Lecture 20: Intro to Radiographic Imaging Flashcards
xray
plain radiograph
xrays pass through tissue; more or less pass based on density
more dense structures= more white; less dense= less white
radiation!
fluoroscopy
moving/continuous xray, often w/ contrast agent
radiation!
i.e. intestine imaging
CT
similar to radiograph, but xrays pass through body in 360 directions from rotating source; used to generate slices through tissue
radiation!
CT angiogram/angiogram
visualize coronary arteries
why not to do xray on pregnant woman
early in preg: can cause teratogens as organogenesis occurs
late in preg: can radiate bone marrow which can cause leukemia/cancers in childhood
MRI
uses body’s intrinsic magnetic properties to create image
spinning water hydrogen proteon is mini magent in larger magnet, the MRI scanner
cannot use on pt with metal in body
no radiation!
ultrasound
uses high frequency sound waves; different tissue reflect back more/less sound waves which are “detected” by transducter and images are generated
portable, in “real time”
no radiation!
fundamental principle of xray and CT
density - whitist to blackist, bone/metal - soft tissue - fat - air
orthogonal projections’ abilities
help to localize objects, identify pathology
neumoperitoneum
appears as asymmetry in thorax- air in peritoneum
2 parts of anatomy of thoracic cavity
pleural cavities, mediastinum
contents of pleural cavities
pleura- made up of lfat layer of mesothelial cells and uspporitng tissues
lungs- respiratory organs
2 layers of pleura
parietal layer- lines inner surface of chest cavity; visceral layer- covers surface of lungs
pleural reflections-recesses
areas of pleural spcae where there’s no visceral pleura/lung between the 2 parietal layers
place where fluid first accumulates
costodiaphragmatic recess (CP angle)
largest pleural space, where no visceral pleura/lung between 2 parietal layers, so 2 parietal layers meet; fluid can accumulate here
cannot see costophrenic angle if fluid accumulates
pleural effusion
when fluid accumulates in pleural space
pt will present w/ shortness of breath
pneumothorax
pleural air - air in lung
pt will present w/ acute onset shortness of breath
ie if person gets stabbed
pt’s lung will collapse
why lung isn’t collapsed in chest
negative interthoracic pressure
how to treat pneumothorax
chest tube- causes lung to reexpand itself
insert in 2nd intercostal space
hydroneumothorax
blood and air in thorax because of acute trauma
tension pneumothorax
air only goes IN- one way communication w/ atmosphere
dual blood supply to lungs
pulmonary arteries - blood from RA-RV-MPA-Rt and Lt PAs = deoxygenated blood
bronchial arteries- blood from aorta/branches = oxygenated blood
pneumonia
opacity in lung
pt will present with coughing with sputum, fever, elevated WBC count
mediastinum contents
thymus, heart in pericardial sac, major vessels, trachea, esophagus, nerves and lymphatics
heart position in chest - 3 moves
apex points down, forward and to the left
base sits over diaphragm w/ right more forward than left
major vessels enter/exit posteriorly at base
heart margins on CXR
right heart border- SVC, RA, IVC (NOT RV- HEART IS ROTATED!)
left heart border- aortic arch, pulmonary trunk, LA, LV
pericardial effusion can look like
an abnormally big heart- cardiomegaly
superior mediastinum contains
R and L braciocephalic veins
thoracic aorta and major branches
superior vena cava
trachea
esophagus
thymus
phrenic and vagus nerves
left recurrent laryngeal nerve (passes under arch)
destocardia
heart reversed in chest if heart tube bends wrong way during embryological development
at inlet level, how many holes do you see in superior mediastinum
5
svc syndrome
large mass narrows superior vena cava
pt presents with: rapid heart rate; bilateral neck, face, arms swollen
pericarditis
inflammatory process of pericardium
pulmonary embolism
blood clots in R and L pulmonary arteries
phrenic nerve supplies/root value
diaphragm/ C3, 4, 5
