Ultrasound visibility of select breast biopsy markers for targeted axillary node localization following neoadjuvant treatment: simulation using animal tissue models.

PURPOSE: To compare ultrasound visibility of selected biopsy markers in animal tissue models simulating axillary echotexture. METHODS: Four breast biopsy markers were selected based on size, shape, and composition and compared to an institutional standard for testing in beef steak and pork loin phantoms. BD® UltraCor™ Twirl™; Hologic® Tumark® Professional series Q, Vision, and X; and BD® UltraClip™ Dual Trigger wing-shaped (institutional standard) biopsy markers were deployed at superficial (0-2.0 cm) and deep (2.1-4.0 cm) depths in the animal models. An animal model without a biopsy marker served as control. Four participating breast imagers blinded to marker shape and location assessed ultrasound visibility of each biopsy marker using a handheld 5-12 MHz linear array transducer with a 4-point grading system (0, not visible; 1, unsure if visible; 2, visible with difficulty; 3, definite visibility). Each breast imager was asked to select the three most easily visualized biopsy markers. RESULTS: Total visibility scores with the four-point grading system demonstrate highest score for the Twirl™ (48/48 points), followed by the Tumark® Q (42/48) and Tumark® Vision (41/48) biopsy markers. Overall individual accuracy scores across all biopsy marker types ranged from 83.3 to 95.8%. Visibility scores based on subjective radiologist assessment also demonstrate the highest vote for the Twirl™ (11), followed by the Tumark® Vision (7) and Tumark® Q (6) biopsy markers. The wing-shaped biopsy marker had the lowest visibility and voter score. CONCLUSION: The Twirl™ followed by the Tumark® Q and Vision biopsy markers demonstrates the highest visibility scores using a four-point grading system and by radiologist vote.

Breast MRI screening for average-risk women: A monte carlo simulation cost-benefit analysis.

BACKGROUND: Screening high-risk women for breast cancer with MRI is cost-effective, with increasing cost-effectiveness paralleling increasing risk. However, for average-risk women cost is considered a major limitation to mass screening with MRI. PURPOSE: To perform a cost-benefit analysis of a simulated breast cancer screening program for average-risk women comparing MRI with mammography. STUDY TYPE: Population simulation study. POPULATION/SUBJECTS: Five million (M) hypothetical women undergoing breast cancer screening. FIELD STRENGTH/SEQUENCE: Simulation based primarily on Kuhl et al8 study utilizing 1.5T MRI with an axial bilateral 2D multisection gradient-echo dynamic series (repetition time / echo time 250/4.6 msec; flip angle, 90°) with a full 512 × 512 acquisition matrix and a sensitivity encoding factor of two, performed prior to and four times after bolus injection of 0.1 mmol of gadobutrol per kg of body weight (Gadovist; Bayer, Germany). An axial T2 -weighted fast spin-echo sequence with identical anatomic parameters was also included. ASSESSMENT: A Monte Carlo simulation utilizing Medicare reimbursement rates to calculate input variable costs was developed to compare 5M women undergoing breast cancer screening with either triennial MRI or annual mammography, 2.5M in each group, over 30 years. STATISTICAL TESTS: Expected recall rates, BI-RADS 3, BI-RADS 4/5 cases and cancer detection rates were determined from published literature with calculated aggregate costs including resultant diagnostic/follow-up imaging and biopsies. RESULTS: Baseline screening of 2.5M women with breast MRI cost $1.6 billion (B), 3× higher than baseline mammography screening ($0.54B). With subsequent screening, MRI screening is more cost-effective than mammography screening in 24 years ($13.02B vs. $13.03B). MRI screening program costs are largely driven by cost per MRI exam ($549.71). A second simulation model was performed based on MRI Medicare reimbursement trends using a lower MRI cost ($400). This yielded a cost-effective benefit compared to mammography screening in less than 6 years ($3.41B vs. $3.65B), with over a 22% cost reduction relative to mammography screening in 12 years and reaching a 38% reduction in 30 years. DATA CONCLUSION: Despite higher initial cost of a breast MRI screening program for average-risk women, there is ultimately a cost savings over time compared with mammography. This estimate is conservative given cost-benefit of additional/earlier breast cancers detected by breast MRI were not accounted for. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 6 J. Magn. Reson. Imaging 2019.

Application of basic physics principles to clinical neuroradiology: differentiating artifacts from true pathology on MRI.

OBJECTIVE: This article outlines artifactual findings commonly encountered in neuroradiologic MRI studies and offers clues to differentiate them from true pathology on the basis of their physical properties. Basic MR physics concepts are used to shed light on the causes of these artifacts. CONCLUSION: MRI is one of the most commonly used techniques in neuroradiology. Unfortunately, MRI is prone to image distortion and artifacts that can be difficult to identify. Using the provided case illustrations, practical clues, and relevant physical applications, radiologists may devise algorithms to troubleshoot these artifacts.

Application of basic principles of physics to head and neck MR angiography: troubleshooting for artifacts.

Neurovascular imaging studies are routinely used for the assessment of headaches and changes in mental status, stroke workup, and evaluation of the arteriovenous structures of the head and neck. These imaging studies are being performed with greater frequency as the aging population continues to increase. Magnetic resonance (MR) angiographic imaging techniques are helpful in this setting. However, mastering these techniques requires an in-depth understanding of the basic principles of physics, complex flow patterns, and the correlation of MR angiographic findings with conventional MR imaging findings. More than one imaging technique may be used to solve difficult cases, with each technique contributing unique information. Unfortunately, incorporating findings obtained with multiple imaging modalities may add to the diagnostic challenge. To ensure diagnostic accuracy, it is essential that the radiologist carefully evaluate the details provided by these modalities in light of basic physics principles, the fundamentals of various imaging techniques, and common neurovascular imaging pitfalls.

Multimodality imaging of the postpartum or posttermination uterus: evaluation using ultrasound, computed tomography, and magnetic resonance imaging.

Postpartum and posttermination complications are common causes of morbidity and mortality in women of reproductive age. These complications can be broadly categorized into vascular, infectious, surgical, and neoplastic etiologies, or are due to ectopic implantation of placental or endometrial tissue. Causes of postpartum vascular complications include retained products of conception, arteriovenous malformation, and pseudoaneurysm. Infectious entities include endometritis, abscess, wound cellulitis, and pelvic septic thrombophlebitis. Postsurgical complications include uterine scar dehiscence, bladder flap hematoma, and subfascial hematoma. Neoplastic complications include the spectrum of gestational trophoblastic neoplasms. Ectopic tissue implantation complications include abnormal placentation and uterine scar endometriosis. Imaging is essential for diagnosis, and radiologists must be familiar with and aware of these entities so that accurate treatment and management can be obtained. In this review, we illustrate the imaging findings of common postpartum and posttermination complications on ultrasound, computed tomography, and magnetic resonance imaging.

Sterile brain abscess due to juvenile xanthogranuloma: DWI characteristics.

Juvenile xanthogranuloma (JXG) is a disorder of non-Langerhans cell histiocytosis that usually displays as a self-limiting course in children. Rare systemic involvement implies poor prognosis. Although conventional and spectroscopic magnetic resonance imaging (MRI) findings of JXG in CNS have been described, diffusion imaging of intracranial JXG has not been reported. Our case report is the first manuscript to describe diffusion restriction of a cerebral lesion seen in the setting of JXG. Since diffusion restriction has not been described in the setting of JXG but it is more commonly associated with infectious cerebral abscess, this finding has had significant impact in the management. Central nervous system (CNS) lesion of our patient has also had additional imaging features similar to typical infectious cerebral abscess. Extensive work-up has been unrevealing any infectious source. Patient has had biopsy proven peripheral sterile abscesses. After extensive discussion with the family, brain biopsy is deferred. Intravenous steroid therapy is initiated in intensive care setting. All of the lesions have gradually responded to steroid therapy. CNS lesion has taken the longest time to clear.