Liver metastases on serial contrast-enhanced multidetector computed tomography examinations: Was the detection possible on previous examinations?

OBJECTIVE: To verify the earliest detectability of liver metastases in patients who underwent serial multidetector computed tomography (MDCT) examinations. METHODS: We selected 12 patients with known primary cancer who underwent 4 or more contrast-enhanced, 4-detector MDCTs. When metastases had been reported, an evaluation of the preceding MDCT was done to define whether the lesion was detectable, detectable only by minimal signs, undetectable, or detected but misdiagnosed as a benign lesion (MBL). RESULTS: Eighty-eight lesions were analyzed. Evaluating the preceding examination, we defined detectable (n = 8), detectable only by minimal signs (n = 5), undetectable (n = 74), and MBL (n = 1). The group with minimal signs was composed of 4 small hypodense foci and 1 calcification. The MBL was a non-Hodgkin lesion first misdiagnosed as a hemangioma. CONCLUSION: Approximately 15% of liver metastases were prospectively missed, 9% of them being retrospectively detectable, 6% being retrospectively visible as minimal signs, whereas only 1% of liver metastases were misdiagnosed as a benign lesion.