Ch. 1 - Diagnostic Tests Pt. 1 Flashcards
The three most common contrast agents
Barium, iodine, and gadolinium-based contrast agents
Contrast media can be used with what tests?
Plain X-Rays, CT, and MRI studies
The five most common radionuclides include:
Radioactive iodine, technetium, thallium, gallium, and indium
Nuclear studies are useful in the imaging of what?
Bone imaging, and for determination of thyroid and hepatobiliary function
What can a variety of radionuclides be used to assess, due to their ability to image aspects of cardiac physiology, such as perfusion and ejection fraction?
Coronary artery disease
What procedure utilizes high-frequency sound waves to image soft tissue and produce an image?
Ultrasonography, and the image it produces is known as an ultrasound
Name up to five advantages of U.S. (Ultrasonography) over MRI and CT scanning
Its ability to differentiate solid from fluid-filled structures, lower cost, portability, accessibility, and no exposure to ionizing radiation
What are three limitations to ultrasonography?
The skill level of the ultrasonographer, lower quality of image resolution compared to other modalities, and “noise” produced when US waves hit gas and bone
What method of ultrasonography is useful in the evaluation of venous insufficiency, blood clots, arterial occlusion, or stenosis, and also for identifying valvular disorders and congenital defects?
Doppler ultrasonography
What scan is particularly useful for intracranial (i.e., brain), neck, abdominal, pelvic, and lung images, as well as for detection of pulmonary embolism, aortic aneurysm, aortic dissection, or acute hemorrhage?
CT scan - it can also be used to define the size, precise location, and extent of a tumor’s involvement with surrounding tissues
When is a patient unable to undergo a scan via MRI Machine due to the powerful magnet used?
Individuals with implanted metal, such as pacemakers, pins and plates, implanted defibrillators, cochlear implants, and those with artificial joints
When is MRI preferred to CT scanning?
When soft tissue resolution is needed. It is also particularly useful in imaging the spinal cord or spinal column, brain abnormalities, internal joint derangements, and trauma
What scans are used to evaluate pulmonary nodules to determine if they are metabolically active, and to evaluate lung cancer, colorectal cancer, esophageal cancer, head and neck cancer, lymphoma, and melanoma?
PET scans. Because its scan measures abnormal cellular activity, it is also a useful adjunct in the diagnosis of Alzheimer’s disease, Parkinson’s disease, epilepsy, and hibernating myocardium
PET scans can be used in conjunction with what other scan(s)/images to correlate structural abnormalities with function information?
CT or MRI images
Name six limitations of PET scanning
Cost, accessibility, the nature of the radionuclide agent, elevated serum glucose or insulin levels can adversely affect the results, limited sensitivity for defining tumors smaller than 10 mm, and the high degree of expertise required for proper interpretation
What imaging study is used to visualize the major blood vessels in the body, including those of the heart, carotids, brain, kidneys, lungs, and legs?
(Traditional) Angiography. When performed to image veins, it is a venogram. If arteries are visualized, it is an arteriogram. Note - traditional angiography is considered the gold standard for vessel imaging and is the study of choice when intervention is necessary
After injected, the contrast material creates an image of the inside of the vessel or lumen. This allows identification of what? (Multiple answers).
Obstruction (i.e., stenosis), aneurysms, arteriovenous malformations, pulmonary emboli, and deep vein thrombosis
What benefits do computer tomography angiography and magnetic resonance angiography provide when compared to traditional angiography?
They are less invasive, have less risk, and produce reasonably accurate images of arteries and veins
What has moved from being solely a diagnostic modality to having major surgical applications?
Endoscopy
Endoscopes are designed for specific purposes. What are examples of these purposes? (Multiple answers)
Colonoscopy, gastroscopy, duodenoscopy, laparoscopy, bronchoscopy, cystoscopy, colposcopy, proctoscopy/sigmoidoscopy, thoracoscopy, or arthroscopy
When the brain is involved, what tests are invaluable?
CT and/or MRI imaging
What imaging modality is particularly useful to define post-traumatic skull or facial fractures, and for identification of osseous changes, as seen in multiple myeloma and Paget’s disease?
X-Ray
What specialized test involves the insertion of a needle into the subarachnoid space between the 4th and 5th lumbar vertebrae to withdraw cerebrospinal fluid (CSF) for testing?
Spinal tap (Lumbar puncture). This can be useful for diagnosis of subarachnoid hemorrhage, infection/inflammation, multiple sclerosis, and Guillain-Barre syndrome
What specialized test evaluates syncope?
A tilt table test
Define ‘evoked potentials’
The measured electrical response of the brain to stimulation of specific sensory pathways
What evoked potentials are used in the diagnosis of multiple sclerosis?
Visual evoked potentials
What evoked response is an electrical response to a click or noise made in each ear, thus helping in the diagnosis of deafness, particularly in infants?
Brainstem auditory evoked response. The response is also delayed in multiple sclerosis
What test involves the intravenous injection of dye into an arm vein to image the retina and choroid vasculature of the eye?
Fluorescein angiography
Nodules that are noted on thyroid scans are classified as:
Cold (i.e., less uptake than normal thyroid tissue), functional (i.e., uptake like normal tissue), or hot (i.e., greater uptake than normal tissue)
Of the three nodule classifications (cold, functional, and hot), which nodules have an increased probability of malignancy and are usually referred for further testing?
Cold
What test utilizes a small dose of an iodine-based radionuclide agent to determine the function of the thyroid?
Radioactive iodine uptake (RAI)
What test is completed to determine whether a cold nodule seen on a scan is benign or malignant?
Fine needle aspirate (FNA). However, FNA cannot be used to diagnose follicular or Hurthle cell carcinomas because it cannot distinguish between adenomas and cancers
In cases where CT or MRI fail to provide a diagnosis for neuroblastomas or pheochromocytoma, what scan can be useful?
MIBG scan (i.e., meta-iodobenzylguanidine). PET scans are also useful in localizing pheochromocytomas that can develop outside the adrenals
Regarding chest pathology, what screening test is valuable due to their low cost and availability?
X-rays. They are useful for visualizing lung aeration, heart contours, mediastinal structures, calcifications, and the diaphragm
When pulmonary lesions are large, growing, or obstructing (i.e., causing pressure on bronchi or trachea) biopsy is usually necessary. What tests assist in creating the diagnosis?
Bronchoscopy, mediastinoscopy, or thoracoscopy
What imaging technique is the preferred choice to visualize the pulmonary vessels?
CT angiography
What tests record the movement of air into and out of the lungs and plot it against time?
Pulmonary function tests (PFTs)
What are the most common respiratory measurements seen in underwriting?
Forced vital capacity (FVC - maximum volume or air exhaled after deep inspiration), forced expiratory volume at 1 second (FEV1 - measurement made at 1 second after exhaling as hard and as fast as possible), FEV1/FVC ratio, and diffusing capacity (DLCO - measures the ability of inhaled carbon monoxide to move out of the lungs and into the blood. This gives important information about the gas exchanging capacity of the lungs)
FVC and FEV1 are compared to predicted values based on age and height and presented as a percentage. Above what value (percentage) is considered normal?
Above 80%. Low FEV1/FVC ratio is considered obstructive, while normal or high FEV1/FVC can indicate restrictive diseases
EEG, electro-oculogram, respiratory effort, airflow, oxygen saturation, electrocardiogram, body position, submental and anterior tibialis movements, noises (including snoring), are recorded during what test?
A sleep study
What test is considered a routine screening test for breast cancer, and recommended for females over age 40, and sometimes at younger ages when there’s a family history of breast cancer?
Mammography. It is the first diagnostic test done when a palpable mass is detected
What are the limitations to mammography?
Dense breast tissue, implants, and the skill of the radiologist. Mammography also misses up to 10-20% of clinically palpable breast cancers and does not detect inflammatory breast cancer. Therefore, if there is a clinically suspicious mass, further testing or biopsy is necessary
Stress testing is performed to test for what?
Coronary heart disease (e.g., ischemia, infarction). Different modalities include exercise EKG testing and pharmacologic, which uses drugs such as adenosine, regadenoson, and dobutamine to stress the heart
What test sends sound waves across the chest wall and when combined with Doppler studies, allow for painless assessment of chamber sizes, sizes of great vessels, valve structures, valve function, and pressures within the heart?
Echocardiograms
What monitor/test applies leads to the chest and provide continual or periodic EKG recordings for 24 hours or longer?
A Holter monitor
What is a long-term monitor for arrhythmias that can be used from months to years, and is typically used to detect events that are infrequent, or if other modalities have been inconclusive?
Cardiac monitors (i.e., implantable loop recorder)
What test is used extensively to image the liver, kidneys, gallbladder, common bile duct, pancreas, and to identify ascites?
Ultrasound
What is the most common technique for diagnosis of non-intestinal pathology and is often used to follow-up on abnormalities seen on ultrasound?
CT
What test is the gold standard for renal artery stenosis and renovascular hypertension?
Renal arteriography. However, these impairments are most often visualized via US, CTA, or MRA
What test is most useful for imaging bone and soft tissue abnormalities?
MRI. It has essentially replaced CT scanning, except for guided biopsies
What is the most common screening test for cervical cancer?
PAP test
Type of external cardiac monitoring that can be worn up to 30 days
Mobile outpatient cardiac telemetry (MOCT)
