|ECR 2018 / C-2572|
|An overview of immune-mediated diseases in the chest: imaging findings, serological markers and clinical correlations|
Findings and procedure details
Systemic Lupus Erythematosus
SLE affects people of all ages, genders, and ethnic groups, occurring more frequently in young women. Diagnosis is based on clinical features and serological autoantibodies. The presence of any four criteria listed on Table 2 , with at least one in the clinical and one in the immunologic category, qualifies the patient to have SLE.
- Pleural disease: the most common thoracic manifestation, seen as unilateral or bilateral pleural effusion in 30–50% of patients, often associated with pericardial effusion.
- Interstitial lung disease: rare complication, less frequent than in RA or SSc, showing patterns of UIP, and more commonly NSIP.
- Pulmonary embolism: related to deep venous thrombosis.
- Diffuse alveolar hemorrhage: rare and severe manifestation.
- Acute lupus pneumonitis: diagnosis of exclusion, usually seen as bilateral areas of consolidation.
- Shrinking lung syndrome: uncommon manifestation, presenting as a progressive loss of lung volume with dyspnea and pleuritic chest pain, shown as unilateral or bilateral diaphragmatic elevation without evidence of parenchymal lung disease.
- Mediastinal lymph node enlargement.
- Organizing pneumonia.
The incidence of RA is approximately 0.5–1% of the adult population, occurring more commonly in females between 25 and 55 years-old. Patients typically present with symptoms that result from joint, tendon or bursal inflammation. Diagnosis is based on signs and symptoms of chronic inflammatory arthritis, with additional information on laboratory and radiographic examinations. The revised classification criteria uses a score of 0–10. A score of ≥ 6 fulfills the requirements for definite RA ( Table 3 ).
- Pleural disease: most common thoracic manifestation, seen as pleural thickening, or less frequently as pleural effusion, which is usually small and unilateral, often self-limited.
- Interstitial lung disease: includes patterns of NSIP, UIP, COP and follicular bronchiolitis. There is higher incidence of UIP with its classical tomographic features. Ground-glass opacities may appear, generally less extensive than in NSIP. Fibrosis with areas of cavitation, limited to the upper lobes, can rarely occur and mimic tuberculosis.
- Obliterative bronchiolitis: mosaic attenuation and perfusion.
- Follicular bronchiolitis: common benign condition associated with multiple small centrilobular nodules and areas of ground-glass attenuation.
- Rheumatoid pulmonary nodules: identical to subcutaneous nodules, more frequent in men than women, usually seen in smokers and high rheumatoid factor titers, mostly asymptomatic. Well circumscribed nodules, measuring 0.5–5.0 cm, in the periphery of upper and middle lung regions, with possible cavitation and rarely calcifications.
- Cricoarytenoid arthritis: frequent manifestation with diverse and nonspecific symptoms (stridor, dyspnea, dysphagia, pain).
- Thoracic bone changes: resorption of the distal part of the clavicles and erosive arthritis of the shoulders.
SSc can present at any age, but is more frequent in females between 30-50 years. Incidence is higher in afro-descendants, who are more likely to have diffuse cutaneous disease associated with interstitial lung involvement and worse prognosis. Clinical features are variable, most commonly manifesting with skin thickening and variable involvement of internal organs.
The new classification criteria include clinical features, autoantibodies, and capillaroscopy results. A total score of ≥ 9 characterizes definite systemic sclerosis ( Table 4 ).
- Interstitial lung disease: most common finding, manifesting mainly with NSIP pattern, but also often UIP. Patients with NSIP have a better prognosis. CT appearance is variable, usually seen as ground-glass attenuation, consolidation, reticular pattern, and honeycombing, involving mainly the lower lobes, with a peripheral and posterior distribution.
- Ground-glass opacities: seen in almost all patients. The presence of traction bronchiectasis is an important clue.
- Pulmonary arterial hypertension: the main cause of death, having a better prognosis and benefiting of early treatment.
- Esophageal involvement: seen in 97% of cases, increases the incidence of complications such as aspiration pneumonia and bronchiolitis.
- Mediastinal lymph node enlargement: common.
- Pleural disease.
Prevalence of primary SS is about 0.5–1%, and 30% of patients with autoimmune rheumatic diseases suffer from secondary SS. The syndrome occurs mostly in middle-aged women, although may appear at any age. The clinical manifestations have a slow and benign course, and are related to diminished lacrimal and salivary gland function. New classification criteria(Table 5).
- Interstitial lung disease: most common finding, including patterns as LIP, NSIP, UIP, COP, bronchiolitis, or diffuse interstitial amyloidosis There is increased prevalence of LIP, seen as extensive areas of ground-glass opacities, nodules, thickening of interlobular septa and thin-walled cysts.
- Airway abnormalities: frequent. Usually bronchial wall thickening, bronchiectasis, bronchiolectasis and air-trapping.
- Lymphoma: increased incidence, usually the B-cell (non-Hodgkin) type, that may arise mainly in the salivary glands, but also from in the stomach and lung. Radiological findings include pulmonary mass, consolidation, mediastinal lymphadenopathy or effusion.
- Pleural effusions: uncommon, tending to occur in association with another immune-mediated disease, such as RA or SLE.
AS is a chronic inflammatory disease of the axial skeleton joints (sacroiliac, costovertebral and apophyseal joints), that occurs more frequently in male patients between 20-30 years-old. Symptoms can initiate with lumbar or gluteal insidious pain accompanied by morning stiffness, which improve with physical activity and return after inactivity.
The diagnosis used to be guided by the modified New York criteria (1984), that are based on the presence of definite radiographic sacroiliitis using plain film (Table 6). In 2009, the Assessment of Spondyloarthritis International Society (ASAS) proposed the new criteria for axial spondyloarthritis (SpA), which includes individuals with chronic (≥ 3 months) back pain, of unknown origin, that began before 45 years old (Table 7).
- Musculoskeletal involvement: more common in sacroiliac joints, rare in the spine without sacroiliac joint involvement. Thoracic findings consist of symmetrical syndesmophytes (“bamboo spine”), usually associated to apical fibrosis and fusion of the costovertebral joints, resulting in chest wall restriction.
- Pleuropulmonary involvement: rare, usually in advanced stages, manifesting most frequently with upper lobe fibrosis.
- Cavities colonized by Aspergillus species: a life-threatening complication, manifesting with hemoptysis.
- Other findings: bronchiectasis, paraseptal emphysema, tracheobronchomegaly, and mediastinal lymph node enlargement.
PM and DM are subtypes of the idiopathic inflammatory myopathies, which are a group of systemic autoimmune disorders characterized by skeletal muscle weakness. Overall, they occur more commonly in females, and affect both children and adults. PM and DM are distinct entities, although related in various clinical and serological features, presenting as subacute progressive and symmetric muscle weakness. The difference between them is basically a characteristic rash that is seen in DM. PM as an isolated disease is very rare, occurring in combination with a systemic autoimmune disease or with a viral or bacterial infection. It is important to emphasize the existence of a clinical subtype of DM of which there is minimal muscle disease or no evidence of inflammatory myopathy. This subset, known as amylopathic dermatomyositis (or dermatomyositis sine myositis), presents a higher chance of progression to pneumomediastinum, which increases the mortality rates.
Diagnosis is suspected by characteristic clinical features, such as muscle weakness, and is confirmed by elevated muscle enzymes (creatinine kinase, lactate dehydrogenase, aldolase), myopathic features on electromyography, and muscle biopsy.
- Aspiration pneumonia: secondary to pharyngeal muscle weakness (most common finding).
- Respiratory muscles involvement: diaphragmatic elevation, reduced lung volumes, and basilar atelectasis, leading to hypoventilation and respiratory failure.
- Interstitial lung disease: correlated with anti–Jo-1 antibodies, often preceding myopathy or occurring in early disease, showing most frequently the NSIP and COP patterns, that can be seen in the same patient.
- Pulmonary fibrosis: fine reticular pattern of the lung bases that progresses to a coarse reticulonodular pattern and honeycombing.
- Subcutaneous calcifications: in DM, sometimes extruding on the skin and causing ulcerations and infections.
- Increased risk for malignancies: most commonly lung cancers.
Mixed Connective Tissue Disease
MCTD is an overlap syndrome with clinical features commonly seen in SLE, SSc, DM/PM or RA, characterized by the presence of high titers of autoantibodies to U1-ribonucleoprotein (U1-RNP). Characteristically it presents with Raynaud’s phenomenon, "puffy fingers" and myalgia, gradually developing features of SSc or skin rashes suggestive of SLE or DM. Other manifestations include arthralgia, pulmonary involvement, esophageal dysmotility, pericarditis, and renal disease. It is still controversial if MCTD is a truly distinct entity or if it is a subset of SLE or SSc.
- Interstitial lung disease: most common pulmonary manifestation. NSIP is the most frequent pattern, followed by UIP and LIP.
- Pulmonary arterial hypertension: clinically most significant finding.
- Esophageal motor impairment: can cause aspiration pneumonia.
- Pleural thickening or effusion.
- Other findings: pulmonary vasculitis, thromboembolism, alveolar hemorrhage, and respiratory muscle dysfunction.
The Vasculitis Syndromes
The diagnosis of vasculitis can be considered in patients with unexplained systemic illness. However, there are some clinical abnormalities that suggest these conditions, such as pulmonary infiltrates and microscopic hematuria, chronic inflammatory sinusitis, palpable purpura, mononeuritis multiplex, unexplained ischemic events and glomerulonephritis with multisystem disease. The first step in the diagnosis is to exclude other diseases that can have clinical manifestations similar to vasculitis. Then, in most cases, biopsying the involved tissue is usually the better way to establish the diagnosis.
Granulomatosis with Polyangiitis (Wegener’s)
GPA, formerly known as Wegener Granulomatosis, is a granulomatous vasculitis with upper and lower airway involvement and glomerulonephritis. The disease occurs has no age or sex predilection. It is considered one of the ANCA-associated vasculitides, along with Microscopic Polyangitis and Churg-Strauss Syndrome.
Diagnosis can be made by a combination of clinical and laboratory findings and demonstration of necrotizing granulomatous vasculitis on tissue biopsy. Diagnostic criteria established by the American College of Rheumatology qualify the patient to have GPA when there are at least 2 of the 4 criteria listed on Table 8.
- Pulmonary nodules and masses: single or multiple (usually <10 lesions), from a few millimeters to over 10 cm in size, often with a random distribution, with central cavitation in up to 50% of cases, usually irregularly marginated and with thick walls, and can result in a scar or resolve completely after treatment.
- Ground-glass opacity and consolidation: may result from pulmonary hemorrhage or infection, often with bilateral perihilar and peribronchovascular distributions, but can also appear with diffuse distribution.
- Airway involvement: second most frequent thoracic manifestation, seen as smooth or nodular thickening of tracheal or bronchial walls, usually focal and circumferential, always involving the posterior membrane of the trachea, and often showing stenosis and calcifications.
- Pleural involvement: unilateral or bilateral effusions that vary in size, reflecting primary pleural involvement, or being resultant from renal failure. Fibrinous pleuritis may be seen adjacent to nodular infammatory lesions. Other manifestations are rare, such as pleural thickening, nodularity, and pneumothorax, and may be associated with infection or malignancy.
- Mediastinal involvement: reactive lymphadenopathy is uncommon, and usually involves the paratracheal and hilar nodes.
- Cardiac involvement: rare finding.
- Pulmonary infarcts.
The disease affects males slightly more frequently, with the mean age of onset around 57 years of age. It shares similar clinical features whit GPA, because of its predilection for small vessels, and is also strongly ANCA-associated. Diagnosis is based on characteristic clinical features of multisystem disease, along with histologic evidence of vasculitis or pauci-immune glomerulonephritis.
- Diffuse alveolar hemorrhage (capillaritis): the most common manifestation, imaging findings identical to other causes.
Eosinophilic Granulomatosis with Polyangitis (Churg-Strauss)
This condition affects males slightly more often than females, and can occur at any age, with possible exception in children. Clinical manifestations are nonspecific, such as fever, malaise, anorexia, and weight loss. The pulmonary involvement is the most common feature, seen as asthmatic attacks and pulmonary infiltrates. Serological eosinophilia is another important finding, showing more than 1000 cells/μL in most patients. To reach the diagnosis, there must be evidence of asthma, peripheral blood eosinophilia, and clinical findings consistent with vasculitis.
- Bilateral areas of ground-glass opacity or consolidation: most common lung finding, usually with a peripheral and symmetric distribution.
- Interlobular septal thickening: relatively common.
- Pleural effusions.
- Other findings: bronchial wall thickening, diffuse reticular pattern or small and large nodular opacities that can cavitate.
Occurs more frequently in adolescent girls and young women, and affects more often asians, although it is not racially or geographically restricted. Clinical features are related to vascular compromise and organ ischemia. Diagnosis is suspected in young woman with decreased or absent peripheral pulses, discrepancies in blood pressure, and arterial bruits, and is confirmed by the characteristic pattern on arteriography: irregular vessel walls, stenosis, poststenotic dilation, aneurysm formation, occlusion and increased collateral circulation.
- Involvement of the aortic arch and its branches: more commonly at the origin of the subclavian artery, resulting in arm claudication and Raynaud’s phenomenon. Also affects the common carotid artery (58%), aortic arch and vertebral artery (35%), pulmonary artery (10-40%), and rarely the coronary arteries (<10%).
Multisystemic disorder that presents with recurrent oral and genital aphthous ulcerations, and eye involvement, with scarring and bilateral panuveitis. There are no specific clinical, histologic, laboratory findings; however, the diagnosis is based on characteristic clinical manifestations, included in the internationally agreed diagnostic criteria.
- Pulmonary artery aneurysm: most commonly caused by Behçet’s Disease, can be fusiform to saccular, often multiple and bilateral, located in the lower lobe or main pulmonary arteries. May rupture and erode into a bronchus, causing hemoptysis. 30% of patients with die within 2 years.
- Thickening of vessel walls: can be seen in the aorta and superior vena cava (SVC), due to vasculitis.
- Pulmonary infarcts, atelectasis and hemorrhage: subpleural alveolar infiltrates and wedge-shaped or ill-defined rounded areas of increased opacity, which represent focal vasculitis with hemorrhage, infarction, and inflammation.
- Pulmonary embolism: rare complication secondary to superficial or deep peripheral vein thrombosis.
- SVC thrombosis: usually accompanied by thrombosis of other mediastinal veins.
- Interstitial lung disease: COP, eosinophilic pneumonia, recurrent pneumonia, bronchitis, fibrosis and/or emphysema.
- Pleural involvement: nodules and effusion.
- Mediastinal lymphadenopathy.
- Intracardiac thrombosis: more frequently in the right side of the heart.
- Pericardial effusion.
- Aortic arch, subclavian and coronary arteries aneurysms.
Thematically related posters
ECR 2018 / C-0963
The different faces of Pneumocystis jiroveci pneumonia in AIDS patients: HRCT imaging spectrum
ECR 2018 / C-1337
Evaluation of deformable image registration using diffeomorphic transformation models for three-dimensional temporal subtraction of chest tomography images