Anti-phospholipid syndrome. suspected dvt so bilateral ultrasound/d dimer ordered. d dimer was negative. ultrasound was normal expect it stated (paroneal veins not demonstrated in both legs.) how common is dvt in this area ? safe to rule out dvt?

In general a negative D-dimer rules out DVT/PE, however in cases where the pretest probability is high it becomes hard to interpret. Best going forward would be to establish with a vascular surgeon that can escalate testing if clinical suspicion for acute DVT remains high. History as far as previous DVT’s is critical in this context.

Yes. A negative D-dimer is good test to rule out DVT. Lack of visualization of peroneal veins may be a developmental anomaly.