Detection of deep venous thrombosis by scanning of 99mtechnetium-labelled red-cell venous pool

A comparative study of 32 patients with suspected deep venous thrombosis was carried out using blood-pool radionuclide scanning and conventional x-ray phlebography. Results of the two methods showed close agreement, the sensitivity (positive correlation) of the scan being 100% and its specificity 89%. We conclude that a patient's red cells labelled with 99mtechnetium (99mTc) provide an excellent medium for this type of scanning. The technique has particular advantages in visualising the whole venous system, giving a persisting image, and obviating the need to inject into a vein of the affected limb. In view of the inherent disadvantages of contrast phlebography, 99mTc-red-cell scanning is clearly an acceptable alternative.