Free Computed Tomography (CT Brain) Questions and Answers

Question 1

Brain non-contrast CT: Hypertension history and rapid start of left facial droop. What does the picture depict?

Accepted Answer

Intracerebral haemorrhage

Answer

The clinical presentation of hypertension and rapid onset of neurological deficits like left facial droop strongly suggests an acute stroke. On a non-contrast CT scan, acute hemorrhage appears hyperdense (bright white) due to the high protein content of fresh blood. Intracerebral hemorrhage (ICH) is bleeding directly into the brain parenchyma, often associated with uncontrolled hypertension, and would appear as a focal hyperdensity within the brain tissue.

Question 2

Poor historian, his perplexity has grown over the past few weeks. What does the picture depict?

Accepted Answer

Bilateral subdural collections

Answer

A 'poor historian' and 'perplexity growing over weeks' suggests a chronic or subacute process, which is characteristic of chronic subdural hematomas. These collections of blood or fluid accumulate slowly in the subdural space, often appearing isodense or hypodense to brain tissue on CT, and can cause gradual neurological symptoms. Bilateral collections are common, especially in elderly patients or those with brain atrophy.

Question 3

Colon cancer patient after brain contrast MRI Which diagnosis is more likely?

Accepted Answer

Two enhancing metastases

Answer

In a patient with a known history of colon cancer, the presence of new brain lesions that enhance with contrast on an MRI is highly suspicious for metastatic disease. Colon cancer frequently metastasizes to the brain. Enhancing lesions typically indicate a breakdown of the blood-brain barrier, which is common in aggressive tumors like metastases, making this the most likely diagnosis.

Question 4

Non-contrast CT brain: anticoagulated patient with right hemiparesis and abrupt onset of disorientation. What does the picture depict?

Accepted Answer

Intraventricular haemorrhage

Answer

An anticoagulated patient experiencing abrupt neurological deficits like right hemiparesis and disorientation is at high risk for intracranial hemorrhage. On a non-contrast CT, acute blood appears hyperdense (bright white). Intraventricular hemorrhage (IVH) refers to bleeding into the ventricular system of the brain, which would appear as bright, dense material filling or layering within the ventricles on the CT scan.

Question 5

The quantity of detector rows X Size of each detector is Section Width; for example, 64 x 0.625 is 40mm.

Beam Collimation/Number of Detector Rows = Detector Collimation, where 0.625 = 40 mm/64.

Accepted Answer

MSCT Beam Collimation Consists of: Beam (Formula)

Answer

This question describes the fundamental formulas used in Multi-Slice Computed Tomography (MSCT) to determine beam and detector collimation. The provided equations illustrate how the total section width is calculated from the number of detector rows and the size of each detector, and how detector collimation is derived from beam collimation. This directly relates to the technical specifications of the X-ray beam in MSCT systems.

Computed Tomography Test Practice Test

Computed Tomography Test Practice Test

Free Computed Tomography (CT Brain) Questions and Answers