Nontuberculous Mycobacterial Infection

Non-tuberculous mycobacteria (NTM), other than Mycobacterium tuberculosis (TB) may produce pulmonary infection. NTMI is typically an indolent infection except in immunocompromised and HIV infected patients. Imaging plays a crucial role in suggesting NTMI as a possible diagnosis in this patient population. Always consider classic or cavitary NTMI in patients with upper lobe cavitary disease similar to active cavitary TB. However, in such cases TB must always be excluded. In elderly white women, persistent right middle lobe/lingular atelectasis, bronchiectasis or consolidation should suggest the diagnosis of bronchiectactic NTMI. In patients with imaging findings of subacute hypersensitivity pneumonitis, the radiologist must review the history and consult with the clinician in order to identify the triggering allergen, including NTM which is associated with indoor hot tubs.