Simulated Examination Three Flashcards
The use of water as an oral contrast material for CT of the abdomen and/or pelvis has several potential advantages, including:
1. Increased palatability and improved patient comfort
2. Better demonstration of enhancing bowel wall
3. No interference with 3-D applications
D. 1,2, and 3
- A patients blood pressure is measured as 140/70mm Hg. The number 140 represents:
a. The pressure within the arterial vessels during contraction of the heart
B. The pressure exerted on the chambers of the heart while relaxed
C. The pressure within the arterial vessels while the heart is relaxed
D. The pressure exerted on the chambers of the heart during a contraction
A. The pressure within the arterial vessels during contraction of the heart.
- A —— contrast material may be described as one that does not dissociate into charged particles in solution.
B. Nonionic
- Proper immobilization during a CT procedure may involve the use of.
I. Soft, hook-and - loop( eg, Velcro) immobilization straps
2: adhesive medical tape - Good pt communication
1 and 3 only.
- The normal GFR range for men is:
a. 50 -+14
b. 60+-10
c. 70+-14
d. 80+-10
C. 70+-14
- Risk factors for contrast - induced nephrotoxicity (CIN) incl:
1: Diabetes - Advanced age
- Hematuria
1 and 2 only.
- The reduction in number of infectious organisms with out 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 patient 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. Urinary tract infection
C. Hives
D. Bronchospasm
C. Hives
- Which oral contrast material could cause peritonitis if leaks from the digestive tract occurs from perforation.
A. iopamidol ( gastrografin)
B. Barium sulfate
C. Diatrizoate( hypaque)
D. Effervescent granules
B. Barium sulfate
- Which is NOT an advantage of an automatic power injector over the manual bolus method of IV contrast.
A. Uniform contrast enhancement throughout the examination
B. Consistent contrast agent administration for all pts
C. Decreased risk of contrast induced nephrotoxicity (CIN)
D. Shorter injection times
C. Decreased risk of contrast induced nephrotoxicity (CIN)
- Which are severe adverse reaction to iodinated intravenous contrast media.
- Anaphylaxis
- Urticaria
- Vomiting
A. 1 only.
- Which lab values is the most dependable measure of renal function.
A. Blood urea nitrogen ( BUN)
B. Creatinine
C. Prothrombin time (PT)
D. Partial thromboplastin time ( PTT)
B. Creatinine
Which angiocatheter sizes is safely used with auto power injections of contrast with flow rates of 3 and higher.
1. 18 gauge
2. 20 gauge
3. 22 gauge
1 and 2 only.
- Which portion of the ECG corresponds to atrial systole.
A. P wave
B. QRS complex
C. Alpha wave
D. T wave
A. P wave
- Which term is used to describe IV injection of medication or contrast in one complete dose over short period of 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 substance dissociates.
A. Solubility
B. Osmolality
C. Concentration
D. Iodination
B. Osmolality
- Injection rate of 1.5 mL is set for contrast volume of 150 mL. What is the injection time.
A. 60 seconds
B. 90 seconds
C. 100 seconds
D. 120 seconds
- hint: Divide the volume and the rate
C. 100 seconds
- Which must be incl when one is obtaining informed consent for an invasive procedure.
- Explanation of the examination techniques
- Possible risk and benefits
- Alternatives to the procedure involved
1,2 and 3
- Which may be considered low osmolar contrast medium.
- iothalamate meglumine
- Diatrzoate sodium
- iohexol
3 only.
- After intrathecal injection of iodinated contrast agent for a postmyelography CT study of lumbar spine. The pt should be instructed to.
A. Take a cleansing enema
B. Resume normal activity
C. Rest for 24 hrs with head slightly elevated
D. Rest for 8-24hrs in the trendelenburg position
C. Rest for 24hrs with head slightly elevated 35-45dgs
- Which pharmaceuticals may be administered before a cardiac CT procedure for visualization of coronary vessels.
- B-blockers
- Nitroglycerin
- Metformin
C. 1 and 2 only.
- During a CT of the chest and abdomen the highly radiosensitive breast tissue can be protected with minimal image artifact with the use of specialized shielding called.
A. Barium
B. Aluminum
C. Lead
D. Bismuth
D. Bismuth
- To minimize CT radiation exposure on a pediatric pt, the tech should.
- Precisely limit the acquisition to the indicated anatomical area
- Refuse to perform unnecessary CT examinations
- Reduce the technical parameters ( eg, mA, KVp) based upon 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:
A. Compton
B. Rayleigh scatter
C. Photoelectric absorption
D. Pair production
A. Compton
- Which is used to calculate the dose length product of CT acquisition:
- DLP= slice width(cm) x pitch
- DLP=MSADx slice width (cm)x # of slices in scan volume
- DLP=CTDIvol x scan length(cm)
2 and 3 only.
- If all other technical factors stay constant, which would serve to decrease pt dose during helical single slice CT (SST).
A. Decreased scan field of view
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:
A. CT colonography
B. Brain perfusion CT
C. CT urogram
D. Cardiac CT
D. Cardiac CT
- Which radiation dose indices is a measure of the total radiation exposure for an entire series of CT images:
A. CTDI100
B. Dose length product (DLP)
C. CTDIvol
D. Multiple scan average dose (MSAD)
B. Dose length product (DLP).
- 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.
- dose modulation capabilities of CT scanner may incl automatic control of:
- Tube current ( milliamperage)
- Tube potential ( applied kilovoltage)
- Focus-to - isocenter distance ( centimeters)
1 and 2 only.
Late affects of radiation, such as genetic mutations, may occur with even small doses of radiation and are termed:
A. Stochastic
B. Somatic
C. Nonstochastic
D. Chronic
A. Stochastic
- Assuming no other technical changes are made, which of the following adjustments would results in decreased radiation dose to the pt given CT acquisition.
- Eliminate a clinically unnecessary contrast phase acquisition
- Increase the noise level of scan
- Increase the tube potential (KVp) from 100 to 140
- Increase the pitch from 1.0 to 1.5
- Decrease the scan length along the z- axis
1, 2, 4, and 5 only.
- Which statements is true regarding the relationship between multiple scan average dose (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 and 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.
A. CTDIw
B. Effective dose
C. CTDIvol
D. Equivalent dose
C. CTDIvol
- Which techniques may be employed to reduce pt radiation dose during a cardiac CT exam.
A. Retrospective electrocardiogram (ECG) gating
B. Z - axis interpolation
C. Prospective ECG gating
D. Multi segment reconstruction
C. Prospective ECG gating
- Which reconstruction methods may be employed by a CT system for the purpose of reducing pt dose:
A. Convolution reconstruction
B. Interpolation reconstruction
C. Back projection reconstruction
D. Iterative reconstruction
D. Iterative reconstruction.
- The DLP is identical for what given CT scan acquired on two pts, each with a significant different body habitus. Which is correct:
A. The absorbed dose is identical in each pt
B. The absorbed dose is greater with the pt with larger body habitus
C. The absorbed dose is greater with the pt with smaller body habitus
D. Dose length product is unrelated to absorbed dose in the pt
C. The absorbed dose is greater with the pt with smaller body habitus.
- Compared with single - slice CT ( SSCT), pt radiation dose during a multidetector CT study may be higher because of:
- Use of cone beam of radiation
- Acquisition at thinner section widths
- Higher - powered x-ray tubes
1 and 2 only.
- Which will NOT reduce pt exposure during CT:
A. Increase mA from 180 to 360
B. Increase pitch from 1.0 to 1.5
C. Increase tolerated noise level index
D. Increase table speed from 32 to 48mm/sec
A. Increase mA from 180 to 360
- Model- based iterative reconstruction ( MBIR) considers which CT image formation:
A. The shape of x-ray beam before ( pre-) and after ( post -) the pt
B. A master image stored in the CT system’s computer
C. The detector configuration used for the acquisition
D. The age, gender, and weight of the scanned pt
A. The shape of the x-ray beam before ( pre-) and after (post-) the pt
- The reduction in intensity of an x-ray beam as it interacts with matter is called:
A. Scatter
B. Attenuation
C. Transmission
D. Luminescence
B. Attenuation
- A ——— is a benign, highly vascular mass commonly found in the liver:
A. Hematoid
B. Vasculoma
C. Hemogenic carcinoma
D. Hemangioma
D. 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 ( 60- 70sec ).
- Number 2 on figure 8.1 is:
A. Capitate
B. Lunate
C. Hamate
D. Scaphoid
D. Scaphoid
- The anatomical plane on fig 8.1 is:
A. Coronal plane
B. Sagittal plane
C. Axial plane
D. Oblique axial plane
A. Coronal plane
- Number 1 on the fig 8.1 is:
A. Capitate
B. Lunate
C. Hamate
D. Scaphoid
A. Capitate
- Number 5 on fig 8.1 is:
A. Capitate
B. Lunate
C. Hamate
D. Scaphoid
B. Lunate
- Which terms describes the appearance of an acute subdural hematoma on CT image of the brain:
A. Radiolucent
B. Hyperdense
C. Hypodense
D. Isodense
B. Hyperdense
- The angiographic assessment known as CT runoff evaluates the peripheral arterial tree from renal arteries through:
A. Aortic arch
B. Superior mesenteric artery
C. Aortic bifurcation
D. Distal lower extremity
D. Distal lower extremity
- During a PET-CT exam, the amount of fludeoxyglucose F18(FDG) uptake in an anatomic region is directly proportional to the areas:
A. Size
B. Central vs. peripheral location
C. Radiosensitivity
D. Metabolic activity
D. Metabolic activity
- Number 2 on the fig 8.2 is:
A. Left ovary
B. Bladder
C. Sigmoid colon
D. Uterus
A. Left ovary
- Number 4 on the fig 8.2 is:
A. Left ovary
B. Bladder
C. Sigmoid colon
D. Uterus
D. Uterus
- Number 5 on the fig 8.2 is:
A. Left ovary
B. Bladder
C. Sigmoid colon
D. Uterus
B. Bladder.
- Accurate demonstration of ——— would most likely require the intravenous injection of an iodinated contrast agent during a CT study of chest:
A. Pneumonia
B. Asbestos
C. A dissecting aortic aneurysm
D. A solitary pulmonary nodule
C. A dissecting aortic aneurysm.
- The benign mass of the eighth cranial nerve known as a vestibular schwannoma may also be termed:
A. Acoustic neuroma
B. Hypoglossal adenoma
C. Olfactory neuroblastoma
D. Optic nerve glioma
A. Acoustic neuroma.
- Number 3 on fig 8.3 is:
A. Cricoid cartilage
B. Piriform sinus
C. Aryepiglottic
D. Vocal cord
D. Vocal cord.
- Number 1 on fig 8.3 is:
A. Trachea
B. Piriform sinus
C. Aryepiglottic fold
D. Vocal cord
B. Piriform sinus
- Which window setting was most likely used to display the image in the figure:
A. WL -300, WW 1000
B. WL -50, WW 50
C. WL +50, WW 150
D. WL +400, WW 3000
A. WL -300, WW 1000
- Number 2 on fig 8.3 is:
A. Hyoid bone
B. Cricoid cartilage
C. Thyroid cartilage
D. Mandible
C. Thyroid cartilage.
- The thick, layered of the peritoneum responsible for attaching portions of the intestines to the bowel wall is called:
A. Gerota fascia
B. Falciform ligament
C. Mesentery
D. Ligamentum teres
C. Mesentery
- After initiation of rapid bolus administration of an iodinated contrast agent, the nephrographic phase of renal contrast enhancement occurs at approximately:
A. 20-25 sec
B. 30-40 sec
C. 70-90 sec
D. 3-5 min
C. 70-90 sec
- Number 9 on the fig 8.4 is:
A. Ethmoid sinus
B. Nasal concha
C. Maxillary sinus
D. Sphenoid sinus
C. Maxillary sinus.
- Number 5 on the fig 8.4 is:
A. Optic nerve
B. Superior ophthalmic vein
C. Oculomotor nerve
D. Superior oblique muscle
B. Superior ophthalmic vein
- Number 4 on the fig 8.4 is:
A. Superior rectus muscle
B. Superior ophthalmic vein
C. Levator palpebrae superioris muscle
D. Superior oblique muscle
D. Superior oblique muscle
- Number 6 on fig 8.4 is:
A. Optic nerve
B. Medial rectus muscle
C. lateral rectus muscle
D. Oculomotor nerve
C. Lateral rectus muscle.
- Which is a common complication of CT -guided biopsy of the lung:
A. Pulmonary embolism
B. Aspiration
C. Pneumoconiosis
D. Pneumothorax
D. Pneumothorax.
- Number 6 on fig 8.5 is:
A. Renal cortex
B. Renal pelvis
C. Renal calyx
D. Renal pyramid
C. Renal calyx
- Which reformation techniques best describes the image 8.5:
A. Volume rendering 3-D
B. MPR
C. Min- IP
D. MIP
D. MIP - maximum intensity projection.
- Number 1 on the fig 8.5 is:
A. Uteropelvic junction
B. Uterovesicle junction
C. Uterocalyceal junction
D. Uteropyramidal junction
D. Uteropelvic junction (UPJ).
- A common formula used to calculate the maximum dosage of I’ve contrast used in CT is:
A. 5 mg per keg of body weight
B. 5ml per Ib of body weight
C. 2 ml per kg of body weight
D. 1 ml per Ib of body weight
C. 2 mL per kg of body weight.
- Which MDCT exam may incl endobrachial views:
A. Virtual colonoscopy
B. High- resolution CT ( HRCT) of the lungs
C. Virtual bronchoscopy
D. Computed tomography angiogram ( CTA)
C. Virtual bronchoscopy.
- During HRCT of the lungs, edematus changes in posterior lungs may be differentiate by positioning of the pt in the:
A. Supine
B. Right lateral decubitus
C. Left lateral decubitus
D. Prone
D. Prone.
- The firm, outer portion of each intervertebral disc is called:
A. Nucleus pulposus
B. Nucleus prepositus
C. Anulus fibrosus
D. Anulus stapedius
C. Anulus fibrosus
- Number 2 on fig 8.6 is:
A. Superior facet
B. Pedicle
C. Transverse process
D. Lamina
C. Transverse process.
- Number 1 on fig 8.6 is:
A. Spinal root
B. Superior articular recess
C. anterior arch
D. Transverse foramen
D. Transverse foramen
- Number 4 on the fig 8.6 is:
A. Superior facet
B. Pedicle
C. Transverse process
D. Lamina
D. Lamina.
- During which of the I’ve contrast phases does the bladder wall enhances:
A. Early arterial
B. Corticomedullary
C. Nephrographic
D. Excretory
D. Nephrographic (70 - 90 sec).
- Coronary artery calcium ( CAC) quantitation by (MDCT) exam is used primarily to asses:
A. Aortic aneurysm
B. Atherosclerotic disease
C. Coronary artery disease
D. Ejection fraction
B. Atherosclerotic Disease
- Number 4 on fig 8.7 is:
A. Left common iliac artery
B. Right common iliac artery
C. Left common iliac vein
D. Right common iliac artery
C. Left common iliac vein.
- The best method for targeting the sacrum in the figure 8.7 for detailed exam:
A. Magnify the image x 2
B. Rescan the pt using a small SFOV
C. Retrospectively reconstruct the image using a small DFOV
D. Decrease the matrix dimension
C. Retrospective reconstruct the image using a small DFOV.
- Number 5 on the fig 8.7 is :
A. Right common iliac vein
B. Right ureter
C. Left common iliac vein
D. Inferior Mesenteric vein
B. Right ureter.
- Number 1 on the fig 8.7 is:
A. Psoas muscle
B. Gluteus medius muscle
C. iliacus muscle
D. Rectus abdominis muscle
D. Rectus abdominis muscle.
- A specialized CT exam involving the administration of an enteral contrast agent directly into the small bowel via gastric tube is:
A. CT enteroclysis
B. CT colonography
C. CT enterography
D. CT colonoscopy
A. CT enteroclysis.
- The epithelial lining of the urinary tract is called:
A. Omentum
B. Haustrum
C. Urothelium
D. Pyelocalyx
C. Urothelium.
- The primary drainage opening with in the sinus cavities, a common area for inflammation is:
A. Mucosal fossa
B. Adenovestibular complex
C. External olfactory canal
D. Ostiomeatal complex
D. Ostiomeatal complex.
- Number 1 on fig 8.8 is:
A. Right brachiocephalic artery
B. Right pulmonary artery
C. Right pericardiacophrenic artery
D. Right subclavian artery
B. Right pulmonary artery.
- Which best describes the type of image displayed on fig 8.8:
A. Coronal MIP
B. Direct coronal acquisition
C. Coronal MPR
D. Corol min-IP
A. Coronal MIP.
- Number 4 on fig 8.8 is:
A. Gastric artery
B. Inferior vena cava IVC
C. Superior mesenteric artery SMA
D. Descending aorta
D. Descending aorta.
- The area of image quality degradation indicated by # 3 on fig 8.8 is:
A. Aliasing artifact
B. Windmill artifact
C. Pulsation artifact
D. Beam - hardening artifact
C. Pulsation artifact.
- Number 2 on fig 8.8 is:
A. Aortic arch
B. Pulmonary trunk
C. Superior vena cava
D. Left anterior descending artery
B. Pulmonary trunk.
- During CT exam of the chest, the administration of saline after bolus injection of iv contrast helps alleviate artifact from dense contrast in the:
A. Ascending aorta
B. Superior vena cava
C. Descending aorta
D. Inferior vena cava
B. Superior vena cava.
- Delayed post contrast acquisition of the lower extremities after a CTA of the pulmonary arteries is termed:
A. CT venography
B. CaT perfusion
C. Femoral CTA
D. Iliac CTA
A. CT venography.
- Number 4 on the fig 8.9 is:
A. Third ventricle
B. Quadrigeminal cistern
C. Fourth ventricle
D. Sagittal sinus
C. Fourth ventricle.
- Number 2 on the fig 8.9 is:
A. Left posterior cerebral artery
B. Left middle cerebral artery
C. Left anterior cerebral artery
D. Left posterior communicating artery
B. Left middle cerebral artery.
- Number 5 on the fig 8.9 is:
A. Posterior communicating artery
B. Anterior communicating artery
C. Internal carotid artery
D. Basilar artery
D. Basilar artery.
- Number 3 on the fig 8.9 is:
A. Left posterior cerebral artery
B. Left middle cerebral artery
C. Left anterior cerebral artery
D. Left posterior communicating artery
A. Left posterior cerebral artery.
- The overall quality of MPR and volume-rendering 3-D images for carotid artery CTA may be improved by:
- Reducing KVp for an increase in displayed vessel opacification and contrast
- Retrospective reconstructions with 50% overlap in section increment
- Bolus-tracking software to maximize contrast enhancement
1, 2 and 3.
- Which is the most common sign of gastrointestinal (GI) pathology on CT images:
A. Fluid collection
B. Wall thickening
C. Air distention
D. Dense focal matter
B. Wall thickening.
- Number 2 on fig 8.10 is:
A. Right brachiocephalic vein
B. Left subclavian artery
C. Left brachiocephalic vein
D. Brachiocephalic artery
B. Left subclavian artery.
- Number 5 on fig 8.10 is:
A. Right brachiocephalic vein
B. Left subclavian artery
C. Left brachiocephalic vein
D. Brachiocephalic
A. Right brachiocephalic vein.
- Number 1 on the fig 8.10 is:
A. Right brachiocephalic vein
B. Left subclavian artery
C. Left brachiocephalic vein
D. Brachiocephalic artery
C. Brachiocephalic vein.
- Which number on fig 8.10 correspond to the left common carotid artery:
A. 1
B. 6
C. 4
D. 3
C. 4
- Arterial phase CT imaging of the liver is used to demonstrate:
A. Fatty infiltration
B. Hepatic cyst
C. Portal vein thrombosis
D. Hepatocellular carcinoma (HCC)
D. Hepatocellular carcinoma (HCC).
- Noncontrast CT of the urinary tract is a valuable tool in the investigation of:
A. Transitional cell carcinoma (TCC)
B. Urinary tract lithiasis
C. Renal artery stenosis
D. Ureteral duplication
B. Urinary tract lithiasis.
- Which techniques can be used to improve visualization of vocal cords:
- Oral thick barium paste
- CT acquisition with the mouth open as widely as tolerated
- Scanning while the pt pronates the letter “E”
3 only.
- Which number in fig 8.11 correspond to the superior mesenteric vein:
A. 3
B. 5
C. 1
D. 2
C.1
- Number 4 on the fig 8.11 correspond to:
A. Descending colon
B. Spleen
C. Adrenal gland
D. Renal vein
B. Spleen.
- Number 6 on fig 8.11 is:
A. Duodenum
B. Terminal ileum
C. Appendix
D. Pancreas
D. Pancreas
- Percutaneous drainage under CT guidance may be used for the aspiration of:
A. Chronic subdural hematoma
B. Hydrocephalus
C. Abdominal abscess
D, dissecting aortic aneurysm
D. Abdominal abscess.
- The device constructed to house the x-ray tube and data acquisition system (DAS) for a CT scanner is:
A. Central processing unit (CPU)
B. Generator
C. Array processor
D. Gantry
D. Gantry.
- Third-generation CT scanners use which scan geometries:
A. Translate-rotate
B. Rotate-stationary
C. Transaxial
D. Rotate-rotate
D. Rotate-rotate.
- QC determines that low contrast resolution of a CT is extremely poor. Likely cause:
- Tube arcing
- Increased electronic noise
- Decreases tube output
2 and 3 only.
- When one is viewing a maximum intensity projection (MIP) image, each pixel represents:
A. The maximum attenuation occurring within the voxel
B. The average attenuation occurring within the voxel
C. The minimum attenuation occurring within the voxel
D. All attenuation occurring within the voxel above set threshold value
A. The maximum attenuation occurring within the voxel.
- A CT image is reconstructed using 512^2 matrix and a display field of view of 40cm. What is the linear dimension of each pixel:
A. 0.0015mm
B. 0.08mm
C. 0.78mm
D. 1.28mm
Convert DFOV from cm -mm adding zero
Ex: 400mm divided by 512 matrix
C. 0.78
- Which statements about collimation of a CT beam is FALSE:
A. Collimation of the x-ray beam occurs both before and after the pt
B. Collimation of the beam occurs in the z- axis, thus affecting slice thickness
C. Increase in Collimation increase the intensity of the primary beam
D. Collimation of the CT x-ray beam is used to limit the detection of scatter radiation
C. Increase in collimation increases the intensity of the primary beam.
- Which may be used to describe the quantity of radiation emitted from the CT X-ray tube toward pt:
A. Effective mAs
B. Photon flux
C. Constant mAs
D. Photon fluence
D. Photon fluence.
- Which is the most common type of noise in a CT image:
A. Quantum noise
B. Electronic noise
C. Artifactual noise
D. Filter noise
A. Quantum noise.
- A picture archival and communications system (PACS) is connected with imaging modalities and other peripheral devices on a computerized communications system called:
A. Network
B. Web
C. Radiology information system (RIS)
D. Hospital information system (HIS)
A. Network.
- Which artifact is evident on the image in fig 8.12:
A. Blooming
B. Aliasing
C. Edge gradient effect
D. Ring artifact
C. Edge gradient effect.
- Which serves to reduce the image artifact on fig 8.12:
- Increase in filtration
- Increase in kvp
- Increase in section width
1 and 2 only.
- The image on the fig 8.12 was most likely displayed in a window level of:
A. -150
B. 0
C. +50
D. +400
C. +50
- The major disadvantage of the back - projection method of image reconstruction is the appearance of:
A. Partial volume effect
B. Ring artifacts
C. Gibb phenomenon
D. Star artifact
D. Star artifact.
- The most effective method of reducing involuntary motion on a CT image is:
A. Immobilization
B. Thorough explanation of the examination
C. Reduce scan time
D. Physical restraint
C. Reduce scan times
- The process of displaying CT images in a different orientation from the one used in the original reconstruction process is called:
A. Retrospective reconstruction
B. Prospective reconstruction
C. Multiplanar reformation
D. Multisegment reconstruction
C. Multiplanar reformation.
- The process of grayscale mapping of the CT image is called:
A. Analog -to-digital conversion
B. Retrospective reconstruction
C. Prospective reconstruction
D. Windowing
D. Windowing.
- In the formula used to calculate the linear attenuation coefficient, I=Ioe -ux , the symbol Io identifies the:
A. Euler constant
B. Incident intensity
C. Absorber thickness
D. Transmitted intensity
* hint= The lamber -beer law
B. Incident intensity.
- First- generation CT scanners posses which characteristics:
A. Pencils- thin X-ray beam
B. Silver halide detectors
C. Rotate - rotate geometry
D. Notating detector array
A. Pencil beam
- The intensity of the X-ray beam after it passes through an object to a detector is called:
A. Incident intensity
B. Ray
C. Transmitted intensity
D. Primary beam
C. Transmitted intensity
- An accurate, modern CT scanner posses a spatial resolution up to:
A. 10 Ip /mm
B. 25 Ip / mm
C. 10 Ip / cm
D. 25 Ip/ cm
D. 25 Ip/cm
- A high resolution comb is utilized by a multidetector CT (MDCT) detector array in effort to reduce:
A. Scatter radiation
B. Patient radiation dose
C. Low spatial frequency signal
D. High spatial frequency signal
A. Scatter radiation
- The distance btw the centers of two adjacent reconstructed CT images is:
A. Section width
B. Interpolation degree
C. Section interval
D. Sampling rate
C. Section interval.
- The maximum number of simultaneous sections a (MDCT) system can acquire per gantry rotation is controlled by the number of:
A. Detector rows
B. Data channels
C. Focal spots
D. X-ray tubes
B. Data channels.
- Matrix size describes which of the following:
A. Aperture size used during data acquisition
B. Number of pixels used to display image
C. Relationship between the field of view and the algorithm
D. The number of data channels available
B. Number of pixels used to display image.
- The circle on fig 8.13is used to:
A. Magnify a portion of the image
B. Localize an area for percutaneous biopsy
C. Perform a region of interest (ROI) measurement
D. Produce a Multiplanar reformation (MPR) image
C. Perform a region of interest (ROI) measurement.
- The density measurement performed in fig 8.13 yielded an average CT number of zero. This area consists of:
A. Fat
B. Blood
C. Water
D. Air
C. Water.
- The implementation of corrective actions to improve any identified performance inadequacies of CT system is:
A. Quality control
B. Uniformity
C. Quality assurance
D. Linearity
A. Quality control.
- The major disadvantage of the fan-or cone - shaped X-ray beam used in modern CT units in comparison with the pencil - thin beams of older units is:
A. Increased transmission measurement
B. Greater pt dose
C. Decreased transmission measurement
D. Excess tube wear
B. Greater pt dose
- 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 specific area of anatomic interest
1, 2 and 3.
- As the attenuation of a volume of tissue decreases, the transmitted intensity of a CT X-ray beam:
A. Increases
B. Remains unchanged
C. Decreases
D. Increases to a peak value and then rapidly decreases
A. Increases.
- Which parameters or factors is improved by the selection of a smaller X-ray tube filament:
A. Scan time
B. Spatial resolution
C. Heat rating
D. Signal to noise ratio (SNR)
B. Spatial resolution.
- The geometric efficiency of a CT detector is influenced primarily by the:
A. Atomic number of the detector material
B. Size of the detector element
C. Size of the tube filament
D. Amount of interspace material between detectors
D. Amount of interspace material between detectors.
- Which factors may affect the attenuation of an object during CT data acquisition:
A. Beam pitch
B. mA
C. KVp
D. Algorithm
C. KVp.
- An image that is reconstructed a second time with some change in technical factor is:
A. Reiterated
B. Post-processed
C. Retrospective
D. Reformatted
C. Retrospective.
- The Feldkamp - Davis - Kress (FDK) algorithm may be applied to MDCT acquisition data to overcome image artifacts from:
A. Pt motion
B. Beam hardening
C. Partial volume averaging
D. Beam divergence
D. Beam divergence.
- MDCT systems are typically capable of differentiating adjacent objects with attenuation differences as small as:
A. 3 HU
B. 10 HU
C. 25HU
D. 60HU
A. 3 HU
- The ability of a MDCT system to freeze motion and provide an image free of blurring is called:
A. In-plane spatial resolution
B. Longitudinal spatial resolution
C. Temporal resolution
D. Contrast resolution
*hint- stop- motion
C. Temporal resolution.
- Ring artifacts on the CT image are associated with which tube detector geometries:
A. Rotate- nutate
B. Rotate- stationary
C. Rotate-rotate
D. Translate - rotate
*hint- third generations
C. Rotate- rotate
- What is the maximum beam collimation for a MDCT system with 16 rows of 1.25mm detectors.
A. 2.5 mm
B. 5.0 mm
C. 20.0 mm
D. 40.0 mm
* hint - multiply 16x1.25
C. 20.0 mm
- The polyenergetic X-ray beam emitted from a CT X-ray tube is susceptible to artifacts resulting from phenomenon known as:
A. Beam hardening
B. Density bloom
C. Kerma
D. Partial volume
A. Beam hardening.
- In a MDCT system, which technical parameters determines the reconstructed section width:
A. Detector collimation
B. Number of data channels
C. Beam collimation
D. Detector pitch
A. Detector collimation.
- Daily air or water calibration of CT system is performed to evaluate which components of image quality:
A. Contrast resolution
B. Temporal resolution
C. Uniformity
D. Linearity
D. Linearity.
- Pixels whose average attenuation coefficients are less than the coefficient of water have which types of CT numbers:
A. Extremely large
B. High positive
C. Negative
D. High contrast
C. Negative.
- Which actions would serve to magnify the CT image on the display monitor:
A. Decrease matrix size
B. Increase scan field of view
C. Decrease display field of view
D. Increase display field of view
*hint- targeting
C. Decrease display field of view.
- The bit depth of a digital imaging system defines the number of information bits contained within each:
A. Pixel
B. Matrix
C. Axial image
D. MPR
A. Pixel
- The technical factors necessary for the acquisition of an isotropic data set are:
- Thin detector collimation
- High mA setting
- Small DFOV
1 and 3 only.
- The limiting resolution of the bone algorithm in the fig 8.14 is:
A. 6.1 Ip/cm
B. 9.5 Ip/cm
C. 14.6 Ip/cm
D. 15.5 Ip/cm
C. 14.6 Ip/cm
- At a MTF of 20%, which reconstruction algorithm will demonstrate the greatest number line in pairs per cm(Ip/cm):
A. Bone
B. Standard
C. Smooth
D. Impossible to determine from information provided
A. Bone.
- When one is assessing a MTF graph on fig 8.14 the limiting resolution determined at a point where the signal frequency corresponds to a particular object has reached:
A. 10%
B. 20%
C. 50%
D. 100%
A. 10%
- In MDCT, the combined thickness of all of the sections simultaneously acquired with each gantry rotation is:
A. Detector configuration
B. Beam pitch
C. Detector pitch
D. Total collimation
D. Total collimation.
- MDCT systems typically employ which types of detectors:
A. Tungsten ring
B. Solid- state scintillation
C. Charged - coupled device (CCD)
D. Gas ionization
B. Solid- state scintillation.
- Which technical adjustments may be employed to reduce step artifact in in a multiplanar reformation CT image:
- Acquisition of an isotropic data set
- Overlapping section increment
- Increase in effective mAs
1 and 2 only.
- Which is a manifestation of partial volume artifact:
A. Cupping
B. Hounsfield bar
C. Aliasing
D. Streaking
A. Cupping.
- during volumetric CT acquisition, the slice sensitivity profile ( SSP) graphically represents:
A. Effective section width
B. Dose profile
C. Beam width
D. Detector collimation
A. Effectively section width.
- An increase in the sampling rate during CT data acquisition corresponds to an increase in:
A. Views per rotation
B. Patient radiation dose
C. Image noise
D. Matrix size
* hint ( VPR)
A. Views per rotation.