HRCT OF IDIOPATHIC INTERSTITIAL PNEUMONIAS Disclosures Genentech, Inc. Speakers Bureau Tadashi Allen, MD University of Minnesota Assistant Professor Diagnostic Radiology 10/29/2016 Outline Definition of Terms: Lexicon Definition of Terms Non-Infectious Interstitial Lung Diseases: Idiopathic Interstitial Pneumonias Systemic Autoimmune Disease Hypersensitivity Pneumonitis Sarcoidosis Cystic Fibrosis Radiation Pneumonitis Drug Toxicity Emphysemas Pneumoconioses Langerhans Cell Histiocytosis Lymphangioleiomyomatosis Lymphangitic Carcinomatosis Amyloidosis Chemical Pneumonitis Ground Glass Opacity Traction Bronchiectasis Honeycombing Reticular Pattern Nodular Pattern Cysts Interlobular Septal Thickening Consolidation Ground Glass Opacity: Example Traction Bronchiectasis: Example Traction Bronchiectasis 1-2 mm cuts. 42 y/o female with PJP. Traction bronchiectasis refers to bronchial dilation due to fibrosis 1
Honeycombing: Example Honeycombing 5: 91% 3: 63% Honeycombing 2 4: 58% Honeycombing clustered air-filled, thick walled cysts 69 yo male, with UIP/IPF 5, definite honeycombing; 4, probable honeycombing; 3, possible honeycombing; 2, probably no honeycombing; 1, definitely no honeycombing Watadani et al. Radiology: Volume 266: Number 3 March 2013 1: 95% Interobserver variability honeycombing Reticular Pattern: Example Nodular Pattern: Example Cysts: Example Nodular pattern 29 y/o female with pulmonary Langerhan s Cell Histiocytosis 2
Interlobular septal thickening Interlobular septal thickening 49 y/o female with lymphangioleiomyomatosis 86 y/o female short of breath Consolidation: Example Areas of consolidation 30 y/o male influenza pneumonia with organizing pneumonia pattern Usual Interstitial Pneumonia (UIP): Idiopathic Pulmonary Fibrosis (IPF) is description of clinical entity associated with morphologic pattern of UIP Poor prognosis CT features: Reticular pattern Basal/peripheral predominance (apical basilar gradient) Honeycombing Traction bronchiectasis Architectural distortion Ground glass common but less predominant IPF or UIP Incidence: 6.8-16.3 per 100,000 persons based on health care claims in a large US health plan Prevalence: 14-42 per 100,000 persons Etiology: Unknown Risk factors: smoking strong risk factor (esp.>20 py) Environmental exposures Microbial agents GERD Genetic factors 3
IPF: Diagnosis ATS-ERS-JRS-ALAT 2000 consensus no longer valid ATS-ERS-JRS-ALAT 2011 IPF Idiopathic Pulmonary Fibrosis Major Criteria Exclusion of other known causes of ILD, such as certain drug toxicities, environmental exposures, and connective tissue diseases Abnormal pulmonary function studies that include evidence of restriction (reduced VC often with an increased FEV1/FVC ratio) and impaired gas exchange [increased AaPO2 with rest or exercise or decreased DLCO] Bibasilar reticular abnormalities with minimal ground glass opacities on HRCT scans Transbronchial lung biopsy or bronchoalveolar lavage (BAL) showing no features to support an alternative diagnosis Am J Respir Crit Care Med Vol 161. pp 646 664, 2000 Internet address: www.atsjournals.org Minor Criteria Age. 50 yr Insidious onset of otherwise unexplained dyspnea on exertion Duration of illness > 3 mo Bibasilar, inspiratory crackles (dry or Velcro type in quality) Chronic progressive fibrosing interstitial pneumonia idiopathic. Occurs in older adults Limited to the lungs Associated with histopathologic and radiologic pattern of UIP UIP Diagnosis requires: UIP Diagnosis Exclusion of other known causes of ILD including domestic and occupational exposures, connective tissue disease, and drug induced lung toxicity UIP pattern on HRCT without a surgical biopsy Specific HRCT and biopsy patterns Accuracy increases with multidisciplinary discussion between Pulmonologists Radiologists Pathologists (Whom are experienced in the diagnosis of ILD.) UIP or IPF types of progression Increased respiratory symptoms Worsening PFTs Progressive fibrosis on HRCT Acute respiratory decline Death UIP or IPF may have comorbid conditions including: Pulmonary hypertension GERD Obstructive sleep apnea Obesity Emphysema 4
UIP: CT Imaging 1 UIP: CT Imaging 2 53 y/o female biopsy proven UIP diagnosis IPF Possible UIP pattern on CT given lack of honeycombing. Biopsy UIP pattern. Dx IPF UIP: CT Imaging 3 UIP: ATS 2011 HRCT Criteria UIP: Extensive interstitial fibrosis with ground glass opacification and honeycombing Am J Respir Crit Care Med Vol 183. pp 788 824, 2011 UIP: ATS 2011 HRCT Multidisciplinary Discussion Am J Respir Crit Care Med Vol 183. pp 788 824, 2011 Am J Respir Crit Care Med Vol 183. pp 788 824, 2011 5
IPF Diagnostic algorithm Natural history of IPF Rx IPF: Lung transplant 11/2013 2/2009 56 y/o male with IPF NSIP: Clinical Features Female to male ratio 2:1 5 yr survival 82.3% 2 subtypes: cellular and fibrotic Fibrotic NSIP accounts for most of the mortality (8:1) Cough; Median duration 6 months Dyspnea; Median duration 7 months Prognosis is variable. NSIP Occurs as idiopathic condition No longer provisional diagnosis Can occur in variety of settings such as: Collagen vascular disease Hypersensitivity pneumonitis Drug toxicity Am J Respir Crit Care Med Vol 177. pp 1338 1347, 2008 Am J Respir Crit Care Med Vol 177. pp 1338 1347, 2008 6
Cellular NSIP: CT Imaging Fibrotic NSIP: CT Imaging 54 y/o female cellular NSIP 31 y/o male with fibrotic NSIP NSIP: Additional Imaging NSIP: Additional imaging NSIP: Reversibility with Treatment NSIP post treatment 7 months f/u NSIP pretreatment 7
RB-ILD: Features 1 RB-ILD: Features 2 Histologic respiratory bronchiolitis is in 100% of cigarette smokers When symptomatic, becomes RB-ILD Most have mild symptoms, but some with severe hypoxemia, cough Average smoking hx is 30 pack years Patients are usually age 3 rd or 4 th decade Disease reversible with smoking cessation and steroids CT Characteristics Imaging pattern similar to hypersensitivity pneumonitis Centrilobular ground glass nodularity Upper and mid-lung predominance RB-ILD: CT Imaging 1 RB-ILD: CT Imaging 2 58 y/o male RB-ILD Same pt RB-ILD CT Imaging 3 Same pt 8
DIP: Features DIP: CT Imaging 1 Primarily smoking related dz but is well described in nonsmokers Some are related to extension of childhood DIP related to surfactant protein gene mutation Survival: 70% at 10yrs Can improve with steroids and smoking cessation Not end spectrum of RB-ILD. Desquamative is misnomer (Liebow and Carrington); characterized by macrophages filling alveoli. They considered to call alveolar macrophage pneumonia. 43 y/o female DIP DIP: CT Imaging 2 DIP: CT Imaging 3 51 yo DIP Mortality Lynch DA, et al. Idiopathic interstitial pneumonias: CT features. Radiology 2005; 236: 10-21 9
(COP) Cryptogenic Organizing Pneumonia Histologic pattern is organizing pneumonia Formerly referred to as (BOOP) bronchiolitis obliterans organizing pneumonia Often confused with constrictive bronchiolitis (obliterative bronchiolitis), an airway disease. (COP) Clinical features Age: mean 55 No gender predilection Mild dyspnea, cough, fever over a few weeks Respiratory tract infection can precede symptoms along with antibiotic rx. Or may be in CVD, or drug induced Very responsive to corticosteroids although relapses are frequent by 3 months COP Atoll 47 yo female on MTx for RA 4 months apart Google images: Taiaro Atoll, French Polynesia, Pacific Ocean COP: CT Imaging 2 CT Imaging 2 32 yo AML COP and atoll sign Same pt 10
(AIP) Acute Interstitial Pneumonia acute onset of symptoms Age: mean 50 years severe dyspnea with need for mechanical ventilation h/o viral-like illness exists Cigarette smoking not contributory Treatment is supportive (AIP) Clinical Features (AIP) Imaging features Corticosteroids are effective in the early phase Prognosis is poor Mortality of 50% or more Most patients who survive the acute phase progress to lung fibrosis Radiographic and HRCT findings are similar to ARDS AIP patients more likely to have symmetric, bilateral distribution with lower lobe predominance. (AIP) Imaging Features Ground-glass (AIP) Exudative phase 22- year-old Mild bronchial dilation GGO GGO consolidation consolidation RadioGraphics 2007; 27:595 615 11
Fibrotic phase AIP 62 yo male AIP (LIP) Clinical Features (LIP) Imaging Features Affects women more than men 5 th decade of life Slowly progressive dyspnea and cough Occasionally fever, night sweats weight loss. small percentage transform to malignant lymphoma HRCT: Diffuse or lower lung predominance ground-glass opacity, related to interstitial inflammation Perivascular cysts: mid lung zones and result from air trapping due to peribronchiolar cellular infiltration Centrilobular nodules and septal thickening LIP: CT Imaging 1 LIP: CT Imaging 2 52 yo female LIP and PCKD 61 yo female Sjogren s, LIP 12
Pleuroparenchymal Fibroelastosis High mortality 40% Upper lung predominant Disease progression 60% Collagen vascular diseases Hypersensitivity Pneumonitis: Features Also called extrinsic allergic alveolitis Caused by repeated exposure to organic and chemical antigens Pathogenesis: cell-mediated immunity (specifically T-helper cells) Diagnosis: history of exposure, clinical signs/sxs, radiologic abnormalities, and histopathology HP: Etiology HP: Radiographic Manifestations HRCT: Poorly defined centrilobular nodules (<5mm) predominantly in lower lobes Ground glass opacification Fibrosis: irregular linear opacities, traction bronchiectasis, honeycombing Emphysema Air-trapping Radiographics 2009, November. Issue 13
HP: CT Imaging 1 HP: CT Imaging 2 Acute Fibrinous Organizing pneumonia Can be idiopathic, or occur in CVD, HP, or drug reaction, or with eosinophilic pneumonia. HRCT findings of bibasilar opacities and consolidation. Within the clinical spectrum between DAD, and OP. Acute Fibrinous Organizing pneumonia Summary END IIPs are classified based on histologic criteria, but correlate with imaging findings In many cases, final diagnosis requires a multidisciplinary approach between clinicians, radiologists and pathologists HRCT is indicated in all patients with IIP UIP must be differentiated from all other IIPs because of its markedly poorer prognosis 14