Diagnosis of ILDs 

Differential diagnosis of ILDs can be challenging due to overlapping clinical, radiological and pathological presentations1,2

ILD patients with the HRCT scans in their hands.


Example of a multidisciplinary team

A multidisciplinary team including a pulmonologist, radiologist and histopathologist should be involved in ILD diagnosis

It is recommended that all collected diagnostic information be evaluated by a multidisciplinary team experienced in ILD, which may either establish a diagnosis or discuss the indication for further diagnostic procedures such as thoracoscopic lung biopsy or transbronchial cryobiopsy.7

Weighing diagnostic yield against potential risks associated with each procedure is crucial for discussion among the members of the multidisciplinary team and with the patient.7

Algorithm for the diagnosis of pulmonary fibrosis7

The pulmonary fibrosis diagnosis algorithm includes a multidisciplinary team

The participants consider all data available and propose a provisional first-choice diagnosis, assess the need for biopsy and confidence in the diagnosis, and consider possible alternative diagnoses. If a case cannot be addressed by a multidisciplinary team, it is important for the treating clinician to realize that many factors need to be considered before diagnostic decisions can be made. 
Adapted from: Wijsenbeek M, Cottin V. N Engl J Med. 2020;383:958–968.

Proactively collaborate to optimize ILD care through a multidisciplinary team approach  

HRCT is the gold standard diagnostic tool for ILDs8

How can you use HRCT to diagnose different ILDs?

Other considerations for diagnosis of ILDs:

  • On chest auscultation, fine Velcro crackles are indicative of fibrosis7
  • A thorough patient history, including environmental exposures, medication use and extrapulmonary signs, should be evaluated7


Other considerations for ILD diagnosis in CTDs:

  • In CTDs, ILD can develop either after the CTD has been diagnosed or before the rheumatological symptoms of the CTD appear
  • This makes it important to conduct physical and serologic examinations if there is any suspicion of CTD-ILD7

What if the cause of ILD is unclassifiable after assessment?

  • Some ILD cases remain unclassifiable even after thorough assessment.7 In the instance of new forthcoming information, a working diagnosis can later become a more definitive differential diagnosis


Guidelines recommend a multidisciplinary approach, involving a clinical, radiological and pathological review to achieve an early and accurate IPF diagnosis:3,9–11

HRCT scan icon.

In the absence of other known causes, HRCT, in discussion with an MDT, is necessary to confirm an IPF diagnosis3,9

Icon of three doctors, representing multidisciplinary team.

MDTs reach an IPF diagnosis more frequently and with higher confidence than individual clinicians12

In an Australian study (n=90), multidisciplinary discussion resulted in diagnosis change: 10 (37%) of 27 patients referred with a diagnosis of IPF changed to non-IPF diagnosis and 7 patients had diagnosis changed to IPF because of MDT discussion13

IPF diagnosis can stay the same or change after referral / multidisciplinary team discussion

Diagnostic algorithm for an accurate, timely diagnosis of IPF from ATS/ERS/JRS/ALAT guidelines3

Diagnosis of IPF is confirmed from either HRCT, BAL or surgical lung biopsy

*  Surgical lung biopsy is not indicated in patients at high risk for intra-, peri-, or postoperative complications (e.g. severe hypoxemia at rest and/or severe pulmonary hypertension with a diffusion capacity less than 25% after correction for hematocrit). Surgical lung biopsy may be unnecessary in some familial cases.3
Reprinted from Annals of the American Thoracic Society, 183(6), Raghu et al, An Official ATS/ERS/JRS/ALAT Statement: Idiopathic Pulmonary Fibrosis: Evidence-based Guidelines for Diagnosis and Management, p 788–824, ©2022.

For patients at risk of IPF, HRCT should be evaluated at the first suspicion of ILD involvement.9

Features consistent with a UIP pattern on HRCT include:9

  • Honeycombing

  • Reticulation

  • Traction bronchiectasis

Investigate IPF with HRCT

Example of IPF UIP pattern on HRC

ATS/ERS/JRS/ALAT guidelines recommend that IPF can be confidently diagnosed if the clinical evaluation of the patient points to IPF and the HRCT shows a definite or probable pattern of UIP (conditional biopsy recommended).3

IPF diagnosis based upon HRCT and biopsy patterns according to the ATS/ERS/JRS/ALAT Clinical Practice Guideline 20183

Guidance advises HRCT with UIP pattern can confirm IPF diagnosis

Reprinted from Annals of the American Thoracic Society, 183(6), Raghu et al, An Official ATS/ERS/JRS/ALAT Statement: Idiopathic Pulmonary Fibrosis: Evidence-based Guidelines for Diagnosis and Management, p788–824, ©2022.

If a specific diagnosis is not made or no potential cause for ILD is identified, then clinical findings and appropriate combination of HRCT and histopathological patterns are considered during multidisciplinary discussion to either ascertain or exclude the diagnosis of IPF.3

  • *
    Patients clinically suspected of having IPF are those with unexplained symptomatic or asymptomatic patterns of bilateral pulmonary fibrosis on a chest radiograph or chest computed tomography, bibasilar inspiratory crackles, and age greater than 60 years.3
  • IPF is the likely diagnosis when any of the following features are present:3
  • *
    Moderate-to-severe traction bronchiectasis/bronchiolectasis (defined as mild traction bronchiectasis/bronchiolectasis in four or more lobes including the lingual as a lobe, or moderate-to-severe traction bronchiectasis in two or more lobes) in a man over age 50 years or in a woman over age 60 years
  • *
    Extensive (>30%) reticulation on HRCT and an age >70 years
  • *
    Increased neutrophils and/or absence of lymphocytosis in BAL fluid
  • *
    Multidisciplinary discussion reaches a confident diagnosis of IPF
  • Indeterminate for IPF:3
  • *
    Without an adequate biopsy is unlikely to be IPF
  • *
    With an adequate biopsy may be reclassified to a more specific diagnosis after multidisciplinary discussion and/or additional consultation


Diagnostic tests for iNSIP involve:

Spirometer icon.

Pulmonary function tests

(showing restrictive ventilatory pattern)14

HRCT scan icon.


(ground-glass opacities; reticular opacities with lower lung zone predominance; micronodules; consolidation; minimal honeycombing)16

Bronchoscopy icon.

Surgical lung biopsy

(showing uniformity of interstitial involvement) used when HRCT suggests NSIP pattern that overlaps with the OP and DIP patterns15,17

Lung after magnifying glass icon.


(Bronchoalveolar lavage)

A multidisciplinary discussion involving pulmonologists, radiologists and pathologists is advised in cases where the clinical, radiologic and pathologic features are not definite or probable for NSIP15


Guidelines recommend that diagnosis of sarcoidosis should involve the following diagnostic tools:18

Icon of the person with magnifying glass, representing screening of the ILD symptoms.

Patient evaluation

Icon of the microscope.

Histologic and immunologic screening

Icon of the lungs.

Chest X-ray

HRCT scan icon.

CT scans

A comprehensive patient evaluation for sarcoidosis-associated interstitial lung disease should include:18

Scheme representing steps of patient evaluation while suspecting sarcoidosis associated ILD.

CT scans of patients with sarcoidosis-associated interstitial lung disease show an extent and type of fibrosis that varies from patient to patient, but is typically manifested as bronchial distortion (marked by traction bronchiectasis and airway angulation), linear scarring, and honeycombing.19

Proportions of patients with sarcoidosis-associated interstitial lung disease with radiographic features on HRCT (n=80)19

Sarcoidosis-associated interstitial lung disease patients most likely to have bronchial distortion as radiographic feature on HRCT

If the combination of clinical findings and imaging is not diagnostic, more invasive diagnostic procedures may be needed for sarcoidosis-associated interstitial lung disease, such as BAL.7


First and foremost, patient exposure history should be thoroughly examined.20

What HP exposure-related risk factors can you identify?

Patients with fibrotic HP typically have reticulation, traction bronchiectasis and volume loss, with or without honeycombing, on HRCT:20

  • Subacute HP can usually be seen on HRCT as ground-glass opacities alongside poorly-defined centrilobular nodules20
  • Expiratory HRCT imaging may be useful in diagnosing cHP7

On chest auscultation, squeaks indicative of fibrosis may be heard in patients with HP7

A surgical lung biopsy may be needed in cases with no identifiable exposure or HRCT patterns such as UIP which are less suggestive of HP21

If the combination of clinical findings and imaging is not diagnostic, more invasive diagnostic procedures may be needed for HP, such as BAL7

Once diagnosed, how can you break the news to your patients with fibrotic ILDs?

Breaking bad news is a difficult and complex communication task. In our documentary film series, Professor Walter Baile, psychiatrist and co-founder of the SPIKES model, takes us through his practical approach on how to structure difficult conversations


Chapter 1 – The challenge of breaking bad news

Professor Walter Baile introduces the challenges involved in breaking bad news and what we can learn from experiences in oncology.

Johanna: [00:00:21 – 00:00:41] Breaking bad news about a terminal illness to a patient who’s not expecting it can be emotionally challenging for everyone involved. I know this because it happened to my grandmother who suffered from pulmonary fibrosis. So, I’m in Houston now to speak to Professor Walter Baile, who’s going to tell us more about communication and how to better the conversation.     BIG CONVERSATIONS An introduction to Professor Walter Baile and The SPIKES Model Johanna: [00:39:34 – 00:39:37] So, Professor Baile, can you please introduce yourself? Professor Baile: [00:39:37 - 00:39:59] So I’m Walter Baile and I’m a psychiatrist. And I did my psychiatry training at the Johns Hopkins Hospital in Baltimore, Maryland. And for the past 30 years, I’ve worked at M.D. Anderson Cancer Centre and organized a communication skills program called iCare, which is the program for interpersonal communication and relationship enhancement. Johanna: [00:00:34 – 00:00:40] When you first started working in this field, how were bad news being communicated in oncology? Professor Baile: [00:16:03 – 00:16:51] So, the fact is, is that bad news was rarely given to cancer patients and the diagnosis was often disguised behind words such as inflammation or mass. And clinicians at that time had very few treatments for cancer and patients feared it very much because often patients died in pain. And there was very little support for them. So, not giving a diagnosis of cancer or not telling the truth to patients was considered to be something ethical that doctors would do because they would spare the patient the suffering of knowing. So, almost uniformly, patients weren’t told. Johanna: [00:16:52 – 00:17:00] But things have changed, and new treatments have become available. So, what are some of the new challenges that physicians are facing nowadays? Professor Baile: [00:01:53 – 00:02:30] So as a colleague of mine once said, you know, the question is not whether to give bad news, but how to give it. And it’s still it’s a very big challenge for doctors, because many of them now really don’t have sufficient training to give bad news and because of that, they find it very challenging and stressful to deal with the emotions that often arise when patients are given adverse information about their medical condition, even though patients today want to be informed. Johanna: [00:03:31 – 00:03:36] And you came out with a method for it. Can you briefly describe it? Professor Baile: [00:03:39 – 00:03:59] We came up with a method which we call SPIKES, which is an organized stepwise program or a method for teaching communication skills and specifically giving bad news, which consists of six separate steps, which I can talk about in a little while. Professor Baile: [00:04:34 – 00:04:59] It makes a lot of sense to doctors because they often learn to provide treatment and to diagnose disease based upon protocols and to follow guidelines for giving bad news. So that I think it’s become widely accepted because it has an inherent intuitive sense to doctors in other conditions who are giving bad news. Johanna: [00:08:31 – 00:08:33] So, Professor Baile, what does SPIKES stand for? Professor Baile: [00:08:34 – 00:09:22] So the S of SPIKES is for setting or setting up the interview, how you organise yourself before you go into the conversation. P is for perception. Finding out how much the patient already knows about the disease or the tests or any other information you want to know ‘I’ is for invitation and that is making sure the patient’s ready for the information. K is for knowledge and that is how to give the information in a way that the patient understands and allow them to share decisions. E is for emotions how to be empathic when the patient gets upset and ’S’ is for strategy and summary. How you sum up the conversation and help the patient understand what the treatment program is. Johanna: [00:08:55 – 00:09:01] What is the objective of SPIKES with not just clinicians but also with patients? Professor Baile: [00:09:05 – 09:13 and 00:09:27 – 09:52] Patients who receive bad news want to hear it in a compassionate way. So, what SPIKES does is addresses the most common emotional reactions with patients and whether it’s sadness or whether it’s fear or anxiety or crying spells and helps the clinician address that. It also prompts the doctor to prepare for giving bad news by kind of rehearsing in their own mind what they’re going to say and what they’re going to tell the patient. 

Once you have reached a diagnosis, how should you manage your patient with fibrotic ILDs?

  • ALAT, Latin American Thoracic Society; ATS, American Thoracic Society; BAL, bronchoalveolar lavage; cHP, chronic hypersensitivity pneumonitis; CT, computed tomography; CTD, connective tissue disease; CTD-ILD, connective tissue disease-associated interstitial lung disease; DIP, desquamative interstitial pneumonia; ERS, European Respiratory Society; HP, hypersensitivity pneumonitis; HRCT, high-resolution computed tomography; ILD, interstitial lung disease; iNSIP, idiopathic non-specific interstitial pneumonia; IPF, idiopathic pulmonary fibrosis; JRS, Japanese Respiratory Society; MDD, multidisciplinary discussion; MDT, multidisciplinary team; NSIP, non-specific interstitial pneumonia; OP, organizing pneumonia; uILD, unclassifiable interstitial lung disease; UIP, usual interstitial pneumonia.

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  3. Raghu G, Remy-Jardin M, Myers JL, et al; on behalf of the ATS/ERS/JRS/ALAT. Diagnosis of Idiopathic Pulmonary Fibrosis. An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline. Am J Respir Crit Care Med. 2018;198(5):e44–e68. 
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  8. Chowaniec M, Skoczyńska M, Sokolik R, Wiland P. Interstitial lung disease in systemic sclerosis: challenges in early diagnosis and management. Reumatologia. 2018;56(4):249–254.
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  10. Martinez FJ, Chisholm A, Collard HR, et al. The diagnosis of idiopathic pulmonary fibrosis: current and future approaches. Lancet Respir Med. 2017;5(1):61–71. 
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  18. American Thoracic Society. Statement on sarcoidosis. Joint Statement of the American Thoracic Society (ATS), the European Respiratory Society (ERS) and the World Association of Sarcoidosis and Other Granulomatous Disorders (WASOG) adopted by the ATS Board of Directors and by the ERS Executive Committee, February 1999. Am J Respir Med. 1999;160:736–755.
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