Diagnostic role of technitium-99m bone scan in severe COVID-19-associated myositis

Abstract

Coronavirus disease 2019 (COVID-19), initially appreciated as a respiratory illness, is now known to affect many organs in the human body. Significant data has become available on muscle involvement, with creatinine kinase elevations present in a significant percentage of patients. For those with suspected COVID-19-associated myositis, the imaging modality of choice has been gadolinium-enhanced magnetic resonance imaging; however, the use of technitium-99 m bone scan has not been previously reported. Here, we report two cases of COVID-19 patients with severe elevation in creatinine kinase who underwent technitium-99 m bone scan. The resulting images showed diffuse symmetrical muscle involvement. Both patients developed acute renal injury due to rhabdomyolysis. To our knowledge, this is the first report of bone scan as a diagnostic imaging modality for COVID-19-associated myositis.

Keywords: Bone scan; COVID; Myositis; Rhabdomyolysis.

Fig. 1

Tc-99m bone scan in Case #1 showing widespread radiotracer uptake.

Fig. 2

Tc-99m bone scan in Case #2 showing widespread radiotracer uptake.

Fig. 3

Muscle tissue from Case #2 showing myonecrosis (H&E stain; original magnification 40x).

Fig. 4

Numerous eosinophilic myoglobin casts with associated acute tubular injury in Case #2 (A); H&E stain, original magnification 200x). Strong staining of the casts for myoglobin (B); immunohistochemistry, original magnification 200x).