CT perfusion imaging of lung cancer: benefit of motion correction
for blood flow estimates
Lisa L. Chu
Robert J. Knebel
Aryan D. Shay
Ramsey D. Badawi
David R. Gandara
Friedrich D. Knollmann
Received: 17 November 2017 / Revised: 30 March 2018 / Accepted: 17 April 2018
European Society of Radiology 2018
Purpose CT perfusion (CTP) imaging assessment of treatment response in advanced lung cancer can be compromised by
respiratory motion. Our purpose was to determine whether an original motion correction method could improve the reproduc-
ibility of such measurements.
Materials and methods The institutional review board approved this prospective study. Twenty-one adult patients with non-
resectable non-small-cell lung cancer provided written informed consent to undergo CTP imaging. A motion correction method
that consisted of manually outlining the tumor margins and then applying a rigid manual landmark registration algorithm
followed by the non-rigid diffeomorphic demons algorithm was applied. The non-motion-corrected and motion-corrected images
were analyzed with dual blood supply perfusion analysis software. Two observers performed the analysis twice, and the intra- and
inter-observer variability of each method was assessed with Bland-Altman statistics.
Results The 95% limits of agreement of intra-observer reproducibility for observer 1 improved from −84.4%, 65.3% before
motion correction to −33.8%, 30.3% after motion correction (r = 0.86 and 0.97, before and after motion correction, p <0.0001for
both) and for observer 2 from −151%, 96% to −49 %, 36 % (r = 0.87 and 0.95, p < 0.0001 for both). The 95% limits of agreement
of inter-observer reproducibility improved from −168%, 154% to −17%, 25%.
Conclusion The use of a motion correction method significantly improves the reproducibility of CTP estimates of tumor blood
flow in lung cancer.
• Tumor blood flow estimates in advanced lung cancer show significant variability.
• Motion correction improves the reproducibility of CT blood flow estimates in advanced lung cancer.
• Reproducibility of blood flow measurements is critical to characterize lung tumor biology and the success of treatment in lung
Keywords Perfusion imaging
Tomography, x-ray computed
CTP CT perfusion
NSCLC Non-small cell lung cancer
RECIST Response Evaluation Criteria in Solid Tumors
SD Standard deviation
Patients with advanced lung cancer routinely receive chest CT
examinations to evaluate the efficacy of systemic therapy.
Response Evaluation Criteria in Solid Tumors (RECIST) has
been widely adopted to assess tumor response . Anti-
angiogenic treatments can impact tumor vascularity before
changes in tumor size become apparent. Therefore, it is pos-
sible that a survival benefit from anti-angiogenic drugs may be
demonstrated even in the absence of response by RECIST.
In non-small-cell lung cancer, changes in tumor size as a
surrogate marker for patient survival are unreliable [2, 3]. CT
measurements of tumor perfusion as an imaging biomarker of
* Friedrich D. Knollmann
Department of Radiology, University of California Davis Medical
Center, 4860 Y Street, Suite 3100, Sacramento, CA 95817, USA
Department of Internal Medicine, Division of Hematology and
Oncology, University of California Davis Medical Center,
Sacramento, CA, USA