Ventilation – perfusion (V/Q) scintigraphy

Segmental defect• Occlusion of a branch of a branch of the pulmonary

artery• Wedge shape and pleural based• Conforms to segmental anatomy of the lung• Large (>75%), moderate (25~75%), small (<25%)

A branching lung network model (MRI-based)

Ventilation – perfusion scintigraphy

V / Q match• Both scintigrams are abnormal in the same

area, defects of equal size

V / Q mismatch• Abnormal perfusion in the area of normal

ventilation or much larger perfusion abnormality than ventilation defect

V/Q scan

Matching perfusion & ventillation defect

Scintigraphic image ofpulmonary embolism

Normal 99mTc-MAA perfusion& 81mKr ventillation

Perfusion Scintigraphy planar technique

Perfusion Scintigraphy planar technique

Perfusion Scintigraphy SPECT technique

Lung uptake ratio before plannedpulmonectomy

Ventilation Scintigraphy planar technique

Pulmonary artery agenesia

Dynamic inhalation lung scintigraphy (DIS)

Normal DTPA clearance

Faster DTPA clearance

Enhanced 99mTc DTPA clearance:• smoking (reversible)• alveolitis• sarcoidosis• pneumonitis• flame inhalation• interstitial pneumonia• lung manifestations of immunological diseases