DIAGNOSIS OF PULMONARY METASTASES WITH TURBO-SE MR-IMAGING

The sensitivity of MR imaging for detection of pulmonary metastases wa s evaluated in 23 patients. The MR imaging was performed with T2-weigh ted turbo-spin-echo (TSE) sequences at 1.5 T. The MR images were compa red with spiral volumetric CT which served as the radiological standar d. All MR images were interpreted by two radiologists without knowledg e of CT findings. The MR imaging technique initially enabled correct i dentification of altogether 286 of 340 metastases (84%) resulting in s ensitivities of 36% (size of nodules < 5 mm), 83% (size of nodules 5-1 0 mm), 92% (size of nodules 10-15 mm), and 100% (size of nodules > 15 mm). Retrospectively with knowledge of CT findings an additional 39 me tastases were visible; 15 remained undetected even retrospectly. The r esults of this paper suggest that MRI still does not have a role for s creening for pulmonary metastases. It proves, however, that the incide ntal diagnosis of a pulmonary lesion on T2-weighted TSE images is high ly reliable in presenting a pulmonary nodule also visible on CT. Howev er, thus far the malignant nature especially of small nodules detected by MRI (as by CT) remains uncertain even in patients with known malig nant neoplasm.