Correspondence: The Radiological Investigation of Suspected Lower Limb Deep Vein Thrombosis

Imaging of venous thromboembolic disease

“…Recent ~ tudie high] ight the importance of hi tory and phy. ical examination a predictors of lower extremity DVT and when combined with clinical ri k fact r , can guide appropriate u e of imaging in those who need it most whit t excluding patient for whom it is not rel vant' :!• 11 • Common clinical situations such a calf tenderne and chronic unilateral welling Un the absence of risk factor ) clinically evident cellulitis and lower limb joint pain were not a sociated with acute DVT in a large eriesr 21 • The use of the D-dimer blood test promises to be a useful screening tool due to its very high negative predictive value for thrombus. It ha been predicted that inappropriate lower limb imaging referrals could be reduced by 35% if D-dimer levels are norma]H>.…”

“…Thus isolated calf thrombus is uncommon and it would prolong examination time to try to find it in a relatively small number of patients< 81 • Emboli from calf thrombus would cause small PE which are non-fatal and probably not clinically significant< 9 i _ The risk of PE following negative thigh USV examination is extremely low (0.3 %) in symptomatic patients< 8 ). It is known that undetected calf thrombus can propagate into proximal veins in a minority of ea es (7.7 %) o it has been proposed that selected patients remaining symptomatic after initial USV should have a repeat study at approximately 10 days< 10 l. A recent survey of 65 UK radiology departments revealed that only two routinely perform such follow-up scans< 11 >.…”