These review notes were compiled from class notes (1996 - 97; David Gendreau, DC, DACBR, Victor Tong, DC, DACBR), seminar notes, Dr. Yokum's text books and board review notes. Please
e-mail me with any errors or ommissions. Submissions are also welcome.
X-ray Colors:
- gas = black
- fat = black
- mm, water and soft tissue = gray
- Bone and metal are white
Initial Approach Questions:
- ID the view (motive for film)
- First Impression: normal or abnormal
- Second Impression: Congenital or acquired
- Age and sex of the patient
- Problem with bone?, joint?, soft tissue?
A film can always be interpreted on the following criteria:
- what is the color?
- what is the location?
- what is the shape?
- what is the age?
- what is the sex?
Color Motives:
- normal x-rays the bone is white and the soft tissue gray, gas and fat is black
- bone is white, soft tissue is white = under-penetrated (bad film, or soft tissue film)
- bone is dark, soft tissue dark = over-penetrated (bad film or focus on a spot)
- bone is gray and soft tissue is gray = osteopenia (~ MM, lytic met, hyperparathyroid)
- bone is white and the soft tissue is dark = check bone
- to darken soft tissue, decrease KVP by 15% and double MAS
- to whiten soft tissue, increase KVP by 15% and cut MAS by half
- KVP is like a dimmer switch
Periosteum:
- New growth in response to cortical destruction: 1. Parallel or laminated and 2. Radiating or spiculated (sunburst)
- Parallel: indicates infection or trauma, occurs in long and tubular bones, must see white-dark-white with exceptions of Ewing's Sarcoma
- Radiating/spiculated: seen with primary bone malignancy (sarcoma), spicules arranged at 90 degrees to the bone, can occur on any bone. Think osteosarcoma for 10 - 30 year old patients, think chondro- or fibrosarcoma if patient is > 40 years old. Exception is Multiple myeloma (MM).
- MM does not cause periosteal reaction because it affects the medulla and not the cortex.
- Metastatic Cancer also does not cause periosteal reaction because it goes to high blood flow areas in the medulla.
Cortex:
- thinning: osteoporosis
- thickening: Paget's
- interruption: fx or nonunion
- deformity: softening, bending, twisting, with cortex fairly intact
- blastic met does not affect the joints
Medulla:
- turns whiter or darker,
- whiter = Paget's, blastic met
- darker = lytic met, MM, benign bone tumor
Views:
Cranium:
(nothing at this time)
Cervical spine (C/S): Lateral Cervical Spine (FFD = 72"):
- ADI space: < 3 mm in adults, < 5 mm in children (< 13 yo) (increase of ADI space, think about Down's syndrome, RA, AS, Psoriatic, Reiter's and trauma)
- check the spinolaminar line, C1 vs. C2.
- Check the front of the bodies (syndesmophytes = AS, hyperflowing = DISH, lips and spurring = DJD or infection)
- check the base of the dens for radiolucent lines (fx, os odontoidium, agenesis, mach line)
- Check the dens for height, alignment and color (if dens is above the occiput, ~ basilar invagination, 2 types: Congenital and pathologic, i.e., from Paget's, fibrous dysplasia, and trauma)
- Chamberlains line: hard palate to foramen magnum, < 7 mm of dens below the line = normal
- MacGregor's line: back of the hard palate to bottom of the occiput. Normal is < 8 mm in males, < 10 mm in females
- Martin's Basilar angle: < 152 degrees, between nasion to sella turcica. > 152 degrees = platybasia
- Check the bodies for change of color and shape
- Disc spaces for changes in size and color
- check the arch of the atlas, pedicle of C2
- Check the back of the bodies, pedicles and facets of the remaining vertebra
- Check all spinolaminar lines
- Check the SP's
- Check soft tissue in front of and behind the bodies.
- for dx of infection, should see soft tissue swelling
- check SP's of C6, C7 and T1 for Clay shoveler's fx due to hyperflexion avulsion
Rules for reading APOM: (8 x 10 film, CR through base of the dens, FFD 40")
- Look for the dens
- read from the top down
- R/O mach lines: occiput, teeth, arch of the atlas
- check the base of the dens for lucent line
- trace dens to make sure it's attached and in the right place
- check the paraodontoid spaces
- check the lateral masses of C1 for overhanging
- check the bodies of C2, C3
- check the disc space between C2, C3
- check the arch of C1 and the SP of C2 and C3 for lucency of spina bifida
- Soft tissue calcification around jaw (lymph nodes)
- fx will have jagged and rough edges
Rules for reading APLS: (FFD = 40" with a 15 degree cephalad tube tilt)
- Check T1 and C7 TP
- check bodies for shape and color
- check the disc spaces and the color of the disc spaces
- check for uncinate arthrosis
- check SP's for vertical lucency (C4 have larynx shadow)
- horizontally for fx
- check for tracheal air shadow deviation
- check for soft tissue on either side of the spine (lymph nodes and arteries)
Rules for reading C/S obliques: (15 degree cephalad tube tilt).
- purpose is to view IVF
- mnemonic: COP = cervical opposite posterior
- 1st IVF visible is C2 - C3
- IVF boundaries are: ant. = bodies and uncinates, sup. and inf. = pedicles above and below, post. = facets.
- hour glass impingement of the IVF is from uncinate and facet arthrosis
- enlarged IVF may be due to neurofibroma (scalloping of posterior bodies, possible café au lait spots) or from agenisis of the pedicle. Fibrous Dysplasia has rough or jagged border, KA "Coast of Maine", Neurofibroma is called "Coast of California".
- Anterior oblique: Same side vertebral structures (IVF, pedicles). Marker behind the spine.
- Posterior oblique: Opposite IVF/pedicle. Marker in front of the spine.
Thoracic spine (T/S):
- motive is scout
- be careful to compare color to surrounding soft tissue
- compression fx needs a 25% loss of body height to make dx.
- check all vertebral body heights on the posterior aspect, pathologic fx will cause decrease in posterior body height, osteoporosis won't.
- any fx that is not considered traumatic is considered pathologic until proven otherwise.
- osteoporosis is due to the decrease in that amount of anabolic hormones, i.e., estrogen, testosterone, progesterone
Lumbar spine (L/S):
Views
- Anterior Oblique: Opposite Scotty Dog, same side SIJ. Marker behind the spine
- Posterior Oblique: Same Scotty, opposite SIJ. Marker in front of the spine.
- Lateral: Collapse of the vertebral body suggests malignant infiltration or osteoporosis (if the disc space is obliterated then infection is more likely. Scalloping of the posterior vertebral body suggests long term intradural lesion. Expansion of the IVF suggests neurofibroma. Osteophytic narrowing of the IVF suggest possible root compression (often asymptomatic). Narrow disc space, narrow canal and hypertrophic facet joints suggest IVD disease or spinal stenosis. (3, p. 379)
Rules for reading AP L/S:
- check the lower 1/3 of the SIJ (the synovial part)
- compare the color and shape of the ilia and check Riser's sign (age)
- look across the iliac crest for L4 SP.
- count to the 12th rib
- count down from the 12th rib looking for lumbarization and sacralization
- check the sacrum for changes in color, shape, spina bifida
- check for L5-S1 tropism
- "square block heads" all the way up (bodies, pedicles, TP's and SP's).
- check for aortic aneurysm between L2 -L4
- renal artery problems ~ L2
- compare soft tissue on each side between the ribs and the iliac crest
- check the soft tissue of the pelvic inlet