Fluorography

Place of fluorography in diagnostic radiology

Fluorography is a basic tool for mass prevention; however, the arsenal of diagnostic radiology includes a number of other, more detailed techniques. If fluorographic screening reveals suspicious changes, the patient is prescribed additional examinations:

• Targeted chest X-ray — performed in two projections (anteroposterior/posteroanterior and right lateral). Unlike fluorography, it is carried out on standard film, which better delineates indistinct focal opacities and the bronchovascular pattern. This is the gold standard when pneumonia, pleurisy, or neoplasms are suspected.
• Fluoroscopy of the lungs — allows real-time assessment of the respiratory organs. The physician can determine the transparency of the lung fields, identify cavities, fluid or air in the pleural cavity, as well as dense pleural adhesions and scars.
• Computed tomography (CT) — used as a confirmatory method when the radiographic picture is unclear. CT is necessary to assess the extent of the pathological process and properly plan treatment.
• Tomography — a method of layer-by-layer examination that is effective for detecting small infiltrates, cavities, and tumors.
• Bronchography — a highly specialized examination of the bronchi. A radiopaque contrast agent (iodolipol) that attenuates X-rays is injected into the respiratory tract under local anesthesia. The images provide a clear visualization of the bronchial tree, making it possible to diagnose bronchiectasis, abscesses, and bronchial stenosis caused by a tumor.

Diagnosis of Tuberculosis

Chest fluorography is a mandatory stage of examination in clinical suspected tuberculosis. To definitively rule out the disease, diagnostic imaging is supplemented with immunodiagnostics. The patient undergoes an intradermal test with a tuberculosis allergen (using a recombinant allergen at standard dilution). An alternative or supplement is laboratory blood testing for the level of interferon-gamma against Mycobacterium tuberculosis complex antigens.

Indications for standard radiography

Unlike screening fluorography, radiography is prescribed according to strict clinical indications. It is mandatory for all patients with symptoms of community-acquired pneumonia and signs of bronchitis. Special attention is paid to patients with exacerbation of chronic bronchitis presenting with the following "red flags":

1. Pronounced tachycardia (heart rate greater than 90 beats per minute).
2. Shortness of breath (respiratory rate over 22 breaths per minute).
3. Hyperthermia (body temperature above 38 °C).
4. Specific physical examination findings (dullness to percussion, characteristic auscultatory pattern).

A standard X-ray image is also necessary when sarcoidosis or lung cancer is suspected.

Age-related features on images

A diagnostic radiologist always interprets images taking into account the patient's age.

Features in children:

• In respiratory distress syndrome (RDS) in newborns, the picture forms within the first 6 hours. There is a diffuse decrease in transparency (especially in the lower lobes and apices), a decrease in lung tissue aeration, and an "air bronchogram" sign. Although the RDS pattern is nonspecific, radiography is strictly mandatory to rule out surgical pathologies. Resolution of signs takes 1 to 4 weeks.
• In bronchopulmonary dysplasia (BPD) in full-term infants, the changes are identical to the classic form in premature infants. In the first months, a "mottled" pattern is visible: areas of interstitial edema alternate with areas of hyperlucency, and fibrous strands are visible.
• In adolescents, the bone framework of the chest is still developing. Growth plates of the vertebrae and ribs can produce additional linear shadows on the image, which should not be mistaken for pathology. Adolescents aged 15 and older are indicated for fluorography or radiography once every 6 months (upon registration, e.g., for HIV, and strictly in the absence of active tuberculosis).

Features in the elderly: With age, the pulmonary pattern becomes accentuated due to vascular sclerosis and interstitial fibrosis. Emphysematous changes develop: transparency of the lung fields increases, intercostal spaces widen, and the ribs assume a horizontal orientation (an early sign of emphysema is a decrease in excursion of the lung margin).

Calcifications in the lungs and lymph nodes are frequently detected—traces of past infections. Costal cartilages and the aorta undergo compaction and calcification, and the aortic arch itself unfolds and elongates. The decrease in tissue elasticity leads to a drop in vital capacity (VC), a sharp decrease in diffusing capacity, bronchial obstruction (decreased Tiffeneau index), and an increase in residual volume (a sign of "air trapping").

Class and exam questions

What else to study on this topic

• Immunodiagnostics of tuberculosis (interferon assays and recombinant allergen test)
• Computed tomography of the chest: treatment planning and extent assessment
• Contrast-enhanced bronchography (iodolipol) and diagnosis of bronchiectasis
• Spirometric parameters (Tiffeneau index, VC) in age-related decrease in lung elasticity
• Respiratory distress syndrome and bronchopulmonary dysplasia in newborns

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.