CONTENTS
- Peripheral vs. central
- Peribronchovascular
- Upper vs. lower
- Migratory infiltrates
- Distribution of bronchiectasis ➡️
- Questions & discussion
abbreviations used in the pulmonary section:
- AE-ILD: Acute exacerbation of ILD 📖
- AIP: Acute interstitial pneumonia (Hamman-Rich syndrome) 📖
- ANA: Antinuclear antibody 📖
- ANCA: Antineutrophil cytoplasmic antibodies 📖
- ARDS: Acute respiratory distress syndrome 📖
- ASS: Antisynthetase Syndrome 📖
- BAL: Bronchoalveolar lavage 📖
- BiPAP: Bilevel positive airway pressure 📖
- COP: Cryptogenic organizing pneumonia 📖
- CPAP: Continuous positive airway pressure 📖
- CPFE: Combined pulmonary fibrosis and emphysema 📖
- CTD-ILD: Connective tissue disease associated interstitial lung disease 📖
- CTEPH: Chronic thromboembolic pulmonary hypertension 📖
- DAD: Diffuse alveolar damage 📖
- DAH: Diffuse alveolar hemorrhage 📖
- DIP: Desquamative interstitial pneumonia 📖
- DLCO: Diffusing capacity for carbon monoxide 📖
- FEV1: Forced expiratory volume in 1 second 📖
- FVC: Forced vital capacity 📖
- GGO: Ground glass opacity 📖
- GLILD: Granulomatous and lymphocytic interstitial lung disease 📖
- HFNC: High flow nasal cannula 📖
- HP: Hypersensitivity pneumonitis 📖
- IPAF: Interstitial pneumonia with autoimmune features 📖
- IPF: Idiopathic pulmonary fibrosis 📖
- IVIG: Intravenous immunoglobulin 📖
- LAM: Lymphangioleiomyomatosis 📖
- LIP: Lymphocytic interstitial pneumonia 📖
- MCTD: Mixed connective tissue disease 📖
- NIV: Noninvasive ventilation (including CPAP or BiPAP) 📖
- NSIP: Nonspecific interstitial pneumonia 📖
- NTM: Non-tuberculous mycobacteria 📖
- OP: Organizing pneumonia 📖
- PAP: Pulmonary alveolar proteinosis 📖
- PE: Pulmonary embolism 📖
- PFT: Pulmonary function test 📖
- PLCH: Pulmonary Langerhans Cell Histiocytosis 📖
- PPFE: Pleuroparenchymal fibroelastosis 📖
- PPF: Progressive pulmonary fibrosis 📖
- PVOD/PCH Pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis 📖
- RB-ILD: Respiratory bronchiolitis-associated interstitial lung disease 📖
- RP-ILD: Rapidly progressive interstitial lung disease 📖
- TNF: tumor necrosis factor
- UIP: Usual Interstitial Pneumonia 📖
disorders that may have a peripheral distribution
- Most eosinophilic pneumonias:
- CEP (chronic eosinophilic pneumonia).
- EGPA (eosinophilic granulomatosis with polyangiitis)(consolidations tend to have a lobular distribution, often associated with centrilobular nodules). (29286851)
- Simple pulmonary eosinophilia.
- HES (hypereosinophilic syndrome).
- OP (organizing pneumonia).
- Sarcoidosis.
- Drug-induced pneumonia (e.g., amiodarone).
- Emboli:
- Infarct due to PE (pulmonary embolism).
- Septic pulmonary embolism.
- Silicone embolism syndrome.
- Diffuse ILDs (most interstitial lung diseases have a peripheral distribution):
- IPF (idiopathic pulmonary fibrosis).
- NSIP (nonspecific interstitial pneumonia is usually peripheral, but may also have peripheral sparing).
- DIP (desquamative interstitial pneumonia).
- Asbestosis.
- Pulmonary contusion.
- Lymphomatoid granulomatosis.
- Adenocarcinoma.
- IgG4-related lung disease.
- COVID-19.
radiographic appearance/definition
- Chest X-ray:
- Central distribution is most notable in the perihilar regions. This is often referred to as a “butterfly” or “batwing” distribution.
- Lung apices, costophrenic angles, and periphery may be spared.
- CT scan: Central distribution is most notable due to sparing of the lung periphery.
differential diagnosis
- Certain forms of pulmonary edema:
- Cardiogenic pulmonary edema.
- Neurogenic pulmonary edema.
- Inhalational lung injury, including:
- EVALI (E-cigarette and vaping-associated lung injury).
- Crack lung.
- DAH (diffuse alveolar hemorrhage):
- Tends to be more pronounced centrally.
- Often spares the costophrenic angle, apices, and lung periphery.
- Pneumocystis (may have sparing of the subpleural lung).
- Interstitial lung diseases:
- NSIP (nonspecific interstitial pneumonia may have subpleural sparing in ~20% of patients).
- Organizing pneumonia. (34246383)
- PLCH (pulmonary Langerhans cell histiocytosis often spares the costophrenic angles and tips of the middle lobes)
- Malignancy:
- Lymphoproliferative diseases.
- Lymphangitic carcinomatosis.
- Kaposi sarcoma.
- Therapeutic injection of radioactive Yttrium-labeled microspheres (with embolization to the lungs).(24460448)
- PAP (pulmonary alveolar proteinosis).
basics
- Peribronchovascular distributions result from disease localized to the airways, vasculature, and/or lymphatics.
- ⚠️ Micronodules that are distributed in a peribronchovascular fashion are discussed further here: 📖 The following discussion applies to larger nodules or consolidations arranged in a peribronchovascular distribution.
differential diagnosis of peribronchovascular disease
infection
- Bronchopneumonia:
- Often associated with tree-in-bud abnormalities.
- Note that this can be caused by some viruses (e.g., HSV).
- Further discussion of bronchopneumonia: 📖
- Fungal:
- Airway-invasive aspergillosis.
inflammatory
- OP (organizing pneumonia).
- CEP (chronic eosinophilic pneumonia).
- Sarcoidosis.
- Vasculitis:
- GPA (granulomatosis with polyangiitis).
- EGPA (eosinophilic granulomatosis with polyangiitis).
malignant and/or lymphoproliferative
- Lymphomatoid granulomatosis.
- KS (Kaposi sarcoma).
- Primary pulmonary lymphoma.
- FB/LIP (Follicular bronchiolitis & lymphocytic interstitial pneumonitis).
- Pulmonary adenocarcinoma.
- IgG4-related lung disease.
- Pulmonary leukemic infiltrates.
other
- Inhalational injury.
Additional information: Excellent review article by Ko et al. is available here: 📄 Table 1 and Figure 2 contain some useful algorithms.
Lungs are thicker at the bases, which may tend to cause the bases to appear more diseased. A lateral film may help accurately determine if the upper lung is preferentially involved.
upper lung zone predominant
- Infectious:
- Reactivation tuberculosis.
- Fungus (e.g., chronic histoplasmosis).
- Pneumocystis in a patient who received aerosolized pentamidine.
- Inflammatory:
- Sarcoidosis (& Berylliosis).
- Rheumatoid arthritis (necrobiotic nodular form; may cavitate and mimic infection).(36566029)
- CEP (chronic eosinophilic pneumonia).
- PPFE (pleuroparenchymal fibroelastosis).
- Ankylosing spondylitis.
- Exposure-related:
- HP (hypersensitivity pneumonitis).
- Respiratory bronchiolitis.
- Pneumoconiosis, including:
- Silicosis.
- Coal workers pneumoconiosis.
- “Apical cap” or “pleural cap.” (35680316) – Normal variant that is more common in older patients. Abnormalities are usually restricted to the apical 5 mm. Progression over time is rare.
- Other:
- PLCH (pulmonary Langerhans cell histiocytosis).
- MPC (metastatic pulmonary calcification).
mid-lung predominant
- Sarcoidosis.
- Cardiogenic pulmonary edema.
- Pneumocystis.
lower lung zone predominant
- Interstitial pneumonias:
- IPF (idiopathic pulmonary fibrosis).
- Asbestosis.
- NSIP (nonspecific interstitial pneumonia).
- Connective tissue-related interstitial lung disease.
- DIP (desquamative interstitial pneumonia).
- LIP (lymphoid interstitial pneumonia).
- Aspiration:
- Aspiration pneumonia.
- Aspiration bronchiolitis.
- Lipoid pneumonia.
- Hematogenous:
- Hematogenous metastases.
- Septic emboli.
Causes of infiltrates which appear to migrate over time include:
recurrent, discrete events:
- Recurrent aspiration events.
- Recurrent pneumonias in the context of immunosuppression.
- Recurrent pulmonary emboli causing pulmonary infarction.
repeated components of a single process:
- OP (organizing pneumonia).
- Eosinophilic pneumonia, for example:
- Simple pulmonary eosinophilia: may migrate over a period of days.
- Chronic eosinophilic pneumonia: may migrate over a period of weeks to months.
- Diffuse alveolar hemorrhage (with repeated episodes of bleeding).
- Vasculitis:
- EGPA (eosinophilic granulomatosis with polyangiitis).
- GPA (granulomatosis with polyangiitis).
- HP (hypersensitivity pneumonitis).
- Rare causes:
💡 Infectious consolidations usually take a relatively prolonged time to resolve. Therefore, consolidation which is rapidly migrating argues against an infectious process.
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= Link to FOAMed site with related information.- 📄 = Link to open-access journal article.
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References
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- 23436867 Nemec SF, Bankier AA, Eisenberg RL. Upper lobe-predominant diseases of the lung. AJR Am J Roentgenol. 2013 Mar;200(3):W222-37. doi: 10.2214/AJR.12.8961 [PubMed]
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- 26981938 Saukkonen K, Sharma A, Mark EJ. CASE RECORDS of the MASSACHUSETTS GENERAL HOSPITAL. Case 8-2016. A 71-Year-Old Man with Recurrent Fevers, Hypoxemia, and Lung Infiltrates. N Engl J Med. 2016 Mar 17;374(11):1077-85. doi: 10.1056/NEJMcpc1505680 [PubMed]
- 29286851 Chaddha U, Lee C. Subacute Respiratory Illness with Peripheral Pulmonary Opacities. Ann Am Thorac Soc. 2018 Jan;15(1):107-109. doi: 10.1513/AnnalsATS.201708-659CC [PubMed]
- 31200868 Ko JP, Girvin F, Moore W, Naidich DP. Approach to Peribronchovascular Disease on CT. Semin Ultrasound CT MR. 2019 Jun;40(3):187-199. doi: 10.1053/j.sult.2018.12.002 [PubMed]
- 36566029 Bhardwaj A, Ghosh S, Stoller JK. Radiographic Distribution as a Diagnostic Clue in Pulmonary Disease. Respir Care. 2023 Jan;68(1):151-166. doi: 10.4187/respcare.10210 [PubMed]
Books:
- Shah, P. L., Herth, F. J., Lee, G., & Criner, G. J. (2018). Essentials of Clinical pulmonology. In CRC Press eBooks. https://doi.org/10.1201/9781315113807
- Shepard, JO. (2019). Thoracic Imaging The Requisites (Requisites in Radiology) (3rd ed.). Elsevier.
- Walker C & Chung JH (2019). Muller’s Imaging of the Chest: Expert Radiology Series. Elsevier.
- Palange, P., & Rohde, G. (2019). ERS Handbook of Respiratory Medicine. European Respiratory Society.
- Rosado-De-Christenson, M. L., Facr, M. L. R. M., & Martínez-Jiménez, S. (2021). Diagnostic imaging: chest. Elsevier.
- Murray & Nadel: Broaddus, V. C., Ernst, J. D., MD, King, T. E., Jr, Lazarus, S. C., Sarmiento, K. F., Schnapp, L. M., Stapleton, R. D., & Gotway, M. B. (2021). Murray & Nadel’s Textbook of Respiratory Medicine, 2-Volume set. Elsevier.
- Fishman's: Grippi, M., Antin-Ozerkis, D. E., Cruz, C. D. S., Kotloff, R., Kotton, C. N., & Pack, A. (2023). Fishman’s Pulmonary Diseases and Disorders, Sixth Edition (6th ed.). McGraw Hill / Medical.
