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DIAGNOSTIC IMAGING 1 – 1/08/08

Osteopenia: Low Bone Density. Osteopenia is a decrease in bone or low bone density. In this condition, 1/3 to ½ of the normal bone density can be gone. There can be nutritional reasons, hormonal reasons or bone disease (tumor) causing low bone density.

Radiolucent: Ionizing Radiation or X-ray is allowed through. The most radiolucent material in the human body is gas/air. Air is found in the lungs and in the GI. Second most radiolucent is fat – water (soft tissue) – bone (a. medullary/trabecular b. cortex) – metal.

Most Radiolucent ---------- Least Radiolucent

1. Air/Gas

2. Fat

3. Water/Soft Tissue

4. Bone

a. Medullary/Trabecular Bone

b. Cortex

5. Metal

Contrast (Image): # of Shades of Black and White. The highest contrast has 2 shades of gray (also known as -- white and black). In the lung fields, we benefit from many shades of gray.

A). Bone film = we like high contrast (black and white only).

B). In a chest film/GI film = we benefit from lower contrast.

A gray bone film may indicate too much kVp. kVp is the controller of contrast. More kVP equals more shades of gray. Less kVP equals less shades of gray (better contrast).

Oral Contrast: Barium swallow. The patient swallows barium to allow visualization of irregularities.

Contrast agents allow us to tell anatomical structures better. We can put contrast agents in sinuses, GI, or rectum. We can also do a barium enema studies for the distal colon and ileum.

Example of Other Contrast Studies

Arteriogram, Venogram, Spinal Canal Myelogram (Inside the Dural Sleeve to show us the inner lining of the thecal sac to check if something is pushing on it), Intravenous Pyelogram, Air Bronchogram

In nuclear medicine, the patient becomes the emitter of radiation. This is different than a contrast study.

Differential Absorption: Most dense structure in the body is cortical bone. In differential absorption, some tissues absorb more X-rays than other tissues. This helps to give different visualizations. We use this concept to identify anatomy on radiographic images.

Metastasis: Spreading…Ex.—Cancer spreading or Infection Spreading. The term actually refers to the general spreading of disease, but is used most often in the context of cancer.

Hounsfield Units: Units used for a CT scan. CT’s use pixels and voxels. The voxel gets assigned a single Hounsfield Value.

Hematopoeisis: Blood Production…Blood production occurs in the marrow. As you age, marrow decreases in production. Red marrow converts to yellow marrow. Yellow marrow produces less blood. Disease of ends of long bones or spine in your later years will produce anemias. Normocytic/normochromic anemia can occur if too much of the blood producing capability is lost. The blood cells are the normal size and color, but there are fewer of them, hence the normocytic & normochromic anemia. Children produce lots of blood cells because they have lots of red marrow. Children need to have the capacity to meet the ever expanding volume of growth; whereas, adults do not possess this capacity.

Attenuating Technology: Plain film, CT scan, and tomograms are examples. Cortical bone absorbs more than trabecular bone. Cortical bone appears a different color than trabecular bone based on attenuation.

Tomography: A picture of layers of a patient using thin sections. The film and tube are used with a pivot point to get an arc of movement. Items not used or visualized in a tomogram are blurred. Later, a computer was added to produce CT.

Emission Technology: Looks at objects in the body emitting energy.

A). MRI = looks at what comes out of the body from the patient. The emission is in the FM frequency. We put energy in, stop, and then check the emission of energy in an MRI study.

B). Bone Scan = Another source of emission is a bone scan. A bone scan typically used technicium 99 linked to phosphate which helps as a carrier to get into bone. Photons are emitted from the patient and are measured. We map where the emissions are coming from. The only way disease is highlighted on a scan is due to exaggerated osteoblastic activity. The bone scan will produce a dark spot, called a hot spot. This indicates a disease that produces osteoblastic activity. Dead/dying areas will not produce a hot spot (ex.—multiple myeloma). Bone infections, bone tumor metastasis may indicate a hot spot due to osteoblastic activity.

The information comes from the patient and what they emit from them. An MRI emits protons. Radionucleotide studies (SPECT, PET, and Bone Scan) emit photons.

DIAGNOSTIC IMAGING – 1/09/08

Where does imaging fit in the chiropractic practice?

Identify the Chief complaint – History of the Chief Complaint – OPPQRST

Review of System

Examination: Appropriate level of Physical Diagnosis, Orthopedic, Neurological & Chiropractic Exams. The appropriate level of exam is based on gender & age. Consider the circumstances of the patient when performing the exam.

Assemble the collected information into the Differential Diagnosis: Only at this point by assembling the data do we have a chance to make a differential diagnosis. A differential diagnosis relates to probabilities. We put emphasis on the top 3 differential diagnosis. Treatment works better when we consider probabilities and not possibilities.

Decide what, if any, further studies are required to limit the Differential considerations: Rule-in, Rule-out, and Monitor known conditions…Frame your questions by ruling-in rather than ruling-out.

History and Physical Exam are the most important aspects of these cases. Differential accuracy depends on these findings.

There are some conditions that present the same way on X-ray, but are different conditions. These are called twin pairs…Weight of the Evidence can become important (which parts of the evidence carry the most weight).

Review of findings with the patient: If the patient accepts care, sign appropriate paperwork and begin care. You as a doctor must determine if you can help them. If you can’t help them, it is perfectly OK to refer them to another party that can.

Patients ask a couple questions: What do I have? Can you help me? What are you going to do to me? How much is it going to cost me?

Don’t offer therapy to a patient, if you don’t think you can help them or if they don’t fit your treatment profile (based on personality, person or condition).

DIAGNOSTIC IMAGING – 1/15/08

*** Get Started learning normal X-ray anatomy ***

*** All Roentgenometrics are available for testing ***

NORMAL X-RAY ANATOMY

Basic Rules for Interpretation

Plain films are a 2 dimensional gray scale image of a 3 dimensional anatomical structure

Four Basic Densities: 1). Metal (very bright white) 2). Bone 3). Fat/Soft Tissue 4). Water (least white)

Anterior Posterior Open Mouth

Open-mouth radiograph of the cervical spine. On this radiograph, the odontoid process, the body of C2 and lateral masses of the atlas are well demonstrated. The Atlantoaxial joints are seen to best advantage possible. (View on overhead slide has atlantooccipital joint – lateral masses of C1 – odontoid process – C2 – atlantoaxial joint).

AP Lower Cervical View

Note that the projection demonstrates the C3-C7 vertebral bodies and the intervertebral spaces. The spinous processes are seen superimposed on the bodies resembling tear drops. The C1 and C2 vertebrae are not adequately seen. (Picture on slide depicts – occipital bone, lateral masses, uncinate processes, intervertebral disk spaces, spinous processes). The uncinate processes are unique to this view.

*** For all X-rays…Know which level you are at! Know how to find R vs. L ***

Lateral Cervical

Description on picture on overhead: Anterior arch of atlas – odontoid process – body of C2 – spinous process – intervertebral disk, - apophyseal joints – C7, C6, C5, C4, C3

We can see the facet column on the lateral view, but we have trouble telling L from R

Cervical Oblique

Neural Foramina (IVF’s) – Apophyseal joints – Intervertebral disc space. This view is effective primarily for demonstrating the IVF’s. These views can be done in anterior and/or posterior positions. We need a tube tilt for oblique views in the cervical spine. The tube tilt is 15 degrees either cephalad or caudal depending on the view. A cephalad tube tilt of about 15 degrees when taking a posterior oblique shot. A 15 degree caudal tilt is need for anterior oblique shot.

Shot Closest to Film Tube Tilt IVF’s Visualized Best

Left Post. Oblique Left Shoulder 15 Cephalad Right

Right Post. Oblique Right Shoulder 15 Cephalad Left

Left Ant. Oblique Left 15 Caudal Left

Right Ant. Oblique Right 15 Caudal Right

We need to do 2 obliques because of equipment. Some influencing factors include table and size of room (ceiling).

At the oblique position, check the pedicle and the cortical profile.

Note: A left posterior oblique and right anterior oblique view would give you the same view. The same is true for a Right Posterior Oblique and Left. Anterior Oblique films.

In oblique views, you often cannot see the spinous process.

Posterior-Anterior Chest

Not good for rib counting. Cardiac silhouette is over to the left. You can use the cardiac silhouette to determine L from R. You can also use the gas density bubble (meganblaz – fundal gas bubble or stomach gas), which should be over to the left. Another item to aid in identification is the splenic flexure gas bubble (gas bubble of the spleen below the diaphragm) to the left.

The right side should be gas-less. There shouldn’t be a bubble below the R hemi-diaphragm due to the liver. The liver is a solid organ.

Determination of L vs. R on a PA Chest

1. Cardiac Silhouette: It should be on the Left side

2. Meganblaz/Fundal Gas Bubble: Should be on the Left side

3. Splenic Flexure & Splenic Gas Bubble: Should be on the Left side

4. No gas bubble on the R side due to the Liver

Rib Determination

1. Find C7…C7 TP’s are horizontal or point down.

2. Find T1…T1 has TP’s that are straight up.

3. Using this info determine the # for the ribs working from T1 going down.

Lumbar Spine Obliques

In lumbar spine obliques, you want to include the sacrum and T12. Remember that the female pelvis is shorter vertically and wider vs. the male which is longer vertically and narrow. Identify the ilium that lies most flat to assist with identification.

Scotty Dog

Neck of the Scotty dog = the pars interarticularis (parts between the joints).

Reasons for Lumbar Obliques

We take lumbar obliques for different reasons. The lateral lumbar views give the IVF’s. Lumbar obliques give us the posterior elements 1 side at a time. Both facets are present on a lateral view. This can present problems. Taking an oblique picture may help to give us a better visualization of 1 side and 1 facet (ex.—L4 Left facet)

Ex.—RAO Lumbar – The right crest is closest to the film. The left is closer to the tube. The left crest is more parallel. We visualize the left side better.

*** Know the roentgenometrics and know the X-ray anatomy ***

Percentage Method to Determine Slippage

Process to Determine Slippage

1. Draw a line from front to back of the sacrum or vertebral level.

2. Draw a line tangential to the sacral base line or the body of the lower vertebra.

3. Measure the two distances to determine the amount slippage.

4. Use the percentage method dividing the slippage amount by the length of the base amount (sacrum or vertebra can be used as the base) to determine the amount/percentage of slippage.

Ex. Red-line = 50 mm

Red line to black line = 5 mm

5/50 x 100 = 10%

This method helps to quantify the anterior slippage of one vertebra over another. 7% of the people have anterior slippage. There are stable and unstable cases of anterior slippage. The most reliable way for plain film visualization is the compression-distraction view. Draw the lines for a quick calculation of how far forward the vertebra travels.

Myerding Method

Grades the slippage (1-5) based on dividing up the sacrum in fifths. Slippage of the vertebra to that number on the sacrum by the vertebra touching/bisecting the indicated number determines the overall amount of slippage. This method is not as good as the percentage method because the person can get worse in the percentage method (10- 20%) vs. the person can get worse with the Myerding method and still be the same classification (ex. Class 2 at 10% and Class 2 at 20%). In this situation, the objective measure of slippage does not appear as significant as does the percentage method. This could impact treatment and prognosis.

DIAGNOSTIC IMAGING – 1/16/08

Roentgenometrics

Klein’s Line

Connect the dots and extend the line across the femur head. ¼ to 1/3 of the femur head should be in front of the line. Avascular necrosis will make the line and measurement abnormal. The femur head is closed due to mechanical loads placed on healthy tissue/bone. Dead bone has compromised blood supply and cannot bear the mechanical stress. The inability to bear mechanical loads can cause fracture of the femoral head and a break in Klein’s Line...Another cause of a break of Klein’s line would be femur neck fracture due to trauma.

Ex.—Paget’s Disease: Produces Bone Softening…Violates Klein’s line and may cause Acetabular Violation

Quality Control

There will always be some level of work-up prior to an X-ray.

Ex.—A skateboarding accident…You initially think fracture, but you also suspect arterial or nervous involvement. You don’t’ X-ray them first. You would check sensation, strength, reflex, opposition, and capillary refill first. If they are deficient, send them to the emergency room!

BB Fracture: Both Bones (radius and ulna)

Quality Control

Why is it important? -- We radiograph for probabilities. Quality control and good radiographs are important to have for many reasons:

Reasons to X-ray (Not an Inclusive List)

1. Differentials diagnosis 2. To check to see if what we are looking for is there 3. Not to miss anything 4. To send out (professional images) 5. To have good films for the patient to look at 6. Provide defensive chiropractic/medicine 7. Provide the opportunity to find occult pathology 8. Quality control can save our patients radiation dose and retakes 8. Quality control will help will state and insurance company to fulfill their requirements

Looking at the film is the best way to check the film and the best way to provide quality control

“82 things have to go right to make a good film. There are fewer things to go right to make a good digital image.”

What are the roadblocks to Quality images? 1. Cost/Money 2. Time 3.Training 4. Equipment 5. Facilities 6. Human Error 7. Room Set Up 8. Not adjusting your technique to the person or situation (osteoporosis, age, gender, bone density, correction factor, etc.),

How can we achieve high quality? A, B, C (Use the ABC’s for your technical and professional review)

ABC’s of Quality Control

A = Anatomy…Is the entire region depicted on the radiograph…Ex.–We need to count vertebra by vertebra. Make sure the proper amount of vertebra, pedicles, lamina and TP’s are present

B = Bone…Search for signs of patient motion and evaluate technique. You want the right balance for kVP and mAs without patient motion. You may also want to decrease the time to limit motion….Cortical and/or trabecular destruction or pathology must be checked. Everything with a cortex needs to be looked at. Scan your finger on the film to look at the cortex. Localized lucency is often found with part of the vertebra/bone missing. The lucency may be due to tumor eating away at the cortex or motion. If the lucency is at one, level tumor is probable vs. if the lucency appears at multiple levels, motion would be present.

C = Cartilage…Reminds us to look into the various joint spaces which may become obscured by positioning errors. If you can’t see the joint spaces, you expect to see, you must make a change. Also search for signs of arthritis, injury, and anomaly

S = Soft tissues - Target approach to the regional inspection of the presented soft tissues. Helps evaluate technique and signs of injury or pathology. Ex.—Lumbar spine, you must be able to see the edge of the psoas to find a possible AAA.

If you find a bad film, retake it. Retakes are much cheaper than missing something or getting sued.

DIAGNOSTIC IMAGING – 1/22/08

DIAGNOSTIC IMPERATIVES IN RADIOLOGY

Sectional vs. Full Spine X-rays

Radiographs are usually only taken of the area involved, unless there is significant clinical indication to warrant full spine exposure. Imaging is for documentation not education.

Full spine X-rays are warranted for scoliosis due to possible progression of scoliosis. In older patients, it may be necessary to do sectional studies for scoliosis in addition to full spine exposures. The full spine allows us to look at the entire kinetic chain to show posture that may present additional pathology. The sectional film typically shows pathology better.

In a perfect world these two items would not be mutually exclusive. However, we are required to deal with realities of cost versus benefit. …Radiographs should be taken for clinical reasons and not for patient education.

3 reasons to X-ray

1. Rule In 2. Rule Out 3. Monitor Status…There is a 4th reason for X-ray. This reason occurs only in an educational institution (4. Education/Research)

Importance of Billing

Improper use of our billing cods or failure to properly document the necessity for certain radiologic procedures impedes accurate reimbursement. The behavior could be considered fraudulent. Improper billing codes may shut the doors towards proper patient care.

Importance of a Minimum of 2 Views

A minimum of two views, at right angles to each other, must be taken for adequate initial diagnostic interpretation. A single axis radiographic study is typically denied re-imbursement as a non-diagnostic study.

Ex.—There at times when we have determined that additional views are necessary to complete a diagnostic series. A cervical spine series may have more than two views (ex. – 3 view cervical spine series).

Ex. – PA Chest – If something is found…We can then take additional views after that. We would still be OK for diagnosis with the PA chest and for reimbursement.

Decisions concerning the use of diagnostic imaging should not be based on reimbursement, but rather clinical indication. (Base your reasoning on your clinical diagnosis and differentials).

Summary of Diagnostic Imperatives in Radiology

Important Reasons for X-ray

1. Rule IN, Rule OUT

2. MONITOR a known condition

3. Based on Clinical Need

Liability Issues in Diagnostic Imaging

A chiropractor can choose who performs the study, who interprets the study, and who generates a written report of the study. The professional component of an imaging study (report generations) must be performed. The choices above affect the level of liability.

While checklists are sometimes used in recording radiographic findings it is not appropriate for the professional interpretation. The very nature of the checklist insures that the results will be incomplete with regard to the broad range of radiographic findings.

Study results become integrated into the patient record and impact management. Chiropractors who used radiologists have benefited from enhanced diagnostic accuracy. This reduces the rate of false positive and false negative findings. This allows more time to consistently and competently deliver required care.

Who is involved in providing radiology services?

Radiology Tech = The Radiologic technologist or radiographer, is the person, other than a license practitioner, who, with supervision or certification, may apply radiography at humans for diagnostic purposes. This individual does not practice independently but performs studies by referral or the direction of a licensed practitioner. The tech performs all studies under the license of the physician. This is called vicarious liability.

General Practitioner = The general practitioner is a healthcare practitioner licensed to practice within their scope of practice. Decisions regarding if and when patients require radiographic studies is left to this individual.

Radiologist = The radiologist is a licensed practitioner certified by a recognized national certification board in the specialty of radiology. Radiologists may supervise and interpret routine radiologic exams and advances imaging procedures.

Services in Radiology

The technical component: The portion of radiology services that includes providing the facilities, equipment, resources, personnel, supplies and support needed to perform and produce the diagnostic study.

Professional Component: This represents the participation and services provided by a licensed radiologist who performs the diagnostic interpretation of each study. It is required to document the diagnostic conclusions of the study by a written and signed radiology report.

Technical Component and Professional Component are the two components for the total bill. The ratio was 2:1 (technical: professional). This ratio has changed over the years.

Second Opinion or Consultation: This service is requested in unusual circumstances when a practitioner or radiologist feels more input in the case is needed in the best interest of the patient. The second opinion is appropriate only after production of the study and generation of a written report.

Interpretation and reporting of diagnostic studies

The standard of care is that all radiographic studies are performed to reach a diagnostic conclusion. Formal interpretation and reporting of each imaging study documents the findings. A written, usually typed, interpretation of the study is included as a part of the permanent record. These reports are signed by the radiologist performing the interpretation. The chiropractor, as a portal of entry provider, chooses who is to perform the interpretation of the imaging studies and generate the written report. The professional component of imaging study must be performed and can be done by a general practitioner; however, the general practitioner then inherits the specialist’s liability.

Note: Many of insurance companies only reimburse the radiologist for these services.

The level of responsibility in malpractice in the field of radiology is best judged as a reflection of current standards of care. Individuals or institutions are held responsible based on the types, and level of service they provide.

LEVELS OF LIABILITY

Ex. – Writing of the report can be from the chiropractor who took the films or a radiologist contracted, by you to read the films and generate the report. There could also be a hybrid of both the radiologist and chiropractor read the films based on film (what’s on them), level of difficulty, and other characteristics. The radiologist always has specialist liability. The chiropractor in reading and interpreting the film assumes liability of a specialist. If the chiropractor does not send a film, there will be specialist liability for the chiropractor. If you send all the films, the chiropractor assumes generalist/general practitioner levels. The question is ,would a reasonable and competent chiropractor be able to determine what is on the film? For a specialist, would a reasonable and competent specialist/radiologist be able to determine what is on the film?

3 CHOICES

1. Send None (no films sent) – Specialist Liability for the GP

2. Send All Films (all films sent) – Generalist Liability for the GP

3. Pick and choose to send Films (some films sent) – Specialist Liability for the GP

We only have 2 levels of liability: 1). General Practice (reinforced by sending all films to radiologist) 2). Specialist: If you send none or pick and choose to send films you assume some of the specialist liability. The courts have decided that picking and choosing the sending of films, you assume the liability of a specialist, because the specialist is the expert to determine what should be sent out and not be sent out.

Models of Payment

1. You take films – You can submit for reimbursement for taking film and send a check for the radiologist to read them.

2. You take the films – You can submit for reimbursement for taking the films and send the info for the radiologist to submit for their own reimbursement.

3. You take the films - You can bill the patient directly and ask the patient to submit the info/bill to seek their own reimbursement.

Issues of Liability

There are only 3 behaviors possible in the diagnostic imaging area

Refers all-GP liability

Refers none – Specialist liability

Refers some – specialist liability

Accuracy

The study was taken around the country in a similarly lit room, with standard distances, with fixed screen sizes and many other similarities with fixed # of cases to identify, read and diagnose. .

The results indicated best results for chiropractic radiologists.

Best Accuracy ---- Worst

Chiro Radiologists (71%) – Sk. Radiologists and Fellows (70.18%) – Chiropractic Radiology Residents (61.54) – General Medical Radiologists (51.64) – Medical Radiology Residents (44.64) – Medical Clinicians (31.26) – Chiropractic Clinicians (28.38) – Chiropractic Students (20.45) – Medical Students (5.74)

No statistical significance between Medical GP’s and Chiropractic GP’s on accuracy. We have better results as chiropractic students than medical students. There may be better cooperation in the medical model as their radiologists get better in time (greater progress).

DIAGNOSTIC IMAGING – 1/23/08

RADIOLOGY REPORT – What is the role of the report?

Verbal rendition of the film study

Medicolegal communication

Insurance Company

Workman’s Compensation boards

Attorneys

Provides a standard for comparison

Part of the permanent patient record

May replace the lost film

Professional Communication

Expedite treatment by highlighting indications and contraindications for treatment

The report can be submitted for the bill. The report is a legal document used to explain the x-rays, diagnose, establish treatment protocols and can be used for reimbursement. Try not to store the report in the same folder as the films. Copy the report and place the copy in the X-ray folder, while putting the report elsewhere (like in the patient folder).

Ex. --If the patient has an AAA over 4 cm, a consultation with a vascular surgeon must take place.

Report Format

1. Stationary -- We need to know who did the work, name of company, billing address, contact numbers. The business pertinent information of the person performing the document

2. Patient Information – Who the patient is (name or ID number should be given). Age at time of study or birthdate should be placed on the report.

3. Radiology Information -- Date of the exam, what films were taken/views (ex. 5 view with flexion and extension, or was there a swimmer’s view in the series)?

4. Technique-optional – This information is required for a CT study, but optional on a plain film study.

5. Body (Findings) – Descriptive language is used to convert the picture to meaningful words. This is usually the longest section of the report.

6. Impressions (Conclusion) – Ex. Facet Arthrosis, L Knee DJD – This is your best guess. This is where the physician focuses their attention. Often, the physician looks at this section first.

7. Recommendations (when needed) – Often the radiologist, doesn’t like recommendations unless they need to. This way when the recommendation is made, it stands out. When a recommendation needs to be said, it should go in this section (ex. – lytic metastasis to a bone – a recommendation should be made)

Radiologists agree as to the content of the report, but it is up to the radiologist to determine the format. Format but not content differ in diagnostic report.

DIAGNOSTIC IMAGING – 1/29/08

Imaging Tools

Plain Film: We are starting to go with digital X-rays…The tool is the same with sensitivity (incidence of true +) and specificity (incidence of true -)

Myelography: We don’t see this too often in the US

CT

Helical CT: Better for use than regular CT

MRI: Expensive imaging tool and have to factor cost-benefit ratio

SPECT: radionucleotide images using emission technology with the patient emitting energy (emitting imaging also includes bone scan)

PET scan: A different radionucleotide study…This first came on the market to scan brains, linked with glucose (brain takes up glucose)

Xe-CT: Not too well used, but this technology is developing.

FMRI: functional MRI…This is developing technology

Plain Film

Solarization: Artifacts of photography

X-ray physics started with Roentgen…We have a 3 dimensional objects projected on 2 dimensions

Panorex View: A single sheet of film was taken in a cassette and was curved. Many dentists have this technology. Once this was the premiere technology for visualizing upper cervical and cranio-facial trauma. Anatomy was visualized y spreading the image over the film and by moving the tube over the anatomy laying out the view. This is the first time we could lay out craniofacial structures. This was expensive. CT came along and there was no market for panorex views. Panorex was pushed out of the emergency room imaging suites. Panorex was then sold to dentists.

Plan Film Strengths

Availability

Relatively Low Cost

Well Know Usages

1. Entry Level Diagnostic Tool = Plain film is a good place to start as an entry level diagnostic tool.

2. Search for contraindications to further imaging: Ex.—patient cannot use MRI due to shrapnel, so X-ray would be a good entry level study and way to search for contraindications

3. Quick Assessment of Gross Osseous structures and soft tissue integrity

Plain film can be used as inclusion criteria. Ex. ---No fracture revealed on plain film…This allows for the possible later inclusion based on other clinical evidence and other imaging. There is a conflict between the test result and the patient presentation. In this case, we would base our clinical judgment on the patient presentation. There is less risk in doing so.

Plain Film Weaknesses

Ionizing Radiation

Relatively Poor Resolution: We don’t always solve the problem (make the correct diagnosis) – poor resolution.

Poor Spatial Localization: Bad 3-D imaging tool

Soft Tissues Generally Not Seen: Soft tissues not seen like MRI…MRI is the tool for soft tissue, but it is much more expensive (can be 10x more expensive)

Frequently fail to document fractures, even under ideal conditions

Digital vs. Standard X-ray

The Digital imaging per image gives the patient more radiation, but there is less radiation overall due to decreased chances for repeats. Shot for shot, digital imaging is slower (more chance for exposure) than regular plain film.

Line Pairs and Resolution

Plain film has a better line pairs per unit than other forms of imaging. From a detail-image point of view, X-ray is best. Plain film has up to 10 line pairs per mm. 1-3 line pairs per mm are what CT and MRI can have.

Plain Film May be Limited By:

Poor Patient Positioning

Patient Motion

Incomplete Series

Trauma Patients, the elderly may not be able to cooperate during the exam:

C1-C2 region tough to evaluate: We have to play with head and teeth position and need increased kVP to get through the skull

C6-C7 region also tough to evaluate: We had to invent a view to see this image (Swimmer’s)

Plain film Proper Use

Introductory Study

Can Evaluate IVF’s well

Use to rule out contraindications for Advanced Imaging

Not good for Central Canal Stenosis: Measurements for central canal stenosis don’t work…Use MRI or CT…Room for the cord becomes the important issue

Tomography

The next generation of film beyond plain film and panorex.

“Tomo”: Tomo means slice or layering…Tomography = study of layered images

Types: Linear, Circular, Elliptical, Hypocycloidal, Trispiral

Tomogram = the tube and film are moved together. The movement creates a pivot point. The pivot point becomes the focus of the layer of that image. In original tomograms, the edges were blurred but the center was clear. The anatomy at the point of pivot then shows up on the film. Tomography was relieved upon till CT came along.

Myelography

Air was the 1st contrast agent used

Other materials include poppy seed oil, pantopaque

In the 1940’s water soluble products (very toxic)…Incidence of 40% arachnoiditis with water

1970 metrizamide non-ionic, water soluble, in use today

Headache is the most common complaint from myelograms. There can be temporary increase in pressure from the air bubbles and contrast agents. Poppy seed oil and pantopaque were used because they are lipid soluble. They are very tough to get out of the system. The poppy seed oil and pantopaque can remain in the system for many years because they need to be pulled out of the system. You may get CSF pulled out with pantopaque and poppy seed oil. This caused a low pressure headache, which was slightly worse than the air bubble headache.

*** Know what the best test for the midterm and final based on the case presentation….Ex.—Know which study to order ***

Myelogram relies on a contrast agent. In the 1940’s they wanted a product taken away by body (water soluble). They wanted the product taken away by the kidneys. Arachnoiditis is an inflammatory response that can cause a fibrous mass joining the cauda equinae together. Dural stretch tests, movements in certain positions and others were very painful.

Metrizamide was a better product but still has a complication rate of 10%. This is still lower than the 40-50% of water compounds. All of the myelogram compounds can cause risk to the cord, but each causes its own varying degrees of problems.

Process of Myelogram: The needle enters the thecal sac and provides a bolus of contrast dye. The patient lies on their stomach during the injection. The dye is injected and the doctor moves the table position to change the orientation of the dye in the body

Complications of Myelogram

Arachnoiditis

Infections: By nature of an injection, we can provide an area of infection

Arterial Bleeding: The edge has surgical qualities. We can slice through vessels on the way in. The arterial system is a higher pressure system and can bleed.

Headache: The most common complication. This can be up to 80% of the patients who have myelography performed. The most likely explanation for the headache is the puncturing of the dural sleeve. There can also be sclerotogenous pain from the puncturing of the skin and tissue. The dural sleeve is very highly innervated. The headache can last from minutes up to two weeks.

Image Production of Myelography

Utilizes ionizing radiation

Depends on displacement of contrast column

Differential absorption

The only people we generally deny this imaging tool to is post-therapeutic radiation patients. We can also deny pregnant women and very young children.

The movement of fluid and the displacement of contrast provide the clinical information necessary. The contrast agent is a radio absorbing material.

Proper Use of Myelography

If CT or MR are not available

Patient who cannot undergo MRI because of time, size, claustrophobia, other contraindications

Maybe used in conjunction with CT

CT-Myelograms are currently being linked together. The most sensitive study for herniated nucleus pulposus is a CT-Myelogram. The material is injected first with the myelogram performed (limited). The patient is then shipped to the CT scan suite to perform this study. We now have CT-Myelogram suites. A limited myelogram study is performed and then they continue in the same room to have the CT done. Hospitals are competing for this for market advantage. CT-Myelogram can be a “tiebreaker” between 2 conflicting reports of a myelogram and MRI or CT.

Myelogram Strengths

Relatively Good Availability

Good Cost Benefit Ration

Myelogram Weaknesses

Ionizing Radiation

Relatively Poor Resolution: This is for case information and making a diagnosis.

Soft Tissues Not Well Seen

High Rate of False Negatives

Potential Complications from Contrast agent: Can be real and serious complications.

Image detail on myelogram is like plain film = very good. Line pair performance is good, but not as good as plain film.

BONE SCAN

An Emission technology. MRI is also emission technology. Bone Scan is a limited study with a delay between administration of radioactive material and performing the study. This time is for the body to take up the material. Sometimes, the delay can take up to 3 hours.

3 Phases of a Bone Scan

1. Vascular Phase

2. Soft Tissue Phase

3. Bone Phase

If the condition is osteomyelitis (bone infection), we watch the vascular phase (the vascular distribution of material). We later watch the soft tissue phase (uptake into soft tissues). Osteomyelitis involves multiple parts. We then have another delay (couple hours) as we wait for the bone phase. We look for exaggerated osteoblastic activity.

2 Tools help us look at physiology: 1). Bone Scan (bone physiology) 2). MRI (broader range studied)

Gamma Camera

The camera that catches the emissions from the body.

Bone Scan can show hot spots (radioactive areas). Hot spots are areas of dye intake. In bone scan we use, technicium 99 attached to phosphate. Phosphate is important for bone development and serves to drag the material into the bone.

Correlation to Physical Exam

Always correlate the scan to the clinical findings based on history, physical exam, etc.

Bone scans are cheap and sensitive scans. A hot spot is an area of osteoblastic activity. It could be due to fracture healing, stress fracture/reaction, bone cancer, etc. That is why you should correlate the finding of hot spot to the patient.

Radionucleotide Family

Bone Scan: Most limited of the family. The whole body gets the material. The whole body gets the dose. In infectious conditions, we should view all phases (vascular, bone, etc.).

SPECT

A single photon image, but we use CT. Single Photon Emitted Computer Tomography uses 3 systems to capture the image. This helps to “triangulate” the signal. The 3 receivers are around the patient with the doctor checking specific areas of the body and the computer generating layers. SPECT is more useful than bone scan. Spondylolysis can present as a bone stress fracture. If we can catch this condition by a SPECT, we can brace early and get good history. Small bone defects and trauma may be best checked with SPECT over bone scan.

COMPUTER TOMOGRAPHY - CT

Ionizing Radiation: Radiation is passed through the body. The patient is in between tube and film.

Image based on absorption differentials....Ex.—Air vs. Bone vs. Metal

Computer Generated Pictures: We need the computer to do the calculations to report a Hounsfield value for each pixel or voxel

Hounsfield Unit

Pixels: # pixels determine detail…more pixels more detail. We want small pixels with great #’s for great detail. The # pixels we see is controlled by the manufacturer

Voxels: A volume of tissue that we image. The doctor controls the amount of voxels (by order). Voxel is a choice.

Volume Averaging

Slice Thickness Scout Films

We still have an X-ray tube/generator. The beam passes through the patient. The wires are hooked to sensors that send info to the computer. The fan shaped beam stimulates the detectors…It is hooked to a computer, that produces the image.

DX IMAGING – 2/5/08

Computer Tomography (CT)

Pixels – The Detail of a system is based on the pixel # and controlled by the manufacturer.

Voxel – Can be controlled by the practitioner. There are times thin sections are better and there are times the thick sections are better. Thin sections have less trouble by volume averaging. We can have trouble with the odontoid base fracture because it is an axial fracture, even with a thin slice. We usually have standard protocols to designate our studies. Pars fractures are seen with thin slices. You can request a thin section at the involved section for a pars fracture (ex. – thick slices from L5-L3 and thin slices at L2 for a suspected L2 pars fracture).

Frequency of acute neurological insult can be viewed by MRI. MRI is much more detailed and can give an overview of physiology; however, the equipment available to keep a person alive with severe trauma during an acute situation doesn’t necessitate the use of MRI because the scan takes too long. CT is used due to the ease and efficiency in trauma conditions. Ex – A person with a stroke on a respirator cannot be placed on an MRI, but they can be put through a CT scan. MRI would be the best modality, but the best choice for the patient at the time of a stroke would be the CT scan.

Computer Tomography Strengths

Widely Available

Improved Visualization of Soft Tissues

Can Provide 3 Dimensional Imaging

Accurately Measure a Variety of Structures

Image Manipulation Possible: Feature that is true of 3D image of CT, but it is not the same as MRI. MRI’s cannot manipulate the image as much.

May be combined with myelography

Chest CT

Suspected nodules in the chest is a quick, efficient way to image these nodules and check for calcification. Calcification implies chronicity vs. soft tissue mass which can imply cancer.

CT has made some Measurements Inaccurate

Some measurement lines on X-ray were proven inaccurate once CT scan came of age. This is due to the 3D images that could now be developed.

Each protocol for MRI is specific. Ex.—Headache – Differential Dx can be tumor, tension headache, vascular headache, etc. The protocols are different for each

Cost of a CT-Myelogram

Myelogram is most often combined with CT’s. Disc herniations are sensitivity studies (incidence of true + vs. specificity or incidence of true -). When we deal with HNP, CT is sensitive in 88-90% vs. MRI 90-92% and CT myelogram as sensitive for 95%. CT myelograms are very expensive. Their must be a physician introducing a contrast agent, then perform a limited contrast study, then the patient must be shipped to the CT suite and a CT suite should be performed. This also requires 2 studies to be read. There are issues of transferring the patient between 2 suites, cost of running 2 studies, cost of reading 2 studies, cost of the contrast agent, etc. This expense is passed on to the insurance company and the consumer.

Soft Tissue vs. Bone Window

Soft Tissue Window: Cannot determine parts of bone (trabecular vs. cortical)

Bone Window: Can make out different parts of bone.

Weaknesses of CT

Higher Cost

Ionizing Radiation: We will deny a CT in an area where a patient receives therapeutic dose of radiation (ex. For cancer)

Intracranial Artifacts

Artifacts Secondary to metallic Implants

Dose is Consideration

CT Proper Use

Very good Axial Images

Excellent Bone Detail

Some Application in Neurology Work-Up; This can be due to speed more than anything else

Helical CT or Spiral CT

Although MR imaging is fast becoming the dominant modality for cross sectional musculoskeletal imaging, the availability, speed, and versatility of CT continue to make it a mainstay in emergency NMS imaging.

When plain film isn’t enough, CT can often delineate additional findings that lead to the correct diagnosis and triage.

Traditional CT’s take 25-30 minutes vs. the Helical which takes about 5 minutes.

Spiral CT

Spiral CT has a reformatted image which is clearly superior to any other CT out there.

Better imaging and shorter time and better clarity (diagnostic capability) is from a spiral CT.

Helical CT

This modality has several advantages:

1). extremely rapid data acquisition

2). Optimization of contrast delivery

3). Reduced Respiratory Mis-registration

4). Much more sensitive than plain film in Fracture identification

5). Multiplanar reconstruction (MPR) in 2-D and 3-D possible.

Helical CT’s are not much more expensive. The market place won’t allow the cost to be more expensive despite a superior product.

SPECT/PET Scan

These belong in the area of radionucleotide images. Single Photon Emission Computerized Tomography = SPECT..We have a molecule injected into the patient and we receive emission of a photon from the patient. We map it by a computer with 3 sensors to triangulate the source of the image. We can create layers of activity.

Ex.—Spondylolysis – Bone scan can miss this. Even though there is exaggerated uptake of dye in the pars, the image can be hidden because of the body density. SPECT will show this because it can separate the layers better.

PET = Positron Emission Tomography = We use this for brain studies. We often use glucose linked to radioactive molecule. Glucose crosses the blood-brain barrier very easily. Glucose is also consumed as the brain engages in activity. Glucose use in the brain clues us as to real-time brain activity. This is a whole-body dose. We try to limit the patient to 2-3 per lifetime. Different colors represent different levels of uptake. We can look for symmetry, tasking (listening, memory, auditory, retrieval of memory, etc.)

*** Know #’s for Roetgenometrics Quiz well enough to make some interpretation. Know the general range and what would be grossly outside the range ***

MRI – Magnetic Resonance Imaging

Common Problems

Spinal Fracture

Soft Tissue Injury

Skeletal Survey for signs of metastasis: Often a bone scan can be used (it takes 3-5% for it to be apparent)…MRI will show the metastasis ant 1-3% but is more expensive.

Post-Traumatic complications

Peripheral Entrapment

Central Canal Stenosis

Intracranial Abnormalities

A benefit of MRI in bone fracture is that the tool can comment on physiology. Acute, Sub-acute or chronic part of the fracture is based on edema. A recent or acute fracture will present with a lot of edema. This is a physiological process.

Technical Aspects of MRI

Magnetic Resonance Imaging technologies developed from Nuclear Resonance which is used to evaluate chemical composition of lab samples. Raymond Damadin first produced a full body MR image in 1976. Damadin did some market research. He noticed that people were reacting to the word nuclear (in a bad way). The name later changed to MRI.

Random MRI Tidbits

The most common reason for a patient not to get an MRI is claustrophobia. Sometimes people don’t know that they are claustrophobic. Contrast agents can be used with MRI. There can be piped in music inside the tube using headphones and speakers. 9 Tesla is the strongest magnet. A typical MRI is 1.5-2.0 Teslas. High field strengths may have some affect on the patient. We don’t know for sure the long term affect of the magnetic strength. We control the voxel in an MRI.

Radiofrequency Coils (RF)

Placed on or near the area of interest

Used to Excite Target Tissue

Also Receives Information Regarding Hydrogen Nuclei Radiation

There is not a full array of coils due to money. The coils can range from over $100,000 to $250,000.

Image Production

Hydrogen is a charged Particle representing 80% of all the atoms in the body

Hydrogen behaves likes a small bar magnet

Hydrogen atoms are randomly oriented and their charges cancel out

We choose hydrogen because it is in many tissues within the body. We can get useful clinical information from it. In a strong field, hydrogen has a north and south pole. We get alignment based on induction of a field and field strength. Once the body is in the field, the body becomes magnetic.

Image Production

Hydrogen Molecules are not held static, but are induced to demonstrate precession (Wobble)

They are aligned but they precess or spin out of phase

The atoms move. They are aligned with the field but may not move in phase.

Image Production

A strict linear relationship exists between the frequency of precession and the MR magnetic field.

The Larmor equation forms the foundation for MR imaging

Frequency of Precession = Gyro Magnetic Ratio * Strength of the External Field

Higher the field the higher the precession

When we add energy (FM) energy, it makes them move together (in Phase) and no longer out of phase.

Resonance and Image Generation

Energy must be added to the system. The Radiofrequency (RF) identical to the Larmor frequency is pulsed into the patient. This is the concept of Resonance. This causes the aligned hydrogen atoms to precess or spin. The RF pulse is turned off and the “exited” hydrogen atoms undergo “relaxation”. This release of excess energy is in the form of radiofrequency and specialized antenna (surface coils) receive the input. Tremendous computer power is now brought to bear and an image is reconstructed.

There is tremendous computer power necessary for making the anatomical images.

1. Radiofrequency Wave Pulsed into Patient

2. The wave aligns hydrogen and the hydrogen atoms spin (precess)

3. The wave is stopped and the atoms begin to relax

4. A radiowave is released from the patient

5. Coils pick up the wave and send the information to the computer

6. The computer generates an image

Imaging Techniques

The MR image appearance is controlled by altering the timing of RF pulses sent into the patient and the returning echo. We use TR and TE to control imaging characteristics for MRI. The appearance of the image reflects the intensity of the emitted signal. High signal intensity appears bright and dark areas represent areas of low signal intensity. Intensity of the signal is determined by the quantity of mobile hydrogen atoms and two magnetic relaxation times.

Manipulating the repetition of administered RF pulses (repetition time, TR) and collection of the emitted RF signal (Echo Time, TE), influences the image characteristics. Images may be described as proton density in which the image is based on the population of hydrogen T1-weighted or T2 weighted, where the specific relaxation characteristics of the various tissues will be highlighted or suppressed.

MRI PULSING SEQUENCES

Weighting TR TE

Proton Long Short

T1 Short Short

T2 Long Long

DX IMAGING – 2/13/08

MRI

T1 PROTOCOLS

TR’s of 200-600 milliseconds approximately

TE’s lasting approximately 25 milliseconds

T2 images are very time consuming protocols and have long TR’s (900-8000 ms) and long TE’s (50-100 ms)

Hybrid images have been developed to take advantage of type 2 images with greater economy of time

MRI takes longer than CT scans. New Spiral CT’s can take 3-5 minutes.

T2 weighted images are what make MRI's take so long. There is a big push to get the time down. The need is to get as many patients through the door as possible. We now are using hybrid images to help with this. MRI may be too versatile to distinguish between the images.

We need to do some investigation before an MRI, because it is very specific. Ex.—There are over 32 causes for the common headache. So when you send someone for a headache, you need to list what type of headache (differential diagnosis) that you are searching for (ex.—muscular tension, vascular, etc.)

MRI Strengths

Superior Resolution

Superior Tissue Contrast

Images Soft Tissue Very Well

Non Contrast Enhancement in the Spinal Canal

Axial Images OK

Coronal, Sagittal, etc. – Images are Superior

When it comes to soft tissue imaging, MRI is the best.

VS.

When it comes to line pairs per unit measurement, X-ray is the best.

MRI’s produce great sagittal, and coronal images. --- Ex. On Overhead -- (Mid Sagittal Image of Brain) – T1 Weighted image (TR and TE are low)….Fat in the sub occipital region/sub occipital triangle appears white (bright color)

MRI Strengths (continued)

MRA can produce non contrast visualization of major and minor vessels

Measurements may be accomplished

MR reports on the Physiology as well as Anatomy

Not Reliant on Attenuation of Ionizing Radiation

No Known Harmful Effects – Exposure is often seen first in the technicians and doctors using the tools, but we haven’t seen harmful effects yet. In strong magnets (9 Tesla) we may see dizziness and nausea, but that passes.

MRA is the first choice study for head and neck vascular issues. Third party payers recognize that finding an early problem is extremely important and reduces cost if a stroke occurs. This will save millions of dollars on after care.

MRI improves the accuracy of measurements. MRI can also report on physiology well. Bone scan can comment on physiology, but the scope is very narrow (it only works on the osteoblastic activity). Protection from ionizing radiation is a big strength of MRI.

HOW TO DISTINGUISH T1 FROM T2

To separate CT from MRI:

1). Use Bone first (look at the cortial layer – if it is black it is MRI…if it is white it is CT)…The lack of signal makes cortical bone black on MRI vs. the signal uptake makes cortical bone white on CT

2). On T1 fluid is dark VS. T2 fluid is white.

3). TR and TE are both lower in T1 than T2…Normal T1 values for TR are 200-600 and 25 for TE

MRI Contraindications

Pace makers

Ear implants – supposed to be titanium alloy with ceramic coating, but outside sources from other countries use metals strongly attracted to the MRI (typically we don’t put the patient in the MRI)

Miscellaneous implanted electronic devices (ex. – insulin pump or pain medication drips or penile implants)

Cerebrovascular clips (Endotheliazed clips held in place by the body may have some torque on the clips and vessels…The key is to know if the manufacturer used titanium alloy or not…Generally, if we don’t know for sure, they don’t get an MRI...They are a candidate for a CT scan)

Machine Shop Workers – Metal shrapnel is part of their occupational hazard. The shrapnel can heat up and be an annoyance. If the shrapnel is in their eyeball, it can be a hazard. If they don’t know if they have shrapnel, no MRI till they have an ionizing scan (CT or X-ray).

Claustrophobia

Orthopedic implants (distorts Gaussian field).

The key to metals is if they are iron (ferrous metal)…If the metal, is iron, it will be strongly attracted to the magnet of the MRI and will interrupt function.

MRI – Contrast

Non-iodinated adverse reactions – Very Rare

Magnetic contrast agents

Gadolinium is the most common agent

Works as a T1 shortening agent which causes tissue containing gadolinium to appear bright on T1

Very useful in cases of : CNS tumor, Multiple Sclerosis, Disc Herniation vs. Scar Tissue

DX. IMAGING – 2/19/08

MRI – Contrast

The kidneys are responsible for clearing most MRI contrast agents. Poor kidney function patients will have trouble clearing the dye.

Iodine based contrast agents have the most frequent bad reactions. The stat is that 3-5% will have bad reactions with iodine. This includes people that have severe allergic reactions possibly leading to anaphylactic shock and requiring epinephrine injections.

Non-Iodinated agents have .1-.3% bad reactions. We still have bad reactions with non-iodinated agents but we have less cases overall by using non-iodinated agents.

Contrast studies can help to identify MS due to the bizarre presentation.

Scar tissue can form around vascular tissue in the spine. The tissue can be visualized best with contrast studies.

As chiropractors we are not allowed to administer the dye injections; however, we can order these studies or refer out to have these studies done.

MRI Tidbits

Fast Imaging Protocols in MRI have improved

1.5 T magnets is considered the minimum

More widely accepted in extremity trauma

Many authors believe that MR should be used with more regularity in the acutely injured spine

ST injury more likely to be identified

Any case presenting with neurological signs should be examined by MR

1.5 Tesla should be considered the minimum. Also, watch out for open MRI’s, as they may not be of sufficient strength. In the acute neurological setting (including head trauma), CT is the modality used, not MRI. In chronic cases, MRI is the study of choice. In MRI, the tissue color can be manipulated even without contrast.

Head or neck vascular problems have MRA as the study of choice. It is cheaper to find the problem before the aneurysm bursts, so intervene early before it costs more later.

fMRI

Blood Imaging Oxygenation Level Dependent imaging (BOLD)

Physiologic processes may be observed: 1). Cortical activation, 2). Retinotopic Organization of the visual cortex 3). Cerebral basis for Language 4). Mapping of the Motor Cortex 5). Memory 6). Study psychiatric disorders

We can choose which molecule we study. We actually check blood oxygenation levels in an fMRI. Working tissue consumes more oxygen than other tissues (primarily we use it for brain studies). The tasks are performed with the patient conscious in the MRI tube.

Memory can be studied on fMRI. We have found that men and women process memory different. Bipolar brains (manic depressants) and schizophrenic brains appear different on fMRI. fMRI is also used for migraine headaches. There can be many causes for the “migraine” headache. fMRI can be used as a screening tool to determine what type of headache the patient assisting them in getting proper care.

Imaging Tools and other cutting edge Technologies

FMRI = cine like imaging (like a real time motion study)

fMRI = BOLD imaging

MR spectroscopy = metabolic activity, neuronal density, deranged metabolic activity, and activity prior to morphologic change

MEG = magnetoencephalography measures weak magnetic fields. Neurophysiologic and cognitive study

CT perfusion = transfer of arterial to venous side

Xe-Ct = patient inhales stable gas; CBF assessed, Vascular occlusion, vascular dilation

*** The above material on cutting edge technology are not testable material ***

7 Categories of Bone Disease

VICTANE

1. Vascular or Hematologic: We can check for ischemic necrosis of bone

2. Infection = Bone is destroyed quickly by infection

3. Congenital = Is this something a patient can be born with or not? Check for contours, dysplasia, etc.

4. Trauma = Is this a normal bone that is broken? Perceive the outlines of the bones and check for fracture planes.

5. Arthritis = Check for arthritides…

6. Neoplasm = Was this bone attacked by aggressive tumors? This may be slower than infection but cause severe damage

7. Endocrine/Nutritional/Metabolic = Can there be a local or generalized endocrinopathy? A general problem may be a global problem and evidence of endocrine/nutritional/metabolic problem

You work by eliminating categories in the VICTANE acronym till you get a diagnosis.

Analysis of the Lesion

Skeletal location – You can highlight or suppress a disease diagnosis by skeletal location

Position within Bone

Site of Origin – Can be metastatic situation (breast cancer has lytic effects on bone it metastasizes to…Thyroid cancer will appear as “soap bubbles” appearance on the bone

Shape – Longer the lesion, the less the effect it can have on cortex and usually the more benign it is…when lesions break through the cortex they are generally aggressive

Size – Every big aggressive lesion starts off as a small lesion, so size does not necessarily determine malignancy. It is a small factor and small piece of information, so use weight of the evidence.

Margination – Sharply marginated usually means the body tries to react to wall off the area…Great difficulty in finding the margins usually shows a long zone of transition (these are aggressive processes)

Cortical Integrity – Cortex intact = early or benign….Cortex not intact = late or aggressive

Behavior of the lesion – What does the lesion do to soft tissues

Matrix – Fibrous lesions never take up calcium, but osteoids do pick up calcium. Chondral lesions do pick up some calcium but not as much as osteoid

Periosteal response – Adult patients with periosteal responses need to be monitored. .It is easier to see a periosteal response in children. At skeletal maturity, Sharpey fibers attach the periosteum to the bone. In children, the periosteum can be injured with greenstick fracture.

Soft Tissue Changes – Ex. AAA…Can scallop the vertebra and surrounding structure

Joint Changes – A key finding to differentiate between tumor and infection. Tumors do not affect the joint, but infections keep working through the joint and onto the adjacent bone. Infections respect no body and no gender, but we have different sets of tumors for different ages, genders, etc.

Preliminary Analysis of Lesion

Clinical Data: Age, Sex, Race, History

Number of lesions

Symmetry of lesions

Systems Involved

Supplementary Analysis

Other radiologic procedures

Laboratory Examination

Biopsy

*** CH 7 Table for Tumors ***

Benign Primary Secondary (metastasis)

Age 1, 2, 3 1-7 4, 5, 6, 7

Size

0-6 +++ + +

6+ + +++ +++

Monostatic +++ +++ ++

Polyatomic + + +++

Cortical Destruction - +++ +++

Periosteal Reaction

Solid +++ + -

Laminated (layers of periosteum) ++ ++ -

Spiculated - +++ +

Codman’s ++ ++ +

Destruction

Geographic +++ + -

Motheaten - +++ +++

Permeative - +++ +++

Margins

Sharp +++ + +

Imperceptible - +++ +++

Matrix +++ ++ -

Soft Tissue Mass - +++ +

Joint Space - - -

Codman’s Cuff = should never be associated with a benign finding. It used to be laminated and it grew so fast it blew through. This is the most aggressive pattern of growth. The tumor pokes through the laminated pattern

Lamination = a sign the body can’t fight something off. The body tries to wall of the lesion, but it can’t.

Spiculated pattern = are reserved for aggressive tumors. The periosteum is shredded and pointed away from the bone. There is dystrophic calcification seen in the bone in this speculated pattern.

Periosteal lesion = probably pathological fracture repair. The body wants to repair it with callus formation, not with true periosteal formation. Most benign periosteal lesion do not produce reactions.

Benign= grow so slow that the body can resist progress so that we can wall them off = geographic (sharply marginated, short zone of transition)

Permeative = happens before motheaten…These are pinholes about 1 mm in the bone. The pinholes continue and grow

Motheaten = the next phase of permeative (2nd phase of permeative). Tumor pokes hole in cortex. The margins coalesce and present as tooth marks/bites in the bone. You cannot separate primary from secondary motheaten.

Soft Tissue Mass = Only seen in primary cancers. This is the only site where a tumor can break out of containment. Benign lesions contain the process and we can’t see soft tissue extension.

Joint Space = Absent for all categories. Tumors do not affect joint spaces. Infection affects joint spaces (nobody and no boundaries).

- Absent….+ Occasional…++ Common….+++ Very Common

1,2,3, etc. = Decades

DX. IMAGING – 2/20/08

*** Test Materials Ends with the Tumor Chart Above ***

*** Test is next Tuesday…Test will be given during 2 sessions (3rd and 4th periods)….There will be a 25 question slide exam (with 15 multiple choice and 10 fill in the blank), followed by a multiple choice exam (40 questions ***

*** Notes from 2/20/08 will be included on the note packet for the final exam ***

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