A Comparison of Single-Photon Emission CT Lung Scintigraphy and CT Pulmonary Angiography for the Diagnosis of Pulmonary Embolism

Background This study compared single-photon emission CT (SPECT) ventilation/perfusion (/) scintigraphy with multislice CT pulmonary angiography (CTPA). Methods In a prospective, observational study, 100 patients who were ≥ 50 years of age were recruited. Seventy-nine patients underwent both diagnostic 16-detector CTPA, and planar and SPECT / scintigraphy. The agreement between the CTPA and the SPECT / scintigraphy for the diagnosis of pulmonary embolism (PE) was calculated. The sensitivity and specificity of blinded SPECT scintigraphy reporting was calculated against a reference diagnosis made by a panel of respiratory physicians that was provided with CTPA and planar / scintigraphy reports, clinical information, and 3-month follow-up data. Results The observed percentage of agreement between SPECT / scintigraphy and CTPA data for the diagnosis of PE was 95%. When calculated against the respiratory physicians' reference diagnosis, SPECT / scintigraphy had a sensitivity of 83% and a specificity of 98%. Conclusions This study indicates that SPECT / scintigraphy is a viable alternative to CTPA for the diagnosis of PE and has potential advantages in that it was feasible in more patients and had fewer contraindications; lower radiation dose; and, arguably, fewer nondiagnostic findings than CTPA. Trial registration Australian New Zealand Clinical Trials Registry Registration Number: ACTRN12609000089235