Subtraction-multiphase-CT unbeneficial for early detection of colorectal liver metastases.
OBJECTIVE
To assess the value of multiphase-subtraction-CT for early detection of colorectal-liver-metastases (CRLM).


METHODS
In 50 patients suspected of CRLM a routine pre-operative 4-phase-CT-scan of the upper abdomen was obtained. All 12 possible image subtractions between two different phases were constructed applying 3D-image-registration to decrease distortion artefacts induced by differences in inspiration volume. Two experienced radiologists initially reviewed the conventional 4-phase-CT for malignant and/or benign appearing lesions and at least 1-month hereafter the same 4-phase-CT now including the subtracted images. The results were compared to histology reports or to a combination of surgical exploration and intraoperative ultrasound together with results from pre-operative PET and follow-up examinations.


RESULTS
Although an additional number of 31 malignant appearing lesions were detected on the subtraction images, none proved to represent a true CRLM. Interobserver agreement (kappa) decreased from 0.627 (good) to 0.418 (fair).


CONCLUSIONS
Adding linearly co-registered subtraction-CT images to a conventional 4-phase-CT protocol does not improve detection of CRLM.
Meijerink
Martijn R
MR
Department of Radiology, Vrije Universiteit Medisch Centrum, Amsterdam, The Netherlands. mr.meijerink@vumc.nl
van Waesberghe
Jan Hein T M
JH
Golding
Richard P
RP
van der Weide
Lineke
L
van den Tol
Petrousjka
P
Meijer
Sybren
S
van Kuijk
Cornelis
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction / Q000379:methods; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000556:secondary*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*