64-MDCT Pulmonary Angiography and CT Venography in the Diagnosis of Thromboembolic Disease

OBJECTIVE. The purpose of our study was to investigate whether CT venography (CTV) performed after CT pulmonary angiography (CTPA) using 64-MDCT provides additional findings in the diagnosis of thromboembolic disease. MATERIALS AND METHODS. Three hundred six consecutive patients in whom pulmonary embolism (PE) was clinically suspected were included in the study. The study group was classified according to the diagnostic quality of the CTPA examinations, the presence or absence of PE and deep venous thrombosis (DVT), and the most proximal localization that the embolus could lodge in the pulmonary artery. RESULTS. The diagnostic quality of CTPA was insufficient in 5.9%, acceptable in 8.2%, and excellent in 85.9% of the patients. The diagnostic quality of CTV was insufficient in 11.4%, acceptable in 47.4%, and excellent in 41.2%. The percentages of nondiagnostic examinations for CTPA and CTV were 5.2% and 10.8%, respectively. Acute PE and acute DVT were observed in 25.2% and 18.0%, respectively. The percentage of subsegmental emboli among patients with acute PE was 15.6%. The percentage of patients with thromboembolic disease was 29.1%. Of patients who were diagnosed as having thromboembolic disease, 13.5% (12 of 89 patients) had DVT only. Of all patients, 3.9% (12 of 306) had only isolated DVT. The number of patients with subsegmental PE who had DVT was two (0.7% all patients). CONCLUSION. As in MDCT scanning with a smaller number of slices, the combination of CTV with CTPA in 64-MDCT results in a small but definitive increase in the percentage of patients with a diagnosis of thromboembolic disease.