The V/Q scan is requested for diagnosing or ruling pulmonary embolisms, in addition to diagnosing a number of lung diseases and follow up treatment. The test measures the air and blood flow into the lungs through two scans ventilation and perfusion which will be detailed bellow: Ventilation: This method is considered the first part of this examination, where the tracer will be inhaled through a nebulizer, specifically a mask will be placed and you will be requested to inhale the tracer for 10 minutes. Following, the imaging procedure will be conducted for 10-15 minutes. Perfusion: Instantly following the ventilation, you will be intravenously injected with the tracer, immediately after the injection the imaging procedure will be conducted, which will last for 10-15 minutes. Fasting: Not required. Medication contradiction: Medications may be resumed as usual.