Question: A 65-year-old man with a history of pancreatic cancer undergoing chemotherapy. Emergency consultation for pain and edema of the entire lower limb from the groin. Which diagnostic test is more cost-effective to confirm the diagnostic suspicion? 
 Options:  <1> Dimer D. <2> Magnetic resonance. <3> Phlebography <4> Venous Doppler ultrasound. <5> Helical CT
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