What imaging technique is recommended to determine the presence of ring-enhancing lesions in toxoplasmosis?

The recommended imaging technique to determine the presence of ring-enhancing lesions in toxoplasmosis is a head CT with contrast. This modality is particularly useful because it enhances the visualization of lesions that have increased vascular permeability, which is characteristic of toxoplasmosis.

In cases of toxoplasmosis, the lesions often appear as well-circumscribed ring-enhancing areas on CT scans, reflecting areas of inflammation and necrosis often associated with the presence of the parasite Toxoplasma gondii. The use of contrast helps to differentiate these lesions from other conditions, such as primary or metastatic brain tumors and other infectious processes.

While head CT without contrast can provide some information about the presence of lesions, it may not adequately characterize the lesions as well as CT with contrast. MRI with contrast is another valuable tool, especially in difficult cases or for better characterization of the lesions. However, for first-line imaging in a patient with suspected cerebral toxoplasmosis, head CT with contrast is typically preferred due to its availability, speed, and effectiveness in demonstrating the classic ring-enhancing lesions associated with this condition.

Ultrasound of the brain is not an appropriate imaging technique for assessing intracranial lesions in adults, as it is mainly used in pediatric populations or for specific