Download SMU-DDE-Assignments-Scheme of Evaluation PROGRAM Bachelor

SMU-DDE-Assignments-Scheme of Evaluation
PROGRAM
SEMESTER
SUBJECT CODE &
NAME
BK ID
SESSION
MARKS
Q.No
1.
A
Bachelor/Diploma in Medical Imaging Technology
IV
BMI 404– Radiographic Techniques: Special Procedures- II
B2052
WINTER 2015
60
Criteria
Marks
Total
Marks
Discuss the positioning and technical considerations of mammography.
(Unit 2;Section 2.3;Pg 34-43 )
10
10
 Mammography is a specialty within itself, essential for the detection
and management of breast disease.
A. Patient preparation: Before the examination begins, the radiographer
will explain the procedure and ask the patient to put on a gown,
preferably one designed for mammography that allows exposure of only
the breast that is being examined. The patient will be instructed to
remove any jewelry, talcum powder, or antiperspirant that may cause
artifacts on the radiographic image. The radiographer will document
relevant patient history as per the departmental protocol.
 Generally this patient history will include the following: Pregnancy,
number of pregnancies, Family history of breast cancer, Medications
(e.g. Hormone therapy), Previous surgery, Previous mammograms,
when and where performed, Description of problem, such as
screening mammogram, lumps, pain and discharge.

The radiographer should also note the locations of scars, palpable
mass, moles, warts, tattoos, etc.
B. Breast positioning: In mammography, the great variability of the
breast, with respect to the proportion of fatty tissue to fibro-glandular
tissue, presents certain technical difficulties. In producing a superior
quality mammogram, the shape and contour of the normal breast poses
additional problems to the radiographer. The base of the breast is that
portion near the chest wall, whereas the area near the nipple is termed
the apex. In either the craniocaudad or the mediolateral projection, the
base of the breast is much thicker and contains much denser tissues than
at the apex.
To overcome this anatomic difference, compression is used in
combination with a specially designed tube so that the more intense
central portion of the x-ray beam (CR) penetrates the thicker base of the
breast.
C. X-ray tube: The most distinctive aspect of the mammography
machine is the unique design of the x-ray tube, which has a molybdenum
SMU-DDE-Assignments-Scheme of Evaluation
target with small focal spots of 0.3 and 0.1 mm. Rhodium has recently
been introduced as an optional anode material. The focal spots must be
this size because of the size of the cancer calcifications, which are
typically less than 1.0 mm in size.
The anode configuration produces a prominent heel effect resulting from
the short source-to-image receptor distance (SID) and the use of a
narrow reference target angle. Because the x-ray tube is aligned with the
cathode placed over the base of the breast (at chest wall) and the anode
outward toward the apex (nipple area), the heel effect fortunately can be
used to maximum advantage. Because the cathode side of the x-ray beam
has significantly greater intensity of x-rays compared with the anode
side, a more uniform-density breast image can be produced, because the
more intense x-rays are at the base, where tissue thickness is greater.
Most mammograms utilize grids, automatic exposure control (AEC), and
the important breast compression device.
Automatic exposure control (AEC) chamber selection: The AEC pick-up
chambers on most mammography systems are adjustable in up to 10
positions from the chest wall to the nipple region. To ensure adequate
penetration of the more dense/thick crust wall tissues, the chamber of the
chest wall should be selected. The only exception to this is for special
projections, such as magnification and spot compression views.
Note: Vertical CR is placed directly over the chest wall structures, which
allows the poster superior breast structures to be imaged.
D. Compression: All mammography machines contain a compression
device that is used to compress the breast as shown in figure 1.7.
Improvements in breast compression technology in recent years have
greatly improved the visibility of detail in breast images. The
compression device is made of a plastic that allows transmission of the
low-energy x-rays. The device should have a straight chest wall edge to
allow the compression to grasp the breast tissues close to the chest wall.
Compression is controlled by the radiographer and is typically applied at
25 to 45 pounds of force.
In addition to the standard compression device, a smaller “spot” device
may be used to compress localized areas. The compression device
should be checked regularly to ensure that it is working properly and
applying the correct amount of pressure.
Appropriately applied compression is one of the critical components in
the production of a high quality mammogram. The two part function of
compression is to (1) decrease the thickness of the breast and (2) bring
the breast structures as close to the IR as possible. These two factors
improve image quality or resolution by reducing scatter and also by
SMU-DDE-Assignments-Scheme of Evaluation
reducing magnification of breast structures.
E. Magnification: The magnification method is used to enlarge specific
areas of interest such as small lesions or micro calcifications. This
requires an x-ray tube with a 0.1 mm focal spot to maintain image
resolution. Enlargements of 11/2 to 2 times can be used by inserting a
magnification platform between the image receptor and the breast,
thereby, magnifying the part resulting from increased object-image
receptor distance (OID).
F. Patient dose: Patient dose is significant in mammography. A skin dose
of 800 to 900 m rad and a mean glandular dose (MGD) of 130 to 150 m
rad are common for a 4 cm thickness mammogram, which is much
higher than for most other body parts. For example, a much thicker 30
cm lateral lumbar spine at 90 kVp, 50 mAs, has a skin dose of 1000 to
1300 and a midline dose of 130 to 180 m rad. The reason for the
relatively high dose for mammograms is the very low kVp (25 to 28) and
the high mAs (75 to 85) required.
The principal way patient dose is controlled in mammography is by
careful and accurate positioning, which minimizes the need for repeats.
The ACR (American College of Radiology) recommends a repeat rate of
less than 5% for mammography. The only shielding possible is a waist
apron for shielding the gonadal region.
2.
Explain laryngography and bronchography in detail.
A

(Unit 3;Section 3.3 & 3.4 ;Pg 39-45)
5
10
Laryngography is the examination of the larynx and hypopharynx by
coating with a contrast medium after premedication and local
anesthesia.
 The laryngograph is a device used to provide information on vocal
fold contact and this technique is non-invasive and easy to use.
 This method gives the experienced radiologist the most information
about the lumen of the larynx, the mobility of the true and false
vocal cords, the subglottic spread of tumors, etc.
 The contrast media used are the same as those used for
bronchography.
 The contrast medium is administered via a cannula in the larynx drop
by drop until the entire larynx and hypopharynx are covered with a
thin coating.
 Radiographs are subsequently made under fluoroscopic control in the
postero-anterior and lateral projections while the patient successively
inhales slowly, phonates, pushes against the closed glottis, and
carries out Valsalva’s manoeuvre with closed mouth and nose.
 This examination requires calm preparation, but the radiographs
themselves are taken within several minutes. The examination can
be supplemented with radio cinematography or video-recording to
assess once again the mobility of the vocal cords.
Bronchography is a study performed to delineate the bronchial tree by
5
SMU-DDE-Assignments-Scheme of Evaluation
introducing a radio opaque contrast medium into the bronchial tree.
Bronchography is rarely performed, as it has been made obsolete with
improvements in computed tomography and bronchoscopy.
Indications
1. To confirm the diagnosis of bronchiectasis and to assess the extent
of disease.
2. In few cases of haempotysis is which chest X-ray and bronchoscopy
examination are normal.
3. Expiratory collapse of trachea and bronchi, which is an important
cause of air flow obstruction. This is poorly assessed endoscopically
and is well demonstrated by cine and by video bronchography.
4. Bronchographys is occasionally employed for the assessment of the
bronchial tree in patients with chronic emphysema or fibro thorax
prior to decortication.
5. Localized emphysema
6. Bronchopleural fistula
7. Cough of unknown etiology
8. Repeated episodes of pneumonia
9. Unilateral hilar adenopathy in an adult with/without associated
pulmonary lesion.
Contraindications
1. Infections: For example, acute pneumonia. Incomplete filling of the
diseased bronchial tree due to secretions, exudates, etc. interferes
with the diagnostic accuracy of the bronchogram. In addition, the
infections may be further exacerbated.
2. Severe recent hemoptysis: The presence of blood clots can interfere
with the diagnostic accuracy of bronchography by causing false
obstructions of confusing intrabronchial shadows.
3. Heart failure.
4. Marked impaired pulmonary function.
5. Iodine sensitivity.
6. Patients in whom radioactive iodine studies are planned.
Bronchography has never been an emergency procedure and it is best to
postpone or cancel the examination if any one of the above is present.
Preparation
1. The status of pulmonary function should be known (vial capacity,
forced expiratory volume).
2. The patient is nil orally 4 hours prior to the examination.
3. If the patient is producing copious amounts of sputum, postural
drainage prior to the examination is desirable.
4. Though slight sedation is desirable, it is important that the patient
SMU-DDE-Assignments-Scheme of Evaluation
remains alert and co-operative though out the procedure. Oral
diazepam (10 mg) may be given 3-4 hours prior to the procedure
especially if the patient is apprehensive.
5. Atropine 0.6 mg I.M. is given 30 minutes prior to procedure. It
minimizes the amount of secretions.
3.
A
Requirements: Topical anesthesia and contrast media.
Describe the various specific angiographic procedures.
(Unit 4;Section 4.3;Pg 61-65)
10
10
1. Computed Tomography (CT): Volume acquisition, sub second
reconstruction of images, and sophisticated software has made CT a
valuable tool in vessel assessment. Computed tomography is used to
study aortic aneurysms and (if equipment specifications permit) is useful
in pulmonary embolism diagnosis.
CT angiography (CTA) is a study that provides images of the vascular
structures in cross-section, which, depending on the capability of the
scanner and software, can be reconstructed into a 3D image. CTA
provides the advantage of contrast administered intravenously,
eliminating the need for an arterial puncture and catheter insertion.
2. Nuclear medicine: Nuclear medicine technology is often used in
conjunction with angiography in investigation of certain cardiovascular
pathologies, some of which include pulmonary embolus, Gl bleed,
renovascular hypertension, and coronary artery disease. Nuclear
medicine complements other imaging modalities because it provides
primarily physiologic information but little anatomic detail.
3. Ultrasound (sonography): The role of ultrasound in cardiovascular
imaging has increased. Ultrasound may be used to image the patency of
vessels and demonstrate thrombus formation, plaque, or stenosis. Color
Duplex (color flow Doppler) is also used in ultrasound to demonstrate
the presence and absence of flow within a vessel, the direction of flow,
and with more sophisticated equipment, and the velocity of flow.
Echocardiography provides detailed images of the heart for investigation
of numerous cardiac conditions, including valve disease, aneurysm,
cardiomyopathy, myocardial infarction, and congenital defects.
4. Magnetic Resonance Imaging (MRI): Magnetic resonance
angiography (MRA) provides highly detailed images of the patient’s
vasculature. This is advantageous as contrast media is not required and a
vessel puncture is avoided.
5. CO2 angiography: As an alternative to iodine based contrast media,
CO2 is being used at some centers for selected procedures when
iodinated contrast agents are contraindicated. This could include patients
SMU-DDE-Assignments-Scheme of Evaluation
with cardiopulmonary disease, diabetes mellitus, or renal insufficiency.
The use of CO2 as a contrast agent is also indicated for patients who
have a history of allergic reaction to iodinated contrast.
Specialized CO2 injectors have been developed to provide accurate, well
– timed delivery of the gas into the vessels being examined. Some
angiographic equipment has specialized digital imaging software to
optimize the use of CO2.
4.
A
Certain limitations and risks are associated with CO2 angiography but
the use of CO2 as a contrast agent is expected to find greater application
in the future.
Explain knee arthrography in detail.
(Unit 8;Section 8.3;Pg 107-111)
Knee arthrography is performed to demonstrate and assess the knee joint
5+5
10
and associated soft tissue structures for pathologic processes.
Pathologic indications: Knee arthrography is indicated when tears of
the joint capsule, menisci, or ligaments are suspected. The knee is a joint
subject to considerable stress, especially during sports activities.
Contraindications: In general, arthrography of any joint is
contraindicated when the patient is known to be allergic to an iodinebased-contrast medium or to local anesthetics.
Patient preparation: Any arthrographic procedure should be
thoroughly explained before the examination proceeds to preclude
unnecessary anxiety on the part of the patient. The patient should be
advised of any complications and must sign an informed consent form.
Major equipment: The major equipment for knee arthrography varies
with the method of imaging. Image acquisition is obtained during
fluoroscopy and can be conventional spot films or digital images. The
radiographic room used must be equipped so that horizontal – beam
radiography can be accomplished.
Accessory equipment: Accessory equipment for examination of the
knee varies according to the method of imaging, except for those items
needed for the contrast injection and preparation of the injection site.
These items are basically the same for any arthrogram tray.
Contrast media: Knee arthrography can be accomplished by use of a
radiolucent (negative) medium, a radiopaque (positive) medium, or a
combination of both media (dual contrast). The dual – contrast study
seems to be the method of choice for this study a very small amount
(approximately 5 cc) of a relatively low – density positive medium is
used, along with 80 to 100 cc of a negative medium such as carbon
dioxide, oxygen or room air.
Positioning routines
SMU-DDE-Assignments-Scheme of Evaluation
5.
Radiographic routines: The routine positioning and procedure for knee
arthrography varies with the method of examination, such as,
fluoroscopy, conventional radiography, or a combination of both.
 Fluoroscopy/spot filming or digital fluoroscopy/imaging: During
fluoroscopy the radiologist usually takes a series of closely
collimated views of each meniscus, rotating the leg approximately
200 between each meniscus, which demonstrates the meniscus in
profile throughout its diameter. If digital fluoroscopy and imagine
are used the images are stored on a computer’s hard drive for final
viewing and printing to hard copy.
 Conventional “Overhead” projections: In addition to the spot films
or digital fluoroscopy imaging, routine AP and lateral radiographs of
the entire knee, utilizing the radiographic tube, are usually included.
These images are obtained after removal of the Ace bandage from
the distal femur.
 Horizontal – beam projections: Horizontal – beam radiography is
another common method of imaging for knee arthrography and
requires some special equipment (Refer fig. 10.7), including the
following:
a) Six views of each meniscus.
b) Low, small table or stand for use during radiographing of the
lateral meniscus; a firm pillow 5 lb sandbag.
c) These last two items are used to open up the appropriate area of
the joint space to visualize the lateral and medial menisci.
d) Each meniscus is radiographed on one film, with the patient’s
leg rotated 300 between each exposure. The resulting
radiograph demonstrates six views of each meniscus, in profile,
throughout its diameter.
Define myelogram. Discuss the indications, contraindications, preparation, requirements,
contrast media, positioning and filming in myelogram.
(Units 4;Sections 4.3 ,Pg 61-65 )
SMU-DDE-Assignments-Scheme of Evaluation
A
Definition
Myelogram or Myelography is a study in which contrast medium is
injected into spinal subarachnoid space to study the structural details of
spinal cord, conus medullaris, nerve roots and spinal canal.
Indications
1) Suspected mass lesion with or without any compressive
myelopathy.
2) Disc lesion-protrusion/herniation.
3) Spinal deformities and obliteration of spaces by previous surgery,
arachnoiditis.
4) Congenital lesions.
5) Spinal canal stenosis.
6) Degenerative diseases-posterior osteophytes.
7) Injury-fractures.
8) Localised lesions at any level of spinal cord.
9) Urinary bladder and bowel disturbances.
10) Back pain radiating to the limbs.
Contra-indications
1) Raised intracranial tension.
2) Iodine sensitivity (allergy).
3) Recent lumbar puncture (up to 7 days).
4) Local sepsis: manifest or suspected infection of the tissue overlying
the lumbar theca.
5) Clotting disorders or patient on anticoagulants.
6) Traumatic lumbar puncture where blood odes not clear off is a
contra indication to injection of contrast medium.
Preparation
a) 4 hours fasting prior to procedure.
b) Informed consent from the patient.
c) Plenty of oral fluids on the previous day.
d) Preparation of site for lumbar puncture.
e) Xylocaine sensitivity testing.
Requirements
a) Lumbar puncture set including needles: 18G, 19G, 20G, 12G, and
22G.
b) Contrast media and 10 cc disposable syringe.
c) LP needle which has a short bevel angle of 45 degrees, as long bevel
needles result in extravasation of contrast during injection and
should not be used.
1
1
1
1
2
10
SMU-DDE-Assignments-Scheme of Evaluation
Contrast media
A. Water soluble non-ionic contrast media: E.g. Iohexol-Omnipaque;
Iopamidol-Iopamiro.
B. Oily contrast media
1
Positioning and filming: While doing myelogram, make sure the head
end is always at a higher level than the contrast column.
Lumbar myelogram: Table tilt: Slowly tilt the head end up, usually 1530 degree head up tilt is required. However, if a near total block exists
3
Patient position: In left lateral position, sacral cul-de sac fills with
contrast. Take the 1st lateral film at this time. Then the patient is turned
prone and the frontal film of lumbo-sacral region is exposed. The table
tilt is reduced to 10root sleeves. The patient is turned 20and a film is exposed to demonstrate the left sided root sleeves. Then an
identical opposite oblique view is taken to show the right sided root
sleeves.
6.
Discuss tomography in detail.
A

Tomography is a special type of imaging used to obtain a diagnostic
image of a specific layer of tissue or object that is superimposed by
other tissue or object. Tomography refers to imaging by sections or
sectioning, through the use of any kind of penetrating wave. A
device used in tomography is called a tomography, while the image
produced is a tomogram.
 Tube Trajectories: There are five basic types of trajectories for tube
movement in tomography. These are listed from simplest to most
complex as follows:
a) Linear
b) Elliptical
c) Circular
d) Spiral
e) Hypocycloidal
Explanation of all the above types of tube trajectories.
A. Linear unidirectional tube trajectories: Linear or unidirectional
tomography involves the least complex type equipment setup. This
procedure utilizes a basic x-ray table with Bucky tray and overhead tube
connected by a metal connecting arm or rod. This rod passes through an
adjustable fulcrum level attachment. This attachment is used to manually
or electrically adjust the height of the fulcrum level. Tube movement is
achieved by a motor attached to the unit. Because the tube moves along
the longitudinal axis of the table, the longitudinal tube lock must be
opened (unlocked). The Bucky tray angle locks must also be opened to
permit these items to move freely.
B. Multidirectional
tube
trajectories:
Of
the
four
types
of
(Unit 8; Pg 127-140)
1
10
4
SMU-DDE-Assignments-Scheme of Evaluation
multidirectional movement, the least complex is the elliptical, which is a
slight variation from the linear. The circular movement is “a step above”
the elliptical pattern in complexity. The two most complex
multidirectional movements are spiral and hypocycloidal. The more
complex the multidirectional movement, the thinner is the possible
objective plane and the clearer is the image.
3
Explanation of Fulcrum and blur
2
Tomographic applications
*A-Answer
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