For all bronchiolitis is characterized by: a similar clinical picture with progressive shortness of breath, a weak response (for a exceptions) to therapy with corticosteroids, poor prognosis.

are acute and chronic process in advanced lesion
emit diffused form - panbronhiolit. Constrictive bronchiolitis share
caused by inhalation of harmful substances, medications, postinfectious,
caused by rheumatoid arthritis, and other processes and, finally, of unknown origin
- idiopathic. From the standpoint of histomorphological changes in the walls of the bronchial tubes secrete
tsellyulyarny, follicular, dust, constrictive,
constrictive with intraluminal polyposis, diffuse panbronhiolit.

Occurs concentric constriction of terminal bronchioles, partial or
complete their obliteration by scar connective tissue grows into
submucosal layer and / or in the adventitia. There bronchiolar, peribronhiolyarny
chronic inflammatory infiltrate, mucus plugs in the lumen, stasis
secretion formed bronhioloektazy. In the pathological process than
terminal and respiratory bronchioles can be involved large bronchi, where
often found cylindrical bronchiectasis.

For all bronchiolitis is characterized by: a similar clinical picture with
progressive shortness of breath, weak response (with some exceptions) to therapy
glucocorticosteroid, a poor prognosis. Constrictive bronchiolitis
form leads to a pronounced pathomorphological changes of terminal divisions
respiratory tract [2].

Opportunities radiological methods

imagistic - X-rays and X-ray computed tomography (CT)
- basic in vivo assessment of lung microstascture [3-7].

dvuhproektsionnaya Conventional radiography and tomography longitudinal
register advanced cases bronchiolitis, revealing diffuse,
diffuse patchy increased lung pattern, emphysematous inflated areas
lung, peribronchial fibrosis, major bronchi, and seal roots, a small
mobility of the diaphragm (Fig. 1). Changes on radiographs are nonspecific and
observed not only with bronchiolitis, but also in many other pathological states
.

Fig. 1. Survey X-ray light

In the absence of pathological changes in distal parts of the respiratory tract and
lung parenchyma at the level of segments are not displayed on the computer tomograms
high resolution (HRCT). However, the inflammatory process in
bronchioles causes thickening of the wall, the accumulation and stasis of secretions in
lumen, the development of alveolar hypoventilation, or, conversely, its swelling due
valvular disorders of ventilation. With the development of fibrosis violated
hemodynamics due to hypoxia, spasms, zapustevaniya arterioles, venules. Complex
above processes depending on the location, distribution, phase
flow leads to image abnormal bronchioles and alveolar tissue
on HRCT.

In connection with low resistance terminal respiratory tract in the early stages of lesion
bronchioles may be asymptomatic, not accompanied by changes
function tests and HRCT allows you to diagnose the disease at
preclinical stage of its development.

CT features of various morphological variants of bronchiolitis

CT scan, depending on the histomorphologic variants
obstasctive bronchiolitis reveals various changes macrostascture
respiratory tract. Tsellyulyarnaya, follicular form, bronchiolitis
smokers, professional forms of bronchiolitis have identical map
with HRCT. Inflammation involves all layers of the wall bronchioles and
clearance (follicular bronchiolitis with lymphoid hyperplasia occurs
elements) formed peribronhiolyarny components. In a series of computer
tomograms determined tsentrilobulyarno located, dense, small (1-2 mm)
foci located inside or wedges linear stascture is the same thickness as the
extending from the main line at an acute angle with additional "branches". At
some branches on the main line visualization capabilities tsentrilobulyarnyh
foci described above the stascture. This symptom is designated by us as "a branch of willow"
(Fig. 2). These symptoms are caused by CT imaging the bronchial tubes, sealed
by inflammation and accumulation of mucus in the lumen. If you hit them in parallel
CT slice are displayed in the form of willow branches, with the perpendicular arrangement
tsentrilobulyarnogo foci of round shape - respectively
anatomical course vozduhoprovodyaschih ways. Sharp contours, homogeneous
internal stascture, soft tissue density (40-60 units). Indicate far
came by inflammation, irreversible fibrotic changes. Increased
focal and linear stasctures ofmorethan 5-6 mm, the emergence of fuzzy sets
contours show the distribution of the inflammatory process in the environmental
alveolar tissue.

This is an important prognostic sign of complications of obliterative bronchiolitis
- obliterative bronchiolitis with organizing pneumonia (OBOP).
respiratory bronchioles (bronchiolitis smoker) is different from previous types of bronchiolitis the appearance of lesions
tsentrilobulyarnoy emphysema, areas of "ground glass".
This is attributable to the valve mechanism violations ventilation cloves
by narrowing the lumen of the bronchioles with subsequent transition to hypoventilation
slices. When scanning on the inspiratory and expiratory ventilation zone lesions
virtually unchanged (as in the emphysematous changes, and in patients with lesions type
"matte"), which indicates their obstasctive etiology (Fig. 3).

Figure 2. HRCT. Small focal subplevralnye stascture, a symptom of "willow branches".

Fig. 3. CT. Peribronchial fibrosis, bronchiectasis, a symptom of "frosted glass
" tsentrilobulyarnaya emphysema.

Tsellyulyarny bronchiolitis, if not promptly recognized and was not subjected to
treatment can go into the development of bronchiolitis obliterans with intraluminal
polyposis or constrictive bronchiolitis form. When you first arise
endobronchial polyps of connective tissue that either floated in
lumen, or tightly fixed to the wall of the bronchioles. CT determined
tsentrilobulyarno located foci measuring 2-3 mm or more, reflecting
granulation tissue polyps and peribronchial inflammation. Often in the process
dynamic observation of patients with follicular bronchiolitis is defined
increase the size of the bronchioles detected, the appearance of fuzziness of their contours, which indicate progress
derivations of the process, the development of polyps.

In some cases, bronchiolitis can begin with the development of polyposis, whereas
prevails visualization tsentrilobulyarnyh foci as a manifestation of polyposis, and
symptom "willow branches" poorly expressed (Fig. 4).

Fig. 4. HRCT (CU). Tsentrilobulyarnye foci with follicular bronchiolitis
.

constrictive form of bronchiolitis - a result of all kinds of diseases. Develops
irreversible fibrosis with concentric narrowing of the bronchioles. Fibrosis is distributed along the bronchioles
violates the collateral ventilation, causing obstasction. The narrowing of the lumen
bronchioles leads to hypoxia, vasoconstriction, rise
original air bags (valve mechanism), and then atelectasis
slices. CT detected "mottled" pattern of lung tissue due to
alternating sections of high and low density, irregularly alternating
with each other. This is due to impaired blood flow in the constriction
bronchioles, oligemiey in the area and the redistribution of perfusion to areas of undisturbed
ventilation. CT, these zones have increased transparency.
patchiness changes in the density of light is better seen when scanning a given
same region easier to inhale and exhale, as the ventilation
pathologically changed part of the lung does not change in different phases of respiration. With a significant
distribution changes caused by obstasctive bronchiolitis, the difference in density
different parts of pulmonary tissue to inhale and exhale, leveled,
remain the same regardless of the phase of respiration.

One constrictive bronchiolitis options - a syndrome Swyee-James,
occur in children after suffering a viral bronchiolitis. Defeat is
unilateral, develop bronchiectasis with thin wall sections
tsentrilobulyarnoy emphysema, decreased lung tissue transparency.

in Japan first described the diffuse form of bronchiolitis, called diffuse
panbronhiolitom . The disease is prevalent in South-East Asia
(Taiwan, Korea, China, Japan). There were reports of detection of the disease
in England, France, Germany, USA and Norway. The connection of the disease with
paranasal sinusitis. Morphologic study revealed
cylindrical dilatation of the terminal bronchioles. Interstitium of terminal
bronchioles, alveolar passages alveoli infiltrated "frothy" lymphoid cells
.

By fibrosis develops tsentrilobulyarnaya emphysema [8]. CT
determined by bilateral, diffuse and small focal linear seal (as
tsellyulyarnoy in the form of bronchiolitis), thickening of the walls of small bronchioles, dilatation
lumen field "ground glass" on the periphery of the lung alternating with areas of
tsentrilobulyarnoy emphysema. Affected virtually all light (Fig. 5).

Fig. 5. CT - peribronchial fibrosis, emphysema tsentrilobulyarnaya symptom
"matte" tsentrilobulyarnye foci.

Differential diagnosis

Differential diagnosis of bronchiolitis is conducted with allergic alveolitis
( hypersensitive pneumonitis), under which it is also possible
identifying small focal changes in lung tissue. However, they are localized in
alveoli, diffuse, homogeneously distributed in the lung. Typically, the clinical picture is caused by inhalation of
sensitizing antigen.

As stated above, bronchiolitis obliterans in the propagation of polyposis
the alveoli leads to the development OBOP. Focal infiltrative changes in lung
along the bronchi to form a symptom of "air bronhogrammy" reaction
pleural thickening as it allows to distinguish with bronchiolitis.

"variegated" pattern of lung tissue can arise not only from constrictive bronchiolitis
, but also in other types of pulmonary hemodynamics -
chronic pulmonary thromboembolism, pulmonary hypertension. Differential
diagnosis based on clinical data, medical history.

Conclusion

Thus, computed tomography, especially in the modification of HRCT for
today's leading method for diagnosing lesions distal
respiratory tract, diagnosis, type of lesion, prevalence, violations
ventilation dynamics of the process. Conventional radiography plays a supporting role in
indicative assessment of lung microstascture,
differential diagnosis with other diseases, monitoring of the dynamics
disease.

References

1. Avdeev OE et al Chronic obstasctive pulmonary disease, Ed.
Chuchalin AG M., 1998. 462 with.

2. Garg K. et al. / / Amer. J. Roentgenol. 1994. V. 162. P. 803.

3. Kitaev VV Med. visualization. 1997. № 4. P. 21.

4. Kotlyarov PM / Eng. med. Journ. 2001. T. 9. № 5. S. 197.

5. Kotlyarov PM, Georgiadi SG Med. visualization. 2002. № 3. P. 46.

6. Yudin, AL et al Radiology - Practice. 2000, October. C. 10.

7. Hartman T. et al. / / Radiographics. 1994. V. 14. № 5. R. 991.

8. Yamanaka A. et al. / / Naika. 1969. № 23. P. 442.