|Year : 2018 | Volume
| Issue : 1 | Page : 50-55
Sonographic features of idiopathic pulmonary fibrosis
Osama F Mansour1, Mohammed A Agha MD 1, Ahmed A Al-Asdody1, Naglaa S Mehana2, Rehab M Habib3
1 Chest Department, Faculty of Medicine, Menoufia University, Shebin El-Kom, Egypt
2 Chest Department, EL Zaton Specialized Hospital, Cairo, Egypt
3 Department of Radiology, Faculty of Medicine, Menoufia University, Shebin El-Kom, Egypt
|Date of Submission||21-Dec-2017|
|Date of Acceptance||10-Jan-2018|
|Date of Web Publication||21-Mar-2018|
Mohammed A Agha
Assistant Professor of Chest Diseases and Tuberculosis, Chest Department, Menoufia University, Shebin El-Kom, 32511
Source of Support: None, Conflict of Interest: None
Background Idiopathic pulmonary fibrosis (IPF) is a specific form of idiopathic interstitial pneumonia (IIP) that occurs primarily in the elderly and is confined to the lungs. With the use of transthoracic ultrasound (TUS), diffuse parenchymal lung disease should be considered if multiple comet-tail artifacts distributed over the whole surface of the lung together with a thickened and irregular, fragmented pleural line are visible.
Objective The aim of this study was to evaluate lung ultrasound usefulness in the diagnosis of IPF.
Patients and methods This study was carried out on 40 patients diagnosed as having IPF. All cases were subjected to a full assessment of history, clinical examination, laboratory investigations, arterial blood gases, pulmonary function test, plain chest radiography, high-resolution computed tomography, and TUS.
Results Our results showed that B-lines in combination with thickened and irregular pleura are the TUS features of IPF. There was a statistically significant correlation among B-lines distance (mm), pleural line thickness (mm), pleural line irregularity, abolished lung sliding found by TUS, and severity of the disease.
Conclusion TUS is a useful tool in the diagnosis and assessment of the severity of IPF and can be used as a complementary method beside high-resolution computed tomography. The distance between two adjacent lines in combination with thickened and irregular pleura is a good feature in the follow-up of disease progression.
Keywords: high-resolution computed tomography, idiopathic pulmonary fibrosis, transthoracic ultrasound
|How to cite this article:|
Mansour OF, Agha MA, Al-Asdody AA, Mehana NS, Habib RM. Sonographic features of idiopathic pulmonary fibrosis. Egypt J Chest Dis Tuberc 2018;67:50-5
|How to cite this URL:|
Mansour OF, Agha MA, Al-Asdody AA, Mehana NS, Habib RM. Sonographic features of idiopathic pulmonary fibrosis. Egypt J Chest Dis Tuberc [serial online] 2018 [cited 2020 Apr 3];67:50-5. Available from: http://www.ejcdt.eg.net/text.asp?2018/67/1/50/228135
| Introduction|| |
Idiopathic pulmonary fibrosis (IPF) is one of the commonest types of idiopathic interstitial pneumonia, which is the main type of diffuse interstitial lung diseases (DILD). To diagnose IPF in the absence of surgical lung biopsy, two conditions are required: first is the exclusion of other causes of diffuse parenchymal lung diseases (DPLD), and the second, which is the most important, is the characteristic pattern on high-resolution computed tomography (HRCT) which is the usual interstitial pneumonia (UIP) . By monitoring increasing symptoms, deterioration of pulmonary function test (PFT) results, and increased fibrosis on HRCT, the severity of the disease can be assessed. Chest radiography does not have a big role in the diagnosis of IPF. The presence of bilateral, basal, and subpleuritic reticular pattern is the main feature of UIP . Traction bronchiectasis and honeycombing are common features with basal and subpleural distribution. Usually in a less extensive way than the reticular pattern, ground glass opacities (GGO) may be present on HRCT in patients with IPF. Other pleural abnormalities such as pleural plaques, effusion, or calcifications make an alternative etiology for UIP pattern more common than IPF . Moreover, in the presence of air trapping, nodules, or consolidations, other alternative diagnosis should be considered . One of the main advantages of transthoracic ultrasound (TUS) is the absence of electromagnetic radiation . The importance of TUS in the diagnosis of different respiratory disorders has been established in different studies ,,. Beside its diagnostic value, TUS has a big role in different lung interventional methods such as biopsies and thoracentesis . Bilateral B-lines with pleural thickening and pleural irregularity are the main TUS features in DPLD . B-lines occur owing to the thickening occurring in the subpleural interlobular septa. However, B-lines may occur in patients with other pulmonary disorders as chronic obstructive pulmonary disease, bronchiolitis obliterans with organizing pneumonia, pulmonary alveolar proteinosis, and pulmonary embolism ,.
Aim of the work
The aim of this work was to assess the usefulness of lung ultrasound (US) in the diagnosis of IPF.
| Patients and methods|| |
A prospective cohort study was conducted on already diagnosed 40 patients with IPF (on the basis of exclusion of other known causes of DPLDs and the presence of UIP pattern on HRCT in the form of basilar, subpleural reticular opacities, and honeycombing with or without traction bronchiectasis)  who were admitted to the Chest Department, Menoufia University Hospitals, from September 2015 to September 2017. This study was approved by the ethical committee of the Menoufia University.
All patients were subjected to the following:
- History and clinical examination: it included symptoms and signs, comorbidities, occupations, special habits of medical importance, and if there was relevant drug history or relevant family history.
- Laboratory investigations: it included arterial blood gases, liver functions tests, kidney function tests, and complete blood count.
- Chest radiography: it was done in posteroanterior view and lateral if needed.
- PFTs: it was done to confirm the restrictive pattern of the disease and assess its severity for every patient.
Chest high-resolution computed tomography assessment
HRCT examination was performed for all patients, and the extent of each abnormality was estimated for each lobe.
- Transthoracic ultrasonography: All the patients underwent TUS examination using an US scanner (digital US imaging system model equipped with a 3.5-MHz convex probe and 7.5–10 MHz linear probe; Philips ultrasound Affiniti 50G, Philips, Germany). All patients had their examination in a sitting or supine position with arms raised above their head. Lung ultrasonography was performed in a series of scan lines along the chest wall with the transducer oriented either perpendicular or transverse to the chest wall.
- Transthoracic lung US interpretation: Assessment of the pleura was done regarding pleural thickness and pleural surface (smooth, irregular, or interrupted). Pleural thickenings are defined as focal or diffuse echogenic lesions arising from the visceral or parietal pleura that are greater than 3 mm in width with or without an irregular pleural surface . Presence or absence of lung sliding (the ‘to-and-fro’ dynamic movement of the lung during respiration) was estimated; lung sliding was demonstrated as fleeting dots arising from the pleural line which moves with lung movement during breathing . Recognition of B-lines, which were previously called comet-tail artifacts, appearing on the screen as laser-like vertical echogenic artifacts arising from the pleural line, spreading up without fading to the edge of the screen, and moving synchronous with lung sliding, generated from the thickened interlobular septa at the lung wall interface, was assessed ,. By parasternal, anterior, and posterior axillary lines, each hemithorax was divided into three regions, which were subdivided into upper and lower regions. Finally, there were six regions for each hemithorax. The presence of at least three B-lines in one region made it a positive region, and the presence of at least two positive regions bilaterally made it a positive examination result. Measurement in millimeters of the distance between two adjacent B-lines was done .
Data were coded and analyzed using SPSS 17. Data were expressed as median and percentiles for quantitative nonparametric measures in addition to both number and percentage for categorized data .
| Results|| |
This study (prospective cohort study) was done on 40 patients diagnosed as having IPF. Their ages ranged from 47 to 65 years old. They were 24 male and 16 female patients, with 21 smokers. The most common presenting symptom was dyspnea followed by dry cough, and the most common comorbidity was gastroesophageal reflux (GERD) ([Table 1]). Regarding the TUS features found in the studied group, B-lines were found in all (100%) patients. Regarding pleural line features, 85% of patients with IPF had irregular pleural lines, with 77.5% of the 40 patients having pleural thickening. Overall, 82.5% of the studied patients had normal lung sliding, and in 92.5% of the patients, subpleural nodules were absent ([Table 2]). There was a statistically negative significant correlation between the distances between each of two adjacent B-lines and with both forced vital capacity and partial arterial oxygen pressure in the studied patients ([Table 3]). Regarding the correlation between TUS features and the degree of severity of IPF (measured by degree of restriction in PFTs), increased distance (in mm) between B-lines, pleural thickening and irregularity, and absence of normal lung sliding were associated with the severity of the disease ([Table 4]). The distance between two adjacent B-lines correlated with the degree of extension of reticular pattern in HRCT ([Figure 1],[Figure 2],[Figure 3]).
|Table 3 Correlations between distance a mong B-lines and both forced vital capacity and PaO2|
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|Table 4 Correlations of ultrasonographic pleural features and severity of pulmonary function test|
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|Figure 1 Correlation between reticular patterns on high-resolution computed tomography and B-line distance in patients with idiopathic pulmonary fibrosis.|
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|Figure 2 A 55-year-old male patient presented with progressive dyspnea. high-resolution computed tomography shows bilateral basal reticular pattern, and transthoracic ultrasound shows the presence of B-lines with irregular pleural lines.|
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|Figure 3 A 61-year-old male patient with bilateral basal mild reticular pattern, confirmed with transthoracic ultrasound features (pleural thickening and B-lines).|
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| Discussion|| |
To diagnose IPF in the absence of surgical lung biopsy, two conditions are required: first the exclusion of other causes of DPLD, and the second one, which is the most important, is the characteristic pattern on HRCT, which is the UIP. The importance of TUS in the diagnosis of different respiratory disorders has been established in different studies ,,. The present study was designed to evaluate ultrasonographic features in patients with IPF; moreover, the results of the US examination were compared with PFTs, and with the arterial oxygen tension. This study was done on 40 patients diagnosed as having IPF. Their ages ranged from 47 to 65 years. In the present work, regarding the sex, there was a male predominance (24 male and 16 females), with 21 being smokers. The most common presenting symptom was dyspnea followed by dry cough, and the most common comorbidity was GERD ([Table 1]). The previous findings are in agreement with many studies that concluded that IPF should be considered in all adult patients with unexplained progressive dyspnea and commonly presents with cough, bibasilar inspiratory crackles, and finger clubbing ,,. Moreover, many studies illustrated the increasing incidence of the disease with patients in old ages, especially in the sixth and seventh decades of lift ,,,. Nadrous et al.  and Iwai et al.  concluded that the occurrence of IPF in patients younger than 50 years is rare, and in such patients, the incidence of pulmonary fibrosis secondary to connective tissue disorders is the commonest differential diagnosis. Moreover, the studies showing the increased incidence of IPF in men more than women and the increased incidence in smokers are present . Hubbard et al.  and Steele et al.  concluded that smoking is strongly associated with IPF, particularly for individuals with a smoking history of more than 20 pack-years. Regarding GERD, several studies concluded that GERD is a risk factor for IPF. GERD is common in patients with IPF ,,. GERD is frequent in the normal population as well as in patients with other advanced lung diseases such as lung fibrosis associated with scleroderma . In the present study, all the 40 (100%) cases had bilateral diffuse B-lines, three (7.5%) cases had subpleural lesions, 34 (85%) cases had irregular pleural line, and 31 (77.5%) cases had pleural thickening. Moreover, in seven (17.5%) cases, lung sliding was absent ([Table 2]). [Table 3] shows that increased distance between two adjacent B-lines was associated with severity of restriction of lung functions and severity of the degree of hypoxemia. In addition, [Table 4] shows that features of IPF detected with TUS, such as distance between B-lines, irregularity of pleural lines, thickened pleural lines, and absence of lung sliding, were associated with the severity of the degree of restrictive pulmonary functions. In the present work, the degree of reticulation in HRCT was associated with the severity of the conditions ([Figure 1]). Many studies were done to assess the value of TUS in patients with interstitial lung diseases including IPF, and all studies illustrated the importance of B-lines in the diagnosis DPLD. Targhetta et al.  studied TUS in 12 patients with pulmonary sarcoidosis and found that all patients had both an irregular pleural surface and B-lines. Moreover, Gargani et al.  found that 51% of the patients with systemic sclerosis (SSc) had B-lines as a hallmark of interstitial pulmonary fibrosis. Suzan et al.  found that the most predominant artifact type among patients with ILD was B-lines (73.8%). Hasan and Makhlouf  found that all their 61 patients with DILD had diffuse bilateral B-lines. Comparable results were obtained by Reissig and Kroegel  who found that 84.9% of their patients with DPLDs had thickened pleural surface and 98.1% had irregular pleura. Moreover, Sperandeo et al.  studied TUS features of pulmonary fibrosis in patients with different disease severity and found that 100% of the patients had irregular and fragmented pleural lines, with thickened pleura in 92.8% and reduction or absence of normal lung sliding sign in 28% of cases. In a study done by Reissig and Kroegel , at least six B-lines per scan were found with an irregular pleural line. It also was similar to the results obtained by Moazedi-Fuerst et al.  who studied TUS findings in 25 patients with SSc and 25 healthy individuals as control group and found that 44% of patients with SSc had B lines with pleural thickening. Buda et al.  correlated the US findings of IPF with the HRCT findings, and found that features of IPF were the presence of B-lines, irregular with thickened pleural lines. Moazedi-Fuerst et al.  studied the role of TUS in 55 patients with different connective tissue disorders and 40 healthy control group. B-lines, subpleural nodes, and irregularities of the pleura were assessed with TUS. These features assessed with TUS were significantly more frequent in IPF group. In the present study, the distance between two adjacent B lines negatively correlated with forced vital capacity and PaO2 ([Table 3]) and positively correlated with the reticular pattern in HRCT ([Figure 1]). The previous findings are in accordance with the results of Hasan and Makhlouf  and Assayag et al.  who stated that the distance between two adjacent B-lines is positively correlatedwith the severity and extension of the fibrosis on using the Warrick scoring system on HRCT, and this also agreed with Suzan et al.  who studied the correlation between distance between two adjacent B-lines and found positive correlations with reticular pattern and negative correlation with GGO. The same findings were supported by Bouhemad et al.  as they concluded that multiple B-lines are associated with reticular pattern, whereas B-lines 3 mm or less apart are associated with GGO. Moreover, Gargani et al. , Hasan and Makhlouf , and Suzan et al.  proved the correlation between distance between B-line and PFTs and found that there was deterioration of the disease with increased distance between B-lines. Regarding the data obtained from [Table 4], there was a significant difference in median value of pleural thickness (mm) between all groups involved. In addition, there was a significant difference in percentage of patients with irregular pleura and absent or reduced lung sliding between mild, moderate, and severe groups. Moreover, all severe cases showed irregular pleural line over whole lung (100%), thickened pleura, and nearly absent lung sliding. In this study, different TUS features for IPF were found, including thickened pleura, irregular pleural lines, absent lung sliding, and the presence of B-lines ([Table 2]). This is in agreement with Sperandeo et al.  who studied 84 consecutive patients. They found that features of IPF in TUS were fragmented, irregular thickening pleural line, subpleural cysts, and reduction or absence of the sliding sign.
| Conclusion|| |
Chest US can be used as a complementary method for the diagnosis of IPF beside HRCT. TUS is a good method for follow-up patients with IPF as chest US is an effective noninvasive modality that requires neither ionizing radiation nor a contrast medium. Bilateral B-lines in combination with thickened and irregular pleura are a good TUS features for assessment of the severity of IPF. Increased B-lines distance can be used as a marker of pulmonary function deterioration and for the presence of increased reticular pattern on HRCT.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Raghu G, Collard H, Egan J, Martinez F, Behr J, Brown K et al.
An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management. Am J Respir Crit Care Med 2011; 183:788–824.
Launay D, Remy-Jardin M, Michon-Pasturel U, Masora L, Hachulla E, Lambert M et al.
High resolution computed tomography in fibro sing alveolitis associated with systemic sclerosis. J Rheumatol 2006; 33:1789–1801.
Peros-Golubicic T, Sharma Om P. Clinical atlas of interstitial lung disease. London: Springer 2006. p. 10.
Strickland B, Strickland N. The value of high definition, narrow section computed tomography in fibro sing alveolitis. Clin Radiol 1988; 39:589–594.
Koegelenberg CFN, Bolliger CT, Diacon AH. Pleural ultrasound. In: Light RW, Lee YC, editors. Textbook of pleural disease. 2nd ed. London: Hodder and Stoughton 2008. pp. 275–283.
Gargani L. Lung ultrasound: a new tool for the cardiologist. Cardiovasc Ultrasound 2011; 9:6.
Mayo PH. Ultrasound evaluation of the lung. In: Levitov A, Mayo PH, Slonim AD, editors. Critical care ultrasonography. New York, NY: McGraw-Hill 2009. pp. 251–258.
Soldati G, Copetti R, Sher S. Sonographic interstitial syndrome: the sound of lung water. J Ultrasound Med 2009; 28:163–174.
Soldati G. Sonographic findings in pulmonary diseases. Radiol Med 2006; 111:507–515.
Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest 2008; 1341:117–125.
Koenig SJ, Narasimhan M, Mayo PH. Thoracic ultrasonography for the pulmonary specialist. Chest 2011; 140:1332–1341.
Anantham D, Ernst A. Ultrasonography. In: Mason RJ, Broaddus VC, Murray JF, Nadel JA, editors. Murray and Nadel’s textbook of respiratory medicine. 5th ed. Philadelphia: Saunders-Elsevier 2010. pp. 445–460.
Lichtenstein DA. Should lung ultrasonography be more widely used in the assessment of acute respiratory disease? Expert Rev Respir Med 2010; 4:533–538.
Reissig A, Kroegel C. Transthoracic ultrasound of lung and pleura in the diagnosis of pulmonary embolism: a novel non-invasive bedside approach. Respiration 2003; 70:441–452.
Tsai TH, Jemg J-S, Yang P-C. Clinical applications of transthoracic ultrasound in chest medicine. J Med Ultrasound 2008; 16:7–25.
Levesque R. SPSS programming and data management. a guide for SPSS and SAS users. 4th ed. Chicago, IL: SPSS Inc; 2007.
Douglas WW, Ryu JH, Schroeder DR. Idiopathic pulmonary fibrosis: Impact of oxygen and colchicine, prednisone, or no therapy on survival. Am J Respir Crit Care Med 2000; 161:1172–1178.
King TE Jr, Tooze JA, Schwarz MI, Brown KR, Chrniack RM. Predicting survival in idiopathic pulmonary fibrosis: scoring system and survival model. Am J Respir Crit Care Med 2001; 164:1171–1181.
Gribbin J, Hubbard RB, Le Jeune I, Smith CJ, West J, Tata LJ. Incidence and mortality of idiopathic pulmonary fibrosis and sarcoidosis in the UK. Thorax 2006; 61:980–985.
Scott J, Johnston I, Britton J. What causes cryptogenic fibrosing alveolitis? A case-control study of environmental exposure to dust. Brit Med J 1990; 301:1015–1017.
Mannino DM, Etzel RA, Parrish RG. Pulmonary fibrosis deaths in the United States, 1979-1991: an analysis of multiple-cause mortality data. Am J Respir Crit Care Med 1996; 153:1548–1552.
Raghu G, Freudenberger TD, Yang S, Curtis JR, Spada S, Hayes J et al.
High prevalence of abnormal acid gastro-oesophageal reflux in idiopathic pulmonary fibrosis. Eur Respir J 2006; 27:136–142.
Raghu G, Weycker D, Edelsberg J. Incidence and prevalence of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 2006; 174:810–816.
Nadrous HF, Myers JL, Decker PA, Ryu JH. Idiopathic pulmonary fibrosis in patients younger than 50 years. Mayo Clin Proc 2005; 80:37–40.
Iwai K, Mori T, Yamada N, Yamaguchi M, Hosoda Y. Idiopathic pulmonary fibrosis: epidemiologic approaches to occupational exposure. Am J Respir Crit Care Med 1994; 150:670–675.
Coultas DB, Zumwalt RE, Black WC, Sobonya RE. The epidemiology of interstitial lung diseases. Am J Respir Crit Care Med 1994; 150:967–972.
Hubbard R, Lewis S, Richards K, Johnston I, Britton J. Occupational exposure to metal or wood dust and etiology of cryptogenic fibrosing alveolitis. Lancet 1996; 347:284–289.
Steele MP, Speer MC, Loyd JE, Brown KK, Herron A, Slifer SH et al.
Clinical and pathologic features of familial interstitial pneumonia. Am J Respir Crit Care Med 2005; 172:1146–1152.
Tobin RW, Pope CE II, Pellegrini CA, Emond MJ, Sillery J, Raghu G. Increased prevalence of gastroesophageal reflux in patients with idiopathic pulmonary fibrosis. Am J Respir Crit Care Med 1998; 158:1804–1808.
Patti MG, Tedesco P, Golden J. Idiopathic pulmonary fibrosis: how often is it really idiopathic? J Gastrointest Surg 2005; 9:1053–1056.
D’Ovidio F, Singer LG, Hadjiliadis D, Pierre A, Waddell TK, de Perrot M. Prevalence gastroesophageal reflux in end-stage lung disease candidates for lung transplant. Ann Thorac Surg 2005; 80:1254–1260.
Targhetta R, Chavagneux R, Balmes P, Lemerre C, Mauboussin JM, Bourgeois JM, Pourcelot L. Sonographic lung surface evaluation in pulmonary sarcoidosis: preliminary results. J Ultrasound Med 1994; 13:381–388.
Gargani L, Doveri M, D’Errico L, Frassi F, Bazzichi ML, Delle Sedie A et al.
Ultrasound lung comets in systemic sclerosis: a chest sonography hallmark of pulmonary interstitial fibrosis. Rheumatology (Oxford) 2009; 48:1382–1387.
Suzan S, Gamal M, Azza F, Ahmed H. Assessment of transthoracic sonography in patients with interstitial lung diseases. Egypt J Bronchol 2016; 10:105–112.
Hasan A, Makhlouf H. Transthoracic chest ultrasound signs useful in the assessment of interstitial lung diseases. Ann Thorac Med 2014; 9:99–103.
Sperandeo M, Varriale A, Sperandeo G, Filabozzi P, Piattelli ML, Carnevale V. Transthoracic ultrasound in the evaluation of pulmonary fibrosis: our experience. Ultrasound Med Biol 2009; 35:723–729.
Moazedi-Fuerst F, Zechner P, Tripolt J, Kielhauser SM, Brickmann K, Scheidl S. Pulmonary echography in systemic sclerosis. Clin Rheumatol 2012; 31:1621–1625.
Buda N, Piskunowicz M, Porzezinska M, Kosiak W, Zdrojewski Z. Lung ultrasonography in the evaluation of interstitial lung disease in systemic connective tissue diseases: criteria and severity of pulmonary fibrosis-analysis of 52 patients. Ultraschall Med 2016; 37:379–385.
Assayag D, Kaduri S, Hudson M, Hirsch A, Baron M. High resolution computed tomography scoring systems for evaluating interstitial lung disease in systemic sclerosis patients. Rheumatology 2012; S1:003.
Bouhemad B, Zhang M, Lu Q, Rouby J. Clinical review: bedside lung ultrasound in critical care practice. Crit Care 2007; 11:205–223.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]