Neurological Imaging Quiz

Here are detailed explanations for each question, including the correct answer and additional information:

Question 1: The best neuroimaging technique for the brain is:

Answer: D. Magnetic Resonance Imaging (MRI)

Explanation: MRI is the superior imaging technique for the brain due to its high resolution and ability to clearly distinguish between different soft tissues, especially brain tissue, cerebrospinal fluid, meninges, and blood vessels. MRI provides detailed images of brain structure, helping to detect early and accurately conditions like brain tumors, stroke, encephalitis, and neurodegenerative diseases.

Note:

• Color Doppler ultrasound is mainly used to assess blood flow in peripheral blood vessels, not suitable for diagnosing brain pathologies.

• Conventional X-ray only provides images of the skull structure, limited in diagnosing soft tissue diseases in the brain.

• CT has lower resolution than MRI, not able to differentiate soft tissues as clearly as MRI.

• Radioactive isotope scanning is primarily used to evaluate brain function, not for diagnosing structure.

Question 2: CT scan is an optimal method for brain injury because:

Answer: D. It can evaluate both skull and brain injuries

Explanation: CT can clearly display the skull structure and also allows for the assessment of soft tissue injuries in the brain, such as bleeding, edema, and brain tissue damage.

Note:

• CT can only assess skull injuries to a limited extent, unable to distinguish subtle injuries like small cracks.

• MRI is a superior method for detailed evaluation of brain injuries in cases of head trauma.

Question 3: A lucency in the skull on X-ray signifies:

Answer: A. Skull bone resorption

Explanation: A lucency on a conventional X-ray indicates an area where bone has been lost, often due to bone resorption.

Note:

• Skull bone sclerosis usually appears as a denser area on an X-ray.

• Localized skull osteoporosis often doesn’t produce clear images on conventional X-rays.

• Skull bone sclerosis often appears as a localized denser area on an X-ray.

Question 4: A denser area in the skull on X-ray signifies:

Answer: D. Skull bone sclerosis

Explanation: A denser area on a conventional X-ray usually indicates an area where the bone is thicker than normal, often due to bone sclerosis.

Note:

• Skull bone resorption often appears as a lucency on an X-ray.

• Localized skull osteoporosis often doesn’t produce clear images on conventional X-rays.

• Skull decalcification also shows a denser area, but it’s usually an uneven density and can look like a “honeycomb” pattern.

Question 5: The main X-ray sign of spinal degeneration is:

Answer: D. All of the above.

Explanation: Spinal degeneration is often characterized by several features on conventional X-rays:

• Narrowing of the intervertebral joint space: Due to dehydration and atrophy of the intervertebral disc.

• Osteophytes of the vertebral bodies: Due to calcium deposition in the damaged area.

• Subchondral sclerosis of the vertebral bodies: Due to bone growth in the weight-bearing area.

Note:

• In addition to these signs, other features may be present, such as posterior articular process osteophytes, facet joint changes, abnormal spinal curvature, etc.

Question 6: The image of an extradural hematoma on a brain CT scan is:

Answer: A. Biconvex lens shape

Explanation: Extradural hematomas usually appear as a biconvex lens shape, with a clear boundary from the surrounding brain tissue.

Note:

• A biconcave lens shape often characterizes subdural hematomas.

• Brain parenchyma edema usually doesn’t have a clear boundary.

• A space-occupying lesion within the brain parenchyma could be a brain tumor, brain abscess, etc.

Question 7: The best neuroimaging technique for the spinal cord is:

Answer: D. Magnetic Resonance Imaging (MRI)

Explanation: MRI allows for detailed evaluation of the spinal cord structure, including both soft tissue and bone, helping to detect early and accurately conditions like disc herniation, spinal stenosis, spinal tumors, and meningitis.

Note:

• Color Doppler ultrasound is not suitable for diagnosing spinal cord pathologies.

• Conventional X-ray can only assess the structure of the spine bones, not able to display the spinal cord structure.

• CT has lower resolution than MRI, unable to clearly differentiate structures within the spinal canal.

• Radioactive isotope scanning is primarily used to evaluate function, not suitable for diagnosing spinal cord structure.

Question 8: The crucial postures for conventional spinal X-ray are:

Answer: D. All of the above.

Explanation: To comprehensively evaluate the spine structure, X-rays need to be taken in several positions:

• Anteroposterior (AP): To assess spinal curvature, joint spaces, vertebral height, etc.

• Lateral: To assess intervertebral joint spaces, presence of osteophytes, disc degeneration, etc.

• Oblique: To assess structures in specific locations, like the intervertebral foramina.

Note:

• Choosing the appropriate imaging position depends on the purpose and the area being assessed.

Question 9: On an anteroposterior (AP) spinal X-ray, we can see:

Answer: A. Spinal fracture

Explanation: Anteroposterior (AP) spinal X-rays allow the detection of abnormalities in bone structure, including fractures.

Note:

• Other conditions like spinal cord compression, spondylolisthesis, spinal tumors, and spinal inflammation are usually not detectable on an AP spinal X-ray.

Question 10: The main X-ray signs of spinal degeneration are:

Answer: E. All of the above.

Explanation: Spinal degeneration often presents with multiple features on X-ray:

• Disc space narrowing: Due to dehydration and atrophy of the intervertebral disc.

• Facet joint sclerosis: Due to calcium deposition in the damaged area.

• Osteophytes on the anterior and lateral margins of the vertebral bodies: Due to bone growth in the weight-bearing area.

• Posterior articular process osteophytes, facet joint changes, and intervertebral foramina with a “keyhole” appearance: Due to calcium deposition and structural bone changes.

Note:

• The combination of these signs on X-ray helps to determine the severity of spinal degeneration.

Question 11: The “blind vertebra” image on a spinal X-ray is a sign of:

Answer: D. Tuberculosis of the spine (Pott’s disease)

Explanation: A “blind vertebra” refers to a situation where the vertebral body has completely disappeared, often due to tuberculosis of the spine (Pott’s disease).

Note:

• Spinal fracture usually shows a clear fracture line.

• Spinal osteomyelitis often has images of inflammation in the affected area.

• Spinal cord compression by a tumor usually shows an image of the tumor compressing the spinal canal.

Question 12: An intramedullary tumor can be detected using:

Answer: D. Magnetic Resonance Imaging (MRI)

Explanation: MRI is the superior neuroimaging technique for detecting intramedullary tumors because it allows clear differentiation between tumor tissue and spinal cord tissue, as well as accurate assessment of tumor size, location, and extent of spread.

Note:

• Color Doppler ultrasound, conventional X-ray, and CT are not suitable for diagnosing intramedullary tumors.

• Radioactive isotope scanning is primarily used to evaluate function, not suitable for diagnosing intramedullary tumors.

Question 13: Brain metastases on MRI have the following characteristics:

Answer: D. All of the above

Explanation: Brain metastases often have the following features on MRI:

• They can occur in any area of the brain: Due to the metastatic nature of cancer cells.

• Multiple lesions are often seen: Due to multiple cancer cells metastasizing to the brain.

• Lesions are often round, with decreased or increased signal intensity: Due to differences in the histological properties of cancer cells compared to brain tissue.

Note:

• Brain metastases are a serious condition that requires prompt treatment.

Question 14: Transfontanelle ultrasound is an imaging technique used to diagnose:

Answer: D. All of the above

Explanation: Transfontanelle ultrasound is a non-invasive and safe imaging technique for infants that can help detect early brain pathologies in young children:

• Space-occupying lesions in the skull: Like brain tumors, meningiomas, etc.

• Shift in midline structures: Due to tumor or hematoma compression.

• Ventricular dilatation: Due to blockage of cerebrospinal fluid drainage pathways.

Note:

• This technique is only applicable in infants before the fontanelle closes.

Question 15: A contrast-enhanced CT scan of the brain is indicated in cases of:

Answer: E. All of the above

Explanation: Administering contrast agents in brain CT scans helps to enhance contrast, making it easier to distinguish between different soft tissue structures, especially blood vessels. This helps to diagnose conditions accurately:

• Brain tumor: Distinguish tumor tissue from surrounding brain tissue.

• Brain abscess: Identify the exact location and size of the abscess.

• Cerebral venous sinus thrombosis: Display the course of the thrombosed vein clearly.

• Meningoencephalitis: Evaluate the extent of inflammation.

Note:

• Contrast agents can cause allergic reactions in some individuals, and careful monitoring is necessary.

Question 16: When a large brain tumor is present, we can see on a CT scan:

Answer: D. All of the above

Explanation: Large brain tumors often produce clear signs on CT scans:

• Mass effect within brain parenchyma: Image of the tumor compressing surrounding brain tissue.

• Shifting of midline structures: Due to the tumor compressing midline brain structures.

• Ventricular displacement and asymmetry: Due to tumor compression of the ventricular system.

Note:

• These signs are only initial suggestions, and additional investigations are needed for definitive diagnosis.

Question 17: The image of a brain-meningeal hemorrhage not caused by trauma on a CT scan, a common cause is cerebrovascular accident in older people with hypertension.

Answer: A. True

Explanation: Brain-meningeal hemorrhage not caused by trauma is often due to ruptured aneurysms, atherosclerosis, or other conditions. Older people with hypertension are prone to ruptured aneurysms leading to brain hemorrhage.

Note:

• Brain-meningeal hemorrhage can be fatal or cause severe disability if not treated promptly.

Question 18: Brain MRI provides more information than brain CT.

Answer: A. True

Explanation: MRI has higher resolution than CT, allowing for clearer differentiation between different soft tissues, especially brain tissue. MRI can detect early and accurately brain lesions, aiding in timely diagnosis and treatment.

Note:

• MRI is not a complete replacement for CT but is a complementary technique for detailed evaluation of neurological conditions.

Question 19: In cases of brain-meningeal hemorrhage in young individuals, physicians often order a cerebral angiography to find the cause of cerebral aneurysm.

Answer: A. True

Explanation: Brain-meningeal hemorrhage in young people could be due to cerebral aneurysms, and cerebral angiography is needed to determine the location and size of the aneurysm.

Note:

• Cerebral angiography can detect other abnormalities such as narrowing of blood vessels, atherosclerosis, etc.

Question 20: In head injury, the best neuroimaging technique is a plain skull X-ray in anteroposterior and lateral views.

Answer: B. False

Explanation: Plain skull X-rays can only assess the skull structure and cannot detect soft tissue injuries in the brain. MRI is a superior method for evaluating brain injuries in head trauma.

Note:

• In suspected head injuries, an MRI should be performed to assess the extent of damage.