Overview: Radiography + Med. Imaging Flashcards Preview

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Flashcards in Overview: Radiography + Med. Imaging Deck (33)
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1

Radiology Principles (3)

1. Based on ability of x-rays to penetrate tissues and organ

2. Rate of penetration depends on organ/tissue density - Greater density = opaque image - Lesser density = transparant image

3. All radiation studies involve some exposure to harmful radiation, choose scans wisely

2

Radiography presentations of body structures (5)

1. Healthy bones = white

2. Bone fx = radiolucent line

3. Osteoporotic bone = gray/porus

4. Healthy lung/bowel = black

5. Other structures (musc/bld/organ/misc tissues) = black

3

Radiography views (3)

1. AP = x-rays pass front → back

2. PA = x-rays pass back → front

3. Oblique = x-rays pass @ angle

4

Types of radiography studies (3)

1. Plain films

2. Fuoroscopy

3. CT scan

5

Define Fluoroscopy

  • Fluoroscope used to visually examine target
  • Utilizes the following tools:
    • X-ray source
    • Fluorsecent screen
  • More radiation exposure than plain film
  • Allows for real time images

6

Define CT Scan

  • Integrated view of multi-angled x-rays
  • Each x-ray represents a "slice," selection of tissue @ specific level
  • Variation of density allows for variable penetration
    • Permits exam. of tissue that would otherwise obscure due to surroundings
    • Presents with various shades of black/gray on images 

7

Plain x-ray indications (5)

Suspision of the following:  

  1. Trauma/injury
  2. Infection
  3. Tumor
  4. Arthritis
  5. Bone spurs

8

Spinal x-ray indications (5)

Suspicion of the following 

  1. Trauma
  2. Degenerative changes
  3. Tumor mets
  4. Spondylollithesis
  5. Scoliosis

9

Define Spondylolithesis

Slipage of 1 vertebral disc over another, causing vertebral column dysfunction 

10

Chest x-ray Indications (5 structures, 8 general conditions)

Evaluate...

  1. Heart
  2. Lungs
  3. Bony thorax
  4. Mediastinum
  5. Great vessels

For these conditions

  1. Tumors
  2. Infections
  3. Pleural fluid
  4. Pulmonary edema
  5. COPD
  6. Pneumothorax
  7. Rib fx
  8. Thoracic vert. fx

11

General Kidney, Ureter, Bladder x-ray (KUB) Indications (3)

  1. Intestinal obstruction
  2. Soft tissue masses
  3. Ruptured viscus

Note: Often the most cost effective measure for ruling in GI/GU pathology

12

Abdominal CT Indications (3 general, 1 c 8 common examples)

  1. CT-guided needle biopsy
  2. Diagnosing/staging neoplasms
  3. Monitor and diagnose abdo disease
    • Abcess
    • Inflammation
    • Perforated bowel
    • Intestional obstruction
    • Calculi
    • Tumors (adrenal, liver, pancras)
    • Pseudocysts
    • Trauma (esp. splenic hematoma)

13

Brain CT Indications (7)

Diagnosis of the following

  1. Brain tumor
  2. Cerebral infarction
  3. Ventricular displacement/enlargement
  4. Cortical atrophy
  5. Bleeding/AV malformation
  6. Hematoma
  7. MS

14

Chest CT Indications (6)

Aid in the diagnosis of the following pathologies, esp when CXR dues not suffice

  1. Tumor
  2. Nodule
  3. Abcess
  4. Pleural effusion
  5. Enlarged lymph nodes (often in the presence of lung and mediastinum dysfunction)
  6. Pulmonary embolism (via spiral CT)

15

Spiral CT (definition, 2 major uses)

Definition: CT scan technique involving continuous movement of pt through the CT scanner. Allows faster scanning c incrased definition of internal structures

Uses: Visualization of the following

  1. Blood vessels 
  2. Internal tissues

16

Ulrasound Principles (3)

  1. High frequency sound waves directed @ internal body structures
  2. Recording of impulse intensity reflects back through tissues
  3. Differentiates b/w acoustic densities of solid and cystic structures, thus readily used for discerning cyst vs tumor

17

Ultrasound Advantages (3)

  1. Noninvasive 
  2. No ionizing radiation
  3. Less expensive than CT or MRI

18

Ultrasound Procedure (5 steps)

  1. Skin overlaying indicated area coated c lubricating gel
  2. Sonographer specifically directs probe (as transducer) at angles corresonding with structure of interest
  3. Transducer emits directed sound waves at tissue
  4. Echos converted received by probe (as receiver) convert to electrical images that are displayed visually on a screen

19

Types of US orders (8)

  1. Abdominal
  2. Breast
  3. OB
  4. Pelvic
  5. Prostate
  6. Scrotal
  7. Transesophageal Ecocardiogram (TEE)
  8. Transthoracic Ecocardiogram (TTE)

20

Abdominal US Uses (5 organs, 6/1/4/2/4 pathologies)

  1. Kidney
    • Cyst
    • Tumor
    • Calculi
    • Hydronephrosis
    • Abcess
    • Ectopic kidney
  2. Abdominal Aorta
    • Aneurysm (most cost effective for minor AAA)
  3. Liver
    • Cyst
    • Abscess
    • Dilated hepatic duct
    • Tumor
  4. Gallbladder
    • Gallstones
    • Polyps
  5. Pancreas
    • Tumor
    • Pseudocyst
    • Inflammation
    • Abscess

21

Breast US Uses (4)

  1. Differentiate b/w cystic and solid lesions
  2. Identify BC masses too dense for accurate mammography
  3. Monitor cyst progression/regressino
  4. Evaluation in conjunction c mammogram

22

OB US uses (2 categories, 8/3 specifics)

  1. Pregnancy 
    • Early confirmation/diagnosis of pregnancy
    • ID multiples
    • Differentiate normal pregnancy from hydatiform mole
    • Determine fetal age (from head diameter)
    • Measure fetal growth
    • ID placental abnormalities
    • Determine fetal position
    • Diagnose ectopic pregnancy
  2. Pathology
    • Neoplasm
    • Cyst
    • Abscess

23

Pelvic US Uses (7)

Aid in the diagnosis of the following:

  1. Ovarian cyst
  2. Ovarian tumor
  3. Tubo-ovarian abscess
  4. Uterine fibroid
  5. Uterine cancer
  6. Pelvic Inflammatory Disease (PID)
  7. Endometrial thickness

24

Prostate/Rectal US Uses (3)

  1. Evaluate pts with elevated prostatic surface antigen (PSA)
  2. Evaluate prostate size/contour/consistency
  3. Diagnose prostate cancer in the context of the following
    • Positive digital rectal exam (DRE)
    • Elevated PSA

25

Scrotal US Uses (7)

  1. Eval. scrotal mass
  2. Eval. scrotal trauma
  3. Eval. scrotal pn
  4. Measure testicular size
  5. Eval. testicular neoplasm
  6. Survey pt c previous primary or metastatic testicular tumor
  7. Localize undescended testicle

26

Transesophageal Echocardiograpm, TEE

(Procedure, General Use, Advantage) 

Use: Provide info about heart muscle, valves, and general function

Procedure: Endoscopically place transducer in distal esophagus or proximal stomach to transmit sound waves closer to target heart tissue

Advantages: Proximity allows for better resolution than typical or TTE US techniques

27

TEE Uses (6)

  1. Mitral valve visualization
  2. Differentiate b/w intracardiac and extra cardiac masses
  3. Atrial septum visualization (for ASD)
  4. Diagnose thoracic aortic dissection
  5. Detect valvular vegetation indicative or endocarditis
  6. Determine cardiac sources of arterial emboli

28

Transthoracic Echocardioagram, TEE Uses (4)

  1. Evaluate heart wall motion
  2. Detect valvular disease (but not as well as TEE)
  3. Evaluate heart during stress testing
  4. Identify and quantify pericardial fluid 

29

MRI Advantages (2)

  1. No exposure to ionizing radiation
  2. Comparatively high level of contrast b/w normal and pathologic tissue

30

MRI MOA

MRI sends radiofrequencies into tissues which changes the magnetic field. Machine measures distrubance/behavior of H+ atoms when exposed to this change in magnetic field