Imaging The Breast 2024-2025 PDF

College of Medical and Health Technology Department of Radiology Techniques 3th Academic Special Radiological Procedures 2024-2025 lecture 3: METHODS OF IMAGING THE BREAST Hayder Suhail Najm, Med...

College of Medical and Health Technology Department of Radiology Techniques 3th Academic Special Radiological Procedures 2024-2025 lecture 3: METHODS OF IMAGING THE BREAST Hayder Suhail Najm, Medical Imaging Technology, PhD  METHODS OF IMAGING THE BREAST 1. Mammography 2. Ultrasound (US) 3. Magnetic resonance imaging (MRI) 4. Radionuclide imaging 5. Imaging-guided biopsy/preoperative localization  MAMMOGRAPHY  Screening mammography is a specific type of breast imaging that uses low-dose X-rays to detect cancer early – before women experience symptoms – when it is most treatable. o Generally, there are two types of mammography: screening and diagnostic. o Mammography differs significantly in many respects from the rest of diagnostic imaging. Indications 1. Focal signs in women aged ≥40 years in the context of triple (i.e. clinical, radiological, and pathological). 2. Following a diagnosis of breast cancer, to exclude multifocal/ multicentric/bilateral disease. 3. Screening of women with a moderate/high risk of familial breast cancer who have undergone genetic risk assessment in accordance with National Institute for Health and Clinical Excellence (NICE) guidance. 4. Screening of a cohort of women who underwent the historical practice of mantle radiotherapy for treatment of Hodgkin’s disease when younger than 30 years. 5. Investigation of metastatic malignancy of unknown origin.  Equipment o Conventional film-screen mammographic technology has been superseded by full- field digital mammography (FFDM), which has a higher sensitivity in: 1. women aged younger than 50 years 2. pre/perimenopausal women 3. women with dense fibroglandular breast tissue Developments of FFDM include the following: 1. Tomosynthesis creates a single 3D image of the breast by combining data from a series of 2D radiographs acquired during a single sweep of the X- ray tube. This technique has a proven significantly increased accuracy in the morphological and margin extent analysis allows more precise assessment of tumor size, both in fatty and dense breast tissue, confirming its role in diagnostic symptomatic and screening practice. 2. Contrast-enhanced digital mammography (i.e. angiomammography). Two approaches are available: temporal sequencing (in which images pre- and postcontrast are subtracted with a resultant angiomammogram) and dual-energy imaging (in which imaging at low and high energies detailing parenchyma and fat, respectively, with and without iodine are obtained). The subsequent views can then be subtracted. 3. Computer-aided detection (CAD): uses software to detect area of clinical significance and highlight them for better output image. Technique  The standard mammographic examination comprises imaging of both breasts in two views 1. mediolateral oblique (MLO), 2. craniocaudal (CC) positions.  Screening methodology is bilateral, two-view (MLO and CC) mammography at all screening rounds.  Additional views may be required to provide adequate visualization of specific anatomical sites: MLO CC 1. true lateral view - 90º view o mediolateral view - ML view o lateromedial view - LM view 2. Lateral/medial extended CC 3. Axillary tail view. 4. magnification view(s): is performed to evaluate and count microcalcifications and their extension (as well the assessment of the borders and the tissue structures of a suspicious area or a mass) by using a magnification device which brings the breast away from the film plate and closer to the x-ray source. This allows the acquisition of magnified images (1.5x to 2x magnification) of the region of interest. Compression of the breast is an integral part of mammographic imaging resulting in: 1. reduction in radiation dose. 2. immobilization of the breast, thus reducing blurring. 3. uniformity of breast thickness, allowing even penetration. 4. reduction in breast thickness, thus reducing scatter/noise achieving higher resolution. Adaptation of the technique can provide additional information: 1. Spot compression, to remove overlapping composite tissue. 2. Magnification (smaller focal spot combined with air gap), to provide morphological analysis.  ULTRASOUND Indications: 1. Focal signs in women younger than 40 years. 2. Following a diagnosis of breast cancer to assess initial tumor size or response to neoadjuvant therapy 3. Targeting diagnostic biopsy/preoperative localization of both palpable and impalpable breast lesions 4. To guide axillary lymph node biopsy, thus informing choice of surgical management.  Ongoing studies demonstrate the potential to improve diagnostic accuracy with the inclusion of contrast-enhanced techniques using microbubbles. Not Indicated: 1. For screening in any age group 2. In the investigation of generalized signs/symptoms—e.g. cyclical mastalgia or nonfocal pain/lumpiness 3. In the routine investigation of gynaecomastia Equipment: o Hand-held, high-frequency (–18 MHz) contact US is widely used in breast imaging. o Proprietary standoff gels can be useful when assessing superficial lesions and the nipple-areolar complex.  Technique: 1. The patient’s arm on the side to be examined should be placed behind the head. 2. The patient lies supine for examination of the medial aspect of the breast. 3. The patient lies in the lateral, oblique position for examination of the lateral and axillary aspects of the breast and axilla. Additional Technique: o Elastography is a noninvasive US technique, which provides a visual representation of the stiffness (elasticity) of both normal and abnormal tissue. o US imaging is used to examine tissue, both before and after minimal compression. o A colour-coded image is generated with dark tissue representing least compressible tissue—i.e. with a higher index of suspicion of malignancy.  MAGNETIC RESONANCE IMAGING Indications: 1. Detection/exclusion of recurrent malignant disease in the conserved breast ≥6 months following surgery. 2. Monitoring response to neoadjuvant therapy 3. In carefully selected cases, to clarify equivocal or suspicious mammographic and US findings 4. Investigation of occult breast cancer; 0.3% of patients present with malignant axillary lymphadenopathy but normal breast triple assessment 5. MRI may have a role in the preoperative evaluation of the extent of high-grade (Grade 3) ductal carcinoma in situ (DCIS). MRI may be used as a screening test for women who have a high risk of breast cancer. Factors that put women at high risk include the following:  Certain gene changes, such as changes in the BRCA1 or BRCA2 genes.  A family history (first-degree relatives, such as a mother, daughter, or sister) with breast cancer.  Certain genetic syndromes, such as Li-Fraumeni or Cowden syndrome. Contraindications for Breast MRI scan:  Any electrically, magnetically or mechanically activated implant (e.g. cardiac pacemaker, insulin pump biostimulator, neurostimulator, cochlear implant, and hearing aids)  Intracranial aneurysm clips (unless made of titanium)  Pregnancy (risk vs benefit ratio to be assessed)  Ferromagnetic surgical clips or staples  Metal shrapnel or bullet Patient preparation for breast MRI scan:  An intravenous line must be placed with extension tubing extending out the magnetic bore  gown is worn correctly as the patient will be lying face down with the gown open to position the breast in the coil.  Gadolinium should only be given to the patient if GFR is > 30 Technique: 1. Contraindications as for standard MRI examinations 2. Lying prone, with breasts placed in a dedicated surface coil, images are obtained pre and post-contrast (0.1– 0.2 mmol kg−1 gadolinium chelate contrast, given i.v. via pump injector) in either axial fat suppression or coronal subtraction sequences. The presence, degree, speed and morphology of the pattern of enhancement are analyzed. 3. For implant integrity, nonenhanced scanning is adequate.  Why is MRI considered better than other diagnostic modalities? o The MRI, unlike physical exams and mammograms, can differentiate fibrosis and tumor tissue from dense breasts. It gives a more accurate picture of the size of the tumor and is more accurate than ultrasound, mammography, or a physical exam after neoadjuvant chemotherapy. In MRI there are a lot of examination sequences: 1. Dynamic contrast-enhanced MRI (DCE-MRI) helps in the detection and characterization of breast lesions, especially in cases where mammography or ultrasound may not provide sufficient information. DCE-MRI can help differentiate between benign and malignant lesions, assess tumor size, determine the extent of disease, and evaluate treatment response. 2. Diffusion-Weighted Imaging (DWI) : This technique evaluates the movement of water molecules in tissue. Breast imaging, it can help assess the cellularity of lesions, as malignant tumors typically restrict water movement more than benign lesions.  A B MRI, DCE sequence, first phase after contrast injection. patient 52 years with left breast cancer {Ductal Carcinoma in Situ (DCIS)}, (A) represents the patient's pre-chemotherapy treatment, and (B) post- chemotherapy after 6 cycles, and has got a complete response to chemotherapy. Positron Emission Tomography Scanning o Hybrid positron emission tomography (PET)-CT scanning with 18F-fluorodeoxyglucose (FDG) may provide additional information in carefully selected cases where restaging of disease, monitoring response to treatment or the detection of distant metastases are required.