ARDMS Pediatric Sonography (PS) Actual Exam 2026/2027 | Complete
Practice Questions, Correct Answers & Detailed Rationales
DOMAIN 1 — ANATOMY AND PHYSIOLOGY
Questions 1–78
Neonatal Brain and Skull
1. Which structure is normally visualized as a midline echogenic landmark on
neonatal cranial ultrasound?
A. Caudate nucleus
B. Falx cerebri
C. Thalamus
D. Hippocampus
Correct Answer: B. Falx cerebri
Rationale: The falx cerebri is a midline dural structure that appears echogenic and
separates the cerebral hemispheres.
2. The anterior fontanelle is particularly useful for neonatal cranial sonography
because it:
A. Eliminates the need for Doppler
B. Provides an acoustic window through the skull
C. Contains cerebrospinal fluid
D. Directly visualizes the cerebellar vermis only
Correct Answer: B. Provides an acoustic window through the skull
Rationale: The open anterior fontanelle permits ultrasound transmission into the
brain without significant attenuation from calvarial bone.
3. Which ventricular structure is normally located near the midline and is
commonly assessed on coronal neonatal brain images?
A. Lateral ventricle
B. Fourth ventricle
,C. Third ventricle
D. Cerebral aqueduct
Correct Answer: A. Lateral ventricle
Rationale: The frontal and body portions of the lateral ventricles are routinely
assessed through the anterior fontanelle.
4. The caudothalamic groove is clinically important because it is a common site
for:
A. Germinal matrix hemorrhage
B. Choroid plexus cysts
C. Periventricular leukomalacia
D. Cerebellar hemorrhage
Correct Answer: A. Germinal matrix hemorrhage
Rationale: The germinal matrix is highly vascular in premature infants and lies
near the caudothalamic groove.
5. Which structure produces cerebrospinal fluid within the ventricular system?
A. Falx
B. Choroid plexus
C. Corpus callosum
D. Septum pellucidum
Correct Answer: B. Choroid plexus
Rationale: The choroid plexus is specialized vascular tissue that produces most
cerebrospinal fluid.
6. The corpus callosum primarily connects the:
A. Cerebellum and brainstem
B. Right and left cerebral hemispheres
C. Thalami and basal ganglia
D. Frontal and occipital lobes only
Correct Answer: B. Right and left cerebral hemispheres
Rationale: The corpus callosum is the major commissural fiber bundle connecting
the cerebral hemispheres.
,7. Which structure is located posteriorly and inferiorly in the neonatal brain?
A. Frontal horn
B. Cerebellum
C. Caudate nucleus
D. Septum pellucidum
Correct Answer: B. Cerebellum
Rationale: The cerebellum lies in the posterior fossa, posterior to the brainstem.
8. Which cranial ultrasound plane is especially useful for evaluating the corpus
callosum?
A. Midline sagittal
B. Coronal temporal
C. Axial facial
D. Transorbital
Correct Answer: A. Midline sagittal
Rationale: The midline sagittal plane demonstrates the corpus callosum along its
anterior-to-posterior course.
9. The cavum septum pellucidum is located between the:
A. Cerebellar hemispheres
B. Frontal horns of the lateral ventricles
C. Temporal horns
D. Fourth ventricle and aqueduct
Correct Answer: B. Frontal horns of the lateral ventricles
Rationale: The septum pellucidum forms a thin partition between the frontal
horns.
10. Which brain structure forms the floor of the third ventricle?
A. Thalamus only
B. Hypothalamic region
C. Corpus callosum
D. Falx cerebri
, Correct Answer: B. Hypothalamic region
Rationale: The hypothalamus contributes significantly to the floor of the third
ventricle.
11. The fourth ventricle is located between the:
A. Cerebral hemispheres and corpus callosum
B. Brainstem and cerebellum
C. Thalami and lateral ventricles
D. Frontal lobes and frontal horns
Correct Answer: B. Brainstem and cerebellum
Rationale: The fourth ventricle lies anterior to the cerebellum and posterior to the
pons and medulla.
12. Which structure is commonly used as an internal landmark for assessing
ventricular size?
A. Lateral ventricle
B. Medulla
C. Pituitary gland
D. Optic nerve
Correct Answer: A. Lateral ventricle
Rationale: Ventricular size, particularly the atrium of the lateral ventricle, is
routinely assessed in neonates.
13. In a normal premature infant, the germinal matrix is best described as:
A. A calcified structure
B. A vascular cellular layer near the ventricles
C. A CSF-filled cavity
D. A dural sinus
Correct Answer: B. A vascular cellular layer near the ventricles
Rationale: The germinal matrix contains fragile vessels and is particularly
prominent in premature infants.
14. Which structure separates the two cerebral hemispheres?
A. Corpus callosum
Practice Questions, Correct Answers & Detailed Rationales
DOMAIN 1 — ANATOMY AND PHYSIOLOGY
Questions 1–78
Neonatal Brain and Skull
1. Which structure is normally visualized as a midline echogenic landmark on
neonatal cranial ultrasound?
A. Caudate nucleus
B. Falx cerebri
C. Thalamus
D. Hippocampus
Correct Answer: B. Falx cerebri
Rationale: The falx cerebri is a midline dural structure that appears echogenic and
separates the cerebral hemispheres.
2. The anterior fontanelle is particularly useful for neonatal cranial sonography
because it:
A. Eliminates the need for Doppler
B. Provides an acoustic window through the skull
C. Contains cerebrospinal fluid
D. Directly visualizes the cerebellar vermis only
Correct Answer: B. Provides an acoustic window through the skull
Rationale: The open anterior fontanelle permits ultrasound transmission into the
brain without significant attenuation from calvarial bone.
3. Which ventricular structure is normally located near the midline and is
commonly assessed on coronal neonatal brain images?
A. Lateral ventricle
B. Fourth ventricle
,C. Third ventricle
D. Cerebral aqueduct
Correct Answer: A. Lateral ventricle
Rationale: The frontal and body portions of the lateral ventricles are routinely
assessed through the anterior fontanelle.
4. The caudothalamic groove is clinically important because it is a common site
for:
A. Germinal matrix hemorrhage
B. Choroid plexus cysts
C. Periventricular leukomalacia
D. Cerebellar hemorrhage
Correct Answer: A. Germinal matrix hemorrhage
Rationale: The germinal matrix is highly vascular in premature infants and lies
near the caudothalamic groove.
5. Which structure produces cerebrospinal fluid within the ventricular system?
A. Falx
B. Choroid plexus
C. Corpus callosum
D. Septum pellucidum
Correct Answer: B. Choroid plexus
Rationale: The choroid plexus is specialized vascular tissue that produces most
cerebrospinal fluid.
6. The corpus callosum primarily connects the:
A. Cerebellum and brainstem
B. Right and left cerebral hemispheres
C. Thalami and basal ganglia
D. Frontal and occipital lobes only
Correct Answer: B. Right and left cerebral hemispheres
Rationale: The corpus callosum is the major commissural fiber bundle connecting
the cerebral hemispheres.
,7. Which structure is located posteriorly and inferiorly in the neonatal brain?
A. Frontal horn
B. Cerebellum
C. Caudate nucleus
D. Septum pellucidum
Correct Answer: B. Cerebellum
Rationale: The cerebellum lies in the posterior fossa, posterior to the brainstem.
8. Which cranial ultrasound plane is especially useful for evaluating the corpus
callosum?
A. Midline sagittal
B. Coronal temporal
C. Axial facial
D. Transorbital
Correct Answer: A. Midline sagittal
Rationale: The midline sagittal plane demonstrates the corpus callosum along its
anterior-to-posterior course.
9. The cavum septum pellucidum is located between the:
A. Cerebellar hemispheres
B. Frontal horns of the lateral ventricles
C. Temporal horns
D. Fourth ventricle and aqueduct
Correct Answer: B. Frontal horns of the lateral ventricles
Rationale: The septum pellucidum forms a thin partition between the frontal
horns.
10. Which brain structure forms the floor of the third ventricle?
A. Thalamus only
B. Hypothalamic region
C. Corpus callosum
D. Falx cerebri
, Correct Answer: B. Hypothalamic region
Rationale: The hypothalamus contributes significantly to the floor of the third
ventricle.
11. The fourth ventricle is located between the:
A. Cerebral hemispheres and corpus callosum
B. Brainstem and cerebellum
C. Thalami and lateral ventricles
D. Frontal lobes and frontal horns
Correct Answer: B. Brainstem and cerebellum
Rationale: The fourth ventricle lies anterior to the cerebellum and posterior to the
pons and medulla.
12. Which structure is commonly used as an internal landmark for assessing
ventricular size?
A. Lateral ventricle
B. Medulla
C. Pituitary gland
D. Optic nerve
Correct Answer: A. Lateral ventricle
Rationale: Ventricular size, particularly the atrium of the lateral ventricle, is
routinely assessed in neonates.
13. In a normal premature infant, the germinal matrix is best described as:
A. A calcified structure
B. A vascular cellular layer near the ventricles
C. A CSF-filled cavity
D. A dural sinus
Correct Answer: B. A vascular cellular layer near the ventricles
Rationale: The germinal matrix contains fragile vessels and is particularly
prominent in premature infants.
14. Which structure separates the two cerebral hemispheres?
A. Corpus callosum
