Study-level label schema. If a study had at least one image annotated as
PE Present on Image, the study had additional labels for location (one
or more), RV/LV ratio (only one), and type (only one, where Acute PE is
assumed if neither Chronic PE nor Acute and Chronic PE is annotated).
Dashed lines indicate implied study-level labels. Similarly, if the
study was labeled as Indeterminate, it was annotated with one or more
quality assurance (QA) labels. Note that True Filling Defect not PE and
Flow Artifact are informational labels only and not included in this
diagram. LV = left ventricle, PE = pulmonary embolism, RV
= right ventricle.