Fissure

blue dotted lines–right and left major fissures (oblique fissures),
red line–minor fissure (horizontal fissure)

Diffuse tiny nodule / Miliary

diffuse tiny nodules (less than 5 mm) other than TB

1. Miliary fungal disease (histoplasmosis, coccidioidomycosis, blastomycosis, cryptococcosis),
2. varicella pneumonia,
3. hematogenous metastatic malignancy (especially tumors of the thyroid, kidney, breast, and pancreas, and choriocarcinoma and melanoma),
4. bronchioloalveolar carcinoma,
5. lymphangitic tumor and lymphoma,
6. silicosis and other pneumoconioses, sarcoidosis, and eosinophilic granuloma [1].

Very rare causes include hemosiderosis, alveolar microlithiasis, amyloidosis, hypersensitivity pneumonia, nocardia, and bronchiolitis.

• Multiple, fine, pinpoint (< 2 mm.)
– จากการทํา lymphogram
– สูดสารบางชนิดเข้าปอด เช่น hair spray, talc, barium

• Small nodular (3-5 mm.)
– TB, Histoisplasmosis, coccidioidomycosis
– bone formation จาก mitral value disease
– chicken pox
– microlithiases
– Talc, iron, barium

• Soft tissue density (2-5 mm.)
– Miliary fungi
– Hemosiderosis
– miliary metastasis
– pneumoconiosis
– sarcoidosis
– acute extrinsic allergic alveolitis

Bleb Bullae Cyst

BLEB

1 cm
-Pathology.—An airspace measuring more than 1 cm usually several centimeters in diameter, sharply demarcated by a thin wall that is no greater than 1 mm in thickness. A bulla is usually accompanied by emphysematous changes in the adjacent lung.
-Bullae may contain nothing but gas or may contain overdistended and ruptured alveolar septa and blood vessels
Radiographs and CT scans.—A bulla appears as a rounded focal lucency or area of decreased attenuation, 1 cm or more in diameter, bounded by a thin wall.Multiple bullae are often present and are associated with other signs of pulmonary emphysema

CYST

-Pathology.—A cyst is any round circumscribed space that is surrounded by an epithelial or fibrous wall of variable thickness (51).
-Radiographs and CT scans.—A cyst appears as a round parenchymal lu- cency or low-attenuating area with a well-defined interface with normal lung. Cysts have variable wall thickness but are usually thinwall (<2 mm) and occur without associated pulmonary emphysema (Fig 21). Cysts in the lung usually contain air but occasionally contain fluid or solid material. The term is often used to describe enlarged thin walled airspaces in patients with lymphangioleiomyomatosis (52) or Langer- hans cell histiocytosis (53); thicker walled honeycomb cysts are seen in patients with end-stage fibrosis

EMPHYSEMA

-Pathology.—Emphysema is characterized by permanently enlarged airspaces distal to the terminal bronchiole with destruction of alveolar walls (42,43). Absence of “obvious fibrosis” was his- torically regarded as an additional crite- rion (42), but the validity of that criterion has been questioned because some interstitial fibrosis may be present in emphysema secondary to cigarette smoking (56,57). Emphysema is usually classified in terms of the part of the acinus predominantly affected: proximal (centriacinar, more commonly termed centrilobular, emphysema), distal (paraseptal emphysema), or whole acinus (panacinar or, less commonly, panlobular emphysema).
-CT scans.—The CT appearance of emphysema consists of focal areas or regions of low attenuation, usually without visible walls (58).presenting bronchovasular bundle in central area. In the case of panacinar emphysema, decreased attenuation is more diffuse

Miliary TB in HRCT

 

Miliary TB HRCT เห็นเป็น Random pattern (hematogenous spead)
แต่ถ้าเป็น broncho speading TB จะเป็น tree in bud or centrilobular

Azygous width

The width of the azygos arch is measured perpendicularly to the trachea in the greatest transverse dimension. Measurement includes the wall of the trachea.
Dilation of the azygos vein is a sign of increased right atrial pressure and is usually seen when there is also an increase in the width of the vascular pedicle.
The diameter of the azygos vein varies according to the positioning.
In the standing position a diameter > 7 mm is most likely abnormal and a diameter > 10 mm is definitely abnormal.
In a supine patient > 15 mm is abnormal.
An increase of 3 mm in comparison to previous films is suggestive of fluid overload.
The difference of the azygos diameter on an inspiration film compared to an expiration film is only 1mm.
This means that the diameter of the azygos is a valuable tool whether or not there is good inspiration.

Stage of CHF in CXR