Prophylaxis of rheumatic fever

 American Heart Association Recommendations for Duration of Secondary Prophylaxisa 

 Rheumatic fever without carditis 

DURATION OF PROPHYLAXIS 

For 5 years after the last attack or 21 years of age (whichever is longer) 

Rheumatic fever with carditis but no residual valvular disease 

For 10 years after the last attack, or 21 years of age (whichever is longer) 

Rheumatic fever with persistent valvular disease, evident clinically or on echocardiography 

For 10 years after the last attack, or 40 years of age (whichever is longer); sometimes lifelong prophylaxis

Penetration and Exposure in Chest Xray

 Penetration is assessed by visualising  the lower thoracic vertebral bodies, whose outline should just be visible through the heart  on a PA projection

If  the outline of  spine cannot be visualised  through the heart, the film is underpenetrated

In underpenetrated film,pulmonary vessels and interstitial markings appear more prominent, loss of detail at the lung bases and vertebrae, results in increased density.

Strap muscles of neck

 Strap muscles of neck

Sternohyoid

Sternothyroid

Thyrohyoid

Omohyoid

Pulsus Paradoxus - Measurement

 For patients without an indwelling arterial access, pulsus paradoxus is best measured with a manual sphygmomanometer and stethescope. Automatic blood pressure cuffs cannot accurately measure pulsus paradoxus. 

Assessment is made by inflating the cuff until all Korotkoff are absent, then very slowly releasing pressure from the cuff. The first sounds auscultated will be heard only during expiration, and this pressure should be noted. Next, as cuff pressure is dropped further, the pressure should be noted when Korotkoff sounds are heard during both inspiration and expiration. The variation between these 2 systolic pressure is what quantifies pulsus paradoxus. 

Dyspnea- Causes of Acute Dyspnea

 1. Pulmonary edema

2. Asthma

3. Injury to chest wall and intrathoracic structures

4. Spontaneous pneumothorax 

5. Pulmonary embolism 

6. Pneumonia 

7. Adult Respiratory distress syndrome 

8. Pleural effusion 

9. Pulmonary hemorrhage

10. Foreign body aspiration

11. Vocal cord dysfunction 

Hydatid cyst- Radiological signs

 1.Crescent sign

2. Inverted Crescent sign

3. Cumbo (Onion peel, double arch) sign

4. Water lily (Camalote) sign

5. Empty cyst sign

6. Serpent (snake) sign

7. Spin (whirl) sign

8. Ball of wool (yarn) sign

9. Honeycomb pattern (wheelspoke, rosette, racemose)

10. Double line sign 

Air crescent sign and Monod sign

 Air crescent sign also known as Meniscus sign or Cap sign, appears on xray or CT of the chest as air interposed between an intracavitary ball like mass and the cavity wall.

Most common cause is fungal ball of invasive aspergillosis. Other causes are pulmonary hydatid cyst, other fungi, blood clot or Rasmussen aneurysm in a tuberculous cavity, lung abcess with inspissated pus, staphylococcal pneumonia, nocardial infection, carcinoma of the lung, pulmonary gangrene or hematoma.

In aspergilloma, this mass usually moves within the cavity when the patient changes position and the sign is called Monod sign. A CT scan of the chest can be performed in prone position and if the mass moves to dependent area, diagnosis can be confirmed.

SILHOUETTE SIGN

The phenomenon of the loss of the normal radiographic silhouette (contour) when two substances of the same density are in direct contact is called Silhouette sign.

Right heart border  silhouette sign- RML lesion

Left heart border silhouette sign - Lingular lesion

Descending Aorta and Left Diaphragm - Left lower lobe

Right Diaphragm- Right Lower lobe

Upper Right tracheal lung interface  and Ascending Aorta- Right Upper lobe

Left atrium ,aortic knuckle,Upper Left tracheal lung interface - Left Upper lobe

Reference: Felson’s Principles of Chest Roentgenology ,5th edition