**Question:** Submucosal fibroid is detected by:

A. Transvaginal ultrasound
B. Abdominal ultrasound
C. Magnetic resonance imaging (MRI)
D. Computed tomography (CT) scan

**Core Concept:** Submucosal fibroids are benign tumors that develop within the wall of the uterus, specifically within the submucosal layer. These tumors can cause various symptoms and complications, and accurate detection is essential for proper management.

**Why the Correct Answer is Right:**

Submucosal fibroids are best detected by transvaginal ultrasound (A) due to its superior resolution and ability to visualize the uterus more accurately. The transvaginal approach allows for a close proximity between the ultrasound probe and the fibroid, enabling clear visualization and measurement of its size.

**Why Each Wrong Option is Incorrect:**

B. Abdominal ultrasound (option B) is less accurate than transvaginal ultrasound, as it has lower resolution and can be influenced by bowel gas and abdominal fat that may obscure the uterus.

C. Magnetic resonance imaging (MRI) (option C) is not the primary imaging modality for detecting submucosal fibroids. MRI is often used for assessing the extent of fibroids, evaluating surrounding tissues, and assessing the impact on surrounding organs. However, for detecting the submucosal location, ultrasound remains the primary imaging modality.

D. Computed tomography (CT) scan (option D) is primarily used for detecting tumors and assessing the extent of malignancy, rather than detecting benign uterine fibroids. CT scans are less sensitive for detecting fibroids compared to ultrasound.

**Clinical Pearl:** Transvaginal ultrasound is crucial for detecting and assessing submucosal fibroids due to its higher resolution and ability to directly visualize the uterus. If the fibroid is large or suspected to affect the uterus's shape or size, MRI can be used to provide additional information for a comprehensive evaluation.

**Correct Answer:** Transvaginal ultrasound (option A) is the correct method for detecting submucosal fibroids.