Hologic I-View Contrast-Enhanced Mammography: CEM Technology Guide

Contrast-enhanced mammography is one of the most significant clinical advances in breast imaging in recent years. Hologic I-View is a contrast-enhanced spectral mammography (CEM) technology that combines the accessibility and workflow familiarity of mammography with the functional information that has traditionally required breast MRI. By revealing areas of abnormal neovascularity associated with malignant tumors, I-View CEM provides clinically valuable information that standard mammography and tomosynthesis cannot offer on their own.

This guide covers the technical principles behind I-View contrast-enhanced mammography, the clinical procedure, indications and applications, comparison to breast MRI, hardware requirements, system compatibility, and the growing adoption trend driving interest in CEM across breast imaging programs nationwide.

What Is Hologic I-View Contrast-Enhanced Mammography?

I-View is Hologic's contrast-enhanced mammography (CEM) technology, available as a software and hardware module on compatible Selenia Dimensions and 3Dimensions systems. I-View uses a dual-energy acquisition technique performed after intravenous administration of an iodinated contrast agent to generate subtraction images that highlight areas of contrast uptake in the breast.

The fundamental principle is the same as contrast-enhanced breast MRI: malignant tumors develop abnormal blood vessel networks (neovascularity or angiogenesis) that take up and retain contrast agent differently than normal breast tissue. By imaging the breast at two different X-ray energy levels immediately after contrast injection, I-View can isolate the contrast signal from the background breast tissue, producing a subtraction image that reveals areas of enhancement corresponding to regions of increased vascularity.

How the I-View Procedure Works

The I-View CEM examination follows a specific protocol that integrates contrast administration with a timed mammographic acquisition sequence:

• Patient preparation: An intravenous catheter is placed in the patient's arm, similar to the preparation for a CT scan with contrast or a breast MRI. The patient's renal function and allergy history are reviewed per institutional protocol for iodinated contrast administration.
• Contrast injection: A standard iodinated contrast agent (the same type used in CT imaging) is administered intravenously, typically at a dose of 1.5 mL per kilogram of body weight. The contrast agent circulates through the bloodstream and accumulates in areas of increased vascularity.
• Timed acquisition: Beginning approximately two minutes after contrast injection, the technologist acquires dual-energy mammographic images of each breast. Each acquisition consists of a low-energy exposure (standard mammographic energy range) and a high-energy exposure (above the k-edge of iodine at 33.2 keV) in rapid succession during a single compression.
• Image processing: The I-View software performs a weighted logarithmic subtraction of the low-energy and high-energy images. The low-energy image represents normal mammographic tissue contrast. The high-energy image captures both tissue and iodine contrast. The subtraction process removes the tissue signal, leaving only the iodine contrast enhancement visible on the final subtraction image.
• Image presentation: The radiologist reviews both the standard low-energy mammographic images (which are equivalent to a conventional mammogram) and the recombined subtraction images that show contrast enhancement. The standard images provide structural and morphological information, while the subtraction images provide functional information about tissue vascularity.

Clinical Applications of I-View CEM

I-View contrast-enhanced mammography serves several important clinical roles in breast imaging practice:

Supplemental Screening for High-Risk Patients

Women at elevated risk for breast cancer, including those with genetic mutations (BRCA1, BRCA2), strong family histories, prior chest radiation therapy, or lifetime risk assessments above 20%, benefit from supplemental screening beyond standard mammography. Breast MRI has been the traditional supplemental screening tool for this population, but access barriers including limited MRI availability, high cost, long examination times, and patient claustrophobia limit its utilization. I-View CEM provides an accessible alternative that delivers functional vascular information in a mammographic workflow that takes approximately 10 minutes compared to 30 to 45 minutes for breast MRI.

Extent of Disease Evaluation

For patients with newly diagnosed breast cancer, understanding the full extent of disease in the affected breast and screening the contralateral breast for synchronous malignancy is essential for surgical planning. I-View CEM can map the extent of enhancing disease, identify satellite lesions, and detect contralateral cancers with sensitivity approaching that of breast MRI. This information directly impacts surgical decision-making, helping surgeons determine whether breast-conserving surgery is feasible or whether mastectomy is more appropriate.

Problem-Solving Tool

I-View CEM serves as a valuable problem-solving tool for inconclusive findings on standard mammography or ultrasound. When a mammographic finding is equivocal and the clinical question is whether the finding represents a vascularized lesion or a benign tissue overlap, contrast enhancement information can provide the additional diagnostic clarity needed to determine the appropriate management recommendation.

Neoadjuvant Chemotherapy Response Monitoring

For patients undergoing neoadjuvant chemotherapy prior to surgery, monitoring tumor response to treatment is important for guiding clinical decisions. I-View CEM can assess changes in tumor enhancement between treatment cycles, providing information about treatment response that complements clinical examination and ultrasound assessment.

I-View CEM Compared to Breast MRI

The comparison between contrast-enhanced mammography and breast MRI is clinically important because both modalities provide functional vascular information about breast lesions. Understanding their relative strengths helps facilities determine how to position CEM within their breast imaging service line:

• Accessibility: CEM is performed on the mammography unit that is already present in the breast imaging department. It does not require a dedicated MRI scanner, specialized breast coils, or MRI-specific scheduling infrastructure. This makes CEM far more accessible, particularly for facilities that do not have on-site MRI or face long MRI scheduling backlogs.
• Examination time: A complete bilateral I-View CEM examination takes approximately 7 to 10 minutes of acquisition time after contrast injection, compared to 30 to 45 minutes for a bilateral breast MRI. This time advantage improves patient throughput and reduces the scheduling burden associated with supplemental screening programs.
• Patient tolerance: CEM is performed with the patient standing or sitting at a standard mammography unit. There is no enclosed bore, no loud gradient noise, and no requirement to lie prone for an extended period. For patients who experience claustrophobia, anxiety, or physical discomfort with MRI, CEM offers a substantially more tolerable examination experience.
• Cost: CEM is significantly less expensive than breast MRI, both in terms of equipment capital cost and per-examination operational cost. This cost advantage makes supplemental screening with CEM financially viable for patient populations and practice settings where breast MRI would be cost-prohibitive.
• Spatial resolution: CEM produces images with the high spatial resolution characteristic of mammography. Fine calcification morphology is visible on the low-energy images, which is information that breast MRI cannot provide. This dual capability of structural and functional information on the same examination is a unique advantage of CEM.
• Sensitivity and specificity: Published studies comparing CEM to breast MRI for cancer detection have shown CEM sensitivity in the range of 90 to 95 percent, which approaches the sensitivity of breast MRI. Specificity of CEM is generally comparable to or slightly better than breast MRI in some studies, meaning CEM may generate fewer false-positive findings that lead to unnecessary biopsies.

I-View Hardware Requirements

Enabling I-View CEM on a Hologic mammography system requires both software licensing and specific hardware components:

• Dual-energy capable X-ray generator: The system's X-ray generator must be capable of producing rapid sequential exposures at two different energy levels (low-energy and high-energy) during a single compression. The high-energy exposure must be above the k-edge of iodine to achieve adequate contrast agent visibility.
• Compatible detector: The detector must be capable of handling the dual-energy acquisition sequence with appropriate frame rates and readout speeds.
• I-View software license: The I-View software module must be licensed and installed on the acquisition workstation. This software controls the dual-energy acquisition protocol, performs the subtraction processing, and presents the standard and subtraction images in the appropriate reading format.
• Contrast injector interface: While contrast can be injected manually, many facilities integrate a power injector with the I-View workflow for standardized contrast delivery. The system interface supports injector communication for coordinated timing.

Which Systems Support I-View?

I-View CEM is available on the following Hologic platforms:

• Hologic 3Dimensions (Genius): I-View is available as an add-on module on the 3Dimensions platform. The 3Dimensions system's hardware architecture is designed to support the dual-energy acquisition requirements of I-View.
• Hologic Selenia Dimensions (select configurations): I-View is available on certain Dimensions configuration tiers, typically the higher-end systems with the necessary generator and detector capabilities. Not all Dimensions tiers support I-View; eligibility depends on the specific hardware configuration.

Facilities considering I-View should have their system evaluated by a qualified service provider to confirm I-View compatibility and identify any hardware or software prerequisites that must be met before the module can be activated.

Growing Adoption of Contrast-Enhanced Mammography

CEM adoption has accelerated significantly in recent years as clinical evidence, reimbursement pathways, and awareness among breast imaging specialists have expanded. Several factors are driving this trend:

• Clinical evidence maturation: A growing body of peer-reviewed literature demonstrates CEM's clinical value across screening, diagnostic, and staging applications, giving imaging directors confidence to invest in the technology.
• Reimbursement improvements: CEM-specific CPT codes and improved payer coverage have made the procedure financially viable for a broader range of practice settings.
• Dense breast notification laws: Legislation in many states requiring facilities to notify patients about breast density and inform them of supplemental screening options has increased demand for accessible supplemental screening tools. CEM fills a critical gap between standard mammography and breast MRI.
• Breast center differentiation: Facilities that offer CEM can differentiate their breast imaging services in competitive markets, attracting patients and referrals by providing advanced imaging capabilities that may not be available at nearby competitors.

ARRAD's I-View CEM Support

ARRAD supports Hologic I-View contrast-enhanced mammography from initial feasibility assessment through installation, calibration, and ongoing service. Our team can evaluate your existing Hologic system's compatibility with I-View, coordinate the necessary hardware and software components, and manage the complete installation process to bring CEM capability to your breast imaging practice.

For facilities purchasing new or refurbished Hologic systems, ARRAD can configure your system with I-View capability included, ensuring your breast center is equipped for contrast-enhanced imaging from the start.

Contact ARRAD at 877.299.8303 to discuss I-View CEM for your facility, or request a consultation online. Learn more about our Hologic service expertise on our Hologic service page. OEM parts and accessories are available through radmedparts.com.