Perfusion pulmonary scintigraphy showing numerous lung zones without fixation (amputation) due to multiple pulmonary embolisms.
Picture courtesy of Docteur
Ph Granier website
Two types of pulmonary scintigraphis exist: perfusion scintigraphy and ventilation scintigraphy.
Perfusion scintigraphy needs the injection of radioactive biodegradable particles with diameter of around 10 microns. These particles are momentarily stopped in pulmonary capillaries. Bad or poorly perfused zones will not stop the radioactive particles. There is no risk for the patient because the particles are biodegradable.
The major indication is pulmonary embolism which shows a specific non radioactive zone: of course other pathologies (most often already known like pulmonary insufficiency) may show alterations of pulmonary perfusion. On the contrary, a normal pulmonary scintigraphy eliminates the diagnosis of pulmonary embolism.
If at the same time, a perfusion scintigraphy is combined with ventilation scintigraphy, the diagnostic power of the examination is increased, since in embolism the ventilation is conserved whereas perfusion is limited.
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Perfusion pulmonary scintigraphy showing numerous lung zones without fixation (amputation) due to multiple pulmonary embolisms. |
Picture courtesy of Docteur
Ph Granier website |
Ventilation scintigraphy allows a separate analysis of the ventilation of the pulmonary lobes. They are most useful to study the functional pulmonary capacity if combined with classical respiratory functional tests.
In preoperative situation, the diminution of the ventilation induced by a surgical resection can be calculated (before a lobectomy or a pneumonectomy). A heavy smoker may have such a strong obstructive or restrictive bronchopathy associated with a cancer. If, after surgery, the remaining pulmonary parenchyma is unable to assure sufficient gazeous exchanges, then the intervention might lead to a very debilitating situation for the patient.
| Pulmonary ventilation scintigraphy: we can study the three different phases of respiratory movements. [A] : inhalation, [B] stabilisation, [C] expiration. Normal aspect can be seen on the curve n° 1. A restrictive pathology is found on the curve n°2 with a prolonged expiration (greater than the usual time). An obstructive pathology is found on the curve n°3 : the quantity of air (radioactive Xenon) at inspiration and expiration is diminished. Every pulmonary zone can be separately studied: the pulmonary capacity of the patient after surgery can then be calculated. |
Picture courtesy of Docteur
Ph Granier website |
