Evaluation of the Diagnostic Value of SPECT/CT in Defining Foot and Ankle Pathologies

CATEGORY: Ankle Arthritis, Hindfoot, Midfoot/Forefoot INTRODUCTION/PURPOSE: The precise localisation of degenerative or inflammatory pathologies in foot and ankle can be difficult due to the complex anatomy of the joints. MRI plays a vital diagnostic role in these scenarios aiding the diagnosis and preoperative planning. Single-photon emission computed tomography combined with computed tomography (SPECT/CT) is a relatively new imaging technology that combines the sensitivity of nuclear medicine examinations with the anatomical detail of CT. The aim of this study is to analyse the diagnostic effectiveness of SPECT/CT in evaluating foot and ankle pathologies. METHODS: The authors retrospectively reviewed the medical records of all patients with a foot and/or ankle -related complaint that received SPECT/CT. Exclusion criteria included patients with inadequate follow-up and those that were not initially assessed by a senior foot and ankle surgeon. Collected data included demographic information, results from imaging, clinical progress and outcomes. RESULTS: 272 included in the study comprised of 156 females and 116 males with a mean age of 52,8 years (range 17-92 years). The acquisition of a SPECT/CT changed the initial diagnosis (from either clinical or radiographs or MRI) in 55% of the cases. SPECT/CT finding correlated with MRI only in 34% of the cases. From the remaining cases SPECT/CT partially correlated with MRI in 26% of cases no correlation was noted in 40%. In regards to patients that undergone a USS or CT guided injection following the finding of a SPECT/CT, 86% reported a transient or long-term improvement in the pain. Overall, the SPECT/CT added confidence to the clinical diagnosis in 89% of the cases while reduced the need of further investigations in 93%. CONCLUSION: SPECT/CT is a valuable tool in depicting foot and ankle pathologies. It was able to provide additional diagnostic value by demonstrating co-existing pathologies as a potential cause of pain. SPECT/CT and MRI exhibit different diagnostic specificity and the limitations of each scan should be taken into consideration. This study strongly supports the use of SPECT/CT as a complementary imaging method to MRI for enhancing diagnostic specificity and outcomes.