Computed Tomographic Scanning in Sarcoidosis

Abstract

Sarcoidosis is a granulomatous disease of unknown etiology that involves the lungs or intrathoracic lymph nodes in more than 90% of patients. The clinical spectrum of sarcoidosis is protean, but pulmonary manifestations often dominate. Chest radiographs are abnormal in 90 to 95% of patients with sarcoidosis; the most characteristic feature is bilateral hilar lymphadenopathy (BHL), present in 50 to 80% of patients. Pulmonary parenchymal infiltrates are present in 25 to 50% of patients. In this article, we review the radiographic features of sarcoidosis (both typical and atypical), and the impact of chest radiographic stage on long-term prognosis. Computed tomographic (CT) scans are more sensitive than chest radiographs in delineating parenchymal, mediastinal, and hilar structures, and distinctive CT patterns may be virtually pathognomonic for sarcoidosis in some patients. Routine CT scan is not appropriate to diagnose or manage sarcoidosis, but CT may be invaluable in patients with atypical clinical or chest radiographic findings or specific complications of sarcoidosis (pulmonary or extrapulmonary), or to assess prognosis. High-resolution thin-section CT scans (HRCT) may be helpful in selected patients with stage II or III sarcoidosis to discriminate active inflammation from irreversible fibrosis. This article discusses the salient HRCT features of sarcoidosis, accuracy of CT in the differential diagnosis, and correlations of HRCT with disease extent and activity, pulmonary function, and lesion reversibility.

Admixture Fine-Mapping in African Americans Implicates XAF1 as a Possible Sarcoidosis Risk Gene

“…Scadding staging was assessed with chest roentgenograms. Although computed tomography is more sensitive for detecting fibrotic changes in the lungs of sarcoidosis patients [43], the number of missed Stage IV cases is likely small [44]. Given the large number of Scadding Stage IV cases in our analysis (n = 190), such misclassification would likely have nominal effects on our results.…”

Ocular Manifestations of Biopsy-Proven Pulmonary Sarcoidosis in Korea

“…Higher serum ACE could indicate higher monocytic cell line activity or granulomatous inflammation [ 21 ]. The predictive value of ACE for diagnosing sarcoidosis is 47%, lower than that of chest radiographic findings [ 22 , 23 ]. Although there was no statistical significance, the rate of increased ACE level and mean ACE level was slightly higher in the group with ocular involvement in this study.…”

HRCT findings of pulmonary sarcoidosis; relation to pulmonary function tests

“…Supporting our hypothesis, studies have shown that parenchymal biopsies obtained from MNs in sarcoidosis patients revealed non-caseating granulomas. It is also well known that the shape of granulomas is usually round and their dimensions may vary from micrometers to millimeters [2,8,13,14]. Also, due to systemic nature of the disease, every single organ or system might be involved to some extent in sarcoidosis, even though we could not visualize all these possible localizations of the disease by conventional imaging/screening methods, because they can be too small in some organs or systems to be visualized with these techniques [3,15].…”

“…As a result, the demonstration of MNs might be considered as a good example for this condition in sarcoidosis patients. In many studies it was shown that the distribution of MNs was perilymphatic in HRCTs of patients with pulmonary sarcoidosis [3,5,8,14-16]. That is : MNs are mostly located in sub pleural regions, in broncho vascular bundles and sometimes in interlobular septae [3,8,16] indicating that the disease is related to lymphatic system from another point of view.…”