Mosby Simulated Examination Three Flashcards
A pt’s blood pressure is measured as 140/70. The number 140 represents:
the pressure within the arterial vessels during contraction of the heart.
The use of water as an oral contrast material for CT of the abdomen and/or pelvis has several potential advantages, including (Pick 1 or more)
1. Increased palatability & improved pt comfort.
2. Better demonstration of enhancing bowel wall.
3. No interference with 3-D applications.
1, 2, and 3.
A(n) __________ contrast material may be described as one that does not dissociate into charged particles.
A. Neutral.
B. Non-ionic.
C. Osmolar.
D. Ionic.
B. Non-ionic.
Proper immobilization during a CT procedure may involve the use of:
1. soft-hook-and-loop (e.g. Velctro) immobilization straps.
2. adhesive medical tape.
3. good patient communication.
1 and 3 only.
The normal range of GFR for men is:
70 +/- 14 mL/min/m^2
Risk factors for contrast-induced nephrotoxicity (CIN) include:
1. diabetes.
2. advanced age.
3. hematuria.
1 and 2 only.
The reduction in number of infectious organisms without a complete elimination is termed:
A. medical asepsis.
B. sterilization.
C. surgical asepsis.
D. immunization.
A. medical asepsis.
Which of the following is the preferred range for pt heart rate for optimal cardiac CT studies?
A. 65-75 bpm.
B. 75-85 bpm.
C. 85-95 bpm.
D. > 100 bpm.
A. 65-75 bpm.
Urticaria is which of the following?
A. severe nausea with associated vomiting.
B. UTI.
C. Hives.
D. Bronchospasm.
C. Hives.
Which of the following type(s) of oral contrast material could cause peritonitis if leakage from the digestive tract occurs from perforation?
A. Iopamidol (Gastrografin).
B. Barium sulfate.
C. Diatrizoate (Hypaque).
D. Effervescent granules.
B. Barium Sulfate.
Which of the following is NOT an advantage of an automatic power injector over the manual bolus method of IV contrast administration?
A. uniform contrast enhancement throughout the examination.
B. consistent contrast agent administration for all pts.
C. decreased risk of contrast-induced neprhotoxicity (CIN).
D. shorter injection time.
C. Decreased risk of contrast-induced neprhotoxicity (CIN).
Which of the following is/are SEVERE reaction(s) to iodinated IV contrast?
1. Anaphylaxis.
2. Urticaria.
3. Vomiting.
1 only.
Which of the following lab values is the MOST dependable measure of renal function?
A. BUN.
B. Creatine.
C. PT.
D. PTT.
B. Creatine.
Which of the following angiocatheter sizes may be safely used for the automated power injection of iodinated contrast agent at flow rates higher than 3 mL/sec?
1. 18-gauge.
2. 20-gauage.
3. 22-gauage.
1 and 2 only.
Which of the following portions of the electrocardiogram (ECG) corresponds to the period of atrial systole?
A. P wave.
B. QRS complex.
C. Alpha wave.
D. T wave. E
A. P wave.
Which of the following terms is used to describe the IV injection of medication or contrast agent in one complete dose over a short time?
A. Infusion.
B. Bolus.
C. IV drip.
D. Infus-A-port.
B. Bolus.
Used in determining the biologic effect of iodinated contrast media, the term __________ refers to the number of ions formed when a substance dissociates in a solution.
Osmolality.
The injection rate of an automatic injector is set at 1.5 mL/sec. What is the injection time for a contrast agent volume of 150 mL?
A. 60 seconds.
B. 90 seconds.
C. 100 seconds.
D. 120 seconds.
100 seconds (150 divided 1.5 = 100).
Which of the following must be included when one is obtaining informed consent for an invasive procedure?
1. explanation of the examination techniques.
2. the possible risks & benefits of the examination.
3. alternatives to the procedure involved.
1, 2, and 3.
Which of the following may be considered a low-osmolar contrast medium?
1. Iothalamate meglumine.
2. Diatrizoate sodium.
3. Iohexol.
3 only.
examples of LOCM are:
Iohexol (Omnipaque)
Iopamidol (Isovue).
Ioversol (Optiray).
After the intrathecal injection of iodinated contrast agent for a post-myelography CT study of the lumbar spine, the pt should be instructed to:
A. take a cleansing enema.
B. Resume normal activity.
C. Rest for 8-24 hours with the head slightly elevated.
D. Rest for 8-24 hours in the Trendelenburg position.
C.
Which of the following pharmaceuticals may be administered before a cardiac CT procedure in an effort to improve visualization of the coronary vessels? (Pick 1 or more)
1. B-blocker.
2. Nitroglycerin.
3. Metformin.
1 and 2 only.
During CT examination of the chest & abdomen the highly radiosensitive breast tissue can be protected with minimal image artifact with the use of specialized shielding composed of:
A. Barium.
B. Aluminum.
C. Lead.
D. Bismuth.
D. Bismuth.
As part of a comprehensive approach to minimize CT radiation exposure to the pediatric pt, the technologist should: (Pick 1 or more)
1. precisely limit the acquisition to the indicated anatomical area.
2. refuse to perform unnecessary CT examinations.
3. reduce the technical parameters (e.g., mA, kVp) based upon the body habitus.
1 and 3 only.
AN x-ray photon may lose some of its energy in an interaction with an outer-shell electron of a target atom within the pt in the interaction known as:
Compton scatter.
Which of the following may be used to calculate DLP of a CT acquisition? (Pick 1 or more)
1. DLP = slice width (cm) x pitch.
2. DLP = MSAD x slice width (cm) x # slices in scan volume.
3. DLP = CTDIvol x scan length (cm)
2 and 3 only.
If all other technical factors remain constant, which of the following would serve to decrease pt radiation dose during a helical single-slice CT (SSCT) examination?
A. decreased SFOV.
B. decreased filtration.
C. Increased pitch.
D. Increased matrix size.
C. increased pitch.
ECG-gated tube current modulation may effectively reduce pt radiation dose during which of the following procedures?
A. CT colonography.
B. Brain perfusion CT.
C. CT urogram.
D. Cardiac CT.
D. Cardiac CT.
Which of the following radiation dose indices is a measure of the total radiation exposure for an entire series of CT images?
A. CTDI100.
B. DLP.
C. CTDIvol.
D. MSAD.
B. DLP.
What measures the dose to each slice along a helically acquired volume?
CTDIvol.
Effective dose is a relative radiation dose measurement term that accounts for the:
A. beam pitch.
B. tissue radiosensitivity.
C. detector pitch.
D. collimation.
B. Tissue radiosensitivity.
The dose modulation capabilities of a CT scanner may include automatic control of: (Pick 1 or more).
1. tube current (milliamperage).
2. tube potential (applied kilovoltage).
3. focus-to-isocenter distance (cms).
1 and 2 only.
What is Uriticaria?
Hives.
Which lab value is most dependable measurement of renal function?
A. BUN.
B. Creatinine.
C. PT.
D. PTT.
B. Creatinine.
Which is true regarding the relationship b/t MSAD and image spacing during axial (step & shoot) scanning?
A. MSAD decreases with overlapping scans.
B. MSAD increases with overlapping scans.
C. MSAD increases with noncontiguous scans.
D. MSAD equals the product of image spacing & pitch.
B. MSAD increases with overlapping scans.
Dosimetry index used to approximate the radiation dose for CT sections acquired during a helical scan is called:
A. CTDIw.
B. Effective dose.
C. CTDIvol.
D. Equivalent dose.
C. CTDIvol.
Which technique may be employed to reduce pt radiation dose during cardiac CT exams?
C. Prospective ECG gating.
Compared to SSCT, pt radiation dose during MDCT may be higher because of: (Pick 1 or more)
1. use of cone beam radiation.
2. acquisitions at thinner section widths.
3. higher-powered x-ray tubes.
1 and 2 only.
__________ benign, highly vascular mass commonly found in the liver.
Hemangioma.
Which is the preferred contrast enhancement phase for CT of the spleen?
A. pre-contrast phase.
B. equilibrium phase.
C. arterial phase.
D. portal venous phase.
D. Portal venous phase.
Which describes the appearance of an acute subdural hematoma on a CT brain?
A. radiolucent.
B. hyperdense.
C. hypodense.
D. isodense.
B. Hyperdense.
Benign mass of the 8th cranial nerve known as vestibular schwannoma may also be referred to as:
Acoustic neuroma.
The thick layered portion of the peritoneum that is responsible for attaching portions of the intestines to the bowel well is called the:
Mesentery.
After initiation of bolus contrast, the nephrographic phase of renal contrast enhancement occurs at:
70-90 sec
Which of the following dosages would be sufficient to opacify the rectosigmoid region?
A. 150-250 mL.
B. 300-500 mL.
C. 500-750 mL.
D. 900 - 1100 mL.
A. 150-250 mL.
Late effects of radiation, such as genetic mutations, may occur with even small doses of radiation & are termed:
A. stochastic.
B. somatic.
C. non-stochastic.
D. chronic.
A. stochastic.
Assuming no other technical changes are made, which of the following adjustments would result in DECREASED radiation dose to the pt for a given CT acquisition? (Pick 1 or more)
1. eliminate a clinically unnecessary contrast phase acquisition.
2. increase the tolerated noise level of scan.
3. increase kVp from 100 to 140.
4. increase pitch from 1.0 to 1.5.
5. decrease the scan length along the z-axis.
1, 2, 4 and 5.
Which of the following statements is true regarding the relationship b/t MSAD and image spacing during axial (step-and-shoot) scanning?
A. MSAD decreases with overlapping scans.
B. MSAD increases with overlapping scans.
C. MSAD increases with noncontiguous scans.
D. MSAD equals the product of image spacing & pitch.
B. MSAD increases with overlapping scans.
The dosimetry index used to approximate the radiation dose for CT sections acquired during a helical scan is called the:
CTDIvol.
Which of the following techniques may be employed to reduce pt radiation dose during a cardiac CT examination?
A. retrospective electrocardiogram (ECG) gating.
B. z-axis interploation.
C. prospective ECG gating.
D. multisegment reconstruction.
C. Prospective ECG gating.
Which of the following reconstruction methods may be employed by a CT system for the purpose of reducing patient radiation dose?
A. Convolution reconstruction.
B. Interpolation reconstruction.
C. Back-projection reconstruction.
D. Iterative reconstruction.
D. Iterative Reconstruction.
The DLP is identical for a given CT scan acquired on two patients, each with a significantly different body habitus. What happens to absorbed dose?
The absorbed dose is greater in the pt with a smaller body habitus.
Compared with SSCT, pt radiation dose during a MSCT study may be higher because of:
1. use of a cone beam of radiation.
2. Acquisitions at thinner section widths.
3. Higher-powered x-ray tubes.
1 and 2 only.
Model-based iterative reconstruction (MBIR) considers:
The shape of the x-ray beam before (pre-) and after (post-) the patient.
The reduction in intensity of an x-ray beam as it interacts with matter is called:
Attenuation.
A _____ is a benign, highly vascular mass commonly found in the liver.
Hemangioma.
Which of the following is the preferred contrast enhancement phase for CT acquisition of the spleen?
A. precontrast phase.
B. equilibrium phase.
C. arterial phase.
D. portal venous phase.
D. Portal venous phase.
During a PET-CT examination, the amount of fludeoxyglucose F 18 (FDG) uptake in an anatomic region is directly proportional to the area’s:
Metabolic activity.
The benign mass of the 8th cranial nerve known as a vestibular schwannoma may also be termed a(n):
Acoustic Neuroma.
The nephrographic phase of renal contrast enhancement occurs at approximately:
70-90 seconds.
Which of the following is a common complication of CT-guided biopsy of the lung?
A. PE.
B. aspiration.
C. Pneumoconiosis.
D. Pneumothorax.
D. Pneumothorax.
What MDCT examination may include endobrachial views?
Virtual bronchoscopy.
During HRCT of the lungs, edematous changes in the posterior lungs may be differentiated by positioning the pt in the _____ position.
Prone.
The firm, outer portion of each intervertebral disc is called the:
Anulus fibrosus.
During which of the following IV contrast phases does the bladder wall enhance?
A. early arterial.
B. corticomedullary.
C. nephrographic.
D. excretory.
C. nephrographic.
The best method for targeting the sacrum in a pelvis CT for detailed examination would be to:
retrospectively reconstruct the image using a small DFOV.
The epithelial lining of the urinary tract is called the:
Urothelium.
The primary drainage opening within the sinus cavities, which is a common area for inflammation, is referred to as the:
Ostiomeatal complex.
The overall quality of MPR and VR 3-D images from a carotid artery CTA may be improved by:
- reducing the kVp for an increased in displayed vessel opacification & contrast.
- Retrospective reconstruction with a 50% overlap in section increment.
- bolus tracking software to maximize contrast enhancement.
Which of the following is the most common sign of GI pathology on CT images?
A. fluid collection.
B. wall thickening.
C. air distention.
D. dense fecal matter.
B. wall thickening.
Arterial phase CT imaging of the liver is used to optimally demonstrate which of the following?
A. fatty infiltration.
B. hepatic cysts.
C. portal vein thrombosis.
D. hepatocellular carcinoma (HCC).
D. Hepatocellular carcinoma (HCC).
A quality control procedure determines that the low-contrast resolution of a CT scanner is extremely poor. Likely causes are:
1. tube arcing.
2. increased electronic noise.
3. decreased tube output.
2 and 3 only.
Which of the following statements about collimation of the CT xray beam is false?
a. collimation of the xray beam occurs both before and after the patient.
b. collimation of the beam occurs in the z-axis, thus affecting slice thickness.
c. increases in collimation increases the intensity of the primary beam.
d. collimation of the CT xray beam is used to limit the detection of scatter radiation.
c.
- b/c increasing collimation = decreases the intensity of the primary beam.
What term may be used to describe the quantity of radiation emitted from the CT x-ray tube toward the patient?
Photon fluence.
A PACS is connected with imaging modalities and other peripheral devices on a computerized communications system called a:
Network.
The major disadvantage of the back-projection method of image reconstruction is the appearance of the:
Star artifact.
The process of grayscale mapping of the CT image may be referred to as:
Windowing.
In the formula used to calculate the linear attenuation coefficient, I=Ioe ^-ux the symbol I0 identifies the:
Incident intensity.
The intensity of the xray beam after it passes through an object to a detector is called the:
Transmitted intensity.
A high-resolution comb is utilized by a multidetector CT (MDCT) detector array in an effort to reduce:
Scatter radiation.
The distance between the centers of two adjacent reconstructed CT images is termed the:
Section interval.
The maximum number of simultaneous sections a MDCT system can acquire per gantry rotation is controlled by the number of:
Data channels.
Matrix size describes:
Number of pixels used to display image.
The implementation of corrective actions to improve any identified performance inadequacies of the CT system is referred to as:
Quality control.
When choosing a SFOV, the ct technologist is controlling the:
- diameter of data acquisition.
- number of activated detectors within the array.
- correction factors for the specified area of anatomic interest.
The geometric efficiency of a CT detector is influenced primarily by the:
amount of interspace material between detectors.
The Feldkamp-Davis-Kress (FDK) algorithm may be applied to MDCT acquisition data to overcome image artifacts from;
Beam divergence.
MDCT systems are typically cable of differentiating adjacent objects with attenuation differences as small as:
3 HU.
The ability of MDCT system to freeze motion & provide an image free of blurring is called;
Temporal resolution.
The polyenergentic xray beam emitted from a CT xray tube is susceptible to artifacts resulting from the phenomenon known as:
Beam hardening.
In a MDCT what technical parameter determines the reconstructed section width?
Detector collimation.
What actions would serve to magnify the CT image on the display monitor?
Decrease display field of view.
The bit depth of a digital imaging system defines the number of information bits contained within each:
Pixel.
The technical factor(s) necessary for the acquisition of an isotropic data set is/are:
1. thin detector collimation.
2. high mA setting.
3. small DFOV
1 and 3 only.
In MDCT, the combined thickness of all of the sections simultaneously acquired within each gantry rotation are called the:
Total collimation.
Which is a manifestation of the partial volume artifact?
Cupping.
During volumetric CT acquisition, the slice sensitivity profile (SSP) graphically reprsents the;
Effective section width.
An increase in the sampling rate during CT data acquisition corresponds to an increase in:
views per rotation.
