Prospective comparison of helical CT with angiography in pulmonary embolism: global and selective vascular territory analysis. Interobserver agreement

Abstract

The objective of this prospective study was to evaluate the sensitivity, specificity, positive and negative predictive values, and interobserver agreement in the diagnosis of pulmonary embolism with helical CT, compared with pulmonary angiography, for both global results and for selective vascular territories. Helical CT and pulmonary angiography were performed on 66 consecutive patients with clinical suspicion of pulmonary embolism. The exams were blindly interpreted by a vascular radiologist and by two independent thoracic radiologists. Results were analyzed for the final diagnosis as well as separately for 20 different arterial territories in each patient. Pulmonary angiography revealed embolism in 25 patients (38%); 48% were main, 28% lobar, 16% segmental, and 8% subsegmental. The sensitivity, specificity, and positive and negative predictive values of helical CT for observer 1 were, respectively, 91, 81.5, 75, and 94%; in 7.5% of the patients the exam was considered indeterminate. For observer 2 the values were, respectively, 88, 86, 81.5, and 91%; in 9% of the patients the exam was considered indeterminate. Main arteries were considered as non-valuable in 0-0.8%, the lobar in 1.5%, the segmental in 7.5-8.5%, and the subsegmental in 55-60%. Interobserver agreement for the final diagnosis was 80% (kappa 0.65). For each vascular territory, this was 98% (kappa 0.91) for main arteries, 92% (kappa 0.78) for lobar arteries, 79% (kappa 0.56) for segmental arteries, and 59% (kappa 0.21) for subsegmental arteries. Helical CT is a reliable method for pulmonary embolism diagnosis, with good interobserver agreement for main, lobar, and segmental territories. Worse results are found for subsegmental arteries, with high incidence of non-valuable branches and poor interobserver agreement.

Radiation Dosimetry of the Fibrin-Binding Probe 64Cu-FBP8 and Its Feasibility for PET Imaging of Deep Vein Thrombosis and Pulmonary Embolism in Rats

“…While the clinical performance of 64 Cu-FBP8-PET remains to be demonstrated, the high thrombus uptake observed in this study for both PE and DVT suggests the potential of this molecular imaging approach using PET. The high target:background contrast may allow imaging of emboli in the distal branches of the pulmonary circulation, detected with lower sensitivity by CT angiography (3). Moreover, 64 Cu-FBP8-PET may provide an alternative to contrast-enhanced CT for detection of PE in renally-insufficient patients.…”

“…While contrast-enhanced computed tomography (CT) has become the gold standard for PE (1, 2), its sensitivity decreases as the location of the PE becomes more distal (3). Furthermore, contrast-enhanced CT is contraindicated in patients with poor renal function owing to the risk of contrast-induced nephrotoxicity.…”

Computed tomography pulmonary angiogram diagnosis of pulmonary embolism

“…Practical advantages of spiral CT include ready availability, minimally invasive, rapid, cost-effective availability for follow up and same frequency of technically inadequate examination as catheter angiography, which is approximately 5%. 23,24 Spiral CT pulmonary angiography (CTPA) is a routine 24-h/day technique. The CT scan is more readily accessible than a nuclear medicine study and obviates the complications that occur by heart catheterization in catheter angiography in high-risk patients.…”

Multidetector CT pulmonary angiography features of pulmonary embolus

“…The incidence of indeterminate studies is reported to be between 0.5 and 10.8% with a mean of 6.4%. 5,[24][25][26][27][28][29][30][31][32] The two most common causes are respiratory motion and poor contrast enhancement. 24…”