Assessing How Normal Variations in CT Scanning Affects Its Interpretation

Stability of Radiomic Features for Abdominal Tumors on Contrast Enhanced CT

The purpose of the study is to see how measurements of tumor differences vary with slight changes in CT scan parameters. Reproducible radiomic features can be extracted for abdominal tumors, and specifically colorectal liver metastases, imaged with clinical CT scanners even in the setting of variable scan parameters and variable contrast timing. Participants will be consented to undergo an additional CT of their abdomen.

Inclusion Criteria:

• Patients ≥ 18 years of age on the day of signed informed consent
• Patients scheduled and approved for contrast enhanced CT that includes imaging of the abdomen and pelvis following the Department of Radiology standard of care protocol as per local institutional guidelines
• Patients with measurable colorectal liver metastases on prior imaging, with at least one tumor greater than 2.0 cm in axial maximal diameter

Exclusion Criteria:

• Patient who is pregnant and/or lactating
• Patient scheduled for CT that includes the abdomen with a multiphasic contrast enhanced protocol (e.g. Triple Phase or Quadruple Phase Liver CT)
• Patient who require reduced intravenous contrast dose based on the Department of Radiology contrast policy as per local institutional guidelines
• Any other medical condition, including mental illness or substance abuse, deemed by the Investigator to be likely to interfere with a patient's ability to sign informed consent, cooperate and participate in the study, or follow up procedures