Figure 4: Imaging in sarcoidosis. (A ) Chest radiograph showing multiple poorly defined nodular shadows (arrows) in bilateral lung fields (B) HRCT scan axial section of the same patient showing large, discrete nodules (arrows) with fluffy margins in both lungs compatible with alveolar form of sarcoidosis. (C) Chest radiograph showing bilateral upper zone reticulonodular shadows; permanent pacemaker is also noted. Supraclavicular lymph node biopsy showed noncaseating epithelioid granulomas. The patient was referred with a possible diagnosis of MDR-TB. (D) Chest radiograph of the same patient after 6 months of corticosteroid therapy showing good response to treatment. (E) Axial T2W MR image of knee joint showing effusion in the joint space with synovial hypertrophy (arrow head). Synovial biopsy revealed non-caseating granulomas. (F) Axial CECT section showing pericardial effusion (arrow). There was good response to corticosteroids. (G) Axial CT scan of the chest showing pericardial calcification (arrow). (H) Axial CECT section showing significantly dilated main pulmonary artery (arrow). The diameter is more than adjacent aorta suggesting pulmonary hypertension. There is also marked peribronchovascular interstitial thickening. (I) Barium swallow image showing a localized filling defect (arrow) in mid-thoracic esophagus in a patient complaining of dysphagia for 3 months. CT revealed a subcarinal lymph nodal mass compressing the thoracic esophagus. (J) There was significant improvement in symptoms and radiographic appearance (arrow) after 3 months of corticosteroid treatment. (K) FDG PET-CT axial section showing increased focal uptake in liver (white arrow), spleen (arrow head) and kidney (black arrow). (L) FDG PET-CT axial section shows increased focal uptake in myocardium in a patient with cardiac sarcoidosis. (M) Coronal section FDG PET-CT scan showing increased FDG uptake in supraclavicular (arrow), mediastinal (arrow head), axillary and multiple mediastinal nodes in a patient with sarcoidosis. (N) Follow-up image after 6 months in the same patient shows good response with no abnormal uptake noted. (O) FDG PET-CT axial section showing increased uptake in parenchymal lesions (arrows) at initiation of therapy. (P) The parenchymal lesion showing no FDG uptake (arrows) in the same patient after 6 months of corticosteroid therapy.