CONTRIBUTIONS OF SPECT/CT IMAGING TO THE LYMPHOSCINTIGRAPHIC INVESTIGATIONS OF THE LOWER LIMB LYMPHEDEMA

Abstract

Lymphoscintigraphy is a safe and reliabletechnique for investigating lymphedema.However, interpretation of delayed planarconventional imaging may be questionable dueto the superimposition of soft tissues.Therefore, the aim of this retrospective studywas to evaluate the contribution of singlephoton emission computed tomography/computed tomography (SPECT/CT) tolymphoscintigraphic investigation in a selectedpopulation with abnormal interstitial activity.Forty one patients with lower limblymphedema either primary (n=17) orsecondary (n=5), or associated with chronicvenous insufficiency (n=19) underwentlymphoscintigraphy according to a standardprotocol. SPECT/CT imaging that startedimmediately after planar imaging covered thepart of the lower limbs with the mostsignificant interstitial activity. The CT imageswere also analyzed separately to identify thetypical honeycomb pattern of lymphedema.SPECT/CT identified additional abnormalitiesin vessels and soft tissues in 19 patients(46%). The additional information, primarilyrelated to dermal collateralization of flow,dermal backflow, lymphangioma, andlymphorrhea, aided in understanding thephysiopathology of edema and may haveinfluenced management in 35 patients (85%).The honeycomb appearance of the soft tissueswas noted on CT in most patients (90%). Thisstudy suggests that SPECT/CT is a promisingaddition to planar imaging in lymphoscintigraphicinvestigations of lymphedema.