**Core Concept:** Microhemorrhages are small hemorrhages within the brain tissue, usually caused by ischemic or traumatic insults. These hemorrhages can be detected using MRI sequences sensitive to detecting blood products.

**Why the Correct Answer is Right:** The correct answer, Diffusion-Weighted Imaging (DWI), is a MRI sequence that detects the restricted movement of water molecules due to cellular damage or obstruction. In the case of microhemorrhages, the presence of blood products causes a signal abnormality on DWI, making it a valuable tool for detecting these lesions.

**Why Each Wrong Option is Incorrect:**

A. Fluid-attenuated inversion recovery (FLAIR) MRI sequence is designed to detect increased signal intensity from cerebrospinal fluid (CSF) and other substances with long T2 relaxation times. It is not specific for microhemorrhages as it does not detect blood products.

B. T1-weighted imaging (T1WI) is typically used to visualize bright contrast-enhancing lesions. It is not specifically designed to detect microhemorrhages, as it lacks sensitivity to blood products.

C. T2-weighted imaging (T2WI) is used to visualize abnormalities with increased signal intensity, such as edema, inflammation, or hemorrhage. However, T2WI is not specific to microhemorrhages, as it can also show other types of abnormalities like edema or inflammation.

D. Susceptibility-weighted imaging (SWI) is a sensitive MRI sequence for detecting hemosiderin deposition, which is a product of blood breakdown. SWI is helpful in detecting microhemorrhages, making it the correct answer.

**Clinical Pearl:** Susceptibility-weighted imaging (SWI) is a valuable tool for diagnosing microhemorrhages, as it can detect hemosiderin deposition, a product of blood breakdown. FLAIR, T1WI, and T2WI are not specific for microhemorrhages as they lack sensitivity to blood products. DWI is also not specific as it does not detect blood products.