Feasibility of integrated CT-liver perfusion in routine FDG-PET/CT.
OBJECTIVE
To integrate CT-perfusion into a routine, clinical contrast-enhanced (ce) PET/CT protocol for the evaluation of liver metastases and to compare functional CT and PET parameters.


METHODS
Forty-six consecutive patients (mean age: 60 (34-82) years; 20 f, 26 m) with known liver lesions (colorectal metastases (n = 34), primary liver cancer (n = 4), breast cancer (n = 3), anal cancer, gastric cancer, esophageal cancer, GIST, duodenal cancer (all: n = 1) who were referred for staging or therapy follow-up by [18F]-Fluoro-2-deoxy-D-glucose-positron-emission-tomography/computed-tomography imaging (FDG-PET/CT) were included. After acquisition of a low-dose PET/CT, a split-injection (70-90 mL) ce-CT-protocol, including a 35-s CT-perfusion scan of the liver and a diagnostic ce-CT of the thorax and/or abdomen (70 s delay, iv-contrast volume: 90 mL, 4 mL/s) was performed. CT-perfusion parameters (BF, BV, MTT,) and semi-quantitative PET-parameters (SUVmax, SUVmean, TLG, PETvol) were analyzed and compared.


RESULTS
CT-perfusion data could be obtained in all but one patient with shallow breathing. In all patients, diagnostic ce-PET/CT quality was adequate without the use of additional contrast media. Significant correlations (P < 0.05) were found for each of BF, BV, MTT, and SUVmax, further, BF and MTT correlated with TLG. Several other correlations were seen for other perfusion and PET-parameters.


CONCLUSIONS
Combined CT-perfusion/PET/CT-protocol without the use of additional contrast media is feasible and can be easily integrated in clinical routine. Perfusion parameters and PET-parameters are only partly correlating and therefore have to be investigated further at fixed time points during the course of disease and therapy.
Veit-Haibach
Patrick
P
Department of Medical Radiology, Division of Nuclear Medicine, University Hospital Zuerich, Raemistrasse 100, 8091, Zuerich, Switzerland. patrick.veit@gmx.de
Treyer
Valerie
V
Strobel
Klaus
K
Soyka
Jan D
JD
Husmann
Lars
L
Schaefer
Niklaus G
NG
Tschopp
Alois
A
Hany
Thomas F
TF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000473:pathology; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000473:pathology; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D055420:Perfusion Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted; D019275:Radiopharmaceuticals; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D007472:Iohexol; C038192:iopromide