In search of biologic correlates for liver texture on portal-phase CT.
OBJECTIVE
The acceptance of computer-assisted diagnosis (CAD) in clinical practice has been constrained by the scarcity of identifiable biologic correlates for CAD-based image parameters. This study aims to identify biologic correlates for computed tomography (CT) liver texture in a series of patients with colorectal cancer.


METHODS
In 28 patients with colorectal cancer, total hepatic perfusion (THP), hepatic arterial perfusion, and hepatic portal perfusion (HPP) were measured using perfusion CT. Hepatic glucose use was also determined from positron emission tomography (PET) and expressed as standardized uptake value (SUV). A hepatic phosphorylation fraction index (HPFI) was determined from both SUV and THP. These physiologic parameters were correlated with CAD parameters namely hepatic densitometry, selective-scale, and relative-scale texture features in apparently normal areas of portal-phase hepatic CT.


RESULTS
For patients without liver metastases, a relative-scale texture parameter correlated inversely with SUV (r = -0.587, P = .007) and, positively with THP (r = 0.512, P = .021) and HPP (r = 0.451, P = .046). However, this relative texture parameter correlated most significantly with HPFI (r = -0.590, P = .006). For patients with liver metastases, although not significant an opposite trend was observed between these physiologic parameters and relative texture features (THP: r < -0.4, HPFI: r > 0.35).


CONCLUSIONS
Total hepatic blood flow and glucose metabolism are two distinct but related biologic correlates for liver texture on portal phase CT, providing a rationale for the use of hepatic texture analysis as a indicator for patients with colorectal cancer.
Ganeshan
Balaji
B
Department of Engineering & Design, University of Sussex, Brighton BN1 9QT, England, UK. b.ganeshan@sussex.ac.uk
Miles
Kenneth A
KA
Young
Rupert C D
RC
Chatwin
Chris R
CR
D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008102:Liver Circulation; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000556:secondary*; D010477:Perfusion / Q000379:methods; D011877:Radionuclide Imaging; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods*