[Diagnostic abilities of high-resolution CT, dynamic CT, and 201T1 SPECT in evaluating of pulmonary masses].

: The purpose of this study was to evaluate the diagnostic abilities of high-resolution CT (HRCT), dynamic CT (DCT), and T1-201 SPECT (T1) in determinating benignancy and malignancy (b-m) in pulmonary mass lesions. The diagnoses (35 adenocarcinomas, 10 squamous cell carcinomas, 6 other primary lung carcinomas, 8 tuberculomas, 13 other benignancies) were made in 20 patients (pts) by surgery, in 46 pts by biopsy or cytology, and in 6 pts by clinical course. In 72 pts (51 malignancies, 21 benignancies) who underwent DCT, increased attenuation of lesions at 90 seconds after the injection of contrast medium was a discriminative indicator, and the b-m threshold was defined as 22HU and 15HU for lesions of < or = 3cm and 3cm < in maximum diameter. In 56 pts (43 malignancies, 13 benignancies) examined by T1, lesion-to-contralateral normal lung ratios at 15 min (ER) and 3 hr (DR) were calculated, and the retention index (RI) was defined as (DR-ER)/ER 100. The b-m threshold of RI proved to be-6 for lesions of all sizes. In 40 pts (29 malignancies, 11 benignancies) who underwent both DCT and T1, HRCT was read on the basis of morphology by 7 observers (3 experienced, 2 senior, and 2 junior radiologists). Sensitivity and specificity were 88.2% and 71.4%, respectively, for DCT in 72 pts and 83.7% and 84.6% for T1 in 56 pts. A-receiver-operating characteristics (ROC) analysis revealed that only 2 experienced radiologists were superior to DCT and T1 in diagnostic accuracy. Sensitivity and negative predictive value were 100% and 100%, respectively, for the combination of DCT and T1, and 96.6% and 85.7% for the combination of the 2 experienced radiologists. In conclusion, the combination of DCT and T1 has excellent clinical efficacy in assessment b-m in pulmonary mass lesions.