====== RADIOLOGY ====== * [[:en:skull_radiology | SKULL RADIOLOGY ]] * [[:en:chest_radiology | CHEST RADIOLOGY ]] * [[:en:abdomen_radiology | ABDOMEN RADIOLOGY ]] * [[:en:pelvis_radiology | PELVIS RADIOLOGY ]] * [[:en:upper_limb_radiology | UPPER LIMB RADIOLOGY ]] * [[:en:lower_limb_radiology | LOWER LIMB RADIOLOGY ]] * X rays * high density tissues * absorb x rays * radio-opaque * cast a white shadow * like * bone * calcium rich tissues * low density tissues * transmit x rays without absorption * radio-lucent or radio translucent * depending on the gray scale of absorption of different materials * black shadows * grey shadows * like soft tissues which contain * fibers and cells * examples * muscles * fascia, tendons , ligaments * vessels * nerves * Grey shadow * water or fluid ( LESS ) * fat ( LESSER ABSORPTION ) * total black shadow * air ( LEAST ABSORPTION ) * lungs * Total black shadow * Formation of Human X ray image * Parts present behind bone * gets minimal exposure to x rays * Properties of X rays * Penetration * lower atomic weight * transmit x rays * higher atomic weight * absorb the x rays * photographic property * bromium salt * applied as an emulsion on x ray film * film * procedure is called radiography * photo or film is called skiagram( shadow writing) or radiogram * fluorescence property * light waves are produced when x rays strike * phosphorous salts * biological properties * can destroy abnormal cells * without destroying normal cells to a certain degree * Radiographic views of a photo * anteroposterior view * X ray tube placed anteriorly * X ray film placed posteriorly * uses * in abdomen kidneys and lumbar vertebra are more posteriorly * AP view used * posteroanterior view * X ray tube placed posteriorly * X ray film placed anteriorly * uses * in heart is more anteriorly hence * PA view is used * Lateral view * Right lateral or left lateral x ray tube * X ray film lateral * Oblique view * Radiological appearances * Bones * white shadow * homogenous * compact bone * inner and outer tables of skull * irregular * represent lamellae * spongy bone * middle table of skull * cancellous bone * grey shadow * medullary cavity * CONTRAST RADIOGRAPHY * for digestive system * barium swallow * esophagus * barium meal * stomach * barium meal follow * small intestine * barium enema * large intestine * for salivary ducts * sialography * for extrahepatic bilary apparatus * cholecystography * for tracheobronchial tree * bronchography * for urinary system * descending and ascending pyelography * for female reproductive system * hysterosalpingography * for subarchnoid space around spinal cord * myelography * for ventricles of brain * ventriculography * for vessels * angiography * arteriography * aortography * cerebral angiography * carotid angiography * coronary angiography * pulmonary angiography * renal angiography * ophthalmic * fluorescent angiography * venography * lymphangiography * CRITERIA * PRE PROTOCOL * allergy to medicines * CONTRAST MEDIUM * criteria for selection * easily available * non toxic * types * air * barium sulfate * sodium iodide * fluoroscopy * mammography * types * positron emission mammography * principle * gamma radiation * types based on photo * screening mammogram * diagnostic mammogram * ultrasound * principle * form of energy in the for of waves * not audible are called ultrasound waves * types * doppler ultrasonography * types * transcranial doppler * doppler echocardiography * uses * non functional valves of veins * varicose veins * saphenofemoral junction reflux * decreased blood flow * blood clots * deep vein thrombosis * stenosis * peripheral arterial disease * aneurysm * 3D and 4D ultrasound * instrument * wave producer or ultrasound transducer * types * surface * internal * process * wave produced by transducer * penetrate soft tissues * reflected back as echoes * received by transducer * recorded * displayed as * sonogram * NEW IMAGING TECHNIQUES * TOMOGRAPHY * COMPUTED AXIAL TOMOGRAPHY * OPTICAL COHERENCE TOMOGRAPHY * CONTRAST COMPUTED TOMOGRAPHY * POSITRON EMISSION TOMOGRAPHY * MAGNETIC RESONANCE IMAGING OR NUCLEAR MAGNETIC RESONANCE * principles * magnetic bars * internal magnetic bars * atoms inside body * absorb radio waves * protons get excited * protons are the hydrogen ions of water present in tissues of body * external magnets * MRI machine * very large magnet * create a magnetic field roughly 25000 times stronger than earths magnetic field * Appearance * fat , subcutaneous tissue appears as * white shadows * bone appears as * dark shadows or black shadow * soft tissues appearance * vary depending upon procedure * based on procedure * T1 and T2 weighted MRI * advantages * edema or hemorrhage * cannot be seen with CT , can be seen with MRI * Investigation of choice in Multiple sclerosis * CONTRAST MRI * MAGNETIC RESONANCE ANGIOGRAPHY * FUNCTIONAL MAGNETIC RESONANCE IMAGING