To refresh your memory, remember that interpreting a chest radiograph involves three basic steps:

1. Gather information. Examine the radiographs carefully and collect all the pertinent information. Remember that overlooking visible findings is the main cause of errors.

2. Analyze the findings. Once collected, the findings should be properly evaluated, and an opinion should be offered.

3. Decide on the next step to reach the diagnosis.

Step 1. Information:

In this patient the lateral view is unremarkable.
All relevant findings are seen in the PA radiograph:

1. Tubular branching opacities in the left upper lung (A, red arrows)
2. Increased lucency of left upper lung (A, circle)
3. Negative finding: the left hilum is in its normal position.

Step 2. Analysis of the findings:

1. Branching tubular opacities have a limited differential diagnosis: either they are pulmonary vessels or mucous-filled dilated bronchi.

2. Hyperlucent lung is a reliable sign of lung disease when complemented with an expiration film to demonstrate air-trapping.

3. The normal position of the left hilum is a negative finding that excludes a fibrotic process in the LUL (I.e. chronic TB), which should cause upper retraction of the hilum.

The combination of a lucent lung lesion with branching tubular opacities points towards an obstructive process of a segmental bronchus with mucous impaction (Obstruction of a lobar bronchus would cause lobar collapse instead of increased lucency).

TUBULAR BRANCHING OPACITIES + INCREASED LUNG LUCENCY = SEGMENTAL BRONCHIAL OBSTRUCTION

Step 3. Decide on the next step

Once segmental bronchial obstruction is suspected in the chest radiograph, the best procedure to confirm it is an enhanced chest CT with expiratory views. In this case it shows attenuated upper lobe vessels (B, arrows) and obvious mucous impactions (B-C, red arrows).
Axial CT with lung window confirms the increased lucency of the apical-posterior segment of the RUL (D, circle)

Inspiration/expiration axial CT views (E-F) confirm segmental air trapping on the left.

Bronchoscopy did not show any inflammatory or tumoral changes in the LUL bronchus. The orifice of the apical-posterior segment was missing.

Final diagnosis: bronchial atresia of apical-posterior segment of LUL

In my experience, bronchial atresia is the most common congenital lung malformation seen in adults. Congenital bronchial atresia results from proximal interruption of a segmental bronchus, which causes overinflation of the affected segment and secondary mucus impaction. Chest radiography shows a focal hyperlucent area with internal mucus impaction. CT depicts these findings to better advantage. Inspiration and expiration views help to confirm air-trapping. In case of doubt, bronchoscopy excludes other causes of bronchial obstruction.

Congenital bronchial atresia may present different appearances, as shown in the following case of one of our X-ray technicians.

30-year-old female, asymptomatic. PA chest radiograph (A) shows hyperlucent left lung with discrete dextroposition of the heart. Expiration film (B) shows air-trapping on the left with deviation of the mediastinum towards the right. Note a thick tubular shadow in the left lower lung (A-B, red arrows), compatible with bronchial impaction. The findings are suggestive of congenital bronchial atresia

Axial and coronal enhanced CT show increased lucency of the posterior segments of LLL with a central mucous impaction (C-D, red arrows)

Decreased vascularity of LLL and central mucous impaction (E-F, red arrows) are better demonstrated in the MIP reconstruction.

Coronal view eleven years later show that air is now present within the dilated bronchus, confirming the diagnosis (G-H, circles) .

Dr. Pepe’s teaching point:

Hyperlucent lung with mucous impaction are the hallmark of congenital bronchial atresia.

Findings: PA chest radiograph shows a rounded opacity in the left apex (A, arrow). All diagnosis are possible, as the pulmonary apex is a narrow space and it is very difficult to determine the origin of a mass. The clue lies in the nodular opacities in the neck (A, circle) which raise the possibility of superimposed hair braid.
Unenhanced coronal CT (B) does not show any mass, confirming that the finding is artifactual.

Final diagnosis: superimposed hair braid simulating pulmonary disease

The purpose of this presentation is to discuss elements in or about the soft tissues of the chest wall that may simulate lung disease. Those related to the thoracic skeleton were shown in Diploma case # 57.
This Diploma complements the non-significant findings described in webinar eight.

I have classified them into three groups, the first one related to the soft tissues of the chest wall while the other two are external to the body:

1. Nipples and skin lesions
2. Hair and/or hair implements
3. Garments

Nipple Shadows

Nipple shadows are seen in 3% to 10% of PA chest radiographs. In about 10% of these patients, the identification may raise doubts. Comparison with previous films will confirm the stability of the nodules (Fig. 1). In case of doubt, nipple markers should be placed. Routine use of nipple markers has been proposed in oncologic patients.

Unilateral enlarged nipple shadows are suspicious findings. Visual inspection should be done to confirm that the nipple is indeed enlarged (Fig. 2). Occasionally, a true lung nodule may simulate a nipple shadow, even with nipple markers. In such cases, CT will correct our error (Figs. 3-4)

Skin lesions

Skin lesions may also cause false lung nodules. Visual inspection of the chest will demonstrate them and confirm the diagnosis (Fig. 5). If there is any doubt, a marker can be used.

Occasionally, a discrepancy in density between both breasts, usually related to previous surgery, may simulate pulmonary pathology (Fig 6).

Hair

In my experience, hair is a common cause of opacities in the lung apices (Fig 7).
Strands of loose hair may project over the upper lung, simulating linear fibrotic infiltrates (Fig 8). Rubber bands at the end of braids may be confused with pulmonary nodules (Fig. 9). A long braid may fool us and consider it intrapulmonary disease (Fig 10).

In most cases, the clue to the diagnosis lies in recognizing that the abnormality extends to the neck.

Clothing artifacts

Clothing artifacts occur when the technician does not ask patients to remove garments that have logos or images on them. This usually happens with women, out of respect for modesty (Figs. 11 and 12).

Other types of body artifacts may cause dubious opacities in the chest radiograph (Figs 13 and 14)

To end the presentation, in the last two months we have been acquainted with a new artifact: the wire in the face masks (Fig 14)

Follow Dr. Pepe’s advice:

1. Unilateral nipple shadows may generate diagnostic problems.
2. If a hair artifact is suspected, look at the soft tissues of the neck.
3. Garments may create weird lung shadows.