From the Guidelines
Contrast is not needed for CT chest in pulmonary Mycobacterium avium complex (MAC) infection follow-up, as a non-contrast CT can adequately assess the extent and severity of bronchiectasis and other complications associated with the disease. According to the American College of Radiology Appropriateness Criteria, chest CT without IV contrast may be used to evaluate complications associated with bronchiectasis, including pneumonia and hemoptysis, and is often used in follow-up of conditions associated with bronchiectasis, such as chronic infections or interstitial lung diseases 1.
The use of non-contrast CT is supported by studies that have found that CT severity scores, which can be assessed without contrast, are associated with measures of airflow obstruction and prognosis in patients with non-tuberculous mycobacterial (NTMB) lung disease, including MAC infection 1. Additionally, non-contrast CT can be used to quantify the extent and severity of bronchiectasis, which is a common complication of MAC infection, using special software to calculate bronchial-arterial ratios, bronchial diameters, or bronchial surface area 1.
Some key points to consider when using non-contrast CT for MAC infection follow-up include:
- The ability to assess the extent and severity of bronchiectasis and other complications without the need for contrast enhancement
- The association between CT severity scores and measures of airflow obstruction and prognosis
- The use of special software to quantify the extent and severity of bronchiectasis
- The reduced risk of contrast-related adverse events, such as allergic reactions and nephrotoxicity, when using non-contrast CT 1.
Overall, the evidence suggests that non-contrast CT is a suitable imaging modality for follow-up of pulmonary MAC infection, and contrast is not routinely needed. However, contrast administration may be considered in specific situations, such as when there is concern for complications like hemoptysis or vascular involvement 1.
From the Research
CT Chest in Pulmonary Mycobacterium Avium Complex (MAC) Infection Follow-Up
- The use of contrast in CT chest for pulmonary MAC infection follow-up is not explicitly mentioned in the provided studies 2, 3, 4, 5, 6.
- However, the studies suggest that chest CT scans are a useful tool for assessing and predicting the efficacy of drug therapy for MAC pulmonary disease 4.
- Chest CT scans can help identify characteristic features of MAC infection, such as small nodules, cavities, bronchial wall thickening, infiltration, pleural thickening, and atelectasis 4, 5.
- The studies also highlight the importance of early diagnosis and treatment of MAC infection, and the role of chest CT scans in monitoring disease progression and response to treatment 2, 3, 5.
- A study comparing CT and MRI scans for assessing MAC pneumonia found moderate agreement between the two imaging modalities, but did not address the use of contrast in CT scans 6.
- Another study analyzed chest CT scans before and after antituberculous therapy in patients with MAC pulmonary disease, but did not mention the use of contrast 4.