(Radiographics. 2001;21:121-131.)
© RSNA, 2001
Spectrum of Clinical and Radiographic Findings in Pediatric Mycoplasma Pneumonia1
Susan D. John, MD,
Janaki Ramanathan, MD and
Leonard E. Swischuk, MD
1 From the Department of Radiology, University of Texas–Houston Medical School, 6431 Fannin–MSB2.100, Houston, TX 77030 (S.D.J.); and the Department of Radiology, University of Texas Medical Branch, Galveston (J.R., L.E.S.). Recipient of a Certificate of Merit for a scientific exhibit at the 1999 RSNA scientific assembly. Received March 27, 2000; revision requested April 25 and received June 9; accepted June 9. Address correspondence to S.D.J. (e-mail: susan.d.john@uth.tmc.edu).
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Abstract
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Clinical symptoms in mycoplasma infection are nonspecific. Pulmonary involvement may be widespread or focal and segmental and is accompanied by signs including rales, rhonchi, and decreased breath sounds. Although manifestations of mycoplasma infection are usually confined to the respiratory tract, a wide variety of extrarespiratory manifestations can also occur, including more severe associated diseases such as myocarditis, acute disseminated encephalomyelitis, and cerebral arteriovenous occlusion. The radiographic findings in mycoplasma pneumonia are also nonspecific and in some cases closely resemble those seen in children with viral infections of the lower respiratory tract. Focal reticulonodular opacification confined to a single lobe is a radiographic pattern that seems to be more closely associated with mycoplasma infection than with other types of pediatric respiratory illnesses, and the diagnosis of mycoplasma pneumonia should be considered whenever focal or bilateral reticulonodular opacification is seen. Hazy or ground-glass consolidations frequently occur, but dense homogeneous consolidations like those seen with bacterial pneumonias are uncommon. Atelectasis or transient pseudoconsolidations due to confluent interstitial shadows are often seen. Radiographic findings alone are not sufficient for the definitive diagnosis of mycoplasma pneumonia, but in combination with clinical findings they can significantly improve the accuracy of diagnosis in this disease.
Index Terms: Lung, infection, 60.2061 • Pneumonia, 60.2061 • Radiography, in infants and children, 60.11
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LEARNING OBJECTIVES
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After reading this article and taking the test, the reader will be able to:
- Develop a framework for approaching the diagnosis of mycoplasma infection in children.
- Recognize the focal reticulonodular pattern seen in some patients, as well as other common findings.
- Identify the important clinical features of myoplasma infec-tion and correlate them with radiographic findings.
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Introduction
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Mycoplasma pneumoniae, a small, cell wall–deficient bacterium, is an important and treatable cause of community-acquired, atypical pneumonia in children (1–3). The M pneumoniae organism is pleomorphic and demonstrates variable clinical and radiographic findings. At microscopic analysis, these organisms assume variable forms that can resemble fungal filaments. The lack of a cell wall makes them insensitive to the usual antibiotics that are used to treat other common pneumonias; therefore, differentiation from bacterial pulmonary infections is vital to successful treatment. Mycoplasma pneumonia can mimic viral respiratory tract infections both clinically and radiographically; unlike viruses, however, mycoplasma infection is treatable. Appropriate antibiotic therapy for mycoplasma infections (usually with erythromycin, azithromycin, or tetracycline) can help prevent the spread of the infection to contacts and limit the course of the disease in the patient. Prompt therapy may also help avert extrarespiratory manifestations of mycoplasma pneumonia, which can occasionally be severe.
A wide variety of radiographic findings have been attributed to mycoplasma respiratory infections over the years (4–10). Several authors have described the tendency of mycoplasma infection to produce focal interstitial changes in the lungs (4,6,7). We, too, made this observation, and so began to catalog cases of children with clinical or radiographic findings suggestive of mycoplasma pneumonia.
In this article, we discuss, illustrate, and correlate the clinical and radiographic findings in children and adolescents with serologic evidence of M pneumoniae pulmonary infection.
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Clinical Experience
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We prospectively identified 120 children and adolescents over a 10-year period who were suspected of having mycoplasma pneumonia, based on clinical findings or on the presence of a reticular or nodular pattern confined to one pulmonary lobe at chest radiography. Clinical findings that raised suspicion for mycoplasma infection were variable, but the most common reasons for suspicion were persistent dry cough, lack of fever or a low-grade fever less than 38.5°C, prominent headache or myalgias, illness lasting more than 1 week, and lack of response to antibiotics. At least one posteroanterior and one lateral chest radiograph were obtained in each patient. Two adolescents were also evaluated with computed tomography (CT). Radiographs were independently evaluated by two pediatric radiologists (S.D.J., L.E.S.) for the presence of the following findings: (a) a focal reticular, nodular, or reticulonodular pattern; (b) focal consolidation (subcategorized as dense or hazy); (c) a diffuse interstitial pattern; (d) parahilar peribronchial opacification; (e) hilar lymphadenopathy; (f) pleural effusion; and (g) atelectasis or air trapping. The findings were later compared, and discrepancies were resolved by consensus. Referring physicians were encouraged to verify the diagnosis of mycoplasma pneumonia with serologic titers whenever possible. A positive diagnosis was made on the basis of a single elevated titer or a fourfold increase in titer. Of the 57 patients who were tested for serologic evidence of infection with M pneumoniae, 42 (74%) had seropositive findings and were included in the study. The study population included children and adolescents of all ages except for infants less than 1 year old (age range, 1–16 years; mean, 8.2 years). Although the majority of patients with mycoplasma pneumonia in our study were more than 5 years of age, some children were less than 5 years old, including two children between 12 and 24 months of age. Some were hospital patients, whereas others were outpatients.
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Results
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Radiographic findings included focal pulmonary areas of increased opacity in 35 of 42 patients (83%), diffuse or bilateral perihilar areas of increased opacity in five (12%), and normal findings in two (5%). Focal pulmonary areas of increased opacity occurred on the right side in 17 patients (40%) and on the left side in 13 (31%) and were seen bilaterally in five (12%). Focal lobar involvement was much more common in the lower lobes (28 of 35 patients [80%]) than in the upper or middle lobes (seven of 35 [20%]). Pleural effusions were seen in seven patients (17%), and all effusions occurred on the left side except for bilateral effusions in one patient. Hilar lymphadenopathy occurred in three patients (7%); in all three cases, the lymph nodes were unilateral and right-sided.
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Clinical Features of Mycoplasma Infection
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Humans are the only known reservoir for M pneumoniae. This tiny organism measures less than 350 µ in length and is not visible at light microscopy. Mycoplasma infection is spread by direct contact or by aerosol. The incubation period is usually 1–2 weeks. Mycoplasma infection is uncommon in the 1st year of life but is an important cause of community-acquired respiratory infections in school-age children and in even younger children who attend child care centers.
The symptoms of M pneumoniae infections are nonspecific, and the onset of illness is usually gradual. The illness may begin in the upper respiratory tract as a mild pharyngitis, often accompanied by low-grade fever, headache, and myalgias; rhinorrhea and nasal congestion are uncommon. Within a few days, symptoms of tracheobronchitis develop, and the predominant symptom is usually a nagging, dry cough (2). Wheezing is not a common symptom in children with no history of asthma, but mycoplasma infection can precipitate an acute asthma attack. Indeed, mycoplasma infection is an important cause of asthma exacerbation in children (11). Fever and sputum production can occur, but they are not as severe as in pneumococcal and other bacterial pneumonias (1). Typically, the interval between initial symptoms and fully developed pneumonitis is 6–10 days. Postinfectious bronchitis may continue for weeks or months.
Clinical signs of mycoplasma infection of the lungs include rales, rhonchi, and decreased breath sounds (Table 1), but signs of major consolidation are rare. Pulmonary involvement may be widespread or focal and segmental. White blood cell count is usually within the normal range. When the white blood cell count is elevated, a superimposed bacterial infection is often the cause. Sputum that exhibits polymorphonuclear and mononuclear cells but few bacteria should raise suspicion for mycoplasma infection.
Although illness caused by M pneumoniae is usually confined to the respiratory tract, a wide variety of extrarespiratory manifestations can occur (Table 2). The cause of these manifestations is still unknown, but autoimmune responses to the infection are suspected. Some of the more severe associated diseases include myocarditis, acute disseminated encephalomyelitis, and cerebral arteriovenous occlusion (12–14). In most cases, nonrespiratory manifestations are preceded by respiratory symptoms, but treatment of the pulmonary disease seems to have little effect on subsequent neurologic disease. The interval between respiratory symptoms and neurologic manifestations is approximately 10 days (15).
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Histopathologic Features of Mycoplasma Infection
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The histopathologic features of mycoplasma infection are limited primarily to ciliated respiratory epithelium from the trachea to the respiratory bronchioles (16). Airways are surrounded by mononuclear cell infiltrates (Fig 1). Peribronchial infiltrate can extend into the interstitium along blood vessels and lymphatic vessels (17). Both polymorphonuclear and mononuclear cells may be found in the lumen of the airways. This pattern is similar to that seen with viral lower respiratory tract infections, which explains why many of the radiographic features of these infections are also similar. Hematogenous spread of mycoplasma infection is rare.
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Figure 1. Mycoplasma pneumonia. Photomicrograph (hematoxylin-eosin stain) shows a bronchiole surrounded by mononuclear cells. Note the polymorphonuclear cells and desquamated epithelium in the lumen.
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Radiographic Features of Mycoplasma Infection
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The radiographic patterns observed in patients with M pneumoniae infections of the lower respiratory tract are variable (Table 3). No clear pattern of lobar involvement was identified in our study, but the lower lobes were more commonly affected than the upper lobes. Previous studies have also noted a lower lobe predominance (4,7). Involvement of one or two lobes was more common in our study than diffuse pulmonary disease. Previous studies have shown diffuse or multilobar involvement to be more common, but we were more likely to identify children with unilobar disease because of our interest in this pattern. Severe pulmonary complications of mycoplasma pneumonia have been reported, including Swyer-James syndrome, pulmonary fibrosis, bronchiolitis obliterans, and adult respiratory distress syndrome. However, none of these complications was encountered in our series of patients.
The most common radiographic pattern encountered in our study was a reticulonodular pattern confined to one lobe (Figs 2, 3). This pattern correlates with the histopathologic findings of peribronchitis. In some cases, the nodules were less well defined and resembled small, focal patchy areas of increased opacity (Fig 2c), but the pattern of opacification was distinct from the homogeneous consolidations seen with typical bacterial pneumonias. In several patients, the focal reticulonodular pattern was the initial radiographic finding but later progressed to other patterns. In other cases, reticulonodular changes were noted adjacent to more homogeneous lobar areas of increased opacity. Other authors have described similar reticulonodular interstitial infiltrates but have not observed a propensity for lobar involvement (4,6,7). The common occurrence of the lobar reticulonodular pattern in our study may be partially due to selection bias. The nodular appearance seen on radiographs obtained in our patients with mycoplasma pneumonia most likely correlates with the centilobular or acinar shadows detected by Tanaka et al (9) in a recent CT study of community-acquired pneumonias. Although pathophysiologically mycoplasma respiratory infections are most commonly diffuse and bronchial or peribronchial in nature, the radiographic manifestations often reflect the presence of lobar interstitial disease.
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Figure 2a. Focal reticulonodular patterns in four different patients. (a) Posteroanterior radiograph demonstrates a localized nodular pattern in the right upper lobe. (b) Posteroanterior radiograph shows a reticulonodular pattern confined to the left lower lobe. (c) Posteroanterior radiograph shows a reticular pattern in the right lower lobe accompanied by small, patchy areas of increased opacity (arrows). (d) Radiograph demonstrates a reticular pattern with mild, hazy opacification in the right lower lobe.
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Figure 2b. Focal reticulonodular patterns in four different patients. (a) Posteroanterior radiograph demonstrates a localized nodular pattern in the right upper lobe. (b) Posteroanterior radiograph shows a reticulonodular pattern confined to the left lower lobe. (c) Posteroanterior radiograph shows a reticular pattern in the right lower lobe accompanied by small, patchy areas of increased opacity (arrows). (d) Radiograph demonstrates a reticular pattern with mild, hazy opacification in the right lower lobe.
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Figure 2c. Focal reticulonodular patterns in four different patients. (a) Posteroanterior radiograph demonstrates a localized nodular pattern in the right upper lobe. (b) Posteroanterior radiograph shows a reticulonodular pattern confined to the left lower lobe. (c) Posteroanterior radiograph shows a reticular pattern in the right lower lobe accompanied by small, patchy areas of increased opacity (arrows). (d) Radiograph demonstrates a reticular pattern with mild, hazy opacification in the right lower lobe.
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Figure 2d. Focal reticulonodular patterns in four different patients. (a) Posteroanterior radiograph demonstrates a localized nodular pattern in the right upper lobe. (b) Posteroanterior radiograph shows a reticulonodular pattern confined to the left lower lobe. (c) Posteroanterior radiograph shows a reticular pattern in the right lower lobe accompanied by small, patchy areas of increased opacity (arrows). (d) Radiograph demonstrates a reticular pattern with mild, hazy opacification in the right lower lobe.
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Figure 3a. Focal reticulonodular pattern. Frontal (a) and lateral (b) radiographs obtained in an adolescent girl show opacification in the right lower lobe, which appears hazy because of overlying breast tissue. The reticular nature of this infiltrate is seen in b (arrows).
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Figure 3b. Focal reticulonodular pattern. Frontal (a) and lateral (b) radiographs obtained in an adolescent girl show opacification in the right lower lobe, which appears hazy because of overlying breast tissue. The reticular nature of this infiltrate is seen in b (arrows).
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Diffuse interstitial and bilateral parahilar peribronchial patterns are common in mycoplasma respiratory infections (Fig 4). The radiographic findings are indistinguishable from those seen in children with various viral infections of the lower respiratory tract or other pathogens that cause primarily bronchial and peribronchial disease such as pertussis and chlamydia. Atelectasis is a common associated finding in affected patients (Figs 4d, 5), providing a clue to the bronchial nature of the disease.
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Figure 4a. Diffuse interstitial and parahilar peribronchial patterns in four different patients. (a) Posteroanterior radiograph shows a mild, diffuse nodular pattern throughout both lungs with bronchial wall thickening. (b) Posteroanterior radiograph demonstrates more severe interstitial disease bilaterally, with both patchy nodular areas and central alveolar areas of increased opacity on the right side. (c) Posteroanterior radiograph obtained in a child shows a pattern resembling that of a viral infection, with bilateral parahilar peribronchial opacification and multiple areas of subsegmental atelectasis (arrows). (d) Radiograph demonstrates a slightly nodular pattern in the lung bases with atelectasis bilaterally.
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Figure 4b. Diffuse interstitial and parahilar peribronchial patterns in four different patients. (a) Posteroanterior radiograph shows a mild, diffuse nodular pattern throughout both lungs with bronchial wall thickening. (b) Posteroanterior radiograph demonstrates more severe interstitial disease bilaterally, with both patchy nodular areas and central alveolar areas of increased opacity on the right side. (c) Posteroanterior radiograph obtained in a child shows a pattern resembling that of a viral infection, with bilateral parahilar peribronchial opacification and multiple areas of subsegmental atelectasis (arrows). (d) Radiograph demonstrates a slightly nodular pattern in the lung bases with atelectasis bilaterally.
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Figure 4c. Diffuse interstitial and parahilar peribronchial patterns in four different patients. (a) Posteroanterior radiograph shows a mild, diffuse nodular pattern throughout both lungs with bronchial wall thickening. (b) Posteroanterior radiograph demonstrates more severe interstitial disease bilaterally, with both patchy nodular areas and central alveolar areas of increased opacity on the right side. (c) Posteroanterior radiograph obtained in a child shows a pattern resembling that of a viral infection, with bilateral parahilar peribronchial opacification and multiple areas of subsegmental atelectasis (arrows). (d) Radiograph demonstrates a slightly nodular pattern in the lung bases with atelectasis bilaterally.
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Figure 4d. Diffuse interstitial and parahilar peribronchial patterns in four different patients. (a) Posteroanterior radiograph shows a mild, diffuse nodular pattern throughout both lungs with bronchial wall thickening. (b) Posteroanterior radiograph demonstrates more severe interstitial disease bilaterally, with both patchy nodular areas and central alveolar areas of increased opacity on the right side. (c) Posteroanterior radiograph obtained in a child shows a pattern resembling that of a viral infection, with bilateral parahilar peribronchial opacification and multiple areas of subsegmental atelectasis (arrows). (d) Radiograph demonstrates a slightly nodular pattern in the lung bases with atelectasis bilaterally.
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Figure 5a. Diffuse interstitial and parahilar peribronchial pattern. (a) Initial posteroanterior radiograph obtained in a child shows a streaky, hazy area in the right lower lobe. (b) Posteroanterior radiograph obtained 2 days later shows resolution of the atelectasis, leaving a focal reticular pattern.
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Figure 5b. Diffuse interstitial and parahilar peribronchial pattern. (a) Initial posteroanterior radiograph obtained in a child shows a streaky, hazy area in the right lower lobe. (b) Posteroanterior radiograph obtained 2 days later shows resolution of the atelectasis, leaving a focal reticular pattern.
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Hilar lymphadenopathy is uncommon in mycoplasma pneumonia, but unilateral hilar lymph node enlargement was seen in a few patients in our study (Fig 6). The radiographic findings in these patients may be indistinguishable from those seen in children with primary tuberculosis. In a recent high-resolution CT study of patients with M pneumoniae infections, lymphadenopathy was seen in only one of 14 patients (7%) (18). In other studies, it has been reported in up to 22% of patients (4,8).
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Figure 6a. Unilateral (right-sided) hilar lymphadenopathy. (a) Posteroanterior radiograph obtained in a child demonstrates a reticulonodular area of increased opacity in the right upper lobe (arrows) accompanied by a nodular pattern in the right hilum due to lymphadenopathy. (b) Posteroanterior radiograph obtained in a different child demonstrates right hilar prominence due to lymphadenopathy (arrows). The adjacent area of increased opacity in the lung was predominantly due to atelectasis.
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Figure 6b. Unilateral (right-sided) hilar lymphadenopathy. (a) Posteroanterior radiograph obtained in a child demonstrates a reticulonodular area of increased opacity in the right upper lobe (arrows) accompanied by a nodular pattern in the right hilum due to lymphadenopathy. (b) Posteroanterior radiograph obtained in a different child demonstrates right hilar prominence due to lymphadenopathy (arrows). The adjacent area of increased opacity in the lung was predominantly due to atelectasis.
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Segmental and lobar consolidations have been reported with variable frequency (from rare up to 57% of cases) in previous series of patients with mycoplasma pneumonia (4–8,10). The differences in the reported prevalence of consolidations in mycoplasma pneumonia may be due to considerable variability in the appearance of pulmonary areas of increased opacity that are viewed as consolidations by different observers. In our study, consolidations were seen in 33% of patients (Figs 7–10). However, the majority (11 of 13) of these consolidations consisted of homogeneous areas of hazy or ground-glass opacification (Figs 8–10) or patchy inhomogeneous areas of increased opacity rather than the homogeneous dense opacification characteristic of bacterial pneumonias. In some patients, the consolidation was preceded by focal reticulonodular opacification (Fig 11) or accompanied by a reticulonodular pattern in another portion of the lungs. In other patients, a slight reticulonodular appearance was noted at the margins of more homogeneous hazy opacification. Occasionally, a transient consolidation was seen on the initial radiographs but cleared rapidly, leaving behind a focal reticulonodular pattern (Fig 5). In such cases, these pseudoconsolidations were probably due to atelectasis or transient edema complicating the focal bronchial and interstitial process. Patients in our study with consolidations were only slightly more likely to have more severe clinical signs and symptoms than were patients with diffuse peribronchial or localized reticulonodular changes. A well-known feature of mycoplasma pneumonia is the discrepancy between the severity of the radiographic changes and the relatively mild clinical findings in some patients.
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Figure 7a. Consolidation and "pseudoconsolidation." (7a) Radiograph shows bilateral areas of hazy consolidation in the lower lobes with air bronchograms. (7b) CT scan demonstrates bilateral lower lobe consolidation that appears more solid than that seen at radiography.
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Figure 7b. Consolidation and "pseudoconsolidation." (7a) Radiograph shows bilateral areas of hazy consolidation in the lower lobes with air bronchograms. (7b) CT scan demonstrates bilateral lower lobe consolidation that appears more solid than that seen at radiography.
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Figure 8. Posteroanterior radiograph obtained in a child demonstrates a round, hazy area of increased opacity (arrows) that could represent an early consolidation or pseudoconsolidation.
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Figure 10a. Consolidation and pseudoconsolidation in an 11-year-old patient. (a) Initial posteroanterior radiograph demonstrates a mild reticular pattern on the right side (arrows). (b) Posteroanterior radiograph obtained 4 days later reveals that a focal, hazy area of increased opacity has developed. (c) CT scan shows areas of mild ground-glass attenuation and acinar attenuation confined to the right lower lobe.
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Figure 10b. Consolidation and pseudoconsolidation in an 11-year-old patient. (a) Initial posteroanterior radiograph demonstrates a mild reticular pattern on the right side (arrows). (b) Posteroanterior radiograph obtained 4 days later reveals that a focal, hazy area of increased opacity has developed. (c) CT scan shows areas of mild ground-glass attenuation and acinar attenuation confined to the right lower lobe.
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Figure 10c. Consolidation and pseudoconsolidation in an 11-year-old patient. (a) Initial posteroanterior radiograph demonstrates a mild reticular pattern on the right side (arrows). (b) Posteroanterior radiograph obtained 4 days later reveals that a focal, hazy area of increased opacity has developed. (c) CT scan shows areas of mild ground-glass attenuation and acinar attenuation confined to the right lower lobe.
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Figure 11a. Progression of mycoplasma infection in a child. (a) Initial posteroanterior radiograph shows only a small reticulonodular area in the right lower lobe (arrows). (b) On a posteroanterior radiograph obtained 2 weeks later, the reticulonodular area has become more prominent (arrows). (c) Posteroanterior radiograph obtained 1 week after b reveals atelectasis in the right middle and lower lobes and a hazy pseudoconsolidation in the left upper lobe.
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Figure 11b. Progression of mycoplasma infection in a child. (a) Initial posteroanterior radiograph shows only a small reticulonodular area in the right lower lobe (arrows). (b) On a posteroanterior radiograph obtained 2 weeks later, the reticulonodular area has become more prominent (arrows). (c) Posteroanterior radiograph obtained 1 week after b reveals atelectasis in the right middle and lower lobes and a hazy pseudoconsolidation in the left upper lobe.
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Figure 11c. Progression of mycoplasma infection in a child. (a) Initial posteroanterior radiograph shows only a small reticulonodular area in the right lower lobe (arrows). (b) On a posteroanterior radiograph obtained 2 weeks later, the reticulonodular area has become more prominent (arrows). (c) Posteroanterior radiograph obtained 1 week after b reveals atelectasis in the right middle and lower lobes and a hazy pseudoconsolidation in the left upper lobe.
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Pleural effusions were uncommon in our study and were uniformly small (Fig 12). Previous studies have reported a prevalence of 5%–20% for pleural effusions (4–6,8,18). These effusions are usually transient and of no clinical significance; occasionally, however, the pleural fluid may persist after resolution of the pulmonary parenchymal findings.
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Figure 12a. Pleural effusions. (a, b) Posteroanterior (a) and lateral (b) radiographs obtained in a child demonstrate a reticular and slightly nodular focal area of increased opacity in the left lower lobe, with an associated small pleural effusion (arrow). Note the slight bowing of the oblique fissure (arrowheads in b), a finding that indicates volume loss. (c) Posteroanterior radiograph obtained in a different child demonstrates subsegmental atelectasis and a vague reticular pattern in the left lower lobe with a small pleural effusion (arrow).
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Figure 12b. Pleural effusions. (a, b) Posteroanterior (a) and lateral (b) radiographs obtained in a child demonstrate a reticular and slightly nodular focal area of increased opacity in the left lower lobe, with an associated small pleural effusion (arrow). Note the slight bowing of the oblique fissure (arrowheads in b), a finding that indicates volume loss. (c) Posteroanterior radiograph obtained in a different child demonstrates subsegmental atelectasis and a vague reticular pattern in the left lower lobe with a small pleural effusion (arrow).
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Figure 12c. Pleural effusions. (a, b) Posteroanterior (a) and lateral (b) radiographs obtained in a child demonstrate a reticular and slightly nodular focal area of increased opacity in the left lower lobe, with an associated small pleural effusion (arrow). Note the slight bowing of the oblique fissure (arrowheads in b), a finding that indicates volume loss. (c) Posteroanterior radiograph obtained in a different child demonstrates subsegmental atelectasis and a vague reticular pattern in the left lower lobe with a small pleural effusion (arrow).
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Conclusions
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The radiographic findings in mycoplasma pneumonia are variable, and in some cases they closely resemble those seen in children with viral infections of the lower respiratory tract. Although none of the findings are specific, focal reticulonodular opacification confined to a single lobe seems to be more closely associated with mycoplasma infection than with other types of respiratory illnesses in children. The diagnosis of mycoplasma pneumonia should be considered whenever focal or bilateral reticulonodular opacification is seen. Hazy or ground-glass consolidations occur with M pneumoniae infections, but dense homogeneous consolidations like those seen with bacterial pneumonias are uncommon. Transient pseudoconsolidations due to confluent interstitial shadows or atelectasis are common. Definitive diagnosis of mycoplasma pneumonia cannot be made on the basis of imaging features alone, but a combination of clinical and radiographic findings can significantly improve the accuracy of diagnosis in this disease.
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Abstract
LEARNING OBJECTIVES
