Systemic Sclerosis Imaging
No Results
No Results
processing….
Systemic sclerosis is a multisystem disease of connective tissue that is accompanied by vasculopathy. Scleroderma, its original name, means hard skin.
Progressive systemic sclerosis (PSS) is a connective tissue disease associated with small vessel arterial vasculopathy and inflammatory and immunologic processes. The peak incidence is between 45 and 64 years of age. [1, 2]
Clinically, PSS is classified as diffuse or limited depending on the distribution of skin disease. PSS is considered limited when involvement is restricted to the distal extremities and face. The limited form is associated with a lower risk of visceral involvement, although pulmonary hypertension is more common. [3, 4, 5, 6] (See the images below.)
Diffuse cutaneous systemic sclerosis (dcSSc) and limited cutaneous systemic sclerosis (lcSSc) scleroderma overlap the following syndromes [7] :
CREST syndrome (calcinosis, Raynaud phenomenon, esophageal dysmotility, skin pigmentation, telangiectasias)
Mixed connective tissue disease (controversial whether this is a separate entity or an intermediate stage in the progression to connective tissue disease)
Scleromyositis (coexisting features of dermatomyositis without features of systemic lupus erythematosus)
Polymyositis synthetase (interstitial lung disease, myositis, Raynaud phenomenon, arthritis)
Morphea (focal cutaneous scleroderma)
Chest radiography is insensitive, since findings are abnormal in only two thirds of patients with pulmonary disease.
High-resolution computed tomography (HRCT) scanning is the best imaging test for assessing the extent and severity of pulmonary disease. Reported detection of fibrosis with HRCT is 60-90%, compared with 60-100% at autopsy. [8, 9, 10, 11, 12, 1, 13, 14] HRCT findings are abnormal in most patients with functional impairment. False-negative HRCT imaging study findings have occurred in the setting of alveolitis, as documented by Remy-Jardin et al using bronchoalveolar lavage in patients with normal pulmonary function tests. [15] Echocardiographic measurements of systolic pulmonary arterial pressure correlate well with right heart catheterization values. [16]
Radiographs in women who are pregnant are limited to a single PA view to minimize radiation exposure. Shielding is used when appropriate. If HRCT examination is considered essential during pregnancy, it can be tailored to minimize radiation exposure.
A collaborative approach between pulmonologists and thoracic radiologists is important in the diagnosis and management of interstitial lung disease. Analysis of HRCT images of the chest can guide video-assisted thoracoscopic lung biopsy. An increased incidence of lung cancer is seen in patients with scleroderma, and the radiologist is involved in detection and diagnosis through CT-guided percutaneous lung biopsy.
Perform percutaneous drainage of complicated parapneumonic effusions and empyemas with CT or ultrasonographic guidance.
Early radiographic findings include subpleural reticular or reticulonodular opacity in a basal predominant distribution. (See the image below.)
Late radiographic findings include the following:
Fibrotic changes involving the lower two thirds of the lung, with associated volume loss and honeycombing
Pulmonary artery enlargement and cardiomegaly
Ancillary findings include diffuse esophageal dilation with a resultant “air esophagram sign,” which is useful when present to differentiate progressive systemic sclerosis (PSS) from idiopathic pulmonary fibrosis (IPF), asbestosis, and rheumatoid arthritis.
Chest radiography is relatively insensitive in early disease, and findings may be minimal even in advanced disease; however, chest radiographic findings are observed in as many as two thirds of symptomatic patients, with findings suggestive of fibrosis demonstrated in 25-45% of patients. (See the image below.)
Interstitial lung disease with a predominant lower lobe distribution on chest radiography may have numerous etiologies, including PSS. Clinical history and esophageal dilation on radiographs suggest PSS. Any phase of IPF, asbestosis, interstitial pulmonary edema, lymphangitic metastases, pulmonary hemorrhage, and other diffuse lung diseases may mimic PSS on chest radiographs. On the posteroanterior (PA) view, the breast shadows can mimic increased markings over the lower lung zones. Lateral view is critical so as to obtain a less obscured view of the lower lobes.
Patients with suggested or known diagnosis of PSS should undergo the following examinations [17] :
Standard resolution CT (SRCT) to exclude a lung neoplasm (which is slightly more common than in the general population) and to evaluate pleuropericardial, esophageal, cardiac, and pulmonary arterial abnormalities
HRCT to evaluate lung parenchymal involvement
Pulmonary fibrosis and pulmonary hypertension are the most common findings. Overlap syndromes or CREST syndrome are suggested when pulmonary hypertension is out of proportion to the degree of fibrosis.
HRCT findings of pulmonary fibrosis include the following:
Architectural distortion
Subpleural cysts or honeycombing
Irregular reticular opacities (seen in the image below)
Interlobular septal thickening
Traction bronchiectasis (seen in the image below) and bronchiolectasis
Visceral pleural thickening
Parenchymal micronodules
Ground-glass opacity may indicate acute inflammation (alveolitis). Honeycombing (demonstrated in the image below) favors a histologic usual interstitial pneumonitis (UIP) pattern.
Mixed reticulation and ground-glass opacity with little or absent honeycombing favor histologic nonspecific interstitial pneumonia (NSIP).
Fibrosis is subpleural and basal predominant.
A less marked involvement of the upper lobes favors PSS or other collagen vascular disease as the etiologic cause of the UIP pattern, rather than IPF or chronic hypersensitivity pneumonitis.
HRCT identified fibrotic interstitial lung disease (ILD) in 16 of 43 patients with systemic sclerosis. The main pattern of ILD was identified with nonspecific interstitial pneumonia (NSIP). [13]
Mediastinal adenopathy is found; the prevalence is increased in more extensive lung disease. Esophageal dilation is present on CT scans in 80% of patients with diffuse lung disease resulting from PSS.
Studies have shown that HRCT is diagnostically accurate in specific subsets of patients with diffuse lung disease. In a study of 85 patients with diffuse lung disease by Swensen et al, [18] radiologists more frequently had a high level of confidence in diagnosing UIP than any other pattern and listed it as the number one diagnosis in 89% of patients with that histologic finding. Imaging diagnoses were most accurate (90% correct) when a high level of confidence was present.
Remy-Jardin and colleagues correlated HRCT findings with functional parameters and bronchoalveolar lavage (BAL) results in patients with PSS. [15] BAL findings were abnormal in 7 of 21 patients with normal imaging and PFTs, suggesting that it is more sensitive than HRCT in detecting subclinical alveolitis. The extent of parenchymal destruction, which correlated with functional abnormality, was better depicted by HRCT.
Diot and colleagues assigned point values to each abnormal finding present on HRCT of 52 patients with progressive systemic sclerosis (PSS). [8] Total scores were inversely proportional to total lung capacity and diffusing capacity for carbon monoxide (DLCO). Receiver operator curve analysis demonstrated that an HRCT score of 7 or greater minimized false negatives (sensitivity of 0.60) while achieving a specificity of 0.83. The positive predictive value of HRCT in this study was 0.82.
False negatives have been documented by Remy-Jardin et al in patients with subclinical alveolitis. [15]
Al-Jahdali H, Rajiah P, Allen C, Koteyar SS, Khan AN. Pictorial review of intrathoracic manifestations of progressive systemic sclerosis. Ann Thorac Med. 2014 Oct. 9 (4):193-202. [Medline].
Yaqub A, Chung L. Epidemiology and risk factors for pulmonary hypertension in systemic sclerosis. Curr Rheumatol Rep. 2013 Jan. 15 (1):302. [Medline].
van Laar JM, Stolk J, Tyndall A. Scleroderma lung: pathogenesis, evaluation and current therapy. Drugs. 2007. 67(7):985-96. [Medline].
Antoniou KM, Wells AU. Scleroderma lung disease: evolving understanding in light of newer studies. Curr Opin Rheumatol. 2008 Nov. 20(6):686-91. [Medline].
Liu T, McCalmont TH, Frieden IJ, Williams ML, Connolly MK, Gilliam AE. The stiff skin syndrome: case series, differential diagnosis of the stiff skin phenotype, and review of the literature. Arch Dermatol. 2008 Oct. 144(10):1351-9. [Medline].
Leslie KO, Trahan S, Gruden J. Pulmonary pathology of the rheumatic diseases. Semin Respir Crit Care Med. 2007 Aug. 28(4):369-78. [Medline].
Phillips K, Byrne-Dugan C, Batterson E, Seibold JR. Rapidly progressive fatal interstitial lung disease in a patient with systemic sclerosis. Nat Rev Rheumatol. 2009 Apr. 5 (4):225-8. [Medline].
Diot E, Boissinot E, Asquier E, et al. Relationship between abnormalities on high-resolution CT and pulmonary function in systemic sclerosis. Chest. 1998 Dec. 114(6):1623-9. [Medline].
Devenyi K, Czirjak L. High resolution computed tomography for the evaluation of lung involvement in 101 patients with scleroderma. Clin Rheumatol. 1995 Nov. 14(6):633-40. [Medline].
Pignone A, Matucci-Cerinic M, Lombardi A, et al. High resolution computed tomography in systemic sclerosis. Real diagnostic utilities in the assessment of pulmonary involvement and comparison with other modalities of lung investigation. Clin Rheumatol. 1992 Dec. 11(4):465-72. [Medline].
Wells AU, Hansell DM, Corrin B, et al. High resolution computed tomography as a predictor of lung histology in systemic sclerosis. Thorax. 1992 Sep. 47(9):738-42. [Medline].
Steele R, Hudson M, Lo E, Baron M. Clinical decision rule to predict the presence of interstitial lung disease in systemic sclerosis. Arthritis Care Res (Hoboken). 2012 Apr. 64(4):519-24. [Medline].
Zompatori M, Leone MB, Giannotta M, Galiè N, Palazzini M, Reggiani ML, et al. Pulmonary hypertension and systemic sclerosis: the role of high-resolution computed tomography. Radiol Med. 2013 Dec. 118 (8):1360-72. [Medline].
Rabinovich CE. Challenges in the diagnosis and treatment of juvenile systemic sclerosis. Nat Rev Rheumatol. 2011 Oct 11. 7 (11):676-80. [Medline].
Remy-Jardin M, Remy J, Wallaert B, et al. Pulmonary involvement in progressive systemic sclerosis: sequential evaluation with CT, pulmonary function tests, and bronchoalveolar lavage. Radiology. 1993 Aug. 188(2):499-506. [Medline].
Denton CP, Cailes JB, Phillips GD, et al. Comparison of Doppler echocardiography and right heart catheterization to assess pulmonary hypertension in systemic sclerosis. Br J Rheumatol. 1997 Feb. 36(2):239-43. [Medline].
Kim HJ, Li G, Gjertson D, Elashoff R, Shah SK, Ochs R, et al. Classification of parenchymal abnormality in scleroderma lung using a novel approach to denoise images collected via a multicenter study. Acad Radiol. 2008 Aug. 15(8):1004-16. [Medline].
Swensen SJ, Aughenbaugh GL, Myers JL. Diffuse lung disease: diagnostic accuracy of CT in patients undergoing surgical biopsy of the lung. Radiology. 1997 Oct. 205(1):229-34. [Medline].
Tracy Elliot, MD, HBSc, FRCPC Assistant Professor, Department of Radiology, University of Alberta Faculty of Medicine and Dentistry, Canada
Tracy Elliot, MD, HBSc, FRCPC is a member of the following medical societies: Alberta Medical Association, Canadian Association of Radiologists, Radiological Society of North America, Royal College of Physicians and Surgeons of Canada, Society of Thoracic Radiology
Disclosure: Nothing to disclose.
Bernard D Coombs, MB, ChB, PhD Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.
Eugene C Lin, MD Attending Radiologist, Teaching Coordinator for Cardiac Imaging, Radiology Residency Program, Virginia Mason Medical Center; Clinical Assistant Professor of Radiology, University of Washington School of Medicine
Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear Medicine, American College of Radiology, Radiological Society of North America, Society of Nuclear Medicine and Molecular Imaging
Disclosure: Nothing to disclose.
Judith K Amorosa, MD, FACR Clinical Professor of Radiology and Vice Chair for Faculty Development and Medical Education, Rutgers Robert Wood Johnson Medical School
Judith K Amorosa, MD, FACR is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America, Society of Thoracic Radiology
Disclosure: Nothing to disclose.
Systemic Sclerosis Imaging
Research & References of Systemic Sclerosis Imaging|A&C Accounting And Tax Services
Source
0 Comments