**Core Concept:** Liver Metastases and Computed Tomography (CECT)

Liver metastasis refers to the spread of cancer cells from a primary tumor to the liver, leading to the formation of secondary tumors. Computed Tomography (CECT) is a medical imaging technique that uses X-rays and computer algorithms to create detailed images of internal organs and structures, including the liver.

**Why the Correct Answer is Right:**
The correct answer is "C. Size of liver metastasis that can be detected by CECT is ≥ 1 cm."

In clinical practice, the detection of liver lesions, including liver metastases, is dependent on their size. Smaller lesions may be difficult to visualize on imaging modalities due to their size, which can lead to misdiagnosis or missed diagnosis. A lesion size of 1 cm or more is typically considered a threshold for detection with CECT.

**Why Each Wrong Option is Incorrect:**

A. Liver lesions smaller than 1 cm are more challenging to detect with CECT. While lesions smaller than 1 cm may still be visible on advanced imaging techniques, they are more likely to be missed or misinterpreted.

B. The size of liver lesions does not directly determine their visibility on CECT. Other factors, such as contrast enhancement and lesion location, also play a significant role in lesion detection.

C. Detecting liver lesions is not solely dependent on lesion size. Other factors contribute to the visibility of liver lesions on CECT, such as contrast enhancement and lesion location.

D. Liver lesions smaller than 1 cm may be visible on CECT but are more likely to be missed or misinterpreted due to their size.

**Clinical Pearl:**

Understanding the limitations of imaging modalities and their detection criteria is crucial for accurate diagnosis and treatment planning. In the case of liver lesions, it is essential to consider factors like size, contrast enhancement, and location in interpreting CECT findings.

**Correct Answer:**

C. Size of liver lesions ≥1 cm can be detected by CECT. Detecting liver lesions depends not only on their size but also on factors like contrast enhancement and lesion location. Liver lesions smaller than 1 cm may still be visible on CECT but are more likely to be missed or misinterpreted due to their size. A lesion size of 1 cm or more is typically considered a threshold for detection with CECT.