Radiology reviewII. Adequate CXR1. Penetration: see spine through heart2. Inspiration: at least 8-9 posterior ribs3. Rotation: spinous process between clavicles4. Angulation: clavicle over 3rd rib-PA: heart is closer to film = less magnified. AP = heart is farther away = more magnified.

III. Cardiomegaly1. CT ratio < 50% EXCEPT:-portable AP film, obesity, pregnant, ascites, straight back syndrome, pectus excavatum. May also appear larger with expiration.-if the heart touches the lateral chest wall, it is enlarged

IV. Causes of an Opacified Hemithorax1. Atelectasis: lose volume, therefore heart and hemidiaphragm shift toward side of opacification.2. Large pleural effusion: acts like a mass, therefore heart and trachea get pushed away from the affected side.3. Pneumonia of an entire lung: no shift. may have air bronchogram.4. Post-pneumonectomy: volume loss but fills with fibrosis. Look for clips +/- loss of 5th rib.

V. Pleural Effusion-Normal = 2-10cc fluid in pleural space produced at parietal pleura and removed via lymphatics by visceral pleura.-Transudate vs exudateTransudate: increased capillary hydrostatic pressure or decreased osmotic pressure.Exudate: neoplasm or inflammatory disease-[fluid protein]/[serum protein] > 0.5-[fluid LDH]/[serum LDH] > 0.6-fluid LDH > 2/3 highest normal serum LDH-Left vs right sideLeft side: pancreatitis, Dresslers syndrome, distal thoracic duct obstructionRight side: heart failure, abdominal disease, proximal thoracic duct obstruction

VI. Congestive Heart Failure-Pulmonary interstitial edema: kerley B lines (distended interlobular septa), peribronchial cuffings (distal to hilar area), thickening of the fissures (fluid in subpleural space), pleural effusions. Need LA pressure 20-25 mmHg.-Pulmonary alveolar edema: butterfly configuration. Clears up in 5 cm from carina

Tracheostomy way between stoma and carina

Central venous catheterSVC

PICCSVC

Swann-GanzProximal R or L pulmonary artery

Pleural drainageAnterosuperior for ptx; posteroinferior for effusion

PacemakerApex of RV, others in RA and/or coronary sinus

AICDOne lead in SVC, other in RV

NG tubeStomach

XIII. SBO, LBO and ileusAir in rectum/sigmoidAir in small bowelAir in large bowel

Local ileusYes2-3 distended loopsRectum or sigmoid

General ileusYesMany distended loopsYes- distended

SBOYesMany dilated loopsNo

LBOYesNone unless incompetent ileocecal valveYes- dilated

-Localized ileus: sentinel loops.-Generalized ileus: postop pts. Bowel sounds absent or hypoactive.

XIV. Free air-3 major findings: air beneath the diaphragm, falciform ligament sign, air on both sides of bowel.-MCC: perforated ulcer

XV. Abdominal calcifications-Patterns-Rim-like: wall of a hollow viscus-Linear or track: walls of a tube-Lamellar: lumen of hollow viscus -Cloudlike: solid organ or tumor

XVI. Abdominal soft tissue masses-Bowel displacement: paucity of gas in an area or abdomen normally containing bowel.-Pad sign: extrinsic impression on a loop of bowel-Edge of a soft tissue mass

XVIII. Disclocations and fractures