Investigations

• MRI ^b from inferior vena cava to popliteal veins. 
  Positive if central signal void with hyperintense signal or no flow in vessel (with or without intraluminal thrombus)

Why?

MRI can help diagnose and exclude DVT

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected DVT b (pre-test probability: %)	deep vein thrombosis (venography)	MRI	25 (8.1 to 75)	90%	0.0 (0.0 to 0.11)	0%