PC 3 - Test 2 - Sheet1 Flashcards
System for reading X-rays
BSOO - bones, soft tissue, organs, and other
Before reading an x-ray, it is essential to…
Make absolutely certain that you have the right film for the right patient and it is turned the right way. Also, make sure the film is correctly dated.
What to do if the film is of poor quality
Have it repeated
Number of views mandatory of x-rays
Two views. Three or more for certain body parts
Views of out-patient chest x-rays
PA and lateral
PA versus AP chest x-ray views
PA is out-pt and AP is in-pt (often with pt lying in bed)
X-rays with fractures
X-ray the joint above and below the fracture
Information to relay to radiologist reading x-rays
Remember that the two of you are working for the pt together. Any info you can give the radiologist to correlate the history and the film is beneficial and helps to reduce the margin or error
Helpful tip for x-raying children
Often helpful to x-ray the same bone on the other side of the body in order to make comparisons.
Can you tell the patient beyond question that there is no fracture?
No because it may take days for some fractures to show up as calcification occurs
CT scan
A two-dimensional display of two-dimensional information, and objects appear where they really are in space. A large number of structures can be visualized simultaneously with a CT scan.
Radiation exposure with CT
About 10-100 times more radiation than with a radiograph.
Ultrasonography
Uses high-frequency sound waves to make images by sending the the high-frequency waves and assessing the echoes they return.
Echos of an ultrasound
The result of interfaces or changes or density between tissues.
MRI
Done by applying a varying magnetic field to the body.
Primary advantage of MRI
It obtains exquisite image of teh CNS and stationary sort tissue.
Major safety problem with MRI
Magnets are very strong.
Contraindications of MRI
Cardiac pacemakers, defibrillators, spinal cord stimulators, and most aneurysm clips.
Medications and conditions to consider before ordering CT dye
Metformin, kidney status, or pregnancy
Using x-ray to diagnose
It does not stand alone, and must be considered in the context of the clinical situation
Ordering the correct x-ray
It is crucial. If in question, consult the radiologist prior to placing the order
What radiology tests to order?
Choices of what to order are based on your differential diagnoses; what is available in your area; and cost, convenience, and insurance status
How x-rays work - basics
X-ray beam is the light source. The image detector is the recipient of the light. The patient lies between the x-ray beam and the image detector.
Darkness of x-ray films
More x-ray that hits the film causes a darker image
Radiopaque
Does not permit the passage of x-rays, so the film will be white
Radiolucent
Permits the passage of x-rays, so the film will be dark
Four basic shades on a plain x-ray
X-rays are absorbed in varying amounts by different tissues or materials. Air - dark. Fat, Water. Bone - light
Air on an x-ray
Does not absorb much radiation, so more radiation passes through and strikes fluorescent screen and exposes the film. This causes the film to be dark
Fat on an x-ray
Is usually gray and darker than muscle or blood
Bone on an x-ray
White, as art calcium deposits
Metal or contrast on an x-ray
Appears white
Process of examining an x-ray
Check the name. Check the date. Look at the entire film every time. Be sure the x-ray is technically well done, showing all the expected parts.
When to repeat an x-ray
If it is not technically well done. If jewelry or anything metal shows up.
Systemiatic exam of findings on x-ray
Bones; soft tissue; organs; and other things. BSOO. Using a system prevents missing the unexpected. Compare new to old x-rays whenever possible
Looking at bones to diagnose fractures
Bones should be smooth. If it is not, it is fractured
Determing the number of views of an x-ray to order
Standard x-rays are 2 dimensional. You need at least 2 views because the human body is 3 dimensional. One view is one view too few. More views increase the likehood of finding the problem.
Why ordering different x-ray views is essential
Something could be hidden in one view; it is a matter of perspective. An object could be more difficult to see or could take on a different appearance, again based on perspective.
Types of standard views of x-rays
PosteriorAnterior (PA). AnteroPosterior (AP). Lateral (Lat). Oblique
Positioning for x-rays
It can affect magnification, organ position, and blood flow. Before interpretation, it is important to know the patient’s position
Normal view of chest x-ray
PA and lateral (PA/Lat)
Normal view of abdomen
Flat and upright
Normal view of extremity
PA/AP, lateral, oblique
Problem with ordering unnecessary views
Increases the cost and radiation exposure
Why a chest x-ray would be ordered AP view
Usually because the patient is bedridden. In this view, the heart will appear larger. So, you must know what view you are looking at.
why does the heart appear larger in the AP view?
On the PA view, the heart is closer to the film, so less shadow. In the AP views, the heart is further from the film, leading to magnification.
Diaphragm on normal chest x-ray
The right hemi-diaphragm should be 1-2 cm higher than the left
What does a paper thin diaphragm indicate
Free air in the peritoneum. Diaphragm should never be that thin.
Costophrenic angels of normal chest x-ray
Should be sharp and clear
Blood flow in normal upright chest x-ray
More blood flows to the lung bases than the apices, so the vessels should be distinct from the peripheral 1/3 of the lung back to the hila, and more evident in the lower lobes than upper lobes
Assessing a normal chest x-ray
Are the clavicles symmetrical? Count ribs - anterior ribs, posterior ribs, rib spaces - 8-10 with normal expansion and 10 or more with hyperinflation
Assessing ribs on a normal chest x-ray
Use ribs to identify where lesion(s) or problem(s) may lie. Posterior ribs are straight and attach to vertebral body. Anterior ribs angle; many attach to the sternum.
Normal cardiac silhouette diameter of normal chest x-ray
Diameter is less than 1/2 the intrathoracic diameter.
Dextrocardia
Check film for demographics to reveal is film is flipped. Films usually have left and right markers, so check them.
Atelectasis
Collapse of a portion or entire lung with the re-absorption of air from the alveoli
Bleb or bullae
Portion of the lung in which there is an air space without albeoli (bled is small, bullae is greater than 1 cm)
Infiltrate
Alveolar space is filled with pus, fluid or blood
Assessing pneumonia on x-ray
Look for infiltrates. Look for loss of sharp cardiac borders (silhouette sign)
Essential step when patient diagnosed with pneumonia
Patient must always return for test of cure x-ray to prove infiltrates are clear and to be sure the infiltrate was not the result of something else, or hiding something else.
Landmarks of miller and upper lobes
Lie against the heart
Landmark of lower lobes
Lie against the diaphragm
Infiltrates of right lower lobe pneumonia
Infiltrates will appear posterior to the heart, obscuring the T-spine
Infiltrates of right upper lobe pneumonia
Heart border disappears with lateral view, as the infiltrate will be anterior of the heart
Landmarks of left lobes of lungs
Upper lobe is anterior of the heart. Lower lobe is posterior of the heart
Pleural effusion
Fluid layering in pleural cavity. If seen on upright x-ray, they are at least 100 ml in size. Most seen in dependent portions of pleural spaces. Causes blunting of costophrenic angles. Larger effusions may compress lung tissues.
COPD on x-ray
Only detects moderate or late disease. Hemi-diaphragms may be as low as 12th posterior ribs. Causes blunting of costophrenic angles. Increased AP diameter in lateral view. Marked flattening of the sternum. Flattening of the hemi-diaphragms. May also have bullae
Chest x-ray of advanced COPD
May see hyperinflation
Appearance of air spaces with COPD
Appear dark since airspace is minimal
Early stages of CHF on chest x-rays
Minimal cardiomegaly and redistribution of pulmonary vascularity (equal upper and lower)
Fluid accumulation on chest x-ray with worsening CHF
As CHF worsens, fluid may collect in intra-lobal septa at the lateral basal aspects of the lungs AKA Kerley B lines
Blood vessels of worsening CHF on chest x-rays
Vessels in the hila become more indistinct (bilateral and symmetrical indistinctness suggests CHF)
Fluid collection on chest x-ray with CHF
As fluid accumulates in the alveolar spaces, pulmonary edema becomes evident. Blunting of the costophrenic angles results from pleural effusions.
Appearance of heart on chest x-ray with CHF
Looks like a big heart with fuzzy borders
Additional diagnostic test in patient with CHF
Order an ECG
Kerley B lines of chest x-ray with CHF
Always located inside ribs. Not to be confused with blood vessels because blood vessels should not be seen in peripheral 1/4 of lung.
What do Kerley B lines indicate
Destruction of the lymphatics. They are rarely seen, really a “lucky finding”, but somehow a frequent test question
TB on chest x-ray
Normal x-ray does not exclude active TB in other sites (kidney, spine). Infiltrates and cavitations in apices. Hilar adenopathy most often present. Healed TB may present as fibrous changes or as calcifications.
Fungal infections on chest x-ray
May present as focal infiltrates or discrete lesions, rarely a fungus ball (mycetoma).
Histoplasmosis on chest x-ray
Findings similiar to TB
Cryptococcal infection on chest x-ray
May be seen as a small cavitary lesion within the lung
Coccidiomycosis on chest x-ray
Cavitary lesions
Sarcoidosis on chest x-ray
Hilar and midiastinal adenopathy; pulmonary parenchymal disease; hilar masses; unknown etiology; more common in African Americans. Prefers the upper lobes
Cystic fibrosis on chest x-ray
Causes low, falt diaphragm; small heart; large lungs. Prefers the upper lobes
Silicosis on chest x-ray
Eggshell calcifications in hilar nodes and small nodules. Prefers the upper lobes
TB
Infiltrates and cavitations in apices. Prefers the upper lobes
Empyema
A collection of pus within the pleural space caused by: primary infection, postsurgical, and post-traumatic.
Diagnosis of empyema
CT scan to locate and confirm diagnosis
Treatment of empyema
Refer to pulmonologist
Pneumothorax
Air in the pleural space caused by trauma, can occur spontaneously, other causes such as a tumor.
Diagnosis of pneumothorax on chest x-ray
Look for area of lung with no vascularity and a think white line (visceral pleura separated from parietal pleura). Occurs in varying degrees.
Life threatening element of pneumothorax
If a large amount of air enters the pleural space - pressure forces the mediastinal structures to shift to the opposite side. This is life threatening!
Stolen lung on chest x-ray
Lung markings should be visible all the way to the periphery. No lung markings means no lung. Missing lung can be either pneumothorax, surgical removal, or cavitating lung disease.
Hemoptysis
Could be from GI or nasopharyns. Most common cause is bronchitis, but must consider neoplasm and PE.
Diagnosis of hemoptysis
Initial PA and lateral chest x-ray.
Normal x-ray and low risk for cancer related to hemoptysis
Order CT scan
Normal x-ray and high risk for cancer related to hemoptysis
Order bronchoscopy and possible CT scan. Most likely, you will be consulting or referring to a pulmonologist.
What to do if suspect a PE
Order spiral CT. If not available, order VQ scan. Plain chest x-ray usually negative, but should be ordered in the differential.
Examining the neck on x-ray
Evaluate stridor with plain x-ray, but may also need to do a CT. Consult with endocrinologist before ordering thyroid study
Examining the spine on x-ray
Lateral spine should line up. You order either cervical, thoracic, or lumbar spine.
X-ray for suspected scoliosis
Order one view of thoracolumbar spine
Cervical spine x-rays
Normal lines of contour in the C-spine should have no sharp angulation. Look for normal pre-vertebral soft tissue space widths.
Soft tissue swelling and c-spine x-rays
Soft tissue swelling alone may indicate fracture and can be spine cord threatening, so get a CT scan!
Types of x-rays to order to evaluate C-spine
Two anterior views are done after exam of lateral view is found to be free of fracture or subluxation. If major trauma is suspected, order CT or MRI.
Why order anterior view of lower c-spines with mouth closed and open
Closed - normal. Open - to view the odontoid.
What is a Snuffbox
Pain on palpation over the “snuff box” area is very suspicious for a navicular fracture. Plain films may not show fracture. Risk of aspectic necrosis: do not miss this diagnosis
Description of “an apple sitting in an cup on a saucer” with wrist x-ray
The applie is the capitate, the cup is the lunate, and the saucer is teh distal radius. If you see a moon, there is a twist in the lunate bone.
Type I = Salter Harris classification of epiphyseal fracture in children
Straight across the epiphyseal plate
Type II = Salter Harris classification of epiphyseal fracture in children
Involves a portion of the plate and a corner fracture through the metaphysis
Type III = Salter Harris classification of epiphyseal fracture in children
Involves only part of the epiphysis
Type IV = Salter Harris classification of epiphyseal fracture in children
Involves part of the epiphysis and metaphysis
Type V = Salter Harris classification of epiphyseal fracture in children
Involves direct impaction and has most serious consequences
Elbow: The fat pad sign
For trauma, order AP and oblique with elbow extended and lateral view with elbow flexed. A posterior fat pad is never normal and indicates fractures of radial head
Positive fat pad sign
Displacement of the intra articular fat pads within the elbow away from the bone indicate trauma
Knee x-rays
Order AP and lateral. Clinical exam (history and physical) is better than plain film for soft tissue injuries of knee.
Lateral view of knee x-rays
Taken with knee flexed and used to evaluate patella and determine joint effusion
AP views of knee x-rays
Used for assessing joint space narrowing and if there is calcification on the cartilage
When to order MRI of knee
Indicated when exam is inconclusive or equivocal, and ligament tear is supected
Osgood-Schlatter of knee
May appear like a fracture in the H&P, but there is no fracture
Ottawa ankle rules regarding ankle pain
If pain near malleoli and either: inability to bear weight or bony tenderness (malleolar) order ankle films
Ottawa ankle rules regarding foot pain
If mid foot pain and either: inability to bear weight or bony tenderness at navicular or base of 5th metatarsal order foot films
What to do with ankle sprains
Always check for pain at base of 5th metatarsal
What to do with ankle injuries
Always check calf tenderness to rule out proximal fibula fracture; if tender, obtain tib-fib film to rule out intra-osseous tear
What and when to recheck with ankle injuries
Recheck calf in 48 hours; if better at 48 hrs, no worries; if still painful, obtain an MRI and refer.
X-rays of abdomen
Usually order flat plate and upright
What to look for of abdominal films
Gas patterns, organ shapes and sizes, calcifications, asymmetric Psoas margins, skeleton, basilar lung abnormalities
What to look for in abdomen/KUB (kidney, ureter, bladder) films
Small bowel has fine lines that extend across the lumen. Normal not to exceed 3 cm. Looks like a stack of coins. Normal for 1-2 loops unless loops overlie area of tenderness; if tender, then presume abnormal.
Indication of large bowel abdomen/KUB films
Usually mixed with fecal material and has a bubbly appearance
Normal diameter of large bowel on abdomen/KUB films
Not to exceed 6 cm
Normal diameter of cecum on abdomen/KUB films
Not to exceed 9 cm
X-ray findings for appendicitis
Usually negative
Suspected perforation, acute abdominal pain and other tests
In addition to H&P, ECG, and labs, order PA of the chest, and supine and upright view of the abdomen.
Abdominal pain and pregnant or suspect gallbladder disease
Order ultrasound
When to order CT for abdominal pain
For non-intestinal abdominal pathology
What will ultrasound examine
Liver, kidneys, gallbladder, common bile duct, and maybe appendix and pancreas
What to order when suspect kidney stone
CT without contrast
What to order when suspect apendicitis
CT with contrast
What to order with hematuria
CT with and without contrast. Most stones will show without contrast. IVP for the young. CT if older or concern of CA
What to order with PUD
Upper GI or endoscopy (endoscopy is the gold standard)
How will vegetable and plastic show on x-ray
Usually not visible on radiograph
How will glass show on x-ray
90-95% visible
What to order for fracture
Plain x-ray
What to order for occult hip fracture
MRI
What to order for occult knee fracture
MRI
What to order for stress fracture
Nuclear medicine bone scan
What to order for metastasis-fracture
Nuclear medicine bone scan
What to order for osteomyelitis
Plain x-ray, then nuclear medicine bone scan
What to order for back pain with radiculopathy
MRI
What to order for non septic arthritis
Plain x-ray
What to order for suspect septic arthritis
Plain x-ray, plus joint aspiration
What bones are better visualized with CT
Fine bone structures, skull, spine, and pelvis.
Pro of CT scans
A large number of structures can be visualized simultaneously with a CT scan
Before ordering CT contrast
Be sure to know the renal function. There are guidelines based on creatinine levels for age and health of patients.
If renal function is questionable
Consult the radiologist and possibly the nephrologist before ordering CT with contrast
What to do with severely imapired renal function
An alternate test may be suggested other than CT with contrast
Metformin and CT contrast and decreased renal function
Beause metformin is eliminated by the kidney, impairment can lead to persistence of metformin and development of lactic acidosis. 90% is eliminated within first 24 hrs. Holding metformin for 48 hrs allows it to clear and provides an opportunity to assess any alteration in renal function caused by CT IV contrast
MRI
Uses a powerful magnetic field, radio waves and a computer to produce detailed pictures or organs, soft tissues, bone, and virtually all other internal body structures. Does ont use ionizing radiation.
What does MRI examin
Useful for soft tissue (muscle, ligament, cartilage, spinal cord, and marrow spaces)
Ultrasound
No exposure to radiation. Allows “real time” structure and movement of organs
X-ray signs of child abuse
Multiple rib fractures, multiple fractures in multiple stages of healing, femur fracture. You are a mandated reporter of suspected abuse.
Commonly missed fractures
Ribs, navicular schaphoid (law suit bone - Snuff box), and tarsal/metatarsal
Follow up of fractures
Repeat x-ray in 6 weeks to 2 months to determine healing
Referrals of children with fractures
Indicated for fractures that extend through the growth plate
Treatment of open fractures
Warrant aggressive treatment and referral
Education for patients regarding fractures
Immediately report intense pain, hypoesthesia, paresthesia, muscle weakness or paralysis (compartment syndrome); they need immediate referral
What to educate patients about healing fractures
Previously fractured and healed bones are more prone to refracture. Encourage good physical conditioning and consistent exercise to strengthen muscles. Work and play safely
Does a negative x-ray exclude a fracture?
No! Some fractures take days to show up
Splinting possible fractures
Splint to protect injured limb, and explain to the patient that they need to report pain that increases or does not resolve
System for evaluation of chest x-ray
Check for symmetry. Structures - bone: ribs, clavicle, spaculae - Soft tissues: neck, sides of chest wall, breasts. Diaphragm. Heart. Lungs
Evaluation of the diaphragm on chest x-ray
Note clarity, shape, and position. Should be rounded or dome-like. Note sharpness of costophrenic angles.
Blunting of costophrenic angles of diaphragm on chest x-ray
Effusion of at least 200 ml or pleural scarring
Unilateral evaluation of diaphragm on chest x-ray
Pralysis of phrenic nerve
Evaluation of heart on chest x-ray
Size should be 1/2 distance of chest area. If enlarged, differential diagnoses should include cardiomegalyo r pericardial effusion.
Boot shapred heart on PA view of chest x-ray
Indicates left ventricular enlargement
Loss of normal heart borders on chest x-ray
Indicates enlargement of R & L atria or R ventricle
Evaluation of lungs on chest x-ray
Remember the apices. Usually not visible throughout except for blood vessels. Look for infiltrates (white areas), masses or unilateral white out. Know location of different lobes on x-ray
Ordering the abdominal x-ray
Use only for specific purposes: intestinal obstruction, perforated viscus, ingested foreign body.
Abdominal series includes what positions
Supine abdomen AP, upright abdomen AP, and one chest-ray
System for evaluation of abdominal x-ray
Bones, soft tissues, LUQ, RUQ, lower mid-abdomen, pelvis, gut - small bowel and large bowel
Air or abnormal gas collection on abnormal abdominal x-ray
Perforated viscus, necrotizing entercolitis, post-op, peritoneal dialysis
Water on abnormal abdominal x-ray
Ascites, bowel obstruction (air/fluid levels)
Bone on abnormal abdominal x-ray
Spinal abnormalities or rib fractures
Abnormal bowel patterns of abdominal x-ray
Dilated loops or displacement
Ordering the x-ray for evaluation of trauma to an extremity
Know the mechanism of injury. Physical exam is crucial. Views are usually 2-3 different agnles. Comparison views in children - to do or not to do. Give radiologist precise clinical information.
Reading the x-ray of an extremity
Use bright light liberally. You have the advantage. Evaluate for periosteum
Peristeum
White line around edge of bone
Method of approach reading extremity x-rays
Identify the bones. Follow the edges of each bone; looking for interruption of periosteum. Do same for all views. Go back to area of interest and repeat.
Fat pad sign
Normally, on a lateral radiograph of the elbow held in 90 degree flexion, lucency that represents fat is present along the anterior surface of the distal humerus, and no lucency is visualized along its posterior surface.
A positive fat pad sign
An elevated anterior lucency and/or a visible posterior lucency on a true radiograph of an elbow flexed at 90 degrees is described as a positive sign.
Salter-Harris fracture
A fracture that involves the epiphyseal plate or growth plate of a bone. Common injury among children, occurring in 15% of childhood long bone fracture.
