Case Author(s): Lester Johnson, M.D., Ph.D. and Jerold Wallis, M.D. , 1/14/00 . Rating: #D4, #Q4

Diagnosis: Takayasu arteritis

Brief history:

Pleuritic chest pain and dyspnea, rule out pulmonary embolism


Perfusion images

View main image(vq) in a separate image viewer

View second image(vq). Ventilation images

View third image(xr). A PA chest radiograph is shown

View fourth image(mr). A coronal oblique image from pulmonary magnetic resonance angiography is shown

Full history/Diagnosis is available below

Diagnosis: Takayasu arteritis

Full history:

This 42-year-old woman has a history of Takayasu arteritis. The perfusion scan abnormalities are unchanged in comparison to a previous V/Q scan obtained 8 years earlier (not shown). Pulmonary angiography performed in the past demonstrated findings consistent with progressive Takayasu arteritis (not shown).


Xe-133 gas by inhalation and Tc-99m macroaggregated albumin (MAA) by intravenous injection


The comparison chest radiograph demonstrates small bilateral pleural effusions, right greater than left. There is a small amount of atelectasis or infiltrate at the left lung base. The Xe-133 ventilation images show a uniform distribution of activity on single-breath and washin images. There is no abnormal Xe-133 retention during the washout phase. The perfusion images show decreased activity within the superior and posterobasal segments of the left lower lobe. There is also decreased perfusion within the lingula. The right lung demonstrates large segmental defects in all lobes, unchanged in comparison to the previous examination.

Magnetic resonance images of the chest demonstrate multiple areas of stenosis of the great vessels (brachiocephalic and left internal carotid), without significant change since seven months earlier. Multiple areas of stenosis and occlusion were also noted in both left and right pulmonary arterial systems (not shown), also unchanged.


Arteritis which involves medium to large vessels, such as polyarteritis nodosa and Takayasu arteritis, can cause mismatched subsegmental perfusion defects and hence are a known potential mimic of pulmonary embolism on ventilation/perfusion scintigraphy. The clinical history and comparison to prior studies are crucial for correctly interpreting these studies. Other potential mimics of acute pulmonary embolism include idiopathic pulmonary fibrosis (IPF) and radiation pneumonitis (which may pathologically be a type of vasculitis), generally seen in elderly patients, and multiple peripheral pulmonic stenoses, a congenital abnormality generally diagnosed in childhood. It should be noted that these moderate to large segmental perfusion defects are usually distinct from the small defects (sometimes referred to as "ratbites") that may be seen with small vessel vasculitis, such as Lupus, or pulmonary hypertension.

ACR Codes and Keywords:

References and General Discussion of Ventilation Perfusion Scintigraphy (Anatomic field:Vascular and Lymphatic Systems, Category:Other generalized systemic disorder)

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Case number: vq043

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