Table 1.
Main clinical and radiological features of sarcoidosis in different organs
| Location | Clinical features | Imaging findings |
|---|---|---|
| Liver | Hepatomegalia, enlargement of abdominal lymph nodes | Round or oval shaped hypoechoic nodules at ultrasonography; Hypodense nodules on CT images; Hypointense nodules on T2-weighted MRI sequences and on gadolinium-enhanced T1-weighted MRI acquisitions |
| Spleen | Patients can be asymptomatic or complain of fever, weight loss, and malaise | Ultrasound reveals splenomegaly with small hypoechoic nodules; Hypodense nodules after contrast-enhanced CT images; Nodular lesions with low signal in all sequences and visible in the early gadolinium-enhanced T1 images |
| Gastro-intestinal Tract | Disease involves gastric antrum, biliary tree, and parotid glands | Small ulcerations of gastrointestinal tract; Enlargement of parotid glands can be observed, with inhomogeneous or nodular pattern on enhanced CT images; Increased T2-signal intensity on MRI acquisitions of parotid glands |
| Lymphatic System | Lymphadenopathy or increased number of normal sized nodes | Enlarged nodes can be located in the periportal or para-aortocaval region, close to the liver hilus, adjacent to the celiac trunk or pancreas |
| Peritoneum | Ascites and multiple nodules | Hypoattenuating nodules on CT images, fluid accumulation in the abdomen |
| Kidneys | Nephrolithiasis, nephrocalcinosis, nephrogenic diabetes insipidus, renal insufficiency, acute interstitial nephritis | “Striated nephrogram” can be found on CT and MRI acquisitions; Granulomatous pseudotumor appears as hypo-/iso-/hyperatteanuating area on unenhanced CT scans, hypodense after contrast administration; Granulomatous pseudotumor shows low signal on early and delayed images after gadolinium administration |
| Central Nervous System | Signs of cranial nerve involvement; headache, seizure, meningeal irritation | Lesions are hyperintense on T2-weighted MRI images, located in the white and grey matter; Leptomeningeal localizations are more visible after contrast injection, showing increased signal on enhanced T1 acquisitions |
| Bone | Hands and feet are the most common locations | On conventional radiography, lesions produce a lacy pattern of osteolytic areas in the digits; Large bone and axial skeleton lesions can be detected as radiolucent or sclerotic areas |
| Heart | Conduction disturbances and arrhythmias, pericarditis | Granulomatous lesions are observed as areas of focal enhancement on cardiac MRI, most frequently located in myocardial wall or subepicardial region |
| Skeletal Sarcoidosis | Involves hand and feet; large bones and axial skeleton involvement is uncommon | Sclerotic areas consisting of hyperdense homogeneous areas, round or oval in shape; osteolysis produces a hypodense appearance Lesions with high signal intensity on T2-weighted images, high-density proton sequences and STIR acquisitions; on T1-weighted images, lesions are generally hypointense |