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INTERACTIVE CASE DISCUSSIONS. Medical Clerkship Department of Radiological Sciences. 30/F CC: cough. CASE 1. HISTORY OF PRESENT ILLNESS. (+) cough (+) difficulty of breathing (-) fever Persistence. VS HR 120/80 HR 96 RR 28 T 36.4°C
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INTERACTIVE CASE DISCUSSIONS Medical Clerkship Department of Radiological Sciences
30/F • CC: cough CASE 1 HISTORY OF PRESENT ILLNESS • (+) cough • (+) difficulty of breathing • (-) fever • Persistence. • VS HR 120/80 HR 96 RR 28 T 36.4°C • in respiratory distress, supraclavicular, intercostal and subcostal retractions • symmetric chest expansion, BS left lower lung, (+) coarse crackles & rhonchi, L • 1 wk PTC PHYSICAL EXAMINATION Consult.
CHEST X-RAY AP SUPINE LEFT LAT DECUBITUS CLERK’S GUIDE: Discuss first the basics of a normal chest x-ray.
CC: Cough • action of the body takes to get rid of substances that are irritating the air passages • occurs when mechanical or chemical afferent nerves get irritated and trigger a chain of events • Air in lungs is forced out under high pressure.
Analysis • Cough • Acute < 3weeks • Persistent >3weeks • Chronic >8weeks • Acute cough • Infectious • Non infectious
Indications for a Chest X-ray For patient with acute cough • Abnormal vital signs • Chest examination suggestive of pneumonia Patient: RR 28 • in respiratory distress, supraclavicular, intercostal and subcostal retractions • symmetric chest expansion, BS left lower lung, (+) coarse crackles & rhonchi, L
AP supine • if px can’t assume upright position, though • can’t critically evaluate the size of the heart because of hypoventilation, diaphragmatic elevation pushing the base of the heart upwards.
Lateral Decubitus position • px lies on right or left side; the beam traverses the body in horizontal position • pxw/pleural effusion, pneumothorax – presence of fluid gravitates to dependent portions • demonstrate fluid levels in cavities
Chest anatomy: Evaluation • Ribs • Anterior ribs • obliquely placed • wider intercostals spaces • Posterior ribs • horizontally placed • narrower intercostals spaces • Intercostal Spaces
Chest anatomy: Evaluation • Diaphragm: right and left • middle segment partially obscured • Normal level • 10th post rib / 5th ant rib • right higher than the left (liver) • dome-shaped • Costophrenic angle / sinus and Cardiophrenic angle • Sharp, well defined and not blunted
Chest anatomy: Evaluation • Trachea and mediastinum • radioluscent: means it has an air • bifurcates at T5 (carina) into right and left bronchus • normal: midline • right bronchus: shorter and more vertical • left bronchus: longer and more horizontal
Chest anatomy: Evaluation • Hila, bronchovascular markings • pulmonary artery and vein • bronchial artery and vein • bronchus • lymph nodes • Normal: • left hilum higher than the right • pulmonary artery crosses above the left and below the right bronchus • size of hilum varies depending on pulmonary blood flow
Chest anatomy: Evaluation • Lungs • Radiolucent • Inner, middle, outer zones • Inner zone: from sternoclavicular joint draw a vertical line following contour of the chest, big blood vessels are located • middle zone: medium blood vessels are located • outer zone: junction of the clavicle and 1st rib draw a vertical line; small blood vessels are located
Chest anatomy: Evaluation • Upper, middle, lower lung fields • landmarks: 2nd and 4th anterior ribs • upper lung field: further subdivided by the clavicle into supraclavicular (apex) and infraclavicular • significance: for localization of the lesions
Chest anatomy: Evaluation • Lobar anatomy • right lobe • major fissure: divides lower lobe from upper and middle • minor fissure: divides upper and middle • left lobe • for upper and lower lobes only
Chest anatomy: Evaluation • Heart shadow • Superior mediastinum • draw a line from the sternal angle to the 4th vertebra • Anterior mediastinum • bounded by posterior surface of the sternum and anterior surface of the heart • Posterior mediastinum • bounded by posterior part of the heart and anterior spinal muscle S A P
Chest anatomy: Evaluation • Size • Cardiothoracic ratio • Easiest gross determination • Compare size of the heart with the thorax • Normal 2:1 • Get the widest transverse diameter of the heart compare with the widestinternal transverse diameter of the thorax • Shape • Variable • neonate: globular
Chest anatomy: Evaluation • Right border • Superior vena cava • Right atrium • Inferior vena cava
Chest anatomy: Evaluation • Right border • Superior vena cava • Right atrium • Inferior vena cava • Left border • Aortic knob • Main pulmonary trunk • Left ventricle
Lateral View trachea AORTA Main Pulmonary Artery RS • Left atrium • Left ventricle Right ventricle RC
CHEST X-RAY AP SUPINE LEFT LAT DECUBITUS CLERK’S GUIDE: Discuss first the basics of a normal chest x-ray.
Patient’s chest xray • Obscured diagphragmaticsulci at the left • Narrow intercostal space • No shifting of the mediastinal structures Cardiac shadow not appreciated • Hyperluscency of the right lung • Homogenous opacification of the left lung
Radiographic Differentials • Consolidation • Atelectasis • Pleural effusion • Mass lesions
Atelectasis • means “lack of stretch” • refers to collapse or loss of lung volume • 2 types: Obstructive or Non obstructive
Atelectasis • Obstructive • blockage of an airway • Air retained distal to the occlusion is then resorbed from nonventilated alveoli • affected regions become totally airless • Non obstructive • caused by loss of contact between the parietal and visceral pleurae, parenchymal compression, loss of surfactant, or replacement of lung tissue by scarring or infiltrative disease.
Direct signs • displacement of fissures • increased opacification of the airless lobe. • Indirect signs • displacement of hilar structures, • cardiomediastinalshift toward the side of collapse, • narrowing of ipsilateralintercostal spaces, • elevation of the ipsilateralhemidiaphragm, compensatory hyperinflation and hyperlucency of the remaining aerated parts of the lung, and • obscuring of structures adjacent to the collapsed lung, such as the diaphragm, heart, or pulmonary vessels.
ROLE OF MAGNETIC RESONANCE IMAGING • can distinguish between obstructive and nonobstructiveatelectasis • Obstructive atelectasis • displays high signal intensity on T2-weighted images due to proton-rich mucus accumulation. • Nonobstructiveatelectasis • low signal intensity on T1 and T2 weighted spin-echo images, since the residual alveolar gas has a low proton concentration, and magnetic susceptibility effects between alveolar walls lead to a decrease in signal. The use of MRI in diagnosing atelectasis is still experimental, and more experience needs to be accrued
Treatment • Continuous positive airway pressure (CPAP) • Fiberopticbronchoscopy for the extraction of secretions • Mucolytic therapy