From the Research
Effect of Sarcoidosis on V/Q Scan
- Sarcoidosis can manifest with clinical signs suggestive of pulmonary embolism (PE), making diagnosis challenging 1.
- V/Q scans may show perfusion defects in patients with pulmonary sarcoidosis, which can be misinterpreted as PE 2, 3.
- The presence of sarcoidosis can lead to mismatched ventilation and perfusion defects, making it difficult to rule out PE using V/Q scans alone 2.
Interpretation of V/Q Scan Results
- The criteria used for interpreting V/Q SPECT results can vary, but a diagnostic cutoff of at least 1 segmental or 2 subsegmental mismatches is recommended for confirming or excluding acute PE 4.
- V/Q SPECT can identify other cardiopulmonary diseases, including sarcoidosis, in patients with suspected PE, which can impact treatment and clinical outcome 3.
- The clinical context and additional diagnostic tests, such as CT pulmonary angiogram, may be necessary to distinguish between sarcoidosis and PE 1.
Clinical Implications
- Sarcoidosis can be an ancillary finding on V/P SPECT, and its presence can affect the interpretation of V/Q scan results 3.
- A high index of suspicion for sarcoidosis is necessary when interpreting V/Q scan results, especially in patients with clinical signs suggestive of PE 1.
- Further studies are needed to fully understand the impact of sarcoidosis on V/Q scan results and to develop guidelines for interpreting these results in patients with suspected PE 5, 2, 3.