249751028
SN - 0031-9155
VL - 52
SP - 3515
EP - 3529
JO - Physics in Medicine and Biology
JF - Physics in Medicine and Biology
IS - 12
M1 - 012
ER -