X-Ray Studies
OVERVIEW OF X-RAY STUDIES
X-ray studies, also known as radiographs, are used to examine soft and bony tissues of the body. X-rays are short-wavelength electromagnetic waves produced when fast-moving electrons collide with substances in their pathways. X-rays travel in straight lines at the speed of light (186,000 miles/second). When an x-ray beam passes through matter, some of its intensity is absorbed—the more dense the matter, the greater the degree of x-ray absorption. The composite image produced represents these varying degrees of tissue density in shades of black, white, and gray. Images may be captured on photographic film, displayed on a video screen, or recorded on digital media. The basic principle of radiography is that differences in density among various body structures produce images of varying light or dark intensity, much like the negative print of a photograph. Dense structures appear white, whereas air-filled areas are black.
USE OF CONTRAST AGENTS
Many radiographic techniques use the natural contrasts and varying densities that exist in body tissues representing air, water (in soft tissue), fat, and bone. The lungs and gastrointestinal (GI) tract normally contain air or gases. Other body structures are encased in a fatty envelope. Bone contains naturally occurring mineral salts. However, diagnosis of certain pathologic conditions requires visualization of details that cannot be revealed through plain x-rays. In these cases, details can be highlighted by the presence of contrast media in the area. These contrast substances can be administered through oral, rectal, or injection administration.
The ideal contrast agent should be relatively harmless (low toxicity, nonantigenic, nonallergenic, and inert), should not interfere with any physiologic functions, and should allow high and repeated dosing at a moderate cost. A contrast medium may be classified as either radiopaque (not permitting the transmission of x-rays) or radiolucent (permitting partial transmission of x-rays). The adverse pharmacodynamics of contrast media causes death in an estimated 1 of every 20,000 to 40,000 administrations. The most commonly used contrast agents are water-soluble noniodine agents for GI examinations and intravascular procedures. Ultimately, one must always be alert to the possibility of an adverse reaction to contrast media. Consequently, emergency supplies and equipment should be readily available when using these agents.
The following contrast agents are used routinely in x-ray studies:
Alimentary canal contrast agents
Water-soluble agents (e.g., Gastrografin, Gastroview, Hypaque sodium oral powder)
Water-insoluble agents (e.g., BaSO4, Polibar Plus, Esophotrast, Anatrast)
Gases (CO2 gas, gas-producing calcium citrate and magnesium citrate)
Injectable contrast agents
Nonionic iodinated contrast (low osmolar agents; e.g., Omnipaque, Optiray)
Ionic iodinated contrast (high osmolar agents; e.g., Renavest, Hypaque, Conray)
Specific-use agents
Bile agents (Cholebin, Conray)
Iodized oil contrast agents
ADVERSE REACTIONS TO CONTRAST AGENTS
All contrast agents have the potential for causing allergic reactions that can range from mild (e.g., nausea and vomiting) to severe anaphylaxis (e.g., cardiovascular collapse and central nervous system depression leading to death if untreated). Table 10.1 lists the range of possible adverse reactions to iodine contrast media. Reactions happen quickly and usually occur within minutes of administration of the contrast agent. Such reactions can occur in anyone.
TABLE 10.1 Signs, Symptoms, and Incidence of Reactions to Iodine Contrast Media | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Clinical Considerations When Iodine Contrast Agents Are Used
Know the patient’s age and health status. Children and elderly people, especially those with medical problems, may be especially sensitive to contrast agents. This sensitivity may increase the chance for side effects.
The presence of other medical problems may increase the risk for side effects.
Individuals with asthma or hay fever are at a greater risk for having an allergic reaction to the contrast agent.
Diabetic patients have a greater risk for developing kidney problems.
Those with severe hypertension may experience a dangerous rise in blood pressure and tachycardia.
Patients with kidney and liver disease may experience exacerbation of their disease.
Individuals with multiple myeloma may develop severe kidney problems.
Those with overactive thyroid may experience a sudden increase in symptoms or thyroid storm.
Those with sickle cell disease may experience the formation of abnormal blood cells.
Patients using β blockers may have a higher risk for developing anaphylactoid reactions.
Patients with chronic obstructive pulmonary disease (COPD) have an increased risk for postinjection dyspnea.
Patients who are allergic to iodine contrast media must have this information documented in their health care records. The risk for subsequent reactions increases three to four times after the first reaction; however, subsequent reactions will not necessarily be more severe than the first. The patient must be made aware of the implications of the situation. Assess for and document allergies to iodine-containing substances (e.g., seafood, cabbage, kale, raw leafy vegetables, turnips, iodized salt). Also determine each person’s reaction to penicillin or skin test for allergies because these patients have a greater chance of having a reaction.
Check the patient’s fasting status before the x-ray procedure has begun. Except in an extreme emergency, iodine contrast media should never be administered intravenously sooner than 90 minutes after the patient has eaten. In most instances, the patient should fast the night before undergoing any x-ray procedure using an iodine contrast agent.
Death from an allergic reaction can occur if severe symptoms go untreated. Staff in attendance must be qualified to administer cardiopulmonary resuscitation should it be necessary. Emergency equipment and supplies must be readily available.
Promptly administer antihistamines per physician’s order if mild to moderate reactions to iodine contrast substances occur (see Table 10.1).
When coordinating x-ray testing with a contrast agent, keep in mind that studies using iodine and those using barium should be scheduled at different times.
Some physiologic change can be expected when an iodine contrast substance is injected, as during an intravenous pyelogram (IVP). Physiologic responses to iodine given intravenously include hypotension, tachycardia, and arrhythmias. For this reason, always check blood pressure, pulse, and respiration before and after these tests are performed.
If appropriate for the patient, encourage intake of large amounts of oral fluids after the test to promote frequent urination. This flushes the iodine out of the body.
Possible contraindications to the administration of iodine contrast substances include the following conditions:
Hypersensitivity to iodine
Sickle cell anemia (use may increase sickling effect)
Syphilis (use may lead to nephrotic syndrome)
Long-term steroid therapy (iodine substances may render part of the drug inactive)
Pheochromocytoma (may produce sudden, potentially fatal rise in blood pressure)
Hyperthyroidism
COPD
Multiple myeloma
Acute asthma
History of renal failure
Pregnancy
Diabetes mellitus
Severe dehydration
Congestive heart failure
Drug therapy known to be nephrotoxic (e.g., cisplatin)
Nonionic contrast agents tend to produce fewer side effects than do ionic materials.
Patients with renal failure may develop acidosis when iodine contrast is administered.
CLINICAL ALERT
Careful patient preparation considers patient safety, prevents complications, and can prevent repeat procedures. Assess for the following risk factors associated with a higher incidence of undesirable contrast agent reactions:
Allergy
Asthma
Previous reactions to contrast media
Repeat and high dosages administered
Diabetes mellitus
Renal failure (preexisting); many laboratories require preprocedural assessment of creatinine levels in older adults
Liver insufficiency
Multiple myeloma
Dehydration
Older adult (>65 years)
Newborns
History of seizures
Pheochromocytoma
No contrast agent is without risk for causing reactions. Benefit versus risk must be considered. For example, in a workup to detect cancer, the benefits of early detection far outweigh the dangers of cumulative radiation exposure. The patient must be informed of the risk-to-benefit ratio; the patient has a legal right to this knowledge. In instances in which contrast must be delivered to high-risk patients, prophylactic premedication with prednisone may be ordered. Consult the radiology department for further information.
Never inject iodized oils or barium into the bloodstream.
Contrast agent-induced acute renal insufficiency is a rare and dangerous complication that occurs 1 to 5 days following intravenous injection of a contrast medium. Dehydrated patients and those with serum creatinine levels >1.4 mg/dL (>123.8 µmol/L) are at greatest risk.
Intravascular iodinated contrast may interact with certain intravenous (IV) medications. These interactions produce insoluble precipitates that may lead to embolism. For that reason, an existing IV line should be flushed with saline before using this line as the mechanism for delivering contrast.
Special attention is necessary for diabetic patients because of their increased potential for renal failure and development of lactic acidosis. Diabetic persons taking oral hypoglycemic metformin (Glucophage) should have this drug withheld the day of and 48 hours following the
injection of iodinated contrast. In addition, advise the patient that his or her serum creatinine level should be rechecked 24 to 48 hours after he or she has received parenteral contrast. Examinations requiring extremely small volumes of contrast (myelography, arthrography) may not require such stringent precautions. Check with the radiology department for specific instructions.
Tests for thyroid function (serum tests as well as nuclear medicine studies) are adversely affected for several weeks to months following iodinated contrast injection.
Late reactions (2-3 days after procedure) most often occur with the use of agents such as iotrolan and iodohexane for intravascular procedures such as angiography.
Clinical Considerations When Barium Contrast Is Used
There is always some risk when introducing barium sulfate or a similar contrast agent into the GI tract.
Barium radiography may interfere with many other abdominal examinations. A number of studies—including other x-rays, tests using iodine, ultrasound procedures, radioisotope studies, tomograms, computed tomography (CT), and proctoscopy—must be scheduled before or several days following barium studies. Consult with the radiography department for the proper sequencing of studies.
Increased consumption of fluids will help to clear the bowel of barium.
Elderly, inactive persons should be checked for stool impaction if they fail to defecate within a reasonable length of time after a barium procedure. The first sign of impaction in an elderly person is fainting.
Observe and record findings regarding stool color and consistency for at least 2 days to determine whether barium has been evacuated. Stools will be light in color until all barium has been expelled. Outpatients should be given a written reminder to inspect their stools for at least 2 days following barium administration.
If possible, avoid giving narcotics, especially codeine, when barium x-rays are ordered because these drugs can cause decreased bowel motility that can compound possible barium-associated constipation.
CLINICAL ALERT
Rare instances of severe allergic reactions to barium sulfate have been reported. All patients should be questioned regarding their allergic history before administration of any type of contrast agent. A history of hay fever, asthma, and other allergies places the patient at higher risk for reactions to all types of contrast agents.
The risk for postprocedure constipation or blockage of the bowel is increased in patients with the following conditions:
Cystic fibrosis
Dehydration
Acute ulcerative colitis
Barium should not be used for intestinal study in the following circumstances:
When a bowel perforation is suspected
Following sigmoidoscopy or colonoscopy, especially if a biopsy was performed, because leakage of barium from the alimentary canal can cause peritonitis. Iodinated contrast should be used in these cases.
There are special clinical considerations for ostomy patients undergoing bowel preparation for GI studies; exam preparation and procedure should be tailored by the primary care provider and the radiology department to achieve the most optimal outcomes. In most cases, standard dietary and medication restrictions apply, but modifications involving mechanical bowel cleansing with enemas and physiologic cleansing with laxatives may be necessary.
PROCEDURAL ALERT
Enemas and laxatives should not be given to a person with an ileostomy in preparation for x-rays or endoscopy (see Chapter 12) because this puts the person at risk for dehydration and electrolyte imbalance. The person with a sigmoid colostomy requires irrigation of the stoma the night before and the morning of the study. Consequently, it is important to identify the type of surgical procedure the patient has undergone. Moreover, not all colostomies need irrigation. For example, a person with an ascending right-sided colostomy will usually pass a liquid, pasty stool high in water content and digestive enzymes—such a patient may only require laxatives.
Notify the radiology department that the person has an ostomy.
Advise all patients to bring extra ostomy supplies and pouches for use after the procedure is completed.
RISKS OF RADIATION
Exposure of the human body to radiation carries certain risks. The biologic effects of ionizing radiation change the chemical makeup of cells, causing cell damage and mutation and promoting carcinogenesis. However, not all forms of radiation are equal in the potential for causing damage, and often no perceptible or long-lasting damage occurs. As a general rule, the higher the dose, as determined by the “strength” of the radiation and the duration of the exposure, the greater the risk.
Deterministic effects, such as erythema, nausea, fatigue, depressed sperm count, and temporary sterility occur due to significant cell damage or death that occurs after a threshold amount of radiation has been exceeded. The severity of deterministic effects increases as the exposure dose increases. Stochastic effects, such as cancer, are associated with long term low-level exposure to radiation. Low doses of radiation received over a period of time can lead to radiation-induced malignancy and genetic effects and are of most concern in diagnostic radiology. Because the embryo is most radiosensitive during the first trimester of pregnancy, special precautions must be taken to prevent or minimize radiation exposure to the pregnant uterus (Tables 10.2, 10.3, 10.4 and 10.5).
TABLE 10.2 Principal Early Effects of Radiation Exposure on Humans and Approximate Threshold Dose | ||||||||||||||||||||||||
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TABLE 10.3 Relative Risk for Childhood Leukemia After Irradiation in Utero by Trimester | ||||||||||||
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Safety Measures
Certain precautions must be taken to protect patients, visitors, and staff from unnecessary exposure to radiation.
General Precautions
The patient’s medical records should be reviewed for previous radiological studies to minimize the potential for unwarranted repeat studies.
The size or area irradiated must be carefully adjusted so that no extra tissue than necessary is exposed to the x-irradiation. Collimators (shutters), cones, or lead diaphragms can ensure proper sizing and x-ray exposure area.
Fluoroscopy yields a higher dose than radiographs or CT studies. Significant dose reduction is achieved by employing pulsed digital fluoroscopy.
The gonads should be shielded in both female and male patients of childbearing age unless the examination involves the abdomen or gonad areas.
The primary x-ray beam should pass through layers of aluminum adequate to filter out low energy radiation while still providing detailed images.
Staff in the radiology department should wear lead aprons (and gloves if indicated) when not within a shielded booth during x-ray exposures. Patients should be shielded appropriately insofar as the procedure allows.
The x-ray tube housing should be checked periodically to detect radiation leakage and to indicate when repairs or adjustments are necessary.
TABLE 10.4 Summary of Effects After 10-rad in Utero | ||||||||||||||||||||||||||||||||
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TABLE 10.5 Representative Radiation Quantities From Various Diagnostic X-Ray Procedures | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Precautions to Be Used With Pregnant Patients
Women of childbearing age who could possibly be in the first trimester of pregnancy should not have x-ray examinations involving the trunk or pelvic regions. A brief menstrual history should be obtained to determine whether a possible pregnancy exists. If pregnancy is possible, a pregnancy test should be done before proceeding with x-ray examination.
All pregnant patients, regardless of trimester, should avoid radiographic, fluoroscopic, and serial film studies of the pelvic region, lumbar spine, and abdomen if at all possible.
Should x-ray studies be necessary for obstetric regions, repeat images should be avoided.
If x-ray studies of nonreproductive tissues are necessary (e.g., dental x-rays), the abdominal and pelvic region should be shielded with a lead apron.
Responsibilities in Ordering, Scheduling, and Sequencing X-Ray Examinations
Correct and complete information should be entered into the computer or on the x-ray requisition. An appropriate order will include the name of the exam, the ordering physician’s name, and the clinical indication for the exam. Explain to the patient the purpose and procedure of the x-ray examination. Written patient instructions may be helpful.
When a complete genitourinary (GU) and gastrointestinal (GI) workup is scheduled, the sequence of x-ray procedures should follow a definite order:
First day: intravenous pyelogram (IVP) and barium enema
Second day (or subsequent day): upper GI (UGI) series
Barium studies should be scheduled after the following procedures:
Abdominal or pelvic ultrasound examination
Lumbar-sacral spine x-rays
Pelvic x-rays
Hysterosalpingogram
IVP
As a general rule, examinations that do not require contrast should precede examinations that do require contrast. All examinations that require contrast agents should be completed before those that require barium contrast. In addition, examinations that require contrast agents must precede nuclear medicine examinations that require radioactive iodine administrations (e.g., thyroid scans). Other x-ray
examinations that do not require preparation can be performed at any time. Such examinations include the following:
examinations that do not require preparation can be performed at any time. Such examinations include the following:
X-rays of the head, spine, and extremities
Noncontrast abdominal x-rays (e.g., kidney, ureters, bladder [KUB], abdomen series)
Mammograms
CLINICAL ALERTNursing home patients should be accompanied by another adult to the x-ray testing site. If a nonfasting patient will be in the x-ray department over lunchtime, the facility should send a bag lunch or money for lunch with the patient.
PLAIN CONVENTIONAL X-RAYS/RADIOGRAPHY
Chest X-RayThe chest x-ray is the most frequently requested radiograph. It is used to diagnose cancer, tuberculosis and other pulmonary diseases, and disorders of the mediastinum and bony thorax. The chest x-ray provides a record of the sequential progress or development of a disease. It can also provide valuable information about the condition of the heart, lungs, GI tract, and thyroid gland. A chest x-ray must be done after the insertion of chest tubes or subclavian catheters to determine their anatomic position as well as to detect possible pneumothorax related to the insertion procedure. A postbronchoscopy chest x-ray is done to ensure there is no pneumothorax following a biopsy.
Reference Values
Normal
Normal-appearing and normally positioned chest, bony thorax (all bones present, aligned, symmetrical, and normally shaped), soft tissues, mediastinum, lungs, pleura, heart, and aortic arch
Procedure
Remember that routine chest radiography consists of two images: a frontal view (posteroanterior [PA]) and a left lateral view. Upright chest radiographs (digital images) are preferred and are of utmost importance because images taken in the supine position do not demonstrate fluid levels. This observation is especially important when testing patients on bed rest.
Street clothing that is covering the chest is removed to the waist. Allow only cloth or paper hospital gowns free of buttons and snaps to be worn during the x-ray. Remove jewelry on or adjacent to the chest.
Ensure that monitoring cables and patches do not obscure the chest area, if possible.
Instruct the patient to take a deep breath and to exhale; then to take another deep breath and to hold it while the x-ray image is taken. After the x-ray is completed, the patient may breathe normally.
The actual procedure takes only a few minutes.
Follow guidelines in Chapter 1 regarding safe, effective, informed intratest care.
Clinical Implications
Abnormal chest x-ray results may indicate the following lung conditions:
Presence of foreign bodies
Aplasia
Hypoplasia
Cysts
Lobar pneumonia
Bronchopneumonia
Aspiration pneumonia
Viral pneumonia
Lung abscess
Middle lobe syndrome
Pneumothorax
Pleural effusion
Atelectasis
Pneumonitis
Congenital pulmonary cysts
Pulmonary tuberculosis
Sarcoidosis
Pneumoconiosis (e.g., asbestosis)
Coccidioidomycosis
Abnormal conditions of the bony thorax include the following:
Scoliosis
Hemivertebrae
Kyphosis
Trauma
Bone destruction or degeneration
Osteoarthritis
Osteomyelitis
Cardiac enlargement
Interfering Factors
An important consideration in interpreting chest radiographs is to ask whether the film was taken in full inspiration. Certain disease states do not allow the patient to inhale fully. The following conditions may alter the patient’s ability to breathe properly and should be considered when evaluating radiographs:
Obesity
Severe pain
Congestive heart failure
Scarring of lung tissues
Interventions
Pretest Patient Care
No special preparation is required. However, the patient should be given a brief explanation of the purpose of and procedure for the test and assured that there will be no discomfort. Screen for pregnancy status of female patients. If positive, advise the radiology department.
Remove all jewelry and other ornamentation in the chest area before the x-ray.
Remind the patient of the need to remain motionless and to follow all breathing instructions during the procedure.
Follow guidelines in Chapter 1 regarding safe, effective, informed pretest care.
CLINICAL ALERTA portable x-ray machine may be brought to the nursing unit if the patient cannot be transported. The nurse may need to assist x-ray personnel in positioning the patient and image receptor (IR). It is the x-ray technologist’s responsibility to clear all unnecessary personnel from the radiation field before x-ray exposure.
Posttest Patient Care
Interpret test outcomes and monitor for pulmonary disease and chest disorders. Explain changes in therapy based on chest x-ray results (e.g., diuretics for pulmonary edema, endotracheal tube repositioning, starting or stopping mechanical ventilation), although the attending physician will ultimately make all decisions in the treatment plan.
Follow guidelines in Chapter 1 regarding safe, effective, informed posttest care.
Mammography (Breast X-Ray)Soft tissue mammography visualizes the breast to detect small abnormalities that could suggest a malignancy or benign disease. Its primary use is to screen for and discover cancers that escape detection by other means such as palpation. Typically, lesions <1 cm cannot be detected by routine clinical or self-examinations. Although the average breast cancer has probably been present for some time before it reaches the clinically palpable 1-cm size, the prognosis for cure is excellent if detected in this preclinical or presymptomatic phase.
The low-energy x-ray beam used for this procedure is applied to a tightly restricted area and consequently does not produce significant radiation exposure to other areas of the body. Therefore, it is quite acceptable from a radiation safety standpoint to recommend routine screenings. Diagnosis by mammography is based on the radiographic appearance of gross anatomic structures. Benign lesions tend to push breast tissue aside as they expand, whereas malignant lesions may invade surrounding breast tissue. Although false-negative and false-positive readings can occur, mammography is highly accurate.
Most breast lumps are not malignant; many are benign cysts. For women >40 years of age, the benefits of using low-dose mammography to find early, curable cancers outweigh possible risks from radiation exposure (Table 10.6).
The American College of Radiology (ACR) accredits mammography machines, and the U.S. Food and Drug Administration (FDA) certifies mammographic facilities. To earn accreditation, mammograms must be performed by specially trained and credentialed radiographers, and the resulting images must be interpreted by radiologists who meet criteria for continuing education in mammography. Additionally, the ACR has stringent standards for equipment, image quality, and radiation dose. Health insurers, including Medicare, require mammographic services to be performed at an accredited institution. The FDA has approved certain digital systems to record breast anatomy electronically— that is, on a computer, rather than on film.
Indications for Mammography
To detect clinically nonpalpable breast cancer in women >40 years of age, younger women at high risk, or those with a history of breast cancer
When signs and symptoms of breast cancer are present
Skin changes (e.g., “orange peel” skin associated with inflammatory-type cancer)
Nipple or skin retraction
Nipple discharge or erosion
Breast pain
TABLE 10.6 Likelihood of Breast Cancer
Age (yr)
Odds
30-39
1 in 233
40-49
1 in 69
50-59
1 in 38
60-69
1 in 27
Source: National Cancer Institute, 2006.
“Lumpy” breast; multiple masses or nodules
Pendulous breasts that is difficult to examine
Survey of opposite breast after mastectomy
Patients at risk for having breast cancer (e.g., family history of breast cancer)
Adenocarcinoma of undetermined origin
Previous breast biopsy
Tissue samples removed from the breast may be imaged using detailed mammography techniques
Follow-up studies for questionable mammographic images
NOTE
The American Cancer Society recommends annual mammography for all women at 40 years of age. (Smith RA, Brooks D, Cokkinides V, et al: Cancer screening in the United States 2013: A review of current American Cancer Society Guidelines, current issues in cancer screening, new guidance on cervical cancer screening and lung cancer screening. CA Cancer J for Clin 63(2):87-105, 2013.)
Reference Values
Normal
Essentially normal breast tissue: calcification, if present, should be evenly distributed; normal ducts with gradual narrowing ductal system branches
Procedure
Mammogram
Perform mammograms with the person in an upright position, preferably standing. Make accommodations for patients using wheelchairs.
Expose the breast. Elevate the inframammary fold to its maximum height. Lift onto a cassette or digital plate to the level of the inferior surface of the patient’s breast. Adjust the breast tissue by hand, smoothing out all skin folds and wrinkles. Lower a movable paddle onto the breast, rigorously compressing the breast tissue.
Make an x-ray exposure quickly and immediately lift the compression.
Typically, take two views (craniocaudal [CC] and mediolateral oblique [MLO]) of each breast.
Before or after the x-ray examination, the technologist visually observes and manually palpates the breasts.
Tell patient that the complete examination takes about 30 minutes.
Follow guidelines in Chapter 1 regarding safe, effective, informed intratest care.
X-ray-guided biopsy (stereotactic technique)
Administer a local anesthetic.
Have the patient lie on her abdomen, allowing her breast to protrude through an opening in a special table.
Take two stereo-view mammograms, allowing precise positioning of the biopsy needle.
Insert the needle into the breast at precise locations using sterile lacerations. Take multiple core tissue samples because tumors have both benign and malignant areas. In vacuumassisted biopsy procedure, a probe is inserted directly into the suspicious area, and tissue is gently vacuumed out for subsequent analysis. See Chart 10.1 for comparison of these two methods.
Cleanse the breast and apply a sterile dressing.
Needle x-ray localization and surgical biopsy
Administer a local anesthetic.
Insert a needle that holds a fine wire, clip, or biodegradable marker into the breast tissue, using stereotactic or sonographic guidance. When the needle point is at the tip of the lesion, the device is released. It stays there until the surgeon, guided by the wire, removes a specimen of the abnormal tissue.
NOTE
Rigorous compression is a brief and uncomfortable but critical step in ensuring a high-quality mammogram. It lowers dose and improves image quality.
CLINICAL ALERT
Computer software (computer-assisted diagnosis [CAD]) scans the image and notes suspicious areas that a radiologist could miss, thus acting as a second opinion.
Many radiologists double-read all mammograms.
Comparison with old mammograms is very important. Consequently, patients are advised to have all mammograms performed at the same facility or retrieve old mammograms and bring them along when having a new study performed.
Mammographic examination of augmented breasts requires additional views that add to procedure time. The presence of implants should be communicated to the radiology department when scheduling the procedure.
Clinical Implications
Abnormal mammogram findings reveal the following conditions:
Breast mass
Benign breast masses (e.g., cysts, fibroadenomas) are usually round and well demarcated.
Malignant breast masses are often irregularly shaped with extensions into adjacent tissue, generally with an increased number of blood vessels (Fig. 10.1).
When a mass is detected, additional studies are performed to help differentiate the nature of the mass. These studies may include the following:
Special x-ray magnification views of the area in question
Spot compression views performed using a special paddle that isolates the suspicious tissue (Fig. 10.2)
Ultrasound of the area to help differentiate a cystic (fluid-filled) mass from a solid lesion
Calcifications present in the malignant mass (duct carcinoma) or in adjacent tissue (lobular carcinoma) are described as innumerable punctuate calcifications resembling fine grains of salt or rodlike calcifications that appear thin, branching, and curvilinear. Macrocalcifications (large mineral
deposits) generally represent benign degenerative processes. Microcalcifications (<1/50 inch) are of more concern and require close examination.
FIGURE 10.1. Half of all breast cancers develop in the upper outer section. (Courtesy of Department of Health and Human Services, 1994.)
The likelihood of malignancy increases with a greater number of calcifications in a cluster. However, a cluster with as few as three calcifications, particularly if they are irregular in shape or size, can occur in cancer.
Typical parenchymal patterns are as follows:
N1: normal
P1: mild duct prominence on less than one fourth of the breast
P2: marked duct prominence
DY: dysplasia (some diagnosticians believe that the person who exhibits dysplasia is 22 times more likely to develop breast cancer than the person with normal results)
Findings of breast cancer when contrast is injected are associated with extravasation of contrast, filling defects, obstruction, or irregular narrowing of ducts (Chart 10.2).
CHART 10.1 Comparisons of Core Needle and Vacuum-Assisted Biopsy
Core Needle Biopsy | Technique | Disadvantages | Advantages |
ABB1 Site-select Centrica | Automated gun Large core needle | Requires multiple passes into tissue | Excellent for dense lesions Relatively inexpensive equipment |
Vacuum-Assisted Biopsy (VAB) | |||
M1BB Mammotome ATEC | Dual lumen needle/probe with rotating cutter | Increased potential for postprocedural bleeding Expensive equipment | Single pass into tissue yields multiple samples Larger tissue sample |
Interventions
Pretest Patient Care
Explain the purpose, procedure, benefits, and risks of mammograms. Mammography is the single best method for detecting breast cancer while it is still in a curable stage (Fig. 10.3). Some discomfort is to be expected when the breast is compressed.
Assess pregnancy status of female patients. If positive, advise radiology department.
Instruct the patient not to apply deodorant, perfume, powders, or ointment to the underarm area on the day of the examination. Residue from these preparations can obscure optimal visualization.
Advise the patient to wear separates rather than a dress because clothing must be removed from the upper body.
Suggest that patients who have painful breasts refrain from caffeinated foods and beverages (e.g., coffee, tea, cola, chocolate, some over-the-counter medications, and most antiasthmatic medication) for 2 to 4 weeks before testing.
Follow guidelines in Chapter 1 regarding safe, effective, informed pretest care.
NOTE
Patients in the reproductive age group are advised to have mammograms performed in the 2 weeks that follow their last menstrual period.
 FIGURE 10.2. Examples of whole breast compression (A) and spot compression (B). |
CHART 10.2 Clinical Note
Contrast mammography (ductogram, galactogram) is a valuable aid for diagnosing intraductal papillomas. Mammary duct injection is used when cytologic examination of breast fluid or discharge is abnormal. In contrast mammography, after careful cannulation of a discharging duct, about 1 mL of a radiopaque substance (e.g., 50% sodium diatrizoate) is injected into the breast duct with a blunt, 25-gauge needle.
Ductal lavage is a technique in which the milk ducts are cannulated. Saline is injected and, when withdrawn, will “wash out” ductal cells. These cells are examined in the laboratory, in much the same way as a Pap test is reviewed. (See Chapter 11 for additional information.)
 FIGURE 10.3. Approximate size of tumors found by mammography compared to commonly used coins. (Reprinted with permission of Susan G. Komen®. All images are copyrighted. © 2013, Susan G. Komen®. Adapted from Item No. KOMEED007100 Mammography Card 5/13.) |
Posttest Patient Care
Interpret test outcomes and counsel appropriately. If a biopsy is necessary, see procedures for biopsy using x-ray technology.
Follow guidelines in Chapter 1 regarding safe, effective, informed posttest care.
CLINICAL ALERT
A mammogram detects abnormalities that could warn of cancer. The actual diagnosis of cancer is made by biopsy. Only one in five biopsies tests positive for cancer.
Several methods can be used to provide a breast tissue sample necessary for cancer diagnosis. These include core needle biopsy, surgical biopsy, and vacuum-assisted biopsy. Any of these methods can utilize either x-ray mammography or ultrasound for image guidance.
Orthopedic X-Ray: Bones, Joints, and Supporting StructuresOrthopedic radiography examines a particular bone, group of bones, or joint. The bony or osseous system presents five functions of radiologic significance: structure support of the body, locomotion,
red marrow storage, calcium storage, and protection of underlying soft tissue and organ structures. Orthopedic radiography is performed on the following structures:
red marrow storage, calcium storage, and protection of underlying soft tissue and organ structures. Orthopedic radiography is performed on the following structures:
The extremities (e.g., hand, wrist, shoulder, foot, knee, hip)
The bony thorax (e.g., ribs, sternum, clavicle)
The spine (e.g. cervical, thoracic, lumbar, sacrum, coccyx)
The head and skull (e.g. facial bones, mastoids, sinuses)
Optimal results from orthopedic x-ray examinations depend on proper immobilization of the area being studied. To produce a thorough image of the body part, at least two projections are required. These are taken at angles of 90° to one another (e.g. anteroposterior and lateral views).
To examine more complex structures such as the spine and skull, or to examine a structure in greater detail, several projections from various angles may be required.
Reference Values
Normal
Normal osseous (bone) and supporting tissue structures
Procedure
Inform the patient that dietary restrictions are not necessary.
Have the patient assume the positions most favorable to capturing the best images. However, the degree of patient mobility and physical condition may also need to be considered. Typically, the anatomic structures being studied are examined from several angles and positions. This may require the technologist to manipulate the body area physically into a position that will allow optimal visualization.
Jewelry, zippers, snaps, monitoring cables, and so forth interfere with proper visualization. These objects must be removed from the visual field if possible. Skull x-rays require removal of dentures and partials.
Removal of any surgical-type hardware used to stabilize a traumatized area should be done only under the direction of the attending physician.
Follow guidelines in Chapter 1 regarding safe, effective, informed intratest care.
Clinical Implications
Abnormal orthopedic x-ray results may reveal the following conditions:
Fractures
Dislocations
Arthritis
Osteoporosis
Osteomyelitis
Degenerative joint disease
Hydrocephalus
Sarcoma
Abscess and aseptic necrosis
Paget’s disease (excessive formation and breakdown of bone tissue)
Gout
Acromegaly (excess growth hormone leading to severe disfigurement)
Metastatic processes
Myeloma
Osteochondrosis, for example,
Legg-Calvé-Perthes disease (excessive loss and growth of bone in the hip joint)
Osgood-Schlatter disease (irritation of the knee joint)
Bone infarcts
Bone tumors (benign and malignant)
Foreign bodies
Interfering Factors
Images of the lumbosacral spine, coccyx, or pelvis must be completed before barium studies because residual barium may interfere with proper visualization. Jewelry and accessories, heavy clothing, metallic objects, zippers, buttons, snaps, cables, and monitoring equipment and supplies can interfere with optimal views and need to be removed before the examination.
Interventions
Pretest Patient Care
Explain the purpose and procedure of the test. No preparation or dietary restrictions are necessary. Screen for pregnancy status of female patients. If positive, advise the radiology department.
Assure the patient that the procedure in and of itself causes no pain. However, necessary manipulation of the body may cause discomfort. If appropriate, pain medication may be administered before the procedure.
Advise the patient that all dentures, partials, jewelry, and other ornamentation worn in the anatomic area being examined must be removed before the study. If possible, simple clothing should be worn, and the previously mentioned items should be left at home or in the patient’s room.
Emphasize the importance of not moving during the procedure unless specifically instructed otherwise. Movement distorts or “blurs” the image and often requires repeat exposures.
Follow guidelines in Chapter 1 regarding safe, effective, informed pretest care.
Posttest Patient Care
Advise the patient to monitor for fractures, dislocations, and other orthopedic disorders. Counsel the patient about need for follow-up procedures and treatment.
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