Multidetector computed tomography pulmonary angiography (CTPA) enables highly accurate visualization of subsegmental vessels, resulting increased diagnosis of pulmonary embolism (PE). However, this increase has not been accompanied by a decrease in mortality, which suggests that overdiagnosis and a lower severity of illness offset the benefits of anticoagulation. Although single and multiple subsegmental PE probably have different clinical repercussions, most studies do not differentiate between them. The clinical significance of single isolated subsegmental pulmonary embolism (SISSPE) is unknown, but most patients with SISSPE receive anticoagulation, increasing...

Between 2007 and 2017, three thoracic radiologists with 10 to 20 years' experience reported all emergency CTPA studies done to rule out PE in our hospital. For the present study, we selected consecutive cases reported as SISSPE. We retrieved the following information from patients' charts: demographics (age, sex), comorbidities, history of VTE (venous thromboembolism), possible alternative diagnoses, other diagnostic tests for VTE, anticoagulation, bleeding complications, and the recurrence of VTE in the following 3 months. To determine whether false positives were present, 4 thoracic radiologists...

Fig. 1and Fig. 2 outline our findings. Of the 3839 CTPA studies done to rule out PE, 1021 (26.4%) detected PE; of these 59 were SISSPEs (1.5% of all studies and 5.8% of PEs). Anticoagulation was administered in 41 (69.5%) cases; bleeding occurred in 6 (14.6%). In 2 cases, bleeding was severe: one spontaneous rectus sheath hematoma that required embolization and one massive lung hemorrhage resulting in death. No recurrent thrombosis was documented in any patient with SISSPE, regardless of whether they received anticoagulation. In...

SISSPEs accounted for 5.8% of all cases of PE diagnosed before we implemented the updated guidelines. Even among experienced thoracic radiologists, concordance in the interpretation of subsegmental defects is low [4]. Our 35.6% false-positive rate corroborates Ghanima et al.’s [4] conclusion that experienced radiologists tend to overdiagnose PE. Anticoagulation was administered in 41 (69.5%) patients diagnosed with SISSPE, even though 33 (56%) patients had findings suggesting alternative diagnoses that could justify the symptoms. Given the high percentage of patients diagnosed with SISSPE who receive anticoagulation...

A. González López; Sabadell/ES - nothing to disclose E. Castañer González; Sabadell/ES - nothing to disclose M. Andreu Magarolas; Sabadell/ES - nothing to disclose X. Gallardo; Sabadell/ES - nothing to disclose E. Casanovas Navarro; Sabadell/ES - nothing to disclose E. Vall Foraster; Sabadell/ES - nothing to disclose Correspondence to: A. González (email: [email protected])

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