Imaging Pearls ❯ Chest ❯ Infection
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- Neutropenia, defined as an absolute neutrophil count of less than 1500/μL, can result from chemotherapy, an organ or stem cell transplant, and hematologic malignancies such as leukemia and multiple myeloma. Neutropenia places patients at high risk for angioinvasive fungal infections such as aspergillosis, mucormycosis, and candidiasis; the risk increases with longer duration and a lower nadir of the absolute neutrophil count.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Angioinvasive aspergillosis results from the invasion of small- to medium-sized pulmonary arteries by fungal hyphae, resulting in hemorrhagic nodules or wedge-shaped pulmonary infarcts. This hemorrhage creates a rim of ground glass surrounding a solid nodule or consolidation, termed the halo sign. This sign can be seen in other conditions including hemorrhagic pulmonary metastases and vasculitis. Although the halo sign is not pathognomonic for a specific disease, when seen in a patient with neutropenia, the most likely cause is an angioinvasive fungal infection. The halo sign is frequently seen in the early stages of angioinvasive aspergillosis. When neutrophil function recovers in later stages, necrotic lung tissue begins to separate from the surroundinglung parenchyma, resulting in the air crescent sign, which refers to the lucency between the wall of the cavity and the intracavitary consolidation.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Mucormycosis, or zygomycosis, is a rare but aggressive fungal infection caused by multiple species of fungi belonging to the order Mucorales, which are ubiquitous in soil, decaying organic matter, compost, and contaminated foods. Rhizopus species are the most common cause of mucormycosis infections and are responsible for greater than 70% of cases. Mucormycosis primarily affects patients who are severely immunocompromised, such as patients with neutropenia and hematologic malignancies, those who have undergone a solid organ or bone marrow transplant, and in rare cases, those with uncontrolled diabetes. Mucormycosis is a highly aggressive infection, with a mortality rate of 48%87% of patients necessitating early recognition and treatment.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Pneumocystis jirovecii pneumonia (PJP) is a life-threatening infection most commonly seen in patients with HIV infection who have a CD4 cell count of less than 200 cells/μL, but also in patients with a congenital or acquired T-cell deficiency such as those with a hematologic malignancy or those who have undergone a stem cell or organ transplant. In patients who are not infected with HIV, the most common risk factor for PJP is prolonged steroid therapy such as that in patients with chronic lung disease; this risk is dose dependent. Although such patients usually receive prophylaxis medication, noncompliance and drug resistance may result in infection.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - The most common CT finding of PJP is extensive groundglass opacities, typically perihilar- and upper lung predominant, with a mosaic distribution. Superimposed interlobular septal thickening (ie, the crazy paving pattern) is also a characteristic feature in more advanced disease. Subpleural sparing has also been described, and consolidation can be seen in patients without HIV infection who have more aggressive disease. Although rare, PJP can manifest with cystic changes, which can be complicated by pneumothorax. Cavitation, lymphadenopathy, and pleural effusions are rare with PJP.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Tuberculosis affected an estimated 10.8 million people worldwide in 2023, causing 1.25 million deaths, and it remains one of the leading causes of death in patients with HIV infection . According to the World Health Organization, people with HIV infection are 1521 times more likely to develop active tuberculosis compared with those without HIV infection and are three times more likely to die during tuberculosis treatment even if they are undergoing antiretroviral therapy. Mycobacterium tuberculosis is transmitted through inhaled airborne droplets, and the organism subsequently infects alveolar macrophages. Because tuberculosis can affect many organ systems, radiologists play an important role in the diagnosis of tuberculosis by recognizing common patterns of involvement and their imaging manifestations.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Miliary tuberculosis, which is defined by hematogenous dissemination, is more common in immunocompromised patients, most commonly affecting the lungs, but it can affect any organ . At imaging, diffuse 13mm nodules in a random distribution characterize miliary disease. Extrapulmonary involvement is more common in immunocompromised patients; in one study, the authors found that 38% of patients had pulmonary involvement only, 30% had extrapulmonary involvement only, and 32% had both pulmonary and extrapulmonary involvement. The differential diagnosis for miliary tuberculosis includes fungal infection, which can manifest with similar imaging findings.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - KS is a low-grade mesenchymal tumor caused by human herpesvirus that involves the blood and lymphatic vessels and thus can affect many organs, resulting in a wide spectrum of imaging findings. There are four variants of KS: classic KS, which primarily affects those of eastern European or Mediterranean descent; endemic KS, which primarily affects men in East and Central Africa; organ transplantrelated or iatrogenic KS; and AIDS-related KS. KS is the most common tumor in patients with AIDS and is an AIDS-defining illness. Although the prevalence has declined with increasing use of antiretroviral therapy, patients with AIDS have a 300 times greater risk of KS compared with other immunosuppressed patients.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Myeloablative regimens before performance of a hematopoietic stem cell transplant and immunosuppressive regimens after performance of a solid organ or stem cell transplant are required for successful engraftment and to prevent rejection, respectively, but both can cause profound iatrogenic immunocompromise. All infections have the potential to be more severe in a patient with a transplant, in addition to the risk for opportunistic pathogens such as angioinvasive fungi. Indwelling catheters, stents, and any transplant organ damage or compromise further increase risks. Immunosuppression can also cause the reactivation of viruses such as Cytomegalovirus (CMV) and Epstein-Barr virus (EBV).
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Posttransplant immunosuppressive regimens vary and often target T cells, although they can result in any combination of neutropenia, T-cell depletion, and B-cell depletion. Opportunistic pathogens that commonly cause pulmonary infectionin this patient group are highlighted, in addition to posttransplant lymphoproliferative disorder (PTLD), which may mimic infection.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Posttransplant Lymphoproliferative Disorders PTLD represents a spectrum of lymphoid and/or plasma cell proliferations in a patient with chronic immunosuppression, ranging from benign lymphoid hyperplasia to poorly differentiated lymphoma. Most cases are caused by the reactivation of EBV-positive B cells in patients with immunosuppression and resultant decreased T-cell immune surveillance. Although an immunocompetent patient can reverse the B-lymphocyte proliferation caused by EBV infection due to intact cytotoxic T cells, immunosuppressed patients cannot mount this same response . PTLD can be caused by an EBV-positive donor or recipient but is more commonly caused by donor-derived EBV, and thus, the risk is increased in an EBV-positive donor to EBV-negative recipient mismatch.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021 - Patients with HIV infection or iatrogenic T-cell depletion, such as patients who have undergone a transplant who are taking calcineurin inhibitors or biologic medications such as belatacept or patients with autoimmune disorders who are taking tumor necrosis factor inhibitors, are at risk for a spectrum of opportunistic infections, but most commonly for tuberculosis, PJP, and certain malignancies such as KS. Diffuse ground-glass opacities, with or without crazy paving, suggest PJP, while consolidation and/or tree-in-bud nodules may suggest tuberculosis. Perivascular flame-shaped nodular opacities are typical of KS.
Pneumonia in Immunocompromised Patients
Silvia Arora, MD1 Stephanie M. Walker, MD1 Kristopher W. Cummings, MD2 Mark M. Hammer, MD1
RadioGraphics 2025; 45(12):e250021
- “Cystic fibrosis (CF) is the most common fatal congenital disease in the Caucasian population with a frequency of one in 2000 to 3000 live births [1]. Lung involvement in CF is characterised by chronic bacterial infection and inflammation with acute episodes of pulmonary exacerbation resulting in progressive diffuse bronchiectasis and lung function decline [1]. Although lung disease remains the main cause of morbidity and mortality in CF patients, the last decade has seen new drug therapies and lung transplantation lead to a significant improvement in survival [2]. Data from the Cystic Fibrosis Foundation 2019 Patient Registry Annual Data Report shows that the median predicted survival for CF patients in the United States improved from 38 years for those born in 2008 (95% CI, 35–39 years) to 48.4 years (95% CI, 45.9–51.5 years) for those born in 2019 [3]. This significant improvement has been largely achieved by the introduction of prevention and yearly monitoring programmes, which aim to detect disease at an early phase and closely monitor disease progression.”
State-of-the-art review of lung imaging in cystic fibrosis with recommendations for pulmonologists and radiologists from the "iMAging managEment of cySTic fibROsis" (MAESTRO) consortium.
Ciet P, Bertolo S, Ros M, et al.
Eur Respir Rev. 2022 Mar 23;31(163):210173. - “Despite many specialist centres using CR as the imaging technique of choice in infants and preschool children, CT shows higher sensitivity in detecting early abnormalities in both symptomatic and asymptomatic CF patients . Therefore, using CR in the early post-screening phase seems to be of limited value, with CT being a more efficient way of detecting early disease and monitoring disease progression . A main limitation of CT, however, for routine imaging of preschool children, is the absence of any “CT protocol harmonisation” . There is, indeed, no consensus on what dose level may be considered low and on the optimal timing of the first CT examination. State-of the art CT scanners can provide substantial dose reductions with effective radiation exposure comparable to C. Further dose reductions are expected by the introduction of the new photon-counting CT scanner, which could provide a dose reduction of up to 70% at no expense to image resolution.”
State-of-the-art review of lung imaging in cystic fibrosis with recommendations for pulmonologists and radiologists from the "iMAging managEment of cySTic fibROsis" (MAESTRO) consortium.
Ciet P, Bertolo S, Ros M, et al.
Eur Respir Rev. 2022 Mar 23;31(163):210173. - Pulmonary exacerbations are major determinants of lung function decline and mortality in the CF population with 25–50% of patients experiencing exacerbations that do not allow them to recover their prior FEV1 value following treatment. The absence of a shared definition compromises the optimal clinical management of pulmonary exacerbation, including the use of imaging for diagnosis and follow-up; this is problematic given the significant role of imaging in the clinical management of exacerbation The most frequently used imaging modality during exacerbation is CR, although its sensitivity and specificity are debated, especially in patients with severe disease. The latter group is not only at higher risk of exacerbation, but is one where it is difficult to detect new radiographic changes in a lung substrate of diffuse parenchymal abnormality.
State-of-the-art review of lung imaging in cystic fibrosis with recommendations for pulmonologists and radiologists from the "iMAging managEment of cySTic fibROsis" (MAESTRO) consortium.
Ciet P, Bertolo S, Ros M, et al.
Eur Respir Rev. 2022 Mar 23;31(163):210173. - The MAESTRO committee urges the establishment of international guidelines on CF imaging. These guidelines should provide clear indications regarding the timing and selection of the most appropriate imaging modality according to the clinical scenario, patient's age, lung disease severity and type of treatment (i.e. CFTRs). Based on this state-of-the-art review, the committee concludes that, to date, there is no concrete evidence for a role of LUS in monitoring CF lung disease. Although CR remains the most frequently used modality in CF imaging, its ability to monitor CF lung disease is controversial. Regarding CT and MRI, both techniques should be routinely and interchangeably used to monitor CF lung disease according to the patient's age, disease status and type of treatment.
State-of-the-art review of lung imaging in cystic fibrosis with recommendations for pulmonologists and radiologists from the "iMAging managEment of cySTic fibROsis" (MAESTRO) consortium.
Ciet P, Bertolo S, Ros M, et al.
Eur Respir Rev. 2022 Mar 23;31(163):210173. - Tuberculosis remains a major global health issue affecting all countries and age groups. Radiology plays a crucial role in the diagnosis and management of pulmonary tuberculosis (PTB). This review aims to improve understanding and diagnostic value of imaging in PTB. We present the old, well-established findings ranging from primary TB to the common appearances of post-primary TB, including dissemination with tree-in-bud nodularity, haematogenous dissemination with miliary nodules and lymphatic dissemination. We discuss new concepts in active PTB with special focus on imaging findings in immunocompromised individuals. We illustrate PTB appearances borrowed from other diseases in which the signs were initially described: the reversed halo sign, the galaxy sign and the cluster sign. There are several radiological signs that have been shown to correlate with positive or negative sputum smears, and radiologists should be aware of these signs as they play an important role in guiding the need for isolation and empirical anti-tuberculous therapy.
Active pulmonary tuberculosis: something old, something new, something borrowed, something blue.
Wetscherek, M.T.A., Sadler, T.J., Lee, J.Y.J. et al.
Insights Imaging 13, 3 (2022). https://doi.org/10.1186/s13244-021-01138-8 - According to the World Health Organisation (WHO), tuberculosis (TB) remains in the top 10 causes of death worldwide with approximately 10 million cases diagnosed in 2019. TB is present in all countries and age groups. Substantial efforts have been made as part of the WHO End TB strategy with a resulting 9% decrease in global incidence between 2015 and 2019. An estimated 60 million lives have been saved through improved diagnosis and treatment since 2000. However, there is concern that the COVID-19 pandemic will reverse the recent progress in reducing the TB global burden due to TB services disruption leading to delayed diagnosis, including active case finding and contact tracing, as well as treatment interruption [1].
Active pulmonary tuberculosis: something old, something new, something borrowed, something blue.
Wetscherek, M.T.A., Sadler, T.J., Lee, J.Y.J. et al.
Insights Imaging 13, 3 (2022). https://doi.org/10.1186/s13244-021-01138-8 - “Primary TB and post-primary TB are thought to be two distinct entities on the basis of clinical, pathologic and imaging findings. Primary TB manifests radiologically as four main entities: dense, homogeneous consolidation with lower and middle lobes predominance, lymphadenopathy, miliary disease and pleural effusion. Classical CT findings in post-primary PTB include centrilobular nodules, “tree-in-bud” sign, consolidation, ground-glass opacities, cavitation, bronchial wall thickening, miliary nodules, an isolated pulmonary nodule, parenchymal bands and interlobular septal thickening”
Active pulmonary tuberculosis: something old, something new, something borrowed, something blue.
Wetscherek, M.T.A., Sadler, T.J., Lee, J.Y.J. et al.
Insights Imaging 13, 3 (2022). https://doi.org/10.1186/s13244-021-01138-8 - “Patchy, poorly defined areas of heterogeneous consolidation are among the earliest manifestations of active PTB. The distribution is primarily in the apical and posterior segments of the upper lobes and less frequent in the apical segments of the lower lobes, with commonly more than one pulmonary segment involved [5]. Tuberculous consolidation can be challenging to distinguish from bacterial pneumonia in absence of associated findings such as lymphadenopathy or cavitation and the lack of response to conventional antibiotics. In their evolution, these regions liquefy and form cavities by draining through the tracheobronchial tree. Cavitation affects about 50% of patients. The cavities are usually multiple and typically have thick, irregular walls, which become smooth and thin with successful treatment. Cavities may demonstrate air-fluid levels which can also indicate superinfection.”
Active pulmonary tuberculosis: something old, something new, something borrowed, something blue.
Wetscherek, M.T.A., Sadler, T.J., Lee, J.Y.J. et al.
Insights Imaging 13, 3 (2022). https://doi.org/10.1186/s13244-021-01138-8 - Characteristic findings of central airway TB include irregular circumferential wall thickening with luminal narrowing. Isolated tracheal disease is rare with most patients presenting with distal trachea, carina and proximal main stem bronchi involvement . The coexistence of tracheobronchial disease and lymphadenopathy is high in patients with active pulmonary TB. In the pathophysiology of tracheobronchial TB, peribronchial lymphatic spread seems more common than endobronchial spread from infected sputum. Bronchial stenosis occurs in 10–40% of patients with active tuberculosis and can lead to segmental or lobar atelectasis, lobar hyperinflation, mucoid impaction, and post-obstructive pneumonia .
Active pulmonary tuberculosis: something old, something new, something borrowed, something blue.
Wetscherek, M.T.A., Sadler, T.J., Lee, J.Y.J. et al.
Insights Imaging 13, 3 (2022). https://doi.org/10.1186/s13244-021-01138-8 - Miliary TB describes haematogenous dissemination, resulting in randomly distributed nodules which have uniform size between 1 and 4 mm. They may have a slight lower lobe predominance, often associated with intra- and interlobular septal thickening , and may coalesce to form focal or diffuse consolidation . Chest radiography is usually unremarkable at the onset of symptoms and the nodules only become discernible after 4 weeks [8]. CT can reveal miliary disease before it becomes radiographically apparent [7]. Miliary TB may be seen in association with typical parenchymal changes or may be the only pulmonary abnormality Miliary disease has been reported to be associated with both childhood and immunocompromised adult infections manifesting within 6 months of initial exposure [5]. This pattern’s diffuse random distribution distinguishes it from the patchy centrilobular distribution of tree-in-bud. Other organs with high blood flow, such as the liver, spleen, bone marrow, adrenals and kidneys, are also frequently affected .
Active pulmonary tuberculosis: something old, something new, something borrowed, something blue.
Wetscherek, M.T.A., Sadler, T.J., Lee, J.Y.J. et al.
Insights Imaging 13, 3 (2022). https://doi.org/10.1186/s13244-021-01138-8
- Sarcoidosis: Facts
- Multisystem, autoimmune disorder with formation of noncaseous granulomas. Pulmonary involvement is seen in 90% of patients and accounts for a majority of the morbidity and mortality of the disease
- Common presenting symptoms include cough, dyspnea, and fatigue although many patients with sarcoidosis are asymptomatic.
- More than half of patients experience minimal consequences from the disease but around one fifth of patients can develop pulmonary fibrosis. - Tuberculosis: Facts
- Initial infection with Mycobacterium tuberculosis is referred to as primary tuberculosis and can appear radiographically as mediastinal and hilar lymphadenopathy, consolidation, pleural effusion, or nodules.
- Following resolution of the primary infection, tuberculosis can appear as upper lung consolidations and cavitations.
- Both primary and post-primary disease can affect the bronchial wall and manifests as bronchial wall involvement and bronchial stenosis due to lymphadenitis. - Nontuberculous Mycobacterial Infection: Facts
- Typically occurs in older women (Lady Windermere Syndrome) and presents with chronic cough
- CT imaging usually shows peripheral bronchiectasis, bronchial wall thickening, tree-in-bud nodules, and larger random nodules that may cavitate
- Usually spares the upper lungs; classic location is in the right middle lobe and lingula - Allergic Bronchopulmonary Aspergillosis: Facts
- Typically occurs in patients with long standing asthma or cystic fibrosis
- Presents with wheezing and pneumonia-like symptoms of productive cough and fever
- Imaging classically shows the "finger-in-glove" sign of dilated tubular branching opacities which demonstrates mucus plugging
- Attenuation of the mucus plug will exceed that of skeletal muscle on noncontrast CT - Tracheobronchial Amyloidosis: Facts
- Amyloidosis is a multisystem disorder of abnormal protein deposition. Tracheobronchial manifestations include airway wall thickening and intramural nodules that can be complicated by airway obstruction
- Airway involvement can be circumferential including the posterior membrane unlike cartilaginous disorders (ie. relapsing polychondritis and tracheobronchopathia osteochondroplastica)
- Disease of the upper airway presents with typical upper airway symptoms while disease of the lower airways presents with recurrent pneumonia and lobar collapse - Risk factors for primary spontaneous pneumothorax
- Smoking
- Tall thin body habitus in an otherwise healthy person
- Pregnancy
- Marfan syndrome
- Familial pneumothorax - Diseases associated with secondary spontaneous pneumothorax
- COPD
- Asthma
- HIV with pneumocystis pneumonia
- Necrotizing pneumonia
- Tuberculosis
- Sarcoidosis
- Cystic fibrosis
- Bronchogenic carcinoma
- Idiopathic pulmonary fibrosis - Causes of tension pneumothorax
- Penetrating or blunt trauma
- Barotrauma due to positive pressure ventilation
- Percutaneous tracheostomy
- Conversion of spontaneous pneumothorax to tension
- Open pneumothorax when occlusive dressing work as one way valve
- “The hallmark of esophageal disorders with regard to recurrent lung infection is spillage of gastroesophageal contents into the lungs due to alterations in esophageal structure or physiology. In achalasia, dysfunction of the esophageal myenteric plexus results in aperistalsis of the lower esophagus and defective relaxation of the lower esophageal sphincter. A Zenker diverticulum can be a reservoir for ingested contents. Systemic sclerosis causes atrophy of the esophageal smooth muscles with subsequent esophageal dysmotility, dilatation, and gastroesophageal reflux. Tracheoesophageal fistulas are serious complications that may develop from various underlying causes, including congenital disorders, iatrogenic factors, radiation, trauma, and neoplasm.”
Anatomic and Pathologic Causes of Recurrent Pulmonary Infections.
Harowicz MR, Al Khalifah A, Cohen KA, DeMaio A, Illei PB, Fishman EK, Lin CT.
Radiographics. 2023 Jun;43(6):e220106. doi: 10.1148/rg.220106. PMID: 37261962. - “Among congenital disorders, proximal interruption of the pulmonary artery and pulmonary sequestration are both characterized by an abnormal pulmonary arterial supply. Diseases with variant pulmonary blood flow can result in poor delivery of inflammatory cells, which weakens the immune response. Congenital causes of bronchiectasis result in airway collapse and impaired airway clearance; for example, bronchial atresia (focal bronchial interruption associated with distal mucus impaction) and Williams-Campbell syndrome (deficient cartilage in the fourth- to sixth-order bronchi).”
Anatomic and Pathologic Causes of Recurrent Pulmonary Infections.
Harowicz MR, Al Khalifah A, Cohen KA, DeMaio A, Illei PB, Fishman EK, Lin CT.
Radiographics. 2023 Jun;43(6):e220106. doi: 10.1148/rg.220106. PMID: 37261962. - “The lungs’ immunologic defense against infections is impaired by immunodeficiency syndromes, including common variable immunodeficiency (deficiencies in B cells), Good syndrome (associated with thymomas and B- or T-cell abnormalities), and secondary immunodeficiencies. Immunocompetentpatients with asthma or cystic fibrosis are susceptible to allergic bronchopulmonary aspergillosis, caused by Aspergillus organisms in the bronchial mucosa causing excessive immune system activation, repeated bronchospasm, bronchial wall edema, and resultant bronchiectasis.”
Anatomic and Pathologic Causes of Recurrent Pulmonary Infections.
Harowicz MR, Al Khalifah A, Cohen KA, DeMaio A, Illei PB, Fishman EK, Lin CT.
Radiographics. 2023 Jun;43(6):e220106. doi: 10.1148/rg.220106. PMID: 37261962. - “Tracheobronchial variants include single or multiple tracheal outpouchings (diverticuli); accessory airways, particularly cardiac bronchi; and tracheobronchomalacia. Recurrent airway injury and chronic inflammation are typical for several conditions owing to ineffective airway clearance. Thick mucus in cystic fibrosis alters bacterial killing, and repeated infections lead to bronchiectasis. Nontuberculous mycobacterial infection can have a chronic indolent or progressive course and tends to occur in the setting of structural lung disease or bronchiectasis. Right middle lobe atelectasis due to extrinsic airway compression or nonobstructive causes results in chronic inflammation and/or infection, predisposing to bronchiectasis.”
Anatomic and Pathologic Causes of Recurrent Pulmonary Infections.
Harowicz MR, Al Khalifah A, Cohen KA, DeMaio A, Illei PB, Fishman EK, Lin CT.
Radiographics. 2023 Jun;43(6):e220106. doi: 10.1148/rg.220106. PMID: 37261962. - TEACHING POINTS
* The hallmark of esophageal disorders with regard to recurrent lung infection is spillage of gastroesophageal contents into the lungs due to alterations in esophageal structure or physiology.
* Diseases with variant pulmonary blood flow can result in poor delivery of inflammatory cells, which weakens the immune response.
* Immune cell deficiency, impaired or excessive immune system reaction, and variations in mucociliary clearance blunt the immune response and predispose to lung infections.
Anatomic and Pathologic Causes of Recurrent Pulmonary Infections.
Harowicz MR, Al Khalifah A, Cohen KA, DeMaio A, Illei PB, Fishman EK, Lin CT.
Radiographics. 2023 Jun;43(6):e220106. doi: 10.1148/rg.220106. PMID: 37261962.