Non-mass Enhancement in Breast MRI
Non-mass Enhancement in Breast MRI
Breast Magnetic Resonance Imaging (MRI) has been proven to be the most sensitive method in
 detection of breast cancer with sensitivity reaching 68-100%. The most frequent indication
 for breast MRI is screening for high-risk patients with a 20% or greater lifetime risk of
 developing breast cancer. Other indications include; assessment of extent of disease and
 screening of the contralateral breast in patients who are newly diagnosed with primary breast
 cancer. Evaluation of residual disease post Breast Conserving Surgery (BCS) with positive
 margins, loco-regional recurrence detection, as well as response to neoadjuvant chemotherapy
 are also well visualized by breast MRI. Furthermore, assessment of inconclusive mammography
 finding without a sonographic correlate, suspicious nipple discharge without a
 sono-mammographic or galacto-graphic correlate and evaluation of metastatic axillary
 lymphadenopathy in case of unknown primary tumor are all indications in which breast MRI has
 shown high sensitivity.

 Breast MRI also helps in identifying multifocal/multicentric or contralateral breast
 malignancies which was not detected by conventional imaging. Moreover, MRI gives more
 accurate data about local extension of invasive breast cancer and in situ tumors than other
 conventional modalities. In some patients newly diagnosed to have cancer breast, breast MRI
 is able to detect additional lesions that has not been found in mammography or breast
 ultrasound in 6 - 34% in the ipsilateral breast and 3 - 5% in the contralateral breast. These
 additional breast lesions are classified into focus, mass, and non-mass enhancement (NME) on
 MRI.

 Non-mass enhancement (NME) is defined as an enhancing abnormality that is not associated with
 the three-dimension volume of a mass, shape and outlining, and they are separate from the
 Background Parenchymal Enhancement (BPE). The fifth edition of the American College of
 Radiology (ACR) Breast Imaging-Reporting and Data System (BI-RADS) lexicon has erased some
 ambiguities, and modified terminologies from the fourth edition to provide more precise
 evaluation in descriptions of the distribution and Internal Enhancement Patterns (IEPs) of
 NME, contributes in quality assurance, better communication with physicians, and enhances
 patient care.

 For morphological assessment of NME, distribution is described as focal, linear, segmental,
 regional, multiple regions, and diffuse. And the IEPs are characterized as homogeneous,
 heterogeneous, clumped, and clustered ring. NME may be benign as Pseudoangiomatous Stromal
 Hyperplasia (PASH), apocrine metaplasia and radiation effect; high risk such as Atypical
 Ductal Hyperplasia (ADH), flat epithelial atypia, intraductal papilloma, radial scar or
 complex sclerosing lesion, or malignant as Ductal Carcinoma in-situ (DCIS), Invasive Ductal
 Carcinoma (IDC), and Invasive Lobular Carcinoma (ILC).
Inclusion Criteria:

 -  all female with mean age 50 ± 17 having breast MRI

 Exclusion Criteria:

 -  Contraindications of MRI as pacemakers, aneurysmal clipping, retained metallic foreign
 bodies, or claustrophobic patients

 -  Pregnant women especially in the first trimester.