## 1 Introduction
### Applications of Breast MRI  
To reduce the number of fatalities, it is essential to enhance both screening and treatment methods. The intrinsic diversity of breast cancer necessitates increasingly tailoredtherapies to effectively lower mortality rates and improve patients' quality of life. Mammography is the most common screening procedure worldwide and has been shown to reduce mortality by approximately 19% [3]. To enhance accuracy and reduce false positives, additional imaging techniques such as MRI and ultrasound are frequently used. The role of MRI has become increasingly significant in screening, staging, and treatment monitoring, especially in cases where mammography is less effective, such as in individuals with dense breast tissue and younger women carrying BRCA gene mutations [4]. MRI is a valuable alternative because it is independent of tissue density, offers higher sensitivity, and does not involve ionising radiation. Breast MRI has emerged as a crucial tool for high-risk screening, assessing unknown primary cancers, identifying bilaterality and multicentricity, distinguishing scar tissue from local recurrences, checking implant integrity, monitoring the response to neoadjuvant chemotherapy (NAC), and determining tumour size and extent, thereby aiding in surgical planning [5]. In particular, contrast-enhanced MRI can capture detailed tumour characteristics by highlighting the tumour's neo-angiogenesis, blood vessel formation with increased permeability, which is responsible for the uptake and washout patterns of gadolinium-based contrast agents. MRI thus has interesting predictive capabilities regarding biological behaviour, as early changes in intracellular metabolism can provide valuable insights for estimating treatment response [4]. Dynamic contrast-enhanced (DCE) MRI has demonstrated potential in extracting functional parameters to assess and optimise treatment strategies for neoadjuvant chemotherapy [6]. Specifically, changes in tumour size and the apparent diffusion coefficient (ADC) have proven to be reliable predictors of pathological complete response (pCR) in NAC, which is used to reduce tumour size before surgery [7]. The basic protocol for breast MRI involves the dynamic T1-weighted (T1w) contrast-enhanced sequence. However, increasingly, a multiparametric approach is being adopted in routine practice, incorporating T2-weighted (T2w) and diffusion-weighted imaging (DWI) alongside the standard sequence. Image acquisition typically occurs in the axial plane, providing comprehensive visualisation of both breasts [8]. T1w images are taken both before and after the administration of a contrast agent. Lesion detection generally occurs 60-90 s after contrast injection, as most lesions show enhancement during this period. When fat suppression is not used, subtraction of pre- and post-contrast images is necessary to accurately identify cancerous sites. For detection purposes, two time points are usually sufficient. Differentiating between malignant and benign lesions involves analysing time-intensity curves, obtained by acquiring multiple T1w images over 5-7 min post-contrast injection. Benign lesions typically show a persistent increase in signal intensity, whereas malignant lesions often exhibit a washout or plateau pattern. T2w imaging, both with and without fat suppression, allows for the identification of cysts and detailed lesion morphology, enhancing the differentiation between benign and malignant lesions based on signal intensity. Complementing this, DWI measures the movement of water molecules and uses the ADC to further differentiate breast lesions. Malignant lesions generally exhibit low ADC values due to restricted water diffusion, which correlates with lower signal intensity [8]. Apart from malignant and benign lesions, breast lesions can be discriminated in terms of morphological features, with mass, focus/foci, and non-mass enhancements.