Table 1.
Scores of the probability of liver metastasis on CT and MRI liver images (four-point scale).
Table 2.
Interobserver agreement concerning imaging analyses of rectal MRI involving additional liver imaging.
Table 3.
Diagnostic performance of T2WI, DWI, and CT for detecting liver metastasis.
Fig 1.
An 80-year-old male diagnosed with mid-rectal cancer with liver metastasis.
(A) A 1 cm nodule with intermediate signal intensity in segment five of the liver is noted on T2WI. (B) The nodule shows high signal intensity with diffusion restriction on DWI (b = 900 s/mm2). (C) The nodule is suspected but not confirmed to be delineated on CT. The patient underwent lower anterior resection for rectal cancer and segmentectomy for a liver lesion in segment five of the liver after concurrent chemo-radiation therapy. The liver lesion was confirmed as liver metastasis on histologic evaluation.
Table 4.
Comparison of the diagnostic performance in terms of detecting liver metastasis among T2-weighted imaging, diffusion-weighted imaging, and CT.
Table 5.
Univariate and multivariate logistic regression of imaging findings on MRI and tumor markers for predicting liver metastasis.
Fig 2.
A 56-year-old male diagnosed with distal rectal cancer.
(A) A 0.6 cm low attenuating nodule is noted in segment six of the liver on CT. It is difficult to determine whether it is a benign lesion or a small liver metastasis on CT. (B) The lesion shows high signal intensity on T2WI. (C) The nodule has high signal intensity on DWI (b = 50, 500 s/mm2) but iso-signal intensity on DWI (b = 900 s/mm2) without diffusion restriction. (D) The small nodule shows no interval change on follow-up CT obtained 2 years after initial CT.
Fig 3.
A 65-year-old female diagnosed with distal rectal cancer.
(A) Perivascular stranding around the small vessels with a signal void on T2WI was noted. (B) Vessels around the rectum show contrast filling after contrast injection. (C) A small nodule with high signal intensity on T2WI is noted in segment five. (D-E) The lesion shows high signal intensity on DWI (b = 900 s/mm2) (D) without diffusion restriction on the ADC map (E). (F) The nodule shows focal peripheral enhancement in segment five on CT. The lesion was considered to be a hemangioma. (G) At the 2-year follow up, the lesion appeared to be enlarged on T2WI liver MRI after the patient underwent a laparoscopic abdominal transanal proctosigmoidectomy with coloanal anastomosis. The lesion was confirmed as liver metastasis of mucinous adenocarcinoma after liver segmentectomy. (H) Another lesion with high signal intensity on segment one on T2WI was also resected and diagnosed as a biliary cyst.