Abstract: Objective  To explore the value and clinical significance of direct multi-slice computed tomography venography(MSCTV) in diagnosing venous obstructive diseases. 
Methods  Forty-eight patients with high clinical suspicion of lower extremity venous thrombotic disease were examined by MSCTV. The original data were sent to the workstation for multiple image post-processing to find out the characteristic imaging manifestations of the disease, and compared with the digital subtraction angiography(DSA) results. 
Results  Among the 48 patients, 36 had deep vein thrombosis of lower extremities, 3 had simultaneous involvement of both lower extremities, 21 had left lower extremity involvement, and 12 had right lower extremity involvement. 27 had iliac vein compression syndrome and 18 had accompanied with deep vein thrombosis.With DSA results as the gold standard, the sensitivity and specificity of MSCTV for the diagnosis of deep venous thrombosis of lower extremities were 97.2% and 100.0%. 
Conclusion  MSCTV may be used as the first choice in diagnosing venous thrombosis of the lower extremity.

Key words: venous thrombosis, lower extremity, phlebography