Basic knowledge of medical imaging past exam questions (64)-2020 Tianjin medical health
1. About the collimator the following statements are wrong:
A. Anterior collimator's role is to control the width of the X-ray beam in the direction of the body's long axis parallel to the direction of the body, and thus control the thickness of the scanning layer
B. Anterior collimator Reduces interference from scattered rays in directions other than the imaging plane
C. X-ray tube side collimator, also known as the anterior collimator
D. Detector side collimator, also known as the posterior collimator
E. The collimator reduces the patient's surface radiation dose
2. The following statements about the baseline of a CT scan of the cranial brain are incorrect:
A. A. The auditory orbital line is the line between the infraorbital rim and the ipsilateral foramen magnum
B. The auditory canthus line is the line between the right (left) foramen magnum and the right (left) canthus magnum, which is commonly used for CT scans of the head
C. The auditory brow line is the line between the midpoint of the upper edge of the brow and the ipsilateral foramen magnum
D. The auditory canthus line passes through the fossa of the eye, the middle cranial recess, and the upper posterior cranial recess in profile
E. The auditory brow line is the line that is opposite to the tissues of the fourth ventricle and basal ganglia regions
E. The auditory brow line is opposite to the line of the fourth ventricle and basal ganglia regions. ventricle and basal ganglia area tissues are better displayed
3. The correct statement about CT photography of the cranial brain and pharynx is:
A. When cranial lesions or intracranial lesions encroach on the skull, additional bone windows are not required
B. The window width of the bone window of the cranial brain ranges from 300 to 1,000 HU, and the window position is from 30 to 50 HU
C. Cranial brain soft-tissue window photography: the window width is from 1200~1500HU, window position 35~45HU
D. Laryngeal scanning can be instructed to continuously pronounce the letter E sound, so that the vocal cords are inwardly retracted and the pyriform fossa is dilated
E. Pharynx and larynx scans are performed with a layer thickness of 10mm, and small lesions can be performed with a layer thickness of 2~3mm, with the reconstruction spacing being the same as the layer thickness
4. The following statements about the post-processing of CT images are incorrect:
A. CT image post-processing: window width of 300~1000HU, window position 30~50HU
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A. Multi-planar reorganization (MPR) is a two-dimensional image post-processing technique
B. Curved surface reorganization (CPR) is a two-dimensional image post-processing technique
C. Surface masking technique (SSD) is a two-dimensional image post-processing technique
D. Maximum Intensity Projection (MIP) is a three-dimensional image post-processing technique
E. Surface masking technique (SSD) is a three-dimensional image post-processing technique
5. The following factors affecting the generation of X-rays are incorrectly described:
A. The intensity of continuous X-rays is directly proportional to the atomic number of the target material
B. The higher the atomic number of the target material of the anode, the lower the intensity of the X-rays produced
C. The magnitude of the tube current does not affect the quality of the X-rays
D. The tube current is not a factor in the quality of the X-rays.
D. The higher the tube current, the more electrons hit the anode target and the greater the X-ray intensity
E. The maximum energy of the electrons depends on the peak value of the tube voltage
6. Which of the following is not a physical property of X-rays:
A. Penetration
B. Fluorescence
C. Thermal effect
D. Ionization
E. Ionization
Function of the X-rays
Function of the X-rays
Function of the X-rays
D. Ionization
D. Function of the X-ray Ionization
E. Coloring
Reference Answer and Analysis
1. Reference Answer B. Explanation: There are two types of collimators, one is the X-ray tube side collimator, also known as the anterior collimator, which is designed to control the width of the X-ray beam in the direction parallel to the long axis of the human body, and thus the thickness of the scanned layer. The other is the detector side collimator, also called the rear collimator, its slit is aligned with a detector, so that the detector only receives perpendicular to the incident detector rays, to minimize interference from scattered rays from the direction of the imaging plane outside. The auditory canthus line is the line between the right (left) lateral external auricle and the right (left) lateral canthus. This line is often used as the baseline for head CT scans. The auditory eyebrow line is the line between the midpoint of the upper edge of the eyebrow and the ipsilateral external aperture, and the image scanned through this line is better for displaying the tissue structure of the fourth ventricle and the basal ganglia, passing through the lowest point of the three cranial recesses, and the scanning scope is more comprehensive. Skull base, internal auditory tract lesions; craniocerebral trauma; cranial lesions or intracranial lesions invading the skull, must be added to the bone window. The window width of the bone window is 1000~1400 HU, and the window position is 300~500 HU.For scalp soft tissue lesions, soft tissue window is used. Soft tissue window photography: window width 300~400HU, window position 35~45HU. and the pharynx scanning layer thickness with 5mm, not 10mm. so this question choose D.
4. reference answer C. Analysis: two-dimensional post-processing techniques including multi-planar reorganization (MPR), surface reorganization (CPR). Surface masking (SSD), maximum density projection (MIP), minimum density projection (MinIP), simulated endoscopy technology (CTVE), volumetric imaging (VR) and so on belong to three-dimensional post-processing technology.
5. Reference answer B. Factors affecting the production of continuous X-rays: (1) target material: continuous X-ray intensity is proportional to the atomic number of the target material, in the case of the tube voltage and tube current is the same, the higher the atomic number of the target material of the anode, the greater the intensity of X-rays; (2) tube current: the size of the tube current does not affect the X-rays of the quality, but in a certain tube voltage, the intensity of X-rays depends on the tube current. (2) tube current: the size of the tube current does not affect the quality of X-rays, but at a certain tube voltage, the intensity of X-rays depends on the tube current, the larger the tube current, indicating that the number of electrons hitting the anode target surface more, the greater the intensity of the X-ray. (3) tube voltage: the maximum photon energy in the X-ray beam is equal to the kinetic energy of high-speed electron collision target material, and the maximum energy of the electron depends on the peak of the tube voltage, so change the tube voltage also changes the maximum photon energy, the shape of the entire X-ray spectrum changes. (4) High voltage waveform.
6. Reference answer E. Analysis: X-ray properties are classified as follows: 1. Physical properties: invisible, non-electrical, penetrating, fluorescence, ionization, thermal 2. Chemical properties: photosensitive, coloring 3. biological effect properties.