Preferred Label : top-of-the-knob sign;
Definition : Top of the aortic knob is not visible on a frontal radiograph; vertical interface
is often present in the left mediastinum. Suggests left lower lobe collapse.;
Source : Eisenberg, Ronald L. Atlas of Signs in Radiology.;
Origin ID : RID35644;
Associated condition(s)
Top of the aortic knob is not visible on a frontal radiograph; vertical interface
is often present in the left mediastinum. Suggests left lower lobe collapse.
