Abstract
Objectives. A retrospective study of bone scintigraphy to assess the prevalence of steatopygia on bone scintigraphy of obese patients and evaluate its effect on the appearance of the lumbar spine, and the added benefit of SPECT and SPECT/CT in overcoming possible artifacts.
Methods. Between 2016 and 2019, patients who underwent bone scintigraphy, BMI ≥ 30, were included. Three nuclear medicine consultants reviewed the studies to determine whether significant steatopygia is present, if it resulted in attenuation of underlying lumber spine and crease edge artifact. SPECT or SPECT/CT images were reviewed to evaluate their impact in diagnosis.
Results. 56 patients out of the 100 were noted with steatopygia on planar images. Among the group of 80 obese patients, 50% patients showed steatopygia, while in the group of 20 morbidly obese patients, 80% patients showed steatopygia. 32 patients of the 56 with steatopygia, had significant attenuation at the lower lumber vertebrae. Nine of these patients showed crease edge artifact. SPECT and SPECT/CT clarified the scintigraphic abnormalities noted in all patients including patients with edge artifact alleviating diagnostic difficulty. Among the nine patients with edge artifact, six patients showed normal appearance on SPECT/CT images while three showed true abnormalities.
Conclusions. Steatopygia is common on bone scintigraphy of obese patients, higher in females and morbidly obese patients. Obesity related artifacts in bone scintigraphy, including attenuation effect and edge artifact, are common in this patient group. SPECT or SPECT/CT improves the diagnostic accuracy by overcoming the steatopygia effects seen on planar images.