Excessive thoracic computed tomographic scanning in sarcoidosis

Patterns of medication use and imaging following initial diagnosis of sarcoidosis

INTRODUCTION

Sarcoidosis is a rare inflammatory disease with unclear natural history. Using a large, retrospective, longitudinal, population-based cohort, we sought to define its natural history in order to guide future clinical studies.

METHODS

We identified 722 newly diagnosed cases of sarcoidosis within Kaiser Permanente Northwest health care records between 1995 and 2015. We investigated immunosuppressive medication use in the two years following diagnosis, analyzed demographic and clinical characteristics, and quantified chest imaging and pulmonary function testing (PFTs) across the clinical course.

RESULTS

Over two years of follow-up, 41% of patients were treated with prednisone. Of those, 75% tapered off their first course within 100 days, although half of those patients required recurrent therapy. Five percent of the entire cohort remained on prednisone for longer than one year, with an average daily dose of 10-20 mg. Chest imaging was associated with early prednisone use, and chest CT was associated with changes in prednisone dose. PFTs or demographics were not associated with prednisone use. Cumulative prednisone doses were significantly higher in African Americans (1,845 mg additional) and those who had a chest CT (2,015 mg additional). Overall, PFTs were less frequently obtained than chest imaging and had no significant change over disease course.

DISCUSSION

The natural history of sarcoidosis varies greatly. For those requiring therapy, corticosteroid burden is high. Chest imaging drives medication dose changes as compared to PFTs, but neither outcome fully captures the entire history of disease. Prospective cohorts are needed with purposefully collected, repeated measures that include objective clinical assessments and symptoms.

Uveitis for the non-ophthalmologist

The uveitides are a heterogeneous group of diseases characterized by inflammation inside the eye. The uveitides are classified as infectious or non-infectious. The non-infectious uveitides, which are presumed to be immune mediated, can be further divided into those that are associated with a known systemic disease and those that are eye limited,-ie, not associated with a systemic disease. The ophthalmologist identifies the specific uveitic entity by medical history, clinical examination, and ocular imaging, as well as supplemental laboratory testing, if indicated. Treatment of the infectious uveitides is tailored to the particular infectious organism and may include regional and/or systemic medication. First line treatment for non-infectious uveitides is corticosteroids that can be administered topically, as regional injections or surgical implants, or systemically. Systemic immunosuppressive therapy is used in patients with severe disease who cannot tolerate corticosteroids, require chronic corticosteroids at >7.5 mg/day prednisone, or in whom the disease is known to respond better to immunosuppression. Management of many of these diseases is optimized by coordination between the ophthalmologist and rheumatologist or internist.

Multidisciplinary approach and long-term follow-up in a series of 640 consecutive patients with sarcoidosis: Cohort study of a 40-year clinical experience at a tertiary referral center in Barcelona, Spain

Cohort studies of large series of patients with sarcoidosis over a long period of time are scarce. The aim of this study is to report a 40-year clinical experience of a large series of patients at Bellvitge University Hospital, a tertiary university hospital in Barcelona, Spain. Diagnosis of sarcoidosis required histological confirmation except in certain specific situations. All patients underwent a prospective study protocol. Clinical assessment and follow-up of patients were performed by a multidisciplinary team.From 1976 to 2015, 640 patients were diagnosed with sarcoidosis, 438 of them (68.4%) were female (sex ratio F/M 2:1). The mean age at diagnosis was 43.3 ± 13.8 years (range, 14-86 years), and 613 patients (95.8%) were Caucasian. At diagnosis, 584 patients (91.2%) showed intrathoracic involvement at chest radiograph, and most of the patients had normal pulmonary function. Erythema nodosum (39.8%) and specific cutaneous lesions (20.8%) were the most frequent extrapulmonary manifestations, but there was a wide range of organ involvement. A total of 492 patients (76.8%) had positive histology. Follow-up was carried out in 587 patients (91.7%), over a mean of 112.4 ± 98.3 months (range, 6.4-475 months). Corticosteroid treatment was administered in 255 patients (43.4%), and steroid-sparing agents in 49 patients (7.7%). Outcomes were as follows: 111 patients (18.9%) showed active disease at the time of closing this study, 250 (42.6%) presented spontaneous remission, 61 (10.4%) had remission under treatment, and 165 (28.1%) evolved to chronic sarcoidosis; among them, 115 (19.6%) with mild disease and 50 (8.5%) with moderate to severe organ damage. A multivariate analysis showed that at diagnosis, age more than 40 years, the presence of pulmonary involvement on chest radiograph, splenic involvement, and the need of treatment, was associated with chronic sarcoidosis, whereas Löfgren syndrome and mediastinal lymphadenopathy on chest radiograph were indicators of good outcome.Sarcoidosis is a multisystem disease with protean clinical-radiographic manifestations. Although almost half of patients follow a spontaneous resolution or under treatment, a significant number of them may have several degrees of organ damage. This study emphasizes the value of a multidisciplinary approach and long-term follow-up by specialized teams in sarcoidosis.

The Clinical Features of Sarcoidosis: A Comprehensive Review

Sarcoidosis has innumerable clinical manifestations, as the disease may affect every body organ. Furthermore, the severity of sarcoidosis involvement may range from an asymptomatic state to a life-threatening condition. This manuscript reviews a wide variety of common and less common clinical characteristics of sarcoidosis. These manifestations are presented organ by organ, although additional sections describe systemic and multiorgan presentations of sarcoidosis. The lung is the organ most commonly involved with sarcoidosis with at least 90 % of sarcoidosis patients demonstrating lung involvement in most series. The skin, eye, liver, and peripheral lymph node are the next most commonly clinically involved organs in most series, with the frequency of involvement ranging from 10 to 30 %. The actual frequency of sarcoidosis organ involvement is probably much higher as it is frequently asymptomatic and may avoid detection. This is particularly common with lung, liver, cardiac, and bone involvement. Cardiac sarcoidosis is present in 25 % of all sarcoidosis but only causes clinical problems in 5 % of them. Nevertheless, unlike sarcoidosis involvement of most other organs, it may be suddenly fatal. Therefore, it is important to screen for cardiac sarcoidosis in all sarcoidosis patients. All sarcoidosis patients should also be screened for eye involvement as asymptomatic patients may have eye involvement that may cause permanent vision impairment. Pulmonary fibrosis from sarcoidosis is usually slowly progressive but may be life-threatening because of the development of respiratory failure, pulmonary hypertension, or hemoptysis related to a mycetoma or bronchiectasis. Some manifestations of sarcoidosis are not organ-specific and probably are the result of a release of mediators from the sarcoid granuloma. Two such manifestations include small fiber neuropathy and fatigue syndromes, and they are observed in a large percentage of patients.

The Diagnosis of Sarcoidosis

Sarcoidosis is a diagnosis of exclusion; there exists neither a pathognomonic clinical feature nor a perfect diagnostic test. Missed diagnosis and overdiagnosis are common. A careful history and physical examination look for "footprints" of sarcoidosis or features suggesting alternative diagnoses. Some presentations are classic and do not require tissue confirmation. A tissue biopsy should be performed if doubt exists. Sampling intrathoracic disease by transbronchial or ultrasound-guided biopsy of mediastinal lymph nodes provide high diagnostic yield with low complication rates. Even with tissue confirmation, diagnosis is never secure and follow-up is required to be fully confident of the diagnosis.

Admixture fine-mapping in African Americans implicates XAF1 as a possible sarcoidosis risk gene

Sarcoidosis is a complex, multi-organ granulomatous disease with a likely genetic component. West African ancestry confers a higher risk for sarcoidosis than European ancestry. Admixture mapping provides the most direct method to locate genes that underlie such ethnic variation in disease risk. We sought to identify genetic risk variants within four previously-identified ancestry-associated regions—6p24.3–p12.1, 17p13.3–13.1, 2p13.3–q12.1, and 6q23.3–q25.2—in a sample of 2,727 African Americans. We used logistic regression fit by generalized estimating equations and the MIX score statistic to determine which variants within ancestry-associated regions were associated with risk and responsible for the admixture signal. Fine mapping was performed by imputation, based on a previous genome-wide association study; significant variants were validated by direct genotyping. Within the 6p24.3–p12.1 locus, the most significant ancestry-adjusted SNP was rs74318745 (p = 9.4*10⁻¹¹), an intronic SNP within the HLA-DRA gene that did not solely explain the admixture signal, indicating the presence of more than a single risk variant within this well-established sarcoidosis risk region. The locus on chromosome 17p13.3–13.1 revealed a novel sarcoidosis risk SNP, rs6502976 (p = 9.5*10⁻⁶), within intron 5 of the gene X-linked Inhibitor of Apoptosis Associated Factor 1 (XAF1) that accounted for the majority of the admixture linkage signal. Immunohistochemical expression studies demonstrated lack of expression of XAF1 and a corresponding high level of expression of its downstream target, X-linked Inhibitor of Apoptosis (XIAP) in sarcoidosis granulomas. In conclusion, ancestry and association fine mapping revealed a novel sarcoidosis susceptibility gene, XAF1, which has not been identified by previous genome-wide association studies. Based on the known biology of the XIAP/XAF1 apoptosis pathway and the differential expression patterns of XAF1 and XIAP in sarcoidosis granulomas, we suggest that this pathway may play a role in the maintenance of sarcoidosis granulomas.

Laboratory support in the diagnosis of uveitis

Intraocular inflammations are still a diagnostic challenge for ophthalmologists. It is often difficult to make a precise etiological diagnosis in certain situations. Recently, there have been several advances in the investigations of uveitis, which has helped the ophthalmologists a lot in the management of such clinical conditions. A tailored approach to laboratory diagnosis of uveitic cases should be directed by the history, patient's symptoms and signs, and clinical examination. This review summarizes various modalities of laboratory investigations and their role in the diagnosis of uveitis.

[Thoracic sarcoidosis]

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. It mainly affects the thoracic lymph nodes and the lungs. The staging of sarcoidosis, which classifies patients according to their probability of spontaneous remission, is based on the plain chest film findings. Plain chest films are not as sensitive as high resolution computed tomography (HRCT) at detecting involvement of the lymph nodes, lungs, or bronchi. The high resolution CT findings can be typical, practically pathognomic, or atypical. High resolution CT provides information about the activity of the disease and detects incipient signs of fibrosis and other complications. To reach the diagnosis, it is necessary to correlate the clinical and radiological findings (and often the histological findings). Cardiac involvement can cause sudden death. The diagnosis of cardiac involvement is difficult; it is based on various imaging tests, like magnetic resonance imaging, which is more specific, and positron emission tomography. Diagnostic confirmation by endomyocardial biopsy is obtained in few patients.

Diagnosis of ocular sarcoidosis

INTRODUCTION

Sarcoidosis is a chronic inflammatory disorder with an unknown etiology characterized by noncaseating granulomas. The disorder is a multisystemic disease and affects many organs, including most often the lung, lymph nodes, skin, heart, liver, muscles, and the eye.

MATERIAL AND METHODS

[corrected] Based on a review of the literature and on an algorithm generated in an international workshop on sarcoidosis, this article provides the reader with a schematic and simple approach to the diagnosis of ocular sarcoidosis.

CONCLUSIONS

In a considerable proportion of cases it is the ophthalmologist who first sees patients presenting with the ocular expression of sarcoidosis. In countries where the incidence of sarcoidosis is common, like Japan, a complete workup should be performed, whereas in countries where the incidence of the disease is less high, a noninvasive approach may be warranted at first.

Outcome measures of the 6 minute walk test: relationships with physiologic and computed tomography findings in patients with sarcoidosis

Background

We assessed the relationship between physiologic parameters, computed tomography patterns, 6 minute walk distance (6MWD) and the distance-saturation product [DSP; defined as the product of the 6MWD and the lowest oxygen saturation during the 6 minute walk test (6MWT)]. In addition, we investigated factors affecting 6MWD in patients with pulmonary sarcoidosis.

Methods

We performed a retrospective study of patient demographics, treatment, pulmonary function, 6MWT, echocardiography and computed tomography results.

Results

Fifty nine patients were included in this study. Their mean+standard deviation age was 47.5 years + 12.5 years, and 42 (71.2%) were female. Mean pulmonary function parameters for forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁) and total lung capacity (TLC) results, as percentages of predicted values, were 77.6 ± 22.2, 77.1 ± 22.8 and 78.7 ± 16.1, respectively. Comparison of the DSP with distance walked revealed a significant correlation with factors underlying reduced 6MWD, including gender, pulmonary function indices, partial pressure of oxygen (PaO₂), and Borg dyspnea score. Other factors were significantly associated with DSP but not distance; these included lung fibrosis (p = 0.02), pulmonary hypertension (p = 0.01) and systemic therapy (p = 0.04). Backward elimination stepwise multiple regression analysis revealed that gender, and FEV₁ were independent predictors of 6MWD, but FEV₁ was more strongly related when DSP applied [DSP, R² = 0.53, p = 0.02; distance, R² = 0.45, p < 0.0001].

Conclusion

Our findings reveal that, compared to 6MWD alone, the DSP is correlated with a greater number of factors associated with reduced 6MWT performance. Therefore, the DSP may be a useful indicator of functional status in patients with sarcoidosis. Additional large-scale studies are warranted to validate our findings.

Clinical characteristics and computed tomography findings in Arab patients diagnosed with pulmonary sarcoidosis

BACKGROUND AND OBJECTIVE

Sarcoidosis is prevalent worldwide with significant heterogeneity across different ethnic groups. We aimed To describe the clinical characteristics and computed tomography findings among Arab patients with pulmonary sarcoidosis.

METHODS

A retrospective study of patient demographics, symptoms, co-morbid illness, sarcoidosis stage, treatment, pulmonary function and CT results.

RESULTS

Of 104 patients, most (77%) were 40 years of age or older at diagnosis, and females in this category (40 years ) significantly outnumbered male patients (69/104 (66.3%) vs. 35/104 (33.7%), P=.003). The most common complaints were dyspnea (76%), cough (72.1%) and weight loss (32.7%). The majority of patients displayed impairment in lung function parameters at presentation. However, significant impairment in forced vital capacity, percentage predicted (FVC%) (

CONCLUSION

At presentation, clinical manifestations of sarcoidosis among this sample of Arab patients were similar to reports from other nations. Further studies are needed to explore the effects of race and ethnicity on disease severity in the Middle East.

International criteria for the diagnosis of ocular sarcoidosis: results of the first International Workshop On Ocular Sarcoidosis (IWOS)

AIM

To report criteria for the diagnosis of intraocular sarcoidosis, taking into account suggestive clinical signs and appropriate laboratory investigations and biopsy results.

DESIGN

Concensus workshop of an international committee on nomenclature.

METHODS

An international group of uveitis specialists from Asia, Africa, Europe, and America met in a concensus conference in Shinagawa, Tokyo on October 28-29, 2006. Based on questionnaires that had been sent out prior to the conference, the participants discussed potential intraocular clinical signs eligible for a diagnosis of ocular sarcoidosis. A refined definition of clinical signs, which received two-thirds majority of votes, was included in the list of signs consistent with ocular sarcoidosis. Laboratory investigations were similarly discussed and those tests reaching a two-thirds majority were retained for the diagnosis of ocular sarcoidosis. Finally diagnostic criteria were proposed based on ocular signs, laboratory investigations, and biopsy results.

RESULTS

The concensus conference identified seven signs in the diagnosis of intraocular sarcoidosis: (1) mutton-fat keratic precipitates (KPs)/small granulomatous KPs and/or iris nodules (Koeppe/Busacca), (2) trabecular meshwork (TM) nodules and/or tent-shaped peripheral anterior synechiae (PAS), (3) vitreous opacities displaying snowballs/strings of pearls, (4) multiple chorioretinal peripheral lesions (active and/or atrophic), (5) nodular and/or segmental peri-phlebitis (+/- candlewax drippings) and/or retinal macroaneurism in an inflamed eye, 6) optic disc nodule(s)/granuloma(s) and/or solitary choroidal nodule, and (7) bilaterality. The laboratory investigations or investigational procedures that were judged to provide value in the diagnosis of ocular sarcoidosis in patients having the above intraocular signs included (1) negative tuberculin skin test in a BCG-vaccinated patient or in a patient having had a positive tuberculin skin test previously, (2) elevated serum angiotensin converting enzyme (ACE) levels and/or elevated serum lysozyme, (3) chest x-ray revealing bilateral hilar lymphadenopathy (BHL), (4) abnormal liver enzyme tests, and (5) chest CT scan in patients with a negative chest x-ray result. Four levels of certainty for the diagnosis of ocular sarcoidosis (diagnostic criteria) were recommended in patients in whom other possible causes of uveitis had been excluded: (1) biopsy-supported diagnosis with a compatible uveitis was labeled as definite ocular sarcoidosis; (2) if biopsy was not done but chest x-ray was positive showing BHL associated with a compatible uveitis, the condition was labeled as presumed ocular sarcoidosis; (3) if biopsy was not done and the chest x-ray did not show BHL but there were 3 of the above intraocular signs and 2 positive laboratory tests, the condition was labeled as probable ocular sarcoidosis; and (4) if lung biopsy was done and the result was negative but at least 4 of the above signs and 2 positive laboratory investigations were present, the condition was labeled as possible ocular sarcoidosis.

CONCLUSION

Various clinical signs, laboratory investigations, and biopsy results provided four diagnostic categories of sarcoid uveitis. The categorization allows prospective multinational clinical trials to be conducted using a standardized nomenclature, which serves as a platform for comparison of visual outcomes with various therapeutic modalities.

"End-stage" pulmonary fibrosis in sarcoidosis

Pulmonary fibrosis is an unusual "end stage" in patients with sarcoidosis. Fibrosis occurs in a minority of patients, and presents with a unique physiologic combination of airways dysfunction (obstruction) superimposed on the more common restrictive dysfunction. Imagin techniques are essential to the diagnosis, assessment and treatment of pulmonary fibrosis. Standard chest radiographs and CT scans may reveal streaks, bullae, cephalad retraction of the hilar areas, deviation of the trachea and tented diaphragm. Positive gallium and PET scans indicate residual reversible granulomatous disease and are important guides to therapy decisions. Treatment, usually with corticosteroids, is effective in those patients with positive scans, but fibrosis does not improve with any treatment. With severe functional impariment and patient disability, pulmonary hypertension and right heart failure may supervene for which the patient will require treatment. Oxygen, careful diuresis, sildenafil and bosentan may be salutary. These patients are candidates for lung transplantation.

Pulmonary sarcoidosis

Sarcoidosis is an inflammatory granulomatous disease that is characterized by diverse organ system manifestations, a variable clinical course, and a predilection for affecting relatively young adults worldwide. Abnormalities on chest radiographs are detected in 85% to 95% of patients who have sarcoidosis. Approximately 20% to 50% of patients who have sarcoidosis present with respiratory symptoms, including dyspnea, cough, chest pain, and tightness of the chest. The clinical course and manifestations of pulmonary sarcoidosis are protean: spontaneous remission occurs in approximately two thirds of patients; up to 30% of patients have chronic course of the lung disease, resulting in progressive, (sometimes life-threatening) loss of lung function. Morbidity that correlates to sarcoidosis occurs in 1% to 4% of patients.

Endobronchial ultrasound for the diagnosis of pulmonary sarcoidosis

BACKGROUND

The diagnosis of pulmonary sarcoidosis can be established by a variety of techniques. Transbronchial lung biopsy is often the preferred approach, but it is frequently nondiagnostic and carries a risk of pneumothorax and bleeding. Mediastinoscopy is often suggested as the next diagnostic step but entails significant cost and associated morbidity. Endobronchial ultrasound (EBUS) with transbronchial needle aspiration (TBNA) is emerging as a safe, minimally invasive tool for the primary diagnosis of mediastinal and hilar lymphadenopathy. The purpose of this study was to assess the utility of EBUS-TBNA for pulmonary sarcoidosis.

METHODS

Fifty consecutive patients who had been referred for EBUS-TBNA for suspected pulmonary sarcoidosis were included in the study. On-site cytology was used to assess the adequacy of the samples. The presence of noncaseating granulomas without necrosis in the appropriate clinical setting was deemed to be adequate for the diagnosis of pulmonary sarcoidosis. Patients with a negative EBUS-TBNA underwent further histologic biopsy or clinical follow-up to determine the final diagnosis.

RESULTS

Eighty-two lymph nodes with a median size of 16 mm (range, 4 to 40 mm) were punctured. EBUS-TBNA demonstrated noncaseating granulomas without necrosis in 41 of 48 patients (85%) with a final diagnosis of sarcoidosis. EBUS-TBNA, therefore, has a sensitivity of 85% for the primary diagnosis of pulmonary sarcoidosis.

CONCLUSIONS

EBUS-TBNA is a safe, minimally invasive tool for the primary diagnosis of pulmonary sarcoidosis that has a high diagnostic yield. EBUS-TBNA should be considered an appropriate alternative diagnostic technique for patients with suspected pulmonary sarcoidosis.

Sarcoidosis

There have been several new insights into the cause and treatment of sarcoidosis. Studies of genetic variation have shown that specific genetic polymorphisms are associated with increased risk of disease or affect disease presentation. These polymorphisms include variation of MHC and cytokines such as tumour necrosis factor (TNF). Not all investigators have come to the same conclusion, suggesting an interaction of various factors, including the patient's ethnic origin. Treatment of sarcoidosis varies considerably. Patients with symptomatic disease for more than 2-5 years have been of particular interest. Corticosteroids remain the standard of care in such cases, but immunosuppressive drugs have proved steroid-sparing in many patients. New agents, including pentoxifylline, thalidomide, and infliximab have proved useful in selected cases. The effectiveness of these agents seems to lie in their ability to block TNF, especially in the treatment of chronic disease.

High-resolution CT of diffuse lung disease: value and limitations

The relative speed with which HRCT has become the imaging technique of choice for evaluating patients with suspected lung disease can be regarded as a testament to its effectiveness. It is as well, however, to remember some of the caveats that apply to the interpretation of the numerous studies that have championed the clinical application of HRCT. It seems unlikely that CT will be supplanted in the near future by other cross-sectional or volumetric imaging techniques for the evaluation of diffuse lung disease. The scope for further technical refinement of the hardware aspects of HRCT is probably limited but improvements in postprocessing of image data, with the potential to advance understanding of the pathophysiology of diffuse lung disease, can be anticipated.

Löfgren's syndrome revisited: a study of 186 patients

PURPOSE

To evaluate the clinical features, the results of noninvasive tests and biopsies, and the outcome of patients with Löfgren's syndrome.

SUBJECTS AND METHODS

Patients diagnosed as having Löfgren's syndrome at a university hospital in Barcelona, Spain, from 1974 to 1996, were prospectively followed. Löfgren's syndrome was defined as the association of erythema nodosum or periarticular ankle inflammation with unilateral or bilateral hilar or right paratracheal lymphadenopathy.

RESULTS

Löfgren's syndrome was diagnosed in 186 patients. The mean age was 37 +/- 11 years, and 157 (85%) were women. In 91 patients (49%), symptoms started during the spring (P < 0.0001). Erythema nodosum, periarticular ankle inflammation, or both were present at onset in 173 patients (93%). At the time of diagnosis, 161 patients (87%) had no respiratory symptoms; 151 (81%) had stage I abnormalities on chest radiograph, 29 (16%) stage II, and 6 (3%) stage 0. Five percent of patients had decreased forced vital capacity, and 15% had decreased carbon monoxide diffusing capacity. Extrathoracic involvement was infrequent. Serum angiotensin-converting enzyme levels were increased in 50% of patients. Gallium-67 scans showed hilar uptake in all the studied patients, but it yielded useful additional diagnostic information only in those with normal chest radiographs or with unilateral hilar lymphadenopathy. The diagnosis was proven with biopsy results in 63% of patients. None of the patients without histologic confirmation were subsequently found to have a diagnosis other than sarcoidosis. In the 133 patients who were followed for a mean of almost 5 years, 11 (8%) continued to have active disease, and 8 (6%) had several recurrences between 18 months and 20 years after a complete resolution. A normal serum angiotensin-converting enzyme level at diagnosis was associated with disease resolution without recurrence.

CONCLUSION

Löfgren's syndrome is usually a self-limiting form of sarcoidosis. Histologic confirmation is not necessary in typical cases. In a small number of patients, the disease may remain active or recur long after its onset, although usually with mild organ dysfunction.

Nuclear imaging. 67Gallium, 201thallium, 18F-labeled fluoro-2-deoxy-D-glucose positron emission tomography

67Gallium scan has been used for years in sarcoidosis as a marker of activity, a determiner of the extent and distribution of the disease, a diagnostic support, and an aid in therapeutic management. Because of its limited sensitivity and specificity for sarcoidosis, however, it is currently used mainly to assist in diagnosis in difficult cases, particularly in those with isolated extrathoracic sarcoidosis. The finding of the typical lambda or panda patterns supports the diagnosis and reinforces the indication to perform an appropriate biopsy or Kveim-Siltzbach test. In addition, the detection of clinically silent extrathoracic uptake may provide sites for biopsy. 67Gallium scans' routine use in the follow-up of pulmonary sarcoidosis under treatment has decreased because that is best accomplished by means of serial chest radiographs and PFT. 201Thallium scintigraphy studies the myocardial perfusion and is complementary to echocardiography and 24-hour electrocardiographic monitoring in the assessment of sarcoid cardiac involvement. It typically shows segmental areas of decreased uptake in the ventricular myocardium that disappear or decrease in size during stress or after intravenous administration of dipyridamole. That reverse distribution is not specific for cardiac sarcoidosis, however, because it may also occur in other cardiomyopathies. PET is based on the increase of glucose metabolism in inflamed tissues. It may have great potential to assess sarcoidosis activity, but it is still largely experimental and is not routinely employed.

Pulmonary sarcoidosis

Sarcoidosis involves the bronchi or lung in more than 90 percent of patients. Intrathoracic manifestations are protean, ranging from asymptomatic bilateral hilar lymphadenopathy to chronic, progressive, (ultimately fatal), respiratory insufficiency. The clinical course is highly variable, and optimal management and treatment are controversial. We review the salient radiographic, physiologic, and histopathologic features of pulmonary sarcoidosis and discuss rare intrathoracic complications (e.g., bronchostenosis, mycetomas, nodular sarcoidosis, necrotizing sarcoid angiitis and granulomatosis, pulmonary vascular and pleural involvement). We discuss the chest radiographic staging system and the role of ancillary diagnostic modalities including high resolution thin section computed tomographic scans (HRCT), bronchoalveolar lavage, radionuclide scan, and serum angiotensin enzyme converting enzyme. Indications for therapy and an overview of therapeutic options are outlined.

Thoracic imaging--then and now

The chest radiograph has proved a robust diagnostic aid over the last century. The accumulation of knowledge about chest disease by radiography has been gained slowly during the last 90 years. New impetus has been given by the development of computed tomography and the recent refinements of high resolution and spiral computed tomography. The pathophysiological insights provided by these new techniques have been obtained in a remarkably short period, with the promise of more to come.