Professional and Linguistic Assessments Board (PLAB) Practice Exam

What imaging technique is used for the diagnosis of prolactinoma?

1. MRI

2. CT scan

3. X-ray

4. Ultrasound

The correct answer is: MRI

The choice of MRI as the imaging technique for diagnosing prolactinoma is based on its superior ability to visualize pituitary tumors. Prolactinomas, which are a type of pituitary adenoma, are best detected with MRI because it provides detailed images of soft tissues in the brain. The high-resolution images can reveal the size and extent of the tumor, as well as its relationship to surrounding structures such as the optic chiasm. While CT scans can also be used to assess pituitary tumors, MRI is preferred due to its enhanced sensitivity in detecting small lesions and its ability to provide clearer delineation of brain structures. X-rays do not provide useful information for soft tissue masses or tumors like prolactinomas, making them inappropriate for this diagnosis. Ultrasound is not a suitable imaging modality for brain tumors, as it cannot penetrate the skull effectively to provide an accurate assessment of lesions within the cranial cavity. Thus, MRI stands out as the most effective and appropriate imaging choice for diagnosing prolactinoma, due to its capacity for high-quality visualization of the pituitary gland and associated abnormalities.