Radiological Physics & Imaging Principles
Exam 2026/2027: 80 Practice Questions
with Explanations | Anode Heel Effect, X-
Ray Properties, Digital Imaging &
Radiation Safety
Description:
Master radiological physics for 2026/2027 with this comprehensive exam prep guide
covering anode heel effect, X-ray properties, digital imaging, scatter radiation, ALARA
principles, and geometric factors. Features 80 multiple-choice questions with detailed
answers and explanations.
Download now to ace your radiologic technology board exams and clinical competency
assessments!
, Radiology Physics Exam 2026/2027: 80 Questions & Answers
SECTION A: ANODE HEEL EFFECT & GEOMETRIC PRINCIPLES
Question 1
The Anode Heel Effect refers to the phenomenon in which:
A) The X-ray beam intensity is greatest toward the anode side
B) The X-ray beam intensity is greatest toward the cathode side
C) The X-ray beam intensity is uniform across the entire field
D) The X-ray beam intensity is greatest at the center of the field
Answer: B
Explanation: The anode heel effect describes the non-uniform intensity distribution of the X-
ray beam, where the greatest intensity is observed toward the cathode side of the tube. This
occurs because photons emitted from the anode side must travel through a greater thickness
of the anode material, resulting in increased attenuation. This phenomenon has significant
clinical implications, particularly in procedures where optimal image quality requires
consideration of beam intensity distribution across the image receptor.
Question 2
The anatomical structure commonly referred to as the heel of the foot is properly termed the:
A) Calcaneus
B) Talus
C) Navicular
D) Cuboid
Answer: A
Explanation: The calcaneus is the correct anatomical term for the heel bone. It is the largest
tarsal bone and serves as the primary weight-bearing structure of the foot, supporting the
body's weight during standing and locomotion. The calcaneus articulates superiorly with the
talus and anteriorly with the cuboid bone.
,Question 3
The hip joint is anatomically referred to as the:
A) Os coxae
B) Acetabulum
C) Symphysis pubis
D) Ischium
Answer: A
Explanation: Os coxae (also known as the innominate bone) is the correct anatomical term
for the hip bone. It is formed by the fusion of three bones: the ilium, ischium, and pubis. The
hip joint proper is formed by the articulation of the femoral head with the acetabulum of the
os coxae.
Question 4
The abbreviation SID in radiographic imaging stands for:
A) Source-to-Image Distance
B) Source-to-Object Distance
C) Source-to-Intensifier Distance
D) Source-to-Ionization Distance
Answer: A
Explanation: SID (Source-to-Image Distance) refers to the distance from the X-ray tube's
focal spot (source) to the image receptor. This distance is critical in determining image
magnification, geometric unsharpness, and patient dose. Most modern radiographic protocols
use an SID of approximately 100-180 cm depending on the examination being performed.
Proper SID selection is essential for maintaining image quality while minimizing patient
radiation exposure.
Question 5
SOD represents the distance from the:
A) Source of radiation to the patient's skin surface
B) Source of radiation to the image receptor
C) Object to the image receptor
D) Source of radiation to the part being examined
, Answer: D
Explanation: SOD (Source-to-Object Distance) is the measurement from the X-ray tube
focal spot to the anatomical structure being imaged. This distance directly influences the
magnification factor and the geometric unsharpness of the resulting radiographic image. The
relationship between SOD, OID, and SID follows the formula: SID = SOD + OID.
Understanding these geometric relationships is fundamental to optimizing radiographic
technique and image quality.
Question 6
OID in radiographic imaging refers to:
A) Object-to-Image Distance
B) Object-to-Intensifier Distance
C) Original-Image Distance
D) Offset-Image Distance
Answer: A
Explanation: OID (Object-to-Image Distance) represents the distance between the
anatomical structure being examined and the image receptor. This distance significantly
impacts image magnification and geometric unsharpness. A larger OID increases image
magnification and reduces spatial resolution, while a smaller OID produces a more accurately
sized image with better detail. For optimal image quality, the OID should be minimized
whenever clinically practical.
Question 7
The mathematical relationship between SOD, OID, and SID is expressed as:
A) SID = SOD × OID
B) SID = SOD + OID
C) SID = SOD - OID
D) SID = SOD ÷ OID
Answer: B
Explanation: The fundamental geometric relationship states that the Source-to-Image
Distance (SID) equals the sum of the Source-to-Object Distance (SOD) and the Object-to-
Image Distance (OID). This relationship forms the basis for calculating magnification factors
Exam 2026/2027: 80 Practice Questions
with Explanations | Anode Heel Effect, X-
Ray Properties, Digital Imaging &
Radiation Safety
Description:
Master radiological physics for 2026/2027 with this comprehensive exam prep guide
covering anode heel effect, X-ray properties, digital imaging, scatter radiation, ALARA
principles, and geometric factors. Features 80 multiple-choice questions with detailed
answers and explanations.
Download now to ace your radiologic technology board exams and clinical competency
assessments!
, Radiology Physics Exam 2026/2027: 80 Questions & Answers
SECTION A: ANODE HEEL EFFECT & GEOMETRIC PRINCIPLES
Question 1
The Anode Heel Effect refers to the phenomenon in which:
A) The X-ray beam intensity is greatest toward the anode side
B) The X-ray beam intensity is greatest toward the cathode side
C) The X-ray beam intensity is uniform across the entire field
D) The X-ray beam intensity is greatest at the center of the field
Answer: B
Explanation: The anode heel effect describes the non-uniform intensity distribution of the X-
ray beam, where the greatest intensity is observed toward the cathode side of the tube. This
occurs because photons emitted from the anode side must travel through a greater thickness
of the anode material, resulting in increased attenuation. This phenomenon has significant
clinical implications, particularly in procedures where optimal image quality requires
consideration of beam intensity distribution across the image receptor.
Question 2
The anatomical structure commonly referred to as the heel of the foot is properly termed the:
A) Calcaneus
B) Talus
C) Navicular
D) Cuboid
Answer: A
Explanation: The calcaneus is the correct anatomical term for the heel bone. It is the largest
tarsal bone and serves as the primary weight-bearing structure of the foot, supporting the
body's weight during standing and locomotion. The calcaneus articulates superiorly with the
talus and anteriorly with the cuboid bone.
,Question 3
The hip joint is anatomically referred to as the:
A) Os coxae
B) Acetabulum
C) Symphysis pubis
D) Ischium
Answer: A
Explanation: Os coxae (also known as the innominate bone) is the correct anatomical term
for the hip bone. It is formed by the fusion of three bones: the ilium, ischium, and pubis. The
hip joint proper is formed by the articulation of the femoral head with the acetabulum of the
os coxae.
Question 4
The abbreviation SID in radiographic imaging stands for:
A) Source-to-Image Distance
B) Source-to-Object Distance
C) Source-to-Intensifier Distance
D) Source-to-Ionization Distance
Answer: A
Explanation: SID (Source-to-Image Distance) refers to the distance from the X-ray tube's
focal spot (source) to the image receptor. This distance is critical in determining image
magnification, geometric unsharpness, and patient dose. Most modern radiographic protocols
use an SID of approximately 100-180 cm depending on the examination being performed.
Proper SID selection is essential for maintaining image quality while minimizing patient
radiation exposure.
Question 5
SOD represents the distance from the:
A) Source of radiation to the patient's skin surface
B) Source of radiation to the image receptor
C) Object to the image receptor
D) Source of radiation to the part being examined
, Answer: D
Explanation: SOD (Source-to-Object Distance) is the measurement from the X-ray tube
focal spot to the anatomical structure being imaged. This distance directly influences the
magnification factor and the geometric unsharpness of the resulting radiographic image. The
relationship between SOD, OID, and SID follows the formula: SID = SOD + OID.
Understanding these geometric relationships is fundamental to optimizing radiographic
technique and image quality.
Question 6
OID in radiographic imaging refers to:
A) Object-to-Image Distance
B) Object-to-Intensifier Distance
C) Original-Image Distance
D) Offset-Image Distance
Answer: A
Explanation: OID (Object-to-Image Distance) represents the distance between the
anatomical structure being examined and the image receptor. This distance significantly
impacts image magnification and geometric unsharpness. A larger OID increases image
magnification and reduces spatial resolution, while a smaller OID produces a more accurately
sized image with better detail. For optimal image quality, the OID should be minimized
whenever clinically practical.
Question 7
The mathematical relationship between SOD, OID, and SID is expressed as:
A) SID = SOD × OID
B) SID = SOD + OID
C) SID = SOD - OID
D) SID = SOD ÷ OID
Answer: B
Explanation: The fundamental geometric relationship states that the Source-to-Image
Distance (SID) equals the sum of the Source-to-Object Distance (SOD) and the Object-to-
Image Distance (OID). This relationship forms the basis for calculating magnification factors
