Radiological-nuclear medicine hybrid diagnostics with SPECT/CT for chronic foot and ankle diseases : Anew and important diagnostic tool

Abstract

In contrast to standard methods (sonography, X‑ray, CT(computed tomography), MRI(magnetic resonance imaging), numerous diseases of the foot or ankle can be diagnosed using SPECT/CT (single photon emission computed tomography/computed tomography) with regard to their clinical relevance with high accuracy (up to > 90%). The aim of this review is to provide an up-to-date overview of the importance of SPECT/CT in selected diseases of the foot and ankle. Aliterature search was carried out in the Pubmed database using the following terms: SPECT/CT, SPECT, skeletal scintigraphy, CT, computed tomography, foot and ankle disease, OSG, tarsal root, foot pain. The publications were selected with regard to questions and diagnoses that frequently occur in foot and ankle diagnostics. Furthermore, papers that describe amore precise diagnosis, achange in therapy management or areduction in symptoms due to the use of SPECT/CT were selected. Several studies have shown that afocally increased bone metabolism in osteoarthritis and osteochondral lesions correlates significantly with the development of pain. The presence of symptomatic ossicles such as the os naviculare accessorium typeII and os trigonum can be clearly demonstrated with the help of SPECT/CT and cannot be assigned as the source of the symptoms as accurately with any other imaging method. Bony reactions in the area of coalitions, arthrodesis, osteosynthesis, occult fractures, prostheses and diabetic foot cannot be detected with comparable accuracy using any other imaging method, so that therapy concepts in unclear cases, based only on standard imaging are changed inup to 2/3 of cases by SPECT/CT information. SPECT/CT is useful when there are clinical uncertainties despite standard imaging.