Radionuclide Lung Imaging

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What is the main purpose of lung scintigraphy?

Assessing pulmonary perfusion and ventilation

Evaluating lung cancer surgery

Assessing pulmonary anatomy

Diagnosing pulmonary embolism noninvasively (correct)

Which imaging modality is considered the standard for evaluating pulmonary embolism?

X-ray

MRI

Lung scintigraphy

Computed tomography pulmonary angiography (correct)

What is the function of the pores of Kohn and the canals of Lambert in the lungs?

Expelling carbon dioxide

Preventing collapse of obstructed lung segments (correct)

Supplying oxygen to alveoli

Aiding in lung ventilation

In which part of the trachea do the mainstem bronchi divide into lobar bronchi?

Intrathoracic region Signup and view all the answers

Why are lobes and segments crucial for interpreting pulmonary images?

To localize lung pathology Signup and view all the answers

What is the role of bronchial arteries in the lungs?

Connect to the pulmonary circulation Signup and view all the answers

What is the main difference in ventilation between the upper and lower lungs in the upright position?

Ventilation is greater in the lower lungs. Signup and view all the answers

Where is perfusion maximal in the lungs when in the upright position?

In the lower third of the lungs Signup and view all the answers

Which position results in more even ventilation and perfusion throughout the lungs?

Supine position Signup and view all the answers

What happens to the V/Q ratio from the base to the apex of the lung?

It decreases Signup and view all the answers

What percentage of capillaries are blocked by technetium-99m macroaggregated albumin (MAA)?

Less than 0.1% Signup and view all the answers

What is recommended for injection to ensure good statistical distribution of MAA in adults for perfusion imaging?

Between 200,000 and 700,000 particles Signup and view all the answers

What is the biologic half-life of MAA in the lung?

2 to 4 hours Signup and view all the answers

Why is it important to inject technetium-99m MAA during quiet respiration with the patient supine?

To decrease perfusion gradient Signup and view all the answers

What is crucial for diagnosing pulmonary emboli?

Understanding clinical presentation and risk factors Signup and view all the answers

Which imaging technique demonstrates higher sensitivity in distinguishing chronic thromboembolic pulmonary hypertension from other types?

V/Q scanning Signup and view all the answers

What do matched V/Q abnormalities suggest in the context of lung diseases?

Airway disease Signup and view all the answers

Which lung condition may show distinct V/Q scan patterns with lower lung involvement?

Cystic fibrosis Signup and view all the answers

What do ventilation-perfusion (V/Q) scans help differentiate from pulmonary emboli based on bronchodilator response and clinical history?

Asthma Signup and view all the answers

What can cause nonsegmental perfusion defects in lung scanning?

Inflammatory diseases Signup and view all the answers

Which imaging technique is preferred for staging and response evaluation in lung cancer?

CT and PET/CT scans Signup and view all the answers

What do V/Q scans assist in differentiating from other conditions like pulmonary emboli in lung imaging?

Pneumonitis Signup and view all the answers

What can cause diffuse or scattered nonsegmental perfusion defects in lung scanning?

Pleural effusions Signup and view all the answers

What is a leading cause of death during pregnancy in the developed world?

Pulmonary embolism Signup and view all the answers

What is the most important use of a V/Q lung scan?

Monitoring pulmonary emboli Signup and view all the answers

In a ventilation scan, why can xenon be seen longer at the lung bases?

Larger lung volume Signup and view all the answers

What is a characteristic of normal DTPA aerosol ventilation images?

Homogeneous deposition from base to apex Signup and view all the answers

Why is accurate diagnosis crucial before starting anticoagulation and thrombolytic therapies?

To minimize the risk of morbidity Signup and view all the answers

Which imaging technique categorizes the probability of pulmonary emboli based on specific interpretive criteria like PIOPED?

V/Q scans Signup and view all the answers

Why are V/Q scans particularly recommended for follow-up in diagnosed cases?

To evaluate regional pulmonary function Signup and view all the answers

What is a challenge associated with CTPA as a diagnostic tool for pulmonary emboli?

Overdiagnosis leading to unnecessary treatment Signup and view all the answers

Why do small pulmonary emboli present a diagnostic challenge?

Less than 25% of patients exhibit classic symptoms Signup and view all the answers

Why is poor-quality portable supine film a concern when interpreting lung scans?

It may cause misinterpretations Signup and view all the answers

What is a distinguishing feature between aerosol scans and perfusion scans?

Visualized trachea and bronchi in aerosol scans Signup and view all the answers

What is the mean diameter of the aerosols administered to the patient?

0.5 μm Signup and view all the answers

In which type of patients is central deposition of larger particles common?

Patients with COPD Signup and view all the answers

Why is Xenon-133 used for evaluating ventilation and perfusion?

To assess regional ventilation Signup and view all the answers

What is required from the patient during a ventilation study using Xenon-133?

Cooperation for breathing on a closed spirometer system Signup and view all the answers

Which technique can be used along with SPECT for improved lung scan accuracy?

CT angiography Signup and view all the answers

What is the main limitation mentioned in using 99mTc-DTPA aerosols?

Small amount of activity delivered to the patient Signup and view all the answers

Why is it recommended to adjust the doses of 99mTc-MAA and 99mTc-DTPA aerosol when performing sequential imaging of ventilation and perfusion?

To prevent interference between the two agents Signup and view all the answers