Prevalence of noncardiac findings on low dose 64-slice computed tomography used for attenuation correction in myocardial perfusion imaging with SPECT

Electrocardiogram (ECG)-triggered, low dose computed tomography (CT) is increasingly used for attenuation correction in myocardial perfusion imaging (MPI) with SPECT. The purpose of the study was to assess the prevalence of relevant noncardiac findings in the field-of-view of such attenuation correction CT scans. Five hundred and eighty-two consecutive patients (211 female, 371 male; mean age: 64 ± 11 years; BMI: 27.7 ± 5.3 kg/m²) underwent 64-slice, ECG-triggered CT scanning for attenuation correction of MPI with SPECT. Relevant findings were defined as abnormalities that required clinical or radiological follow-up. Noncardiac findings were detected in 400 patients (68.7%). In 196 patients (33.7%) 226 relevant findings were detected. Findings included noncalcified pulmonary nodules (n = 156), interstitial lung disease (n = 6), pleural effusion (n = 20), pneumonia (n = 1), aortic aneurysm (n = 5), aortic dissection (n = 4), enlarged mediastinal lymph nodes (n = 5), mediastinal tumor (n = 3), breast abnormalities (n = 3), liver cirrhosis (n = 5), liver mass (n = 5), ascites (n = 5), splenomegaly (n = 2), renal mass (n = 1), hydronephrosis (n = 1), adrenal mass (n = 3), and bone metastasis (n = 1). As low dose 64-slice CT scans used for attenuation correction in MPI with SPECT reveal a high prevalence of noncardiac pathologic findings with potential clinical relevance, a systematic review of the CT scans appears mandatory.